Sex- and habitat-specific responses of a high arctic willow, Salix arctica, to experimental climate change

Energy Technology Data Exchange (ETDEWEB)

Jones, M.H.; Macdonald, S.E. [Univ. of Alberta, Dept. of Renewable Resources, Edmonton, AB (Canada); Henry, G.H.R. [Univ. of British Columbia, Dept. of Geography, Vancouver, BC (Canada)

1999-10-01

Dioecious plant species and those occupying diverse habitats may present special analytical problems to researchers examining effects of climate change. Here we report the results from two complementary studies designed to determine the importance of sex and habitat on gas exchange and growth of male and female individuals of a dioecious, circumpolar willow, Salix arctica, in the Canadian High Arctic. In field studies, male and female willows from dry and wet habitats were subjected to passively enhanced summer temperature ({approx} to 1.3 deg C) using small open-top chambers over three years. Peak season gas exchange varied significantly by willow sex and habitat. Overall net assimilation was higher in the dry habitat than in the wet, and higher in females than in males. In the dry habitat, net assimilation of females was enhanced by experimental warming, but decreased in males. In the wet habitat, net assimilation of females was substantially depressed by experimental warming, while males showed an inconsistent response. Development and growth of male and female catkins were enhanced by elevated temperature more than leaf fascicles, but leaf fascicle development and growth varied more between the two habitats, particularly in males. In a controlled environment study, male and female willows from these same wet and dry habitats were grown in a 2x2 factorial experiment including 1 x or 2 x ambient [CO{sub 2}] and 5 or 12 deg. C. The sexes responded very differently to the experimental treatments, but we found no effect of original habitat. Net assimilation in males was affected by the interaction of temperature and CO{sub 2}, but in females by CO{sub 2} only. Our results demonstrate (a) significant intraspecific and intersexual differences in arctic willow physiology and growth, (b) that these differences are affected by environmental conditions expected to accompany global climate change, and (c) that sex- and habitat-specific responses should be explicitly

Phytotoxicity of polycyclic aromatic hydrocarbons to willow trees

DEFF Research Database (Denmark)

Thygesen, R.S.; Trapp, Stefan

2002-01-01

The toxicity of PAH to willow trees (Salix alba, S. viminalis, S. viminalisx;schwerinii) was investigated. Willow cuttings were grown in PAH-saturated hydroponic solution (naphthalene NAP, phenanthrene PHEN and benzo(a)pyrene BaP). Toxicity was related to aqueous solubility and was highest for NAP...

Response of Salix alba L. to heavy metals and diesel fuel ...

African Journals Online (AJOL)

Response of Salix alba L. to heavy metals and diesel fuel contamination. ... Ni and Pb led to reduced accumulation of Pb. Presence of 5 g/kg of diesel fuel in soil significantly increased toxic influence of applied heavy metals by further reducing ... Key words: Cd, Ni, Pb, phytoremediation, phytoextraction, willow, Salix alba.

Phytoremediation prospects of willow stands on contaminated sediment : A field trial

NARCIS (Netherlands)

Vervaeke, P; Luyssaert, S.; Mertens, J.; Meers, E.; Tack, F. M.G.; Lust, N

2003-01-01

Establishing fast growing willow stands on land disposed contaminated dredged sediment can result in the revaluation of this material and opens possibilities for phytoremediation. A field trial was designed to assess the impact of planting a willow stand (Salix viminalis L. 'Orm') on the dissipation

The potential of willow for remediation of heavy metal polluted calcareous urban soils

DEFF Research Database (Denmark)

Jensen, J K; Holm, P E; Nejrup, J

2009-01-01

Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber...

On the irrigation requirements of cottonwood (Populus fremontii and Populus deltoides var. wislizenii) and willow (Salix gooddingii) grown in a desert environment

Science.gov (United States)

Hartwell, S.; Morino, K.; Nagler, P.L.; Glenn, E.P.

2010-01-01

Native tree plots have been established in river irrigation districts in the western U.S. to provide habitat for threatened and endangered birds. Information is needed on the effective irrigation requirements of the target species. Cottonwood (Populus spp.) and willow (Salix gooddingii) trees were grown for seven years in an outdoor plot in a desert environment in Tucson, Arizona. Plants were allowed to achieve a nearly complete canopy cover over the first four years, then were subjected to three daily summer irrigation schedules of 6.20??mm??d-1; 8.26??mm??d-1 and 15.7??mm??d-1. The lowest irrigation rate was sufficient to maintain growth and high leaf area index for cottonwoods over three years, while willows suffered considerable die-back on this rate in years six and seven. These irrigation rates were applied April 15-September 15, but only 0.88??mm??d-1 was applied during the dormant period of the year. Expressed as a fraction of reference crop evapotranspiration (ETo), recommended annual water applications plus precipitation (and including some deep drainage) were 0.83 ETo for cottonwood and 1.01 ETo for willow. Current practices tend to over-irrigate restoration plots, and this study can provide guidelines for more efficient water use. ?? 2010 Elsevier Ltd.

Interaction in Short rotation coppice willow, Salix viminalis genotype mixtures

Energy Technology Data Exchange (ETDEWEB)

Begley, D. [Department of Biological Sciences, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom); McCracken, A.R. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)]|[Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Dawson, W.M. [Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Watson, S. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)

2009-02-15

Seven straight Salix viminalis genotypes with different levels of rust (Melampsora epitea) susceptibility were grown as mono-plots as well as being incorporated into a range of mixtures. Two 3-year harvests (2003 and 2006) were taken. Disease progress was followed on each of the individual genotypes throughout each growing season 2001-2006. In 2003 there were small but significant yield increases from the mixtures compared to the yield of individual components grown as mono-plots. These differences were not evident at the second harvest in 2006. No consistent effect of mixtures on reducing rust on the most susceptible genotype, Salix viminalis '77082' were observed. In some years, e.g. 2003, at certain times during the growing season, significant reductions were observed on Salix viminalis '77082' in certain 3-way mixtures compared to mono-plots. These, however, were not repeated consistently in subsequent years. It was concluded that the current commercial practice in many parts of Europe of planting mixtures as a disease control strategy will only be effective if there is sufficient genetic diversity between the Salix genotypes incorporated into the mixture. (author)

Selection of ectomycorrhizal willow genotype in phytoextraction of heavy metals.

Science.gov (United States)

Hrynkiewicz, Katarzyna; Baum, Christel

2013-01-01

Willow clones are used for the phytoextraction of heavy metals from contaminated soils and are usually mycorrhizal. The receptiveness of willow clones for mycorrhizal inoculum varies specific to genotype; however, it is unknown if this might have a significant impact on their efficiency in phytoextraction of heavy metals. Therefore, a model system with mycorrhizal and non-mycorrhizal willows of two different genotypes--one with usually stronger natural mycorrhizal colonization (Salix dasyclados), and one with lower natural mycorrhizal colonization (S. viminalis)--was investigated for its efficiency of phytoextraction of heavy metals (Cd, Pb, Cu, Zn) from contaminated soil. Inoculation with the ectomycorrhizal fungus Amanita muscaria significantly decreased the biomass of leaves of both inoculated willow clones, and increased or had no effect on the biomass of trunks and roots of S. dasyclados and S. viminalis, respectively. The concentrations of heavy metals in the biomass of S. dasyclados were in general higher than in S. viminalis irrespective of inoculation with the ectomycorrhizal fungus. Inoculation with A. muscaria significantly decreased the concentration of Cu in the trunks of both Salix taxa, but did not affected the concentrations of other heavy metals in the biomass. In conclusion, stronger receptiveness of willow clones for mycorrhizal inoculum was correlated with an increased total extraction of heavy metals from contaminated soils. Therefore, this seems to be a suitable criterion for effective willow clone selection for phytoremediation. Increased biomass production with relatively constant metal concentrations seems to be a major advantage of mycorrhizal formation of willows in phytoremediation of contaminated soils.

Preliminary tests for Salix sp. tolerance to heavy metals (Cd, Ni, Pb)

Science.gov (United States)

Corneanu, Mihaela; Hernea, Cornelia; Butnariu, Monica; Corneanu, Gabriel; Sărac, Ioan; Hollerbach, Wilhelm; Neţoiu, Constantin; Petcov, Andreea Adriana

2014-05-01

The species of Salix genus constitute potential sources of germplasm in the prevention of the environment degradation, and offer remedy for about two third from the all degradation types. The majority of the willow species, present a good adaptation to hypoxic conditions, feature which suggest that they manifest a preference for mineral nutrition in comparison with organic one. Thus, many of willow species can be developed on soils with a big amount of minerals and/or radionuclides, being both phytoremediatory species, as well as pioneer ones, contributing to the restoration of soil. Thus, the willow species, posses the capacity for development in degraded areas, natural or anthropic, as swamps, abandoning crops areas, sandy dune, riparian sandy areas, gravels, a.o. In this paper are present some laboratory comparative tests of heavy metals tolerance on four Salix sp. genotypes: clone 202 (Salix alba), hybrid 892 (Salix alba), Inger (Salix viminalis) and Gudrun (Salix viminalis). The genotypes of Salix alba are native from Romania, produced in the Forest Research and Management Institute Bucharest, while the genotypes of Salix viminalis are native from Sweden, but the plant material was produced under license in Romania by REBINA Agrar SRL. As plant material were used one-year-old cuttings (5-10 cm long), with 2-6 buds each. Per genotype, per heavy metal and each of three concentration five replication were used. There were ten experimental variants for each genotype: three concentrations for each of the heavy metals; concentrations selected, in the accordance SR ISO 11269-2/March 1999 and Control (tap water). The cuttings were maintained in metalic solutions for 15 days. In the days 7th and 15th, were performed biometrical observations on: the roots number and length, the shoots number and length, the leaves number/shoot, viability of the shoots. At the end of the experiment the content in heavy metals was determined in roots and shoots (by atomic absorption

Integrated long-term responses of an arctic-alpine willow and associated ectomycorrhizal fungi to an altered environment

DEFF Research Database (Denmark)

Clemmensen, Karina Engelbrecht; Michelsen, Anders

2006-01-01

We evaluated ectomycorrhizal (ECM) colonization and morphotype community composition together with growth response and biomass distribution in the arctic-alpine, prostrate willow Salix herbacea L. x Salix polaris Wahlenb. after 11 seasons of shading, warming, and fertilization at a fellfield...

Phytoextraction of heavy metals by willows growing in biosolids under field conditions.

Science.gov (United States)

Laidlaw, W S; Arndt, S K; Huynh, T T; Gregory, D; Baker, A J M

2012-01-01

Biosolids produced by sewage treatment facilities can exceed guideline thresholds for contaminant elements. Phytoextraction is one technique with the potential to reduce these elements allowing reuse of the biosolids as a soil amendment. In this field trial, cuttings of seven species/cultivars of Salix(willows) were planted directly into soil and into biosolids to identify their suitability for decontaminating biosolids. Trees were irrigated and harvested each year for three consecutive years. Harvested biomass was weighed and analyzed for the contaminant elements: As, Cd, Cu, Cr, Hg, Pb, Ni, and Zn. All Salix cultivars, except S. chilensis, growing in soils produced 10 to 20 t ha(-1) of biomass, whereas most Salix cultivars growing in biosolids produced significantly less biomass (metals from biosolids, driven by superior biomass increases and not high tissue concentrations. The willows were effectual in extracting the most soluble/exchangeable metals (Cd, 0.18; Ni, 0.40; and Zn, 11.66 kg ha(-1)), whereas Cr and Cu were extracted to a lesser degree (0.02 and 0.11 kg ha(-1)). Low bioavailable elements, As, Hg, and Pb, were not detectable in any of the aboveground biomass of the willows. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Initial spacing of poplars and willows grown as arable coppice

Energy Technology Data Exchange (ETDEWEB)

Armstrong, A.; Johns, C.

1997-11-01

Two clones of poplar and two clones of willow were grown at two sites, on a three year cutting cycle, at six different square spacings, between 0.8 metres and 1.5 metres. The two willow clones 'Bowles hybrid' and 'Dasyclados' were planted at both sites. The poplar clones Populus interamericana 'Beaupre' and Populus trichocarpa 'Columbia River'' were planted at Wishanger in Hampshire. The poplar clones Populus interamericana 'Boelare' and Populus trichocarpa 'Trichobel' were planted at Downham Market in Norfolk. The highest yield of 17.55 oven dry tonnes per hectare (odt/ha/annum) was obtained from 'Bowles hybrid', at the closest spacing, grown on a water meadow adjacent to the River Wey at Wishanger. The highest yield for all clones at both sites was achieved at the closest spacing (in this first rotation). There was a significant linear effect. One of the most interesting observations was that when comparing the gradient of the linear relationship, within species, the gradient was steeper for the higher yielding clone. This was particularly so for the willows. This would suggest that higher yielding clones are more tolerant of crowding, or, that upright Salix viminalis make better use of close space than the more spreading Salix dasyclados. The new Salix x Salix schwerinnii hybrids should therefore also be responsive to closer spacing. The same effect was observed for the poplars at Wishanger only, but the difference was not as dramatic. There was a suggestion from the highest yielding poplar plots that optimum yield may still be obtained at the currently recommended spacing of 1.0 metre x 1.0 metre. (author)

Yield of tannin willows on ravine areas in the Central Forest Steppe

Energy Technology Data Exchange (ETDEWEB)

Sidorov, A I

1981-01-01

A note on the performance of 12 species of willow grown in a plantation on leached chernozem soils, to provide bark rich in tannins. The plantation was established by cuttings (25 cm long) at a spacing of 2.5 x 0.5 metres for the tree willows and 2.5 x 0.75 metres for the bush willows. Bark yields were determined at 7-8 years. The greatest yields were obtained from Salix smithiana, S. stipularis and S. acuminata: 12.0, 10.8 and 10.2 t/hectare respectively. Data on tannin yields are tabulated. Fellings for bark harvesting can be made every 5 years in plantations of bush willows and every 7 years in plantations of tree willows. The plantations can be used for 30 year with bush willows and for 50 years with tree willows.

White willow sexual regeneration capacity under estuarine conditions in times of climate change

Science.gov (United States)

Markus-Michalczyk, Heike; Hanelt, Dieter; Denstorf, Julian; Jensen, Kai

2016-10-01

Tidal wetlands provide both habitats for coastal populations and wildlife, and ecosystem services for human welfare. Building with nature regarding cost-effective coastal protection is of increasing interest. Much research has been carried out on plant reproduction capacities in mangroves and salt marshes, but less is known on this issue in tidal freshwater wetlands. Willows are being successfully used for bank stabilization in riverine habitats, however, today white willow softwood forests in tidal wetlands are highly fragmented, and restoration is required e.g. by the European Habitats Directive. Recently, tolerance to increasing salinity and tidal flooding was found for vegetative propagules of floodplain willows. However, the establishment of autochthonous sexual recruits is necessary to conserve the genetic diversity of local populations, and thus may be preferable in restoration. The germination and early seedling establishment of Salix alba (white willow) was experimentally studied under simulated estuarine conditions. The species tolerance to increasing salinity (0, 0.5, 1, 1.5, and 2) was tested in a climate chamber, and its tolerance to flooding at different tidal treatments (control, spring tide, daily tide 15 min and 2 h flooding) in the greenhouse. Germination was neither affected by increasing salinity nor by tidal flooding. Salix seedlings established up to salinity 1.5, but cotyledon performance and radicle growth was largely reduced at salinity 2. Under tidal flooding, seedling growth was similar in all treatments. However, in the treatments with daily tides seedling anchorage in the substrate took more than two weeks, and fewer seedlings reached a suitable length to approach the high water line. We assess S. alba sexual regeneration under estuarine conditions as generally possible. Further studies are needed on the effects of sedimentation-erosion processes on willow establishment in the field, especially on feedbacks between Salix survival and

Wood biomass: The potential of willow

International Nuclear Information System (INIS)

White, E.H.; Abrahamson, L.P.

1991-10-01

Experiments were established in central New York State in spring, 1987, to evaluate the potential of Salix for wood biomass production using ultrashort-rotation intensive-culture techniques. Five selected willow clones and one hybrid poplar clone planted at 1 x 1 foot spacing were tested for biomass production with annual coppicing. This report presents results of this research as of December 31, 1990. (VC)

PHYTOREMEDIATION OF CHLORPYRIFOS BY POPULUS AND SALIX

OpenAIRE

Young Lee, Keum; Strand, Stuart E.; Doty, Sharon L.

2012-01-01

Chlorpyrifos is one of the commonly used organophosphorus insecticides that are implicated in serious environmental and human health problems. To evaluate plant potential for uptake of chlorpyrifos, several plant species of poplar (Populus sp.) and willow (Salix sp.) were investigated. Chlorpyrifos was taken up from nutrient solution by all seven plant species. Significant amounts of chlorpyrifos accumulated in plant tissues, and roots accumulated higher concentrations of chlorpyrifos than di...

SELECTIVE FORAGING ON WOODY SPECIES BY THE BEAVER CASTOR FIBER, AND ITS IMPACT ON A RIPARIAN WILLOW FOREST

NARCIS (Netherlands)

NOLET, BA; HOEKSTRA, A; OTTENHEIM, MM

1994-01-01

Beavers were re-introduced in the Biesbosch, The Netherlands, a wood dominated by willows Salix spp. Conservationists expected that herbivory by beavers would enhance succession to a mixed broad-leaved forest. Willows formed the staple food of the beavers, but they removed only 1.4% of the standing

Conservation assessment for the autumn willow in the Black Hills National Forest, South Dakota and Wyoming

Science.gov (United States)

J. Hope Hornbeck; Carolyn Hull Sieg; Deanna J. Reyher

2003-01-01

Autumn willow, Salix serissima (Bailey) Fern., is an obligate wetland shrub that occurs in fens and bogs in the northeastern United States and eastern Canada. Disjunct populations of autumn willow occur in the Black Hills of South Dakota. Only two populations occur on Black Hills National Forest lands: a large population at McIntosh Fen and a small...

Technique for compressed bundles for harvest of whole straw willow. Pilot study; Teknik foer komprimerande helskottsskoerd av salix i buntform. Foerstudie

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Hans (Vaesteraeng Lantbruk AB (Sweden))

2008-06-15

and demand good and secure weather conditions. Heavy rain or snow is a big problem during harvest season. The proposal from Maelarenergi AB has been carefully analysed and they think this is a solution with high potential. It should mean lower costs than in compare to using a mobile fossil driven cutter. Chipped Salix on farmland is a 'hot' flowchart, with big demand on among other things the logistic in and around the system. The possibility to direct consumption with chipped Salix has a limited storage capability. Chipped Salix is not possible to transport long distance, maximum 30 - 35 km, if it should keep the capacity to pay the procedure. The costs of transport will be too big in comparison to production value. Another advantage is the costs for intermediate storage. For example the area of the intermediate storage station, can be reduced when smaller volumes with higher density are handled. An overall analysis over the project 'Salix Maelardalen' point out very obviously that an alternative to the today direct chipping system is necessary and that development work around harvest with compressing bundle technique is very important. Big positive effects on environment can also be shown. Questions around 'compressed whole straw harvest of Willow' can be answered by a pilot study. There are o lot of aspects to pay attention to and 'smooth the road' to the growing production of Salix and it's rising as fuel raw material. The pilot study is going to penetrate the development of new harvest technique and earlier systems for 'compressed whole shoot harvest' of Salix. Needs and potential of new technique will be analysed and the study will also give suggestions to a new specification of requirements. The study will also suggest future developing projects. One of the purposes with the pilot project is that it could be a platform for future technical and practical research and even to be as a base for coming

Hydroponic screening for metal resistance and accumulation of cadmium and zinc in twenty clones of willows and poplars

International Nuclear Information System (INIS)

Santos Utmazian, Maria Noel dos; Wieshammer, Gerlinde; Vega, Rosa; Wenzel, Walter W.

2007-01-01

We screened 20 different clones of willow and poplar species in hydroponic experiments for their metal resistance and accumulation properties. Plants were exposed for 4 weeks either to single additions of (μM) 4.45 Cd or 76.5 Zn, or a metal cocktail containing the same amounts of Cd and Zn along with 7.87 Cu and 24.1 Pb. Plant biomass, metal tolerance and metal accumulation pattern in roots and leaves varied greatly between clones. The leaf:root ratio of metal concentrations was clearly underestimated compared to soil experiments. The largest metal concentrations in leaves were detected in Salix dasyclados (315 mg Cd kg -1 d.m.) and a Salix smithiana clone (3180 mg Zn kg -1 d.m.) but these species showed low metal tolerance. In spite of smaller Cd and Zn concentrations, the metal-tolerant clones Salix matsudana, Salix fragilis-1, and Salix purpurea-1 hold promise for phytoextraction as they produced large biomass and metal contents in leaves. - Hydroponically grown willows and poplar clones accumulate up to (mg kg -1 d.w.) 315 Cd and 3180 Zn in leaves

Hydroponic screening for metal resistance and accumulation of cadmium and zinc in twenty clones of willows and poplars

Energy Technology Data Exchange (ETDEWEB)

Santos Utmazian, Maria Noel dos [Department of Forest- and Soil Sciences, University of Natural Resources and Applied Life Sciences, Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna (Austria); Wieshammer, Gerlinde [Department of Forest- and Soil Sciences, University of Natural Resources and Applied Life Sciences, Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna (Austria); Vega, Rosa [Department of Forest- and Soil Sciences, University of Natural Resources and Applied Life Sciences, Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna (Austria); Wenzel, Walter W. [Department of Forest- and Soil Sciences, University of Natural Resources and Applied Life Sciences, Vienna, Peter-Jordan-Strasse 82, A-1190 Vienna (Austria)]. E-mail: walter.wenzel@boku.ac.at

2007-07-15

We screened 20 different clones of willow and poplar species in hydroponic experiments for their metal resistance and accumulation properties. Plants were exposed for 4 weeks either to single additions of ({mu}M) 4.45 Cd or 76.5 Zn, or a metal cocktail containing the same amounts of Cd and Zn along with 7.87 Cu and 24.1 Pb. Plant biomass, metal tolerance and metal accumulation pattern in roots and leaves varied greatly between clones. The leaf:root ratio of metal concentrations was clearly underestimated compared to soil experiments. The largest metal concentrations in leaves were detected in Salix dasyclados (315 mg Cd kg{sup -1} d.m.) and a Salix smithiana clone (3180 mg Zn kg{sup -1} d.m.) but these species showed low metal tolerance. In spite of smaller Cd and Zn concentrations, the metal-tolerant clones Salix matsudana, Salix fragilis-1, and Salix purpurea-1 hold promise for phytoextraction as they produced large biomass and metal contents in leaves. - Hydroponically grown willows and poplar clones accumulate up to (mg kg{sup -1} d.w.) 315 Cd and 3180 Zn in leaves.

Short-rotation cultivation of fast-growing willows and plantations of Betula pendula, Roth on Hirvineva, a mire formerly used for peat production, in Liminka, Finland. Nopeakasvuisten pajujen (Salix spp. ) lyhytkiertoviljelystae ja rauduskoivun (Betula pendula) viljelystae turvetuotannosta poistuneella suolla, limingan Hirvinevalla

Energy Technology Data Exchange (ETDEWEB)

Lumme, I.; Kiukaanniemi, E.

1987-01-01

This report is concerned with afforestation experiments using fast-growing willows (Salix spp.) and silver birch (Betula pendula, Roth) conducted by the Northern Finland Research Institute of the University of Oulu at the site of a mire formerly used for peat production, Hirvineva in the commune of Liminka (62 deg C 45{sup '} N, 23 deg C 30{sup '} E). Experiments were carried out at the early stages of willow cultivation into the use of chemical fertilizers and peat ash, the liming requirement of the soil and the effects of tilling of the soil on growth. Since 1985 efforts have been concentrated on developing new willow clones. Research was also begun into the mycorhiza which develop when willows are cultivated on peat soils. The experiments with Betula pendula were devoted to examining the effects of plantation density and fertilization with peat ash on four-year old saplings.

Establishment and Early Growth of Willow at Different Levels of Weed Competition and Nitrogen Fertilization

DEFF Research Database (Denmark)

Edelfeldt, Stina; Lundkvist, Anneli; Forkman, Johannes

2016-01-01

To evaluate the effects of weed competition and nitrogen fertilization on the early growth performance of willow, cuttings of the clone Tora (Salix schwerinii x S. viminalis) were planted in buckets together with model weeds (spring barley or white mustard) sown 15, 26, and 30 days after willow...... gave higher willow biomass production in willow with weeds sown after 26 or 30 days. Type of model weed had no effect on willow performance. Weed biomass and maximum shoot height were higher in weeds planted without willows compared to the willow-weed mixtures. A high nitrogen level gave more weed...... biomass when planted without willows and in the willow-weed mixture with weeds sown after 15 days. We conclude that for the given high density of willow, competition from weeds emerging soon after willow planting had strong effect on early production. Furthermore, if there is a risk of weed infestation...

Sulfur-aided phytoextraction of Cd and Zn by Salix smithiana combined with in situ metal immobilization by gravel sludge and red mud

International Nuclear Information System (INIS)

Iqbal, Muhammad; Puschenreiter, Markus; Oburger, Eva; Santner, Jakob; Wenzel, Walter W.

2012-01-01

As phytoextraction implementation may be limited by metal toxicity and leaching, we investigated the idea of in situ metal immobilization in bulk soil, while increasing metal bioavailability in the rhizosphere. Salix smithiana was grown in a pot experiment on two Cd/Zn polluted soils. Treatments with or without willows included: no additives; gravel sludge + red mud kg −1 ; acidification with S to pH 3.5; and metal immobilization combined with soil acidification. Salix smithiana removed up to 0.78 ± 0.06% total Cd and 0.34% (±0.02) total Zn from the non-treated soils. The phytoextraction efficiency in the S treatments was enhanced by up to ∼50% in response to metal solubility that was magnified by reductive co-dissolution from Mn (IV) and Fe(III) (oxy)hydroxides during microbial S oxidation in the willow rhizosphere. The proposed technique proved to enhance phytoextraction efficiency while controlling the risk of metal leaching from the root zone and phytotoxicity. - Highlights: ► Phytoextraction of Cd and Zn using willow (Salix smithiana) was enhanced by elemental sulfur. ► Reductive metals dissolution by microbial S oxidation was magnified in the willow rhizosphere. ► Thus metal bioavailability was high at the location of uptake in the phytoextraction crop. ► Concurrent immobilization by soil amendments can reduce metal leaching from the bulk soil. - Magnified Cd and Zn availability in S-amended rhizosphere of Salix smithiana enhances shoot Cd/Zn removal while metal leaching from the root zone can be reduced by immobilizing soil amendments.

Uptake of cadmium from hydroponic solutions by willows ( Salix spp ...

African Journals Online (AJOL)

Salix integra 'Weishanhu') and Yizhibi (S. integra 'Yizhibi') were chosen as model plants to evaluate their potential for uptake of cadmium from hydroponic culture and relative uptake mechanism. Cadmium uptake showed a linear increase in the ...

Significance of stigma receptivity in intergeneric cross-pollination of Salix × Populus

Directory of Open Access Journals (Sweden)

Elżbieta Zenkteler

2016-09-01

Full Text Available The pollen–stigma interaction plays an important role in reproductive process and has been continuously studied in many interspecific and intergeneric crossing experiments. The aim of this study was to investigate stigma receptivity (SR of willow in order to determine the most suitable period for its pollination with poplar pollen and improve the effectiveness of Salix × Populus crosses. Tissue samples were examined histologically using light, epifluorescent, scanning, and transmission electron microscopy. Willow SR was determined by stigma morphological traits, test of pollen germination rate, Peroxtesmo test of peroxidase and esterase activity on stigma surface as well as papilla ultrastructure at anthesis. We have ascertained that the SR duration in willow is short, lasting from 1 to 2 DA. The poplar pollen germination rate on willow stigmas on 1 DA ranged from 26.3 to 11.2%.

Evaluation of the phytoremediation potential of the Salix caprea in tailing ponds

Directory of Open Access Journals (Sweden)

Anca MIHALY-COZMUTA

2009-05-01

Full Text Available The goat willow (Salix caprea belongs to the typical pioneer vegetation at former ore mining sites in East and Middle Europe as a result of its high metal-tolerance. Ectomycorrhizal (EM fungi are known to contribute essentially to the tolerance of plants against abiotic stress. We have determined the absorption/ accretion potential of the goat willow related to heavy metals, as well as the growth rhythm of this species in conditions offered by polluted sites, correlated to the presence/ absence of the microbiota in the soil attached to the root. The research unravels how the goat willow (Salix caprea, as a native species can be used in remediation actions of polluted sites based on its high adaptive potential, as well as on its capacity to absorb and accumulate heavy metals. In terms of survival strategy, mycorhrised fungi attached to the polluted soil play a significant part, since they induce plants a certain resistance by diminishing the absorption of heavy metals by the host plant. We suppose that the majority of EM associations of S. caprea, in combination with high portions of metal-chelating organic acids containing fungal partners, contributes essentially to the high tolerance of this species against high metal concentrations in the soil.

Evaluation of salix farmers experiences and attitudes to growing; Utvaerdering av salixodlares erfarenheter och attityder till odling

Energy Technology Data Exchange (ETDEWEB)

Paulrud, Susanne; Roennbaeck, Marie (Swedish National Testing and Research Inst., Boraas (Sweden)); Gunnarsson, Carina; Olsson, Johanna (Swedish Inst. of Agricultural and Environmental Engineering, Uppsala (Sweden))

2010-11-15

Approximately 16 000 hectares of salix (willow) were planted in Sweden in the early 1990s, driven by subsidies and optimistic market expectations. Today the salix plantations have decreased to approximately 12000 hectares. In this study 29 salix farmers and four entrepreneurs that work with salix harvest were interviewed to find out more about their attitudes to, and experiences of growing salix. Most of the farmers interviewed were not satisfied with their salix plantation. The reasons given were the low profitability and problems with the harvest systems. Key reasons for the low profitability are cited as: old plantations that are planted on poor soil; lack of fertilization; an ineffective organization to taking care of the harvest and to sell the salix chips; and a low price for the salix chips. In addition the system for harvesting needs to be more flexible and there is a need for machine systems adapted for harvest of smaller fields

Pathogenic and Ice-Nucleation Active (INA) Bacteria causing Dieback of Willows in Short Rotation Forestry

Energy Technology Data Exchange (ETDEWEB)

Nejad, Pajand

2005-03-01

To find out whether bacteria isolated from diseased plant parts can be the main causal agent for the dieback appearing in Salix energy forestry plantations in Sweden during the last few years, and if the joint effects of bacteria and frost injury are synergistic, extensive sampling of shoots from diseased Salix plants was performed. We performed several laboratory and greenhouse investigations and used evaluation techniques on the functions of the Ice-Nucleation Active (INA) bacteria. We carried out a comparison between spring and autumn bacterial communities isolated from within (endophytically) and surface (epiphytically) plant tissues of Salix viminalis. Seasonal variation of bacteria in willow clones with different levels of frost sensitivity and symptoms of bacterial damage was also investigated. We further focussed on possible effect of fertilisation and nutrient availability on the bacterial community in relation to plant dieback in Estonian willow plantations. The identification and detection of INA bacteria which cause damage in combination with frost to willow (Salix spp) plants in late fall, winter and spring was performed using BIOLOG MicroPlate, biochemical tests, selective INA primers and 16S rDNA analysis. To distinguish the character for differentiation between these bacteria morphologically and with respect to growing ability different culture media were used. We studied the temperature, at which ice nucleation occurred for individual bacteria, estimated the population of INA bacteria, effect of growth limiting factors, and evaluated the effect of chemical and physical agents for disruption and possible inhibition of INA among individual bacterial strains. The concentration of carbon, nitrogen and phosphorus on INA is discussed. We demonstrate that among the bacterial isolates recovered from the willow plantations, there were many that were capable of ice nucleation at temperatures between -2 and -10 deg C, many that were capable of inducing a

Nutrient Concentrations of Bush Bean (Phaseolus vulgaris L. and Potato (Solanum tuberosum L. Cultivated in Subarctic Soils Managed with Intercropping and Willow (Salix spp. Agroforestry

Directory of Open Access Journals (Sweden)

Meaghan J. Wilton

2017-12-01

Full Text Available To ease food insecurities in northern Canada, some remote communities started gardening initiatives to gain more access to locally grown foods. Bush beans (Phaseolus vulgaris L. and potatoes (Solanum tuberosum L. were assessed for N, P, K, Mg, and Ca concentrations of foliage as indicators of plant nutrition in a calcareous silty loam soil of northern Ontario James Bay lowlands. Crops were grown in sole cropping and intercropping configurations, with comparisons made between an open field and an agroforestry site enclosed with willow (Salix spp. trees. Foliage chemical analysis of the sites revealed an abundance of Ca, adequacies for Mg and N, and deficiencies in P and K. Intercropping bean and potato did not show significant crop–crop facilitation for nutrients. The agroforestry site showed to be a superior management practice for the James Bay lowland region, specifically for P. The agroforestry site had significantly greater P for bean plant (p = 0.024 and potato foliage (p = 0.002 compared to the open site. It is suspected that the presence of willows improve plant available P to bean and potatoes by tree root—crop root interactions and microclimate enhancements.

Evaluating growth effects from an imidacloprid treatment in black willow and eastern cottonwood cuttings

Science.gov (United States)

Luciano de Sene Fernandes; Ray A. Souter; Theodor D. Leininger

2015-01-01

Black willow (Salix nigra Marsh.) and eastern cottonwood (Populus deltoides Bartram ex Marsh.), two species native in the Lower Mississippi Alluvial Valley, have importance in short rotation woody crop (SRWC) systems for biomass production (Ruark 2006).

Feeding preferences of the willow sawfly Nematus oligospilus (Hymenoptera: Tenthredinidae for commercial Salix clones

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Verónica LOETTI

2012-01-01

Full Text Available Nematus oligospilus Förster (Hymenoptera: Tenthredinidae, o la avispa sierra de los sauces, es nativa del Hemisferio Norte y se ha convertido en un serio defoliador en plantaciones de sauces (Salix spp. del Hemisferio Sur, después de su introducción a principios de 1980. Los estudios sobre las preferencias de hospedador aportan información útil para el desarrollo de estrategias, donde la avispa sierra puede producir daño a los árboles y pérdidas económicas. Se evaluó la preferencia alimentaria de las larvas de N. oligospilus, mediante ensayos de laboratorio; se ofrecieron en forma simultánea hojas de cuatro clones de sauce, usados comúnmente en plantaciones comerciales en Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13-44. Las larvas de N. oligospilus se alimentaron de las hojas de los cuatro clones. Sin embargo, consumieron una proporción significativamente mayor de las hojas de S. babylonica var sacramenta. Estos resultados indican que todos los clones utilizados en los ensayos fueron palatables para el insecto y que S. babylonica var sacramenta es el hospedador preferido para la herbivoría de las larvas.

Bottom-up factors influencing riparian willow recovery in Yellowstone National Park

Science.gov (United States)

Tercek, M.T.; Stottlemyer, R.; Renkin, R.

2010-01-01

After the elimination of wolves (Canis lupis L.) in the 1920s, woody riparian plant communities on the northern range of Yellowstone National Park (YNP) declined an estimated 50%. After the reintroduction of wolves in 19951996, riparian willows (Salix spp.) on YNP's northern range showed significant growth for the first time since the 1920s. However, the pace of willow recovery has not been uniform. Some communities have exceeded 400 cm, while others are still at pre-1995 levels of 250 cm max. height) willow sites where willows had escaped elk (Cervus elaphus L.) browsing with "short" willow sites that could still be browsed. Unlike studies that manipulated willow height with fences and artificial dams, we examined sites that had natural growth differences in height since the reintroduction of wolves. Tall willow sites had greater water availability, more-rapid net soil nitrogen mineralization, greater snow depth, lower soil respiration rates, and cooler summer soil temperatures than nearby short willow sites. Most of these differences were measured both in herbaceous areas adjacent to the willow patches and in the willow patches themselves, suggesting that they were not effects of varying willow height recovery but were instead preexisting site differences that may have contributed to increased plant productivity. Our results agree with earlier studies in experimental plots which suggest that the varying pace of willow recovery has been influenced by abiotic limiting factors that interact with top-down reductions in willow browsing by elk. ?? 2010 Western North American Naturalist.

Clonal variation in survival and growth of hybrid poplar and willow in an in situ trial on soils heavily contaminated with petroleum hydrocarbons

Science.gov (United States)

Ronald S., Jr. Zalesny; Edmund O. Bauer; Richard B. Hall; Jill A. Zalesny; Joshua Kunzman; Chris J. Rog; Don E. Riemenschneider

2005-01-01

Species and hybrids between species belonging to the genera Populus (poplar) and Salix (willow) have been used successfully for phytoremediation of contaminated soils. Our objectives were to: 1) evaluate the potential for establishing genotypes of poplar and willow on soils heavily contaminated with petroleum hydrocarbons and 2)...

Phytotoxicity of Sodium Fluoride and Uptake of Fluoride in Willow Trees

DEFF Research Database (Denmark)

Clausen, Lauge Peter Westergaard; Gosewinkel Karlson, Ulrich; Trapp, Stefan

2015-01-01

The willow tree (Salix viminalis) toxicity test and a cress seed germination test (Lepidium sativum) were used to determine uptake and phytotoxicity of NaF. Concentrations in hydroponic solutions were 0-1000 mg F/L and 0-400 mg F/L in the preliminary and definitive test. A third test was done...

Sampling procedure in a willow plantation for chemical elements important for biomass combustion quality

DEFF Research Database (Denmark)

Liu, Na; Nielsen, Henrik Kofoed; Jørgensen, Uffe

2015-01-01

clone ‘Tordis’, and to reveal the relationship between sampling position, shoot diameters, and distribution of elements. Five Tordis willow shoots were cut into 10–50 cm sections from base to top. The ash content and concentration of twelve elements (Al, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Si, and Zn......Willow (Salix spp.) is expected to contribute significantly to the woody bioenergy system in the future, so more information on how to sample the quality of the willow biomass is needed. The objectives of this study were to investigate the spatial variation of elements within shoots of a willow......) in each section were determined. The results showed large spatial variation in the distribution of most elements along the length of the willow shoots. Concentrations of elements in 2-year old shoots of the willow clone Tordis were fairly stable within the range of 100–285 cm above ground and resembled...

Community outreach and education: key components of the Salix consortium's willow biomass project

International Nuclear Information System (INIS)

Volk, T.A.; Edick, S.; Brown, S.; Downing, M.

1999-01-01

This project facilitates the commercialization of willow biomass crops as a locally grown source of renewable energy. The challenge is to simultaneously optimize production and utilization technology, develop farmer interest and crop acreage, and establish stable and reliable markets. The participation of farmers and landowners, businesses, and local and regional governments in the process is essential for success. A three-phased approach elicits this participation: focused outreach and education, active involvement of potential producers of willow biomass crops, and the development of a user-friendly economic and business model that can be used by a variety of stakeholders. Barriers to commercialization have been identified, such as misconceptions about the production system and crop, assurances of a stable and reliable market for the material, and indications that the equipment and infrastructure to grow and process willow biomass crops are in place. Outreach efforts have specifically addressed these issues. As a result target audiences' responses have changed from passive observation to inquiries and suggestions for active participation. This shift represents a significant step towards the goal of making willow biomass crops a viable source of locally produced fuel. (author)

Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia.

Science.gov (United States)

Clausen, Lauge Peter Westergaard; Broholm, Mette Martina; Gosewinkel, Ulrich; Trapp, Stefan

2017-08-01

Trichloroethylene (TCE) is a widespread soil and groundwater pollutant and clean-up is often problematic and expensive. Phytoremediation may be a cost-effective solution at some sites. This study investigates TCE degradation by willows (S. viminalis) and willows inoculated with three strains of B. cepacia (301C, PR1-31 and VM1330-pTOM), using chloride formation as an indicator of dehalogenation. Willows were grown in non-sterile, hydroponic conditions for 3 weeks in chloride-free nutrient solution spiked with TCE. TCE was added weekly due to rapid loss by volatilization. Chloride and TCE in solution were measured every 2-3 days and chloride and metabolite concentrations in plants were measured at test termination. Based on transpiration, no tree toxicity of TCE exposure was observed. However, trees grown in chloride-free solution showed severely inhibited transpiration. No or very little chloride was formed during the test, and levels of chloride in TCE-exposed trees were not elevated. Chloride concentrations in chloride containing TCE-free nutrient solution doubled within 23 days, indicating active exclusion of chloride by root cell membranes. Only traces of TCE-metabolites were detected in plant tissue. We conclude that TCE is not, or to a limited extent (less than 3%), aerobically degraded by the willow trees. The three strains of B. cepacia did not enhance TCE mineralization. Future successful application of rhizo- and phytodegradation of TCE requires measures to be taken to improve the degradation rates.

The potential of willow for remediation of heavy metal polluted calcareous urban soils

International Nuclear Information System (INIS)

Jensen, Julie K.; Holm, Peter E.; Nejrup, Jens; Larsen, Morten B.; Borggaard, Ole K.

2009-01-01

Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium (≥80 mg/kg) and zinc (≥3000 mg/kg) in leaves of willow grown on strongly polluted soil with up to 18 mg Cd/kg, 1400 mg Cu/kg, 500 mg Pb/kg and 3300 mg Zn/kg, it is unsuited on strongly polluted soils because of poor growth. However, willow proved promising on moderately polluted soils (2.5 mg Cd/kg and 400 mg Zn/kg), where it extracted 0.13% of total Cd and 0.29% of the total Zn per year probably representing the most mobile fraction. Cu and Pb are strongly fixed in calcareous soils. - Willow is suited for remediation of moderately heavy metal polluted calcareous soils

Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

International Nuclear Information System (INIS)

Li Jiahua; Sun Yuanyuan; Yin Ying; Ji Rong; Wu Jichun; Wang Xiaorong; Guo Hongyan

2010-01-01

In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L -1 medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L -1 medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d -1 pot -1 for the duration of Day 5-8 and 0.59 mg d -1 pot -1 for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by autochthonous willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River.

Science.gov (United States)

Li, Jiahua; Sun, Yuanyuan; Yin, Ying; Ji, Rong; Wu, Jichun; Wang, Xiaorong; Guo, Hongyan

2010-09-15

In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L(-1) medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L(-1) medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate=68/39 and 53.5/53.5, respectively) reached 0.71 mg d(-1) pot(-1) for the duration of Day 5-8 and 0.59 mg d(-1) pot(-1) for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River. Copyright 2010 Elsevier B.V. All rights

Removal of 4-chlorobenzoic acid from spiked hydroponic solution by willow trees (Salix viminalis)

DEFF Research Database (Denmark)

Deavers, K.; Macek, T.; Karlson, U.

2010-01-01

. Methods The removal of 4-CBA by willow trees was investigated with intact, septic willow trees growing in hydroponic solution and with sterile cell suspensions at concentrations of 5 mg/L and 50 mg/L 4-CBA. Nutrient solutions with different levels of ammonium and nitrate were prepared to achieve different...

Competition favors elk over beaver in a riparian willow ecosystem

Science.gov (United States)

Baker, B.W.; Peinetti, H.R.; Coughenour, M.C.; Johnson, T.L.

2012-01-01

Beaver (Castor spp.) conservation requires an understanding of their complex interactions with competing herbivores. Simulation modeling offers a controlled environment to examine long-term dynamics in ecosystems driven by uncontrollable variables. We used a new version of the SAVANNA ecosystem model to investigate beaver (C. Canadensis) and elk (Cervus elapses) competition for willow (Salix spp.). We initialized the model with field data from Rocky Mountain National Park, Colorado, USA, to simulate a 4-ha riparian ecosystem containing beaver, elk, and willow. We found beaver persisted indefinitely when elk density was or = 30 elk km_2. The loss of tall willow preceded rapid beaver declines, thus willow condition may predict beaver population trajectory in natural environments. Beaver were able to persist with slightly higher elk densities if beaver alternated their use of foraging sites in a rest-rotation pattern rather than maintained continuous use. Thus, we found asymmetrical competition for willow strongly favored elk over beaver in a simulated montane ecosystem. Finally, we discuss application of the SAVANNA model and mechanisms of competition relative to beaver persistence as metapopulations, ecological resistance and alternative state models, and ecosystem regulation.

The role and significance of Salix plantations for energy in Swedish agriculture

Energy Technology Data Exchange (ETDEWEB)

Forsse, L.S.; Ledin, S.; Johansson, H. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

1993-12-31

Fifteen years of research and development of energy forestry with Salix species has lead to a firm basis of knowledge concerning the basic biology, stand ecology and production systems of fast growing willows in Sweden. The biology research program continues to emphasize studies of plant biology and diseases as well as areas such as clone/site interactions, mixed clonal plantations and breeding. The technological research and development concentrates on functional and effective machinery for planting, harvesting, etc. Recently Salix plantations for energy production in Sweden have been commercialized. Plantations start with 18,000 cuttings of willow clones per hectare. During the first summer weed control is the most important treatment. Fertilizers are applied to keep a high production level. Crops are harvested during winter at 3--5 year intervals. The average annual production is about 10--12 tonnes DM per hectare. The life of Salix plantations is estimated as 25--30 years. An estimated potential of 300,000 hectares of Salix plantations would result 5% of the energy needs in Sweden. Wood fuel from the conventional forest equals 60 TWh today, with a potential of being doubled within 10--20 years. The economic outcome for the farmer of growing Salix mainly depends on the price of chips and the level of production. A fundamental requirement for establishing plantations is that there is a wood fuel market within a reasonable distance (about 50 km). In a calculation stretching over a period of 24 years with a production level of 12 tonnes DM per hectare and year, and at an interest rate of 6%, the net return is about 1,000--1,500 SEK/ha/yr (about 7 SEK/US$) if simultaneous chipping is used. With separate harvest and chipping and enterprise in this calculation breaks even. Interest in the utilization of sludge, ash, waste water and leakage water as nutrients for energy forests is increasing from local and regional authorities.

Effect of temperature on the uptake and metabolism of cyanide by weeping willows

DEFF Research Database (Denmark)

Yu, X.-Z.; Trapp, Stefan; Zhou, P.-H.

2007-01-01

Plants’ uptake and metabolism of cyanide in response to changes in temperature was investigated. Pre-rooted weeping willows (Salix babylonica L.) were exposed to hydroponic solution spiked with potassium cyanide for 2–3 d. Ten different temperatures were used, ranging from 11◦C to 32◦C. Cyanide...

Phytotoxicity of polycyclic aromatic hydrocarbons to willow trees

Energy Technology Data Exchange (ETDEWEB)

Thygesen, R.S.; Trapp, S. [Environment and Resources DTU, Technical Univ. of Denmark, Lyngby (Denmark)

2002-07-01

The toxicity of PAH to willow trees (Salix alba, S. viminalis, S. viminalis x schwerinii) was investigated. Willow cuttings were grown in PAH-saturated hydroponic solution (naphthalene NAP, phenanthrene PHEN and benzo(a)pyrene BaP). Toxicity was related to aqueous solubility and was highest for NAP. PHEN did not show significant effects, except in one case. Exposure of trees to BaP showed no effect in two cases, but increased transpiration and growth in two others. High dosages of NAP were fatal for the trees, the lowest dosage significantly stimulated growth. Soil samples were taken from several PAH contaminated sites, among them gas works sites and a former sludge basin. The PAH contents ranged from 1.76 mg/kg to 1451 mg/kg. None of the soils was lethally toxic to the trees, and difference between growth in control soils and growth in PAH contaminated soils was not apparent. Growth and water use efficiency were positively, but not significantly correlated to the PAH content of the soils. Outdoor growth of willows and poplars on the former sludge basin in Valby was monitored, with willows growing faster than poplars (Populus trichocarpa). Phytotoxic effects could be observed at some willows at the Valby sludge basin, but it is not sure whether these effects can be contributed to PAH. (orig.)

Treatment of log yard run-off by irrigation of grass and willows

International Nuclear Information System (INIS)

Jonsson, Maria; Dimitriou, Ioannis; Aronsson, Paer; Elowson, Torbjoern

2006-01-01

Log yard run-off is a potential environmental risk, among other things because it creates an oxygen deficiency in receiving watercourses. This study was conducted to investigate the purification efficiency of soil-plant systems with couchgrass (Elymus repens) and willows (Salix sp.) when intensively irrigated with run-off from an open sprinkling system at a Norway spruce (Picea abies) log yard. The purification efficiency was determined both at the field scale (couchgrass) and in 68-L lysimeters (couchgrass and willows). Groundwater in the field and drainage water from the lysimeters were analysed for Total Organic Carbon (TOC), distillable phenols, total P, and total N. Retention of TOC, phenols and P occurred but no difference between couchgrass and willows was observed. The system had better purification capacity at the field scale than in the lysimeters. -- By irrigating willow and couchgrass soil-plant systems with log yard run-off water, TOC, phenols, and phosphorus were reduced with 35% to 96% in the water

Phytoremediation prospects of willow stands on contaminated sediment: a field trial

International Nuclear Information System (INIS)

Vervaeke, P.; Luyssaert, S.; Mertens, J.; Meers, E.; Tack, F.M.G.; Lust, N.

2003-01-01

A field trial indicated increased degradation of mineral oil in sediments planted with willow. - Establishing fast growing willow stands on land disposed contaminated dredged sediment can result in the revaluation of this material and opens possibilities for phytoremediation. A field trial was designed to assess the impact of planting a willow stand (Salix viminalis L. 'Orm') on the dissipation of organic contaminants (mineral oil and PAHs) in dredged sediment. In addition, the accumulation of heavy metals (Cd, Cu, Pb and Zn) in the biomass was determined. After 1.5 years, a significant decrease of 57% in the mineral oil concentration in the sediment planted with willow was observed. Degradation of mineral oil in sediment which was left fallow, was only 15%. The mineral oil degradation under willow was most pronounced (79%) in the root zone of the stand. In the sediment which was left fallow there was a significant reduction of the total PAH content by 32% compared with a 23% reduction in the planted sediment. The moderate and selective metal uptake, measured in this study, limits the prospects for phytoextraction of metals from dredged sediment

Phytoremediation prospects of willow stands on contaminated sediment: a field trial

Energy Technology Data Exchange (ETDEWEB)

Vervaeke, P.; Luyssaert, S.; Mertens, J.; Meers, E.; Tack, F.M.G.; Lust, N

2003-11-01

A field trial indicated increased degradation of mineral oil in sediments planted with willow. - Establishing fast growing willow stands on land disposed contaminated dredged sediment can result in the revaluation of this material and opens possibilities for phytoremediation. A field trial was designed to assess the impact of planting a willow stand (Salix viminalis L. 'Orm') on the dissipation of organic contaminants (mineral oil and PAHs) in dredged sediment. In addition, the accumulation of heavy metals (Cd, Cu, Pb and Zn) in the biomass was determined. After 1.5 years, a significant decrease of 57% in the mineral oil concentration in the sediment planted with willow was observed. Degradation of mineral oil in sediment which was left fallow, was only 15%. The mineral oil degradation under willow was most pronounced (79%) in the root zone of the stand. In the sediment which was left fallow there was a significant reduction of the total PAH content by 32% compared with a 23% reduction in the planted sediment. The moderate and selective metal uptake, measured in this study, limits the prospects for phytoextraction of metals from dredged sediment.

The Willow Microbiome is Influenced by Soil Petroleum-Hydrocarbon Concentration with Plant Compartment-Specific Effects

Directory of Open Access Journals (Sweden)

Stacie Tardif

2016-09-01

Full Text Available The interaction between plants and microorganisms, which is the driving force behind the decontamination of petroleum hydrocarbon (PHC contamination in phytoremediation technology, is poorly understood. Here, we aimed at characterizing the variations between plant compartments in the microbiome of two willow cultivars growing in contaminated soils. A field experiment was set-up at a former petrochemical plant in Canada and, after two growing seasons, bulk soil, rhizosphere soil, roots and stems samples of two willow cultivars (Salix purpurea cv. FishCreek and Salix miyabeana cv. SX67 growing at three PHC contamination concentrations were taken. DNA was extracted and bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS regions were amplified and sequenced using an Ion Torrent Personal Genome Machine. Following multivariate statistical analyses, the level of PHC-contamination appeared as the primary factor influencing the willow microbiome with compartment-specific effects, with significant differences between the responses of bacterial and fungal communities. Increasing PHC contamination levels resulted in shifts in the microbiome composition, favoring putative hydrocarbon degraders and microorganisms previously reported as associated with plant health. These shifts were less drastic in the rhizosphere, root and stem tissues as compared to bulk soil, probably because the willows provided a more controlled environment and thus protected microbial communities against increasing contamination levels. Insights from this study will help to devise optimal plant microbiomes for increasing the efficiency of phytoremediation technology.

Concentrations of Chemical Elements in Willow Biomass Depend on Clone, Site and Management in the Field

DEFF Research Database (Denmark)

Liu, Na; Jørgensen, Uffe; Lærke, Poul Erik

2016-01-01

Eight willow (Salix) clones (Inger, Klara, Linnea, Resolution, Stina, Terra Nova, Tora, Tordis) were planted on two soil types in Denmark. The biomass quality was evaluated after 3 years of growth by measuring differences in concentrations of 14 elements associated with ash behavior during combus...

Ethyl lactate-EDTA composite system enhances the remediation of the cadmium-contaminated soil by Autochthonous Willow (Salix x aureo-pendula CL 'J1011') in the lower reaches of the Yangtze River

Energy Technology Data Exchange (ETDEWEB)

Li Jiahua [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Sun Yuanyuan [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Yin Ying; Ji Rong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Wu Jichun [State Key Laboratory of Pollution Control and Resource Reuse, Department of Hydrosciences, Nanjing University, Nanjing 210093 (China); Wang Xiaorong [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Guo Hongyan, E-mail: hyguo@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

2010-09-15

In order to explore a practical approach to the remediation of the cadmium (Cd)-contaminated soil in the lower reaches of the Yangtze River, we evaluated the effects of a local willow (Salix x aureo-pendula CL 'J1011') of absorbing, accumulating, and translocating Cd; and assessed the potential of chelator ethylenediaminetetraacetic acid (EDTA) in combination with ethyl lactate for enhancing the efficiency of the willow in removing Cd in two water-culture growth chamber trials and a field one. The willow showed a high tolerance to Cd in growth chamber trial 1 where the Cd concentration in the medium reached up to 25 mg L{sup -1} medium, and the bioaccumulation factors (BAFs) of the shoots for Cd rose from 3.8 to 7.4 as the Cd concentration in the medium was elevated from 5 to 25 mg L{sup -1} medium. In growth chamber trial 2, the average Cd removal rates in two treatments with EDTA and ethyl lactate (molar ratios of EDTA to ethyl lactate = 68/39 and 53.5/53.5, respectively) reached 0.71 mg d{sup -1}pot{sup -1} for the duration of Day 5-8 and 0.59 mg d{sup -1}pot{sup -1} for that of Day 8-11, which were 5- and 4-fold of their counterparts in the control, respectively. In the field trial, for the remediational duration of 45 days, three treatments-willow alone, willow combined with EDTA, and willow combined with EDTA and ethyl lactate-led to decreases in the Cd concentration in soil by 5%, 20%, and 29%, respectively; increases in that in the leaves by 14.6%, 56.7%, and 146.5%, respectively; and increases in that in the stems by 15.6%, 41.2%, and 87.4%, respectively, compared to their counterparts on Day 0. These results indicate that EDTA combined with ethyl lactate significantly enhanced the efficiency of willow in removing Cd from the soil. Therefore, a phytoextration system consisting of the autochthonous willow, EDTA, and ethyl lactate has high potential for the remediation of the Cd-polluted soil in the lower reaches of the Yangtze River.

Can energy willow (Salix sp.) remediate cadmium- and nickel-contaminated fish farm sludge?

DEFF Research Database (Denmark)

Pedersen, Marianne Bruus

it meets the criteria. Phytoremediation by willow may combine accumulation of cadmium and nickel from the sludge with the production of an energy crop. The ability of eight selected willow clones to take up and tolerate cadmium and nickel was studied in pots under outdoor conditions. Fish farm sludge...

Willow vegetation filters: Principles, results and economy

International Nuclear Information System (INIS)

Perttu, K.

1996-01-01

During recent years, it has become obvious that it is both environmentally and economically appropriate to use vegetation filters of different short rotation willows (Salix spp.) to purify water and soil. Swedish experiences of vegetation filter efficiencies have been demonstrated in several laboratory, field lysimeter, and full-scale experiments. However, there are still many questions to be answered, for example, how the uptake and allocation mechanisms of heavy metals and recalcitrant organic constituents function, or which maximum doses are possible in a particular situation without any risk of leachate losses. As far as plant nutrition is concerned, the past two decades of integrated research in Sweden have demonstrated that the willows have capacity for efficient uptake both of macro and micro nutrients, which is reflected in their high productivity. The purpose of this paper is to present some results on how vegetation filter stands of willow, irrigated with municipal wastewater, can function as purification plants, while at the same time producing fuelwood. This twofold utilization benefits both the environment and the economy. Treatment plants for wastewater purification using various types of vegetation filters have been tried in Sweden. The experiences consider both the nutrient and heavy metal uptake, and the whole process chain from establishment, cultivation and harvesting of the wastewater irrigated willow stands, to the utilization of the wood in heating plants. 33 refs, 5 tabs

Assessment of Salix spp. pollen availability to insects based on aerobiological investigations

Directory of Open Access Journals (Sweden)

Elżbieta Weryszko-Chmielewska

2017-06-01

Full Text Available Pollen and nectar produced by flowers of species from the genus Salix are an important source of food for various insect groups in early spring. Most willows are entomophilous species; however, substantial amounts of airborne Salix pollen can be noted. The aim of the study was to evaluate the content of pollen of this taxon in the air of Lublin (central-east Poland in 2001–2016 and to identify the period of its greatest availability to insects. In 2015, we compared the course of the Salix pollen season in Lublin (51°14'37" N; 22°32'25" E and in the Roztoczański National Park (50°34'57" N; 23°04'24" E, Poland. We found that the date of the pollen season onset fluctuated greatly between March 16 and April 17. The greatest availability of Salix pollen to insects was noted from the end of the first 10-day-period of April to the first 10-day-period of May. The mean annual sum of airborne Salix pollen grains was 833. In Lublin, Salix pollen accounted for ca. 1.25% of the total airborne pollen content of different plant taxa. The investigations have demonstrated a 2-year cycle of Salix pollen abundance. The comparison of the pollen seasons in Lublin and in the Roztoczański National Park indicates that considerably greater amounts of pollen occur in the urban area than in the air of the Roztoczański National Park.

Growth of Populus and Salix Species under Compost Leachate Irrigation

Directory of Open Access Journals (Sweden)

Tooba Abedi

2014-12-01

Full Text Available According to the known broad variation in remediation capacity, three plant species were used in the experiment: two fast growing poplar’s clones - Populus deltoides, Populus euramericana, and willows Salix alba. Populus and Salix cuttings were collected from the nursery of the Populus Research Center of Safrabasteh in the eastern part of Guilan province at north of Iran. The Populus clones were chosen because of their high biomass production capacity and willow- because it is native in Iran. The highest diameter growth rate was exhibited for all three plant species by the 1:1 treatment with an average of 0.26, 0.22 and 0.16 cm in eight months period for P. euroamericana, P. deltoides and S. alba, respectively. Over a period of eight months a higher growth rate of height was observed in (P and (1:1 treatment for S. alba (33.70 and 15.77 cm, respectively and in (C treatment for P. deltoides (16.51 cm. P. deltoides and S. alba produced significantly (p<0.05 smaller aboveground biomass in (P treatment compared to all species. P. deltoides exhibited greater mean aboveground biomass in the (1:1 treatment compared to other species. There were significant differences (p<0.05 in the growth of roots between P. deltoides, P. euramericana and S. alba in all of the treatments.

Characterising willows for biomass and phytoremediation: growth, nitrogen and water use of 14 willow clones under different irrigation and fertilisation regimes

International Nuclear Information System (INIS)

Weih, Martin; Nordh, N.-E.

2002-01-01

Fourteen clones of willow (Salix spp.) were characterised in terms of growth, nitrogen and water-use efficiency under different irrigation and fertilisation treatments. Cuttings of willow clones, some commercially introduced and others new material, were pot-grown outdoors in Central Sweden under four experimental treatments in a full-factorial design. The experiment covered the period from bud-break until leaf abscission and the experimental conditions included two irrigation and two fertilisation regimes. The growth of the clones was evaluated in terms of relative growth rate and total biomass production of whole plants and shoots. Nitrogen (N) economy was studied by means of N productivity, N accumulation and N losses by leaf abscission. Water economy was analysed with respect to intrinsic water-use efficiency (foliar carbon isotope ratio; δ 13 C) and the capacity of leaves to retain water (relative water content). Significant differences between clones were found in nearly all parameters measured and the clones varied in the responses to the experimental treatments (clone x factor interaction effects). Thus, clone ranking often changed depending on the experimental treatment. The results are discussed with respect to clone selection for different willow applications such as biomass production and phytoremediation, and willow growth performance under different water and nutrient availabilities. The growth-physiological characterisation of young willows in the short term (several months) is regarded as a suitable approach for pre-selection of promising clones prior to extensive field evaluation

Treatment of landfill leachate by irrigation of willow coppice - Plant response and treatment efficiency

International Nuclear Information System (INIS)

Aronsson, Paer; Dahlin, Torleif; Dimitriou, Ioannis

2010-01-01

Landfill leachates usually need to be treated before discharged, and using soil-plant systems for this has gained substantial interest in Sweden and in the UK. A three-year field study was conducted in central Sweden to quantify plant response, treatment efficiency and impact on groundwater quality of landfill leachate irrigation of short-rotation willow coppice (Salix). Two willow varieties were tested and four irrigation regimes in sixteen 400-m 2 plots. The willow plants did not react negatively, despite very high annual loads of nitrogen (≤2160 kg N/ha), chloride (≤8600 kg Cl/ha) and other elements. Mean annual growth was 1.5, 9.8 and 12.6 tonnes DM/ha during years 1-3. For one of two willow varieties tested, relative leaf length accurately predicted growth rate. Irrigation resulted in elevated groundwater concentrations of all elements applied. Treatment efficiency varied considerably for different elements, but was adequate when moderate loads were applied. - Short-rotation willow coppice was successfully used for treating a strong landfill leachate in central Sweden over three years.

Comparison of willow and sunflower for uranium phytoextraction induced by citric acid

International Nuclear Information System (INIS)

Jan Mihalik; National Radiation Protection Institute, Prague; CZU, FAPPZ, Prague; Pavel Tlustos; Jirina Szakova

2010-01-01

This study deals with an efficiency of a low dose of citric acid soil application on phytoextraction of uranium. Willow (Salix spp.) and sunflower (Helianthus annus L.) were tested in this experiment with contaminated soil. The enhancing of uranium bioaccumulation was confirmed, but in contrast to previous studies, the highest quantity of uranium was accumulated in leaves. After 5 weeks of citric acid treatment, willow was more efficient in the uptake and translocation of uranium than sunflower. The transfer coefficient calculated for leaves increased from 0.033 (control) to 0.74, or 0.56 after five doses of 5 mmol of citric acid per 1 kg of soil for willow or sunflower, respectively. The uptake characterized by the total U content achieved 88 and 108 mg kg -1 in relation to the above ground parts of sunflower and willow, respectively. Even though both plants accumulated U in their above ground parts in significant rate, they employed diverse ways to achieve it. At the end of the treatment, the physiological condition of the plants enabled us to continue this method. (author)

Water tables constrain height recovery of willow on Yellowstone's northern range.

Science.gov (United States)

Bilyeu, Danielle M; Cooper, David J; Hobbs, N Thompson

2008-01-01

Excessive levels of herbivory may disturb ecosystems in ways that persist even when herbivory is moderated. These persistent changes may complicate efforts to restore ecosystems affected by herbivores. Willow (Salix spp.) communities within the northern range in Yellowstone National Park have been eliminated or degraded in many riparian areas by excessive elk (Cervus elaphus L.) browsing. Elk browsing of riparian willows appears to have diminished following the reintroduction of wolves (Canis lupis L.), but it remains uncertain whether reduced herbivory will restore willow communities. The direct effects of elk browsing on willows have been accompanied by indirect effects from the loss of beaver (Castor canadensis Kuhl) activity, including incision of stream channels, erosion of fine sediments, and lower water tables near streams historically dammed by beaver. In areas where these changes have occurred, lowered water tables may suppress willow height even in the absence of elk browsing. We conducted a factorial field experiment to understand willow responses to browsing and to height of water tables. After four years of protection from elk browsing, willows with ambient water tables averaged only 106 cm in height, with negligible height gain in two of three study species during the last year of the experiment. Willows that were protected from browsing and had artificially elevated water tables averaged 147 cm in height and gained 19 cm in the last year of the experiment. In browsed plots, elevated water tables doubled height gain during a period of slightly reduced browsing pressure. We conclude that water availability mediates the rate of willow height gain and may determine whether willows grow tall enough to escape the browse zone of elk and gain resistance to future elk browsing. Consequently, in areas where long-term beaver absence has resulted in incised stream channels and low water tables, a reduction in elk browsing alone may not be sufficient for recovery

Development of an applied black willow tree improvement program for biomass production in the south

Science.gov (United States)

Randall J. Rousseau; Emile S. Gardiner; Theodor D. Leininger

2012-01-01

The development of rapidly growing biomass woody crops is imperative as the United States strives to meet renewable energy goals. The Department of Energy has indicated that biomass is a prime source for renewable energy for the southern United States. Black Willow (Salix nigra Marsh.) is a potential bioenergy/biofuels crop for dedicated short-...

In vitro regeneration of Salix nigra from adventitious shoots.

Science.gov (United States)

Lyyra, Satu; Lima, Amparo; Merkle, Scott A

2006-07-01

Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation.

Use of willows in evapotranspirative systems for onsite wastewater management – theory and experiences from Denmark

DEFF Research Database (Denmark)

Brix, Hans; Arias, Carlos Alberto

2011-01-01

aspects of ET systems is their ability to evapotranspire all of the sewage discharged into the systems and the rain falling onto the systems. On an annual basis the ET should equal the amount of wastewater discharged into the system plus the amount of precipitation falling onto the system. Part...... with clones of willow (Salix viminalis L.). The surface area of the systems depends on the amount and quality of the sewage to be treated and the local annual rainfall. A single household in Denmark typically requires between 120 and 300 m2. The annual precipitation at the site of construction is an important...... dimensioning parameter. Settled sewage is dispersed underground into the bed under pressure. The stems of the willows are harvested on a regular basis to stimulate the growth of the willows and to remove some nutrients and heavy metals. In this paper, the theory behind the operation of willow based ET systems...

Test of aerobic TCE degradation by willows (Salix viminalis) and willows inoculated with TCE-cometabolizing strains of Burkholderia cepacia

DEFF Research Database (Denmark)

Clausen, Lauge Peter Westergaard; Broholm, Mette Martina; Gosewinkel, Ulrich Bay

2017-01-01

. cepacia (301C, PR1-31 and VM1330-pTOM), using chloride formation as an indicator of dehalogenation. Willows were grown in non-sterile, hydroponic conditions for 3 weeks in chloride-free nutrient solution spiked with TCE. TCE was added weekly due to rapid loss by volatilization. Chloride and TCE...

Wolf presence and increased willow consumption by Yellowstone elk: implications for trophic cascades.

Science.gov (United States)

Creel, Scott; Christianson, David

2009-09-01

Recent increases in the height and growth ring width of willow (Salix spp.) and other woody plants in the Greater Yellowstone Ecosystem (GYE) have been attributed to a behaviorally mediated trophic cascade from wolves (Canis lupus) to elk (Cervus elaphus) to willows. This hypothesis predicts that individual elk consume less willow in response to the presence of wolves, but this prediction has not been directly tested with data from elk. We collected 727 fecal samples from elk in the Gallatin Canyon portion of the GYE over three winters and used microhistological methods to quantify the proportion of willow in each sample. We then tested the effect of wolf presence on willow consumption by elk, controlling for the effects of snow conditions, sex, and habitat type. During the period of study, 8-17 wolves occupied the study area, and wolves were locally present on 49% of 260 sampling days, stratified at two-week intervals across three drainages. Over the three years combined, willow consumption was related to snow conditions, wolf presence, and a wolf X sex interaction. As expected, willow consumption increased with deeper and less penetrable snow, and this effect was strong. Contrary to expectation, willow consumption increased in the presence of wolves. As with other aspects of antipredator behavior, wolves had different effects on willow consumption by males and females. Finally, we aggregated the data to estimate winter-long mean willow consumption within each drainage; at this broader scale, willow consumption again increased as predation risk increased. In summary, willow consumption was more strongly affected by snow conditions than by the presence of wolves. Interactions between elk and willow were affected by wolves, but not as predicted by the hypothesis that wolf presence favors willow release through a reduction in the selection of willow by individual elk. If a trophic cascade is operating, our results suggest that a decline in the size of the elk

Willow yield is highly dependent on clone and site

DEFF Research Database (Denmark)

Ugilt Larsen, Søren; Jørgensen, Uffe; Lærke, Poul Erik

2014-01-01

Use of high-yielding genotypes is one of the means to achieve high yield and profitability in willow (Salix spp.) short rotation coppice. This study investigated the performance of eight willow clones (Inger, Klara, Linnea, Resolution, Stina, Terra Nova, Tora, Tordis) on five Danish sites......, differing considerably in soil type, climatic conditions and management. Compared to the best clone, the yield was up to 36 % lower for other clones across sites and up to 51 % lower within sites. Tordis was superior to other clones with dry matter yields between 5.2 and 10.2 Mg ha−1 year−1 during the first...... 3-year harvest rotation, and it consistently ranked as the highest yielding clone on four of the five sites and not significantly lower than the highest yielding clone on the fifth site. The ranking of the other clones was more dependent on site with significant interaction between clone and site...

Water relations and gas exchange in poplar and willow under water stress and elevated atmospheric CO2.

Science.gov (United States)

Johnson, Jon D; Tognetti, Roberto; Paris, Piero

2002-05-01

Predictions of shifts in rainfall patterns as atmospheric [CO2] increases could impact the growth of fast growing trees such as Populus spp. and Salix spp. and the interaction between elevated CO2 and water stress in these species is unknown. The objectives of this study were to characterize the responses to elevated CO2 and water stress in these two species, and to determine if elevated CO2 mitigated drought stress effects. Gas exchange, water potential components, whole plant transpiration and growth response to soil drying and recovery were assessed in hybrid poplar (clone 53-246) and willow (Salix sagitta) rooted cuttings growing in either ambient (350 &mgr;mol mol-1) or elevated (700 &mgr;mol mol-1) atmospheric CO2 concentration ([CO2]). Predawn water potential decreased with increasing water stress while midday water potentials remained unchanged (isohydric response). Turgor potentials at both predawn and midday increased in elevated [CO2], indicative of osmotic adjustment. Gas exchange was reduced by water stress while elevated [CO2] increased photosynthetic rates, reduced leaf conductance and nearly doubled instantaneous transpiration efficiency in both species. Dark respiration decreased in elevated [CO2] and water stress reduced Rd in the trees growing in ambient [CO2]. Willow had 56% lower whole plant hydraulic conductivity than poplar, and showed a 14% increase in elevated [CO2] while poplar was unresponsive. The physiological responses exhibited by poplar and willow to elevated [CO2] and water stress, singly, suggest that these species respond like other tree species. The interaction of [CO2] and water stress suggests that elevated [CO2] did mitigate the effects of water stress in willow, but not in poplar.

Railway transport and terminal transhipment of Short Rotation Willow Crops. Pre-study; Taagtransport och terminal-hantering av Salix. Foerstudie

Energy Technology Data Exchange (ETDEWEB)

Forsberg, Maya

2009-07-01

The overall aim of this pre-study is to contribute to an increased co-handling of biomass from forest and field at terminal and railway transport, in order to find effective transport solutions with regard to costs and environment. The aim of the pre-study is also to get an overall picture of transport of biomass on railway. The objective is to draw conclusions of use for interested parties within the agricultural sector, on what possibilities there are to handle biomass from forestry and agriculture with the same logistical infrastructure. Conclusions are drawn especially with regard to Short Rotation Willow Crops (here Salix) handled as chips or bundles, but also briefly for other energy crops suitable for combustion. Furthermore, the study draws conclusions on how to design effective terminals and related costs. The pre-study is intended as a planning material for a more in-depth study of a mobile terminal solution, with active participation from interested players in the agricultural sector. When considering railway transport and terminal transhipment of large volumes of biomass, there is a clear economical benefit in designing large terminals and making investments in effective handling equipment, in order to get a high use of equipment and a high storage turnover. A more simple and temporary terminal solution may be suitable for smaller flows of biomass, such as agricultural fuels, which need to be collected in different areas according to availability. An intermodal solution, i.e. which involves the transportation of freight in the same type of carrier (a container for example) when changing modes of transportation, is suitable for this purpose. The solution should also build on standardised equipment, involve low terminal investments and flexible and temporary transhipment in different areas near the location of the biomass. For railway transport, the same handling equipment may be used for wood chips and Salix chips, i.e. standardised container systems

Willow clones with high biomass yield in short rotation coppice in the southern region of Tohoku district (Japan)

International Nuclear Information System (INIS)

Mitsui, Yu; Seto, Shoko; Nishio, Mari; Minato, Kazuya; Ishizawa, Kimiharu; Satoh, Shigeru

2010-01-01

The present study was conducted to select willow (Salix spp.) clones with a high potential for use as biomass energy crops in the southern region of Tohoku district in Japan. Cuttings of 8 willow clones were planted on an abandoned farmland near Sendai (av. annual temp., 10.9 o C) in March 2006, grown throughout the year and cut back in late December 2006 to resprout from the remaining stools in March 2007. The biomass yield in December 2007, after the first growing season, was highest in Salix pet-susu clone KKD, followed by Salix pseudolinearis clone FXM and Salix sachalinensis clone SEN. The biomass yield on December 2008, after the second growing season, was again highest in clone KKD followed by clone FXM, S. pet-susu clone HB471 and S. sachalinensis clone SEN; the average annual yield of dry mass after the second growing season being 3.09, 2.58, 2.17 and 1.85 kgDM plant -1 for the clones in this order. Plant growth form differed among the clones. Clones FXM and SEN had several shoots of almost uniform base diameter, whereas clones KKD and HB471 showed plagiotropic growth with one thick and several thin shoots. The calorific values of dried stem segments were similar among clones, ranging from 18.7 to 19.1 kJ g -1 . The dried stem segments contained 78.9-81.2 wt.% hollocellulose, 27.2-32.3 wt.% lignin and 2.1-4.0 wt.% extractives with ethanol-benzene, depending on clones. Based on these results, we could select four clones (KKD, FXM, HB471 and SEN) suitable for biomass production by SRWC in this area.

The effect of pH on the uptake and toxicity of the bivalent weak base chloroquine tested on Salix viminalis and Daphnia magna

DEFF Research Database (Denmark)

Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan

2011-01-01

, and therefore a higher toxicity can be expected. The current study examines the pHdependent toxicity and bioaccumulation of the bivalent weak base chloroquine (pKa: 10.47 and 6.33, log KOW 4.67) tested on Salix viminalis (basket willow) and Daphnia magna (water flea). The transpiration rates of hydroponically...

Screening of willow species for resistance to heavy metals: comparison of performance in a hydroponics system and field trials.

Science.gov (United States)

Watson, C; Pulford, I D; Riddell-Black, D

2003-01-01

The aim of this study was to ascertain whether metal resistance in willow (Salix) clones grown in a hydroponics screening test correlated with data from the same clones grown independently in a field trial. If so, results from a short-term, glasshouse-based system could be extrapolated to the field, allowing rapid identification of willows suitable for planting in metal-contaminated substrates without necessitating longterm field trials. Principal Components Analysis was used to show groups of clones and to assess the relative importance of the parameters measured in both the hydroponics system and the field; including plant response factors such as increase in stem height, as well as metal concentrations in plant tissues. The clones tested fell into two distinct groups. Salix viminalis clones and the basket willow Black Maul (S. triandra) were less resistant to elevated concentrations of heavy metals than a group of hardier clones, including S. burjatica 'Germany,' S.x dasyclados, S. candida and S. spaethii. The more resistant clones produced more biomass in the glasshouse and field, and had higher metal concentrations in the wood. The less resistant clones had greater concentrations of Cu and Ni in the bark, and produced less biomass in the glasshouse and field. Significant relationships were found between the response of the same clones grown the in short-term glasshouse hydroponics system and in the field.

A comparison of the suitability of different willow varieties to treat on-site wastewater effluent in an Irish climate.

Science.gov (United States)

Curneen, S J; Gill, L W

2014-01-15

Short rotation coppiced willow trees can be used to treat on-site wastewater effluent with the advantage that, if planted in a sealed basin and sized correctly, they produce no effluent discharge. This paper has investigated the evapotranspiration rate of four different willow varieties while also monitoring the effects of three different effluent types on each variety. The willow varieties used are all cultivars of Salix viminalis. The effluents applied were primary (septic tank) effluent, secondary treated effluent and rain water (control). The results obtained showed that the addition of effluent had a positive effect on the evapotranspiration. The willows were also found to uptake a high proportion of the nitrogen and phosphorus from the primary and secondary treated effluents added during the first year. The effect of the different effluents on the evapotranspiration rate has been used to design ten full scale on-site treatment systems which are now being monitored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Variation in copper and zinc tolerance and accumulation in 12 willow clones: implications for phytoextraction*

Science.gov (United States)

Yang, Wei-dong; Wang, Yu-yan; Zhao, Feng-liang; Ding, Zhe-li; Zhang, Xin-cheng; Zhu, Zhi-qiang; Yang, Xiao-e

2014-01-01

Willows (Salix spp.) have shown high potential for the phytoextraction of heavy metals. This study compares variations in copper (Cu) and zinc (Zn) tolerance and accumulation potential among 12 willow clones grown in a nutrient solution treated with 50 μmol/L of Cu or Zn, respectively. The results showed differences in the tolerance and accumulation of Cu and Zn with respect to different species/clones. The biomass variation among clones in response to Cu or Zn exposure ranged from the stimulation of growth to inhibition, and all of the clones tested showed higher tolerance to Cu than to Zn. The clones exhibited less variation in Cu accumulation but larger variation in Zn accumulation. Based on translocation factors, it was found that most of the Cu was retained in the roots and that Zn was more mobile than Cu for all clones. It is concluded that most willow clones are good accumulators of Zn and Cu. PMID:25183033

Uptake, accumulation and metabolic response of ferricyanide in weeping willows.

Science.gov (United States)

Yu, Xiao-Zhang; Gu, Ji-Dong

2009-01-01

The remediation potential and metabolic responses of plants to ferricyanide were investigated using pre-rooted weeping willows (Salix babylonica L.) grown hydroponically in growth chambers and treated with potassium ferricyanide. Positive responses were observed for the plants exposed to cyanide recovered in plant biomass was constant in all treatments, indicating that transport is a major limiting step for the uptake of ferricyanide by plants. The majority of the ferricyanide taken up from the growth media was possibly assimilated during transport through plants. The velocity of the removal processes can be described by Michaelis-Menten kinetics, and the half-saturation constant (K(M)) and the maximum removal capacity (v(max)) were estimated to be 228.1 mg CN L(-1) and 36.43 mg CN kg(-1) d(-1), respectively, using non-linear regression methods. These results suggest that weeping willows can take up, transport and assimilate ferricyanide; and phytoremediation is an option for cleaning up the environmental sites contaminated with cyanide complexes.

Willow on Yellowstone's northern range: evidence for a trophic cascade?

Science.gov (United States)

Beyer, Hawthorne L; Merrill, Evelyn H; Varley, Nathan; Boyce, Mark S

2007-09-01

Reintroduction of wolves (Canis lupus) to Yellowstone National Park in 1995-1996 has been argued to promote a trophic cascade by altering elk (Cervus elaphus) density, habitat-selection patterns, and behavior that, in turn, could lead to changes within the plant communities used by elk. We sampled two species of willow (Salix boothii and S. geyeriana) on the northern winter range to determine whether (1) there was quantitative evidence of increased willow growth following wolf reintroduction, (2) browsing by elk affected willow growth, and (3) any increase in growth observed was greater than that expected by climatic and hydrological factors alone, thereby indicating a trophic cascade caused by wolves. Using stem sectioning techniques to quantify historical growth patterns we found an approximately twofold increase in stem growth-ring area following wolf reintroduction for both species of willow. This increase could not be explained by climate and hydrological factors alone; the presence of wolves on the landscape was a significant predictor of stem growth above and beyond these abiotic factors. Growth-ring area was positively correlated with the previous year's ring area and negatively correlated with the percentage of twigs browsed from the stem during the winter preceding growth, indicating that elk browse impeded stem growth. Our results are consistent with the hypothesis of a behaviorally mediated trophic cascade on Yellowstone's northern winter range following wolf reintroduction. We suggest that the community-altering effects of wolf restoration are an endorsement of ecological-process management in Yellowstone National Park.

Irrigation water quality influences heavy metal uptake by willows in biosolids.

Science.gov (United States)

Laidlaw, W Scott; Baker, Alan J M; Gregory, David; Arndt, Stefan K

2015-05-15

Phytoextraction is an effective method to remediate heavy metal contaminated landscapes but is often applied for single metal contaminants. Plants used for phytoextraction may not always be able to grow in drier environments without irrigation. This study investigated if willows (Salix x reichardtii A. Kerner) can be used for phytoextraction of multiple metals in biosolids, an end-product of the wastewater treatment process, and if irrigation with reclaimed and freshwater influences the extraction process. A plantation of willows was established directly onto a tilled stockpile of metal-contaminated biosolids and irrigated with slightly saline reclaimed water (EC ∼2 dS/cm) at a wastewater processing plant in Victoria, Australia. Biomass was harvested annually and analysed for heavy metal content. Phytoextraction of cadmium, copper, nickel and zinc was benchmarked against freshwater irrigated willows. The minimum irrigation rate of 700 mm per growing season was sufficient for willows to grow and extract metals. Increasing irrigation rates produced no differences in total biomass and also no differences in the extraction of heavy metals. The reclaimed water reduced both the salinity and the acidity of the biosolids significantly within the first 12 months after irrigation commenced and after three seasons the salinity of the biosolids had dropped to metal extraction. Reclaimed water irrigation reduced the biosolid pH and this was associated with reductions of the extraction of Ni and Zn, it did not influence the extraction of Cu and enhanced the phytoextraction of Cd, which was probably related to the high chloride content of the reclaimed water. Our results demonstrate that flood-irrigation with reclaimed water was a successful treatment to grow willows in a dry climate. However, the reclaimed water can also change biosolids properties, which will influence the effectiveness of willows to extract different metals. Copyright © 2015 Elsevier Ltd. All rights

Harvest and logistics for better profitability from small cultivations of Short Rotation Willow Coppice; Skoerdeteknik och logistik foer baettre loensamhet fraan smaa odlingar av Salix

Energy Technology Data Exchange (ETDEWEB)

Baky, Andras; Forsberg, Maya; Rosenqvist, Haakan; Jonsson, Nils; Sundberg, Martin

2010-06-15

In Sweden, the political desire to increase the amount of short rotation willow coppice (Salix) plantations has been expressed. However, for various reasons interest from farmers has been low. The hypothesis of this study is that the total area of Salix cultivation can be increased by also cultivating fields smaller than those generally considered economic today. In order to lower production costs, machine systems adapted for harvest of smaller fields are required. The possibility of using farmers' existing tractors and more convenient machines, as well as achieving lower machine costs for smaller fields, may increase farmers' interest. The long-term objective is to achieve large-scale deliveries of willow with small-scale solutions at farm level, as an option and complement to today's more large-scale systems for harvesting willow. Costs, energy use and climatic impact (CO{sub 2} emissions) for two harvest and logistical chains suitable for small fields have been calculated from field to energy plant, and methods for minimizing these costs have been analyzed. Comparison is made with the direct chipping system, the most commonly used in Sweden today. The systems studied comprised: 1. Direct bundling harvest system with a tractor-towed harvester, collection of bundles in the field with a trailer-mounted crane, and storage in a pile before delivery. Chipping is performed at the energy plant. 2. Direct billeting with a tractor-towed harvester accompanied simultaneously by a tractor and trailer for collection, and storage in a pile before delivery. 3. Direct chipping with a self-propelled modified forage harvester accompanied simultaneously by a tractor and container for collection, and direct delivery to plant. Both the billet and bundle systems show higher costs than the direct chipping system, irrespective of field size. The analysis of different scenarios and conditions shows possibilities of lowering the costs through certain measures. Furthermore

Environmental effects of energy forest (short rotation willow)

International Nuclear Information System (INIS)

Frank, K.

1994-01-01

This paper deals with environmental effects of producing and combusting energy forest fuel. Energy forest means short rotation willow (Salix). Supposed effects of sewage sludge application are discussed as well. Energy forestry on agricultural land implies both advantages and disadvantages for the environment. Leaf litter (humified leaves) increases the humus content in the top soil. The soil fauna is also positively affected. Until now performed studies about nitrogen leakage from fields cultivated with energy forest (Salix), have not given any distinct results. A retarded drainage within energy forest fields is on the other hand noticed. While the root system of Salix is active during a long period of the year, the nitrogen leakage become less compared to traditional cultivation. The content of plant nutrients and organic matter in sewage sludge make a resource that can be useful for agricultural purposes, especially for energy forest cultivation. The content of heavy metals and organic emissions contradicts sludge application to agricultural land. Sewage sludge with todays quality increases somewhat the content of heavy metals in the soil. This condition can be counteracted to a certain extent by growing energy forest. It has been established that Salix has high ability to heavy metal uptake, especially cadmium. Growing energy forest on drained farm land is connected with a risk for root penetration into the drainage system. With enough water and plant nutrients in the top soil the risk is reduced. Shallow depth of the pipes increases the risk. Combustion of wood chip from energy forests (and other types of biomass) gives especially two advantages. It does not give any net contribution of carbon dioxide to the atmosphere. The sulphur discharge will be minimal since the sulphur content in wood fuels is low. Discharge of nitrogen oxide and hydrocarbons may give some problems. These can be reduced by technological measures when combusting. 27 refs, 4 tabs

Phytoremediation capacity of poplar (Populus spp. and willow (Salix spp. clonesin relation to photosynthesis

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Pajević Slobodanka

2009-01-01

Full Text Available Good photosynthetic features and a favorable water regimes of woody plants improve their survival and remediation potential under unfavorable ecological conditions. Accordingly, we here present results of testing plant tolerance of Pb, Cd, Ni, and diesel fuel based on gas exchange parameters and WUE of four poplar and two willow clones grown in a greenhouse on soil culture. Photosynthesis and transpiration of plants grown on soils with individually applied heavy metals decreased significantly, but this was less obvious in the case of Cd treatment. A heavy metal mixture in the soil induced significant reduction in photosynthesis (by more than 50%. Diesel fuel as the only pollutant in soil caused very strong and significant inhibition of photosynthesis and transpiration of willow clones. The results indicate genotypic specificity of all investigated physiological parameters and mark poplar clones as very useful in phytoextraction technology for the bio-cleaning of chemically polluted soils.

Wastewater purification in a willow plantation. The case study at Aarike

International Nuclear Information System (INIS)

Kuusemets, V.; Mauring, T.

1996-01-01

In order to combine wastewater purification and biomass production for energy purposes, a willow plantation for wastewater treatment was established in 1995 in Aarike, Southern Estonia. Wastewater from a dwelling house (25 person equivalents, pe) is treated in a combined free-water filter system consisting of three separate basins, isolated with clay and having filter beds of gravel and sand mixture. The beds were planted with Salix viminalis. At the end of the first growing season, the purification efficiency of the newly established treatment system was 65% for BOD 7 , 43% for nitrogen and 11% for phosphorus removal. At the end of the establishment year, the above ground production of willow stems (bark and wood) and leaves was 1.3 and 0.3 t ha -1 , respectively. The figures are about three to five times higher than those recorded in previously established energy forest plantations of comparable ages in Estonia. 15 refs, 2 figs

UTILIZATION OF ANIMAL MEAL FOR GROWING OF WILLOW DEDICATED FOR ENERGY

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Anna Nogalska

2016-09-01

Full Text Available The aim of the study was to evaluate the effects of increased rates of meat and bone meal (MBM to the soil on biomass yield, nitrogen (N and phosphorus (P content, and their accumulation in above ground biomass Salix viminalis, as well as the content of mineral N and available P forms in the soil. A two-year pot experiment was conducted at Warmia and Mazury University in Olsztyn (north-eastern Poland. Average biomass yield from two seasons of the studies was three higher from MBM treatments comparing to unfertilized control. Higher rates of MBM particularly in the second year showed higher yielding potential compared with mineral fertilizers. Willow biomass harvested from MBM treatments generally showed lower content of studied nutrients than willow from control treatment. It was found that in relation to the control accumulation of N in willow above ground biomass was significantly lower for 0.5% MBM treatment and significantly higher for the treatment with the highest rate (2.0%. The higher accumulation of P was found in the second year after MBM application, except treatment with the lowest MBM rate. Correlation coefficients values indicated that there is a relation between MBM rate and content of mineral N and available P in soil.

Cytospora species from Populus and Salix in China with C. davidiana sp. nov.

Science.gov (United States)

Wang, Yan-Li; Lu, Quan; Decock, Cony; Li, Yong-Xia; Zhang, Xing-Yao

2015-05-01

Poplar and willow plantations have become widespread in China, in order to meet national economic and environmental needs. The emergence of several pathogens is enhanced by climatic change and associated human factors. Species of Cytospora are well-known pathogens on poplar and willow, and cause stem cankers and diebacks. In the present study, we conducted a survey of Cytospora species occurring on Populus spp. and Salix spp. in China. We used morphological examination and phylogenetic inferences, based on the DNA sequence data from the internal transcribed spacer regions (ITS1, 5.8S rDNA, and ITS2) and partial β-tubulin gene, to identify six Cytospora species occurring on poplar and willow. Five of these species belonged to known taxa, viz. Cytospora chrysosperma (asexual state of Valsa sordida), Cytospora translucens (asexual state of Leucostoma translucens), Cytospora fugax (asexual state of Valsa salicina), Cytospora atrocirrhata, and Cytospora kantschavelii. Our study yielded a new species, Cytospora davidiana sp. nov., on poplar. The new species is characterized by typical torsellioid conidiomata. An additional Cytospora sp. 1, which formed a distinct clade in the phylogenetic inferences, remains unnamed; the paucity of available materials prevented phenotypical characterization. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

The development of short-rotation willow in the northeastern United States for bioenergy and bioproducts, agroforestry and phytoremediation

International Nuclear Information System (INIS)

Volk, T.A.; Abrahamson, L.P.; Nowak, C.A.; White, E.H.; Smart, L.B.; Tharakan, P.J.

2006-01-01

Research on willow (Salix spp.) as a locally produced, renewable feedstock for bioenergy and bioproducts began in New York in the mid-1980s in response to growing concerns about environmental impacts associated with fossil fuels and declining rural economies. Simultaneous and integrated activities-including research, large-scale demonstrations, outreach and education, and market development-were initiated in the mid-1990s to facilitate the commercialization of willow biomass crops. Despite technological viability and associated environmental and local economic benefits, the high price of willow biomass relative to coal has been a barrier to wide-scale deployment of this system. The cost of willow biomass is currently $3.00GJ -1 ($57.30odt -1 ) compared to $1.40-1.90GJ -1 for coal. Yield improvements from traditional breeding efforts and increases in harvesting efficiency that are currently being realized promise to reduce the price differential. Recent policy changes at the federal level, including the provision to harvest bioenergy crops from Conservation Reserve Program (CRP) land and a closed-loop biomass tax credit, and state-level initiatives such as Renewable Portfolio Standards (RPS) will help to further reduce the difference and foster markets for willow biomass. Years of work on willow biomass crop research and demonstration projects have increased our understanding of the biology, ecophysiology and management of willow biomass crops. Using an adaptive management model, this information has led to the deployment of willow for other applications such as phytoremediation, living snow fences, and riparian buffers across the northeastern US. (author)

Production capacity of biomass of the floodpain community of Salix alba L. in southern Moravia

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Diana López

2007-01-01

Full Text Available The paper deals with the study of the production capacity of biomass in the seven-year stand of Salix alba L. The communities originated in the process of primary succession in the area of the middle Nové Mlýny reservoir on a newly established island. Already since the first stages, the communities have been monitored. Results have shown that white willow behaves as an R-strategist with fast growth in youth. Moreover, the growth is supported by optimum environmental conditions (soils richly supplied with nutrients and water, long growing season. Accumulated phytomass amounted 102,7 t.ha−1 at the age of 7 years and the yield reached a mean annual increment of 15 t.ha−1.year−1. Communities of white willow rank among highly productive phytocoenoses capable of fixing considerable amounts of carbon and, at the same time fulfilling the function of habitat corridors.

Simulation modeling to understand how selective foraging by beaver can drive the structure and function of a willow community

Science.gov (United States)

Peinetti, H.R.; Baker, B.W.; Coughenour, M.B.

2009-01-01

Beaver-willow (Castor-Salix) communities are a unique and vital component of healthy wetlands throughout the Holarctic region. Beaver selectively forage willow to provide fresh food, stored winter food, and construction material. The effects of this complex foraging behavior on the structure and function of willow communities is poorly understood. Simulation modeling may help ecologists understand these complex interactions. In this study, a modified version of the SAVANNA ecosystem model was developed to better understand how beaver foraging affects the structure and function of a willow community in a simulated riparian ecosystem in Rocky Mountain National Park, Colorado (RMNP). The model represents willow in terms of plant and stem dynamics and beaver foraging in terms of the quantity and quality of stems cut to meet the energetic and life history requirements of beaver. Given a site where all stems were equally available, the model suggested a simulated beaver family of 2 adults, 2 yearlings, and 2 kits required a minimum of 4 ha of willow (containing about10 stems m-2) to persist in a steady-state condition. Beaver created a willow community where the annual net primary productivity (ANPP) was 2 times higher and plant architecture was more diverse than the willow community without beaver. Beaver foraging created a plant architecture dominated by medium size willow plants, which likely explains how beaver can increase ANPP. Long-term simulations suggested that woody biomass stabilized at similar values even though availability differed greatly at initial condition. Simulations also suggested that willow ANPP increased across a range of beaver densities until beaver became food limited. Thus, selective foraging by beaver increased productivity, decreased biomass, and increased structural heterogeneity in a simulated willow community.

Phytoremediation of Metal Contaminated Soil Using Willow: Exploiting Plant-Associated Bacteria to Improve Biomass Production and Metal Uptake.

Science.gov (United States)

Janssen, Jolien; Weyens, Nele; Croes, Sarah; Beckers, Bram; Meiresonne, Linda; Van Peteghem, Pierre; Carleer, Robert; Vangronsveld, Jaco

2015-01-01

Short rotation coppice (SRC) of willow and poplar is proposed for economic valorization and concurrently as remediation strategy for metal contaminated land in northeast-Belgium. However, metal phytoextraction appears insufficient to effectuate rapid reduction of soil metal contents. To increase both biomass production and metal accumulation of SRC, two strategies are proposed: (i) in situ selection of the best performing clones and (ii) bioaugmentation of these clones with beneficial plant-associated bacteria. Based on field data, two experimental willow clones, a Salix viminalis and a Salix alba x alba clone, were selected. Compared to the best performing commercial clones, considerable increases in stem metal extraction were achieved (up to 74% for Cd and 91% for Zn). From the selected clones, plant-associated bacteria were isolated and identified. All strains were subsequently screened for their plant growth-promoting and metal uptake enhancing traits. Five strains were selected for a greenhouse inoculation experiment with the selected clones planted in Cd-Zn-Pb contaminated soil. Extraction potential tended to increase after inoculation of S. viminalis plants with a Rahnella sp. strain due to a significantly increased twig biomass. However, although bacterial strains showing beneficial traits in vitro were used for inoculation, increments in extraction potential were not always observed.

Resprout and survival of willows (Salix purpurea and S. incana), Poplars (Populus nigra) and Tamaris (Tamarix gallica) cuttings in marly gullies with Southern aspect in a mountainous and Mediterranean climate (Southern Alps, France)

Science.gov (United States)

Rey, Freddy; Labonne, Sophie; Dangla, Laure; Lavandier, Géraud

2014-05-01

In the Southern French Alps under a mountainous and Mediterranean climate, a current strategy of bioengineering is developed for trapping sediment in marly gullies with surface area less than 1 ha. It is based on the use of structures in the form of brush layers and brush mats of cuttings on deadwood microdams. Purple and white Willows (Salix purpurea and S. incana) are recommended here as they proved their efficiency to resprout and survive in such environment. However, these species installed in Southern gullies did not survive in previous experiments, due to the too harsh conditions of solar radiation and drought. We thus decided to test other species, namely black Poplar (Populus nigra) and Tamaris (Tamarix gallica), which proved their resistance to drought conditions in other experiments. To this view, bioengineering structures have been built in 2010 in eroded marly gullies in the Roubines and Fontaugier catchments (Southern Alps, France). We tested two installation modalities: one in spring and a second in autumn. Seventy-eight bioengineering structures (50 in spring and 28 in autumn), among which 32 made with Poplar cuttings and 28 with Tamaris cuttings, as well as 11 structures with purple Willow and 7 with white Willow as controls, were built in 6 experimental gullies. After 3 observation years for each modality (2010 to 2012, and 2011 to 2013, respectively), results first revealed that Willow species succeeded in surviving in gullies in Southern aspect (76 % for the cuttings installed in spring and 52 % for those installed in autumn), which is in contradiction with previous results. Second, Poplar showed a good ability to survive (62 % for the cuttings installed in spring and 33 % for those installed in autumn). Tamaris obtained the worst score with 26 % and 38 % of survival for the cuttings installed in spring and autumn, respectively. Globally, excepted for Tamaris, survival rates were better for the cuttings installed in spring. The bioengineering

COMPACTION STUDIES OF TORREFIED WILLOW

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Michał Rejdak

2017-01-01

Full Text Available The article presents the results of studies of torrefied willow (Salix viminalis L. compaction. Densification tests were performed using a hydraulic press with a maximum pressure of 216 MPa. The effect of basic parameters of the briquetting process (pressure and temperature on mechanical parameters of manufactured briquettes were determined. On the basis of the research, it was found that the increase in pressure and temperature of the densification process increases the density and strength of pressed briquettes. The positive effect of temperature is particularly noticeable at lower pressing pressures (36 MPa – 72 MPa. In the case of a temperature of 300 °C, the increase in a pressure from 144 MPa to 216 MPa resulted in the decrease in the density and strength of the briquette. It was also found that the briquettes manufactured at this temperature are characterized by lower density and strength than the briquettes obtained at a temperature of 200 °C.

Variations in metal tolerance and accumulation in three hydroponically cultivated varieties of Salix integra treated with lead.

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Shufeng Wang

Full Text Available Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou, a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production, but a low translocation factor (TF, indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests.

Variations in Metal Tolerance and Accumulation in Three Hydroponically Cultivated Varieties of Salix integra Treated with Lead

Science.gov (United States)

Sun, Haijing; Chen, Yitai; Pan, Hongwei; Yang, Xiaoe; Rafiq, Tariq

2014-01-01

Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb) tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou), a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI) and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production), but a low translocation factor (TF), indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests. PMID:25268840

Wastewater sludge fertilization: Biomass productivity and heavy metal bioaccumulation in two Salix species grown in southern Quebec (Canada)

International Nuclear Information System (INIS)

Teodorescu, T.I.; Labrecque, M.; Daigle, S.; Poisson, G.

1993-01-01

More than other kind of trees, fast growing tree species, such as willows, can profit from sludge application. While sludges are good fertilizers, they may also contain heavy metals which could reduce productivity and cause risks to the environment. The main aims of the present research were to study: (1) the production capacity of Salix discolor and Salix viminalis when supplied with various amounts of dried and pelleted sludge; (2) the uptake, and accumulation of heavy metals. Unrooted cuttings were planted on sandy soil in large plastic pots and grown in outdoors for 20-week period. Five doses of sludge were applied: equivalent of 200 (T1), 160 (T2), 120 (T3), 80 (T4) and 40 (T5) kg N per ha. Trees which received the largest amount of sludge showed the best growth results. The stem-branch biomass was significantly higher for Salix viminalis. The relationship between the total yield biomass Y (t/ha) and the rate of fertilization X (kg N/ha) is linear. The regression equations of prediction biomass production were established as following: Salix discolor Y = 1.807 + 0.037X and Salix viminalis Y = 2.578 + 0.042X. For both species, greatest stems-branch biomass per gram of N applied were produced by treatments 1 and 2. The amount of nitrogen per leaf area (N/LA) and per leaf dry weight (N/LW), were higher for Salix viminalis which leads us believe that its photosynthetic activity was better. The transfer coefficient did not vary between the species but was significantly different for Cd and Zn. The plants were able to absorb Cd and Zn but less of Ni, Hg and Cu and Pb. It was concluded that the dried and pelleted sludge can be a good fertilizer. The treatment is beneficial when Salix discolor and particulary Salix viminalis are used as vegetation filters for wastewater sludge purification and production purposes

Assembly and comparative analysis of complete mitochondrial genome sequence of an economic plant Salix suchowensis

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Ning Ye

2017-03-01

Full Text Available Willow is a widely used dioecious woody plant of Salicaceae family in China. Due to their high biomass yields, willows are promising sources for bioenergy crops. In this study, we assembled the complete mitochondrial (mt genome sequence of S. suchowensis with the length of 644,437 bp using Roche-454 GS FLX Titanium sequencing technologies. Base composition of the S. suchowensis mt genome is A (27.43%, T (27.59%, C (22.34%, and G (22.64%, which shows a prevalent GC content with that of other angiosperms. This long circular mt genome encodes 58 unique genes (32 protein-coding genes, 23 tRNA genes and 3 rRNA genes, and 9 of the 32 protein-coding genes contain 17 introns. Through the phylogenetic analysis of 35 species based on 23 protein-coding genes, it is supported that Salix as a sister to Populus. With the detailed phylogenetic information and the identification of phylogenetic position, some ribosomal protein genes and succinate dehydrogenase genes are found usually lost during evolution. As a native shrub willow species, this worthwhile research of S. suchowensis mt genome will provide more desirable information for better understanding the genomic breeding and missing pieces of sex determination evolution in the future.

Genome-wide identification and characterization of WRKY gene family in Salix suchowensis.

Science.gov (United States)

Bi, Changwei; Xu, Yiqing; Ye, Qiaolin; Yin, Tongming; Ye, Ning

2016-01-01

WRKY proteins are the zinc finger transcription factors that were first identified in plants. They can specifically interact with the W-box, which can be found in the promoter region of a large number of plant target genes, to regulate the expressions of downstream target genes. They also participate in diverse physiological and growing processes in plants. Prior to this study, a plenty of WRKY genes have been identified and characterized in herbaceous species, but there is no large-scale study of WRKY genes in willow. With the whole genome sequencing of Salix suchowensis, we have the opportunity to conduct the genome-wide research for willow WRKY gene family. In this study, we identified 85 WRKY genes in the willow genome and renamed them from SsWRKY1 to SsWRKY85 on the basis of their specific distributions on chromosomes. Due to their diverse structural features, the 85 willow WRKY genes could be further classified into three main groups (group I-III), with five subgroups (IIa-IIe) in group II. With the multiple sequence alignment and the manual search, we found three variations of the WRKYGQK heptapeptide: WRKYGRK, WKKYGQK and WRKYGKK, and four variations of the normal zinc finger motif, which might execute some new biological functions. In addition, the SsWRKY genes from the same subgroup share the similar exon-intron structures and conserved motif domains. Further studies of SsWRKY genes revealed that segmental duplication events (SDs) played a more prominent role in the expansion of SsWRKY genes. Distinct expression profiles of SsWRKY genes with RNA sequencing data revealed that diverse expression patterns among five tissues, including tender roots, young leaves, vegetative buds, non-lignified stems and barks. With the analyses of WRKY gene family in willow, it is not only beneficial to complete the functional and annotation information of WRKY genes family in woody plants, but also provide important references to investigate the expansion and evolution of

Physiological and morphological responses of pine and willow saplings to post-fire salvage logging

Science.gov (United States)

Millions, E. L.; Letts, M. G.; Harvey, T.; Rood, S. B.

2015-12-01

With global warming, forest fires may be increasing in frequency, and post-fire salvage logging may become more common. The ecophysiological impacts of this practice on tree saplings remain poorly understood. In this study, we examined the physiological and morphological impacts of increased light intensity, due to post-fire salvage logging, on the conifer Pinus contorta (pine) and deciduous broadleaf Salix lucida (willow) tree and shrub species in the Crowsnest Pass region of southern Alberta. Photosynthetic gas-exchange and plant morphological measurements were taken throughout the summer of 2013 on approximately ten year-old saplings of both species. Neither species exhibited photoinhibition, but different strategies were observed to acclimate to increased light availability. Willow saplings were able to slightly elevate their light-saturated rate of net photosynthesis (Amax) when exposed to higher photosynthetic photon flux density (PPFD), thus increasing their growth rate. Willow also exhibited increased leaf inclination angles and leaf mass per unit area (LMA), to decrease light interception in the salvage-logged plot. By contrast, pine, which exhibited lower Amax and transpiration (E), but higher water-use efficiency (WUE = Amax/E) than willow, increased the rate at which electrons were moved through and away from the photosynthetic apparatus in order to avoid photoinhibition. Acclimation indices were higher in willow saplings, consistent with the hypothesis that species with short-lived foliage exhibit greater acclimation. LMA was higher in pine saplings growing in the logged plot, but whole-plant and branch-level morphological acclimation was limited and more consistent with a response to decreased competition in the logged plot, which had much lower stand density.

Differential effects of glyphosate and aminomethylphosphonic acid (AMPA) on photosynthesis and chlorophyll metabolism in willow plants.

Science.gov (United States)

Gomes, Marcelo Pedrosa; Le Manac'h, Sarah Gingras; Maccario, Sophie; Labrecque, Michel; Lucotte, Marc; Juneau, Philippe

2016-06-01

We used a willow species (Salix miyabeana cultivar SX64) to examine the differential secondary-effects of glyphosate and aminomethylphosphonic acid (AMPA), the principal glyphosate by-product, on chlorophyll metabolism and photosynthesis. Willow plants were treated with different concentrations of glyphosate (equivalent to 0, 1.4, 2.1 and 2.8kgha(-1)) and AMPA (equivalent to 0, 0.28, 1.4 and 2.8kgha(-1)) and evaluations of pigment contents, chlorophyll fluorescence, and oxidative stress markers (hydrogen peroxide content and antioxidant enzyme activities) in leaves were performed after 12h of exposure. We observed that AMPA and glyphosate trigger different mechanisms leading to decreases in chlorophyll content and photosynthesis rates in willow plants. Both chemicals induced ROS accumulation in willow leaves although only glyphosate-induced oxidative damage through lipid peroxidation. By disturbing chlorophyll biosynthesis, AMPA induced decreases in chlorophyll contents, with consequent effects on photosynthesis. With glyphosate, ROS increases were higher than the ROS-sensitive threshold, provoking chlorophyll degradation (as seen by pheophytin accumulation) and invariable decreases in photosynthesis. Peroxide accumulation in both AMPA and glyphosate-treated plants was due to the inhibition of antioxidant enzyme activities. The different effects of glyphosate on chlorophyll contents and photosynthesis as described in the literature may be due to various glyphosate:AMPA ratios in those plants. Copyright © 2015 Elsevier Inc. All rights reserved.

Cadmium in willow plantations - municipal waste products as fertilizers

International Nuclear Information System (INIS)

Hasselgren, K.

1995-07-01

Plantations of willows (i.e. Salix spp) seem to absorb cadmium (Cd) from arable land to a greater extent than other plant cultivations. Thus, energy forestry, based upon cultivation of Salix, could possibly be used for biofuel production in combination with biological purification of arable land contaminated with Cd by atmospheric deposition and P fertilizers during the passed 100 years. Application of sewage sludge (5-7 ppm Cd of dry solids) up to 550 g Cd per hectare, or 140 g Cd hectare and year, resulted in clearly increased concentrations of Cd in the upper 10 cm layer of the soil. In deeper soil layers the differences compared with control plots were small. Lower rates of sludge application, corresponding to less than 70 g added per hectare and year, did not materially affect the Cd-content in the soil irrespective of layer. A general pattern was that the content of Cd in plant tissues decreased with increased stem diameter, increased age of stems and stands as well as increased biomass growth. Thus, concentrations of Cd in Salix material, in clones from some of the first generation of energy forest plants (S. viminalis, S. dasyclados and S. schwerinii). were fairly high in young stands. In general, 1-year-old shoots contained 5-6 ppm Cd of dry solids in stems and 10-15 ppm in leaves. In older shoots, up to three years, and older stands, up to six years, the Cd contents decreased to 1-2 ppm Cd and 2-4 ppm Cd of dry solids for stems and leaves, respectively. Abundant supplies of water and nutrients seem to stimulate the Cd uptake in Salix in terms of higher concentrations in plant tissues as well as higher plant growth levels compared with conventional energy forestry. Stands with older stems, not irrigated and not fully fertilized resulted in uptake rates in the range of 10-30 g Cd per hectare and year. 14 refs, 9 figs, 1 tab

Influence of flooding and metal immobilising soil amendments on availability of metals for willows and earthworms in calcareous dredged sediment-derived soils

Energy Technology Data Exchange (ETDEWEB)

Vandecasteele, Bart, E-mail: bart.vandecasteele@ilvo.vlaanderen.b [Institute for Agricultural and Fisheries Research (ILVO), Scientific Institute of the Flemish Government, Burg. Van Gansberghelaan 109, B-9820 Merelbeke (Belgium); Du Laing, Gijs [Ghent University, Department of Applied Analytical and Physical Chemistry, Coupure 653, B-9000 Ghent (Belgium); Lettens, Suzanna [Research Institute for Nature and Forest (INBO), Scientific Institute of the Flemish Government, Gaverstraat 4, B-9500 Geraardsbergen (Belgium); Jordaens, Kurt [Department of Biology, Evolutionary Biology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Tack, Filip M.G. [Ghent University, Department of Applied Analytical and Physical Chemistry, Coupure 653, B-9000 Ghent (Belgium)

2010-06-15

Soil amendments previously shown to be effective in reducing metal bioavailability and/or mobility in calcareous metal-polluted soils were tested on a calcareous dredged sediment-derived soil with 26 mg Cd/kg dry soil, 2200 mg Cr/kg dry soil, 220 mg Pb/kg dry soil, and 3000 mg Zn/kg dry soil. The amendments were 5% modified aluminosilicate (AS), 10% w/w lignin, 1% w/w diammonium phosphate (DAP, (NH{sub 4}){sub 2}HPO{sub 4}), 1% w/w MnO, and 5% w/w CaSO{sub 4}. In an additional treatment, the contaminated soil was submerged. Endpoints were metal uptake in Salix cinerea and Lumbricus terrestris, and effect on oxidation-reduction potential (ORP) in submerged soils. Results illustrated that the selected soil amendments were not effective in reducing ecological risk to vegetation or soil inhabiting invertebrates, as metal uptake in willows and earthworms did not significantly decrease following their application. Flooding the polluted soil resulted in metal uptake in S. cinerea comparable with concentrations for an uncontaminated soil. - Some soil amendments resulted in higher metal uptake by earthworms and willows than when the polluted soil was not amended but submersion of the polluted soil resulted in reduced Cd and Zn uptake in Salix cinerea.

Yield Mapping in Salix; Skoerdekartering av salix

Energy Technology Data Exchange (ETDEWEB)

Anderson, Christoffer; Gilbertsson, Mikael; Rogstrand, Gustav; Thylen, Lars

2004-09-01

The most common species for energy forest production is willow. Willow is able to produce a large amount of biomass in a short period of time. Growing willow has a potential to render a good financial result for the farmer if cultivated on fields with the right conditions and plenty of water. Under the right conditions growing willow can give the farmer a net income of 3,000 SEK (about 430 USD) per hectare and year, which is something that common cereal crops cannot compete with. However, this is not the common case since willow is often grown as a substitute crop on fields where cereal crop yield is low. The aim of this study was to reveal if it is possible to measure yield variability in willow, and if it is possible to describe the reasons for yield variation both within the field but also between different fields. Yield mapping has been used in conventional farming for about a decade. The principles for yield mapping are to continuously measure the yield while registering location by the use of GPS when harvesting the field. The collected data is then used to search for spatial variations within the field, and to try to understand the reasons for this variation. Since there is currently no commercial equipment for yield mapping in willow, a yield mapping system had to be developed within this project. The new system was installed on a Claas Jaguar harvester. The principle for yield mapping on the Claas Jaguar harvester is to measure the distance between the feeding rollers. This distance is correlated to the flow through the harvester. The speed and position of the machine was registered using GPS. Knowing the working width of the harvester this information was used to calculate the yield. All collected data was stored on a PDA computer. Soil samples were also collected from the yield mapped fields. This was to be able to test yield against both physical and chemical soil parameters. The result shows that it is possible to measure spatial variations of yield in

The neutral species of the weak base trimethoprim is more toxic to willow trees (Salix viminalis) than the cation

DEFF Research Database (Denmark)

Mikes, O.; Trapp, Stefan

2011-01-01

The acute toxicity of the veterinary antibiotic trimethoprim (TMP) to willow trees was tested at three different pH levels in hydroponic solutions with TMP concentrations of 1, 10, 100 or 1000 mg/L. The pH variation was achieved by using ammonium (pH 4.3, low) or nitrate (pH 6.4, medium) as nitro......The acute toxicity of the veterinary antibiotic trimethoprim (TMP) to willow trees was tested at three different pH levels in hydroponic solutions with TMP concentrations of 1, 10, 100 or 1000 mg/L. The pH variation was achieved by using ammonium (pH 4.3, low) or nitrate (pH 6.4, medium...

Can liming change root anatomy, biomass allocation and trace element distribution among plant parts of Salix × smithiana in trace element-polluted soils?

Science.gov (United States)

Vondráčková, Stanislava; Tlustoš, Pavel; Száková, Jiřina

2017-08-01

Willows (Salix spp.) are considered to be effective for the phytoremediation of trace elements from contaminated soils, but their efficiency is limited in heavily polluted soils because of poor growth. Liming can be a desirable measure to decrease the plant availability of elements, resulting in improved plant development. Notably, large root area and maximum soil penetration are basic parameters that improve the efficiency of phytoremediation. The impact of soil chemical properties on willow root anatomy and the distribution of trace elements below-ground have rarely been studied. The effect of liming on root parameters, biomass allocation and trace element distribution in non-harvestable (coarse roots, fine roots, stumps) and harvestable plant parts (twigs and leaves) of Salix × smithiana was assessed at the end of a 4-year pot experiment with two trace element-polluted soils that differed in terms of soil pH. Stump biomass predominated in weakly acidic soil. In neutral soil, the majority of biomass was located in fine roots and stumps; the difference from other plant parts was minor. Trace elements were the most concentrated in fine roots. Translocation to above-ground biomass increased as follows: Pb roots roots). Lime application decreased the concentrations of mobile Cd and Zn and related levels in plants, improved biomass production and root parameters and increased the removal of all trace elements in weakly acidic soil. None or minimum differences in the monitored parameters were recorded for dolomite treatments in both soils. The dose and source of liming had crucial effects on root anatomy. Growing willows in limed trace element-polluted soils is a suitable measure for combination of two remediation strategies, i.e. phytoextraction of Cd and Zn and assisted phytostabilization of As and Pb.

Phytoextraction of initial cutting of Salix matsudana for Cd and Cu.

Science.gov (United States)

Wang, Wen-Wen; Cheng, Liu Ke; Hao, Jie Wei; Guan, Xin; Tian, Xing-Jun

2016-06-27

Salix species are widely used as vegetation filters because of their flourishing root system and fast growth rate. However, studies have yet to determine whether the root system functions in vegetable filters with mixed heavy metal (HM) pollution or whether initial cutting participates in the phytoextraction of HMs. This study aims to determine the function of the root system and initial cutting as vegetation filters in the absorption and accumulation of Cd and Cu. Thick (>1 cm in diameter) and fine (phytoextraction capacity of plants. The initial cuttings could also absorb and accumulate HMs in the early growth stages of willow without roots. Cu inhibited the plant absorption and accumulation of Cd and promoted Cd transport to shoots. Cd inhibited the Cu absorption of the root system. Our study provided essential data regarding woody species as vegetation filters of HM pollution.

Energy balance and evaporation of a short-rotation willow forest. Variation with season and stand development

Energy Technology Data Exchange (ETDEWEB)

Iritz, Z.

1996-10-01

Energy balance and evaporation of a short-rotation willow (Salix viminalis L.) forest was studied in relation to season and stand development. The developmental stage of the forest stand considerably influenced how the energy, received as net radiation, was partitioned between the connective fluxes and the storage components. The main part of the available energy was utilised for evaporation during most of the season. Only at the beginning of the season did the willow forest supply heat to the atmosphere. Later in the season, energy was taken from air and utilised for evaporation, which resulted in negative sensible heat fluxes. Soil heat storage was also a significant term in the energy balance and also strongly depended on canopy development. Changes in energy partitioning relative to leaf area indices indicated the existence of a threshold value for leaf area index of the developing canopy. The analysis suggested that the canopy of the willow forest could be considered as closed at a leaf area index of 2. It was further found that evaporation from well-irrigated willow forest occurred also during night-time, particularly in windy and dry weather conditions. The sources of nocturnal evaporation were both the canopy, i.e. indicating non-closed stomata, and the soil surface. Partitioning of the total evaporation into components was investigated using a physically-based model with a two-layer aboveground representation and a two-layer soil module. The model estimates evaporation with respect to developmental stage of the willow stand and also takes into account the interaction between the fluxes from the canopy and the soil surface. Good performance of the model indicated that, after further testing in drier conditions, it could be used as a tool for analysing the prerequisites for energy-forest establishment, and practical management of energy forest stands. 37 refs, 9 figs

Quality Testing of Short Rotation Coppice Willow Cuttings

Directory of Open Access Journals (Sweden)

Katrin Heinsoo

2018-06-01

Full Text Available The production and feasibility of Short Rotation Coppice depend on cutting early performance. The shoot and root biomass production of Salix cuttings in hydroponic conditions was studied. The amount of sprouted biomass after four weeks of growth depended on cutting the diameter, but the original position of the cutting along the rod or number of visible buds was not in correlation with biomass produced. Application of mineral fertilizer or soil originating from the willow plantation did not increase the total production. On the contrary, the addition of soil tended to decrease biomass production and we assumed this was a result of a shortage of light. Under the influence of fertilization, plants allocated greater biomass to roots. Comparison of different clones revealed that those with S. dasyclados genes tended to allocate less biomass to roots and the poorest-performing clone in our experiment, also had the lowest wood production in the plantation. The number of visible buds on the cutting was also clone-specific.

Long-term experimental warming, shading and nutrient addition affect the concentration of phenolic compounds in arctic-alpine deciduous and evergreen dwarf shrubs

DEFF Research Database (Denmark)

Hansen, Anja Hoff; Jonasson, Sven Evert; Michelsen, Anders

2006-01-01

-arctic, alpine ecosystem, we investigated the effects on carbon based secondary compounds (CBSC) and nitrogen in one dominant deciduous dwarf shrub, Salix herbacea × polaris and two dominant evergreen dwarf shrubs, Cassiope tetragona and Vaccinium vitis-idaea throughout one growing season. The main aims were...

Positive impact of bio-stimulators on growth and physiological activity of willow in climate change conditions

Science.gov (United States)

Piotrowski, Krzysztof; Romanowska-Duda, Zdzisława

2018-04-01

The aim of this research was to evaluate the physiological activity and growth of willow (Salix viminalis L.) plants cultivated under the conditions of adverse temperature and soil moisture content, and to assess the effect of the foliar application of Biojodis (1.0%) and Asahi SL (0.03%) bio-stimulators, or a mixture of Microcistis aeruginosa MKR 0105 and Anabaena PCC 7120 cyanobacteria under such changing growth conditions. The obtained results showed different reactions to the applied constant or periodically changed temperature and soil moisture content. The plants which grew at periodically changed adverse temperature (from -5 to 40oC) or in scantily (20% m.c.) or excessively (60% m.c.) watered soils, grew slowly, in comparison with those growing at 20oC and in optimally moistened soil (30% m.c.). Foliar application of Biojodis and Asahi SL cyanobacteria increased the growth of willow at optimal and adverse temperature or in scantily and excessively moistened soil. The changes in plant growth were associated with the changes in electrolyte leakage, activity of acid or alkaline phosphatases, RNase, index of chlorophyll content in leaves and gas exchange. The above indicates that the foliar application of the studied cyanobacteria and bio-stimulators partly alleviates the harmful impact of adverse temperature and water stress on growth and physiological activity of willow plants

The effect of hydrological regime on the metal bioavailability for the wetland plant species Salix cinerea

International Nuclear Information System (INIS)

Vandecasteele, Bart; Quataert, Paul; Tack, Filip M.G.

2005-01-01

The hydrological conditions on a site constitute one of the many factors that may affect the availability of potentially toxic trace metals for uptake by plants. Bioavailability of Cd, Mn and Zn in a contaminated dredged sediment-derived soil under different hydrological regimes was determined by measuring metal uptake by the wetland plant species Salix cinerea, both in field circumstances and in a greenhouse experiment. Longer submersion periods in the field caused lower Cd concentrations in leaves and bark. The wetland hydrological regime in the greenhouse experiment resulted in normal Cd and Zn concentrations in the leaves, while the upland hydrological regime resulted in elevated Cd and Zn concentrations in the leaves. Field observations and the greenhouse experiment suggest that a hydrological regime that creates or sustains a wetland is a potential management option that reduces metal bioavailability to willows. This would constitute a safe management option of metal-polluted, willow-dominated wetlands provided that wetland conditions can be maintained throughout the full growing season. - A hydrological regime aiming at wetland creation is a potential management option that favors reducing Cd plant availability in polluted freshwater wetlands

Translocation of Cd and Mn from Bark to Leaves in Willows on Contaminated Sediments: Delayed Budburst Is Related to High Mn Concentrations

Directory of Open Access Journals (Sweden)

Bart Vandecasteele

2015-04-01

Full Text Available Changes in the hydrology of sediments in tidal marshes or landfills may affect the uptake of metals in the vegetation. Leaf and stem samples of Salix cinerea (grey sallow were collected during four consecutive growing seasons at six contaminated plots on a polluted dredged sediment landfill and one plot on an uncontaminated reference site. The first three contaminated plots were already emerged in the first half of the first growing season, while the other three were submerged in the first year, but became increasingly dry over the study period. Foliar and stem cutting concentrations for Cd, Zn and Mn increased on the latter three plots over the four years. Willow bark contained high concentrations of Cd, Zn and Mn. In two consecutive greenhouse experiments with willow cuttings from different origins (uncontaminated and contaminated sites and grown under different soil conditions (uncontaminated and contaminated, we observed an important translocation of Mn from bark to shoots. In a third experiment with willow cuttings collected on soils with a range of heavy metal concentrations and, thus, with a broad range of Cd (4–67 mg/kg dry matter, Zn (247–660 mg/kg dry matter and Mn (38–524 mg/kg dry matter concentrations in the bark, high Mn concentrations in the bark were found to affect the budburst of willow cuttings, while no association of delayed budburst with Cd and Zn concentrations in the bark was found. We conclude that wood and, especially, bark are not a sink for metals in living willows. The high Mn concentrations in the bark directly or indirectly caused delayed or restricted budburst of the willow cuttings.

Vegetative reproduction capacities of floodplain willows--cutting response to competition and biomass loss.

Science.gov (United States)

Radtke, A; Mosner, E; Leyer, I

2012-03-01

While several studies on regeneration in Salicaceae have focused on seedling recruitment, little is known about factors controlling their vegetative reproduction. In two greenhouse experiments, we studied the response of floodplain willows (Salix fragilis, S. viminalis, S. triandra) to competition with Poa trivialis, and to shoot and root removal when planted as vegetative cuttings. In the first experiment, growth performance variables were analysed in relation to full competition, shoot competition, root competition and control, taking into account two different water levels. After 9 weeks, shoots were removed and the resprouting capacity of the bare cuttings was recorded. In the second experiment, the cutting performance of the three floodplain and an additional two fen willow species (S. cinerea, S. aurita) was compared when grown in three different soil compositions and with two different water levels. After 9 weeks, shoot and root biomass was removed and the bare cuttings were replanted to test their ability to resprout. Cutting performance and secondary resprouting were negatively affected by full and shoot competition while root competition had no or weak effects. The floodplain species performed better than the fen species in all soil types and water levels. Secondary resprouting capacity was also higher in the floodplain species, which showed an additional strong positive response to the previous waterlogging treatment. The results contribute to understanding of the vegetative regeneration ecology of floodplain willows, and suggest that the use of vegetative plantings in restoration plantings could be an effective strategy for recovering floodplain forests. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Cadmium in Salix. A study to show the capacity of Salix to remove cadmium from farmland

International Nuclear Information System (INIS)

Oestman, G.

1994-01-01

The aim of this report has been to show the ability of Salix to take up cadmium and how the uptake varies between different types of soil. The information that the results are based on has been obtained from analyses of soil and Salix. The samples were taken at five sites in the district around Lake Maelaren. Two or three stands were taken at each place. The factors studied were the pH, the organic matter content, and the concentration of cadmium in the soil. Salix has a good ability, relative to other crops, to remove cadmium from arable land. The cadmium uptake is 35 times higher with Salix than with straw or energy grass. Salix uptake of cadmium varies between 3 and 14% of the cadmium content in the soil that is accessible to plants. The present annual increase of cadmium in arable land is 1 g/ha, whereas the removal in a Salix plantation is 21 g Cd/ha, yr at an annual growth of 10 tonnes DM. If the Cd uptake is the same each year, then a total of 420 g Cd/ha is removed when Salix is grown over a 20-year period. This is a very large part of the topsoil's total cadmium content, which is 550 g/ha on average in Sweden. The investigation reveals no clear relationship between the Cd concentration in Salix and the concentration of Cd in the soil, the organic matter content or the pH. 22 refs, 4 figs, 2 tabs

Investigation of Solid Energy Potential of Wood and Bark Obtained from Four Clones of a 2-Year Old Goat Willow

International Nuclear Information System (INIS)

Han, Sim-Hee; Shin, Soo-Jeong

2014-01-01

To investigate the solid raw material characteristics of willow (Salix caprea) bark and woody core, this study analyzed overall chemical composition, monosaccharide composition, ash content, and main ash composition of both tree components. Significant differences were observed between the two in terms of chemical composition, carbohydrate composition, ash content, and major inorganics. The ash content in bark was 3.8–4.7%, compared with 0.6–1.1% in the woody core. Polysaccharide content in the woody core was 62.8–70.6% but was as low as 44.1–47.6% in the bark. The main hemicelluloses consisting of monosaccharides were xylose in the case of the woody core, and xylose, galactose, and arabinose in the case of bark. Woody core biomass of willow provides superior solid fuel raw material, as compared with bark biomass, with higher heating values, less ash content, and less slagging-causing material.

Investigation of Solid Energy Potential of Wood and Bark Obtained from Four Clones of a 2-Year Old Goat Willow

Energy Technology Data Exchange (ETDEWEB)

Han, Sim-Hee [Department of Forest Genetic Resources, Korea Forest Research Institute, Suwon (Korea, Republic of); Shin, Soo-Jeong, E-mail: soojshin@cbnu.ac.kr [Department of Wood and Paper Science, Chungbuk National University, Cheongju (Korea, Republic of)

2014-01-31

To investigate the solid raw material characteristics of willow (Salix caprea) bark and woody core, this study analyzed overall chemical composition, monosaccharide composition, ash content, and main ash composition of both tree components. Significant differences were observed between the two in terms of chemical composition, carbohydrate composition, ash content, and major inorganics. The ash content in bark was 3.8–4.7%, compared with 0.6–1.1% in the woody core. Polysaccharide content in the woody core was 62.8–70.6% but was as low as 44.1–47.6% in the bark. The main hemicelluloses consisting of monosaccharides were xylose in the case of the woody core, and xylose, galactose, and arabinose in the case of bark. Woody core biomass of willow provides superior solid fuel raw material, as compared with bark biomass, with higher heating values, less ash content, and less slagging-causing material.

Botanical Extracts from Rosehip (Rosa canina), Willow Bark (Salix alba), and Nettle Leaf (Urtica dioica) Suppress IL-1β-Induced NF-κB Activation in Canine Articular Chondrocytes

Science.gov (United States)

Shakibaei, Mehdi; Allaway, David; Nebrich, Simone; Mobasheri, Ali

2012-01-01

The aim of this study was to characterize the anti-inflammatory mode of action of botanical extracts from rosehip (Rosa canina), willow bark (Salix alba), and nettle leaf (Urtica dioica) in an in vitro model of primary canine articular chondrocytes. Methods. The biological effects of the botanical extracts were studied in chondrocytes treated with IL-1β for up to 72 h. Expression of collagen type II, cartilage-specific proteoglycan (CSPG), β1-integrin, SOX-9, COX-2, and MMP-9 and MMP-13 was examined by western blotting. Results. The botanical extracts suppressed IL-1β-induced NF-κB activation by inhibition of IκBα phosphorylation, IκBα degradation, p65 phosphorylation, and p65 nuclear translocation. These events correlated with downregulation of NF-κB targets including COX-2 and MMPs. The extracts also reversed the IL-1β-induced downregulation of collagen type II, CSPG, β1-integrin, and cartilage-specific transcription factor SOX-9 protein expression. In high-density cultures botanical extracts stimulated new cartilage formation even in the presence of IL-1β. Conclusions. Botanical extracts exerted anti-inflammatory and anabolic effects on chondrocytes. The observed reduction of IL-1β-induced NF-κB activation suggests that further studies are warranted to demonstrate the effectiveness of plant extracts in the treatment of OA and other conditions in which NF-κB plays pathophysiological roles. PMID:22474508

Botanical Extracts from Rosehip (Rosa canina), Willow Bark (Salix alba), and Nettle Leaf (Urtica dioica) Suppress IL-1β-Induced NF-κB Activation in Canine Articular Chondrocytes.

Science.gov (United States)

Shakibaei, Mehdi; Allaway, David; Nebrich, Simone; Mobasheri, Ali

2012-01-01

The aim of this study was to characterize the anti-inflammatory mode of action of botanical extracts from rosehip (Rosa canina), willow bark (Salix alba), and nettle leaf (Urtica dioica) in an in vitro model of primary canine articular chondrocytes. Methods. The biological effects of the botanical extracts were studied in chondrocytes treated with IL-1β for up to 72 h. Expression of collagen type II, cartilage-specific proteoglycan (CSPG), β1-integrin, SOX-9, COX-2, and MMP-9 and MMP-13 was examined by western blotting. Results. The botanical extracts suppressed IL-1β-induced NF-κB activation by inhibition of IκBα phosphorylation, IκBα degradation, p65 phosphorylation, and p65 nuclear translocation. These events correlated with downregulation of NF-κB targets including COX-2 and MMPs. The extracts also reversed the IL-1β-induced downregulation of collagen type II, CSPG, β1-integrin, and cartilage-specific transcription factor SOX-9 protein expression. In high-density cultures botanical extracts stimulated new cartilage formation even in the presence of IL-1β. Conclusions. Botanical extracts exerted anti-inflammatory and anabolic effects on chondrocytes. The observed reduction of IL-1β-induced NF-κB activation suggests that further studies are warranted to demonstrate the effectiveness of plant extracts in the treatment of OA and other conditions in which NF-κB plays pathophysiological roles.

Botanical Extracts from Rosehip (Rosa canina, Willow Bark (Salix alba, and Nettle Leaf (Urtica dioica Suppress IL-1β-Induced NF-κB Activation in Canine Articular Chondrocytes

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Mehdi Shakibaei

2012-01-01

Full Text Available The aim of this study was to characterize the anti-inflammatory mode of action of botanical extracts from rosehip (Rosa canina, willow bark (Salix alba, and nettle leaf (Urtica dioica in an in vitro model of primary canine articular chondrocytes. Methods. The biological effects of the botanical extracts were studied in chondrocytes treated with IL-1β for up to 72 h. Expression of collagen type II, cartilage-specific proteoglycan (CSPG, β1-integrin, SOX-9, COX-2, and MMP-9 and MMP-13 was examined by western blotting. Results. The botanical extracts suppressed IL-1β-induced NF-κB activation by inhibition of IκBα phosphorylation, IκBα degradation, p65 phosphorylation, and p65 nuclear translocation. These events correlated with downregulation of NF-κB targets including COX-2 and MMPs. The extracts also reversed the IL-1β-induced downregulation of collagen type II, CSPG, β1-integrin, and cartilage-specific transcription factor SOX-9 protein expression. In high-density cultures botanical extracts stimulated new cartilage formation even in the presence of IL-1β. Conclusions. Botanical extracts exerted anti-inflammatory and anabolic effects on chondrocytes. The observed reduction of IL-1β-induced NF-κB activation suggests that further studies are warranted to demonstrate the effectiveness of plant extracts in the treatment of OA and other conditions in which NF-κB plays pathophysiological roles.

Fiber length and pulping characteristics of switchgrass, alfalfa stems, hybrid poplar and willow biomasses.

Science.gov (United States)

Ai, Jun; Tschirner, Ulrike

2010-01-01

Switchgrass (Panicum virgatum), alfalfa stems (Medicago sativa), second year growth hybrid poplar (Populus) and willow (Salix spp.) were examined to determine fiber characteristics, pulping behavior and paper properties. Alfalfa stems and switchgrass both showed length weighted average fiber length (LWW) of 0.78 mm, a very narrow fiber length distribution and high fines content. Willow and hybrid poplar have lower fines content but a very low average fiber length (0.42 and 0.48 mm LWW). In addition, the four biomass species showed distinctly different chemical compositions. Switchgrass was defibered successfully using Soda and Soda Anthraquinone (AQ) pulping and demonstrated good paper properties. Both fast-growing wood species pulped well using the Kraft process, and showed acceptable tensile strength, but low tear strength. Alfalfa stems reacted very poorly to Soda and Soda AQ pulping but responded well to Kraft and Kraft AQ. Pulps with tensile and tear strength considerably higher than those found for commercial aspen pulps were observed for alfalfa. All four biomass species examined demonstrated low pulp yield. The highest yields were obtained with poplar and switchgrass (around 43%). Considering the short fibers and low yields, all four biomass types will likely only be used in paper manufacturing if they offer considerable economic advantage over traditional pulp wood.

VOC emissions and carbon balance of two bioenergy plantations in response to nitrogen fertilization: A comparison of Miscanthus and Salix.

Science.gov (United States)

Hu, Bin; Jarosch, Ann-Mareike; Gauder, Martin; Graeff-Hönninger, Simone; Schnitzler, Jörg-Peter; Grote, Rüdiger; Rennenberg, Heinz; Kreuzwieser, Jürgen

2018-06-01

Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from Miscanthus and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha -1 yr -1 ). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH . reactivity resulting from individual VOC emitted. Total VOC emissions from Salix was 1.5- and 2.5-fold higher compared to Miscanthus in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in Salix (80-130 μg g -1 DW h -1 ), whereas it was negligible in Miscanthus. We identified twenty-eight VOC compounds, which were released by Miscanthus with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by Salix. OH . reactivity from VOC released by Salix was ca. 8-times higher than that of Miscanthus. N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized Miscanthus compared to Salix together with the considerably lower OH . reactivity per weight unit of biomass produced, qualified the C 4 -perennial grass Miscanthus as a superior source of future

Enzymatic Saccharification of Shrub Willow Genotypes with Differing Biomass Composition for Biofuel Production

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Michelle J. Serapiglia

2013-03-01

Full Text Available In the conversion of woody biomass feedstocks into liquid fuel ethanol, the pretreatment process is the most critical and costly step. Variations in biomass composition based on genetic differences or environmental effects have a significant impact on the degree of accessibility accomplished by pretreatment and subsequent sugar release by enzymatic hydrolysis. To evaluate this, biomass from 10 genetically diverse, genotypes of shrub willow (Salix spp. was pretreated with a hot-water process at two levels of severity, hydrolyzed using a combination of two commercial enzyme cocktails, and the release of hexose and pentose monomers was quantified by HPLC. Among the genotypes selected for analysis, cellulose content ranged from 39 to 45% (w/w and lignin content ranged from 20 to 23% (w/w at harvest. Differences in the effectiveness of the pretreatment process were observed among the various willow genotypes. Correlations were identified between total sugar release and % cellulose and % lignin content. There was a significant effect of pretreatment severity on polysaccharide accessibility, but the response to pretreatments was different among the genotypes. At the high severity pretreatment ‘SV1’ was the least recalcitrant with sugar release representing as much as 60% of total biomass. These results suggest that structural, as well as chemical characteristics of the biomass may influence pretreatment and hydrolytic efficiency.

Cultural Resources Investigation of a Proposed Flood Control Project along the Sheyenne River, at West Fargo, Cass County, North Dakota. Phase I.

Science.gov (United States)

1988-01-15

cottonwood (Po2ulus salrgenti), sumac (Ehus sp.), peach and sandbar willows (Salix amvdaloides; . terio), and slippery elm (Ulmus rubra). 3.4.2 Bluestem...forest of elm , oak, ash, hackberry, cottonwood, and aspen along the major streams. Archaeological evidence indicates that prehistoric people along the...black willow (Salix nifra), and American elm (Ulmus amicnan). Other components include: boxelder (Acer neaundo), red maple (A. Subrum), silver maple (A

Salix transect of Europe: structured genetic variation and isolation-by-distance in the nettle psyllid, Trioza urticae (Psylloidea, Hemiptera), from Greece to Arctic Norway

Science.gov (United States)

Wonglersak, Rungtip; Cronk, Quentin; Percy, Diana

2017-01-01

Abstract Background The common nettle (Urtica dioica L.) is co-associated with willows (Salix spp.) in riparian habitats across Europe. We sampled the widespread nettle psyllid, Trioza urticae (Linné, 1758), from Urtica in willow habitats on a megatransect of Europe from the Aegean to the Arctic Ocean. The aim of this study was to use an unusually widespread insect to assess the influence of geographic distances and natural geographic barriers on patterns of genetic variation and haplotype distribution. New information Phylogeographic analysis using DNA sequences of two mtDNA regions, COI and cytB, shows that T. urticae specimens are organized into four regional groups (southern, central, northern and arctic). These groups are supported by both phylogenetic analysis (four geographically-based clades) and network analysis (four major haplotype groups). The boundary between southern and central groups corresponds to the Carpathian Mountains and the boundary between the central and northern groups corresponds to the Gulf of Finland. Overall these groups form a latitudinal cline in genetic diversity, which decreases with increasing latitude. PMID:28325977

Impact of anthropogenic forest contamination on radioresistance of woody plant seed

International Nuclear Information System (INIS)

Yushkov, P.I.

2004-01-01

Radioresistance of seeds of bay willow (Salix pentandra L.) and great sallow willow (Salix caprea L.) from forests chronically affected and non-affected by acidic (SO 2 , NO x , HF, etc.) industries has been studied and compared. Bay willow seeds of 6 harvests showed no difference in radioresistance. However, seeds of both species manifested strong synchronous variability in resistance to preplant exposure. Also, no influence was observed of mother plant gas content on great sallow willow seeds of different harvests. Data obtained confirm similar results of previous studies conducted by the author (1987) to identify the impact of plant gas content on radioresistance of seeds and seedlings of pine (Pinus sylvestris L.) and birch (Betula verrucosa Erh.). (author)

Vegetation Evaluation and Recommendations: Dredge Material Placement Areas and Adjacent Lands, Kaskaskia River Navigation Project, New Athens to Fayetteville.

Science.gov (United States)

1981-06-03

cottonwood), Salix interior (sandbar willow), Salix nigra (black willow), and Ulmus rubra * ( slippery elm ) . Somewhat drier sites with a predominance of fine...Dutch Elm Disease. *Ulmus rubra Muhl. SLIPPERY ELM . Common tree in floodplain woods; also occasional in DMP. *Valerianella radiata (L.) Dufr. CORN... elm ), Carya tomentosa (mocker- nut hickory), and Quercus bicolor (swamp white oak). Shrubs and woody vines play a major role in the ecology of these

Treatment of a Textile Effluent by Electrochemical Oxidation and Coupled System Electooxidation–Salix babylonica

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Alejandra Sánchez-Sánchez

2018-01-01

Full Text Available The removal of pollutants from textile wastewater via electrochemical oxidation and a coupled system electrooxidation—Salix babylonica, using boron-doped diamond electrodes was evaluated. Under optimal conditions of pH 5.23 and 3.5 mA·cm−2 of current density, the electrochemical method yields an effective reduction of chemical oxygen demand by 41.95%, biochemical oxygen demand by 83.33%, color by 60.83%, and turbidity by 26.53% at 300 minutes of treatment. The raw and treated wastewater was characterized by infrared spectroscopy to confirm the degradation of pollutants. The wastewater was oxidized at 15-minute intervals for one hour and was placed in contact with willow plants for 15 days. The coupled system yielded a reduction of the chemical oxygen demand by 14%, color by 85%, and turbidity by 93%. The best efficiency for the coupled system was achieved at 60 minutes, at which time the plants achieved more biomass and photosynthetic pigments.

Pollen viability of Salix myrtilloides L. – an endangered species in Poland

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Magdalena Pogorzelec

2016-12-01

Full Text Available Salix myrtilloides L. (swamp willow is the most endangered species among the boreal Salix species in Poland. The number and size of its population have been decreasing constantly since the 1990s. The main aim of the study was to determine the viability of collected S. myrtilloides pollen and optimal conditions for its in vitro germination. The pollen of S. myrtilloides was collected from 25 male individuals from a population growing in the mid-forest peat bog Dekowina (Sobibór Landscape Park in May 2014. Two methods were applied to estimate the viability of fresh and stored pollen: staining pollen with 2% acetocarmine solution and in vitro germinability. Various temperature (11°C, 23°C and light conditions as well as different concentrations of glucose (1%, 2.5%, 5%, or 7.5% were tested for the optimization of in vitro germination. We documented relatively high S. myrtilloides pollen viability. Pollen tube growth was found to be largely affected by both glucose content in the medium and thermal conditions during germination. Fresh pollen germinated most effectively on the medium with 2.5% glucose (stored pollen – in 5% glucose, at 23°C and in the presence of light. We conclude that pollen viability of S. myrtilloides does not seem to be a limiting factor for reproductive success. Moreover, the pollen is not sterile even after storage for 12 months. The S. myrtilloides individuals from the Dekowina peat bog produce viable pollen grains that are able to germinate and therefore it can be used to pollinate other populations present in the Polesie Lubelskie region for gene pool enrichment.

Development of a method for testing the susceptibility of Salix alba to Erwinia salicis

Energy Technology Data Exchange (ETDEWEB)

Dingjan-Versteegh, A M; de Kam, M [Institute for Forestry and Urban Ecology, Wageningen (Netherlands)

1990-01-01

Salix is one of the faster growing tree species that has potential for biomass plantations in Europe. This potential, however, is limited by the occurrence of a vascular disease caused by the bacterium Erwinia salicis (Day) Chester. Selection and breeding of disease resistance is hampered by insufficient knowledge of the infection biology and ecology of the pathogen. The availability of specific antisera is of vital importance in the study of the infection biology and in monitoring bacterial populations inside the host. Therefore, one of the aims of the research was to improve the antisera. The composition of the soluble antigens of E. salicis was studied by enzyme-linked immunosorbent assay (ELISA), polyacrylamide gel electrophoresis (PAGE) and electro-immunoblotting. Antiserum prepared to whole cells of E. salicis mainly contains antibodies to bacterial surface antigens or to soluble antigens. ELISA demonstrated the presence of bacterial soluble antigens in leaves of diseased willow trees and also in leaves of willow shoots which were placed in a solution of bacterial soluble antigens. An inoculation experiment was carried out to ascertain if there is a statistically significant correlation between plant water potential and response to artificial inoculation with E. salicis. To elucidate the mechanisms involved in pathogenicity and virulence of E. salicis, attempts were made to isolate the plasmids of the bacterium, however, it appears that E. salicis does not have plasmids. In collaboration with Ch. Maceau (21), the E. salicis genome was isolated and a genomic library was constructed in E. coli. 28 refs., 10 figs., 4 tabs.

Eighteen microsatellite loci in Salix arbutifolia (Salicaceae) and cross-species amplification in Salix and Populus species.

Science.gov (United States)

Hoshikawa, Takeshi; Kikuchi, Satoshi; Nagamitsu, Teruyoshi; Tomaru, Nobuhiro

2009-07-01

Salix arbutifolia is a riparian dioecious tree species that is of conservation concern in Japan because of its highly restricted distribution. Eighteen polymorphic loci of dinucleotide microsatellites were isolated and characterized. Among these, estimates of the expected heterozygosity ranged from 0.350 to 0.879. Cross-species amplification was successful at 9-13 loci among six Salix species and at three loci in one Populus species. © 2009 Blackwell Publishing Ltd.

Evaluation report. Willow; Evalueringsrapport. Pil

Energy Technology Data Exchange (ETDEWEB)

Bang Bilgaard, H. [AgroTech A/S, Skejby, Aarhus (Denmark); Eide, T.; Gertz, F. [Videncentret for Landbrug, Skejby, Aarhus (Denmark)] [and others

2012-10-15

This evaluation report brings together the main findings of willows activities in the BioM project in the period 2010-2012. The report contains sections relating to growing and cultivation conditions, energy production, environmental effects, landscape aspects, harvesting techniques, economics, and organization, marketing, and business effects, and a description of willow cultivation on a large scale in the project area in western Jutland, Denmark. The report concludes with an overall assessment of willow cultivation for the production of sustainable bioenergy. (LN)

Impacts of paper sludge and manure on soil and biomass production of willow

International Nuclear Information System (INIS)

Quaye, Amos K.; Volk, Timothy A.; Hafner, Sasha; Leopold, Donald J.; Schirmer, Charles

2011-01-01

Land application of organic wastes to short rotation woody crops (SRWC) can reduce the environmental impacts associated with waste disposal and enhance the productivity of biomass production systems. Understanding the potential impacts of organic amendments however, requires the examination of changes in soil characteristics and plant productivity. This study was conducted to evaluate the effect of paper sludge and dairy manure on biomass production of shrub willow (Salix dasyclados SV1) and to determine the impacts of these amendments on soil chemical properties. Treatments included urea, dairy manure and paper sludge separately and in combination, and a control. These materials were applied in the summer of 2005 to two fields of SV1 at different stages of growth: An old field with one year old shoots on a 10 year old root system and a young field which was beginning regrowth after being coppiced at the end of its first growing season. Foliar nutrient concentrations and soil chemical properties were analyzed at the end of the second growing season after treatment application to determine plant response to the fertilization regimes and to determine the effects of fertilization on soil characteristics. Fertilization did not increase biomass production in either field. However, application of the N-poor paper sludge did not reduce yield either. In general, fertilization did not influence soil or foliar chemistry, although there were some exceptions. The lack of response observed in this study is probably related to the nutrient status of the site or losses of applied nutrients. -- Highlights: → The fertilization treatments did not have any significant effect biomass production. → Application of paper sludge did not reduce willow biomass yield in both fields. → Foliar N concentration of willow crops in this study is in the range considered for optimal growth. → The limited response of foliar nutrients to fertilization indicates that the site was not limited by

Distribution of P, K, Ca, Mg, Cd, Cu, Fe, Mn, Pb and Zn in wood and bark age classes of willows and poplars used for phytoextraction on soils contaminated by risk elements.

Science.gov (United States)

Zárubová, Pavla; Hejcman, Michal; Vondráčková, Stanislava; Mrnka, Libor; Száková, Jiřina; Tlustoš, Pavel

2015-12-01

Fast-growing clones of Salix and Populus have been studied for remediation of soils contaminated by risk elements (RE) using short-rotation coppice plantations. Our aim was to assess biomass yield and distributions of elements in wood and bark of highly productive willow (S1--[Salix schwerinii × Salix viminalis] × S. viminalis, S2--Salix × smithiana clone S-218) and poplar (P1--Populus maximowiczii × Populus nigra, P2--P. nigra) clones with respect to aging. The field experiment was established in April 2008 on moderately Cd-, Pb- and Zn- contaminated soil. Shoots were harvested after four seasons (February 2012) and separated into annual classes of wood and bark. All tested clones grew on contaminated soils, with highest biomass production and lowest mortality exhibited by P1 and S2. Concentrations of elements, with exception of Ca and Pb, decreased with age and were higher in bark than in wood. The Salix clones were characterised by higher removal of Cd, Mn and Zn compared to the Populus clones. Despite generally higher RE content in young shoots, partly due to lower wood/bark ratios and higher RE concentrations in bark, the overall removal of RE was higher in older wood classes due to higher biomass yield. Thus, longer rotations seem to be more effective when phytoextraction strategy is considered. Of the four selected clones, S1 exhibited the best removal of Cd and Zn and is a good candidate for phytoextraction.

Factors Affecting Diet Variation in the Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica: Conservation Implications.

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Ricardo García-González

Full Text Available The Pyrenean rock ptarmigan (Lagopus muta pyrenaica lives at one of the southernmost limits of the ptarmigan range. Their small population sizes and the impacts of global changes are limiting factors in the conservation of this threatened subspecies. An effective conservation policy requires precise basic knowledge of a species' food and habitat requirements, information that is practically non-existent for this Pyrenean population. Here, we describe the diet of a ptarmigan population in the Eastern Pyrenees, the environmental factors influencing its variability and the relationship between diet floristic composition and quality. Diet composition was determined by microhistological analysis of faeces and diet quality was estimated from free-urate faecal N content. Our results show that grouse diet is based mainly on arctic-alpine shrubs of the Ericaceae family, as well as dwarf willows (Salix spp. and Dryas octopetala. The most frequently consumed plant species was Rhododendron ferrugineum, but its abundance in the diet was negatively related to the diet nitrogen content. Conversely, the abundance of Salix spp., grass leaves and arthropods increased the nitrogen content of the diet. Seasonality associated with snow-melting contributed the most to variability in the Pyrenean ptarmigan diet, differentiating winter from spring/summer diets. The latter was characterised by a high consumption of dwarf willows, flowers, arthropods and tender forb leaves. Geographic area and sex-age class influenced diet variability to a lesser extent. Current temperature increases in the Pyrenees due to global warming may reduce the persistence and surface area of snow-packs where preferred plants for rock ptarmigan usually grow, thus reducing food availability. The high consumption of Rh. ferrugineum characterised the diet of the Pyrenean population. Given the toxicity of this plant for most herbivores, its potential negative effect on Pyrenean ptarmigan populations

Structural and productive-developmental characteristics of white willow plantations of different density on humogley in Donji Srem

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Andrašev Siniša

2012-01-01

Full Text Available The study was conducted in two plantations of white willow (Salix alba L. in Donji Srem on the humogley soil type (hydromorphic black soil, which belongs to a narrow-leaved ash forest with remote sedge (Carici remotae - Fraxinetum angustifoliae Jov. et Tom., 1979. The plantations are located in the same depression. The SP (sample plot-1 plantation is 21 years old with a 6×6 m planting spacing, and the SP-2 plantation is 27 years old with a 3×3m planting spacing. Elements of stem growth in the SP-1 plantation showed that with the white willow planting spacing of 6×6 m and a planned 25-year production cycle it is possible to obtain about 250 m3•ha-1 of timber volume, with an 80% net share of technical wood and a 20 % share of pulp wood. The plantation in SP-2 is at the age, which is well above the optimum age in terms of rational management, and the total volume at the age of 27 years is about 300 m3•ha-1, with a 53.7% net share of technical wood and a 46.3% share of pulpwood. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Istraživanje klimatskih promena na životnu sredinu: praćenje uticaja, adaptacija i ublažavanje

Frost related dieback in Estonian energy plantations of willows in relation to fertilisation and pathogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Cambours, M.A.; Nejad, P. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 07 Uppsala (Sweden); Heinsoo, K. [Institute of Zoology and Botany, Estonian Agricultural University, Riia 181, 51014 Tartu (Estonia); Granhall, U. [Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, 750 07 Uppsala (Sweden)

2006-03-15

Two 9-year old Estonian Salix plantations suffering from dieback were studied: one situated on poor mineral soil and divided into fertilised and unfertilised plots (Saare plantation) and another growing on a well-decomposed and nitrogen-rich organic soil, without fertiliser application (Kambja plantation). Bacteria from internal tissues of visually damaged shoots from seven clones were isolated in spring and autumn. The strains were subsequently biochemically characterised and tested for ice nucleation activity and pathogenicity on Salix. Some strains were also analysed with 16S rRNA. High numbers of culturable bacteria were found, belonging mainly to Erwinia, Sphingomonas, Pseudomonas and Xanthomonas spp. Fertilised plots were significantly more colonised by bacteria than unfertilised plots and also more extensively damaged, showing a lower density of living plants after 7 years of culture. More ice nucleation active (INA) strains were found in Saare fertilised plots and at Kambja than in Saare unfertilised plots. Likewise, most pathogenic strains were isolated from Saare fertilised plots and from Kambja. For some of the willow clones studied, dieback appeared to be related to both clonal frost sensitivity and abundance of INA and pathogenic bacteria. The plantations probably suffered from the presence of high amounts of pathogens and from frost related injuries aggravated by INA bacteria. Most probably the fertilisation at Saare and the nitrogen-rich soil at Kambja created a favourable environment for bacterial development and led to high dieback levels after the first harvest. (author)

A profile and analysis of willow growers in Sweden

International Nuclear Information System (INIS)

Rosenqvist, H.; Roos, A.; Ling, E.; Hektor, B.

1999-01-01

Willow plantations on Swedish farmland increased considerably between 1991 and 1996. The main driving forces behind this development were (1) the 1991 introduction of an agriculture deregulation policy in Sweden which created lower grain prices and simultaneously introduced compensation for set-aside land and subsidies for willow plantations on surplus arable land, (2) higher taxes on fossil fuels, and (3) the existence of a biofuel market in Sweden based on forest fuels. This paper presents a statistical study of 1,158 willow growers in southern and central-eastern Sweden. The resulting profile of growers will help policy makers and agents in the bioenergy business design information campaigns and marketing strategies. Willow growers are described according to geographical distribution, willow parcel sizes, farm sizes, and farm types. They are compared with the population of farmers who are not growing willow. Willow growers are more often between 50-65 years of age, and they have larger farms than non-willow growers. They are less often focused on animal and milk production and more often on cereal and food crop production than are other farmers. (author)

Willow Bark

Science.gov (United States)

... willow bark extract, ginger root concentrate, boswellia extract, turmeric root extract, cayenne, and hyaluronic acid (Instaflex Joint ... Sensitivity to aspirin: People with ASTHMA, STOMACH ULCERS, DIABETES, GOUT, HEMOPHILIA, HYPOPROTHROMBINEMIA, or KIDNEY or LIVER DISEASE ...

Growth, physiological response and phytoremoval capability of two willow clones exposed to ibuprofen under hydroponic culture.

Science.gov (United States)

Iori, Valentina; Zacchini, Massimo; Pietrini, Fabrizio

2013-11-15

Ibuprofen (IBU) is one of the most widespread pharmaceuticals in the aquatic ecosystem, despite the high removal rate that occurs in wastewater treatment plants. Phytoremediation represents a technology to improve the performance of existing wastewater treatment. This study was conducted under hydroponics to evaluate the ability of Salicaceae plants to tolerate and reduce IBU concentration in contaminated water. To this end, we combined growth, physiological and biochemical data to study the effects of different IBU concentrations on two clones of Salix alba L. Data demonstrated that clone SS5 was more tolerant and showed a higher ability to reduce IBU concentration in the solution than clone SP3. The high tolerance to IBU shown by SS5 was likely due to several mechanisms including the capacity to maintain an elevated photosynthetic activity and an efficient antioxidative defence. These results illustrate the remarkable potential of willow to phytoremediate IBU-contaminated waters in natural and constructed wetlands. Copyright © 2013 Elsevier B.V. All rights reserved.

Adsorption Property and Mechanism of Oxytetracycline onto Willow Residues

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Di Wang

2017-12-01

Full Text Available To elucidate the adsorption property and the mechanism of plant residues to reduce oxytetracycline (OTC, the adsorption of OTC onto raw willow roots (WR-R, stems (WS-R, leaves (WL-R, and adsorption onto desugared willow roots (WR-D, stems (WS-D, and leaves (WL-D were investigated. The structural characterization was analyzed by scanning electron microscopy, Fourier-transform infrared spectra, and an elemental analyzer. OTC adsorption onto the different tissues of willow residues was compared and correlated with their structures. The adsorption kinetics of OTC onto willow residues was found to follow the pseudo-first-order model. The isothermal adsorption process of OTC onto the different tissues of willow residues followed the Langmuir and Freundlich model and the process was also a spontaneous endothermic reaction, which was mainly physical adsorption. After the willow residues were desugared, the polarity decreased and the aromaticity increased, which explained why the adsorption amounts of the desugared willow residues were higher than those of the unmodified residues. These observations suggest that the raw and modified willow residues have great potential as adsorbents to remove organic pollutants.

Meta-transcriptomics indicates biotic cross-tolerance in willow trees cultivated on petroleum hydrocarbon contaminated soil.

Science.gov (United States)

Gonzalez, Emmanuel; Brereton, Nicholas J B; Marleau, Julie; Guidi Nissim, Werther; Labrecque, Michel; Pitre, Frederic E; Joly, Simon

2015-10-12

High concentrations of petroleum hydrocarbon (PHC) pollution can be hazardous to human health and leave soils incapable of supporting agricultural crops. A cheap solution, which can help restore biodiversity and bring land back to productivity, is cultivation of high biomass yielding willow trees. However, the genetic mechanisms which allow these fast-growing trees to tolerate PHCs are as yet unclear. Salix purpurea 'Fish Creek' trees were pot-grown in soil from a former petroleum refinery, either lacking or enriched with C10-C50 PHCs. De novo assembled transcriptomes were compared between tree organs and impartially annotated without a priori constraint to any organism. Over 45% of differentially expressed genes originated from foreign organisms, the majority from the two-spotted spidermite, Tetranychus urticae. Over 99% of T. urticae transcripts were differentially expressed with greater abundance in non-contaminated trees. Plant transcripts involved in the polypropanoid pathway, including phenylalanine ammonia-lyase (PAL), had greater expression in contaminated trees whereas most resistance genes showed higher expression in non-contaminated trees. The impartial approach to annotation of the de novo transcriptomes, allowing for the possibility for multiple species identification, was essential for interpretation of the crop's response treatment. The meta-transcriptomic pattern of expression suggests a cross-tolerance mechanism whereby abiotic stress resistance systems provide improved biotic resistance. These findings highlight a valuable but complex biotic and abiotic stress response to real-world, multidimensional contamination which could, in part, help explain why crops such as willow can produce uniquely high biomass yields on challenging marginal land.

RESISTÊNCIA DO VIMEIRO, Salix spp. (Salicaceae, À PRAGAS E DOENÇAS

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Pedro Boff

2007-03-01

Full Text Available Este trabalho teve o objetivo de avaliar a reação de resistência a pragas e doenças de clones locais do vimeiro comum, Salix x rubens, e de espécies introduzidas da Argentina, Chile, Alemanha e França. Três experimentos foram conduzidos em campo no ciclo de cultivo 2003/2004, em diferentes ecossistemas do Planalto Serrano Catarinense. As avaliações de resistência constaram da estimativa de danos causados pelos insetos e da severidade de doenças foliares. No conjunto de todas as avaliações, os acessos – genótipos introduzidos – EEL_10 (Salix nigra, EEL_08 (Salix sp., EEL_02 (Salix x rubens, EEL_13 (Salix sp., EEL_09 (Salix alba, e EEL_20 (Salix sp. foram os mais resistentes ao ataque de pragas e doenças. Dada a reação diferenciada dos acessos quanto ao ataque de doenças e pragas, as próximas ações de pesquisa devem proceder aos testes de artesanato para verificar a sua adequação à demanda para confecção de peças finas.

Does SO{sub 2} fumigation change the chemical defense of woody plants: the effect of short-term SO{sub 2} fumigation on the metabolism of deciduous Salix Myrsinifolia plants

Energy Technology Data Exchange (ETDEWEB)

Julkunen-Tiitto, R.; Lavola, A.; Kainulainen, P. [University of Joensuu, Joensuu (Finland). Dept. of Biology

1995-08-01

The effect of a moderate increase in atmospheric sulfur dioxide on the production of phenolic secondary chemicals, soluble sugars and phytomass distribution within plants was investigated in six willow ({ital Salix myrsinifolia Salisb}) clones. The plants were cultivated for 3 weeks under 0.11 ppm of SO{sub 2} (300{mu}g m{sup -3}). The production of salicin and chlorogenic acid was significantly reduced under increased SO{sub 2}. However, salicortin, 2{prime}-O-acetylsalicortin, (+)-catechin and two unknown phenolics did not show any clear trend. The increase in SO{sub 2} did not affect the glucose, fructose and sucrose contents. The final weight of the SO{sub 2}-treatment plants was significantly greater than that of the control plants: the leaf, stem and root phytomass was from 14 to 48% greater under increased SO{sub 2}. All the clones showed the same trend, although there was a significant variation in phytomass production. Results indicate, although not consistently, that even a short-term exposure of enhanced atmospheric SO{sub 2} may change moderately the accumulation pattern of willow phenolics. 20 refs., 2 tabs.

Combined enhancements of temperature and UVB influence growth and phenolics in clones of the sexually dimorphic Salix myrsinifolia

Energy Technology Data Exchange (ETDEWEB)

Nybakken, L.; Hoerkkae, R.; Julkunen-Tiitto, R. (Univ. of Eastern Finland. Dept. of Biology, Joensuu (Finland))

2012-08-15

Although several climatic factors are expected to change simultaneously in the future, the effect of such combined changes on plants have seldom been tested under field conditions. We report on a field experiment with dark-leaved willow, Salix myrsinifolia, subjected to enhancements in ultraviolet-A (UVA), UVB radiation and temperature, setup in Joensuu, Eastern Finland. S. myrsinifolia is a dioecious species, known as an important food plant for many herbivores. Cuttings of eight clones, four of each sex, of dark-leaved willow were planted in the field in spring 2009. In both 2009 and 2010, the total biomass increased significantly with temperature, and in 2010 there was an additive effect of UVB radiation. Both height and diameter increased with temperature in 2009, while the effect on height growth ceased in 2010. Males had greater diameter growth than females in 2010. Most phenolic compounds in the leaves decreased under enhanced temperature in both growing seasons. In 2010, four of six salicylates increased in response to enhanced temperature. Some quercetin derivatives increased under enhanced UVB radiation. Females had higher concentrations of chlorogenic acids than males, and while enhanced temperature reduced chlorogenic acid in females only, luteolins were reduced only in males. In summary, the combined enhancements gave no effects in addition to those that appeared under the single-factor treatments, except for the additive effect of UVB on temperature-increased biomass. The few gender-related differences found in response to climate change do not allow any marked expectations of future climate-induced changes in sex ratios. (Author)

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge

2011-01-01

Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination......, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

Salix transect of Europe: variation in ploidy and genome size in willow-associated common nettle, Urtica dioica L. sens. lat., from Greece to arctic Norway.

Science.gov (United States)

Cronk, Quentin; Hidalgo, Oriane; Pellicer, Jaume; Percy, Diana; Leitch, Ilia J

2016-01-01

The common stinging nettle, Urtica dioica L. sensu lato, is an invertebrate "superhost", its clonal patches maintaining large populations of insects and molluscs. It is extremely widespread in Europe and highly variable, and two ploidy levels (diploid and tetraploid) are known. However, geographical patterns in cytotype variation require further study. We assembled a collection of nettles in conjunction with a transect of Europe from the Aegean to Arctic Norway (primarily conducted to examine the diversity of Salix and Salix -associated insects). Using flow cytometry to measure genome size, our sample of 29 plants reveals 5 diploids and 24 tetraploids. Two diploids were found in SE Europe (Bulgaria and Romania) and three diploids in S. Finland. More detailed cytotype surveys in these regions are suggested. The tetraploid genome size (2C value) varied between accessions from 2.36 to 2.59 pg. The diploids varied from 1.31 to 1.35 pg per 2C nucleus, equivalent to a haploid genome size of c. 650 Mbp. Within the tetraploids, we find that the most northerly samples (from N. Finland and arctic Norway) have a generally higher genome size. This is possibly indicative of a distinct population in this region.

Phytoextraction with Salix viminalis in a moderately to strongly contaminated area.

Science.gov (United States)

Tőzsér, Dávid; Harangi, Sándor; Baranyai, Edina; Lakatos, Gyula; Fülöp, Zoltán; Tóthmérész, Béla; Simon, Edina

2018-02-01

We tested the suitability of Salix viminalis for phytoextraction with the analysis of selected elements in soil, root, and leaf, and by visual tree condition assessment in an area with varying levels of contamination. Bioconcentration factor (BCF) and translocation factor (TF) were used to assess the phytoextraction potential of willows. The middle part of the study area was strongly contaminated, while the northern and southern parts were moderately contaminated. We found increasing element concentrations toward deeper layers. Mean concentrations of elements in roots were similar among the three parts, while in leaves the highest concentrations were found in the strongly contaminated part of the study area. Tree condition scores were the lowest in the strongly contaminated part of the study area, which was caused by Al, Ca, K, Mg, Ni, Sr, and Zn concentration. These elements induced leaf disease and leaf feeders. The highest BCF values were found for Cu, Fe, Mn, and Zn in root, and for Cd and Zn in leaves, indicating that S. viminalis had high accumulation potential of these elements. Furthermore, TF values were high for Cd, Mn, Sr, and Zn. Our results also demonstrated that soil element composition has major influence on the condition of S. viminalis individuals. Furthermore, visual condition assessment was found to be a useful tool to assess the phytoextraction potential of trees.

Analysis of genetic diversity in female, male and half sibs willow ...

African Journals Online (AJOL)

The genetic diversity among genotypes of Salix sp. was found to be high, suggesting the importance and feasibility of introducing elite genotypes from different origins for Salix germplasm conservation and breeding programs. Keywords: Salix sp., half sibs, molecular markers, genomic DNA fingerprinting. African Journal of ...

The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

Energy Technology Data Exchange (ETDEWEB)

Wuytack, Tatiana, E-mail: tatiana.wuytack@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Wuyts, Karen, E-mail: karen.wuyts@ugent.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Van Dongen, Stefan, E-mail: stefan.vandongen@ua.ac.be [Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Baeten, Lander, E-mail: lander.baeten@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Kardel, Fatemeh, E-mail: fatemeh.kardel@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Verheyen, Kris, E-mail: kris.verheyen@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode, Melle (Belgium); Samson, Roeland, E-mail: roeland.samson@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

2011-10-15

We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO{sub x} and O{sub 3} concentrations had only a marginal influence. The influence of SO{sub 2} concentration was negligible. Although our data analysis suggests a relationship between SLA and NO{sub x}/O{sub 3} concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: > Leaf characteristics of white willow as possible bio-indicators for air quality. > Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. > Shadow increases specific leaf area. > NO{sub x} and O{sub 3} change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NO{sub x} and decreasing O{sub 3} concentration, while leaf asymmetry did not respond to air pollution

The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

International Nuclear Information System (INIS)

Wuytack, Tatiana; Wuyts, Karen; Van Dongen, Stefan; Baeten, Lander; Kardel, Fatemeh; Verheyen, Kris; Samson, Roeland

2011-01-01

We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO x and O 3 concentrations had only a marginal influence. The influence of SO 2 concentration was negligible. Although our data analysis suggests a relationship between SLA and NO x /O 3 concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: → Leaf characteristics of white willow as possible bio-indicators for air quality. → Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. → Shadow increases specific leaf area. → NO x and O 3 change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NO x and decreasing O 3 concentration, while leaf asymmetry did not respond to air pollution

Resistência do vimeiro, Salix spp. (Salicaceae, à pragas e doenças.

Directory of Open Access Journals (Sweden)

Jamille Casa

2010-08-01

Full Text Available Este trabalho teve o objetivo de avaliar a reação de resistência a pragas e doenças de clones locais do vimeiro comum, Salix x rubens, e de espécies introduzidas da Argentina, Chile, Alemanha e França. Três experimentos foram conduzidos em campo no ciclo de cultivo 2003/2004, em diferentes ecossistemas do Planalto Serrano Catarinense. As avaliações de resistência constaram da estimativa de danos causados pelos insetos e da severidade de doenças foliares. No conjunto de todas as avaliações, os acessos - genótipos introduzidos - EEL_10 (Salix nigra, EEL_08 (Salix sp., EEL_02 (Salix x rubens, EEL_13 (Salix sp., EEL_09 (Salix alba, e EEL_20 (Salix sp. foram os mais resistentes ao ataque de pragas e doenças. Dada a reação diferenciada dos acessos quanto ao ataque de doenças e pragas, as próximas ações de pesquisa devem proceder aos testes de artesanato para verificar a sua adequação à demanda para confecção de peças finas.

Willow wood production on radionuclide polluted areas

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Rodkin Oleg I.

2010-01-01

Full Text Available ABSTRACT: One of the key environmental problems in Belarus is effective use of agricultural lands contaminated by radionuclide due to the Chernobyl disaster. The alternative method to traditional agricultural crops is fast growing willow cultivation. It is possible to use biomass of willow as renewable energy source. The goal of our investigation was the estimation of environmental aspects of willow wood production on polluted areas. The field study experiments (2007-2010 were conducted at Krichev district of Mogilev region in eastern Belarus. This region characterized by high level of Cs-137 contamination as well as high level of heavy metals pollution. In the first stage of experiments, the concentration of cesium-137 in different parts of willow biomass had been measured and transfer factor calculated. The measuring had been done for leaves, roots, and wood. To control cesium-137 accumulation in willow biomass we apply different types (nitrogen N, phosphorus P and potassium K and dose of fertilizer. The experiments show that potassium mineral fertilizer is the key factor for radionuclide accumulation control. The optimal dose of potassium is 90 kg per hectare. On the base of experimental results the model of cesium-137 accumulation in the wood for a 21 year has been developed. In accordance with calculation to the end of willow cultivation (21 year concentration of cesium-137 in wood will not be higher than permitted even with the level of cesium-137 contamination in the soil 1480 kBq/m2 (maximum 140 kqB/m2 with permitted level for firewood is 740 Bq/kg.. The concentration of cesium-137 in the roots increases gradually and get maximum in 21 year (3000 kqB/m2. Our results confirm that in the sum about 0.8 million hectares of radionuclide polluted arable lands partly excluded from agricultural practice in Belarus could be used for willow biomass production.

Willow growing - Methods of calculation and profitability

International Nuclear Information System (INIS)

Rosenqvist, H.

1997-01-01

The calculation method presented here makes it possible to conduct profitability comparisons between annual and perennial crops and in addition take the planning situation into account. The method applied is a modified total step calculation. The difference between a traditional total step calculation and the modified version is the way in which payments and disbursements are taken into account over a period of several years. This is achieved by combining the present value method and the annuity method. The choice of interest rate has great bearing on the result in perennial calculations. The various components influencing the interest rate are analysed and factors relating to the establishment of the interest rate in different situations are described. The risk factor can be an important variable component of the interest rate calculation. Risk is also addressed from an approach in accordance with portfolio theory. The application of the methods sheds light on the profitability of Salix cultivation from the viewpoint of business economics, and also how different factors influence the profitability of Salix cultivation. Aspects studied are harvesting intervals, the importance of yield level, the competitiveness of Salix versus grain cultivation, the influence of income taxes on profitability etc. Methods for evaluation of activities concerning cultivation of a perennial crop are described and also involve the application of nitrogen fertilization to Salix cultivation. Studies have been performed using these methods to look into nitrogen fertilizer profitability in Salix cultivation during the first rotation period. Nitrogen fertilizer profitability has been investigated involving both production functions and cost calculations, taking the year fertilization into consideration. 72 refs., 2 figs., 52 tabs

Biomass production in willows. What did we know before the energy crisis

Energy Technology Data Exchange (ETDEWEB)

Perttu, K L [ed.

1984-12-01

The biological foundations of biomass with willows originate in the experiences from basket willow husbandry. This was an established discipline in Europe in the 18th century. Problems concerning site preparation, selection of clones, planting as cuttings, spacing, weed control, rotation time, harvesting and coppicing vigour with respect to the longevity of the stand, were practically solved at the research level and already in practice. The yield potential of basket willow and willows for hoop production as well as yield figures from field experiments were quite high also according to present-day biomass willow experiments. An explanation of this could be the much higher stand densities than has been customary in current willow experiments. Although many practical questions got their answers in basket willow husbandry, open questions still remain. The basket willow era gave only little experience on willow production in peatlands; actually peatsoils were almost avoided. Knowledge of nutrient require ments and fertilization was also rather elementary. These aspects must therefore be established for biomass production. Control of weeds in the establishment phase of the willow husbandry was solved by manual work. Since this is a labour intensive method which is no longer possible, a more modern weed control needs to be developed for current husbandry. As a whole it is a task for related research to attach proper optimization of cultural techniques to suitable willow clones in order to attain and maintain as high a production level as was the case in the old basket willow husbandry. With 25 refs.

Genetics of phenotypic plasticity and biomass traits in hybrid willows across contrasting environments and years.

Science.gov (United States)

Berlin, Sofia; Hallingbäck, Henrik R; Beyer, Friderike; Nordh, Nils-Erik; Weih, Martin; Rönnberg-Wästljung, Ann-Christin

2017-07-01

Phenotypic plasticity can affect the geographical distribution of taxa and greatly impact the productivity of crops across contrasting and variable environments. The main objectives of this study were to identify genotype-phenotype associations in key biomass and phenology traits and the strength of phenotypic plasticity of these traits in a short-rotation coppice willow population across multiple years and contrasting environments to facilitate marker-assisted selection for these traits. A hybrid Salix viminalis  × ( S. viminalis × Salix schwerinii ) population with 463 individuals was clonally propagated and planted in three common garden experiments comprising one climatic contrast between Sweden and Italy and one water availability contrast in Italy. Several key phenotypic traits were measured and phenotypic plasticity was estimated as the trait value difference between experiments. Quantitative trait locus (QTL) mapping analyses were conducted using a dense linkage map and phenotypic effects of S. schwerinii haplotypes derived from detected QTL were assessed. Across the climatic contrast, clone predictor correlations for biomass traits were low and few common biomass QTL were detected. This indicates that the genetic regulation of biomass traits was sensitive to environmental variation. Biomass QTL were, however, frequently shared across years and across the water availability contrast. Phenology QTL were generally shared between all experiments. Substantial phenotypic plasticity was found among the hybrid offspring, that to a large extent had a genetic origin. Individuals carrying influential S. schwerinii haplotypes generally performed well in Sweden but less well in Italy in terms of biomass production. The results indicate that specific genetic elements of S. schwerinii are more suited to Swedish conditions than to those of Italy. Therefore, selection should preferably be conducted separately for such environments in order to maximize biomass

Bioenergy from willow. 1995 Annual report, November 1987--December 1995

Energy Technology Data Exchange (ETDEWEB)

White, E.H.; Abrahamson, L.P.

1997-07-01

Experiments were established at Tully, New York, by the State University of New York College of Environmental Science and Forestry, in cooperation with the University of Toronto and the Ontario Ministry of Natural Resources, to assess the potential of willows for wood biomass production. Specific objectives included determining the effects of clone type, fertilization, spacing, cutting cycle, and irrigation on biomass production. Production was high, with willow clone SV1 yielding nearly 32 oven dry tons per acre (odt ac{sup -1}) with three-year harvest cycle, irrigation, and fertilization. Clone type, fertilization, spacing, cutting cycle, and irrigation all significantly affected biomass production. Willow clone-site trials planted at Massena, and Tully, NY in 1993 grew well during 1994 and 1995, but some clones in the Massena trial were severely damaged by deer browse. Several new cooperators joined the project, broadening the funding base, and enabling establishment of additional willow plantings. Willow clone-site trials were planted at Himrod, King Ferry, Somerset, and Tully, NY, during 1995. A willow cutting orchard was planted during 1995 at the NYS Department of Environmental Conservation Saratoga Tree Nursery in Saratoga, NY. Plans are to begin site preparation for a 100+ acre willow bioenergy demonstration farm in central New York, and additional clone-site trials, in 1996.

Willow bioenergy plantation research in the Northeast

Energy Technology Data Exchange (ETDEWEB)

White, E.H.; Abrahamson, L.P.; Kopp, R.F. [SUNY College of Environmental Science and Forestry, Syracuse, NY (United States); Nowak, C.A. [USDA Forest Service, Warren, PA (United States)

1993-12-31

Experiments were established in Central New York in the spring of 1987 to evaluate the potential of Salix for biomass production in bioenergy plantations. Emphasis of the research was on developing and refining establishment, tending and maintenance techniques, with complimentary study of breeding, coppice physiology, pests, nutrient use and bioconversion to energy products. Current yields utilizing salix clones developed in cooperation with the University of Toronto in short-rotation intensive culture bioenergy plantations in the Northeast approximate 8 oven dry tons per acre per year with annual harvesting. Successful clones have been identified and culture techniques refined. The results are now being integrated to establish a 100 acre Salix large-scale bioenergy farm to demonstrate current successful biomass production technology and to provide plantations of sufficient size to test harvesters; adequately assess economics of the systems; and provide large quantities of uniform biomass for pilot-scale conversion facilities.

Novel Field Data on Phytoextraction: Pre-Cultivation With Salix Reduces Cadmium in Wheat Grains.

Science.gov (United States)

Greger, Maria; Landberg, Tommy

2015-01-01

Cadmium (Cd) is a health hazard, and up to 43% of human Cd intake comes from wheat products, since Cd accumulates in wheat grains. Salix spp. are high-accumulators of Cd and is suggested for Cd phytoextraction from agricultural soils. We demonstrate, in field, that Salix viminalis can remove Cd from agricultural soils and thereby reduce Cd accumulation in grains of wheat subsequently grown in a Salix-treated field. Four years of Salix cultivation reduce Cd concentration in the soil by up to 27% and in grains of the post-cultivated wheat by up to 33%. The higher the plant density of the Salix, the greater the Cd removal from the soil and the lower the Cd concentration in the grains of post-cultivated wheat, the Cd reduction remaining stable several years after Salix cultivation. The effect occurred in both sandy and clayey soil and in winter and spring bread wheat cultivars. Already one year of Salix cultivation significantly decrease Cd in post grown wheat grains. With this field experiment we have demonstrated that phytoextraction can reduce accumulation of a pollutant in post-cultivated wheat and that phytoextraction has no other observed effect on post-cultivated crops than reduced uptake of the removed pollutant.

Salix purpurea Stimulates the Expression of Specific Bacterial Xenobiotic Degradation Genes in a Soil Contaminated with Hydrocarbons.

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Antoine P Pagé

Full Text Available The objectives of this study were to uncover Salix purpurea-microbe xenobiotic degradation systems that could be harnessed in rhizoremediation, and to identify microorganisms that are likely involved in these partnerships. To do so, we tested S. purpurea's ability to stimulate the expression of 10 marker microbial oxygenase genes in a soil contaminated with hydrocarbons. In what appeared to be a detoxification rhizosphere effect, transcripts encoding for alkane 1-monooxygenases, cytochrome P450 monooxygenases, laccase/polyphenol oxidases, and biphenyl 2,3-dioxygenase small subunits were significantly more abundant in the vicinity of the plant's roots than in bulk soil. This gene expression induction is consistent with willows' known rhizoremediation capabilities, and suggests the existence of S. purpurea-microbe systems that target many organic contaminants of interest (i.e. C4-C16 alkanes, fluoranthene, anthracene, benzo(apyrene, biphenyl, polychlorinated biphenyls. An enhanced expression of the 4 genes was also observed within the bacterial orders Actinomycetales, Rhodospirillales, Burkholderiales, Alteromonadales, Solirubrobacterales, Caulobacterales, and Rhizobiales, which suggest that members of these taxa are active participants in the exposed partnerships. Although the expression of the other 6 marker genes did not appear to be stimulated by the plant at the community level, signs of additional systems that rest on their expression by members of the orders Solirubrobacterales, Sphingomonadales, Actinomycetales, and Sphingobacteriales were observed. Our study presents the first transcriptomics-based identification of microbes whose xenobiotic degradation activity in soil appears stimulated by a plant. It paints a portrait that contrasts with the current views on these consortia's composition, and opens the door for the development of laboratory test models geared towards the identification of root exudate characteristics that limit the

Environmental influence of willow coppice systems on farm land

International Nuclear Information System (INIS)

Ledin, S.

1997-01-01

As for all cultivated crops, there are numerous environmental influences when growing willows. These influences are connected with additions to the soil, management measures and changes caused by the developing crop. As a perennial crop with good root penetration into the soil, high water use and efficient nutrient uptake over a long growing season, short rotation forests with willows have an influence on the environment that differs from the influence of annual farm crops. Also the landscape is affected differently by the dense willow stand with a height of seven meters before harvest. There is usually less use of herbicides in the perennial woody crop. Due to larger amounts of litter from the willow plantation and no tillage, there is with time an increase of the humus content in the soil. In relation to this, the soil fauna, using organic material for food, prosper in the short rotation forest. Considerably more cadmium is taken up by the willows than by conventional annual crops. This could be used to clean the soil of cadmium, but more knowledge is needed for the optimisation of this procedure. Willows are usually efficient in taking up nutrients, including nitrogen, but when used as vegetation filters it is important to assess the actual ability of a stand to take up N. This ability varies considerably with the development stage of the plantation and also with site conditions. (au) 30 refs

Genetic variation for characters of importance for growth in Salix viminalis L. Final report; Genetisk variation foer karaktaerer av betydelse foer tillvaext hos Salix viminalis L. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Roennberg-Waestljung, Ann Christin; Gullberg, Urban [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Plant Biology

2000-04-01

The overall goal for this project was to study the genetic variation and the genetic relationships for different growth characters and for water use efficiency (WUE) in Salix viminalis and also to use this knowledge to formulate breeding goals for Salix. Two factorial crossings with Swedish and Polish origin, each with 320 families have been used. Part of the Polish material was used to study the genetic variation for carbon isotope quota. Carbon isotope quota gives a measure of the WUE for the plant. Crossings have been made to change and improve the WUE in Salix viminalis. Construction of a genetic linkage map has started and the map can be used to identify genetic markers for WUE. The results show that most of the growth characters have both additive genetic variation and also a high degree of dominance genetic variation. A strategy in the breeding where both additive and dominance variation can be utilized should be adopted. WUE show mainly additive genetic variation but also a high heritability. This gives great opportunities to improve Salix material for WUE through recurrent selection.

Effects of contaminated soil on the growth performance of young Salix (Salix schwerinii E. L. Wolf) and the potential for phytoremediation of heavy metals.

Science.gov (United States)

Salam, Mir Md Abdus; Kaipiainen, Erik; Mohsin, Muhammad; Villa, Aki; Kuittinen, Suvi; Pulkkinen, Pertti; Pelkonen, Paavo; Mehtätalo, Lauri; Pappinen, Ari

2016-12-01

Salix schwerinii was tested in a pot experiment to assess plant growth performance i.e., relative height and dry biomass and the potential for heavy metal uptake in soils polluted with chromium, zinc, copper, nickel and total petroleum hydrocarbons. The soil used in the pot experiment was collected from a landfill area in Finland. Peat soil was added at different quantities to the polluted soil to stimulate plant growth. The plants were irrigated with tap water or processed water (municipal waste water) to further investigate the effects of nutrient loading on plant biomass growth. The soil was treated at two pH levels (4 and 6). The results showed that the addition of 40-70% peat soil at pH 6 to a polluted soil, and irrigation with processed water accelerated plant growth and phytoextraction efficiency. In the pot experiment, Salix grown in chromium, zinc, copper, nickel and total petroleum hydrocarbons -contaminated field soil for 141 days were unaffected by the contaminated soil and took up excess nutrients from the soil and water. Total mean chromium concentration in the plant organs ranged from 17.05 to 250.45 mg kg -1 , mean zinc concentration ranged from 142.32 to 1616.59 mg kg -1 , mean copper concentration ranged from 12.11 to 223.74 mg kg -1 and mean nickel concentration ranged from 10.11 to 75.90 mg kg -1 . Mean chromium concentration in the plant organs ranged from 46 to 94%, mean zinc concentration ranged from 44 to 76%, mean copper concentration ranged from 19 to 54% and mean nickel concentration ranged from 8 to 21% across all treatments. Under the different treatments, chromium was taken up by Salix in the largest quantities, followed by zinc, copper and nickel respectively. Salix also produced a moderate reduction in total petroleum total petroleum hydrocarbons in the polluted soil. The results from the pot experiment suggest that Salix schwerinii has the potential to accumulate significant amounts of chromium, zinc, copper and nickel

Carbon isotope variation in shrub willow (Salix spp.) ring-wood as an indicator of long-term water status, growth and survival

International Nuclear Information System (INIS)

Schifman, Laura A.; Stella, John C.; Volk, Timothy A.; Teece, Mark A.

2012-01-01

Quantifying interannual change in water status of woody plants using stable carbon isotopes provides insight on long-term plant ecophysiology and potential success in variable environments, including under-utilized agricultural land for biomass production and highly disturbed sites for phytoremediation applications. We analyzed δ 13 C values in annual ring-wood of four shrub willow varieties used for biomass production and phytoremediation at three sites in central New York State (U.S.A). We tested a cost-effective sampling method for estimating whole-shrub water status by comparing δ 13 C values of the plant’s largest stem against a composite sample of all stems. The largest stem showed 0.3‰ 13 C enrichment (range −0.7–1.1‰) compared to the whole-plant, making it a more sensitive indicator of water status than the composite sample. Growing season precipitation exerted a strong negative influence on wood tissue chemistry, with an average 0.26‰ 13 C depletion per 100 mm increase in precipitation. An average annual 0.28‰ 13 C enrichment was also observed with increased plant age; this pattern was consistent among all four willow varieties and across sites. Finally, increased 13 C enrichment in wood tissue was positively associated with plant size at the individual plant level, and associated negatively and more variably survival at the plot scale. These results have important implications for the design and management of biomass production and phytoremediation systems. Increased sensitivity of older plants suggests that longer rotations may experience growth limitations and/or lower survival in low-precipitation years, resulting in reduced yields of biomass crops and loss of effectiveness in phytoremediation applications. -- Highlights: ► A 0.26‰ 13 C depletion in wood tissue occurred per 100 mm increase in precipitation. ► There was an average 13 C enrichment with plant age and size for all varieties. ► Greater 13 C enrichment often lead to

Performance of Salix viminalis and Populus nigra x Populus maximowiczii in short rotation intensive culture under high irrigation

Energy Technology Data Exchange (ETDEWEB)

Fillion, Maud; Brisson, Jacques [Departement de Sciences biologiques, Universite de Montreal, C.P. 6128, succ. Centre-ville, Montreal, Quebec (Canada); Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Teodorescu, Traian I.; Labrecque, Michel [Institut de recherche en biologie vegetale, 4101 Sherbrooke East, Montreal, Quebec (Canada); Sauve, Sebastien [Departement de chimie, Universite de Montreal, C.P. 6128, succursale Centre-ville, Montreal, Quebec (Canada)

2009-09-15

On a plantation established in 2004 from stem cuttings at a density of 20,000 trees per hectare, we investigated growth and nutritional plant response to a high hydraulic regime for two species (Salix viminalis and Populus nigra x Populus maximowiczii), using a comparative approach with measurements from irrigated and control plots. The plantation was irrigated from June to September 2005 with about 140 mm per day. The equivalent of 120 Kg NO{sub 3}-N, 40 Kg P{sub 2}O{sub 5}-P and 85 Kg K{sub 2}O-K per hectare per year was applied by means of irrigation with wastewater. No mortality occurred and stem biomass production of both poplar and willow species were not statistically different on irrigated and control areas. However, S. viminalis revealed to be more tolerant to flooded conditions since these corresponded more closely to its nutritional requirements (foliar concentration of 20 mgN g{sup -1}). The capacity of S. viminalis to withstand waterlogged conditions could play an important role in the sustainability of a plantation for the filtration of effluent at low pollutant concentration. (author)

78 FR 41499 - Endangered and Threatened Wildlife and Plants; Threatened Status for the Northern Mexican...

Science.gov (United States)

2013-07-10

...), willows (Salix ssp.), canyon grape (Vitis arizonica), blackberry (Rubus ssp.), Arizona sycamore (Platanus... (Quercus gambelii), and ponderosa pine (Pinus ponderosa) (Rosen and Schwalbe 1988, pp. 34- 35). Rosen and...

Phytoremediation potential of willow tress for aquifers contaminated with ethanol-blended gasoline

Energy Technology Data Exchange (ETDEWEB)

Corseuil, H.X. [Universidade Federal de Santa Catarina, Florianopolis (Brazil). Departamento de Engenharia Sanitaria e Ambiental; Moreno, F.N. [Universidade do Sul de Santa Catarina, Palhoca (Brazil). Centro de Ciencias Agrarias e das Engenharias

2001-07-01

Ethanol-blended gasoline has been used in Brazil for 20 years and, probably, is going to be more widely used in North America due to the MtBE environmental effects on groundwater. The potential impacts caused by the presence of ethanol in UST spills are related to the co-solvency effect and the preferential degradation of ethanol over the BTEX compounds. These interactions may increase the length of dissolved hydrocarbon plumes and the costs associated with site remediation. This study investigates the advantages of phytoremediation to overcome the problems associated with the presence of ethanol in groundwater contaminated with gasoline-ethanol mixtures. Experiments were performed under lab conditions with cuttings of Willow tree (Salix babylonica) cultivated hydroponically. Results showed that the cuttings were able to reduce ethanol and benzene concentrations by more than 99% in less than a week. The uptake of both contaminants was confirmed by blank controls and was significantly related to cuttings transpiration capacity. Sorption onto roots biomass also markedly affected the behavior of contaminants in solution. Experiments to evaluate plants' toxicity to ethanol indicated that plants were only affected when aqueous ethanol concentration reached 2000mgl{sup -1}. Results suggest that phytoremediation can be a good complement to intrinsic remediation in shallow aquifer sites contaminated with ethanol-blended gasoline spills. (Author)

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.

Status, ecology, and conservation of the southwestern willow flycatcher

Science.gov (United States)

Deborah M. Finch; Scott H. Stoleson

2000-01-01

This publication was prepared in response to a need expressed by southwestern agencies and organizations for a comprehensive assessment of the population status, history, biology, ecology, habitats, threats, and conservation of the southwestern willow flycatcher (Empidonax traillii extimus). The southwestern willow flycatcher was federally listed as...

Biological diversity of Salix taxa in Cu, Pb and Zn phytoextraction from soil.

Science.gov (United States)

Mleczek, Mirosław; Rutkowski, Paweł; Goliński, Piotr; Kaczmarek, Zygmunt; Szentner, Kinga; Waliszewska, Bogusława; Stolarski, Mariusz; Szczukowski, Stefan

2017-02-01

The aim of the study was to estimate the efficiency of copper (Cu), lead (Pb) and zinc (Zn) phytoextraction by 145 Salix taxa cultivated in an area affected by industrial activity. Survivability and biomass of plants were also analyzed. The highest Cu, Pb and Zn content in shoots was 33.38 ± 2.91 (S. purpurea × viminalis 8), 24.64 ± 1.97 (S. fragilis 1) and 58.99 ± 4.30 (S. eriocephala 7) mg kg -1 dry weight, respectively. In the case of unwashed leaves, the highest content of these metals was 135.06 ± 8.14 (S. purpurea 26), 67.98 ± 5.27 (S. purpurea 45) and 142.56 ± 12.69 (S. alba × triandra 2) mg kg -1 dw, while in washed leaves it was 106.02 ± 11.12 (S. purpurea 45), 55.06 ± 5.75 (S. purpurea 45) and 122.87 ± 12.33 (S. alba × triandra 2) mg kg -1 dw, respectively. The differences between the highest and lowest values for Cu, Pb and Zn were 545%, 20500% and 535% in shoots; 2692%, 2560% and 7500% in unwashed leaves; and 3286%, 2221% and 6950% in washed leaves, respectively. S. acutifolia was able to effectively accumulate all three metals jointly, producing shoots that were well developed in both length and diameter when compared with the other tested willows-an ability that would suggest its high suitability for practical application.

Local variability in growth and reproduction of Salix arctica in the High Arctic

Directory of Open Access Journals (Sweden)

Noémie Boulanger-Lapointe

2016-06-01

Full Text Available Arctic terrestrial ecosystems are heterogeneous because of the strong influences of microtopography, soil moisture and snow accumulation on vegetation distribution. The interaction between local biotic and abiotic factors and global climate patterns will influence species responses to climate change. Salix arctica (Arctic willow is a structuring species, ubiquitous and widespread, and as such is one of the most important shrub species in the High Arctic. In this study, we measured S. arctica reproductive effort, early establishment, survival and growth in the Zackenberg valley, north-east Greenland. We sampled four plant communities that varied with respect to snow conditions, soil moisture, nutrient content and plant composition. We found large variability in reproductive effort and success with total catkin density ranging from 0.6 to 66 catkins/m2 and seedling density from <1 to 101 seedlings/m2. There were also major differences in crown area increment (4–23 cm2/year and stem radial growth (40–74 µm/year. The snowbed community, which experienced a recent reduction in snow cover, supported young populations with high reproductive effort, establishment and growth. Soil nutrient content and herbivore activity apparently did not strongly constrain plant reproduction and growth, but competition by Cassiope tetragona and low soil moisture may inhibit performance. Our results show that local environmental factors, such as snow accumulation, have a significant impact on tundra plant response to climate change and will affect the understanding of regional vegetation response to climate change.

Improving the water use efficiency of short rotation coppice (SRC) willows

Energy Technology Data Exchange (ETDEWEB)

Stephens, W.; Bonneau, L.; Groves, S.; Armstrong, A.; Lindegard, K.

2003-07-01

On the premise that biofuels will make a significant contribution to the UK's renewable energy sources by the year 2010, willow short rotation coppicing is being studied. The high water requirement of willow is seen as a potential problem in the drier regions of the UK and increasing the water use efficiency and/or draught resistance would extend the areas where willow coppicing would be profitable. The first part of the project was to investigate the water use of a number of near-market varieties of willow and evaluate techniques for early drought tolerance screening in a breeding program and for this, field studies were conducted. This report gives some very early results from the preliminary study. Since DTI funding ceased before the one-season study of the three-year program was complete, the results should be regarded as tentative only. The next phase of the program will be funded by DEFRA and will include efforts to identify how a range of high-yielding willows respond to water stress.

Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae

Directory of Open Access Journals (Sweden)

Carromberth Carioca Fernandes

2009-01-01

Full Text Available Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas, of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin, were determined through analyses of NMR 1D (¹H and 13C and NMR 2D (gHSQC and gHMBC. These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae. The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active.

Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae); Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae)

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Carromberth Carioca [Universidade Federal do Acre (UFAC), Rio Branco, AC (Brazil). Centro de Ciencias Biologicas e da Natureza; Cursino, Lorena Mayara de Carvalho; Novaes, Jussival de Abreu Pinheiro; Demetrio, Camilla Avelino; Pereira Junior, Orlando Liborio; Nunez, Cecilia Veronica [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Produtos Naturais; Amaral, Ieda Leao do [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Botanica

2009-07-01

Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas), of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin), were determined through analyses of NMR 1D ({sup 1}H and {sup 13}C) and NMR 2D (gHSQC and gHMBC). These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae). The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active. (author)

Coastal Energy Corporation, Willow Springs, MO

Science.gov (United States)

notice of a proposed Administrative Penalty Assessment against Coastal Energy Corporation, located at 232 Burnham Road, Willow Springs, Missouri, for alleged violations at the facility located at or near that facility.

Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis

Directory of Open Access Journals (Sweden)

Y. Zhou

2013-07-01

Full Text Available During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana and poplar (Populus simonii, bushes (salix – Salix psammophila, and agricultural crops (maize – Zea mays, depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes should be used to vegetate sand dunes.

Pelletizing using forest fuels and Salix as raw materials. A study of the pelletizing properties; Pelletering med skogsbraensle och Salix som raavara. En undersoekning av pelleterbarheten

Energy Technology Data Exchange (ETDEWEB)

Martinsson, Lars; Oesterberg, Stefan [Swedish National Testing and Research Inst., Boraas (Sweden)

2004-08-01

Three common forest fuels: light thinning material, cull tree and logging residues as well as energy forest fuel (Salix) has been used as fuel pellet materials. Logging residues and Salix were stacked for approximately 6 and 10 months respectively. Parameters varied for each raw material have been the moisture content and the press length of the die. These parameters have been changed to obtain best possible quality, mainly concerning mechanical durability. Pellets were also produced from bark free shavings in order to use as a reference in this study. Physical as well as chemical properties have been compared. It was comparatively easy to press logging residues and Salix into durable pellets and, even with larger press length, the production of pellets was higher than it was for the other raw materials. The density was equal for all pellets while the mechanical durability was better for all tested raw materials compared with the reference material. The fact that all raw materials besides the reference material contains bark which has an improving effect on the degree of hardness. The quality properties were mainly about the same or better for pellets made of light thinning material and cull tree respectively, compared with the reference pellets. However, the ash content was approximately twice as high compared with the reference pellets. The pellets made of logging residues and Salix respectively were of very good quality concerning duration and density but the ash content was approximately 10 times higher than in the reference pellets. Additionally, the nitrogen content was 6-9 times higher compared with the reference pellets.

Fertilization of SRC willow. II

DEFF Research Database (Denmark)

Sevel, L; Ingerslev, Morten; Nord-Larsen, Thomas

2014-01-01

impacts of different doses of mineral fertilizer, manure and sewage sludge in a commercially grown SRC willow stand. We examined macro nutrient and heavy metal leaching rates and calculated element balances to evaluate the environmental impact. Growth responses were reported in a former paper (Sevel et al...

Tree and shrub expansion over the past 34 years at the tree-line near Abisko, Sweden.

Science.gov (United States)

Rundqvist, Sara; Hedenås, Henrik; Sandström, Anneli; Emanuelsson, Urban; Eriksson, Håkan; Jonasson, Christer; Callaghan, Terry V

2011-09-01

Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic Sweden. We recorded the change in coverage of shrub and tree species over a 32- to 34-year period, in three 50 x 50 m plots; in the alpine-tree-line ecotone. The cover of shrubs and trees (tree stems (> or =3.5 cm) were noted and positions determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory.

Earthworm short-term response to dairy wastewater applied to a Salix plantation

DEFF Research Database (Denmark)

Krogh, Paul Henning; Jørgensen, Uffe; Berg Olsen, Anne

Odour is one problem in the management of waste water from dairy, thus the organic Thise Dairy has developed an all year round solution releasing the waste water into underground tubes at 30 cm depth in a willow energy crop plantation established in 2013. The wastewater contains 0.3% dry matter...... in the untreated control willow area, were established in Oct. 2017 and considered (non-randomized) blocks. In other words this was a Before-After-Control-Impact (BACI) design. Plots were sampled to estimate earthworm abundance one week before and one week after treatment (map link: goo.gl/tvvMuF). The willow...... was surrounded by an agricultural field with a history of wastewater fertilisation subject to an exploratory sampling. - We found seven species of earthworms in the willow and five in the agricultural soil. Juveniles of A. tuberculata, A. caliginosa, L. herculeus, L. castaneus, are morphologically intrageneric...

Demonstration cultivation of Salix in northern Sweden with a focus on frost resistance; Demonstrationsodling av Salix i Norrland med frosttolerans i fokus

Energy Technology Data Exchange (ETDEWEB)

Soederstroem, Yvonne

2010-06-15

This project is part of the Thermal Engineering Research Association's (Vaermeforsk) programme 'Crops from field to energy production' and the goal is to convince growers to begin cultivating Salix in the northern part of Sweden. The project will demonstrate whether it is possible to grow Salix and examine what type of Salix (the report refers to the different types as Tora, Karin and Gudrun) is most frost-resistant and resistant to insects, fungal infections and animals. The project is aimed primarily at landowners and energy companies. The results showed that growth at the demonstration plots was moderate and the establishment rate was considered good. Growth has been uneven across the fields. At Eriksgaard, about 75% of the plants survived the winter. Survival was determined by the number of plants missing and dead. Additional plants were planted at the sites in 2009. No major insect or leaf fungus attacks were noted at either Eriksgaard or Soergaard, but they both experienced grazing from deer and elk. The rating showed that the herbicide treatment was not sufficient on the demonstration fields. For this reason, a comparison of average lengths was performed of Gudrun in Bodum, where the weeds had not grown as much. The comparison showed that the difference in growth was not significant in the autumn 2008, but the plants in Bodum had grown more by autumn 2009. Topping was not performed in the spring 2009 so that the plants would have an opportunity to grow higher than the weeds and the plants would have an opportunity to have a growth spurt. A comparison of Tora, Karin and Gudrun in Roedoen showed moderate growth for the three types. There were variations in the rows and across the field, mostly for Tora and Karin. Gudrun had lower, but more consistent growth across the field. During the summer 2009, survival was rated for the plants in Roedoen. This rating showed that 90% of Tora, 60% of Karin and 70% of Gudrun had survived the winter. The Salix

Cryopreservation of Populus trichocarpa and Salix dormant buds with recovery by grafting or direct rooting.

Science.gov (United States)

Bonnart, Remi; Waddell, John; Haiby, Kathy; Widrlenchner, Mark P; Volk, Gayle M

2014-01-01

Methods are needed for the conservation of clonally maintained trees of Populus and Salix. In this work, Populus trichocarpa and Salix genetic resources were cryopreserved using dormant scions as the source explant. We quantified the recovery of cryopreserved materials that originated from diverse field environments by using either direct sprouting or grafting. Scions (either at their original moisture content of 48 to 60% or dried to 30%) were slowly cooled to -35 degree C, transferred to the vapor phase of liquid nitrogen (LNV, -160 degree C), and warmed before determining survival. Dormant buds from P. trichocarpa clones from Westport and Boardman, OR had regrowth levels between 42 and 100%. Direct rooting of cryopreserved P. trichocarpa was also possible. Ten of 11 cryopreserved Salix accessions, representing 10 different species, exhibited at least 40% bud growth and rooting after 6 weeks when a bottom-heated rooting system was implemented. We demonstrate that dormant buds of P. trichocarpa and Salix accessions can be cryopreserved and successfully regenerated without the use of tissue culture.

Mycorrhizal symbioses of Salix repens : diversity and functional significance

NARCIS (Netherlands)

Heijden, van der E.W.

2000-01-01

This thesis investigates the significance of different mycorrhizal fungi, belonging to different functional types (arbuscular mycorrhiza-AM and ectomycorrhiza-EcM), in Salix repens . A comparison between above-ground and below-ground observations on ectomycorrhizal

Phytopharmacology and medicinal properties of Salix aegyptiaca L.

African Journals Online (AJOL)

enoh

2012-04-05

Apr 5, 2012 ... The anti-inflammatory and antinociceptive properties of extracts of Salix family ... Iranian people for its calming effect on heart and possibly its antihypertensive .... cancer, Alzheimer's disease, Parkinson's disease and even in aging ... with patient's normal activity and are often difficult to stop once the therapy ...

White dwarf-red dwarf binaries in the Galaxy

NARCIS (Netherlands)

Besselaar, E.J.M. van den

2007-01-01

This PhD thesis shows several studies on white dwarf - red dwarf binaries. White dwarfs are the end products of most stars and red dwarfs are normal hydrogen burning low-mass stars. White dwarf - red dwarf binaries are both blue (white dwarf) and red (red dwarf). Together with the fact that they are

Uptake, metabolism, accumulation and toxicity of cyanide in willow trees

DEFF Research Database (Denmark)

Larsen, Morten; Ucisik, Ahmed Süheyl; Trapp, Stefan

2005-01-01

Chemicals taken up into plants may be accumulated so leading to toxic effects. Uptake and phytotoxicity of free cyanide was determined with the willow-tree transpiration test. Willow sets were grown in sand and irrigated with varying levels of cyanide (CN). Toxicity was determined by measuring...... transpiration. At CN concentrations below 10 mg/L, no toxic effects were observed. At 20 mg/L, transpiration was reduced to approximately 50% after 96 h. With 30, 40 and 50 mg/L, the transpiration decreased with a similar rate to cyanide in plant...... tissue was observed at 40 and 50 mg/L. The kinetics of metabolism of cyanide by roots, stems and leaves of willows was determined by the closed-bottle metabolism test. The Michaelis−Menten parameters vmax and KM (maximal metabolic velocity and half-saturation constant, respectively) were determined...

Nutrient enhanced short rotation coppice for biomass in central Wales

Energy Technology Data Exchange (ETDEWEB)

Hodson, R.W.; Slater, F.M.; Lynn, S.F.; Randerson, P.F. [Univ. of Wales (United Kingdom)

1993-12-31

Two projects involving short rotation willow coppice are taking place on the eastern side of the Cambrian Mountains in central Wales. One project examines, as an alternative land use, the potential of short rotation willow coppice variously enhanced by combinations of lime, phosphorous and potassium fertilizers and also digested sewage sludge on an acidic upland site at an altitude of 260m. The first year results of this project are described in detail, showing the necessity for limestone additions and also demonstrating that of the four willow varieties established, Salix dasyclados is the only possible, profitable fuel crop. The other project involving willow in a filter bed system is outlined along with an additional project investigating the effect of sewage sludge additions on the Rubus fruticosus production in a birch dominated mixed deciduous woodland.

Seasonal abundance and development of the Asian longhorned beetle and natural enemy prevalence in different forest types in China

Science.gov (United States)

Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao; Therese M. Poland

2016-01-01

Seasonal abundance and population development of the Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), and prevalence of its natural enemies were studied on Hankow willow (Salix matsudana Koidz.) at an urban forest site (Anci) and a rural forest site (Tangerli) in Hebei province...

Wound-induced proteinase inhibitor in Salix viminalis and its association with defence against insects

Energy Technology Data Exchange (ETDEWEB)

Saarikoski, P. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

1997-09-01

For successful traditional breeding, the plant material has to be screened for genetic variation for the desired traits. By screening Salix clones for wound-induced proteinase inhibitor (PI) activity and ethylene evolution, it was possible to identify variation for both characters among the Salix clones tested. However, no correlation was observed with insect and pathogen resistance. Since there was no simple relationship between wound-induced ethylene production, accumulation of PI and pest resistance, a more systematic investigation of Salix PIs was begun. A gene (swin1.1) encoding a 21 kDa trypsin inhibitor with characteristics of Kunitz-type of PI was sequenced. The trypsin inhibitor encoded by the isolated swin1.1 gene was shown to be functional in vitro and exhibit specificity for trypsin. It is therefore likely that this PI is involved in the plant defence in Salix, since many insects have trypsin as their major digestive protease. In further support of this view, in bio-tests with poplar the mortality of the first instar larvae (Lymantria dispar) was significantly increased, both after application of the trypsin inhibitor encoded by swin1.1 directly on poplar leaves and after feeding the larvae with transgenic poplar over-expressing the swin1.1 gene. In Salix, the swin1.1 gene was shown to be induced by mechanical wounding, insect feeding and by treatment with the signalling substances salicylic and jasmonic acid. The locally wound-induced response (mechanical and insect) was greater than the systemic response. Other swin1 gene family members were also differentially expressed after the inductive treatment. 187 refs., 3 figs., 2 tabs.

Willow trees from heavy metals phytoextraction as energy crops

International Nuclear Information System (INIS)

Šyc, Michal; Pohořelý, Michael; Kameníková, Petra; Habart, Jan; Svoboda, Karel; Punčochář, Miroslav

2012-01-01

Phytoextraction ability of some fast growing plant species leads to the idea of connecting biomass production with soil remediation of contaminated industrial zones and regions. This biomass will contain significant amount of heavy metals and its energetic utilization has to be considered carefully to minimize negative environmental impacts. This study was focused on potential disposal methods of willow trees contaminated by heavy metals (Cd, Cu, Pb, Zn) with the emphasis on energetic utilization of biomass. Composting seems to be suitable pre-treatment method resulting in decrease of heavy metals leachability and biomass weight reduction. The possibility of willow trees application for energetic purposes was investigated and consequently incineration tests of willow trees samples in fluidized bed reactor were realized. Distribution of selected heavy metals in different ash fractions and treatment methods of produced ashes were studied as well. -- Highlights: ► Composting is an appropriate pre-treatment method for phytoextraction crops. ► Fluidized bed combustion is suitable disposal method of phytoextraction crops. ► Ashes from phytoextraction crops combustion cannot be used as fertilizers.

Erratum to: Fertilization of SRC Willow

DEFF Research Database (Denmark)

Sevel, L; Ingerslev, Morten; Nord-Larsen, Thomas

2014-01-01

impacts of different doses of mineral fertilizer, manure and sewage sludge in a commercially grown SRC willow stand. We examined macro nutrient and heavy metal leaching rates and calculated element balances to evaluate the environmental impact. Growth responses were reported in a former paper (Sevel et al...

Willow Browse Survey 2016 : Biological Summary Report

Data.gov (United States)

Department of the Interior — Browse pressure by ungulate species, primarily elk, is known to have a negative impact on the health of willow stands. On Baca and Alamosa NWR’s, it has been noticed...

Willow Browse Survey 2015 : Biological Summary Report

Data.gov (United States)

Department of the Interior — Browse pressure by ungulate species, primarily elk, is known to have a negative impact on the health of willow stands. On Baca and Alamosa NWR’s, it has been noticed...

Willow as fuel for district heating. Experiences from test combustion; Energipil som braendsel til fjernvarme - Erfaringsindsamling fra testfyringer

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Joergen

2012-10-15

The project has been a study of the fuel characteristics of willow chips. The study was carried out on Trustrup-Lyngby Heating Plant and Assens District Heating Plant in the period 2011-12. Operating experiences were collected from the two plants. Furthermore, yield and crop data were collected from suppliers of willow chips to Assens District Heating Plant, and the analysis of particle size distribution of the willow chips is carried out. The collected data on yield and particle size distribution are compared with results from previous studies. The project has shown that willow chips generally are a suitable and attractive fuel in wood-fired heat and power plants. The plants are very aware of quality of willow chips and want chips with coarse structure. Furthermore, there is the wish that water content of willow chips are on par with the moisture content of wood chips, i.e. around 30-40%; woodchips are the vast majority of the chips used in the plants. Wood chips produced from fresh willow shoots with chopper will typically have a moisture content of 50-60 %. Such ''wet'' chips will of some plants be deselected during winter, where there is a requirement of safe and high boiler output. Other plants will simply mix the ''wet'' willow chips with other, drier types of chips and can use it almost all the year. If the willow shoots are harvested as branches, which subsequently are allowed to dry for a period before chipping, willow chips can be produced with a moisture content that is in line with what is typical in wood chips. Analysis of particle size distribution shows that willow chips harvested with a cutting machine usually can meet the requirements for quality classes ''fine'', ''medium'' and ''coarse''. An account of the harvested yields of willow among the growers who supplied willow chips to Assens Heating Plant, showed a relatively low yield of 5.1 tonnes dry

Late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska

Science.gov (United States)

Ager, T.A.

2003-01-01

Pollen analysis of a sediment core from Zagoskin Lake on St. Michael Island, northeast Bering Sea, provides a history of vegetation and climate for the central Bering land bridge and adjacent western Alaska for the past ???30,000 14C yr B.P. During the late middle Wisconsin interstadial (???30,000-26,000 14C yr B.P.) vegetation was dominated by graminoid-herb tundra with willows (Salix) and minor dwarf birch (Betula nana) and Ericales. During the late Wisconsin glacial interval (26,000-15,000 14C yr B.P.) vegetation was graminoid-herb tundra with willows, but with fewer dwarf birch and Ericales, and more herb types associated with dry habitats and disturbed soils. Grasses (Poaceae) dominated during the peak of this glacial interval. Graminoid-herb tundra suggests that central Beringia had a cold, arid climate from ???30,000 to 15,000 14C yr B.P. Between 15,000 and 13,000 14C yr B.P., birch shrub-Ericales-sedge-moss tundra began to spread rapidly across the land bridge and Alaska. This major vegetation change suggests moister, warmer summer climates and deeper winter snows. A brief invasion of Populus (poplar, aspen) occurred ca. 11,000-9500 14C yr B.P., overlapping with the Younger Dryas interval of dry, cooler(?) climate. During the latest Wisconsin to middle Holocene the Bering land bridge was flooded by rising seas. Alder shrubs (Alnus crispa) colonized the St. Michael Island area ca. 8000 14C yr B.P. Boreal forests dominated by spruce (Picea) spread from interior Alaska into the eastern Norton Sound area in middle Holocene time, but have not spread as far west as St. Michael Island. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Cultural Resources Investigations in the Vicinity of Fort Jackson, Plaquemines Parish, Louisiana: The Proposed Solari Borrow Area

Science.gov (United States)

1989-08-01

tory of flora. Trees such as Virginia live oak (Quercus virginiana), black willow (Salix nigra), hackberry (Celtislaevi- gata), and persimmon ( Diospyros ...bullfrog, is a human food source today and may have been prehistorically as well. The toad, however, of the genus Bufo is not normally consumed

Effects of long-term Salix cultivation on total and plant-available contents of Cadmium in the soil - a pilot study

International Nuclear Information System (INIS)

Eriksson, Jan; Ledin, S.

1996-02-01

The aim of the project was to study how total and plant-available contents of Cadmium in the soil are affected by the large amounts of Cadmium that are removed during the harvesting of Salix. Eight long-term Salix plantations, 8-30 years old, were chosen. At each place soil samples were taken in 4 areas in the stands of Salix and in 4 neighbouring areas with comparable soil conditions, but without Salix (reference areas). Cd in three fractions of different bonding strength were determined in the soil samples. The fractions roughly correspond to the total concentration, the exchangeable fraction, and the fraction dissolved in the soil solution. The result showed a relatively minor effect of the Salix plantation on the total concentrations. In six of eight cases, however, the concentrations tended to be lower in the Salix plantations than in the reference areas. When consideration was given to certain pH differences, the exchangeable, and particularly the most soluble fraction, showed a clear tendency for concentrations to be lower in the Salix stands than in the reference areas.The concentrations in stem samples from growing stands were generally lower than those measured in harvest-mature stems in other studies. The concentrations in foliage were of the same magnitude as those in the stems, implying that there is an important return of Cd to the soil at leaf-fall. The negligible effect on the total content in the soil may depend on uptake occurring both in the topsoil and in the subsoil. Re-circulation via the leaves will also result in redistribution of Cd from the subsoil to the topsoil, compensating the uptake from the topsoil. The conclusion reached was that Salix cultivation results in a reduction of the plant-available Cd in the soil, but the effect is not concentrated to the topsoil. 13 refs, 5 tabs, 4 figs

Nanoscale Phenomena Occurring during Pyrolysis of Salix viminalis Wood

Directory of Open Access Journals (Sweden)

Aleksandra W. Cyganiuk

2013-01-01

Full Text Available Selective utilisation of unique properties of Salix viminalis wood enables preparation of materials of nanotechnologic properties. Thermal decomposition of lignin-cellulose organic matter results in the formation of a nanostructured porous carbon matrix (charcoal. Narrowed pore size distribution (PSD in the subnanometer range allows to consider the charcoals as carbon molecular sieves (CMSs, which are capable of separating even chemically inert gases like neon, krypton, and nitrogen. High tolerance of Salix viminalis to heavy metal ions enables enriching living plant tissues with metal ions like lanthanum and manganese. Such ions may later form LaMnO3 with parallel transformation of plant tissues (organic matter to carbon matrix using a heat treatment. In this way, one gets a hybrid material: a porous carbon matrix with uniformly suspended nanocrystallites of LaMoO3. The crystallites are in the catalytically active phase during the conversion of n-butanol to heptanone-4 with high yield and selectivity.

Puente Willow Creek en Monterrey, California

Directory of Open Access Journals (Sweden)

Editorial, Equipo

1965-09-01

Full Text Available Of the 10 awards given every year by the Prestressed Concrete Institute for the most outstanding prestressed concrete projects, two have been awarded in California this year, one of them to the Willow Creek bridge, near Monterrey. The prestressed, double T girders of this bridge were made at a workshop, a great distance from the bridge site. These are 24 m long, 1.35 m high, and are stabilized by transversal diaphragms, 20 cm in thickness. The table deck is of reinforced concrete, being 8.85 m wide and 20 cm thick. The structure is straightforward, slender, and adapts itself pleasantly to the background. It has seven spans and crosses over a secondary road, in addition to bridging the Willow stream. The supporting piles are hollow, of rectangular cross section, and over them a cross beam carries the five girders and the deck itself. The end abutments consist of vertical reinforced concrete walls, and supporting, soil filled, structures. The above information was supplied by the California Road Department.De los diez premios que anualmente concede el Prestressed Concrete Institute para las obras de hormigón pretensado más notables, dos han correspondido a California y uno de ellos al puente de Willow Creek, situado en la región de Monterrey. Las vigas de hormigón pretensado, con sección en forma de doble T, se prefabricaron en un taller situado a gran distancia del puente. Tienen 24 m de longitud y 1,35 m de canto, estando arriostradas con diafragmas transversales de 20 cm de espesor. La losa del tablero, de hormigón armado, tiene 8,85 m de anchura y 20 cm de espesor. La estructura es sencilla, esbelta y armoniza perfectamente con el paisaje que la circunda. Tiene siete tramos y salva un paso inferior secundario y el arroyo Willow. Los soportes, se apoyan sobre pilotes, algunos de gran altura; son huecos, de sección rectangular y terminan en una cruceta que sirve de sostén a las cinco vigas que soportan la losa del tablero. Los estribos

Evaluation of Populus and Salix continuously irrigated with landfill leachate I. Genotype-specific elemental phytoremediation.

Science.gov (United States)

Zalesny, Ronald S; Bauer, Edmund O

2007-01-01

There is a need for the identification and selection of specific tree genotypes that can sequester elements from contaminated soils, with elevated rates of uptake. We irrigated Populus (DN17, DN182, DN34, NM2, NM6) and Salix (94003, 94012, S287, S566, SX61) genotypes planted in large soil-filled containers with landfill leachate or municipal water and tested for differences in inorganic element concentrations (P, K, Ca, Mg, S, Zn, B, Mn, Fe, Cu, Al, Na, and Cl) in the leaves, stems, and roots. Trees were irrigated with leachate or water during the final 12 wk of the 18-wk study. Genotype-specific uptake existed. For genera, tissue concentrations exhibited four responses. First, Populus had the greatest uptake of P, K, S, Cu, and Cl. Second, Salix exhibited the greatest uptake of Zn, B, Fe, and Al. Third, Salix had greater concentrations of Ca and Mg in leaves, while Populus had greater concentrations in stems and roots. Fourth, Populus had greater concentrations of Mn and Na in leaves and stems, while Salix had greater concentrations in roots. Populus deltoides x P. nigra clones exhibited better overall phytoremediation than the P. nigra x P. maximowiczii genotypes tested. Phytoremediation for S. purpurea clones 94003 and 94012 was generally less than for other Salix genotypes. Overall, concentrations of elements in the leaves, stems, and roots corroborated those in the plant-sciences literature. Uptake was dependent upon the specific genotype for most elements. Our results corroborated the need for further testing and selecting of specific clones for various phytoremediation needs, while providing a baseline for future researchers developing additional studies and resource managers conducting on-site remediation.

Aufnahme von Cyanid in Pflanzen

DEFF Research Database (Denmark)

Trapp, Stefan; Koch, Ines; Christiansen, Helle

2001-01-01

Cyanides are waste products from the pyrolysis of coal and are frequent soil pollutants in cities nowadays. Prussic acid (HCN) is a fast acting, highly toxic poison, but iron-complexed cyanides in soil are far less toxic. The phytotoxicity of free CN to basket willows (Salix viminalis) was determ...

7 CFR 301.51-2 - Regulated articles.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Regulated articles. 301.51-2 Section 301.51-2... Regulated articles. The following are regulated articles: (a) Firewood (all hardwood species), and green... (sycamore), Populus (poplar), Salix (willow), Sorbus (mountain ash), and Ulmus (elm). (b) Any other article...

Machinery management data for willow harvest with a bio-baler

Energy Technology Data Exchange (ETDEWEB)

Savoie, P. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada); Hebert, P.L. [Laval Univ., Quebec City, PQ (Canada). Dept. des sols et de genie agroalimentaire; Robert, F.S. [Laval Univ., Quebec City, PQ (Canada). Sols et environnement

2010-07-01

Willow harvested in 2-to-3-year rotations has been touted as a reliable source of biomass. A newly designed harvester based on a round baler was developed in 2006. The third generation biobaler was evaluated in 2009 at 2 willow plantations in Quebec. The first site at Godmanchester was a three-year old regrowth with an estimated 52,000 stems/ha of large diameter willow. The biobaler with a flail cutter harvested three plots totalling 4,136 m{sup 2}. Total harvested biomass was 10.36 t DM in 42 bales. The harvest rate averaged 29 bale/h with an average bale size of 1.22 m wide by 1.30 m in diameter. Diesel fuel consumption averaged 0.81 L/bale. Measured losses averaged 11 per cent of the yield. The second site at Saint-Roch-del'Achigan was a two-year old growth with an estimated 49,000 stems/ha of large stem willow. The biobaler harvested seven plots totalling 15,740 m{sup 2}. Total harvest was 30.70 t DM in 148 bales. The first 14 bales were harvested with a saw blade header. All other bales were harvested with the flail cutter at a faster rate. Bale density averaged 129 kg DM/m{sup 3}. Fuel consumption averaged 0.72 L/bale. Losses averaged 20 per cent of the yield with the saw blade header.

Life cycle assessment of a willow bioenergy cropping system

International Nuclear Information System (INIS)

Heller, M.C.; Keoleian, G.A.; Volk, Timothy A.

2003-01-01

The environmental performance of willow biomass crop production systems in New York (NY) is analyzed using life cycle assessment (LCA) methodology. The base-case, which represents current practices in NY, produces 55 units of biomass energy per unit of fossil energy consumed over the biomass crop's 23-year lifetime. Inorganic nitrogen fertilizer inputs have a strong influence on overall system performance, accounting for 37% of the non-renewable fossil energy input into the system. Net energy ratio varies from 58 to below 40 as a function of fertilizer application rate, but application rate also has implications on the system nutrient balance. Substituting inorganic N fertilizer with sewage sludge biosolids increases the net energy ratio of the willow biomass crop production system by more than 40%. While CO 2 emitted in combusting dedicated biomass is balanced by CO 2 adsorbed in the growing biomass, production processes contribute to the system's net global warming potential. Taking into account direct and indirect fuel use, N 2 O emissions from applied fertilizer and leaf litter, and carbon sequestration in below ground biomass and soil carbon, the net greenhouse gas emissions total 0.68 g CO 2 eq. MJ biomassproduced -1 . Site specific parameters such as soil carbon sequestration could easily offset these emissions resulting in a net reduction of greenhouse gases. Assuming reasonable biomass transportation distance and energy conversion efficiencies, this study implies that generating electricity from willow biomass crops could produce 11 units of electricity per unit of fossil energy consumed. Results form the LCA support the assertion that willow biomass crops are sustainable from an energy balance perspective and contribute additional environmental benefits

Phytoremediation, a sustainable remediation technology? Conclusions from a case study. I: Energy production and carbon dioxide abatement

International Nuclear Information System (INIS)

Witters, N.; Mendelsohn, R.O.; Van Slycken, S.; Weyens, N.; Schreurs, E.; Meers, E.; Tack, F.; Carleer, R.; Vangronsveld, J.

2012-01-01

This study examines the renewable energy production of crops used for phytoremediation. Our analysis is based on a case study in the Campine region (Belgium and The Netherlands), where agricultural soils are diffusely contaminated with cadmium, lead, and zinc, with an enhanced risk for uptake of these metals in crops and leaching to the groundwater. However, the area has such a large extent (700 km 2 ) that conventional remediation is not applicable. Cultivation of crops for energy purposes on such land offers the opportunity to come up with an approach that efficiently uses contaminated agricultural land and that can be beneficial for both farmer and society. Performing a Life Cycle Analysis (LCA), we examined the energy and CO 2 abatement potential of willow (Salix spp.), silage maize (Zea mays L.), and rapeseed (Brassica napus L.) originating from contaminated land. Taking into account the marginal impact of the metals in the biomass on the energy conversion efficiency and on the potential use of the biomass and its rest products after conversion, digestion of silage maize with combustion of the contaminated digestate shows the best energetic and CO 2 abating perspectives. The replacement of cokes based electricity by willow is more efficient in CO 2 abatement than willow used in a Combined Heat and Power (CHP) unit, despite lower net energy production in the former option. Willow reaches the same energy production and same CO 2 abatement per hectare per year as silage maize when its biomass yield is respectively 13 and 8.7 Mg dm ha −1 y −1 . -- Highlights: ► We study the energy potential of Salix, Zea mays and Brassica after phytoremediation. ► The case study contains agricultural soils that are contaminated with cadmium. ► We include the impact of metals on energy conversion efficiency and rest product use. ► Higher biomass yields for Salix would make it energetically competitive with Z. mays.

Mortality of radio collared willow ptarmigan in Smoela wind-power plant

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Hans Chr.; Broeseth, Henrik; Nilsen, Erlend B.; Sandercock, Brett K.; Bevanger, Kjetil

2011-07-01

Full text: In the project Pre- and post-construction studies of conflicts between birds and wind turbines in coastal Norway (BirdWind), Smoela willow ptarmigan (Lagopus lagopus variegatus) has been one of the species studied. This sub-species represent gallinaceous birds, known to be bad flyers susceptible to collide with artificial structures, e.g. power lines. However, the possible impact of a wind-power plant on survival and behaviour in a willow ptarmigan population was unknown. The objectives of the study were therefore rather wide; to study direct and indirect effects of wind turbines on willow ptarmigan behaviour, habitat selection, reproduction and survival in areas where wind-power plants are established. To collect data on habitat selection, movements, collision risks, avoidance behaviour, survival and general population dynamic parameters, willow ptarmigan were radio-tagged in 2008-2010, using traditional VHF-transmitters (Holohill) with mortality switch, necklace mount, 12 g, lasting for approximately 24 months. Due to low population density and only occasional snow cover, a method using strong lights, dipnet and car was used to catch birds. In total, 34 willow ptarmigan were caught (19 males and 15 females). All birds were caught inside the wind-power plant area (WPA). The birds were radio-tracked at irregular intervals and almost all birds, when found, was located within the WPA. All carcasses of dead birds were examined. When possible, cause of death was determined as; predation (raptor), collision, unknown, other. In total, 28 of the radio-tagged birds have died since January 2008. A Kaplan-Meier analysis of cumulative survival rates, show an exceptionally low survival (<30%). Unlike other willow ptarmigan populations most of the mortality takes place during winter, from December throughout March. Although a thorough analysis of mortality causes has yet not been carried out, a majority of the birds have probably been killed by avian predators and to

Relationships between rare plants of the White Mountains and the late Cenozoic geology of the Colorado Plateau

Science.gov (United States)

Jonathan W. Long

2007-01-01

A complex geologic history has shaped the distribution of Arizona willow (Salix arizonica Dorn) and the Mogollon paintbrush (Castilleja mogollonica Pennell). These subalpine plants do not appear to be strict substrate specialists, but they do seem to favor coarse-textured and well-watered soils. Most of their occupied habitats were...

Cultural Resources Survey of Mile 306.3 to 293.4-R on the Mississippi River, Concordia, Pointe Coupee and West Feliciana Parishes, Louisiana

Science.gov (United States)

1993-01-01

willow (Salix nigra) and pecan (Carya illinoensis ), among others, were abundant and well rooted. The soils in these segments of the project area...or older. Two of the molars have small pit caries . The fourth molar may be from a younger individual, perhaps around 16 years of age. This tooth shows

Biomass power for rural development. Technical progress report Phase-II. Contractual reporting period October-December 1999

Energy Technology Data Exchange (ETDEWEB)

Neuhauser, Edward; The Salix Consortium

2000-03-23

The project undertaken by the Salix Consortium is a multi-phased, multi-partner endeavor. Phase 1 focused on initial development and testing of the technology and forging the necessary agreements to demonstrate commercial willow production. The Phase 1 objectives have been successfully completed: preparing design plans for 2 utility pulverized coal boilers for 20 MW of biopower capacity; developing fuel supply plans for the project with a goal of establishing 365 ha (900 ac) of willow; obtaining power production commitments from the power companies for Phase 2; obtaining construction and environmental permits; and developing an experimental strategy for crop production and power generation improvements needed to assure commercial success. The R and D effort also addresses environmental issues pertaining to introduction of the willow energy system.

Star Formation in Dwarf-Dwarf Mergers: Fueling Hierarchical Assembly

Science.gov (United States)

Stierwalt, Sabrina; Johnson, K. E.; Kallivayalil, N.; Patton, D. R.; Putman, M. E.; Besla, G.; Geha, M. C.

2014-01-01

We present early results from the first systematic study a sample of isolated interacting dwarf pairs and the mechanisms governing their star formation. Low mass dwarf galaxies are ubiquitous in the local universe, yet the efficiency of gas removal and the enhancement of star formation in dwarfs via pre-processing (i.e. dwarf-dwarf interactions occurring before the accretion by a massive host) are currently unconstrained. Studies of Local Group dwarfs credit stochastic internal processes for their complicated star formation histories, but a few intriguing examples suggest interactions among dwarfs may produce enhanced star formation. We combine archival UV imaging from GALEX with deep optical broad- and narrow-band (Halpha) imaging taken with the pre- One Degree Imager (pODI) on the WIYN 3.5-m telescope and with the 2.3-m Bok telescope at Steward Observatory to confirm the presence of stellar bridges and tidal tails and to determine whether dwarf-dwarf interactions alone can trigger significant levels of star formation. We investigate star formation rates and global galaxy colors as a function of dwarf pair separation (i.e. the dwarf merger sequence) and dwarf-dwarf mass ratio. This project is a precursor to an ongoing effort to obtain high spatial resolution HI imaging to assess the importance of sequential triggering caused by dwarf-dwarf interactions and the subsequent affect on the more massive hosts that later accrete the low mass systems.

Choices of action and its influence on farmers' attitudes regarding willow and reed canary grass cultivation; Betydelsen av olika handlingsalternativ foer oekat intresse hos lantbrukare att odla salix och roerflen

Energy Technology Data Exchange (ETDEWEB)

Jonsson, Aasa; Paulrud, Susanne; Laitila, Thomas

2010-02-15

The contribution of energy crops from the agricultural sector is an example of a resource that has a potential to increase substantially in the near future. However, one problem is the lack of interest in cultivating energy crops within the agricultural Several studies have shown that there are a number of reasons for farmers not becoming involved in energy crops. Besides biological aspects, market potential and profitability the farmers are also affected by the available resources on the farm, the effect of the crops on the surroundings, work load, liquidity and the perceived risks. The overall aim with the present study is to increase the knowledge about how to change farmers' attitudes regarding energy crop cultivation, i.e. making them more interested. This study also shows that there is a large fraction of farmers that generally believe they have no or little knowledge of energy crops, such as willow, reed canary grass and hemp. The fraction of farmers considering there is a larger probability of future cultivation of these crops with increased knowledge is also quite large. Energy crop cultivation does not suit everybody. Generally, growing willow and reed canary grass is an alternative for farmers having another business besides agricultural business. Characteristics for these farms are working hours <1500 hours and that the machines are partly owned

Stock characterization and improvement: DNA fingerprinting and cold tolerance of Populus and Salix clones

Energy Technology Data Exchange (ETDEWEB)

Lin, Dolly; Hubbes, M.; Zsuffa, L. [Toronto Univ., ON (Canada). Faculty of Forestry; Tsarouhas, V.; Gullberg, U. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics; Howe, G.; Hackett, W.; Gardner, G.; Furnier, G. [Minnesota Univ., St. Paul, MN (United States). Dept. of Forest Resources; Tuskan, G. [Oak Ridge National Lab., TN (United States)

1998-12-31

Molecular characterization of advanced-generation pedigrees and evaluation of cold tolerance are two aspects of Populus and Salix genetic improvement programmes worldwide that have traditionally received little emphasis. As such, chloroplast DNA markers were tested as a means of determining multi-generation parental contributions to hybrid progeny. Likewise, greenhouse, growth chamber and field studies were used to assess cold tolerance in Populus and Salix. Chloroplast DNA markers did not reveal size polymorphisms among four tested Populus species, but did produce sequence polymorphisms between P. maximowiczii and P. trichocarpa. Additional crosses between multiple genotypes from each species are being used to evaluate the utility of the detected polymorphism for ascertaining parentage within interspecific crosses. Short-day, cold tolerance greenhouse studies revealed that bud set date and frost damage are moderately heritable and genetically correlated in Populus. The relationship between greenhouse and field studies suggests that factors other than short days contribute to cold tolerance in Populus. In Salix, response to artificial fall conditioning varied among full-sibling families, with the fastest growing family displaying the greatest amount of cold tolerance 26 refs, 3 tabs

Growdon Gate/Road Relocation and Property Acquisition Environmental Assessment. Volume 1

Science.gov (United States)

2012-11-01

black walnut (Juglans nigra), pecan ( Carya illinoensis ), blackberry (Rubus sp.), greenbriar (Smilax sp.), poison ivy (Rhus radicans), giant...Riparian Cedar elm (Ulmus crassifolia), black willow (Salix nigra), hackberry (Celtis laevigata), chinaberry (Melia azedarach), pecan ( Carya ... illinoensis ), Canada wildrye (Elymus candensis), poison ivy (Rhus radicans), greenbrier (Smilax spp.), and giant ragweed (Ambrosia trifida) Urban

Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

Science.gov (United States)

Suzuki, Toshitaka N; Kutsukake, Nobuyuki

2017-06-01

Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits ( Poecile montanus ) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

Evaluation of the Efficacy of Crude Extracts of Salix subserrata and ...

African Journals Online (AJOL)

aqueous of Salix subserrata were found to increase the survival time of mice signifi- cantly (P< ... identification and authentication was done using the manual of the Depart- ... Data were analyzed using SPSS version 11.5 for windows software.

Environmental applications of poplars and willows

Science.gov (United States)

J.G. Isebrands; P. Aronsson; M. Carlson; R. Ceulemans; M. Coleman; N. Dickinson; J. Dimitriou; S. Doty; E. Gardiner; K. Heinsoo; J.D. Johnson; Y.B. Koo; J. Kort; J. Kuzovkina; L. Licht; A.R. McCracken; I. McIvor; P. Mertens; K. Perttu; D. Riddell-Black; B. Robins; G. Scarascia-Mugnozza; W.R. Schroeder; John Stanturf; T.A. Volk; M. Weih

2014-01-01

Poplars and willows have been planted for environmental purposes for millennia. There are reports that poplars were planted to improve the human environment 4000 years ago in the third dynasty of Ur, for streamside stabilization 2000 years ago in what is now the south-western USA by native North Americans and for urban amenities by the early Chinese dynasties (see...

The potential of willow and poplar plantations as carbon sinks in Sweden

International Nuclear Information System (INIS)

Rytter, Rose-Marie

2012-01-01

A large share, estimated at 12–25%, of the annual anthropogenic greenhouse gas emissions is attributed to global deforestation. Increasing the forested areas therefore has a positive impact on carbon (C) sequestration and mitigation of high atmospheric CO 2 concentrations. Fast-growing species, such as willow and poplar, are of high interest as producers of biomass for fuel, but also as C sinks. The present study estimated the rate of C sequestration in biomass and soil in willow and poplar plantations. Calculations were based on above- and below-ground biomass production data from field experiments, including fine root turnover, litter decomposition rates, and production levels from commercial plantations. Accumulation of C in woody biomass, above and below ground, was estimated at 76.6–80.1 Mg C ha −1 and accumulation of C in the soil at 9.0–10.3 Mg C ha −1 over the first 20–22 years. The average rates of C sequestration were 3.5–4.0 Mg C ha −1 yr −1 in woody biomass, and 0.4–0.5 Mg C ha −1 yr −1 in the soil. If 400,000 ha of abandoned arable land in Sweden were planted with willow and poplar, about 1.5 Tg C would be sequestered annually in woody biomass and 0.2 Tg C in soils. This would be nearly one tenth of the annual anthropogenic emissions of C in Sweden today. These calculations show the potential of fast-growing plantations on arable land to mitigate the effect of high CO 2 concentrations over a short time span. Knowledge gaps were found during the calculation process and future research areas were suggested. -- Highlights: ► Poplars and willows as producers of biomass for fuel and as C sinks. ► Calculation of C sequestration rates in biomass and soil in willow and poplar plantations. ► Increasing forested areas has positive impact on high CO 2 levels. ► Willow and poplar plantations on arable land mitigate anthropogenic CO 2 emissions.

Combined production of free-range pigs and energy crops – animal behaviour and crop damages

DEFF Research Database (Denmark)

Horsted, Klaus; Kongsted, Anne Grete; Jørgensen, Uffe

2012-01-01

Intensive free-range pig production on open grasslands has disadvantages in that it creates nutrient hotspots and little opportunity for pigs to seek shelter from the sun. Combining a perennial energy crop and pig production might benefit the environment and animal welfare because perennial energy...... crops like willow (Salix sp.) and Miscanthus offer the pigs protection from the sun while reducing nutrient leaching from pig excrements due to their deep rooting system. The objectives of this study were to evaluate how season and stocking density of pigs in a free-range system with zones of willow...

Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau.

Science.gov (United States)

Zhu, Yajuan; Wang, Guojie; Li, Renqiang

2016-01-01

Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land.

Biomass production and control of nutrient leaching of willows using different planting methods with special emphasis on an appraisal of the electrical impedance for roots

Energy Technology Data Exchange (ETDEWEB)

Yang Cao

2011-07-01

Willow reproduction can be achieved through vertically or horizontally planted cuttings. Conventionally, plantations are established by inserting cuttings vertically into the soil. There is, however, a lack of information about the biomass production and nutrient leaching of plantations established through horizontally planted cuttings. A greenhouse experiment and a field trial were carried out to investigate whether horizontally planted Salix schwerinii cuttings have a positive effect on stem yield, root distribution and nutrient leaching in comparison with vertically planted cuttings with different planting densities. The shoots' height of horizontally planted cuttings was significantly smaller than that of vertically planted cuttings during the first two weeks after planting in the pot experiment. Thereafter, no significant effect of planting orientation on the stem biomass was observed in the two conducted experiments. In both experiments the total stem biomass increased with the planting density. It was also found that the fine root biomass and the specific root length were not affected by the planting orientation or density, while the fine root surface area and the absorbing root surface area (ARSA) were affected only by the planting density. The planting orientation did not affect the nutrient concentrations in the soil leachate, apart from SO{sub 4}-S and PO{sub 4}-P in the pot experiment. The ARSA in the pot experiment was assessed by using the earth impedance method. The applicability of this method was evaluated in a hydroponic study of willow cuttings where root and stem were measured independently. Electrical resistance had a good correlation with the contact area of the roots with the solution. However, the resistance depended strongly on the contact area of the stem with the solution, which caused a bias in the evaluation of root surface area. A similar experimental set-up with electrical impedance spectroscopy was employed to study the

The potential of two Salix genotypes for radionuclide/heavy metal accumulation. A case study of Rovinari ash pit (Gorj District, Romania)

Science.gov (United States)

Hernea, Cornelia; Neţoiu, Constantin; Corneanu, Gabriel; Crăciun, Constantin; Corneanu, Mihaela; Cojocaru, Luminiţa; Rovena Lăcătuşu, Anca; Popescu, Ion

2014-05-01

Thermo Electric Power Plants (TEPP) produce a high amount of ash, that contains heavy metals and radionuclides. Ash is usually stored in ash-pits, in mixture with water and contains U235, Th 234 and their decay products, that are released from the coal matrix, during combustion, as well as heavy metals. Warm weather dried the ash and it can be spread by the wind in surrounded area. This paper presents the results of an experiment with two Salix genotypes, cultivated on an old closed ash-pit, nearby the Rovinari TEPP, in the middle Jiu valley (Gorj District, Romania), in order to evaluate its tolerance to heavy metals and radionuclides. Ash analysis revealed the presence of natural radionuclides, beloging from ash and coal dust, as well as of Cs 137, of Chernobil provenance. Radionuclides content over the normal limits for Romania were registered for Th 234, Pb210, U235 and Ra226. The heavy metals level in ash was over the normal limits, but under the alerts limits. In order to establish the woody plants tolerance to heavy metals and radionuclides, it is important to study the seedlings behavior. In this respect Salix alba and Salix viminalis whips and cuttings culture have been establish on Rovinari ash-pit. The observations made on survival and growth rate pointed out the superiority of Salix viminalis behaviour. After a period of three years Salix viminalis registered a 96% survival rate, while in Salix alba annual decreases, reaching to 14%. These results are supported by the radionuclides content in leaves and by the electron microscopy studies. In Salix alba the leaves parenchimatic cells present a low sinthesis activity. The exogenous particles are accumulated in parenchima cells vacuola, the chloroplasts are usually agranal, with few starch grains and mitocondria presents slightly dillated crista. The ultrastructural features of the mature leaf cells, evidenced the natural adaptation of Salix viminalins for development in an environment with a big amount of

Contrasting the community structure of arbuscular mycorrhizal fungi from hydrocarbon-contaminated and uncontaminated soils following willow (Salix spp. L. planting.

Directory of Open Access Journals (Sweden)

Saad El-Din Hassan

Full Text Available Phytoremediation is a potentially inexpensive alternative to chemical treatment of hydrocarbon-contaminated soils, but its success depends heavily on identifying factors that govern the success of root-associated microorganisms involved in hydrocarbon degradation and plant growth stimulation. Arbuscular mycorrhizal fungi (AMF form symbioses with many terrestrial plants, and are known to stimulate plant growth, although both species identity and the environment influence this relationship. Although AMF are suspected to play a role in plant adaptation to hydrocarbon contamination, their distribution in hydrocarbon-contaminated soils is not well known. In this study, we examined how AMF communities were structured within the rhizosphere of 11 introduced willow cultivars as well as unplanted controls across uncontaminated and hydrocarbon-contaminated soils at the site of a former petrochemical plant. We obtained 69 282 AMF-specific 18S rDNA sequences using 454-pyrosequencing, representing 27 OTUs. Contaminant concentration was the major influence on AMF community structure, with different AMF families dominating at each contaminant level. The most abundant operational taxonomic unit in each sample represented a large proportion of the total community, and this proportion was positively associated with increasing contamination, and seemingly, by planting as well. The most contaminated soils were dominated by three phylotypes closely related to Rhizophagus irregularis, while these OTUs represented only a small proportion of sequences in uncontaminated and moderately contaminated soils. These results suggest that in situ inoculation of AMF strains could be an important component of phytoremediation treatments, but that strains should be selected from the narrow group that is both adapted to contaminant toxicity and able to compete with indigenous AMF species.

Contrasting the community structure of arbuscular mycorrhizal fungi from hydrocarbon-contaminated and uncontaminated soils following willow (Salix spp. L.) planting.

Science.gov (United States)

Hassan, Saad El-Din; Bell, Terrence H; Stefani, Franck O P; Denis, David; Hijri, Mohamed; St-Arnaud, Marc

2014-01-01

Phytoremediation is a potentially inexpensive alternative to chemical treatment of hydrocarbon-contaminated soils, but its success depends heavily on identifying factors that govern the success of root-associated microorganisms involved in hydrocarbon degradation and plant growth stimulation. Arbuscular mycorrhizal fungi (AMF) form symbioses with many terrestrial plants, and are known to stimulate plant growth, although both species identity and the environment influence this relationship. Although AMF are suspected to play a role in plant adaptation to hydrocarbon contamination, their distribution in hydrocarbon-contaminated soils is not well known. In this study, we examined how AMF communities were structured within the rhizosphere of 11 introduced willow cultivars as well as unplanted controls across uncontaminated and hydrocarbon-contaminated soils at the site of a former petrochemical plant. We obtained 69 282 AMF-specific 18S rDNA sequences using 454-pyrosequencing, representing 27 OTUs. Contaminant concentration was the major influence on AMF community structure, with different AMF families dominating at each contaminant level. The most abundant operational taxonomic unit in each sample represented a large proportion of the total community, and this proportion was positively associated with increasing contamination, and seemingly, by planting as well. The most contaminated soils were dominated by three phylotypes closely related to Rhizophagus irregularis, while these OTUs represented only a small proportion of sequences in uncontaminated and moderately contaminated soils. These results suggest that in situ inoculation of AMF strains could be an important component of phytoremediation treatments, but that strains should be selected from the narrow group that is both adapted to contaminant toxicity and able to compete with indigenous AMF species.

Infrared Colors of Dwarf-Dwarf Galaxy Interactions

Science.gov (United States)

Liss, Sandra; Stierwalt, Sabrina; Johnson, Kelsey; Patton, Dave; Kallivayalil, Nitya

2015-10-01

We request Spitzer Warm Mission IRAC Channel 1 & 2 imaging for a sample of 60 isolated dwarf galaxy pairs as a key component of a larger, multi-wavelength effort to understand the role low-mass mergers play in galaxy evolution. A systematic study of dwarf-dwarf mergers has never been done, and we wish to characterize the impact such interactions have on fueling star formation in the nearby universe. The Spitzer imaging proposed here will allow us to determine the extent to which the 3.6 and 4.5 mum bands are dominated by stellar light and investigate a) the extent to which interacting pairs show IR excess and b) whether the excess is related to the pair separation. Second, we will use this IR photometry to constrain the processes contributing to the observed color excess and scatter in each system. We will take advantage of the wealth of observations available in the Spitzer Heritage Archive for 'normal' non-interacting dwarfs by comparing the stellar populations of those dwarfs with the likely interacting dwarfs in our sample. Ultimately, we can combine the Spitzer imaging proposed here with our current, ongoing efforts to obtain groundbased optical photometry to model the star formation histories of these dwarfs and to help constrain the timescales and impact dwarf-dwarf mergers have on fueling star formation. The sensitivity and resolution offered by Spitzer are necessary to determine the dust properties of these interacting systems, and how these properties vary as a function of pair separation, mass ratio, and gas fraction.

Biomass power for rural development. Technical progress report, October 1--December 31, 1997

Energy Technology Data Exchange (ETDEWEB)

Neuhauser, E.

1998-05-01

The focus of the DOE/USDA sponsored biomass power for rural development project is to develop commercial energy crops for power generation by the year 2000. The New York based Salix Consortium project is a multi-partner endeavor, implemented in three stages. Phase-1, Final Design and Project Development, will conclude with the preparation of construction and/or operating permits, feedstock production plans, and contracts ready for signature. Field trials of willow (Salix) have been initiated at several locations in New York (Tully, Lockport, King Ferry, La Fayette, Massena, and Himrod) and co-firing tests are underway at Greenidge Station (NYSEG) and Dunkirk Station (NMPC). Phase-2 of the project will focus on scale-up of willow crop acreage, construction of co-firing facilities at Dunkirk Station (NMPC), and final modifications for Greenidge Station. Cofiring willow is also under consideration for GPU`s Seward Station where testing is underway. There will be an evaluation of the energy crop as part of the gasification trials occurring at BED`s McNeill Power Station. Phase-3 will represent fullscale commercialization of the energy crop and power generation on a sustainable basis. During the fourth quarter of 1997 the Consortium submitted a Phase-2 proposal. A few of the other more important milestones are outlined below. The first quarter of 1998 will be dominated by pre-planting activity in the spring.

Satellite dwarf galaxies in a hierarchical universe: the prevalence of dwarf-dwarf major mergers

International Nuclear Information System (INIS)

Deason, Alis; Wetzel, Andrew; Garrison-Kimmel, Shea

2014-01-01

Mergers are a common phenomenon in hierarchical structure formation, especially for massive galaxies and clusters, but their importance for dwarf galaxies in the Local Group remains poorly understood. We investigate the frequency of major mergers between dwarf galaxies in the Local Group using the ELVIS suite of cosmological zoom-in dissipationless simulations of Milky Way- and M31-like host halos. We find that ∼10% of satellite dwarf galaxies with M star > 10 6 M ☉ that are within the host virial radius experienced a major merger of stellar mass ratio closer than 0.1 since z = 1, with a lower fraction for lower mass dwarf galaxies. Recent merger remnants are biased toward larger radial distance and more recent virial infall times, because most recent mergers occurred shortly before crossing within the virial radius of the host halo. Satellite-satellite mergers also occur within the host halo after virial infall, catalyzed by the large fraction of dwarf galaxies that fell in as part of a group. The merger fraction doubles for dwarf galaxies outside of the host virial radius, so the most distant dwarf galaxies in the Local Group are the most likely to have experienced a recent major merger. We discuss the implications of these results on observable dwarf merger remnants, their star formation histories, the gas content of mergers, and massive black holes in dwarf galaxies.

Selecting and utilizing Populus and Salix for landfill covers: implications for leachate irrigation.

Science.gov (United States)

Zalesny, Ronald S; Bauer, Edmund O

2007-01-01

The success of using Populus and Salix for phytoremediation has prompted further use of leachate as a combination of irrigation and fertilization for the trees. A common protocol for such efforts has been to utilize a limited number of readily-available genotypes with decades of deployment in other applications, such as fiber or windbreaks. However, it may be possible to increase phytoremediation success with proper genotypic screening and selection, followed by the field establishment of clones that exhibited favorable potential for cleanup of specific contaminants. There is an overwhelming need for testing and subsequent deployment of diverse Populus and Salix genotypes, given current availability of clonal material and the inherent genetic variation among and within these genera. Therefore, we detail phyto-recurrent selection, a method that consists of revising and combining crop and tree improvement protocols to meet the objective of utilizing superior Populus and Salix clones for remediation applications. Although such information is lacking for environmental clean-up technologies, centuries of plant selection success in agronomy, horticulture, and forestry validate the need for similar approaches in phytoremediation. We bridge the gap between these disciplines by describing project development, clone selection, tree establishment, and evaluation of success metrics in the context of their importance to utilizing trees for phytoremediation.

Available data support protection of the Southwestern Willow Flycatcher under the Endangered Species Act

Science.gov (United States)

Theimer, Tad C.; Smith, Aaron D.; Mahoney, Sean M.; Ironside, Kirsten E.

2016-01-01

Zink (2015) argued there was no evidence for genetic, morphological, or ecological differentiation between the federally endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) and other Willow Flycatcher subspecies. Using the same data, we show there is a step-cline in both the frequency of a mtDNA haplotype and in plumage variation roughly concordant with the currently recognized boundary between E. t. extimus and E. t adastus, the subspecies with which it shares the longest common boundary. The geographical pattern of plumage variation is also concordant with previous song analyses differentiating those 2 subspecies and identified birds in one low-latitude, high-elevation site in Arizona as the northern subspecies. We also demonstrate that the ecological niche modeling approach used by Zink yields the same result whether applied to the 2 flycatcher subspecies or to 2 unrelated species, E. t. extimus and Yellow Warbler (Setophaga petechia). As a result, any interpretation of those results as evidence for lack of ecological niche differentiation among Willow Flycatcher subspecies would also indicate no differentiation among recognized species and would therefore be an inappropriate standard for delineating subspecies. We agree that many analytical techniques now available to examine genetic, morphological, and ecological differentiation would improve our understanding of the distinctness (or lack thereof) of Willow Flycatcher subspecies, but we argue that currently available evidence supports protection of the Southwestern Willow Flycatcher under the Endangered Species Act.

DESIGNING AN OPPORTUNITY FUEL WITH BIOMASS AND TIRE-DERIVED FUEL FOR COFIRING AT WILLOW ISLAND GENERATING STATION

International Nuclear Information System (INIS)

K. Payette; D. Tillman

2001-01-01

During the period October 1, 2000 - December 31, 2000, Allegheny Energy Supply Co., LLC (Allegheny) executed a Cooperative Agreement with the National Energy Technology Laboratory to implement a major cofiring demonstration at the Willow Island Generating Station Boiler No.2. Willow Island Boiler No.2 is a cyclone boiler. Allegheny also will demonstrate separate injection cofiring at the Albright Generating Station Boiler No.3, a tangentially fired boiler. The Allegheny team includes Foster Wheeler as its primary subcontractor. Additional subcontractors are Cofiring Alternatives and N.S. Harding and Associates. This report summarizes the activities associated with the Designer Opportunity Fuel program, and demonstrations at Willow Island and Albright Generating Stations. The second quarter of the project involved completing the designs for each location. Further, geotechnical investigations proceeded at each site. Preparations were made to perform demolition on two small buildings at the Willow Island site. Fuels strategies were initiated for each site. Test planning commenced for each site. A groundbreaking ceremony was held at the Willow Island site on October 18, with Governor C. Underwood being the featured speaker

Declines in populations of Salix caprea L.during forest regeneration after strong herbivore pressure

Directory of Open Access Journals (Sweden)

Janusz B. Faliński

2014-01-01

Full Text Available Communities of broadleaved forest subject to strong pressure from large herbivores underwent degeneration. The relief of this pressure led to regeneration of the community, in which an important role was played by the sallow Salix caprea and other light-seeded pioneer species of tree (Populus tremula, Betula pendula and B. pubescens. Regeneration involving Salix caprea proceeded following the conservatorial protection of the degenerate stands in a reserve and later in Białowieża National Park. The emergence and development of the population of Salix caprea proceeded following the invasion of spruce, which coincided with the period of enhanced animal pressure on broadleaved forest. Salix caprea filled all the gaps in the tree stand arising as a result of the destruction of trees and undergrowth by herbivores (in the years 1892-1915. It also appeared en masse on old, at that time unforested, clearings and felled areas. In these places, Salix caprea created very abundant populations, with particular trees being in good condition, with a habit typical of forest trees and attaining considerable heights. The majority of trees were 50-60 years old at the time of death, although individuals reached 74 years of age. The process of extinction of the sallow population - observed over 19 years on permanent plots and fixed trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of sallow for the forest communities of Białowieża National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the 4-9 last years of life. The extinction of the population is associated with the loss of its primary phenological differentiation and with a change in the sex structure of the population from a prevalence of female trees to a near even distribution of the two sexes. The development of the populations of permanent constituents of the forest

A comparative analysis of genetic differentiation across six shared willow host species in leaf- and bud-galling sawflies.

Directory of Open Access Journals (Sweden)

Sanna A Leppänen

Full Text Available Genetic divergence and speciation in plant-feeding insects could be driven by contrasting selection pressures imposed by different plant species and taxa. While numerous examples of host-associated differentiation (HAD have been found, the overall importance of HAD in insect diversification remains unclear, as few studies have investigated its frequency in relation to all speciation events. One promising way to infer the prevalence and repeatability of HAD is to estimate genetic differentiation in multiple insect taxa that use the same set of hosts. To this end, we measured and compared variation in mitochondrial COI and nuclear ITS2 sequences in population samples of leaf-galling Pontania and bud-galling Euura sawflies (Hymenoptera: Tenthredinidae collected from six Salix species in two replicate locations in northern Fennoscandia. We found evidence of frequent HAD in both species complexes, as individuals from the same willow species tended to cluster together on both mitochondrial and nuclear phylogenetic trees. Although few fixed differences among the putative species were found, hierarchical AMOVAs showed that most of the genetic variation in the samples was explained by host species rather than by sampling location. Nevertheless, the levels of HAD measured across specific pairs of host species were not correlated in the two focal galler groups. Hence, our results support the hypothesis of HAD as a central force in herbivore speciation, but also indicate that evolutionary trajectories are only weakly repeatable even in temporally overlapping radiations of related insect taxa.

Comparing predicted yield and yield stability of willow and Miscanthus across Denmark

DEFF Research Database (Denmark)

Larsen, Søren; Jaiswal, Deepak; Bentsen, Niclas Scott

2016-01-01

was 12.1 Mg DM ha−1 yr−1 for willow and 10.2 Mg DM ha−1 yr−1 for Miscanthus. Coefficent of variation as a measure for yield stability was poorest on the sandy soils of northern and western Jutland and the year-to-year variation in yield was greatest on these soils. Willow was predicted to outyield...... Miscanthus on poor, sandy soils whereas Miscanthus was higher yielding on clay-rich soils. The major driver of yield in both crops was variation in soil moisture, with radiation and precipitation exerting less influence. This is the first time these two major feedstocks for northern Europe have been compared....... The semi-mechanistic crop model BioCro was used to simulate the production of both short rotation coppice (SRC) willow and Miscanthus across Denmark. Predictions were made from high spatial resolution soil data and weather records across this area for 1990-2010. The potential average, rain-fed mean yield...

Greenhouse gas emissions from willow-based electricity: a scenario analysis for Portugal and The Netherlands

NARCIS (Netherlands)

Rebelo de Mira, R.; Kroeze, C.

2006-01-01

This study focuses on greenhouse gas emissions from power plants using willow as fuel compared to those using fossil fuels. More specifically, we quantify emissions of nitrous oxide (N2O) from soils on which willow is grown, and compare these to emissions of carbon dioxide (CO2) from fossil

Impact of abiotic factors on frost resistance and cold acclimation in Salix species and clones

Energy Technology Data Exchange (ETDEWEB)

Fircks, H. von [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Short Rotation Forestry

1996-12-31

The effects of mineral nitrogen, photoperiod and day-night temperature on frost resistance and growth cessation in Salix species and clones are discussed. Increased nitrogen supply and imbalances between nitrogen and other elements might cause extensive frost damage in plants of Salix. Vegetation frosts below -3 deg C reduces the level of annual yield. Although Salix clones differ in resistance to freezing stress, the capacity to recover and grow after frosts are equal essential properties which affect the growth and biomass production of shoots after night frosts in June. Early autumn frosts causing freezing damage not only may delay the onset of growth cessation and cold acclimation, but also affect the winter survival of shoots. Increased nitrogen supply prior to cold acclimation postponed growth cessation and cold acclimation. Differences in nutrient status in plants cause also differences in retranslocation of mineral nutrients. Absence of damaging autumn frosts allow plants irrespective of nitrogen status to develop a frost resistance of at least - 80 deg C. 21 refs, 1 fig, 3 tabs

Satellite dwarf galaxies in a hierarchical universe: the prevalence of dwarf-dwarf major mergers

Energy Technology Data Exchange (ETDEWEB)

Deason, Alis [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA (United States); Wetzel, Andrew [TAPIR, California Institute of Technology, Pasadena, CA (United States); Garrison-Kimmel, Shea, E-mail: alis@ucolick.org [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA (United States)

2014-10-20

Mergers are a common phenomenon in hierarchical structure formation, especially for massive galaxies and clusters, but their importance for dwarf galaxies in the Local Group remains poorly understood. We investigate the frequency of major mergers between dwarf galaxies in the Local Group using the ELVIS suite of cosmological zoom-in dissipationless simulations of Milky Way- and M31-like host halos. We find that ∼10% of satellite dwarf galaxies with M {sub star} > 10{sup 6} M {sub ☉} that are within the host virial radius experienced a major merger of stellar mass ratio closer than 0.1 since z = 1, with a lower fraction for lower mass dwarf galaxies. Recent merger remnants are biased toward larger radial distance and more recent virial infall times, because most recent mergers occurred shortly before crossing within the virial radius of the host halo. Satellite-satellite mergers also occur within the host halo after virial infall, catalyzed by the large fraction of dwarf galaxies that fell in as part of a group. The merger fraction doubles for dwarf galaxies outside of the host virial radius, so the most distant dwarf galaxies in the Local Group are the most likely to have experienced a recent major merger. We discuss the implications of these results on observable dwarf merger remnants, their star formation histories, the gas content of mergers, and massive black holes in dwarf galaxies.

THE FORNAX DWARF GALAXY AS A REMNANT OF RECENT DWARF-DWARF MERGING IN THE LOCAL GROUP

International Nuclear Information System (INIS)

Yozin, C.; Bekki, K.

2012-01-01

We present results from the first numerical analysis to support the hypothesis, first proposed in Coleman et al., that the Fornax dwarf galaxy was formed from the minor merging of two dwarfs about 2 Gyr ago. Using orbits for the Fornax dwarf that are consistent with the latest proper motion measurements, our dynamical evolution models show that the observed asymmetric shell-like substructures can be formed from the remnant of a smaller dwarf during minor merging. These models also predict the formation of diffuse stellar streams. We discuss how these stellar substructures depend on model parameters of dwarf-dwarf merging, and how the intermediate-age subpopulations found in the vicinity of these substructures may be formed from gas accretion in past merger events. We also suggest that one of Fornax's globular clusters originates from a merged dwarf companion, and demonstrate where as yet undetected tidal streams or H I gas formed from the dwarf merging may be found in the outer halo of the Galaxy.

Sex and the single Salix: considerations for riparian restoration

Science.gov (United States)

Thomas D. Landis; David R. Dreesen; R. Kasten Dumroese

2003-01-01

Most restoration projects strive to create a sustain able plant community but exclusive use of vegetatively propagated material may be preventing this goal. The dioecious willows and cottonwoods of the Salicaceae are widely used in riparian restoration projects. Hardwood cuttings have traditionally been used to propagate these species in nurseries, and live stakes,...

Wind in the Willows--Theatre Activity Packet.

Science.gov (United States)

New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

Part of the New York City Board of Education's Early Stages program, and intended for elementary and secondary school teachers who wish to include a unit on theater in their classes, this guide offers suggestions for lessons and activities to accompany viewing a performance of "Wind in the Willows" at the Nederlander Theater. Part one of…

To be or not to be a subspecies: description of Saperda populnea lapponica ssp. n. (Coleoptera, Cerambycidae) developing in downy willow (Salix lapponum L.)

Science.gov (United States)

Wallin, Henrik; Kvamme, Torstein; Bergsten, Johannes

2017-01-01

Abstract A new subspecies of the European cerambycid Saperda populnea (Linnaeus, 1758) is described: Saperda populnea lapponica ssp. n. based on specimens from Scandinavia. The male genitalia characters were examined and found to provide support for this separation, as well as differences in morphology, geographical distribution and bionomy. The preferred host tree for the nominate subspecies S. populnea populnea is Populus tremula L., whereas S. populnea lapponica ssp. n. is considered to be monophagous on Salix lapponum L. DNA sequence data of mitochondrial cytochrome oxidase subunit I (COI) was generated from Scandinavian specimens of S. populnea populnea and specimens representing S. populnea lapponica ssp. n. The two subspecies were not reciprocally monophyletic and genetic distances in COI were small. All synonyms of S. populnea populnea have been considered, and species similar to S. populnea populnea have been examined, and not found to be related to S. populnea lapponica ssp. n. A male lectotype has been designated for each of the two following synonyms: Cerambyx decempunctatus De Geer, 1775, and Saperda salicis Zetterstedt, 1818. The synonymised species from Asia, S. balsamifera (Motshulsky, 1860), is elevated to subspecies: S. populnea balsamifera stat. n. We end with a discussion on the definition of subspecies under the unified species concept. PMID:29187784

GIS-BASED location optimization of a biomass conversion plant on contaminated willow in the Campine region (Belgium)

International Nuclear Information System (INIS)

Voets, Thomas; Neven, An; Thewys, Theo; Kuppens, Tom

2013-01-01

The Campine region is diffusely contaminated with heavy metals like cadmium. Since traditional excavation techniques are too expensive, phytoremediation is preferred as a remediation technique. In a previous study, the biomass potential from phytoremediation of contaminated agricultural land in the Campine region in Belgium was assessed. Based on recently upgraded figures of willow potential from phytoremediation on agricultural land in the seven most contaminated municipalities of the Belgian Campine region, the current paper uses GIS-knowledge to investigate which of three previously identified locations is most suitable for a biomass plant, taking into account the spatial distribution of the contaminated willow supply and the total cost of willow transport. Biomass transport distance from the centroid of each contaminated agricultural parcel to each of the three potential biomass plant locations was determined following Euclidian distance calculations and distance calculations over the existing road network. A transport cost model consisting of distance fixed and distance dependent biomass transport costs was developed. Of the locations identified, the Overpelt Fabriek site results in the lowest biomass transport distance and costs. When willow allocation for each parcel occurs based on the nearest potential plant location, transport costs are on average 23% lower than when all biomass is transported to the single Overpelt Fabriek site location. Therefore, when only considering transport costs, installing a smaller plant at each of the three potential plant locations would be less expensive than when installing a single biomass plant at the Overpelt Fabriek site. -- Highlights: ► Overpelt Fabriek site most attractive for time frames considered. ► Average tortuosity factor in Campine region between 1.27 and 1.42. ► Share of willow transport costs in willow supply costs 21%. ► Optimal allocation of willow results in lower transport costs

Estonian energy forest project

International Nuclear Information System (INIS)

Koppel, A.; Kirt, E.; Kull, K.; Lasn, R.; Noormets, A.; Roostalu, H.; Ross, J.; Ross, V.; Sulev, M.

1994-04-01

In February 1993 an agreement of Swedish-Estonian scientific co-operation on energy forest was signed. In may five energy forest plantations (altogether 2 ha) were established in Estonia with Swedish selected clones of Salix viminalis and Salix dasyclados. The research within this project is carried out within three main directions. The studies of basic ecophysiological processes and radiation regime of willow canopy will be carried out in Toravere. The production ecology studies, comparison of the productivity of multiple clones on different soil types is based on the plantations as vegetation filter for wastewater purification is studied on the basis of plantations in Vaeike-Maarja and Valga (author)

Yield and Water Quality Impacts of Field-Scale Integration of Willow into a Continuous Corn Rotation System.

Science.gov (United States)

Zumpf, Colleen; Ssegane, Herbert; Negri, Maria Cristina; Campbell, Patty; Cacho, Julian

2017-07-01

Agricultural landscape design has gained recognition by the international environmental and development community as a strategy to address multiple goals in land, water, and ecosystem service management; however, field research is needed to quantify impacts on specific local environments. The production of bioenergy crops in specific landscape positions within a grain-crop field can serve the dual purpose of producing cellulosic biomass (nutrient recovery) while also providing regulating ecosystem services to improve water quality (nutrient reduction). The effectiveness of such a landscape design was evaluated by the strategic placement of a 0.8-ha short-rotation shrub willow ( Seemen) bioenergy buffer along marginal soils in a 6.5-ha corn ( L.) field in a 6-yr field study in central Illinois. The impact of willow integration on water quality (soil water, shallow groundwater leaching, and crop nutrient uptake) and quantity (soil moisture and transpiration) was monitored in comparison with corn in the willow's first cycle of growth. Willows significantly reduced nitrate leachate in shallow subsurface water by 88% while maintaining adequate nutrient and water usage. Results suggest that willows offer an efficient nutrient-reduction strategy and may provide additional ecosystem services and benefits, including enhanced soil health. However, low values for calculated willow biomass will need to be readdressed in the future as harvest data become available to understand contributing factors that affected productivity beyond nutrient availability. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Arthropods of native and exotic vegetation and their association with willow flycatchers and Wilson's warblers

Science.gov (United States)

Linda S. DeLay; Deborah M. Finch; Sandra Brantley; Richard Fagerlund; Michael D. Means; Jeffrey F. Kelly

1999-01-01

We compared abundance of migrating Willow Flycatchers and Wilson's Warblers to the abundance of arthropods in exotic and native vegetation at Bosque del Apache National Wildlife Refuge. We trapped arthropods using glue-boards in 1996 and 1997 in the same cottonwood, saltcedar, and willow habitats where we mist-netted birds during spring and fall migration. There...

Environmental performance of gasified willow from different lands including land-use changes

DEFF Research Database (Denmark)

Saez de Bikuna Salinas, Koldo; Hauschild, Michael Zwicky; Pilegaard, Kim

2017-01-01

A life-cycle assessment (LCA) of a low-input, short rotation coppice (SRC) willow grown on different Danish lands was performed. Woodchips are gasified, producer gas is used for co-generation of heat and power (CHP) and the ash-char output is applied as soil amendment in the field. A hybrid model...... for abandoned farmland, as a relative C stock loss compared to natural regeneration. ILUC results show that area related GHG emissions are dominant (93% of iLUCfood and 80% of iLUCfeed), transformation being more important (82% of iLUCfood) than occupation (11%) impacts. LCA results show that CHP from willow...

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0)

Science.gov (United States)

2010-05-01

monophylla or P. edulis), junipers (Juniperus), cottonwoods (e.g., Populus fremontii), willows (Salix), or hardwoods (e.g., Quercus , Platanus...pine in association with incense cedar and California black oak ( Quercus kelloggii) on the western slopes and Jeffrey pine on the eastern slopes...corkbark fir (Abies lasiocarpa var. arizonica ), limber pine (Pinus flexilis), and bristlecone pine (P. aristata) (Bailey 1995). Black Hills (MLRA

Naming Disney's Dwarfs.

Science.gov (United States)

Sidwell, Robert T.

1980-01-01

Discusses Disney's version of the folkloric dwarfs in his production of "Snow White" and weighs the Disney rendition of the dwarf figure against the corpus of traits and behaviors pertaining to dwarfs in traditional folklore. Concludes that Disney's dwarfs are "anthropologically true." (HOD)

Ecophysiology of riparian cottonwood and willow before, during, and after two years of soil water removal.

Science.gov (United States)

Hultine, K R; Bush, S E; Ehleringer, J R

2010-03-01

Riparian cottonwood/willow forest assemblages are highly valued in the southwestern United States for their wildlife habitat, biodiversity, and watershed protection. Yet these forests are under considerable threat from climate change impacts on water resources and land-use activities to support human enterprise. Stream diversions, groundwater pumping, and extended drought have resulted in the decline of cottonwood/willow forests along many riparian corridors in the Southwest and, in many cases, the replacement of these forests with less desirable invasive shrubs and trees. Nevertheless, ecophysiological responses of cottonwood and willow, along with associated ecohydrological feedbacks of soil water depletion, are not well understood. Ecophysiological processes of mature Fremont cottonwood and coyote willow stands were examined over four consecutive growing seasons (2004-2007) near Salt Lake City, Utah, USA. The tree stands occurred near the inlet of a reservoir that was drained in the spring of 2005 and remained empty until mid-summer of 2006, effectively removing the primary water source for most of two growing seasons. Stem sap flux density (Js) in cottonwood was highly correlated with volumetric soil moisture (theta) in the upper 60 cm and decreased sevenfold as soil moisture dropped from 12% to 7% after the reservoir was drained. Conversely, Js in willow was marginally correlated with 0 and decreased by only 25% during the same period. Opposite patterns emerged during the following growing season: willow had a lower whole-plant conductance (kt) in June and higher leaf carbon isotope ratios (delta13C) than cottonwood in August, whereas k(t) and delta13C were otherwise similar between species. Water relations in both species recovered quickly from soil water depletion, with the exception that sapwood area to stem area (As:Ast) was significantly lower in both species after the 2007 growing season compared to 2004. Results suggest that cottonwood has a greater

Temperatures and luminosities of white dwarfs in dwarf novae

International Nuclear Information System (INIS)

Smak, J.

1984-01-01

Far ultraviolet radiation observed in dwarf novae at minimum can only be attributed to their white dwarfs. In three systems white dwarfs are detected directly through their eclipses. These data are used to determine the effective temperatures and luminosities of white dwarfs. The resulting temperatures range from about logT e = 4.1 to about 4.9, with typical values of about 4.5. The luminosities range from about logL 1 = 31.0 to about 33.5 and show correlation with the average accretion rates. Radiation from white dwarfs is likely to be the source of excitation of the emission lines from disks. It is also argued that the heating by the white dwarf can significantly modify the structure of the innermost parts of the disk and, particularly, inhibit the incidence of thermal instability in that region. 26 refs., 2 figs., 1 tab. (author)

Some environmental impacts of short rotation willow coppice

International Nuclear Information System (INIS)

Slater, F.M.; Hodson, R.W.; Randrson, P.F.; Lynn, S.F.

1997-01-01

Short rotation willow coppice is a relatively new crop in upland Britain, and particularly in Environmentally Sensitive Areas the conservation and environmental effect of biomass crops needs to be evaluated. Investigations of sewage-sludge-treated plots in mid-Wales show that, because weed control was inadequate, recovery of the flora to its semi-natural precultivated state was rapid within and between experimental plots. Soil invertebrates responded to temporal stimuli before all else. Foliar-feeding invertebrates were greater in plots which had added fertilizer. Following cultivation voles were generally lost from the ploughed areas but field mice remained. Birds were studied in more extensive areas of short rotation coppice in central England and the assemblage of species was found to be similar to those found in conventional coppice but with a foreshortened successional sequence. The conservation value of short rotation willow coppice lies mainly in the abundant foliar invertebrates that provide a rich source of food for small passerine birds, particularly summer migrants. It also provides good cover for game birds - and their predators. (author)

Characterization and reactions of a Salix extractive with a unique ring system

Science.gov (United States)

Lawrence Landucci; Sally Ralph; Kolby Hirth

2003-01-01

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations.

Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees.

Science.gov (United States)

Algreen, Mette; Trapp, Stefan; Rein, Arno

2014-01-01

The main purpose of this study was to determine typical concentrations of heavy metals (HM) in wood from willows and poplars, in order to test the feasibility of phytoscreening and phytoextraction of HM. Samples were taken from one strongly, one moderately, and one slightly polluted site and from three reference sites. Wood from both tree species had similar background concentrations at 0.5 mg kg(-1) for cadmium (Cd), 1.6 mg kg(-1) for copper (Cu), 0.3 mg kg(-1) for nickel (Ni), and 25 mg kg(-1) for zinc (Zn). Concentrations of chromium (Cr) and lead (Pb) were below or close to detection limit. Concentrations in wood from the highly polluted site were significantly elevated, compared to references, in particular for willow. The conclusion from these results is that tree coring could be used successfully to identify strongly heavy metal-polluted soil for Cd, Cu, Ni, Zn, and that willow trees were superior to poplars, except when screening for Ni. Phytoextraction of HMs was quantified from measured concentration in wood at the most polluted site. Extraction efficiencies were best for willows and Cd, but below 0.5% over 10 years, and below 1‰ in 10 years for all other HMs.

Radiocaesium uptake and cycling in willow short rotation coppice

International Nuclear Information System (INIS)

Gommers, A.

2002-01-01

The document is an abstract of a PhD thesis. The study investigates the uptake and cycling of radiocaesium in willow short rotation coppice. Different factors influencing the soil-to-wood transfer of radiocaesium were investigated, among others the type of minerals, supply of potassium and soil composition

Habitat and sex differences in physiological condition of breeding Southwestern Willow Flycatchers (Empidonax traillii extimus)

Science.gov (United States)

Owen, J.C.; Sogge, M.K.; Kern, M.D.

2005-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus; here- after “flycatcher”) is a federally listed endangered species that breeds in densely vegetated riparian habitats dominated by native and exotic plants, including introduced monotypic saltcedar (Tamarix ramosissima). Some workers have theorized that saltcedar is unsuitable habitat for the flycatcher, primarily because it generally supports a smaller and less diverse invertebrate community (the flycatcher's food base) than native habitats (e.g. Salix spp.). However, differences in insect communities between native and saltcedar habitats are not proof that saltcedar habitats are inferior. The only way to evaluate whether the habitats differ in dietary or energetic quality is to document actual food limitation or its manifestations. Measurements of an individual's body condition and metabolic state can serve as indicators of environmental stressors, such as food limitation and environmental extremes. We captured 130 flycatchers breeding in native and saltcedar habitats in Arizona and New Mexico and measured 12 variables of physiological condition. These variables included body mass, fat level, body condition index, hematocrit, plasma triglycerides, plasma free fatty acids and glycerol, plasma glucose and beta-hydroxybutyrate, plasma uric acid, total leukocyte count, and heterophil-to-lymphocyte ratio. We found substantial sex-based differences in the condition of male and female flycatchers. Ten of the 12 measures of physiological condition differed significantly between the sexes. In all cases where male and female condition differed (except mass), the differences suggest that males were in poorer condition than females. We found few habitat-based differences in flycatcher condition. Only 3 of the 12 physiological condition indices differed significantly between habitats. Our data show that, at least in some parts of the flycatcher's range, there is no evidence that flycatchers breeding in

Spatial distribution of arsenic and heavy metals in willow roots from a contaminated floodplain soil measured by X-ray fluorescence spectroscopy

International Nuclear Information System (INIS)

Zimmer, Dana; Kruse, Jens; Baum, Christel; Borca, Camelia; Laue, Michael; Hause, Gerd; Meissner, Ralph; Leinweber, Peter

2011-01-01

Under changing redox conditions some plants create plaques at their root surface, which may affect the mobility and uptake of As and heavy metals but it is unknown to what extent this also holds true for willows in contaminated floodplain soils. Therefore, willow roots were sampled from a phytoremediation trial in the contaminated floodplain of the river Elbe (Germany), cryofixed, freeze-dried, and cross sections were mapped for the distribution of As, Ca, Cu, Fe, K, Mn, Ni, S and Zn by synchrotron based X-ray fluorescence spectroscopy. The elements Ca, Cu, Ni, S and Zn were concentrated in the aerenchymatic tissue, and not associated with Fe and Mn. Mixed Fe-Mn plaques covered the surface of the willow roots and As was accumulated in these plaques. The observed association pattern between As and Fe was explained by the different sorption/desorption properties of As(III) and As(V). The Cu and Zn intensities were not associated with the intensity of Fe in the plaque, which seems to be a willow-specific difference compared to other wetland plants. These results suggested that willows are especially suited to stabilize low-phytoextractable elements like Cu and As in their roots and rhizosphere. Thus, short rotation coppicing of willows may be a practical approach to mitigate the adverse effects of floodplain soil contamination. - Research highlights: → Elemental distributions were mapped on willow roots for the first time by synchrotron-based X-ray fluorescence. → Ca, Cu, Ni, S and Zn were enriched in the aerenchyma but As, Fe and Mn formed root plaques. → The Cu and Zn enrichments in aerenchyma but absence in plaques appeared to be willow-specific. → In the plaques were three groups of pixels which strongly differed in the As to Fe and As to Mn ratios. → This indicated different species of these redox-sensitive elements.

Spatial distribution of arsenic and heavy metals in willow roots from a contaminated floodplain soil measured by X-ray fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Zimmer, Dana, E-mail: dana.zimmer@uni-rostock.de [Soil Science, University of Rostock, Justus-von-Liebig-Weg 6, D-18051 Rostock (Germany); Kruse, Jens; Baum, Christel [Soil Science, University of Rostock, Justus-von-Liebig-Weg 6, D-18051 Rostock (Germany); Borca, Camelia [Paul Scherrer Institute, Swiss Light Source, CH-5232 Villigen PSI (Switzerland); Laue, Michael [Electron Microscopy Centre, University of Rostock, Medical Faculty, Strempelstr. 14, D-18057 Rostock (Germany); Hause, Gerd [Microscopy Unit, Biocenter of the University of Halle, Weinbergweg 22, D-06120 Halle/Saale (Germany); Meissner, Ralph [UFZ-Helmholtz Centre for Environmental Research, Department of Soil Physics, Lysimeter Station, Dorfstrasse 55, D-39615 Falkenberg (Germany); Leinweber, Peter [Soil Science, University of Rostock, Justus-von-Liebig-Weg 6, D-18051 Rostock (Germany)

2011-09-01

Under changing redox conditions some plants create plaques at their root surface, which may affect the mobility and uptake of As and heavy metals but it is unknown to what extent this also holds true for willows in contaminated floodplain soils. Therefore, willow roots were sampled from a phytoremediation trial in the contaminated floodplain of the river Elbe (Germany), cryofixed, freeze-dried, and cross sections were mapped for the distribution of As, Ca, Cu, Fe, K, Mn, Ni, S and Zn by synchrotron based X-ray fluorescence spectroscopy. The elements Ca, Cu, Ni, S and Zn were concentrated in the aerenchymatic tissue, and not associated with Fe and Mn. Mixed Fe-Mn plaques covered the surface of the willow roots and As was accumulated in these plaques. The observed association pattern between As and Fe was explained by the different sorption/desorption properties of As(III) and As(V). The Cu and Zn intensities were not associated with the intensity of Fe in the plaque, which seems to be a willow-specific difference compared to other wetland plants. These results suggested that willows are especially suited to stabilize low-phytoextractable elements like Cu and As in their roots and rhizosphere. Thus, short rotation coppicing of willows may be a practical approach to mitigate the adverse effects of floodplain soil contamination. - Research highlights: {yields} Elemental distributions were mapped on willow roots for the first time by synchrotron-based X-ray fluorescence. {yields} Ca, Cu, Ni, S and Zn were enriched in the aerenchyma but As, Fe and Mn formed root plaques. {yields} The Cu and Zn enrichments in aerenchyma but absence in plaques appeared to be willow-specific. {yields} In the plaques were three groups of pixels which strongly differed in the As to Fe and As to Mn ratios. {yields} This indicated different species of these redox-sensitive elements.

Differential impacts of willow and mineral fertilizer on bacterial communities and biodegradation in diesel fuel oil-contaminated soil

Directory of Open Access Journals (Sweden)

Mary-Cathrine C.E. Leewis

2016-06-01

Full Text Available Despite decades of research there is limited understanding of how vegetation impacts the ability of microbial communities to process organic contaminants in soil. Using a combination of traditional and molecular assays, we examined how phytoremediation with willow and/or fertilization affected the microbial community present and active in the transformation of diesel contaminants. In a pot study, willow had a significant role in structuring the total bacterial community and resulted in significant decreases in diesel range organics (DRO. However, stable isotope probing (SIP indicated that fertilizer drove the differences seen in community structure and function. Finally, analysis of the total variance in both pot and SIP experiments indicated an interactive effect between willow and fertilizer on the bacterial communities. This study clearly demonstrates that a willow native to Alaska accelerates DRO degradation, and together with fertilizer, increased aromatic degradation by shifting microbial community structure and the identity of active naphthalene degraders.

Buffalo Harbor Study. Preliminary Feasibility Report. Volume I. Main Report.

Science.gov (United States)

1983-04-01

to usually narrow strips of riparian vegetation, which is composed of various trees and shrubs of the Salix genus (willow), sumac, aspen, boxelder...reptiles were found. Species included, leopard frogs, snapping turtles, painted turtle, and garter snakes (SUNY Brockport: 1982). (7) Endangered Species...vessel traffic on the Buffalo River causes interrupted truck service. Firms have also cited snow removal as a problem. The harbor area road service

Central Radar System, Over-the-Horizon Backscatter

Science.gov (United States)

1990-03-09

Magnolia virginiana Switchgrass Panicum virgatum FAC+ Tall mannagrass Glyceria grandis OBL Water fern Salvinia spp. and Marsilea vestita OBL Water...boxelder, (Acer negundo), oaks (Quercus spp.), willows (Salix spp.), chokecherry (Prunus virginiana ), plum (Prunus spp.), and russian olive (Elaeagnus...maintenance of the power lines may be required to trim or prune trees which may interfere with the lines. With the exception of the pole sites, the only

Sterling C. Robertson Dam and Limestone Lake on the Navasota River, Texas (Leon, Limestone and Robertson Counties).

Science.gov (United States)

1976-04-01

flatsedge (Cyperus s p.) , and Spanish mulberry (Callicarpa americana). Common bottomland forest species included pecan ( Carya illinoensis ), post...ona-wiibT Bull Briar Smilax glauca Cat Greenbriar Salix nigra Black Willow Carya illinoensis Pecan Carya texana Black Hickory Q-erustlefata Post Oak... illinoensis ), post oak (Quercus stellata). hackberry (Ce/is sp.), elm (Ulmus sp.), and holly. Species common in the prairie site included Croton sp., prairie

Vegetation Resources of Rocky Mountain Arsenal, Adams County, Colorado

Science.gov (United States)

1989-10-01

SUCCULENTS Opuntia polyacantha Plains Prickly Pear Cactaceae Table 4 .(cont’d.) Scientific Name Common Name Family Name Yucca glauca Spanish Bayonet Agavaceae...Lycium halimitolium Matrim~ony Bush Solanceae Salix exigua Coyote Willow Salicaceae CACTI AND SUCCULENTS Coryphantha vivipara Ball Cactus Cactaceae ...Qpuntia compressa Prickly Pear Cactus Cactaceae Opuntia polyacantha Plains Prickly Pear Cactaceae Yucca glauca Spanish Bayonet Agavaceae cq Nl Nl Co~ V c0

Distribution, activity and range use of male caribou in early summer in Northern Yukon, Canada

Directory of Open Access Journals (Sweden)

Arthur M. Martell

1986-06-01

Full Text Available Males of the Porcupine Caribou Herd separated from females from the onset of spring migration until they joined them on the calving grounds in late June or early July, 4-6 weeks later. From late May to late June males spent an average of 50% of their time feeding and less than 2% standing and trotting/running. Males spent an average of 29% of their time lying and 19% walking, except in mid-June (40% lying, 6% walking. The average lengths of active and resting periods were 112 minutes and 104 minutes, respectively, from late May to mid-June, but decreased sharply in late June to 78 minutes and 69 minutes, respectively. Tussock meadows were selected in late May and early June, wet sedge meadows were avoided until late June, dwarf shrub heaths were avoided after late May, and alluvial willow thickets were avoided in late May and early June but were selected in mid-June and late June. Caribou fed primarily on lichens and Vaccinium in late May, lichens and Eriophorum in early June, Eriophorum in mid-June and Salix in late June.

Woody plant willow in function of river water protection

Directory of Open Access Journals (Sweden)

Babincev Ljiljana M.

2011-01-01

Full Text Available Coastal area surrounding the river Ibar, in the area between cities of Kosovska Mitrovica and Leposavić in the north of Kosovo and Metohija, is occupied with seven industrial waste dumps. These dumps were all part of the exploitation and flotation refinement of raw mineral materials, metallurgic refinement of concentrates, chemical industry, industrial refinement and energetic facilities of Trepča industrial complex. The existing waste dumps, both active and inactive, are of heterogenic chemical composition. Its impact on the river water is shown by the content of heavy metals found in it. Removal of lead, cadmium and zinc would be economically unrewarding, regardless of the technology used. Wooden plant that prevails in this area is white willow. This work is focused on the removal of heavy metals (Pb, Cd and Zn from the water of the river Ibar using white willow. Roots of the willow are cultivated using the method of water cultures in an individual solution of heavy metals and river water sample. The preparation of the samples for analysis was performed by burning the herbal material and dissolving ashes in the appropriate acids. The concentrations of metals were determined by the stripping analysis. In the investigated heavy metal solutions the biomass increase is 25.6% in lead solution, 27.3% in cadmium and 30.7% in zinc solution. The increase of biomass in nutritional solution, without the heavy metals, is 32.4% and in river water sample 27.5%. The coefficient of bioaccumulation in solutions with heavy metals is 1.6% in lead solution, 1.9% in cadmium and 2.2% in zinc solution. Heavy metals accumulation is 18.74 μg of lead, 20.09 μg of cadmium and 22.89 μg of zinc. The coefficient of bioaccumulation of the water samples, that contained 44.83 μg/dm3 of lead, 29.21 μg/dm3 of cadmium and 434.00 μg/dm3 of zinc, during the period of 45 days, was 30.3% for lead, 53.4% for cadmium and 3.9% for zinc. The concentrations of accumulated metals

An unsuccessful search for brown dwarf companions to white dwarf stars

Science.gov (United States)

Shipman, Harry L.

1986-01-01

The results of a survey to detect excess infrared emission from white dwarf stars which would be attributable to a low mass companion are reviewed. Neither a simple comparison of spectroscopically identified white dwarf stars with the IRAS Point Source Catalog nor the coadding of IRAS survey data resulted in a detection of a brown dwarf. The seven nearest stars where the most stringent limits to the presence of a brown dwarf were obtained are listed, and an effort to detect brown dwarfs in the solar neighborhood is discussed.

The Development of improved willow clones for eastern North America

Science.gov (United States)

R. F. Kopp; L. B. Smart; C. A. Maynard; J. G. Isebrands; G. A. Tuskan; L. P. Abrahamson

2001-01-01

Efforts aimed at genetic improvement of Salix are increasing in North America.Most of these are directed towards developing improved clones for biomass production, phytoremediation, nutrient filters, and stream bank stabilization in the Northeast and North-central United States. Native species are of primary interest, but a small number of clones containing non-native...

Accumulation of Elements in Salix and Other Species Used in Vegetation Filters with Focus on Wood Fuel Quality

Energy Technology Data Exchange (ETDEWEB)

Adler, Anneli

2007-07-01

Woody or herbaceous perennials used as vegetation filters for treatment of different types of wastes can be suitable for production of solid biofuels when their above ground harvestable biomass yield is sufficiently high and when biomass contains appropriate concentrations of minerals with regard to fuel combustion processes. The concentrations of nitrogen (N), potassium (K) and heavy metals (especially Zn and Cd) in fuel should be low and calcium (Ca) concentrations high to avoid technical problems and environmentally harmful emissions during combustion. Since soil supplementation with essential elements improves biomass yield, a conflict might arise between yield and quality aims. There are various possibilities to influence fuel quality during the growing phase of the life cycle of perennial biomass crops. This study assessed the suitability of two deciduous woody perennials (Salix and Populus) and two summer green herbaceous perennials (Phragmites and Urtica) for phytoremediation in terms of growth and nutrient allocation patterns. Salix and Populus proved suitable as vegetation filters when nutrients were available to plants in near-optimal proportions, but when unbalanced nutrient solutions (wastewater) were applied, stem biomass fraction was strongly reduced. Phragmites was more tolerant to wastewater treatment in terms of plant biomass production and nutrient allocation patterns, so if the N:P ratio of the wastewater is suboptimal, a vegetation filter using Phragmites could be considered. In further studies, a method was developed to determine the proportions of nutrient-rich bark in coppiced Salix, while heavy metal phytoextraction capacity was assessed in two Salix vegetation filters. The relevance of proportion of bark on wood fuel quality and element removal from vegetation filters was also investigated. The concentrations of the elements studied in harvestable Salix shoot biomass were higher, meaning lower wood fuel quality, in plantations where

White dwarf radii and boundary-layer constraints in three dwarf novae

International Nuclear Information System (INIS)

Wood, J.H.

1990-01-01

The structure of the boundary layer between the accretion disc and white dwarf in three quiescent dwarf novae is explored with high signal-to-noise eclipse light curves obtained by phase folding 12-20 eclipses. Models of the eclipse shapes of various white dwarf/boundary layer configurations that might be at the centres of the accretion discs are calculated and compared with observations of the eclipses in Z Cha, OY Car and HT Cas. Possible models for the central objects are found to be a white dwarf with or without its lower hemisphere occulted by the disc, or a white dwarf with an optically thick boundary layer significantly extended in latitude up and down its sides. The most likely of these models for each system is an unocculted white dwarf with no boundary layer contributing significantly to the optical flux, or a white dwarf totally covered by an optically thick boundary layer. (author)

Above- and Belowground Development of a Fast-Growing Willow Planted in Acid-Generating Mine Technosol.

Science.gov (United States)

Guittonny-Larchevêque, M; Lortie, S

2017-11-01

Surface metal mining produces large volumes of waste rocks. If they contain sulfide minerals, these rocks can generate a flow of acidic water from the mining site, known as acid mine drainage (AMD), which increases trace metals availability for plant roots. Adequate root development is crucial to decreasing planting stress and improving phytoremediation with woody species. However, techniques to improve revegetation success rarely take into account root development. An experiment was conducted at a gold mine in Quebec, Canada, to evaluate the establishment ability over 3 yr of a fast-growing willow ( Sx64) planted in acid-generating waste rocks. The main objective was to study root development in the soil profile and trace element accumulation in leaves among substrates varying in thickness (0, 20, and 40 cm of soil) and composition (organic carbon [OC] and alkaline AMD treatment sludge). Trees directly planted in waste rocks survived well (69%) but had the lowest productivity (lowest growth in height and diameter, aerial biomass, total leaf area, and root-system size). By contrast, the treatment richer in OC showed the greatest aerial biomass and total leaf area the first year; the thicker treatment resulted in the greatest growth in height and diameter, aboveground biomass, and root-system size in both the first and third years. Willow root development was restricted to soil layers during the first year, but this restriction was overcome in the third year after planting. Willow accumulation factors in leaves were below one for all investigated trace metals except for zinc (Zn), cadmium (Cd), and strontium. For Cd and Zn, concentrations increased with time in willow foliage, decreasing the potential of this willow species use for phytostabilization, despite its ability to rapidly develop extensive root systems in the mine Technosol. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

SATELLITE DWARF GALAXIES IN A HIERARCHICAL UNIVERSE: THE PREVALENCE OF DWARF-DWARF MAJOR MERGERS

OpenAIRE

Deason, A; Wetzel, A; Garrison-Kimmel, S

2014-01-01

Mergers are a common phenomenon in hierarchical structure formation, especially for massive galaxies and clusters, but their importance for dwarf galaxies in the Local Group remains poorly understood. We investigate the frequency of major mergers between dwarf galaxies in the Local Group using the ELVIS suite of cosmological zoom-in dissipationless simulations of Milky Way- and M31-like host halos. We find that ~10% of satellite dwarf galaxies with M_star > 10^6 M_sun that are within the host...

White dwarf heating and the ultraviolet flux in dwarf novae

International Nuclear Information System (INIS)

Pringle, J.E.

1988-01-01

An investigation is made of the heating of the outer layers of the white dwarf which is likely to occur during a dwarf nova outburst. It is shown that the decline in IUE flux, observed during quiescent intervals in the dwarf novae VW Hydri and WX Hydri, may be due to the outer layers cooling off once the heat source is removed. The calculations here assume uniformity of the heat source over the white dwarf surface. This is unlikely to be realized from disc accretion, and we discuss that further calculations are required. (author)

Searching for benchmark systems containing ultra-cool dwarfs and white dwarfs

Directory of Open Access Journals (Sweden)

Pinfield D.J.

2013-04-01

Full Text Available We have used the 2MASS all-sky survey and WISE to look for ultracool dwarfs that are part of multiple systems containing main sequence stars. We cross-matched L dwarf candidates from the surveys with Hipparcos and Gliese stars, finding two new systems. We consider the binary fraction for L dwarfs and main sequence stars, and further assess possible unresolved multiplicity within the full companion sample. This analysis shows that some of the L dwarfs in this sample might actually be unresolved binaries themselves. We have also identified a sample of common proper motion systems in which a main sequence star has a white dwarf as wide companion. These systems can help explore key issues in star evolution theory, as the initial-final mass relationship of white dwarfs, or the chromospheric activity-age relationship for stars still in the main sequence. Spectroscopy for 50 white dwarf candidates, selected from the SuperCOSMOS Science Archive, was obtained. We have also observed 6 of the main sequence star companions, and have estimated their effective temperatures, rotational and microturbulent velocities and metallicities.

Spatial distribution of arsenic and heavy metals in willow roots from a contaminated floodplain soil measured by X-ray fluorescence spectroscopy.

Science.gov (United States)

Zimmer, Dana; Kruse, Jens; Baum, Christel; Borca, Camelia; Laue, Michael; Hause, Gerd; Meissner, Ralph; Leinweber, Peter

2011-09-01

Under changing redox conditions some plants create plaques at their root surface, which may affect the mobility and uptake of As and heavy metals but it is unknown to what extent this also holds true for willows in contaminated floodplain soils. Therefore, willow roots were sampled from a phytoremediation trial in the contaminated floodplain of the river Elbe (Germany), cryofixed, freeze-dried, and cross sections were mapped for the distribution of As, Ca, Cu, Fe, K, Mn, Ni, S and Zn by synchrotron based X-ray fluorescence spectroscopy. The elements Ca, Cu, Ni, S and Zn were concentrated in the aerenchymatic tissue, and not associated with Fe and Mn. Mixed Fe-Mn plaques covered the surface of the willow roots and As was accumulated in these plaques. The observed association pattern between As and Fe was explained by the different sorption/desorption properties of As(III) and As(V). The Cu and Zn intensities were not associated with the intensity of Fe in the plaque, which seems to be a willow-specific difference compared to other wetland plants. These results suggested that willows are especially suited to stabilize low-phytoextractable elements like Cu and As in their roots and rhizosphere. Thus, short rotation coppicing of willows may be a practical approach to mitigate the adverse effects of floodplain soil contamination. Copyright © 2011 Elsevier B.V. All rights reserved.

Cadmium concentrations in tissues of willow ptarmigan (Lagopus lagopus) and rock ptarmigan (Lagopus muta) in Nunavik, Northern Quebec

Energy Technology Data Exchange (ETDEWEB)

Rodrigue, Jean [Environment Canada, Service canadien de la faune, 1141 route de l' Eglise, Sainte-Foy, Quebec, G1V 4H5 (Canada)]. E-mail: jean.rodrigue@ec.gc.ca; Champoux, Louise [Environment Canada, Service canadien de la faune, 1141 route de l' Eglise, Sainte-Foy, Quebec, G1V 4H5 (Canada); Leclair, Daniel [Centre de recherche du Nunavik, Societe Makivik, C.P. 179, Kuujjuaq, Quebec, J0M 1C0 (Canada); Duchesne, Jean-Francois [Unite de recherche en sante publique du CHUQ, 945, avenue Wolfe, Sainte-Foy, Quebec, G1V 5B3 (Canada)

2007-06-15

Willow and rock ptarmigan were obtained from Northern Quebec. Willow ptarmigan were found to have mean cadmium concentrations of 179.7 {mu}g/g (dw) in the kidneys and 25.8 {mu}g/g (dw) in the liver; these levels were three times higher than those found in the rock ptarmigan. The cadmium levels in the ptarmigan were below the threshold above which adverse effects can be observed in birds. The difference between the two ptarmigan species in cadmium content is explained by the diet. A comparison of their diet showed that willow, which stores cadmium, is an important food resource for willow ptarmigan but not for rock ptarmigan. Because there is limited information available on the consumption of ptarmigan kidneys and liver by the Inuit, and the fact that this is a traditional way of life and provides nutritional benefits to the Inuit population, no consumption guidelines are proposed. - High levels of cadmium were found in ptarmigan in Northern Quebec. No consumption guidelines are proposed for the Inuit people.

Cadmium concentrations in tissues of willow ptarmigan (Lagopus lagopus) and rock ptarmigan (Lagopus muta) in Nunavik, Northern Quebec

International Nuclear Information System (INIS)

Rodrigue, Jean; Champoux, Louise; Leclair, Daniel; Duchesne, Jean-Francois

2007-01-01

Willow and rock ptarmigan were obtained from Northern Quebec. Willow ptarmigan were found to have mean cadmium concentrations of 179.7 μg/g (dw) in the kidneys and 25.8 μg/g (dw) in the liver; these levels were three times higher than those found in the rock ptarmigan. The cadmium levels in the ptarmigan were below the threshold above which adverse effects can be observed in birds. The difference between the two ptarmigan species in cadmium content is explained by the diet. A comparison of their diet showed that willow, which stores cadmium, is an important food resource for willow ptarmigan but not for rock ptarmigan. Because there is limited information available on the consumption of ptarmigan kidneys and liver by the Inuit, and the fact that this is a traditional way of life and provides nutritional benefits to the Inuit population, no consumption guidelines are proposed. - High levels of cadmium were found in ptarmigan in Northern Quebec. No consumption guidelines are proposed for the Inuit people

Isolation of Secondary Metabolites from the Roots of Salix Babylonica

Science.gov (United States)

Singh, Harpreet; Raturi, Rakesh; Badoni, P. P.

2017-08-01

Chemical examination of ethanolic extract of Salix babylonica, root, led to isolation of 2-(Hydroxymethyl) phenyl β-D-glucopyranoside(1) and 2-[(benzoyloxy)methyl]-4-hydroxyphenyl β-D-glucopyranoside 3-Benzoate (2)with previously known compounds β-Sitosterol, kaempferol 7-O-glucoside andapigenin 7-O-galactoside. Compounds 1and 2 had been isolated for the first time from this plant. The structures of the compounds had been elucidated with the help of spectral and chemical studies.

A New Flavonoid Glycoside from Salix denticulata Aerial Parts

Directory of Open Access Journals (Sweden)

Amita Bamola

2009-09-01

Full Text Available Abstract: A new flavonoid glycoside (1 has been isolated from the aerial parts of Salix denticulata (Salicaceae together with five known compounds, β-sitosterol, 2,6-dihydroxy- 4-methoxy acetophenone, eugenol-1-O-β-D-glucopyranoside, 1-O-β-D-(3’-benzoyl salicyl alcohol and luteolin-7-O-β-D-glucopyranosyl-(1-6-glucopyranoside. The structure of 1 was elucidated as 2’,5-dihydroxy-3’-methoxyflavone-7-O-β-D-glucopyranoside by means of chemical and spectral data including 2D NMR studies.

FIRST DIRECT EVIDENCE THAT BARIUM DWARFS HAVE WHITE DWARF COMPANIONS

International Nuclear Information System (INIS)

Gray, R. O.; McGahee, C. E.; Griffin, R. E. M.; Corbally, C. J.

2011-01-01

Barium II (Ba) stars are chemically peculiar F-, G-, and K-type objects that show enhanced abundances of s-process elements. Since s-process nucleosynthesis is unlikely to take place in stars prior to the advanced asymptotic giant branch (AGB) stage, the prevailing hypothesis is that each present Ba star was contaminated by an AGB companion which is now a white dwarf (WD). Unless the initial mass ratio of such a binary was fairly close to unity, the receiving star is thus at least as likely to be a dwarf as a giant. So although most known Ba stars appear to be giants, the hypothesis requires that Ba dwarfs be comparably plentiful and moreover that they should all have WD companions. However, despite dedicated searches with the IUE satellite, no WD companions have been directly detected to date among the classical Ba dwarfs, even though some 90% of those stars are spectroscopic binaries, so the contamination hypothesis is therefore presently in some jeopardy. In this paper, we analyze recent deep, near-UV and far-UV Galaxy Evolution Explorer (GALEX) exposures of four of the brightest of the class (HD 2454, 15360, 26367, and 221531), together with archived GALEX data for two newly recognized Ba dwarfs: HD 34654 and HD 114520 (which also prove to be spectroscopic binaries). The GALEX observations of the Ba dwarfs as a group show a significant far-UV excess compared to a control sample of normal F-type dwarfs. We suggest that this ensemble far-UV excess constitutes the first direct evidence that Ba dwarfs have WD companions.

Biomass power for rural development. Technical progress report, Phase 2, July 1--September 30, 1998

Energy Technology Data Exchange (ETDEWEB)

Neuhauser, E.

1999-01-01

The project undertaken by the Salix Consortium is a multi-phased, multi-partner endeavor. Phase 1 focused on initial development and testing of the technology and forging the necessary agreements to demonstrate commercial willow production. The Phase 1 objectives have been successfully completed: preparing final design plans for two utility pulverized coal boiler for 20 MW of biopower capacity; developing fuel supply plans for the project with a goal of establishing 365 ha (900 ac) of willow; obtaining power production commitments from the power companies for Phase 2; obtaining construction and environmental permits; and developing an experimental strategy for crop production and power generation improvements needed to assure commercial success. The R and D effort also addresses environmental issues pertaining to introduction of the willow energy system. Beyond those Phase 1 requirements, the Consortium has already successfully demonstrated cofiring at Greenidge Station and has initiated development of the required nursery capacity for acreage scale-up. In Phase 2 every aspect of willow production and power generation from willow biomass will be demonstrated. The ultimate objective of Phase 2 is to transition the work performed under the Biomass Power for Rural Development project into a thriving, self-supported energy crop enterprise.

With willows and poplars against the heavy metals

International Nuclear Information System (INIS)

Jaros, M.

2002-01-01

Special kinds of trees take out cadmium, lead and zinc from the soil, helping its rehabilitation in contaminated regions. A new method for soil rehabilitation (phytoremediation) based on plants is described. Special willows and poplars have the capability to extract as a sponge heavy metals from the soils and store them in their leaves. For example, they can uptake 700 times the amount of cadmium than the normal plants do. (nevyjel)

Recreational Appendix Report, Elm Fork Flood Control Project, Dallas and Denton Counties, Texas.

Science.gov (United States)

1973-05-01

Juniperus virginiana 2. Willow Salix nigra 3. Cottonwood Populus deltoides 4. Black Walnut Juglans migra 5. Pecan Carya illinoensis 6. Bur Oak...Maclura pomifera 12. Red Mulberry Morus rubra 13. Sycamore Platanus occidentailis 14. Red Haw Crataegus, sps. 15. Wild Plum Prunus mexicana 16. Mesquite...also provides a habitat for a number of mammals including: 1. Opossum Didelphis virginiana 2. Shrews Blarina brevicuada and Cryptotis parva 3. Raccoon

Threatened Vertebrate Species Occurring or Believed to Occur in the Floodplains of the Mississippi River between Cairo, Illinois, and Minneapolis, Minnesota, and of the Illinois Waterway between Grafton, Illinois, and Chicago, Illinois,

Science.gov (United States)

1975-01-01

heterophylla), and black willow (Salix nigra), with swamp white oak ( Quercus bicolor) and pin oak (p. valustri3) also important. Skorepa and Ozment (1968...of its original prairie habitat has seen destroyed. GREAT PLAINS RAT SNAKE Elaphe guttata emoryi (Baird and Girard) (Ill. -Rare) The Great Plains Rat...forficatus 119 F Clemmys guttata 41, 117 Elaphe guttata emoryi 49, 118 Cnemidophorus sexlineatus 43, 44, 117 Elassoma zonatum. 27, 114 Colinus virginianus

Environmental life cycle assessment of producing willow, alfalfa and straw from spring barley as feedstocks for bioenergy or biorefinery systems

DEFF Research Database (Denmark)

Parajuli, Ranjan; Knudsen, Marie Trydeman; Djomo, Sylvestre Njakou

2017-01-01

The current study aimed at evaluating potential environmental impacts for the production of willow, alfalfa and straw from spring barley as feedstocks for bioenergy or biorefinery systems. A method of Life Cycle Assessment was used to evaluate based on the following impact categories: Global...... and land occupation. Environmental impacts for straw were economically allocated from the impacts obtained for spring barley. The results obtained per ton dry matter showed a lower carbon footprint for willow and alfalfa compared to straw. It was due to higher soil carbon sequestration and lower N2O...... emissions. Likewise, willow and alfalfa had lower EP than straw. Straw had lowest NRE use compared to other biomasses. PFWTox was lower in willow and alfalfa compared to straw. A critical negative effect on soil quality was found with the spring barley production and hence for straw. Based on the energy...

White Dwarf Stars

OpenAIRE

Kepler, S. O.; Romero, Alejandra Daniela; Pelisoli, Ingrid; Ourique, Gustavo

2017-01-01

White dwarf stars are the final stage of most stars, born single or in multiple systems. We discuss the identification, magnetic fields, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identified white dwarf stars from 5000 to 39000. This number includes only white dwarf stars with log g >= 6.5 stars, i.e., excluding the Extremely Low Mass white dw...

Seasonal variation in radiocesium concentrations in three tree species

International Nuclear Information System (INIS)

Garten, C.R. Jr.; Briese, L.A.; Sharitz, R.R.; Gentry, J.B.

1975-01-01

Radiocesium concentrations in leaves and stems of black willow (Salix nigra), wax myrtle (Myrica cerifera), and tag alder (Alnus serrulata) trees inhabiting a floodplain contaminated by production-reactor effluents were measured over 1 year. In willow and myrtle trees, leaf radiocesium levels were highest in the spring and declined during the growing season; stem levels remained relatively unchanged or exhibited a slight increase. Seasonal changes in alder tree parts depended on the site examined. The relationship among component parts was essentially consistent across species and collecting sites in the summer. The radiocesium concentrations in order of rank were: roots greater than or equal to leaves greater than stems. Species differences in component-part radiocesium levels were dependent on the part sampled and the collecting site examined. Mean soil to plant-part concentration factors in summer ranged from 0.9 to 7.6, and species means across leaves, stems, and roots averaged 2.1, 3.8, and 6.2 for alder, willow, and myrtle trees, respectively

"The Wind in the Willows" and the Style of Romance

Science.gov (United States)

Gill, R. B.

2012-01-01

The style of Kenneth Grahame's "The Wind in the Willows" arises from an alternative vision and choice of values characteristic of romance. Romance seeks fulfillment beyond the consequences of everyday relationships and the constrictions of ordinary life. Causal relationships give way to lists of independent items, unmotivated outcomes, and…

Potential benefits of commercial willow Short Rotation Coppice (SRC) for farm-scale plant and invertebrate communities in the agri-environment

Energy Technology Data Exchange (ETDEWEB)

Rowe, Rebecca L.; Hanley, Mick E.; Goulson, Dave; Clarke, Donna J.; Doncaster, C. Patrick; Taylor, Gail [University of Southampton, Faculty of Natural and Environmental Sciences, Life Sciences Building, Southampton, S017 1BJ (United Kingdom)

2011-01-15

The cultivation of bioenergy crops (BECs) represents a significant land-use change in agri-environments, but their deployment has raised important issues globally regarding possible impacts on biodiversity. Few studies however, have systematically examined the effect of commercial scale bioenergy plantations on biodiversity in agri-ecosystems. In this study we investigate how the abundance and diversity of two key components of farmland biodiversity (ground flora and winged invertebrates) varied between mature willow Short Rotation Coppice (SRC) and two alternative land-use options (arable crops and set-aside land). Although the abundance of winged invertebrates was similar across all land-uses, taxonomic composition varied markedly. Hymenoptera and large Hemiptera (>5 mm) were more abundant in willow SRC than in arable or set-aside. Similarly although plant species richness was greater in set-aside, our data show that willow SRC supports a different plant community to the other land-uses, being dominated by competitive perennial species such as Elytrigia repens and Urtica dioica. Our results suggest that under current management practices a mixed farming system incorporating willow SRC can benefit native farm-scale biodiversity. In particular the reduced disturbance in willow SRC allows the persistence of perennial plant species, potentially providing a stable refuge and food sources for invertebrates. In addition, increased Hymenoptera abundance in willow SRC could potentially have concomitant effects on ecosystem processes, as many members of this Order are important pollinators of crop plants or otherwise fulfil an important beneficial role as predators or parasites of crop pests. (author)

Radiation of dwarf novae

International Nuclear Information System (INIS)

Bruch, A.

1987-01-01

The nature of dwarf novae with their components white dwarf star, cool star, accretion disk, boundary layer and hot spot is investigated. It is shown that very different physical states and processes occur in the components of dwarf novae. Spectroscopical and photometrical observations are carried out. For better understanding the radiation portions of the single dwarf novae components are separated from the total electromagnetic spectrum recieved from the dwarf novae. The model assumptions are compared with the observations and verified

Genetic variation in the endangered Southwestern Willow Flycatcher

Science.gov (United States)

Busch, Joseph; Miller, Mark P.; Paxton, E.H.; Sogge, M.K.; Keim, Paul

2000-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus) is an endangered Neotropical migrant that breeds in isolated remnants of dense riparian habitat in the southwestern United States. We estimated genetic variation at 20 breeding sites of the Southwestern Willow Flycatcher (290 individuals) using 38 amplified fragment length polymorphisms (AFLPs). Our results suggest that considerable genetic diversity exists within the subspecies and within local breeding sites. Statistical analyses of genetic variation revealed only slight, although significant, differentiation among breeding sites (Mantel's r = 0.0705, P UPGMA cluster analysis of the AFLP markers indicates that extensive gene flow has occurred among breeding sites. No one site stood out as being genetically unique or isolated. Therefore, the small level of genetic structure that we detected may not be biologically significant. Ongoing field studies are consistent with this conclusion. Of the banded birds that were resighted or recaptured in Arizona during the 1996 to 1998 breeding seasons, one-third moved between breeding sites and two-thirds were philopatric. Low differentiation may be the result of historically high rangewide diversity followed by recent geographic isolation of breeding sites, although observational data indicate that gene flow is a current phenomenon. Our data suggest that breeding groups of E. t. extimus act as a metapopulation.

A Natural History Summary and Survey Protocol for the Southwestern Willow Flycatcher

Science.gov (United States)

Sogge, Mark K.; ,; Ahlers, Darrell; ,; Sferra, Susan J.; ,

2010-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus) has been the subject of substantial research, monitoring, and management activity since it was listed as an endangered species in 1995. When proposed for listing in 1993, relatively little was known about the flycatcher's natural history, and there were only 30 known breeding sites supporting an estimated 111 territories rangewide (Sogge and others, 2003a). Since that time, thousands of presence/absences surveys have been conducted throughout the historical range of the flycatcher, and many studies of its natural history and ecology have been completed. As a result, the ecology of the flycatcher is much better understood than it was just over a decade ago. In addition, we have learned that the current status of the flycatcher is better than originally thought: as of 2007, the population was estimated at approximately 1,300 territories distributed among approximately 280 breeding sites (Durst and others, 2008a). Concern about the Southwestern Willow Flycatcher on a rangewide scale was brought to focus by Unitt (1987), who described declines in flycatcher abundance and distribution throughout the Southwest. E. t. extimus populations declined during the 20th century, primarily because of habitat loss and modification from activities, such as dam construction and operation, groundwater pumping, water diversions, and flood control. In 1991, the U.S. Fish and Wildlife Service (USFWS) designated the Southwestern Willow Flycatcher as a candidate category 1 species (U.S. Fish and Wildlife Service, 1991). In July 1993, the USFWS proposed to list E. t. extimus as an endangered species and to designate critical habitat under the Act (U.S. Fish and Wildlife Service, 1993). A final rule listing E. t. extimus as endangered was published in February 1995 (U.S. Fish and Wildlife Service, 1995); critical habitat was designated in 1997 (U.S. Fish and Wildlife Service, 1997). The USFWS Service released a Recovery Plan for

WHITE DWARF/M DWARF BINARIES AS SINGLE DEGENERATE PROGENITORS OF TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Wheeler, J. Craig

2012-01-01

Limits on the companions of white dwarfs in the single-degenerate scenario for the origin of Type Ia supernovae (SNe Ia) have gotten increasingly tight, yet igniting a nearly Chandrasekhar mass C/O white dwarf from a condition of near hydrostatic equilibrium provides compelling agreement with observed spectral evolution. The only type of non-degenerate stars that survive the tight limits, M V ∼> 8.4 on the SN Ia in SNR 0509-67.5 and M V ∼> 9.5 in the remnant of SN 1572, are M dwarfs. While M dwarfs are observed in cataclysmic variables, they have special properties that have not been considered in most work on the progenitors of SNe Ia: they have small but finite magnetic fields and they flare frequently. These properties are explored in the context of SN Ia progenitors. White dwarf/M dwarf pairs may be sufficiently plentiful to provide, in principle, an adequate rate of explosions even with slow orbital evolution due to magnetic braking or gravitational radiation. Even modest magnetic fields on the white dwarf and M dwarf will yield adequate torques to lock the two stars together, resulting in a slowly rotating white dwarf, with the magnetic poles pointing at one another in the orbital plane. The mass loss will be channeled by a 'magnetic bottle' connecting the two stars, landing on a concentrated polar area on the white dwarf. This enhances the effective rate of accretion compared to spherical accretion. Luminosity from accretion and hydrogen burning on the surface of the white dwarf may induce self-excited mass transfer. The combined effects of self-excited mass loss, polar accretion, and magnetic inhibition of mixing of accretion layers give possible means to beat the 'nova limit' and grow the white dwarf to the Chandrasekhar mass even at rather moderate mass accretion rates.

Evaluating the impact of three incentive programs on the economics of cofiring willow biomass with coal in New York State

International Nuclear Information System (INIS)

Tharakan, P.J.; Volk, T.A.; Lindsey, C.A.; Abrahamson, L.P.; White, E.H.

2005-01-01

Plantations of fast-growing willow shrubs are being promoted as a source quality biomass feedstock for bioenergy and bioproducts in New York State (NY). In the near-term, cofiring of the feedstock--in combination with other woody biomass--with coal in existing utility power boilers is considered to be the most promising conversion method for energy generation. Despite the clear technological viability and associated environmental benefits, cofiring of willow has not been widely adopted. The relatively high production cost of the willow feedstock, which is over twice that of coal, is the primary reason for this lack of interest. Taxes that account for some of the social costs of using coal and/or incentives that appropriate value for some of the social benefits of using willow are essential for eliminating most or the entire current price differential. This paper presents an integrated analysis of the economics of power generation from cofiring willow biomass feedstock with coal, from the perspective of the grower, aggregator and the power plant. Emphasis is placed on analyzing the relative impact of a green premium price, a closed-loop biomass tax credit, and payments to growers under the proposed Conservation Reserve Program (CRP) harvesting exemption policy. The CRP payments reduced the delivered cost of willow by 36-35%, to $1.90 GJ -1 and $1.70 GJ -1 , under current and increased yield conditions, respectively. These prices are still high, relative to coal. Other incentives are required to ensure commercial viability. The required levels of green premium price (0.4-1.0 cents kWh -1 ) and biomass tax credit (0.75-2.4 cents kWh -1 ) vary depending on whether the incentives were being applied by themselves or in combination, and whether current yield or potential increased yields were being considered. In the near term, cofiring willow biomass and coal can be an economically viable option for power generation in NY if the expected overall beneficial effects

Predictive models of biomass for poplar and willow. Short rotation coppice in the United Kingdom

Energy Technology Data Exchange (ETDEWEB)

Brewer, A.C.; Morgan, G.W.; Poole, E.J.; Baldwin, M.E.; Tubby, I. (Biometrics, Surveys and Statistics Division, Forest Research, Farnham (United Kingdom))

2007-07-01

A series of forty-nine experimental trials on short rotation coppice (SRC) were conducted throughout the United Kingdom using a selection of varieties of poplar and willow with the aim of evaluating their performance for wood fuel production under a representative range of UK conditions. Observations on the crops and on a range of site and climatic conditions during the growth of the crops were taken over two three-year cutting cycles. These observations were used to develop a suite of empirical models for poplar and willow SRC growth and yield from which systems were constructed to provide a- priori predictions of biomass yield for any site in the UK with known characteristics (predictive yield models), and estimates of biomass yield from a standing crop (standing biomass models). The structure of the series of field trials and the consequent approach and methodology used in the construction of the suite of empirical models are described, and their use in predicting biomass yields of poplar and willow SRC is discussed. (orig.)

FORMATION OF ULTRA-COMPACT BLUE DWARF GALAXIES AND THEIR EVOLUTION INTO NUCLEATED DWARFS

International Nuclear Information System (INIS)

Bekki, Kenji

2015-01-01

We propose that there is an evolutionary link between ultra-compact blue dwarf galaxies (UCBDs) with active star formation and nucleated dwarfs based on the results of numerical simulations of dwarf–dwarf merging. We consider the observational fact that low-mass dwarfs can be very gas-rich, and thereby investigate the dynamical and chemical evolution of very gas-rich, dissipative dwarf–dwarf mergers. We find that the remnants of dwarf–dwarf mergers can be dominated by new stellar populations formed from the triggered starbursts and consequently can have blue colors and higher metallicities (Z ∼ [0.2–1]Z ⊙ ). We also find that the remnants of these mergers can have rather high mass densities (10 4 M ⊙ pc −3 ) within the central 10 pc and small half-light radii (40−100 pc). The radial stellar structures of some merger remnants are similar to those of nucleated dwarfs. Star formation can continue in nuclear gas disks (R < 100 pc) surrounding stellar galactic nuclei (SGNs) so that the SGNs can finally have multiple stellar populations with different ages and metallicities. These very compact blue remnants can be identified as UCBDs soon after merging and as nucleated dwarfs after the young stars fade. We discuss these results in the context of the origins of metal-rich ultra-compact dwarfs and SGNs

FORMATION OF ULTRA-COMPACT BLUE DWARF GALAXIES AND THEIR EVOLUTION INTO NUCLEATED DWARFS

Energy Technology Data Exchange (ETDEWEB)

Bekki, Kenji [ICRAR, M468, The University of Western Australia 35 Stirling Highway, Crawley Western Australia, 6009 (Australia)

2015-10-10

We propose that there is an evolutionary link between ultra-compact blue dwarf galaxies (UCBDs) with active star formation and nucleated dwarfs based on the results of numerical simulations of dwarf–dwarf merging. We consider the observational fact that low-mass dwarfs can be very gas-rich, and thereby investigate the dynamical and chemical evolution of very gas-rich, dissipative dwarf–dwarf mergers. We find that the remnants of dwarf–dwarf mergers can be dominated by new stellar populations formed from the triggered starbursts and consequently can have blue colors and higher metallicities (Z ∼ [0.2–1]Z{sub ⊙}). We also find that the remnants of these mergers can have rather high mass densities (10{sup 4} M{sub ⊙} pc{sup −3}) within the central 10 pc and small half-light radii (40−100 pc). The radial stellar structures of some merger remnants are similar to those of nucleated dwarfs. Star formation can continue in nuclear gas disks (R < 100 pc) surrounding stellar galactic nuclei (SGNs) so that the SGNs can finally have multiple stellar populations with different ages and metallicities. These very compact blue remnants can be identified as UCBDs soon after merging and as nucleated dwarfs after the young stars fade. We discuss these results in the context of the origins of metal-rich ultra-compact dwarfs and SGNs.

New Light on Dark Stars Red Dwarfs, Low-Mass Stars, Brown Dwarfs

CERN Document Server

Reid, I. Neill

2005-01-01

There has been very considerable progress in research into low-mass stars, brown dwarfs and extrasolar planets during the past few years, particularly since the fist edtion of this book was published in 2000. In this new edtion the authors present a comprehensive review of both the astrophysical nature of individual red dwarf and brown dwarf stars and their collective statistical properties as an important Galactic stellar population. Chapters dealing with the observational properies of low-mass dwarfs, the stellar mass function and extrasolar planets have been completely revised. Other chapters have been significantly revised and updated as appropriate, including important new material on observational techniques, stellar acivity, the Galactic halo and field star surveys. The authors detail the many discoveries of new brown dwarfs and extrasolar planets made since publication of the first edition of the book and provide a state-of-the-art review of our current knowledge of very low-mass stars, brown dwarfs a...

EFFECT OF TEMPERATURE ON THE BIOLOGY OF TUBEROLACHNUS SALIGNUS (GMELIN (STERNORRHYNCHA: APHIDIDAE ON (SALIX ALBA

Directory of Open Access Journals (Sweden)

Nıhal ÖZDER

2008-07-01

Full Text Available The development time, survivoship and reproduction of Tuberolachnus salignus (Gmelin( Lachninae: Lachnini were studied on Salix alba at fi ve constant temperatures (17.5°C, 20°C, 22.5°C, 25°C and 27.5°C . The developmental time of immature stages ranged from 17.00 days at 17.5°C to 12.21 days at 25°C on Salix alba. The total percentage of survivorship of immature stages varied from 50% and 70% 17.5°C -20°C on S. alba. The largest r m valueoccurred with 0.2540 at 20°C on S. alba. The mean generation time of the population ranged from 13.595 days at 22.5°C to 19.60 days at 17.5°C on S. alba. The optimal temperature for Tuberolachnus salignus was 20°C.

Extremely shallow spawning of perch (Perca fluviatilis L.): the roles of sheltered bays, dense semi-terrestrial vegetation and low visibility in deeper water

Czech Academy of Sciences Publication Activity Database

Čech, Martin; Peterka, Jiří; Říha, Milan; Vejřík, Lukáš; Jůza, Tomáš; Kratochvíl, Michal; Draštík, Vladislav; Muška, Milan; Znachor, Petr; Kubečka, Jan

2012-01-01

Roč. 406, December (2012), 09p1-09p12 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GA206/06/1371; GA ČR(CZ) GP206/09/P266; GA MZe(CZ) QH81046 Institutional support: RVO:60077344 Keywords : Římov Reservoir * Chabařovice Lake * SCUBA diving * Reed Canarygrass Phalaris arudinacea * Goat Willow Salix caprea * egg strands Subject RIV: EG - Zoology Impact factor: 0.467, year: 2012

Cultural Resources Survey and Archeological Inventory of the Proposed Carrollton Revetment Project, Orleans Parish, Louisiana, Phase 1. Volume 1 of 2

Science.gov (United States)

2004-11-01

The proposed project area has a humid sub- kin ash (Fraxinus profunda ), green ash (Frax- tropical climate with prevailing southerly winds. inus...leans on June 27, 1967, is 39’ (1020 F) (Magill Salix nigra Black willow 1990:6; Trahan 1989; Peters and Beall 2002). Fraxinus profunda Pumpkin ash...In addition, the Internet radio show "New bait blue glass jar embossed "BROM... /EM...," Orleans Nostalgia" references radio advertise- refers to a

The root anchorage ability of Salix alba var. tristis using a pull-out test

African Journals Online (AJOL)

user

2011-11-21

Nov 21, 2011 ... In the last few years, Beijing Forestry University (China) and the University of Natural Resources and applied Life. Sciences (Austria) have examined the suitabilities and capabilities of soil bioengineering techniques under the local condition of Beijing. One of the plant species used was Salix alba var. tristis.

Distinguishing CDM dwarfs from SIDM dwarfs in baryonic simulations

Science.gov (United States)

Strickland, Emily; Fitts, Alex B.; Boylan-Kolchin, Michael

2017-06-01

Dwarf galaxies in the nearby Universe are the most dark-matter-dominated systems known. They are therefore natural probes of the nature of dark matter, which remains unknown. Our collaboration has performed several high-resolution cosmological zoom-in simulations of isolated dwarf galaxies. We simulate each galaxy in standard cold dark matter (ΛCDM) as well as self-interacting dark matter (SIDM, with a cross section of σ/m ~ 1 cm2/g), both with and without baryons, in order to identify distinguishing characteristics between the two. The simulations are run using GIZMO, a meshless-finite-mass hydrodynamical code, and are part of the Feedback in Realistic Environments (FIRE) project. By analyzing both the global properties and inner structure of the dwarfs in varying dark matter prescriptions, we provide a side-by-side comparison of isolated, dark-matter-dominated galaxies at the mass scale where differences in the two models of dark matter are thought to be the most obvious. We find that the edge of classical dwarfs and ultra-faint dwarfs (at stellar masses of ~105 solar masses) provides the clearest window for distinguishing between the two theories. At these low masses, our SIDM galaxies have a cored inner density profile, while their CDM counterparts have “cuspy” centers. The SIDM versions of each galaxy also have measurably lower stellar velocity dispersions than their CDM counterparts. Future observations of ultra faint dwarfs with JWST and 30-m telescopes will be able to discern whether such alternate theories of dark matter are viable.

THE BROWN DWARF KINEMATICS PROJECT (BDKP). III. PARALLAXES FOR 70 ULTRACOOL DWARFS

International Nuclear Information System (INIS)

Faherty, Jacqueline K.; Shara, Michael M.; Cruz, Kelle L.; Burgasser, Adam J.; Walter, Frederick M.; Van der Bliek, Nicole; West, Andrew A.; Vrba, Frederick J.; Anglada-Escudé, Guillem

2012-01-01

We report parallax measurements for 70 ultracool dwarfs (UCDs) including 11 late-M, 32 L, and 27 T dwarfs. In this sample, 14 M and L dwarfs exhibit low surface gravity features, 6 are close binary systems, and 2 are metal-poor subdwarfs. We combined our new measurements with 114 previously published UCD parallaxes and optical-mid-IR photometry to examine trends in spectral-type/absolute magnitude, and color-color diagrams. We report new polynomial relations between spectral type and M JHK . Including resolved L/T transition binaries in the relations, we find no reason to differentiate between a 'bright' (unresolved binary) and a 'faint' (single source) sample across the L/T boundary. Isolating early T dwarfs, we find that the brightening of T0-T4 sources is prominent in M J where there is a [1.2-1.4] mag difference. A similar yet dampened brightening of [0.3-0.5] mag happens at M H and a plateau or dimming of [–0.2 to –0.3] mag is seen in M K . Comparison with evolutionary models that vary gravity, metallicity, and cloud thickness verifies that for L into T dwarfs, decreasing cloud thickness reproduces brown dwarf near-IR color-magnitude diagrams. However we find that a near constant temperature of 1200 ±100 K along a narrow spectral subtype of T0-T4 is required to account for the brightening and color-magnitude diagram of the L-dwarf/T-dwarf transition. There is a significant population of both L and T dwarfs which are red or potentially 'ultra-cloudy' compared to the models, many of which are known to be young indicating a correlation between enhanced photospheric dust and youth. For the low surface gravity or young companion L dwarfs we find that 8 out of 10 are at least [0.2-1.0] mag underluminous in M JH and/or M K compared to equivalent spectral type objects. We speculate that this is a consequence of increased dust opacity and conclude that low surface gravity L dwarfs require a completely new spectral-type/absolute magnitude polynomial for analysis.

THE BROWN DWARF KINEMATICS PROJECT (BDKP). III. PARALLAXES FOR 70 ULTRACOOL DWARFS

Energy Technology Data Exchange (ETDEWEB)

Faherty, Jacqueline K.; Shara, Michael M.; Cruz, Kelle L. [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10034 (United States); Burgasser, Adam J. [Center of Astrophysics and Space Sciences, Department of Physics, University of California, San Diego, CA 92093 (United States); Walter, Frederick M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Van der Bliek, Nicole [CTIO/National Optical Astronomy Observatory (Chile); West, Andrew A. [Department of Astronomy, Boston University, 725 Commonwealth Ave Boston, MA 02215 (United States); Vrba, Frederick J. [US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002 (United States); Anglada-Escude, Guillem, E-mail: jfaherty@amnh.org [Department of Terrestrial Magnetism, Carnegie Institution of Washington 5241 Broad Branch Road, NW, Washington, DC 20015 (United States)

2012-06-10

We report parallax measurements for 70 ultracool dwarfs (UCDs) including 11 late-M, 32 L, and 27 T dwarfs. In this sample, 14 M and L dwarfs exhibit low surface gravity features, 6 are close binary systems, and 2 are metal-poor subdwarfs. We combined our new measurements with 114 previously published UCD parallaxes and optical-mid-IR photometry to examine trends in spectral-type/absolute magnitude, and color-color diagrams. We report new polynomial relations between spectral type and M{sub JHK}. Including resolved L/T transition binaries in the relations, we find no reason to differentiate between a 'bright' (unresolved binary) and a 'faint' (single source) sample across the L/T boundary. Isolating early T dwarfs, we find that the brightening of T0-T4 sources is prominent in M{sub J} where there is a [1.2-1.4] mag difference. A similar yet dampened brightening of [0.3-0.5] mag happens at M{sub H} and a plateau or dimming of [-0.2 to -0.3] mag is seen in M{sub K} . Comparison with evolutionary models that vary gravity, metallicity, and cloud thickness verifies that for L into T dwarfs, decreasing cloud thickness reproduces brown dwarf near-IR color-magnitude diagrams. However we find that a near constant temperature of 1200 {+-}100 K along a narrow spectral subtype of T0-T4 is required to account for the brightening and color-magnitude diagram of the L-dwarf/T-dwarf transition. There is a significant population of both L and T dwarfs which are red or potentially 'ultra-cloudy' compared to the models, many of which are known to be young indicating a correlation between enhanced photospheric dust and youth. For the low surface gravity or young companion L dwarfs we find that 8 out of 10 are at least [0.2-1.0] mag underluminous in M{sub JH} and/or M{sub K} compared to equivalent spectral type objects. We speculate that this is a consequence of increased dust opacity and conclude that low surface gravity L dwarfs require a completely new

Activity and Kinematics of White Dwarf-M Dwarf Binaries from the SUPERBLINK Proper Motion Survey

International Nuclear Information System (INIS)

Skinner, Julie N.; Morgan, Dylan P.; West, Andrew A.; Lépine, Sébastien; Thorstensen, John R.

2017-01-01

We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV–optical–IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use H α chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population.

Activity and Kinematics of White Dwarf-M Dwarf Binaries from the SUPERBLINK Proper Motion Survey

Energy Technology Data Exchange (ETDEWEB)

Skinner, Julie N. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Morgan, Dylan P.; West, Andrew A. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Lépine, Sébastien [Department of Physics and Astronomy, Georgia State University, 25 Park Place NE, Atlanta, GA, 30303 (United States); Thorstensen, John R., E-mail: jskinner@bu.edu [Department of Physics and Astronomy, 6127 Wilder Laboratory, Dartmouth College, Hanover, NH 03755 (United States)

2017-09-01

We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV–optical–IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use H α chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population.

Production of Probiotic Drink Using Pussy willow and Echium amoenum Extracts

Directory of Open Access Journals (Sweden)

Mahbobeh Eksiri

2017-06-01

Full Text Available Background and Objective: Nowadays, due to the lack of lactose and cholesterol, demand for consumption of non-dairy probiotic products is increasing. Probiotic drinks mixed with medicinal plant have great beneficial effect on human health. The main problems of non-dairy probiotic drinks are lack of nutrients for the growth of probiotics and bad taste of the product. The aim of this study was to produce a probiotic medicinal plant drink with favorable physicochemical, viability and sensory properties.Material and Methods: Probiotic drink prepared by Pussy willow and Echium amoenum extract (0.5 % w v-1, for each extract or together, Lactobacillus casei and Lactobacillus rhamnosus (108 CFU ml-1, individually and their combination. Glucose and whey powder (0.2% were used as a source of nutrition for the probiotics, and apple juice (20 and 30% was added to improve the taste of drink. The level of glucose was adjusted to reach the brix of 13 g100 g-1. Ascorbic acid (0.05% was used to improve micro-aerophilic conditions. The pH, acidity, glucose and viability of probiotic bacteria as well as the sensory properties of the prepared drink were investigated during 28 days at 4°C.Results and Conclusion: Based on the results, the treatment containing L. casei, Pussy willow, Echium amoenum and 30% apple juice due to the highest probiotic viability and the treatment containing Lactobacillus rhamnosus, Pussy willow, Echium amoenum and 30% apple juice because of higher total acceptance score, proper pH and acidity values were selected as the best treatments.Conflict of interest: The authors declare no conflict of interest.

Uptake of cadmium from hydroponic solutions by willows (Salix spp ...

African Journals Online (AJOL)

DR. NJ TONUKARI

2011-11-16

Nov 16, 2011 ... which indicated that cadmium uptake across the plasma membrane was ... to cadmium pollution in water-soil-plant systems because .... plants were separated into roots and shoots, blotted dry with paper tissue .... Analysis of the kinetic constants for cadmium uptake ..... proteins (Welch and Norvell, 1999).

Uptake, removal, accumulation, and phytotoxicity of 4-chlorophenol in willow trees

DEFF Research Database (Denmark)

Ucisik, Ahmed Süheyl; Trapp, Stefan

2008-01-01

of implementing phytoremediation as a treatment method for 4-CP contamination was investigated. Willows were exposed to 4-CP levels ≤79.9 mg/L in hydroponic solution. The transpiration of the trees was used to determine toxic effects. Almost no inhibition of transpiration was detected at concentrations ≥15 mg...

Activity and Kinematics of White Dwarf-M Dwarf Binaries from the SUPERBLINK Proper Motion Survey

Science.gov (United States)

Skinner, Julie N.; Morgan, Dylan P.; West, Andrew A.; Lépine, Sébastien; Thorstensen, John R.

2017-09-01

We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV-optical-IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use Hα chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population. Based on observations obtained at the MDM Observatory operated by Dartmouth College, Columbia University, The Ohio State University, and the University of Michigan.

Arbuscular mycorrhizal fungi associated with Populus-Salix stands in a semiarid riparian ecosystem

Science.gov (United States)

Beauchamp, Vanessa B.; Stromberg, J.C.; Stutz, J.C.

2006-01-01

??? This study examined the activity, species richness, and species composition of the arbuscular mycorrhizal fungal (AMF) community of Populus-Salix stands on the Verde River (Arizona, USA), quantified patterns of AMF richness and colonization along complex floodplain gradients, and identified environmental variables responsible for structuring the AMF community. ??? Samples from 61 Populus-Salix stands were analyzed for AMF and herbaceous composition, AMF colonization, gravimetric soil moisture, soil texture, per cent organic matter, pH, and concentrations of nitrate, bicarbonate phosphorus and exchangeable potassium. ??? AMF species richness declined with stand age and distance from and elevation above the channel and was positively related to perennial species cover and richness and gravimetric soil moisture. Distance from and elevation above the active channel, forest age, annual species cover, perennial species richness, and exchangeable potassium concentration all played a role in structuring the AMF community in this riparian area. ??? Most AMF species were found across a wide range of soil conditions, but a subset of species tended to occur more often in hydric areas. This group of riparian affiliate AMF species includes several not previously encountered in the surrounding Sonoran desert. ?? New Phytologist (2006).

37 NEW T-TYPE BROWN DWARFS IN THE CANADA-FRANCE BROWN DWARFS SURVEY

International Nuclear Information System (INIS)

Albert, Loic; Artigau, Etienne; Delorme, Philippe; Reyle, Celine; Forveille, Thierry; Delfosse, Xavier; Willott, Chris J.

2011-01-01

The Canada-France Brown Dwarfs Survey is an i'- and z'-band survey realized with MegaCam at the Canada-France-Hawaii Telescope that covers a surface area of 780 deg 2 . Image analysis is now completed while J-band follow-up campaigns are ∼90% done. The survey identified about 70 T dwarf candidates, of which 43 now have near-infrared spectra obtained with NIRI and GNIRS at Gemini and ISAAC at the Very Large Telescope. Six of these were previously published and we present here the 37 new discoveries, all T dwarfs. They range from T0 to T8.5 with four being of type T7 or later. Both newly identified T8 dwarfs are possibly high log (g) massive brown dwarfs of thin disk age. One T4.5 dwarf shows signs of sub-metallicity. We present proper motions and near-infrared photometry, and discuss about the most peculiar/interesting objects in some details.

Mid-Infrared Observations of the White Dwarf Brown Dwarf Binary GD 1400

OpenAIRE

Farihi, J.; Zuckerman, B.; Becklin, E. E.

2005-01-01

Fluxes are measured for the DA white dwarf plus brown dwarf pair GD 1400 with the Infrared Array Camera on the {\\em Spitzer Space Telescope}. GD 1400 displays an infrared excess over the entire $3-8\\mu$m region consistent with the presence of a mid- to late-type L dwarf companion. A discussion is given regarding current knowledge of this unique system.

Stark Broadening and White Dwarfs

Directory of Open Access Journals (Sweden)

Dimitrijević Milan S.

2011-12-01

Full Text Available White dwarf and pre-white dwarfs are the best types of stars for the application of Stark broadening research results in astrophysics, since in the atmospheres of these stars physical conditions are very favorable for this line broadening mechanism - in hot hydrogen-deficient white dwarfs and pre-white dwarfs Teff = 75 000–180 000 K and log g = 5.5–8 [cgs]. Even for much cooler DA and DB white dwarfs with the typical effective temperatures 10 000-20 000 K, Stark broadening is usually the dominant broadening mechanism. In this review, Stark broadening in white dwarf spectra is considered, and the attention is drawn to the STARK-B database (http://stark-b.obspm.fr/, containing the parameters needed for analysis and synthesis of white dwarf spectra, as well as for the collective efforts to develop the Virtual Atomic and Molecular Data Center.

Late-glacial atmospheric CO{sub 2} reconstructions from western Norway using fossil leaves

Energy Technology Data Exchange (ETDEWEB)

Birks, H H; Birks, H J.B. [Sheffield Univ. (United Kingdom). Dept. of Animal and Plant Sciences; Beerling, D J; Woodward, F I [Bergen Univ. (Norway). Botanical Inst.

1996-12-31

Analyses of air bubbles trapped in Antarctic ice-cores have shown that atmospheric CO{sub 2} concentrations are 180-200 ppmv during glacial periods, and ca. 280 ppmv during interglacials, including the Holocene. The change from glacial to Holocene concentrations occurred steadily over ca. 5000 years, slightly lagging the temperature increase inferred from {delta}{sup 18}. Antarctic ice cores lack fine time resolution over the late-glacial/early Holocene period 12-9000 {sup 14}C yr BP, that includes the Younger Dryas cold oscillation. The stomatal density on leaves is inversely proportional to the concentration of atmospheric CO{sub 2}. A late glacial sequence at Kraakenes, western Norway, contains well-preserved Salix herbacea (dwarf willow) leaves, dated from 11700-9600 {sup 14}C yr BP. If the stomatal density is measured on the fossil leaves, a calibration derived from the relationship of stomatal density of modern material of the same species to known CO{sub 2} concentrations can be used to reconstruct CO{sub 2} concentrations of the past. Because of the decadal time-resolution available at Kraakenes through the late-glacial and early Holocene, a detailed record of CO{sub 2} concentrations can be reconstructed over this period, that will complement the ice core record. (author)

Late-glacial atmospheric CO{sub 2} reconstructions from western Norway using fossil leaves

Energy Technology Data Exchange (ETDEWEB)

Birks, H.H.; Birks, H.J.B. [Sheffield Univ. (United Kingdom). Dept. of Animal and Plant Sciences; Beerling, D.J.; Woodward, F.I. [Bergen Univ. (Norway). Botanical Inst.

1995-12-31

Analyses of air bubbles trapped in Antarctic ice-cores have shown that atmospheric CO{sub 2} concentrations are 180-200 ppmv during glacial periods, and ca. 280 ppmv during interglacials, including the Holocene. The change from glacial to Holocene concentrations occurred steadily over ca. 5000 years, slightly lagging the temperature increase inferred from {delta}{sup 18}. Antarctic ice cores lack fine time resolution over the late-glacial/early Holocene period 12-9000 {sup 14}C yr BP, that includes the Younger Dryas cold oscillation. The stomatal density on leaves is inversely proportional to the concentration of atmospheric CO{sub 2}. A late glacial sequence at Kraakenes, western Norway, contains well-preserved Salix herbacea (dwarf willow) leaves, dated from 11700-9600 {sup 14}C yr BP. If the stomatal density is measured on the fossil leaves, a calibration derived from the relationship of stomatal density of modern material of the same species to known CO{sub 2} concentrations can be used to reconstruct CO{sub 2} concentrations of the past. Because of the decadal time-resolution available at Kraakenes through the late-glacial and early Holocene, a detailed record of CO{sub 2} concentrations can be reconstructed over this period, that will complement the ice core record. (author)

Conversion from cropland to short rotation coppice willow and poplar: Accumulation of soil organic carbon

Science.gov (United States)

Georgiadis, Petros; Stupak, Inge; Vesterdal, Lars; Raulund-Rasmussen, Karsten

2015-04-01

Increased demand for bioenergy has intensified the production of Short Rotation Coppice (SRC) willow and poplar in temperate zones. We used a combined chronosequence and paired plot approach to study the potential of SRC willow and poplar stands to increase the soil carbon stock compared to stocks of the previous arable land-use. The study focused on well-drained soils. We sampled soil from 30 SRC stands in Denmark and southern Sweden including soils from their adjacent arable fields. The 18 willow and 12 poplar stands formed a chronosequence ranging between 4 and 29 years after conversion. The soil was sampled both with soil cores taken by fixed depths of 0-5, 5-10, 10-15, 15-25, and 25-40 cm and by genetic horizons from soil pits to 1m depth. The aim of the study was to estimate the difference and the ratio between soil carbon contents of the SRC and annual crop land and analyze the results as a chronosequence to examine the effect of age after conversion on the difference. Covariates such as soil type, fertilization type and harvest frequency were also taken into account. Preliminary results suggest an overall increase in carbon stocks over time with average accumulation rates ranging from 0.25 to 0.4 Mg ha-1 yr-1 in willow and poplar stands. Poplar stands had higher rates of C gain, probably due to less frequent harvesting. The differences in carbon between the SRC and the paired cropland were initially negative but changed to positive over time, implying loss of carbon after conversion and a later gain in soil carbon with stand age. Pairwise differences ranged from -25 Mg C ha-1 to 37 Mg C ha-1 for the top 40 cm. The carbon stock ratio of the SRC stand to the arable land was estimated to minimize the effect of site-related factors. The results of this analysis suggested that the ratio increased significantly with age after conversion for the top 10 cm of the soil, both for poplar and willow. A slight increase with age was also noticed at the deeper depths, but

Sorption of lipophilic organic compunds to wood and implications for their environmental fate

DEFF Research Database (Denmark)

Trapp, Stefan; Miglioranza, S.B.; Mosbæk, Hans

2001-01-01

The sorption from water to wood (KWood) of 10 organic chemicals (logKOW, 1.48-6.20) was experimentally determined for oak (Quercus robur) and basket willow (Salix viminalis). Linear regression yielded log KWood ) -0.27 (( 0.25) + 0.632 (( 0.063)log KOW for oak (r ) 0.90, n ) 27) and log KWood ) -...... time. If metabolism inside the stem occurs, wood can serve as a “safe sink” for environmental chemicals. This might be of use in phytoremediation....

Dwarf Mice and Aging.

Science.gov (United States)

Masternak, Michal M; Darcy, Justin; Victoria, Berta; Bartke, Andrzej

2018-01-01

Dwarf mice have been studied for many decades, however, the focus of these studies shifted in 1996 when it was shown by Brown-Borg and her coworkers that Ames dwarf (Prop1 df ) mice are exceptionally long-lived. Since then, Snell dwarf (Pit1 dw ) and growth hormone receptor knockout (GHR-KO, a.k.a. Laron dwarf) mice were also shown to be exceptionally long-lived, presumably due to their growth hormone (GH)-deficiency or -resistance, respectively. What is of equal importance in these dwarf mice is their extended health span, that is, these animals have a longer period of life lived free of frailty and age-related diseases. This review article focuses on recent studies conducted in these dwarf mice, which concerned brown and white adipose tissue biology, microRNA (miRNA) profiling, as well as early-life dietary and hormonal interventions. Results of these studies identify novel mechanisms linking reduced GH action with extensions of both life span and health span. Copyright © 2017. Published by Elsevier Inc.

Benchmarking Brown Dwarf Models With a Non-irradiated Transiting Brown Dwarf in Praesepe

Science.gov (United States)

Beatty, Thomas; Marley, Mark; Line, Michael; Gizis, John

2018-05-01

We wish to use 9.4 hours of Spitzer time to observe two eclipses, one each at 3.6um and 4.5um, of the transiting brown dwarf AD 3116b. AD 3116b is a 54.2+/-4.3 MJ, 1.08+/-0.07 RJ object on a 1.98 day orbit about a 3200K M-dwarf. Uniquely, AD 3116 and its host star are both members of Praesepe, a 690+/-60 Myr old open cluster. AD 3116b is thus one of two transiting brown dwarfs for which we have a robust isochronal age that is not dependent upon brown dwarf evolutionary models, and the youngest brown dwarf for which this is the case. Importantly, the flux AD 3116b receives from its host star is only 0.7% of its predicted internal luminosity (Saumon & Marley 2008). This makes AD 3116b the first known transiting brown dwarf that simultaneously has a well-defined age, and that receives a negligible amount of external irradiation, and a unique laboratory to test radius and luminosity predictions from brown dwarf evolutionary models. Our goal is to measure the emission from the brown dwarf. AD 3116b should have large, 25 mmag, eclipse depths in the Spitzer bandpasses, and we expect to measure them with a precision of +/-0.50 mmag at 3.6um and +/-0.54 mmag at 4.5um. This will allow us to make measure AD 3116b?s internal effective temperature to +/-40K. We will also use the upcoming Gaia DR2 parallaxes to measure AD 3116b's absolute IRAC magnitudes and color, and hence determine the cloud properties of the atmosphere. As the only known brown dwarf with an independently measured mass, radius, and age, Spitzer measurements of AD 3116b's luminosity and clouds will provide a critical benchmark for brown dwarf observation and theory.

Ecology of tidal freshwater forests in coastal deltaic Louisiana and northeastern South Carolina: Chapter 9

Science.gov (United States)

Conner, William H.; Krauss, Ken W.; Doyle, Thomas W.

2007-01-01

were converted to tidal rice fields in the 1700s (Porcher 1995). Canopy members of the present day forests include baldcypress, water tupelo, swamp tupelo (N. biflora Walt.), red maple, and Carolina ash (Fraxinus caroliniana Miller). Subcanopy and shrub species include Virginia sweetspire (Itea virginica L.), dwarf palmetto (Sabal minor (Jacquin) Pers.), coastal plain willow (Salix caroliniana Michx.), redbay, and water-elm (Planera aquatica Gmel.).

Indução de calos friáveis em explantes foliares de Salix (Salyx humboldtiana Willd Induction of friable callus in leaf explants of Salix (Salyx humboldtiana Willd

Directory of Open Access Journals (Sweden)

Breno Régis Santos

2005-06-01

Full Text Available O salix é uma árvore ornamental adaptada a terrenos úmidos, sendo considerada uma espécie importante para a recomposição de áreas ciliares degradadas. A madeira pode ser empregada na indústria em geral. Apesar de produzir grande quantidade de sementes, estas não possuem alta percentagem de germinação. O presente trabalho teve como objetivo realizar o estabelecimento in vitro de salix através da indução e formação de calos friáveis em explantes foliares, visando a uma posterior regeneração de plantas para a propagação massal desta espécie. Explantes foliares foram inoculados em meio de cultura MS (MURASHIGE & SKOOG, 1962, acrescido de diferentes concentrações de ácido 2,4-diclorofenoxiacético (0; 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 e 12,0mg L-1 e combinações entre ácido naftalenoacético e benzilaminopurina, ambos em concentrações de 0,0; 1,0; 2,0; 4,0; 6,0 e 8,0mg L-1. Os resultados demonstram que explantes inoculados na ausência de reguladores de crescimento não apresentam a formação de calos friáveis. Significativa produção de calos friáveis (90% é obtida utilizando-se 6,0mg L-1 de ácido 2,4-diclorofenoxiacético. A utilização de concentração individual de ácido naftalenoacético ou benzilaminopurina, além de induzir a calogênese também foi capaz de promover rizogênese.Salix is an ornamental tree adapted to humid soils being considered an important species used in depleted areas. Its wood may be used in all kinds of industries. Although the production of seeds is large, the germination is reduced. The objective of this work was to establish salix in vitro through the induction and formation of friable callus of leaf explants to provide future regeneration of plants for mass propagation of the species. Leaf explants were inoculated in MS medium (MURASHIGE & SKOOG, 1962 supplemented with different concentrations of 2-4-diclorofenoxiacetic acid (0; 1.0; 2.0; 4.0; 6.0; 8.0 and 12.0mg L-1 and combinations

Effects of summer and winter harvesting on element phytoextraction efficiency of Salix and Populus clones planted on contaminated soil.

Science.gov (United States)

Kubátová, Pavla; Száková, Jiřina; Břendová, Kateřina; Kroulíková-Vondráčková, Stanislava; Mercl, Filip; Tlustoš, Pavel

2018-04-16

The clones of fast-growing trees (FGTs) were investigated for phytoextraction of soil contaminated with risk elements (REs), especially Cd, Pb, and Zn. As a main experimental factor, the potential effect of biomass harvesting time was assessed. The field experiment with two Salix clones (S1 - (Salix schwerinii × Salix viminalis) × S. viminalis, S2 - S. × smithiana) and two Populus clones (P1 - Populus maximowiczii × Populus nigra, P2 - P. nigra) was established in April 2009. Shoots of all clones were first harvested in February 2012. After two further growing seasons, the first half of the trees was harvested in September 2013 before leaf fall (summer harvest) and the second half in February 2014 (winter harvest). Remediation factors (RFs) for all clones and all REs (except Pb for clone S1) were higher in the summer harvest. The highest annual RFs for Cd and for Zn (1.34 and 0.67%, respectively) were found for clone S2 and were significantly higher than other clones. Although no increased mortality of trees harvested in the summer was detected in the following season, the effect of summer harvesting on the phytoextraction potential of FGTs clones should be investigated in long-term studies.

The level of invasion of the willow-poplar floodplain forests of Danube lowland

International Nuclear Information System (INIS)

Botkova, K.; Petrasova, K.

2015-01-01

Invasions of neophyte plant species are considered as one of the major threats to the diversity of natural ecosystems including floodplain forests. The aims of our study were to find out if there is a significant increase in the number and cover of neophyte species in the willow-poplar floodplain forests of Danube lowland over time. The level of invasion of the willow-poplar floodplain forests was evaluated from 1950 to the present time using Kruskal-Wallis non-parametric ANOVA. According to the analysis results, along the time gradient there is a significant increase in the number and cover of neophytes among analysed periods. This result is not caused by increasing biodiversity, because the number of native species significantly decreased. Therefor it is necessary to look for reasons of this situation in deteriorating condition of floodplain biotopes. (authors)

Marvel-ous Dwarfs: Results from Four Heroically Large Simulated Volumes of Dwarf Galaxies

Science.gov (United States)

Munshi, Ferah; Brooks, Alyson; Weisz, Daniel; Bellovary, Jillian; Christensen, Charlotte

2018-01-01

We present results from high resolution, fully cosmological simulations of cosmic sheets that contain many dwarf galaxies. Together, they create the largest collection of simulated dwarf galaxies to date, with z=0 stellar masses comparable to the LMC or smaller. In total, we have simulated almost 100 luminous dwarf galaxies, forming a sample of simulated dwarfs which span a wide range of physical (stellar and halo mass) and evolutionary properties (merger history). We show how they can be calibrated against a wealth of observations of nearby galaxies including star formation histories, HI masses and kinematics, as well as stellar metallicities. We present preliminary results answering the following key questions: What is the slope of the stellar mass function at extremely low masses? Do halos with HI and no stars exist? What is the scatter in the stellar to halo mass relationship as a function of dwarf mass? What drives the scatter? With this large suite, we are beginning to statistically characterize dwarf galaxies and identify the types and numbers of outliers to expect.

From strange stars to strange dwarfs

International Nuclear Information System (INIS)

Glendenning, N.K.; Kettner, C.; Weber, F.

1995-01-01

We determine all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from massive strange stars to strange white dwarf endash like objects (strange dwarfs). The properties of such stars are compared with those of their nonstrange counterparts emdash neutron stars and ordinary white dwarfs. The main emphasis of this paper is on strange dwarfs, which we divide into two distinct categories. The first one consists of a core of strange matter enveloped within ordinary white dwarf matter. Such stars are hydrostatically stable with or without the strange core and are therefore referred to as open-quote open-quote trivial close-quote close-quote strange dwarfs. This is different for the second category which forms an entirely new class of dwarf stars that contain nuclear material up to 4x10 4 times denser than in ordinary white dwarfs of average mass, M∼0.6 M circle-dot , and still about 400 times denser than in the densest white dwarfs. The entire family of such dwarfs, denoted dense strange dwarfs, owes its hydrostatic stability to the strange core. A striking features of strange dwarfs is that the entire sequence from the maximum-mass strange star to the maximum-mass strange dwarf is stable to radial oscillations. The minimum-mass star is only conditionally stable, and the sequences on both sides are stable. Such a stable, continuous connection does not exist between ordinary white dwarfs and neutron stars, which are known to be separated by a broad range of unstable stars. We find an expansive range of very low mass (planetary-like) strange-matter stars (masses even below 10 -4 M circle-dot are possible) that arise as natural dark-matter candidates, which if abundant enough in our Galaxy, should be seen in the gravitational microlensing searches that are presently being performed. copyright 1995 The American Astronomical Society

The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

Science.gov (United States)

Rytter, Rose-Marie

2013-09-01

The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots water availability. Fine root production (treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

Hubble Space Telescope Imaging and Spectral Analysis of Two Brown Dwarf Binaries at the L Dwarf/T Dwarf Transition

OpenAIRE

Burgasser, Adam J.; Gagliuffi, Daniella C. Bardalez; Gizis, John E.

2010-01-01

We present a detailed examination of the brown dwarf multiples 2MASS J08503593+1057156 and 2MASS J17281150+3948593, both suspected of harboring components that straddle the L dwarf/T dwarf transition. Resolved photometry from Hubble Space Telescope/NICMOS show opposite trends in the relative colors of the components, with the secondary of 2MASS J0850+1057 being redder than its primary, while that of 2MASS J1728+3948 is bluer. We determine near-infrared component types by matching combined-lig...

Tratamiento de un efluente textil mediante electrooxidación-Salix babylonica

OpenAIRE

Sánchez Sánchez, Hilda Alejandra

2016-01-01

A nivel mundial, la industria textil es considerada una de las principales fuentes de descarga que afectan la calidad del agua debido al gran volumen que emplea en sus procesos y al uso de una amplia gama de colorantes sintéticos. En esta investigación se evaluó el tratamiento de un agua residual textil mediante un sistema acoplado de electrooxidación-Salix babylonica usando electrodos DDB. En el estudio, se construyó una celda electroquímica en batch, utilizando 5 electrodos paralelos vertic...

Biomass power for rural development: Phase 2. Technical progress report, April 1--June 30, 1998

Energy Technology Data Exchange (ETDEWEB)

Neuhauser, E.

1998-11-01

The project undertaken by the Salix Consortium is a multi-phased, multi-partner endeavor. Phase-1 focused on initial development and testing of the technology and agreements necessary to demonstrate commercial willow production in Phase-2. The Phase-1 objectives have been successfully completed: preparing final design plans for two utility pulverized coal boilers, developing fuel supply plans for the project, obtaining power production commitments from the power companies for Phase-2, obtaining construction and environmental permits, and developing an experimental strategy for crop production and power generation improvements needed to assure commercial success. The R and D effort also addresses environmental issues pertaining to introduction of the willow energy system. Beyond those Phase-1 requirements the Consortium has already successfully demonstrated cofiring at Greenidge Station and developed the required nursery capacity for acreage scale-up. This past summer 105 acres were prepared in advance for the spring planting in 1998. Having completed the above tasks, the Consortium is well positioned to begin Phase-2. In phase-2 every aspect of willow production and power generation from willow will be demonstrated. The ultimate objective of Phase-2 is to transition the work performed under the Rural Energy for the Future project into a thriving, self-supported energy crop enterprise.

Water Quality Changes in a Short-Rotation Woody Crop Riparian Buffer

Science.gov (United States)

Rosa, D.; Clausen, J.; Kuzovkina, J.

2016-12-01

Converting riparian buffers in agricultural areas from annual row crops to short rotation woody crops (SRWCs) grown for biofuel can provide both water quality benefits and a financial incentive for buffer adoption among agricultural producers. A randomized complete block design was used to determine water quality changes resulting from converting plots previously cultivated in corn to SRWC willow (Salix. spp) adjacent to a stream in Storrs, CT. Both overland flow and ground water samples were analyzed for total nitrogen (TN), nitrate + nitrite (NO2+NO3-N), and total phosphorus (TP). Overland flow was also analyzed for suspended solids concentration (SSC). Lower (p = 0.05) concentrations of TN (56%) and TP (61%) were observed in post-coppice surface runoff from willow plots than from corn plots. Shallow ground water concentrations at the edge of willow plots were lower in TN (56%) and NO3+NO2-N (64%), but 35% higher in TP, than at the edge of corn plots. SSC was also lower (72%) in overland flow associated with willow compared to corn. The treatment had no effect on discharge or mass export. These results suggest conversion from corn to a SRWC in a riparian area can provide water quality benefits similar to those observed in restored and established buffers.

Brown dwarfs as dark galactic halos

International Nuclear Information System (INIS)

Adams, F.C.; Walker, T.P.

1990-01-01

The possibility that the dark matter in galactic halos can consist of brown dwarf stars is considered. The radiative signature for such halos consisting solely of brown dwarfs is calculated, and the allowed range of brown dwarf masses, the initial mass function (IMF), the stellar properties, and the density distribution of the galactic halo are discussed. The prediction emission from the halo is compared with existing observations. It is found that, for any IMF of brown dwarfs below the deuterium burning limit, brown dwarf halos are consistent with observations. Brown dwarf halos cannot, however, explain the recently observed near-IR background. It is shown that future satellite missions will either detect brown dwarf halos or place tight constraints on the allowed range of the IMF. 30 refs

Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior

Science.gov (United States)

Darrah, Abigail J.; Greeney, Harold F.; van Riper, Charles

2017-01-01

The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the Colorado River in Mexico. To assess the potential effects of habitat modification resulting from the pulse flow, we used foraging behavior of spring migrants from past and current studies to assess the relative importance of different riparian habitats. We observed foraging birds in 2000 and 2014 at five riparian sites along the Lower Colorado River in Mexico to quantify prey attack rates, prey attack maneuvers, vegetation use patterns, and degree of preference for fully leafed-out or flowering plants. Prey attack rate was highest in mesquite (Prosopis spp.) in 2000 and in willow (Salix gooddingii) in 2014; correspondingly, migrants predominantly used mesquite in 2000 and willow in 2014 and showed a preference for willows in flower or fruit in 2014. Wilson’s warbler (Cardellina pusilla) used relatively more low-energy foraging maneuvers in willow than in tamarisk (Tamarix spp.) or mesquite. Those patterns in foraging behavior suggest native riparian vegetation, and especially willow, are important resources for spring migrants along the lower Colorado River. Willow is a relatively short-lived tree dependent on spring floods for dispersal and establishment and thus spring migrants are likely to benefit from controlled pulse flows.

Climate impact and energy efficiency from electricity generation through anaerobic digestion or direct combustion of short rotation coppice willow

International Nuclear Information System (INIS)

Ericsson, Niclas; Nordberg, Åke; Sundberg, Cecilia; Ahlgren, Serina; Hansson, Per-Anders

2014-01-01

Highlights: • Using LCA, CHP from willow use in biogas was compared with direct combustion. • Direct combustion was ninefold more energy-efficient. • Biogas had a much greater cooling effect on global mean surface temperature. • The effects of soil carbon changes on temperature over time differed. • Biogas had long-term temperature effects, direct combustion short-term effects. - Abstract: Short rotation coppice willow is an energy crop used in Sweden to produce electricity and heat in combined heat and power plants. Recent laboratory-scale experiments have shown that SRC willow can also be used for biogas production in anaerobic digestion processes. Here, life cycle assessment is used to compare the climate impact and energy efficiency of electricity and heat generated by these measures. All energy inputs and greenhouse gas emissions, including soil organic carbon fluxes were included in the life cycle assessment. The climate impact was determined using time-dependent life cycle assessment methodology. Both systems showed a positive net energy balance, but the direct combustion system delivered ninefold more energy than the biogas system. Both systems had a cooling effect on the global mean surface temperature change. The cooling impact per hectare from the biogas system was ninefold higher due to the carbon returned to soil with the digestate. Compensating the lower energy production of the biogas system with external energy sources had a large impact on the result, effectively determining whether the biogas scenario had a net warming or cooling contribution to the global mean temperature change per kWh of electricity. In all cases, the contribution to global warming was lowered by the inclusion of willow in the energy system. The use of time-dependent climate impact methodology shows that extended use of short rotation coppice willow can contribute to counteract global warming

Extracellular enzyme activity in a willow sewage treatment system.

Science.gov (United States)

Brzezinska, Maria Swiontek; Lalke-Porczyk, Elżbieta; Kalwasińska, Agnieszka

2012-12-01

This paper presents the results of studies on the activity of extra-cellular enzymes in soil-willow vegetation filter soil which is used in the post-treatment of household sewage in an onsite wastewater treatment system located in central Poland. Wastewater is discharged from the detached house by gravity into the onsite wastewater treatment system. It flows through a connecting pipe into a single-chamber septic tank and is directed by the connecting pipe to a control well to be further channelled in the soil-willow filter by means of a subsurface leaching system. Soil samples for the studies were collected from two depths of 5 cm and 1 m from three plots: close to the wastewater inflow, at mid-length of the plot and close to its terminal part. Soil samples were collected from May to October 2009. The activity of the extra-cellular enzymes was assayed by the fluorometric method using 4-methylumbelliferyl and 7-amido-4-methylcoumarin substrate. The ranking of potential activity of the assayed enzymes was the same at 5 cm and 1 m soil depths, i.e. esterase > phosphmomoesterase > leucine-aminopeptidase > β-glucosidase > α-glucosidase. The highest values of enzymatic activity were recorded in the surface layer of the soil at the wastewater inflow and decreased with increasing distance from that point.

Testing Gravity Using Dwarf Stars

OpenAIRE

Sakstein, Jeremy

2015-01-01

Generic scalar-tensor theories of gravity predict deviations from Newtonian physics inside astrophysical bodies. In this paper, we point out that low mass stellar objects, red and brown dwarf stars, are excellent probes of these theories. We calculate two important and potentially observable quantities: the radius of brown dwarfs and the minimum mass for hydrogen burning in red dwarfs. The brown dwarf radius can differ significantly from the GR prediction and upcoming surveys that probe the m...

DETERMINATION OF RUTIN IN LEAVES OF SALIX TRIANDRA USING THE METHOD OF PLANAR CHROMATOGRAPHY

Directory of Open Access Journals (Sweden)

E. G. Sannikova

2016-01-01

Full Text Available The aim of the study is to develop new methods of identification and quantitative determination of rutin in the leaves of Salix triandra L. with thin-layer chromatography. The digital processing of the chromatograms was performed using «Sorbfil Videodensitometer» computer program (Krasnodar. For the chromatography analysis we used plates «Sorbfil» PTSH-P-A-UV, mobile phase: n-butanol-glacial acetic acid-water (4:1:1, detecting reagent – ammonia vapors. The rutin is detected as yellow spots with Rf 0.64±0.02. The detection limit is 0.5 μg/μl. The regression equation has the form: S=4.75×103 m. With the use of this method we found that the composition of rutin in leaves of Salix triandra was in the range 1.81±0.06% on the air-dry raw material (relative standard deviation RSD%=2.5%; the measurement error E=3.12%. The method is sensitive, linear, has a small error, and does not require expensive equipment.

The galactic population of white dwarfs

International Nuclear Information System (INIS)

Napiwotzki, Ralf

2009-01-01

The contribution of white dwarfs of the different Galactic populations to the stellar content of our Galaxy is only poorly known. Some authors claim a vast population of halo white dwarfs, which would be in accordance with some investigations of the early phases of Galaxy formation claiming a top-heavy initial- mass- function. Here, I present a model of the population of white dwarfs in the Milky Way based on observations of the local white dwarf sample and a standard model of Galactic structure. This model will be used to estimate the space densities of thin disc, thick disc and halo white dwarfs and their contribution to the baryonic mass budget of the Milky Way. One result of this investigation is that white dwarfs of the halo population contribute a large fraction of the Galactic white dwarf number count, but they are not responsible for the lion's share of stellar mass in the Milky Way. Another important result is the substantial contribution of the - often neglected - population of thick disc white dwarfs. Misclassification of thick disc white dwarfs is responsible for overestimates of the halo population in previous investigations.

Dwarfs in ancient Egypt.

Science.gov (United States)

Kozma, Chahira

2006-02-15

Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. Copyright (c) 2005 Wiley-Liss, Inc.

THE LINK BETWEEN PLANETARY SYSTEMS, DUSTY WHITE DWARFS, AND METAL-POLLUTED WHITE DWARFS

International Nuclear Information System (INIS)

Debes, John H.; Walsh, Kevin J.; Stark, Christopher

2012-01-01

It has long been suspected that metal-polluted white dwarfs (types DAZ, DBZ, and DZ) and white dwarfs with dusty disks possess planetary systems, but a specific physical mechanism by which planetesimals are perturbed close to a white dwarf has not yet been fully posited. In this paper, we demonstrate that mass loss from a central star during post-main-sequence evolution can sweep planetesimals into interior mean motion resonances with a single giant planet. These planetesimals are slowly removed through chaotic excursions of eccentricity that in time create radial orbits capable of tidally disrupting the planetesimal. Numerical N-body simulations of the solar system show that a sufficient number of planetesimals are perturbed to explain white dwarfs with both dust and metal pollution, provided other white dwarfs have more massive relic asteroid belts. Our scenario requires only one Jupiter-sized planet and a sufficient number of asteroids near its 2:1 interior mean motion resonance. Finally, we show that once a planetesimal is perturbed into a tidal crossing orbit, it will become disrupted after the first pass of the white dwarf, where a highly eccentric stream of debris forms the main reservoir for dust-producing collisions. These simulations, in concert with observations of white dwarfs, place interesting limits on the frequency of planetary systems around main-sequence stars, the frequency of planetesimal belts, and the probability that dust may obscure future terrestrial planet finding missions.

Search for brown dwarfs and late M dwarfs in the Hyades and the Pleiades

International Nuclear Information System (INIS)

Zuckerman, B.; Becklin, E.E.; Hawaii Univ., Honolulu)

1987-01-01

The J and K colors of 14 white dwarfs that are believed to be single stars and members of either the Hyades or Pleiades clusters or the Hyades supercluster were measured, and no indication of any excess 2.2 micron (K) emission above that expected from the white dwarf was found. Based on recently published theoretical cooling curves for brown dwarfs, the existence of any cool companion stars, with masses greater than approximately 0.03 solar mass within a radius of 6 arcsec of eight white dwarfs in the Hyades cluster and greater than approximately 0.015 solar mass toward the single white dwarf in the Pleiades, is ruled out. This latter limit, only 15 Jupiter masses, is probably the lowest that has yet been established for any star by purely infrared techniques. 21 references

Vegetationsfilter för rening av lakvatten - kväveaspekter

OpenAIRE

Wennman, Pär

1999-01-01

Short rotation energy forests with willows (Salix spp) have come into increased use in Sweden for treatment of different types of waste water, sludge and ash. The vegetation does not only have a cleaning effect on the water, it is also appaerent that the water, sludge or ash often function as fertiliser for the fast growing crop. Leachate water from municipal landfills in the methanogenic phase can be cleaned with short rotation forests through a so called vegetation filter. In a small scale ...

Host phylogeny and nutrient content drive galler diversity and abundance on willows

Czech Academy of Sciences Publication Activity Database

Volf, Martin; Kadlec, J.; Butterill, Philip T.; Novotný, Vojtěch

2017-01-01

Roč. 42, č. 5 (2017), s. 685-688 ISSN 0307-6946 R&D Projects: GA ČR GB14-36098G Grant - others:GA JU(CZ) 04-152/2016/P Institutional support: RVO:60077344 Keywords : defensive traits * herbivores * Salix Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.771, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/een.12420/abstract

Frost-related dieback of Swedish and Estonian Salix plantations due to pathogenic and ice nucleation-active bacteria

Energy Technology Data Exchange (ETDEWEB)

Cambours, M.A.

2004-07-01

During the past decade, important dieback has been observed in short-rotation forestry plantations of Salix viminalis and S. dasyclados in Sweden and Estonia, plantations from which the isolation of ice nucleation-active (INA) and pathogenic bacteria has also been reported. This thesis investigates the connection between bacterial infection and frost as a possible cause for such damage, and the role played by internal and external factors (e.g. plant frost sensitivity, fertilisation) in the dieback observed. Bacterial floras isolated from ten Salix clones growing on fertilised/unfertilised mineral soil or nitrogen-rich organic soil, were studied. Culturable bacterial communities present both in internal necrotic tissues and on the plant surface (i.e. epiphytes) were isolated on two occasions (spring and autumn). The strains were biochemically characterised (with gram, oxidase and fluorescence tests), and tested for ice nucleation-activity. Their pathogenic properties were studied with and without association to a freezing stress. Certain strains were eventually identified with BIOLOG plates and 16S rRNA analysis. A high number of culturable bacterial strains was found in the plant samplings, belonging mainly to Erwinia and Sphingomonas spp.; pathogenic and INA communities being mostly Erwinia-, Sphingomonas- and Xanthomonas-like. The generally higher plant dieback noted in the field on nutrient-rich soils and for frost sensitive clones was found connected to higher numbers of pathogenic and INA bacteria in the plants. We thus confirm Salix dieback to be related to a synergistic effect of frost and bacterial infection, possibly aggravated by fertilisation.

Cryopreservation of Populus trichocarpa and Salix using dormant buds with recovery by grafting or direct rooting

Science.gov (United States)

Populus trichocarpa and Salix can be successfully cryopreserved by using dormant scions as the source explants. These scions (either at their original moisture content of 48 to 60% or dried to 30%) were slowly cooled to –35 degree Celsius, transferred to the vapor phase of liquid nitrogen (LNV,-160...

Binary Star Orbits. V. The Nearby White Dwarf/Red Dwarf Pair 40 Eri BC

Science.gov (United States)

Mason, Brian D.; Hartkopf, William I.; Miles, Korie N.

2017-11-01

A new relative orbit solution with new dynamical masses is determined for the nearby white dwarf-red dwarf pair 40 Eri BC. The period is 230.09 ± 0.68 years. It is predicted to close slowly over the next half-century, getting as close as 1.″32 in early 2066. We determine masses of 0.575 ± 0.018 {{ M }}⊙ for the white dwarf and 0.2041 ± 0.0064 {{ M }}⊙ for the red dwarf companion. The inconsistency of the masses determined by gravitational redshift and dynamical techniques, due to a premature orbit calculation, no longer exists.

The ultracool-field dwarf luminosity-function and space density from the Canada-France Brown Dwarf Survey

Science.gov (United States)

Reylé, C.; Delorme, P.; Willott, C. J.; Albert, L.; Delfosse, X.; Forveille, T.; Artigau, E.; Malo, L.; Hill, G. J.; Doyon, R.

2010-11-01

Context. Thanks to recent and ongoing large scale surveys, hundreds of brown dwarfs have been discovered in the last decade. The Canada-France Brown Dwarf Survey is a wide-field survey for cool brown dwarfs conducted with the MegaCam camera on the Canada-France-Hawaii Telescope. Aims: Our objectives are to find ultracool brown dwarfs and to constrain the field brown-dwarf luminosity function and the mass function from a large and homogeneous sample of L and T dwarfs. Methods: We identify candidates in CFHT/MegaCam i' and z' images and follow them up with pointed near infrared (NIR) imaging on several telescopes. Halfway through our survey we found ~50 T dwarfs and ~170 L or ultra cool M dwarfs drawn from a larger sample of 1400 candidates with typical ultracool dwarfs i'-z' colours, found in 780 square degrees. Results: We have currently completed the NIR follow-up on a large part of the survey for all candidates from mid-L dwarfs down to the latest T dwarfs known with utracool dwarfs' colours. This allows us to draw on a complete and well defined sample of 102 ultracool dwarfs to investigate the luminosity function and space density of field dwarfs. Conclusions: We found the density of late L5 to T0 dwarfs to be 2.0+0.8-0.7 × 10-3 objects pc-3, the density of T0.5 to T5.5 dwarfs to be 1.4+0.3-0.2 × 10-3 objects pc-3, and the density of T6 to T8 dwarfs to be 5.3+3.1-2.2 × 10-3 objects pc-3. We found that these results agree better with a flat substellar mass function. Three latest dwarfs at the boundary between T and Y dwarfs give the high density 8.3+9.0-5.1 × 10-3 objects pc-3. Although the uncertainties are very large this suggests that many brown dwarfs should be found in this late spectral type range, as expected from the cooling of brown dwarfs, whatever their mass, down to very low temperature. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by

Development of short-rotation willow coppice systems for environmental purposes in Sweden

International Nuclear Information System (INIS)

Mirck, Jaconette; Verwijst, Theo; Isebrands, J.G.; Ledin, Stig

2005-01-01

During the last three decades, driving forces behind the development of short-rotation willow coppice (SRWC) in Sweden have been changing from a primary focus on biomass production towards emphasis on environmental applications. In most cases, current commercial SRWC practice is geared towards a combination of biomass production for energy purposes and environmental goals. The latter goals range from decreasing the impact of specific contaminants in the environment to organic waste handling in a recycling system in urban and/or agricultural areas. Where biomass production and pollutant management overlap, the science of phytoremediation has its practical application. Through phytoremediation, waste products that previously have been a burden for society can be used as valuable resources to increase short-rotation willow biomass production. In this paper we will present the terminology and definitions of different types of phytoremediation. We also give an overview of five different cases of phytoremediation activities with a potential for large-scale implementation. Some of the types of activities are already commercially used in Sweden; others seem promising but still need further development. (Author)

High doses of ethylenediurea (EDU) as soil drenches did not increase leaf N content or cause phytotoxicity in willow grown in fertile soil.

Science.gov (United States)

Agathokleous, Evgenios; Paoletti, Elena; Manning, William J; Kitao, Mitsutoshi; Saitanis, Costas J; Koike, Takayoshi

2018-01-01

Ground-level ozone (O 3 ) levels are nowadays elevated in wide regions of the Earth, causing significant effects on plants that finally lead to suppressed productivity and yield losses. Ethylenediurea (EDU) is a chemical compound which is widely used in research projects as phytoprotectant against O 3 injury. The EDU mode of action remains still unclear, while there are indications that EDU may contribute to plants with nitrogen (N) when the soil is poor in N and the plants have relatively small leaf area. To reveal whether the N content of EDU acts as a fertilizer to plants when the soil is not poor in N and the plants have relatively large total plant leaf area, willow plants (Salix sachalinensis Fr. Schm) were exposed to low ambient O 3 levels and treated ten times (9-day interval) with 200mL soil drench containing 0, 800 or 1600mg EDU L -1 . Fertilizer was added to a nutrient-poor soil, and the plants had an average plant leaf area of 9.1m 2 at the beginning of EDU treatments. Indications for EDU-induced hormesis in maximum electron transport rate (J max ) and ratio of intercellular to ambient CO 2 concentration (C i :C a ) were observed at the end of the experiment. No other EDU-induced effects on leaf greenness and N content, maximum quantum yield of photosystem II (F v /F m ), gas exchange, growth and matter production suggest that EDU did not act as N fertilizer and did not cause toxicity under these experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Southwestern willow flycatchers (Empidonax traillii extimus) in a grazed landscape: factors influencing brood parasitism

Science.gov (United States)

Katherine M. Brodhead; Scott H. Stoleson; Deborah M. Finch

2007-01-01

Brood parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter "cowbirds") is an important factor contributing to the endangered status of the Southwestern Willow Flycatcher (Empidonax traillii extimus, hereafter "flycatcher"). We report on factors that influence brood parasitism on the flycatcher using...

The brown dwarf kinematics project

Science.gov (United States)

Faherty, Jackie K.

2010-10-01

Brown dwarfs are a recent addition to the plethora of objects studied in Astronomy. With theoretical masses between 13 and 75 MJupiter , they lack sustained stable Hydrogen burning so they never join the stellar main sequence. They have physical properties similar to both planets and low-mass stars so studies of their population inform on both. The distances and kinematics of brown dwarfs provide key statistical constraints on their ages, moving group membership, absolute brightnesses, evolutionary trends, and multiplicity. Yet, until my thesis, fundamental measurements of parallax and proper motion were made for only a relatively small fraction of the known population. To address this deficiency, I initiated the Brown Dwarf Kinematics (BDKP). Over the past four years I have re-imaged the majority of spectroscopically confirmed field brown dwarfs (or ultracool dwarfs---UCDs) and created the largest proper motion catalog for ultracool dwarfs to date. Using new astrometric information I examined population characteristics such as ages calculated from velocity dispersions and correlations between kinematics and colors. Using proper motions, I identified several new wide co-moving companions and investigated binding energy (and hence formation) limitations as well as the frequency of hierarchical companions. Concurrently over the past four years I have been conducting a parallax survey of 84 UCDs including those showing spectral signatures of youth, metal-poor brown dwarfs, and those within 20 pc of the Sun. Using absolute magnitude relations in J,H, and K, I identified overluminous binary candidates and investigated known flux-reversal binaries. Using current evolutionary models, I compared the MK vs J-K color magnitude diagram to model predictions and found that the low-surface gravity dwarfs are significantly red-ward and underluminous of predictions and a handful of late-type T dwarfs may require thicker clouds to account for their scatter.

White dwarfs - the once and future suns

International Nuclear Information System (INIS)

Trimble, V.

1986-01-01

The history and properties of white dwarfs (Bessel's conclusion that Sirius and Procyon have invisible companions, Clark's discovery of Sirius B, Adams and Russell's study of white dwarf spectra, Chandrasekhar's explanation of white dwarf structure by equations incorporating quantum mechanics and relativity) are treated. Formation of white dwarfs, degeneracy, binary white dwarfs (and novae and supernovae) are explained. A mystery nearly 50 years old regarding the spectrum of the star Greenwich +70 degrees-8247 has been solved: it involves a stationary line phenomenon and a magnetic field of 300-500 million gauss. Processes being studied in white dwarfs and white dwarf models include gravitational settling, accretion, dredge-up, radiation pressure, and diffusive hydrogen burning

WHITE DWARF-RED DWARF SYSTEMS RESOLVED WITH THE HUBBLE SPACE TELESCOPE. II. FULL SNAPSHOT SURVEY RESULTS

International Nuclear Information System (INIS)

Farihi, J.; Hoard, D. W.; Wachter, S.

2010-01-01

Results are presented for a Hubble Space Telescope Advanced Camera for Surveys high-resolution imaging campaign of 90 white dwarfs with known or suspected low-mass stellar and substellar companions. Of the 72 targets that remain candidate and confirmed white dwarfs with near-infrared excess, 43 are spatially resolved into two or more components, and a total of 12 systems are potentially triples. For 68 systems where a comparison is possible, 50% have significant photometric distance mismatches between their white dwarf and M dwarf components, suggesting that white dwarf parameters derived spectroscopically are often biased due to the cool companion. Interestingly, 9 of the 30 binaries known to have emission lines are found to be visual pairs and hence widely separated, indicating an intrinsically active cool star and not irradiation from the white dwarf. There is a possible, slight deficit of earlier spectral types (bluer colors) among the spatially unresolved companions, exactly the opposite of expectations if significant mass is transferred to the companion during the common envelope phase. Using the best available distance estimates, the low-mass companions to white dwarfs exhibit a bimodal distribution in projected separation. This result supports the hypothesis that during the giant phases of the white dwarf progenitor, any unevolved companions either migrate inward to short periods of hours to days, or outward to periods of hundreds to thousands of years. No intermediate projected separations of a few to several AU are found among these pairs. However, a few double M dwarfs (within triples) are spatially resolved in this range, empirically demonstrating that such separations were readily detectable among the binaries with white dwarfs. A straightforward and testable prediction emerges: all spatially unresolved, low-mass stellar and substellar companions to white dwarfs should be in short-period orbits. This result has implications for substellar companion and

Heavy metal accumulation in trees growing on contaminated sites in Central Europe

International Nuclear Information System (INIS)

Unterbrunner, R.; Puschenreiter, M.; Sommer, P.; Wieshammer, G.; Tlustos, P.; Zupan, M.; Wenzel, W.W.

2007-01-01

Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg -1 and 4680 mg Zn kg -1 in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH 4 NO 3 extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg -1 and 116 mg Cd kg -1 in their leaves

Heavy metal accumulation in trees growing on contaminated sites in Central Europe

Energy Technology Data Exchange (ETDEWEB)

Unterbrunner, R. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Puschenreiter, M. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)]. E-mail: markus.puschenreiter@boku.ac.at; Sommer, P. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Wieshammer, G. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Tlustos, P. [Czech University of Agriculture Prague, 165 21 Praha 6-Suchdol (Czech Republic); Zupan, M. [University of Ljubljana, Biotechnical Faculty, Agronomy department, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Wenzel, W.W. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)

2007-07-15

Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg{sup -1} and 4680 mg Zn kg{sup -1} in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH{sub 4}NO{sub 3} extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg{sup -1} and 116 mg Cd kg{sup -1} in their leaves.

Distribution and trends of mercury in deciduous tree cores

International Nuclear Information System (INIS)

Siwik, Eden I.H.; Campbell, Linda M.; Mierle, Gregory

2010-01-01

The distribution of total mercury (THg) within common deciduous trees and the applicability of tree cores as biomonitors of historical environmental THg trends were assessed for both contaminated and reference sites around Kingston, Ontario. Samples were collected from Acer spp., Quercus spp. Populus spp. and Salix spp. Bark and wood THg concentrations were found to be highly correlated whereas soil and wood THg concentrations were not. There were no temporal relationships for THg in dated tree rings corresponding with any other known environmental Hg trends. The shoreline speciess, Populus and Salix spp., had the greatest bark and wood Hg concentrations reaching 18 ng/g, significantly higher than for inland trees Quercus and Acer spp. with maximum values of 7 and 1.2 ng/g for bark and wood respectively. While tree cores cannot be reliably used as temporal THg biomonitors, there is promise for tree species such as Populus spp and Salix spp as spatial indicators of local long-term Hg contamination. - Total mercury trends in several deciduous trees did not follow expected environmental trends. Shoreline species (willow and popular) had higher wood THg than inland species (oak and maple).

Formation of dwarf ellipticals and dwarf irregular galaxies by interaction of giant galaxies under environmental influence

OpenAIRE

Chattopadhyay, Tanuka; Debsarma, Suma; Karmakar, Pradip; Davoust, Emmanuel

2014-01-01

A model is proposed for the formation of gas-rich dwarf irregular galaxies and gas-poor, rotating dwarf elliptical galaxies following the interaction between two giant galaxies as a function of space density. The formation of dwarf galaxies is considered to depend on a random variable, the tidal index theta, an environmental parameter defined by Karachentsev et al. (2004), such that for theta less than zero, the formation of dwarf irregular galaxy is assured whereas for theta greater than zer...

Asteroseismology of White Dwarf Stars

Science.gov (United States)

Hansen, Carl J.

1997-01-01

The primary purpose of this investigation has been to study various aspects of multimode pulsations in variable white dwarfs. In particular, nonlinear interactions among pulsation modes in white dwarfs (and, to some extent, in other variable stars), analysis of recent observations where such interactions are important, and preliminary work on the effects of crystallization in cool white dwarfs are reported.

Comparative of Quercus spp. and Salix spp. for phytoremediation of Pb/Zn mine tailings.

Science.gov (United States)

Shi, Xiang; Wang, Shufeng; Sun, Haijing; Chen, Yitai; Wang, Dongxue; Pan, Hongwei; Zou, Yazhu; Liu, Jianfeng; Zheng, Linyu; Zhao, Xiulian; Jiang, Zeping

2017-02-01

A pot experiment was conducted to evaluate the feasibility of using tree seedlings for the phytoremediation of lead/zinc (Pb/Zn) mine tailings. Seedlings of three Quercus spp. (Q. shumardii, Q. phellos, and Q. virginiana) and rooted cuttings of two Salix spp. (S. matsudana and S. integra) were transplanted into pots containing 50 and 100 % Pb/Zn mine tailings to evaluate their tolerance of heavy metals. The five species showed different tolerance levels to the Pb/Zn tailings treatments. Q. virginiana was highly tolerant to heavy metals and grew normally in the Pb/Zn tailings. The root systems showed marked differences between the Quercus spp. and Salix spp., indicating that different mechanisms operated to confer tolerance of heavy metals. The maximum efficiency of photosystem II photochemistry value of the five species showed no differences among the treatments, except for Q. shumardii. All species showed low metal translocation factors (TFs). However, S. integra had significantly higher TF values for Zn (1.42-2.18) and cadmium (1.03-1.45) than did the other species. In this respect, Q. virginiana showed the highest tolerance and a low TF, implying that it is a candidate for phytostabilization of mine tailings in southern China. S. integra may be useful for phytoextraction of tailings in temperate regions.

SDSS DR7 WHITE DWARF CATALOG

Energy Technology Data Exchange (ETDEWEB)

Kleinman, S. J.; Nitta, A. [Gemini Observatory, 670 North A' ohoku Place, Hilo, HI 96720 (United States); Kepler, S. O.; Pelisoli, Ingrid; Pecanha, Viviane; Costa, J. E. S. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Koester, D. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Kiel, D-24098 Kiel (Germany); Krzesinski, J. [Mt. Suhora Observatory, Pedagogical University of Cracow, ul. Podchorazych 2, 30-084 Cracow (Poland); Dufour, P.; Lachapelle, F.-R.; Bergeron, P. [Departement de Physique, Universite de Montreal, C. P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Yip, Ching-Wa [Department of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218 (United States); Harris, Hugh C. [United States Naval Observatory, Flagstaff Station, 10391 West Naval Observatory Road, Flagstaff, AZ 86001-8521 (United States); Eisenstein, Daniel J. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, MS 20, Cambridge, MA 02138 (United States); Althaus, L.; Corsico, A., E-mail: hch@nofs.navy.mil [Facultad de Ciencias Astronomicas y Geofisicas, Paseo del Bosque S/N, (1900) La Plata (Argentina)

2013-01-15

We present a new catalog of spectroscopically confirmed white dwarf stars from the Sloan Digital Sky Survey (SDSS) Data Release 7 spectroscopic catalog. We find 20,407 white dwarf spectra, representing 19,712 stars, and provide atmospheric model fits to 14,120 DA and 1011 DB white dwarf spectra from 12,843 and 923 stars, respectively. These numbers represent more than a factor of two increase in the total number of white dwarf stars from the previous SDSS white dwarf catalogs based on DR4 data. Our distribution of subtypes varies from previous catalogs due to our more conservative, manual classifications of each star in our catalog, supplementing our automatic fits. In particular, we find a large number of magnetic white dwarf stars whose small Zeeman splittings mimic increased Stark broadening that would otherwise result in an overestimated log g if fit as a non-magnetic white dwarf. We calculate mean DA and DB masses for our clean, non-magnetic sample and find the DB mean mass is statistically larger than that for the DAs.

The late-M dwarfs

International Nuclear Information System (INIS)

Bessell, M.S.

1991-01-01

Far-red spectra and VRIJHK photometry have been obtained for a sample of late-M dwarfs selected on the basis of large reduced red magnitudes from the LHS Catalog. Half of the stars in the three faintest 1 mag bins are late-M stars, the other red stars are metallic-hydride subdwarfs. Relations between various colors for the late-M dwarfs are investigated. Of all the colors I - K most reliably correlates with spectral type. FeH bands near 9900 A are clearly seen in the spectra of all dwarf stars later than M5. Two stars cooler than VB10, and similar in temperature to LHS2924 have been identified; both have H-alpha in emission and appear variable in magnitude and R - I color; one is a flare star. The other stars are of earlier spectral type and resemble W359 and VB8. The observed MI, I - K main sequence is in good agreement with the IG theoretical main sequence of Stringfellow, and the faintest stars could be about 0.09 solar mass red dwarfs or lower mass brown dwarfs. 65 refs

Understanding Brown Dwarf Variability

Science.gov (United States)

Marley, Mark S.

2013-01-01

Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

Evolution models of helium white dwarf-main-sequence star merger remnants: the mass distribution of single low-mass white dwarfs

Science.gov (United States)

Zhang, Xianfei; Hall, Philip D.; Jeffery, C. Simon; Bi, Shaolan

2018-02-01

It is not known how single white dwarfs with masses less than 0.5Msolar -- low-mass white dwarfs -- are formed. One way in which such a white dwarf might be formed is after the merger of a helium-core white dwarf with a main-sequence star that produces a red giant branch star and fails to ignite helium. We use a stellar-evolution code to compute models of the remnants of these mergers and find a relation between the pre-merger masses and the final white dwarf mass. Combining our results with a model population, we predict that the mass distribution of single low-mass white dwarfs formed through this channel spans the range 0.37 to 0.5Msolar and peaks between 0.45 and 0.46Msolar. Helium white dwarf--main-sequence star mergers can also lead to the formation of single helium white dwarfs with masses up to 0.51Msolar. In our model the Galactic formation rate of single low-mass white dwarfs through this channel is about 8.7X10^-3yr^-1. Comparing our models with observations, we find that the majority of single low-mass white dwarfs (<0.5Msolar) are formed from helium white dwarf--main-sequence star mergers, at a rate which is about $2$ per cent of the total white dwarf formation rate.

EROS 2 proper motion survey a field brown dwarf and an L dwarf companion to LHS 102

CERN Document Server

Goldman, B; Forveille, T; Afonso, C; Alard, C; Albert, J N; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Bauer, F; Beaulieu, J P; Borsenberger, J; Bouquet, A; Char, S; Charlot, X; Couchot, F; Coutures, C; Derue, F; Ferlet, R; Fouqué, P; Glicenstein, J F; Gould, A; Graff, D S; Gros, M H; Haïssinski, J; Hamilton, J C; Hardin, D P; De Kat, J; Kim, A; Lasserre, T; Lesquoy, E; Loup, C; Magneville, C; Mansoux, B; Marquette, J B; Martín, E L; Maurice, E; Milshtein, A I; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Prévôt, L; Regnault, N; Rich, J; Spiro, Michel; Vidal-Madjar, A; Virgoux, L; Zylberajch, S

1999-01-01

We report the discovery of two L dwarfs (the new spectral class defined for dwarfs cooler than the M type) in a two-epoch CCD proper motion survey of 413 square degrees, complemented by infrared photometry from DENIS. One of them has a strong lithium line and is therefore a brown dwarf. The other is a common proper motion companion to the mid-M dwarf LHS 102 (GJ 1001), which has a well determined trigonometric parallax. LHS 102B is thus the coolest L dwarf of known distance and luminosity. Its infrared absolute photometry are very well reproduced by the Allard et al DUSTY models.

Phytotoxicity of fresh and weathered diesel and gasoline to willow and poplar trees

DEFF Research Database (Denmark)

Trapp, Stefan; Köhler, A.; Larsen, L.C.

2001-01-01

The toxicity of fresh and weathered gasoline and diesel fuel to willow and poplar trees was studied using a tree transpiration toxicity test. Soils were taken from an abandoned filling station. Concentrations in the samples were measured as the sum of hydrocarbons from C5 to C10 (gasoline) and C1...

Seasonal variation in radiocaesium concentration in willow ptarmigan and rock ptarmigan in central Norway after the Chernobyl fallout

International Nuclear Information System (INIS)

Pedersen, H.C.; Nyboe, S.; Varskog, P.

1998-01-01

Radioactive caesium (20-60 kBq m -2 ) was deposited after the Chernobyl accident in the mountains of central Norway. Two sympatric ptarmigan species, willow ptarmigan Lagopus lagopus and rock ptarmigan L. mutus, inhabit this alpine ecosystem and are important game species. In 1987 and 1988, a study was carried out to try to identify factors affecting radioactive caesium concentration in these birds. Juvenile willow ptarmigan contained more radiocaesium than adults, but the two sexes did not differ in radiocaesium concentration. The radiocaesium concentration of food plants correlated with radiocaesium concentration of rock ptarmigan, and a seasonal variation in radiocaesium concentration of both ptarmigan species was seen. Rock ptarmigan contained more radiocaesium than willow ptarmigan during winter, but not in summer. This difference was related to differences in diet. The bioconcentration factor was 0·4-0·6. The aggregated transfer coefficient was 0·003-0·009 m 2 kg -1 for both species. In spite of the high deposition, the radiocaesium concentration in muscle rarely exceeded the limit recommended for human food consumption (600 Bq kg -1 ). (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Past and future range shifts and loss of diversity in dwarf willow (Salix herbaceae L.) inferred from genetics, fossils and modelling

DEFF Research Database (Denmark)

Alsos, Inger Greve; Alm, Torbjørn; Normand, Signe

2009-01-01

. Macrofossil records were compiled to infer past distribution, and species distribution models were used to predict the Last Glacial Maximum (LGM) and future distribution of climatically suitable areas. Results  We found strong genetic differentiation between the populations from Europe/East Greenland...... during the last glaciation was inferred based on the fossil records and distribution modelling. A 46-57% reduction in suitable areas was predicted in 2080 compared to present. However, mainly southern alpine populations may go extinct, causing a loss of about 5% of the genetic diversity in the species....... Main conclusions  From a continuous range in Central Europe during the last glaciation, northward colonization probably occurred as a broad front maintaining diversity as the climate warmed. This explains why potential extinction of southern populations by 2080 will cause a comparatively low loss...

Infrared photometry of cool white dwarfs

International Nuclear Information System (INIS)

Wickramasinghe, D.T.; Allen, D.A.; Bessell, M.S.

1982-01-01

The results are presented of a search for the effects of pressure induced H 2 dipole opacity on the infrared JHK magnitudes of cool white dwarfs. LHS 1126 is found to be a very cool (Tsub(e) approximately 4250 K) DC white dwarf with a H rich atmospheric composition dominated by H 2 dipole opacity in the infrared. JHK photometry also favours a H rich atmospheric composition for the DK white dwarfs LP 658-2 and W 489. The surprisingly high proportion of hydrogen rich white dwarfs in the sample appears to suggest that the mechanism which inhibits the accretion of hydrogen in the hotter helium stars becomes less effective at low (Tsub(e) approximately 3 + ion in cool hydrogen rich white dwarf atmospheres is pointed out and it is suggested that the opacity due to this ion may be responsible for the blanketing observed in the U and B magnitudes of some cool white dwarfs. (author)

The Hunt for Missing Dwarf Galaxies

Science.gov (United States)

Kohler, Susanna

2015-11-01

Theories of galaxy formation and evolution predict that there should be significantly more dwarf galaxies than have been observed. Are our theories wrong? Or are dwarf galaxies just difficult to detect? Recent results from a survey of a galaxy cluster 62 million light-years away suggest there may be lots of undiscovered dwarf galaxies hiding throughout the universe!Hiding in FaintnessThe missing dwarf problem has had hints of a resolution with the recent discovery of Ultra-Diffuse Galaxies (UDGs) in the Coma and Virgo galaxy clusters. UDGs have low masses and large radii, resulting in a very low surface brightness that makes them extremely difficult to detect. If many dwarfs are UDGs, this could well explain why weve been missing them!But the Coma and Virgo galaxy clusters are similar in that theyre both very massive. Are there UDGs in other galaxy clusters as well? To answer this question, an international team of scientists is running the Next Generation Fornax Survey (NGFS), a survey searching for faint dwarf galaxies in the central 30 square degrees of the Fornax galaxy cluster.The NGFS uses near-UV and optical observations from the Dark Energy Camera mounted on the 4m Blanco Telescope in Chile. The survey is still underway, but in a recent publication led by Roberto P. Muoz (Institute of Astrophysics at the Pontifical Catholic University of Chile), the team has released an overview of the first results from only the central 3 square degrees of the NGFS field.Surprising DetectionGalaxy radii vs. their absolute i-band magnitudes, for the dwarfs found in NGFS as well as other stellar systems in the nearby universe. The NGFS dwarfs are similar to the ultra-diffuse dwarfs found in the Virgo and Coma clusters, but are several orders of magnitude fainter. [Muoz et al. 2015]In just this small central field, the team has found an astounding 284 low-surface-brightness dwarf galaxy candidates 158 of them previously undetected. At the bright end of this sample are dwarf

Lists of semi-dwarf cereal stocks

International Nuclear Information System (INIS)

1984-01-01

The lists are prepared in relation to the Co-ordinated Research Programme. At the first Research Co-ordination Meeting on evaluation of cereal semi-dwarf mutants for cross breeding, March 1981, programme participants were requested to list semi-dwarf mutants available at their institutes including also non-induced semi-dwarf stocks being used in cross-breeding programme for short stature. List-I is prepared from such lists provided by programme participants. Further it was requested to name breeders and institutes providing characteristics of the listed semi-dwarf stocks. List-II gives that information. In the List-I: Parents of semi-dwarf stocks derived from cross breeding, are shown in brackets. In column ''Culm length'', figures are in cm and those of parent cultivars are shown in brackets

Pulsations in white dwarf stars

OpenAIRE

Van Grootel, Valérie; Fontaine, Gilles; Brassard, Pierre; Dupret, Marc-Antoine

2017-01-01

I will present a description of the six distinct families of pulsating white dwarfs that are currently known. Pulsations are present at various stages of the evolution (from hot, pre-white dwarfs to cool white dwarfs), at various stellar masses, and for various atmospheric compositions. In all of them, a mechanism linked to opacity changes along the evolution drives the oscillations. The existence of these oscillations offers the opportunity to apply asteroseismology for constraining physics ...

White dwarfs in the WTS: Eclipsing binaries

Directory of Open Access Journals (Sweden)

Burleigh M.R.

2013-04-01

Full Text Available We have identified photometric white dwarf candidates in the WFCAM transit survey through a reduced proper motion versus colour approach. Box-fitting with parameters adjusted to detect the unique signature of a white dwarf + planet/brown dwarf transit/eclipse event was performed, as well as looking for variability due to the irradiation of the companions atmosphere by the white dwarf's high UV flux. We have also performed a simple sensitivity analysis in order to assess the ability of the survey to detect companions to white dwarfs via the transit method.

Habitability of planets around red dwarf stars.

Science.gov (United States)

Heath, M J; Doyle, L R; Joshi, M M; Haberle, R M

1999-08-01

Recent models indicate that relatively moderate climates could exist on Earth-sized planets in synchronous rotation around red dwarf stars. Investigation of the global water cycle, availability of photosynthetically active radiation in red dwarf sunlight, and the biological implications of stellar flares, which can be frequent for red dwarfs, suggests that higher plant habitability of red dwarf planets may be possible.

A systematic search for brown dwarfs orbiting nearby stars

International Nuclear Information System (INIS)

Henry, T.J.; Mccarthy, D.W. Jr.

1990-01-01

Survey data for brown dwarf and stellar companions relative to known M dwarf stars within 5 pc north of -30 deg are analyzed. A region 0.2 to 5 arcsec in radius around 27 stars at the IR H and K bands are examined using IR speckle interferometry. The frequency of binary versus single M dwarfs in the solar neighborhood is examined. The IR mass-magnitude relations and mass-luminosity-age relation are studied. The data reveal that there are 19 single M dwarfs, 8 M dwarf binaries, 1 M dwarf triple system, and 1 M dwarf in a triple system for M dwarfs within 5 pc north of -30 deg. Also of the 27 M dwarfs studied none was found to have a brown dwarf companion. 64 refs

Biomass direct-fired power generation system in China: An integrated energy, GHG emissions, and economic evaluation for Salix

International Nuclear Information System (INIS)

Wang, Changbo; Zhang, Lixiao; Chang, Yuan; Pang, Mingyue

2015-01-01

To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO 2 -eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

Biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli AB1157 cultures submitted to the action of stannous chloride

Directory of Open Access Journals (Sweden)

RAPHAEL S S SOUZA

2009-01-01

Full Text Available Stannous chloride (SnC12 is used in nuclear medicine as a reducing agent to obtain technetium-99m-radiopharmaceuticals. It have been reported that natural products might reduce the genotoxic and cytotoxic effects related to SnC12. This work evaluated the biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli (E. coli AB1157 (wild type cultures submitted to the action of SnC12. E. coli AB1157 cultures (exponential growth phase were collected by centrifugation, washed and resuspended in 0.9%NaCl. Samples were incubated in water bath shaker with: (a SnC12 (25mg/ml, (bSalix alba extract(11.6mg/ml and (cSnC12(25mg/ml + Salix alba extract (11.6mg/ml. Incubation with 0.9% NaCl was also carried out (control. At 60 min intervals, aliquots were withdrawn, diluted, spread onto Petri dishes with solid LB medium and incubated overnight. The colonies formed were counted and the survival fractions calculated. The extract was not able to protect the E. coli cultures against the lesive action of SnC12. The extract also did not interfere with the survival of the cultures. It suggested that the substances present in the Salix alba aqueous extract did not interfere strongly with cellular metabolism and did not alter the survival fractions of E. coli AB 1157. It is speculated that this extract cannot interfere with the generation of free radicals, the possible main agent responsible for SnC12 lesive action.

The Metallicity of Void Dwarf Galaxies

Science.gov (United States)

Kreckel, K.; Croxall, K.; Groves, B.; van de Weygaert, R.; Pogge, R. W.

2015-01-01

The current ΛCDM cosmological model predicts that galaxy evolution proceeds more slowly in lower density environments, suggesting that voids are a prime location to search for relatively pristine galaxies that are representative of the building blocks of early massive galaxies. To test the assumption that void galaxies are more pristine, we compare the evolutionary properties of a sample of dwarf galaxies selected specifically to lie in voids with a sample of similar isolated dwarf galaxies in average density environments. We measure gas-phase oxygen abundances and gas fractions for eight dwarf galaxies (Mr > -16.2), carefully selected to reside within the lowest density environments of seven voids, and apply the same calibrations to existing samples of isolated dwarf galaxies. We find no significant difference between these void dwarf galaxies and the isolated dwarf galaxies, suggesting that dwarf galaxy chemical evolution proceeds independent of the large-scale environment. While this sample is too small to draw strong conclusions, it suggests that external gas accretion is playing a limited role in the chemical evolution of these systems, and that this evolution is instead dominated mainly by the internal secular processes that are linking the simultaneous growth and enrichment of these galaxies.

Evolution of White Dwarf Stars

OpenAIRE

L. G. Althaus

2001-01-01

This paper is aimed at presenting the main results we have obtained for the study of the evoution of white dwarf stars. The calculations are carried out by means of a detailed evolutionary code based on an updated physical description. In particular, we briefly discuss the results for the evolution of white dwarfs of different stellar masses and chemical composition, and the evolution of whit e dwarfs in the framework of a varying gravitational constant G scenario as well.

Calibrating Detailed Chemical Analysis of M dwarfs

Science.gov (United States)

Veyette, Mark; Muirhead, Philip Steven; Mann, Andrew; Brewer, John; Allard, France; Homeier, Derek

2018-01-01

The ability to perform detailed chemical analysis of Sun-like F-, G-, and K-type stars is a powerful tool with many applications including studying the chemical evolution of the Galaxy, assessing membership in stellar kinematic groups, and constraining planet formation theories. Unfortunately, complications in modeling cooler stellar atmospheres has hindered similar analysis of M-dwarf stars. Large surveys of FGK abundances play an important role in developing methods to measure the compositions of M dwarfs by providing benchmark FGK stars that have widely-separated M dwarf companions. These systems allow us to empirically calibrate metallicity-sensitive features in M dwarf spectra. However, current methods to measure metallicity in M dwarfs from moderate-resolution spectra are limited to measuring overall metallicity and largely rely on astrophysical abundance correlations in stellar populations. In this talk, I will discuss how large, homogeneous catalogs of precise FGK abundances are crucial to advancing chemical analysis of M dwarfs beyond overall metallicity to direct measurements of individual elemental abundances. I will present a new method to analyze high-resolution, NIR spectra of M dwarfs that employs an empirical calibration of synthetic M dwarf spectra to infer effective temperature, Fe abundance, and Ti abundance. This work is a step toward detailed chemical analysis of M dwarfs at a similar precision achieved for FGK stars.

Observations of Superwinds in Dwarf Galaxies

Science.gov (United States)

Marlowe, A. T.; Heckman, T. M.; Wyse, R.; Schommer, R.

1993-12-01

Dwarf galaxies are important in developing our understanding of the formation and evolution of galaxies, and of the structure in the universe. The concept of supernova-driven mass outflows is a vital ingredient in theories of the structure and evolution of dwarfs galaxies. We have begun a detailed multi-waveband search for outflows in starbursting dwarf galaxies, and have obtained Fabry-Perot images and Echelle spectra of 20 nearby actively-star-forming dwarf galaxies. In about half the sample, the Fabry-Perot Hα images show loops and filaments with sizes of one to a few kpc. The Echelle spectra taken through the loops and filaments show kinematics consistent with expanding bubble-like structures. We describe these data, and present seven dwarfs in our sample that have the strongest evidence of outflows.

Mapping of quantitative trait loci (QTL) for production, resistance and tolerance traits in Salix. Final Report

Energy Technology Data Exchange (ETDEWEB)

Roennberg-Waestljung, Ann Christin; Bertholdsson, Nils-Ove; Glynn, Carolyn; Weih, Martin; Aahman, Inger [SLU, Uppsala (Sweden). Dept. of Plant Biology and Forest Genetics

2004-05-01

Quantitative trait loci (QTL) for growth traits, water use efficiency and tolerance/resistance against metals and herbivores have been identified. A hybrid F2 population originating from a cross between a Salix dasyclados-clone (SW901290) and a S. viminalis-clone ('Jorunn') was used for the different studies in this project. The growth response was analyzed in a greenhouse experiment with two water treatments, normal and drought. In addition, three field experiments with contrasting soils and climates were established. QTL specific for each treatment or field environment but also QTL stable over the treatments or field environments were detected. Each QTL explained from 8 to 29 % of the phenotypic variation depending on trait, treatment or field environment. Clusters of QTL for different traits were mapped indicating a common genetic base or tightly-linked QTL. Stable QTL identified for dryweight can be useful tools for early selection in Salix. In a separate greenhouse experiment, with a subset of ten genotypes from the F2 population, we show that genotype is more important than irrigation treatment for production of phenolic substances as well as for resistance to herbivory by P vulgatissima.

Evidence for the Translocation of Gibberellin A_3 and Gibberellin-Like Substances in Grafts between Normal, Dwarf_1 and Dwarf_5 Seedlings of Zea mays L.

OpenAIRE

M., Katsumi; D.E., Foard; B.O., Phinney; Biology Department, International Christian University; Department of Botany and Plant Pathology, Purdue University; Department of Biology, University of California

1983-01-01

Approach grafts were made between the cut surfaces of mesocotyls from normal and dwarf seedlings of Zea mays L. (maize). The dwarfs were the non-allelic single gene gibberellin mutants, dwarf_1 and dwarf_5. The graft combinations were normal-normal, normal-dwarf_1, normal-dwarf_5, dwarf_1-dwarf_1, dwarf_5-dwarf_5, and dwarf_1-dwarf_5. The grafts were used to demonstrate the movement of gibberellin-like substances across the union. GA_3, added to one member of the graft, resulted in leaf-sheat...

PREFACE: 16th European White Dwarfs Workshop

Science.gov (United States)

Garcia-Berro, Enrique; Hernanz, Margarita; Isern, Jordi; Torres, Santiago

2009-07-01

The 16th European Workshop on White Dwarfs was held in Barcelona, Spain, from 30 June to 4 July 2008 at the premises of the UPC. Almost 120 participants from Europe (France, Germany, United Kingdom, Italy, and several others), America (USA, Canada, Argentina, Brazil, and Chile), and other continents (Australia, South Africa, . . . ) attended the workshop. Among these participants were the most relevant specialists in the field. The topics covered by the conference were: White dwarf structure and evolution Progenitors and Planetary Nebulae White dwarfs in binaries: cataclysmic variables, double degenerates and other binaries White dwarfs, dust disks and planetary systems Atmospheres, chemical composition, magnetic fields Variable white dwarfs White dwarfs in stellar clusters and the halo White Dwarfs as SNIa progenitors The programme included 54 talks, and 45 posters. The oral presentations were distributed into the following sessions: Luminosity function, mass function and populations White dwarf structure and evolution White dwarf ages White dwarf catalogs and surveys Central stars of planetary nebulae Supernovae progenitors White dwarfs in novae and CVs Physical processes in white dwarfs and magnetic white dwarfs Disks, dust and planets around white dwarfs Pulsating white dwarfs Additionally we had a special open session about Spitzer and white dwarfs. The Proceedings of the 16th European Workshop on White Dwarfs are representative of the current state-of-the-art of the research field and include new and exciting results. We acknowledge the very positive attitude of the attendants to the workshop, which stimulated very fruitful discussions that took place in all the sessions and after the official schedule. Also, the meeting allowed new collaborations tp start that will undoubtedly result in significant advances in the research field. We also acknowledge the willingness of the participants to deliver their contributions before the final deadline. We sincerely

SpeX Spectroscopy of Unresolved Very Low-Mass Binaries. I. Identification of Seventeen Candidate Binaries Straddling the L Dwarf/T Dwarf Transition

OpenAIRE

Burgasser, Adam J.; Cruz, Kelle L.; Cushing, Michael C.; Gelino, Christopher R.; Looper, Dagny L.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Reid, I. Neill

2009-01-01

We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13581 pairs of absolute flux-ca...

Seismic modelling of coal bed methane strata, Willow Creek, Alberta

Energy Technology Data Exchange (ETDEWEB)

Richardson, S.E.; Mayer, R.; Lawton, D.C.; Langenberg, W. [Consortium for Research in Elastic Wave Exploration Seismology, Calgary, AB (Canada)

2001-07-01

The purpose is to determine the feasibility of applying high- resolution reflection seismic surveying to coalbed methane (CBM) exploration and development. Numerical reflection seismic methods are examined for measuring the mapping continuity and coherence of coal zones. Numerical modelling of a coal zone in Upper Cretaceous sediments near Willow Creek, Alberta indicates that seismic data that is predominantly of 100 Hz is required to map the coal zone and lateral facies variations within the deposit. For resolution of individual coal seams, a central frequency >150 Hz would be needed. 26 refs., 17 figs., 3 tabs.

Quantum liquid signatures in dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Gabadadze, Gregory; Pirtskhalava, David, E-mail: gg32@nyu.edu, E-mail: dmp371@nyu.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003 (United States)

2009-05-15

We develop further the proposal of arXiv:0806.3692 that a new state of matter - charged condensate of spin-0 nuclei - may exist in helium-core dwarf stars. The charged condensate and its fluctuations are described by an effective field theory Lagrangian. The spectrum of bosonic fluctuations is gapped, while electrons, at temperatures of interest, give rise to gapless excitations near the Fermi surface. These properties determine the evolution of the dwarfs with condensed cores. In particular, we show that such dwarf stars would cool significantly faster than their crystallized counterparts. As a result, the luminosity function for the helium-core dwarfs will have a sharp drop-off after the condensation. It is tempting to interpret the recently discovered abrupt termination of a sequence of 24 helium-core dwarf candidates in NGC 6397 as a signature of the charged condensation.

Milky Way red dwarfs in the BoRG survey; galactic scale-height and the distribution of dwarf stars in WFC3 imaging

International Nuclear Information System (INIS)

Holwerda, B. W.; Bouwens, R.; Trenti, M.; Clarkson, W.; Sahu, K.; Bradley, L.; Stiavelli, M.; Pirzkal, N.; Ryan, R.; De Marchi, G.; Andersen, M.

2014-01-01

We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin 2 ) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r 50 ), a near-infrared J – H, G – J color region where M-dwarfs are found, and a V – J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m F125W < 24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z 0 = 3-4 kpc) and later types M5 and above in the thin disk (z 0 = 0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of high-redshift galaxies

Milky Way red dwarfs in the BoRG survey; galactic scale-height and the distribution of dwarf stars in WFC3 imaging

Energy Technology Data Exchange (ETDEWEB)

Holwerda, B. W.; Bouwens, R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Trenti, M. [Kavli Institute for Cosmology and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Clarkson, W. [Department of Natural Sciences College of Arts, Sciences and Letters, University of Michigan-Dearborn 4901 Evergreen Road, Dearborn, MI 48128 (United States); Sahu, K.; Bradley, L.; Stiavelli, M.; Pirzkal, N.; Ryan, R. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); De Marchi, G. [European Space Agency, ESA-ESTEC, Keplerlaan 1, 2200 AG Noordwijk (Netherlands); Andersen, M., E-mail: holwerda@strw.leidenuniv.nl [UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, F-38041 Grenoble (France)

2014-06-10

We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin{sup 2}) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r {sub 50}), a near-infrared J – H, G – J color region where M-dwarfs are found, and a V – J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of m {sub F125W} < 24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z {sub 0} = 3-4 kpc) and later types M5 and above in the thin disk (z {sub 0} = 0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of

An overview of white dwarf stars

Directory of Open Access Journals (Sweden)

Charpinet S.

2013-03-01

Full Text Available We present a brief summary of what is currently known about white dwarf stars, with an emphasis on their evolutionary and internal properties. As is well known, white dwarfs represent the end products of stellar evolution for the vast majority of stars and, as such, bear the signatures of past events (such as mass loss, mixing phases, loss and redistribution of angular momentum, and thermonuclear burning that are of essential importance in the evolution of stars in general. In addition, white dwarf stars represent ideal testbeds for our understanding of matter under extreme conditions, and work on their constitutive physics (neutrino production rates, conductive and radiative opacities, interior liquid/solid equations of state, partially ionized and partially degenerate envelope equations of state, diffusion coefficients, line broadening mechanisms is still being actively pursued. Given a set of constitutive physics, cooling white dwarfs can be used advantageously as cosmochronometers. Moreover, the field has been blessed by the existence of four distinct families of pulsating white dwarfs, each mapping a different evolutionary phase, and this allows the application of the asteroseismological method to probe and test their internal structure and evolutionary state. We set the stage for the reviews that follow on cooling white dwarfs as cosmochronometers and physics laboratories, as well as on the properties of pulsating white dwarfs and the asteroseismological results that can be inferred.

A CROSS-MATCH OF 2MASS AND SDSS. II. PECULIAR L DWARFS, UNRESOLVED BINARIES, AND THE SPACE DENSITY OF T DWARF SECONDARIES

International Nuclear Information System (INIS)

Geissler, Kerstin; Metchev, Stanimir; Kirkpatrick, J. Davy; Berriman, G. Bruce; Looper, Dagny

2011-01-01

We present the completion of a program to cross-correlate the Sloan Digital Sky Survey Data Release 1 (SDSS DR1) and Two-Micron All-Sky Survey (2MASS) Point Source Catalog in search for extremely red L and T dwarfs. The program was initiated by Metchev and collaborators, who presented the findings on all newly identified T dwarfs in SDSS DR1 and estimated the space density of isolated T0-T8 dwarfs in the solar neighborhood. In the current work, we present most of the L dwarf discoveries. Our red-sensitive (z - J ≥ 2.75 mag) cross-match proves to be efficient in detecting peculiarly red L dwarfs, adding two new ones, including one of the reddest known L dwarfs. Our search also nets a new peculiarly blue L7 dwarf and, surprisingly, two M8 dwarfs. We further broaden our analysis to detect unresolved binary L or T dwarfs through spectral template fitting to all L and T dwarfs presented here and in the earlier work by Metchev and collaborators. We identify nine probable binaries, six of which are new and eight harbor likely T dwarf secondaries. We combine this result with current knowledge of the mass ratio distribution and frequency of substellar companions to estimate an overall space density of 0.005-0.05 pc -3 for individual T0-T8 dwarfs.

Microbial expression profiles in the rhizosphere of willows depend on soil contamination

OpenAIRE

Yergeau, Etienne; Sanschagrin, Sylvie; Maynard, Christine; St-Arnaud, Marc; Greer, Charles W

2013-01-01

The goal of phytoremediation is to use plants to immobilize, extract or degrade organic and inorganic pollutants. In the case of organic contaminants, plants essentially act indirectly through the stimulation of rhizosphere microorganisms. A detailed understanding of the effect plants have on the activities of rhizosphere microorganisms could help optimize phytoremediation systems and enhance their use. In this study, willows were planted in contaminated and non-contaminated soils in a greenh...

Larch Dwarf Mistletoe (FIDL)

Science.gov (United States)

Jerome S. Beatty; Gregory M. Filip; Robert L. Mathiason

1997-01-01

Larch dwarf mistletoe (Arceuthobium laricis (Piper) St. John) is a common and damaging parasite of western larch (Larix occidentalis Nutt.) in the Pacific Northwest and southern British Columbia. Larch dwarf mistletoe occurs commonly throughout the range of western larch in British Columbia, northern and central Idaho, western Montana and east of the Cascades in...

Star Formation Histories of Nearby Dwarf Galaxies

OpenAIRE

Grebel, Eva K.

2000-01-01

Properties of nearby dwarf galaxies are briefly discussed. Dwarf galaxies vary widely in their star formation histories, the ages of their subpopulations, and in their enrichment history. Furthermore, many dwarf galaxies show evidence for spatial variations in their star formation history; often in the form of very extended old populations and radial gradients in age and metallicity. Determining factors in dwarf galaxy evolution appear to be both galaxy mass and environment. We may be observi...

Porous Carbon with Willow-Leaf-Shaped Pores for High-Performance Supercapacitors.

Science.gov (United States)

Shi, Yanhong; Zhang, Linlin; Schon, Tyler B; Li, Huanhuan; Fan, Chaoying; Li, Xiaoying; Wang, Haifeng; Wu, Xinglong; Xie, Haiming; Sun, Haizhu; Seferos, Dwight S; Zhang, Jingping

2017-12-13

A novel kind of biomass-derived, high-oxygen-containing carbon material doped with nitrogen that has willow-leaf-shaped pores was synthesized. The obtained carbon material has an exotic hierarchical pore structure composed of bowl-shaped macropores, willow-leaf-shaped pores, and an abundance of micropores. This unique hierarchical porous structure provides an effective combination of high current densities and high capacitance because of a pseudocapacitive component that is afforded by the introduction of nitrogen and oxygen dopants. Our synthetic optimization allows further improvements in the performance of this hierarchical porous carbon (HPC) material by providing a high degree of control over the graphitization degree, specific surface area, and pore volume. As a result, a large specific surface area (1093 m 2 g -1 ) and pore volume (0.8379 cm 3 g -1 ) are obtained for HPC-650, which affords fast ion transport because of its short ion-diffusion pathways. HPC-650 exhibits a high specific capacitance of 312 F g -1 at 1 A g -1 , retaining 76.5% of its capacitance at 20 A g -1 . Moreover, it delivers an energy density of 50.2 W h kg -1 at a power density of 1.19 kW kg -1 , which is sufficient to power a yellow-light-emitting diode and operate a commercial scientific calculator.

Plant Functional Traits Are More Consistent Than Plant Species on Periglacial Patterned Ground in the Rocky Mountains of Montana

Science.gov (United States)

Apple, M. E.; Ricketts, M. K.; Gallagher, J. H. R.

2017-12-01

Periglacial patterned ground exists as stripes and hexagons near glaciers and snowfields, some of which are former glaciers. The patterns are accentuated by profound differences in plant cover between the sloping surfaces, generally perceived as green, and the flat treads, generally perceived as brown but which are not devoid of plant life. On four sites in the Rocky Mountains of Montana we detected strong similarities in plant functional traits on the sloping surfaces of striped and hexagonal periglacial patterned ground. On Mt. Keokirk in the Pioneer Mountains, Kinnickinnick, Arctostaphylos uva-ursi, dominates narrow green stripes. On Goat Flat in the Pintler Mountains, Mountain Avens, Dryas octopetala, dominates the side walls of hexagonally patterned ground and narrow green stripes. At Glacier National Park, D. octopetala and the Arctic Willow, Salix arctica, co-dominate the green risers of widely-spaced striped periglacial patterned system at Siyeh Pass, while D. octopetala, S. arctica, and the Mountain Heather, Phyllodoce glanduliflora, co-dominate the green risers of the widely-spaced stripes of Piegan Pass. All four of these dictotyledonous angiosperm species are adventitiously-rooted dwarf shrubs with simple leaves. Of these, P. glanduliflora, A. uva-ursi and D. octopetala are evergreen. D. octopetala is symbiotic with N-fixing Frankia sp. All are mycorrhizal, although D. octopetala and S. arctica are ectomycorrhizal and P. glanduliflora and A. uva-ursi have ericaceous mycorrhizae. In contrast, dwarf shrubs are scarce on flat treads and within hexagons, which are chiefly inhabited by herbaceous, taprooted or rhizomatous, VAM angiosperms. As the green stripes and hexagon walls have greater plant cover, they likely have greater organic material due to leaf buildup and root turnover, anchor themselves and the soil with adventitious roots, their clonality suggests long lives, and N-fixing influences N dynamics of the periglacial patterned ground.

Biofuel or excavation? - Life cycle assessment (LCA) of soil remediation options

Energy Technology Data Exchange (ETDEWEB)

Suer, Pascal; Andersson-Skoeld, Yvonne [Swedish Geotechnical Institute, 58193 Linkoeping (Sweden)

2011-02-15

The environmental consequences of soil remediation through biofuel or through dig-and-dump were compared using life cycle assessment (LCA). Willow (Salix viminalis) was actually grown in-situ on a discontinued oil depot, as a phytoremediation treatment. These data were used for the biofuel remediation, while excavation-and-refill data were estimated from experience. The biofuel remediation had great environmental advantages compared to the ex situ excavation remediation. With the ReCiPe impact assessment method, which included biodiversity, the net environmental effect was even positive, in spite of the fact that the wood harvest was not utilised for biofuel production, but left on the contaminated site. Impact from the Salix viminalis cultivation was mainly through land use for the short rotation coppice, and through journeys of control personnel. The latter may be reduced when familiarity with biofuel as a soil treatment method increases. The excavation-and-refill remediation was dominated by the landfill and the transport of contaminated soil and backfill. (author)

Evolution models of helium white dwarf--main-sequence star merger remnants: the mass distribution of single low-mass white dwarfs

OpenAIRE

Zhang, Xianfei; Hall, Philip D.; Jeffery, C. Simon; Bi, Shaolan

2017-01-01

It is not known how single white dwarfs with masses less than 0.5Msolar -- low-mass white dwarfs -- are formed. One way in which such a white dwarf might be formed is after the merger of a helium-core white dwarf with a main-sequence star that produces a red giant branch star and fails to ignite helium. We use a stellar-evolution code to compute models of the remnants of these mergers and find a relation between the pre-merger masses and the final white dwarf mass. Combining our results with ...

Hemlock Dwarf Mistletoe (FIDL)

Science.gov (United States)

Paul E. Hennon; Jerome S. Beatty; Diane Hildebrand

2001-01-01

Hemlock dwarf mistletoe, Arceuthobium tsugense (Rosendahl) G.N. Jones, causes a serious disease of western hemlock and several other tree species along the Pacific Coast of North America. This small, seed-bearing plant lives exclusively as a parasite on living trees. Throughout its range, hemlock dwarf mistletoe occurs in patch-like patterns in the forests. Some...

Merging white dwarfs and thermonuclear supernovae.

Science.gov (United States)

van Kerkwijk, M H

2013-06-13

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.

A radio-pulsing white dwarf binary star.

Science.gov (United States)

Marsh, T R; Gänsicke, B T; Hümmerich, S; Hambsch, F-J; Bernhard, K; Lloyd, C; Breedt, E; Stanway, E R; Steeghs, D T; Parsons, S G; Toloza, O; Schreiber, M R; Jonker, P G; van Roestel, J; Kupfer, T; Pala, A F; Dhillon, V S; Hardy, L K; Littlefair, S P; Aungwerojwit, A; Arjyotha, S; Koester, D; Bochinski, J J; Haswell, C A; Frank, P; Wheatley, P J

2016-09-15

White dwarfs are compact stars, similar in size to Earth but approximately 200,000 times more massive. Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions and the resulting mass transfer can generate atomic line and X-ray emission, as well as near- and mid-infrared radiation if the white dwarf is magnetic. However, even in binaries, white dwarfs are rarely detected at far-infrared or radio frequencies. Here we report the discovery of a white dwarf/cool star binary that emits from X-ray to radio wavelengths. The star, AR Scorpii (henceforth AR Sco), was classified in the early 1970s as a δ-Scuti star, a common variety of periodic variable star. Our observations reveal instead a 3.56-hour period close binary, pulsing in brightness on a period of 1.97 minutes. The pulses are so intense that AR Sco's optical flux can increase by a factor of four within 30 seconds, and they are also detectable at radio frequencies. They reflect the spin of a magnetic white dwarf, which we find to be slowing down on a 10 7 -year timescale. The spin-down power is an order of magnitude larger than that seen in electromagnetic radiation, which, together with an absence of obvious signs of accretion, suggests that AR Sco is primarily spin-powered. Although the pulsations are driven by the white dwarf's spin, they mainly originate from the cool star. AR Sco's broadband spectrum is characteristic of synchrotron radiation, requiring relativistic electrons. These must either originate from near the white dwarf or be generated in situ at the M star through direct interaction with the white dwarf's magnetosphere.

White-dwarf-white-dwarf galactic background in the LISA data

International Nuclear Information System (INIS)

Edlund, Jeffrey A.; Tinto, Massimo; Krolak, Andrzej; Nelemans, Gijs

2005-01-01

LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy

Response of dwarf mistletoe-infested ponderosa pine to thinning: 2. Dwarf mistletoe propagation.

Science.gov (United States)

Lewis F. Roth; James W. Barrett

1985-01-01

Propagation of dwarf mistletoe in ponderosa pine saplings is little influenced by thinning overly dense stands to 250 trees per acre. Numerous plants that appear soon after thinning develop from formerly latent plants in the suppressed under-story. Subsequently, dwarf mistletoe propagates nearly as fast as tree crowns enlarge but the rate differs widely among trees....

Paleoseismology of the Nephi Segment of the Wasatch Fault Zone, Juab County, Utah - Preliminary Results From Two Large Exploratory Trenches at Willow Creek

Science.gov (United States)

Machette, Michael N.; Crone, Anthony J.; Personius, Stephen F.; Mahan, Shannon; Dart, Richard L.; Lidke, David J.; Olig, Susan S.

2007-01-01

In 2004, we identified a small parcel of U.S. Forest Service land at the mouth of Willow Creek (about 5 km west of Mona, Utah) that was suitable for trenching. At the Willow Creek site, which is near the middle of the southern strand of the Nephi segment, the WFZ has vertically displaced alluvial-fan deposits >6-7 m, forming large, steep, multiple-event scarps. In May 2005, we dug two 4- to 5-m-deep backhoe trenches at the Willow Creek site, identified three colluvial wedges in each trench, and collected samples of charcoal and A-horizon organic material for AMS (acceleration mass spectrometry) radiocarbon dating, and sampled fine-grained eolian and colluvial sediment for luminescence dating. The trenches yielded a stratigraphic assemblage composed of moderately coarse-grained fluvial and debris-flow deposits and discrete colluvial wedges associated with three faulting events (P1, P2, and P3). About one-half of the net vertical displacement is accommodated by monoclinal tilting of fan deposits on the hanging-wall block, possibly related to massive ductile landslide deposits that are present beneath the Willow Creek fan. The timing of the three surface-faulting events is bracketed by radiocarbon dates and results in a much different fault chronology and higher slip rates than previously considered for this segment of the Wasatch fault zone.

Phytoscreening and phytoextraction of heavy metals at Danish polluted sites using willow and poplar trees

DEFF Research Database (Denmark)

Nielsen, Mette Algreen; Trapp, Stefan; Rein, Arno

2014-01-01

The main purpose of this study was to determine typical concentrations of heavy metals (HM) in wood from willows and poplars, in order to test the feasibility of phytoscreening and phytoextraction of HM. Samples were taken from one strongly, one moderately, and one slightly polluted site and from...

A habitat overlap analysis derived from Maxent for Tamarisk and the South-western Willow Flycatcher

Science.gov (United States)

Patricia York; Paul Evangelista; Sunil Kumar; James Graham; Curtis Flather; Thomas Stohlgren

2011-01-01

Biologic control of the introduced and invasive, woody plant tamarisk (Tamarix spp, saltcedar) in south-western states is controversial because it affects habitat of the federally endangered South-western Willow Flycatcher (Empidonax traillii extimus). These songbirds sometimes nest in tamarisk where floodplain-level invasion replaces native habitats. Biologic control...

Pollen evidence for late pleistocene bering land bridge environments from Norton Sound, Northeastern Bering Sea, Alaska

Science.gov (United States)

Ager, T.A.; Phillips, R.L.

2008-01-01

After more than half a century of paleoenvironmental investigations, disagreements persist as to the nature of vegetation type and climate of the Bering land bridge (BLB) during the late Wisconsin (Sartan) glacial interval. Few data exist from sites on the former land bridge, now submerged under the Bering and Chukchi Seas. Two hypotheses have emerged during the past decade. The first, based on pollen data from Bering Sea islands and adjacent mainlands of western Alaska and Northeast Siberia, represents the likely predominant vegetation on the Bering land bridge during full-glacial conditions: graminoid-herb-willow tundra vegetation associated with cold, dry winters and cool, dry summer climate. The second hypothesis suggests that dwarf birch-shrub-herb tundra formed a broad belt across the BLB, and that mesic vegetation was associated with cold, snowier winters and moist, cool summers. As a step towards resolving this controversy, a sediment core from Norton Sound, northeastern Bering Sea was radiocarbon dated and analyzed for pollen content. Two pollen zones were identified. The older, bracketed by radiocarbon ages of 29,500 and 11,515 14C yr BP, contains pollen assemblages composed of grass, sedge, wormwood, willow, and a variety of herb (forb) taxa. These assemblages are interpreted to represent graminoid-herb-willow tundra vegetation that developed under an arid, cool climate regime. The younger pollen zone sediments were deposited about 11,515 14C yr BP, when rising sea level had begun to flood the BLB. This younger pollen zone contains pollen of birch, willow, heaths, aquatic plants, and spores of sphagnum moss. This is interpreted to represent a Lateglacial dwarf birch-heath-willow-herb tundra vegetation, likely associated with a wetter climate with deeper winter snows, and moist, cool summers. This record supports the first hypothesis, that graminoid-herb-willow tundra vegetation extended into the lowlands of the BLB during full glacial conditions of the

What fraction of white dwarfs are members of binary systems?

International Nuclear Information System (INIS)

Holberg, J B

2009-01-01

White dwarfs were originally discovered as the subordinate faint companions of bright nearby stars (i.e. Sirius B and 40 Eri B). Several general categories of binary systems involving white dwarfs are recognized: Sirius-like systems, where the white dwarf may be difficult to detect, binary systems containing white dwarfs and low mass stars, where the white dwarf is often readily discerned; and double degenerate systems. Different modes of white dwarf discovery influence our perception of both the overall binary fraction and the nature of these systems; proper motion surveys emphasize resolved systems, while photometric surveys emphasize unresolved systems containing relatively hot white dwarfs. Recent studies of the local white dwarf population offer some hope of achieving realistic estimates of the relative number of binary systems containing white dwarfs. A sample of 132 white dwarfs within 20 pc indicates that an individual white dwarf has a probability of 32 ± 8% of occurring within a binary or multiple star system.

Activity-induced radial velocity variation of M dwarf stars

DEFF Research Database (Denmark)

Andersen, Jan Marie; Korhonen, Heidi Helena

2012-01-01

that can drown out a planetary signature. Cool, low-mass M dwarf stars can be highly active, which can make detection of potentially habitable planets around these stars difficult. We investigate radial velocity variations caused by different activity (spot) patterns on M dwarf stars in order to determine...... the limits of detectability for small planets orbiting active M dwarfs. We report on our progress toward the aim of answering the following questions: What types of spot patterns are realistic for M dwarf stars? What effect will spots have on M dwarf RV measurements? Can jitter from M dwarf spots mimic...... planetary signals? What is the ideal observing wavelength to reduce M dwarf jitter?...

Application of two electrical methods for the rapid assessment of freezing resistance in Salix epichloro

Energy Technology Data Exchange (ETDEWEB)

Tsarouhas, V.; Kenney, W.A.; Zsuffa, L. [University of Toronto, Ontario (Canada). Faculty of Forestry

2000-09-01

The importance of early selection of frost-resistant Salix clones makes it desirable to select a rapid and accurate screening method for assessing freezing resistance among several genotypes. Two electrical methods, stem electrical impedance to 1 and 10 khz alternating current, and electrolyte leakage of leaf tissue, were evaluated for detecting freezing resistance on three North America Salix epichloro Michx., clones after subjecting them to five different freezing temperatures (-1, -2, -3, -4, and -5 deg C). Differences in the electrical impedance to 1 and 10 kHz, and the ratio of the impedance at the two frequencies (low/high) before and after the freezing treatment (DZ{sub low}, DZ{sub high}, and DZ{sub ratio}, respectively) were estimated. Electrolyte leakage was expressed as relative conductivity (RC{sub t}) and index of injury (IDX{sub t}). Results from the two methods, obtained two days after the freezing stress, showed that both electrical methods were able to detect freezing injury in S. eriocephala. However, the electrolyte leakage method detected injury in more levels of freezing stress (-3, -4, and -5 deg C) than the impedance (-4, and -5 deg C), it assessed clonal differences in S. eriocephala freezing resistance, and it was best suited to correlate electrical methods with the visual assessed freezing injury. No significant impedance or leakage changes were found after the -1 and -2 deg C freezing temperatures. (author)

NEW COOLING SEQUENCES FOR OLD WHITE DWARFS

International Nuclear Information System (INIS)

Renedo, I.; Althaus, L. G.; GarcIa-Berro, E.; Miller Bertolami, M. M.; Romero, A. D.; Corsico, A. H.; Rohrmann, R. D.

2010-01-01

We present full evolutionary calculations appropriate for the study of hydrogen-rich DA white dwarfs. This is done by evolving white dwarf progenitors from the zero-age main sequence, through the core hydrogen-burning phase, the helium-burning phase, and the thermally pulsing asymptotic giant branch phase to the white dwarf stage. Complete evolutionary sequences are computed for a wide range of stellar masses and for two different metallicities, Z = 0.01, which is representative of the solar neighborhood, and Z = 0.001, which is appropriate for the study of old stellar systems, like globular clusters. During the white dwarf cooling stage, we self-consistently compute the phase in which nuclear reactions are still important, the diffusive evolution of the elements in the outer layers and, finally, we also take into account all the relevant energy sources in the deep interior of the white dwarf, such as the release of latent heat and the release of gravitational energy due to carbon-oxygen phase separation upon crystallization. We also provide colors and magnitudes for these sequences, based on a new set of improved non-gray white dwarf model atmospheres, which include the most up-to-date physical inputs like the Lyα quasi-molecular opacity. The calculations are extended down to an effective temperature of 2500 K. Our calculations provide a homogeneous set of evolutionary cooling tracks appropriate for mass and age determinations of old DA white dwarfs and for white dwarf cosmochronology of the different Galactic populations.

Calorie restriction and dwarf mice in gerontological research.

Science.gov (United States)

McKee Alderman, J; DePetrillo, Michael A; Gluesenkamp, Angela M; Hartley, Antonia C; Verhoff, S Veronica; Zavodni, Katherine L; Combs, Terry P

2010-01-01

What aging process is delayed by calorie restriction (CR) and mutations that produce long-lived dwarf mice? From 1935 until 1996, CR was the only option for increasing the maximum lifespan of laboratory rodents. In 1996, the mutation producing the Ames dwarf mouse (Prop-1(-/-)) was reported to increase lifespan. Since 1996, other gene mutations that cause dwarfism or lower body weight have been reported to increase the lifespan of mice. The recent discovery of long-lived mutant dwarf mice provides an opportunity to investigate common features between CR and dwarf models. Both CR and dwarf mutations increase insulin sensitivity. Elevated insulin sensitivity reduces oxidative stress, a potential cause of aging. The elevation of liver insulin sensitivity by the hormone adiponectin in CR and long-lived dwarf mice can lower endogenous glucose production and raise fatty acid oxidation. Adiponectin reduction of plasma glucose in CR and long-lived dwarf mice can thereby lower age-related increases in oxidative damage and cancer. Copyright 2009 S. Karger AG, Basel.

Starbursts in Blue compact dwarf galaxies

International Nuclear Information System (INIS)

Thuan, T.X.

1987-01-01

We summarize all the arguments for a bursting mode of star formation in blue compact dwarf galaxies. We show in particular how spectral synthesis of far ultraviolet spectra of Blue compact dwarf galaxy constitutes a powerful way for studying the star formation history in these galaxies. Blue compact dwarf galaxy luminosity functions show jumps and discontinuities. These jumps act like fossil records of the star-forming bursts, helping us to count and date the bursts

Merging White Dwarfs and Thermonuclear Supernovae

OpenAIRE

van Kerkwijk, Marten H.

2012-01-01

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure, and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and our suggestion that these supernovae instead resul...

Rare White dwarf stars with carbon atmospheres

OpenAIRE

Dufour, P.; Liebert, James; Fontaine, G.; Behara, N.

2007-01-01

White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 msun and 8-10 msun, where msun is the mass of the Sun (more massive stars end their life as either black holes or neutron stars). The theory of stellar evolution predicts that the majority of white dwarfs have a core made of carbon and oxygen, which itself is surrounded by a helium layer and, for ~80 per cent of known white dwarfs, by an additional hydrogen layer. All white dwarfs...

Pulsating White Dwarfs in Cataclysmic Variables: The Marriage of ZZ Cet and Dwarf Nova

OpenAIRE

Warner, Brian; Woudt, Patrick A.

2003-01-01

There are now four dwarf novae known with white dwarf primaries that show large amplitude non-radial oscillations of the kind seen in ZZ Cet stars. We compare the properties of these stars and point out that by the end of the Sloan Digital Sky Survey more than 30 should be known.

The Effect of Trichoderma on Heavy Metal Mobility and Uptake by Miscanthus giganteus, Salix sp., Phalaris arundinacea, and Panicum virgatum

Directory of Open Access Journals (Sweden)

Malgorzata J. Kacprzak

2014-01-01

Full Text Available The effect of land application of biomaterials based on two strains of Trichoderma fungus on phytoremediation processes was studied. Six metals (Cd, Cr, Cu, Pb, Zn, and Ni were analysed in soil and soil leachate as well as in plant tissues. The translocation index (Ti and metal bioconcentration factors (BCF calculated for the inoculated plants were increased compared to the noninoculated control, except for Pb and Salix sp. Simultaneously, the mobilisation of metals in soil solution as an effect of biomaterials was noted. The highest values of Ti—339% (for Cr, 190% (for Ni, and 110% (for Cu—were achieved for the combination Miscanteus giganteus and Trichoderma MSO1. The results indicated that the application of fungus has positive effects on increasing the biomass, soil parameters (C, N, and P, and solubility of heavy metals in soil and therefore in enhancing phytoextraction for Miscanthus giganteus L., Panicum virgatum L., Phalaris arundinacea L., and Salix sp.

Pulsations in carbon-atmosphere white dwarfs: A new chapter in white dwarf asteroseismology

International Nuclear Information System (INIS)

Fontaine, G; Brassard, P; Dufour, P; Green, E M; Liebert, J

2009-01-01

We present some of the results of a survey aimed at exploring the asteroseismological potential of the newly-discovered carbon-atmosphere white dwarfs. We show that, in certains regions of parameter space, carbon-atmosphere white dwarfs may drive low-order gravity modes. We demonstrate that our theoretical results are consistent with the recent exciting discovery of luminosity variations in SDSS J1426+5752 and some null results obtained by a team of scientists at McDonald Observatory. We also present follow-up photometric observations carried out by ourselves at the Mount Bigelow 1.6-m telescope using the new Mont4K camera. The results of follow-up spectroscopic observations at the MMT are also briefly reported, including the surprising discovery that SDSS J1426+5752 is not only a pulsating star but that it is also a magnetic white dwarf with a surface field near 1.2 MG. The discovery of g-mode pulsations in SDSS J1426+5752 is quite significant in itself as it opens a fourth asteroseismological 'window', after the GW Vir, V777 Her, and ZZ Ceti families, through which one may study white dwarfs.

Seasonal dynamics and effects of nitrogen supply rate on nitrogen and carbohydrate reserves in cutting-derived Salix viminalis plants

Science.gov (United States)

Lars Bollmark; Lisa Sennerby-Forsse; Tom Ericsson

1999-01-01

Nurient storage is an important aspect of resprouting potential and production of Salix viminalis L., a pioneer species used for biomas production in weden. Seasonal dynamics of nitrogen (N), protien, soluble arbohydrates, starches, and lipids were studied in roots, cutting, stems, and leaves during a full growth cycle induced by varying photoperiod...

The RSA survey of dwarf galaxies, 1: Optical photometry

Science.gov (United States)

Vader, J. Patricia; Chaboyer, Brian

1994-01-01

We present detailed surface photometry, based on broad B-band charge coupled device (CCD) images, of about 80 dwarf galaxies. Our sample represents approximately 10% of all dwarf galaxies identified in the vicinity of Revised Shapley-Ames (RSA) galaxies on high resolution blue photographic plates, referred to as the RSA survey of dwarf galaxies. We derive global properties and radial surface brightness profiles, and examine the morphologies. The radial surface brightness profiles of dwarf galaxies, whether early or late type, display the same varieties in shape and complexity as those of classical giant galaxies. Only a few are well described by a pure r(exp 1/4) law. Exponential profiles prevail. Features typical of giant disk galaxies, such as exponential profiles with a central depression, lenses, and even, in one case (IC 2041), a relatively prominent bulge are also found in dwarf galaxies. Our data suggest that the central region evolves from being bulge-like, with an r(exp 1/4) law profile, in bright galaxies to a lens-like structure in dwarf galaxies. We prove detailed surface photometry to be a helpful if not always sufficient tool in investigating the structure of dwarf galaxies. In many cases kinematic information is needed to complete the picture. We find the shapes of the surface brightness profiles to be loosely associated with morphological type. Our sample contains several new galaxies with properties intermediate between those of giant and dwarf ellipticals (but no M32-like objects). This shows that such intermediate galaxies exist so that at least a fraction of early-type dwarf ellipticals is structurally related to early-type giants instead of belonging to a totally unrelated, disjunct family. This supports an origin of early-type dwarf galaxies as originally more massive systems that acquired their current morphology as a result of substantial, presumable supernova-driven, mass loss. On the other hand, several early-type dwarfs in our sample are

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2011-01-01

, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

The WFCAM transit survey and cool white dwarfs

Directory of Open Access Journals (Sweden)

Pinfield D.

2013-04-01

Full Text Available We present results from our search for cool white dwarfs in the WTS (WFCAM Transit Survey. Repeat observations starting in 2007 allowed to produce deep stacked images in J and measure proper motions. We combine this with deep optical imaging to select cool white dwarf candidates (Teff < 5000 K. About 27 cool white dwarf candidates with proper motions above 0.10 arcsec/yr were identified in one of the fields representing 1/8th of the survey area. Follow-up spectroscopy with the 10.2 m GTC telescope at La Palma confirmed the white dwarf status for all observed candidates. On-going work is being carried out to increase the sample of cool white dwarfs that will allow a more comprehensive study of the thick disk/halo white dwarf population.

A phytotoxicity test using transpiration of willows

DEFF Research Database (Denmark)

Trapp, Stefan; Zambrano, Kim Cecilia; Kusk, Kresten Ole

2000-01-01

is expressed as % decrease after 48 and 72 h or longer compared to the initial transpiration, divided by the transpiration of control plants. More toxicity parameters are growth and water use efficiency of the plants. The sensitivity of the test was evaluated with 3,5-dichlorophenol. EC50 values between 5......A short-term acute toxicity assay for willow trees growing in contaminated solution or in polluted soil was developed and tested. The test apparatus consists of an Erlenmeyer flask with a prerooted tree cutting growing in it. Growth and reduction of transpiration are used to determine toxicity....... Transpiration is closely related to photosynthesis and growth, but is easier and faster to measure and can be measured without disturbance of the test system. Plants are grown for 24 h in uncontaminated nutrient solution before the toxicant is added to determine the initial transpiration. The loss of weight...

Production and evaluation of dwarf and semi-dwarf winter wheat mutants

International Nuclear Information System (INIS)

Barabas, Z.; Kertesz, Z.

1984-01-01

A special research programme for evolving and evaluating dwarf wheat forms resistant to lodging was carried out at the Cereal Research Institute, Wheat Division, Szeged, Hungary. Seed lots of the two tall winter wheat varieties Jubilejnaya 50 and Partizanka were exposed to gamma ray of 60 Co. With irradiation of 15000 rad 60 Co all of M 1 plants grown in the field were almost totally destroyed in 1980 and about 50% in 1982. In the greenhouse the number of lost M 1 plants was insignificant. Only a small number of plants died both in the greenhouse and in the field when they were irradiated with 5000 rad. A treatment with this lower dose of irradiation probably may help the breeders in selection for winter hardiness. 97 dwarf wheat lines already established were analysed for height character by a top cross method using the variety Jubilejnaya 50 as a tester. Height data of the simultaneously grown parental as well as the F 1 and F 2 offsprings indicated that the majority of them were recessive, except 3 cases where dominant or semi-dominant dwarfism was observed. Noteworthy is the Mx 158 a new semi-dwarf variety candidate, 60-65 cm in height at normal stand and resistant to all the main diseases here (powdery mildew and rusts). Its grain and protein production per unit area is also very good. Some genetically lesser-known dwarf sources were investigated in a complete crossing diallel test. (author)

WISE Y dwarfs as probes of the brown dwarf-exoplanet connection

International Nuclear Information System (INIS)

Beichman, C.; Gelino, Christopher R.; Kirkpatrick, J. Davy; Cushing, Michael C.; Dodson-Robinson, Sally; Marley, Mark S.; Morley, Caroline V.; Wright, E. L.

2014-01-01

We have determined astrometric positions for 15 WISE-discovered late-type brown dwarfs (six T8-9 and nine Y dwarfs) using the Keck-II telescope, the Spitzer Space Telescope, and the Hubble Space Telescope. Combining data from 8 to 20 epochs we derive parallactic and proper motions for these objects, which puts the majority within 15 pc. For ages greater than a few Gyr, as suggested from kinematic considerations, we find masses of 10-30 M Jup based on standard models for the evolution of low-mass objects with a range of mass estimates for individual objects, depending on the model in question. Three of the coolest objects have effective temperatures ∼350 K and inferred masses of 10-15 M Jup . Our parallactic distances confirm earlier photometric estimates and direct measurements and suggest that the number of objects with masses below about 15 M Jup must be flat or declining, relative to higher mass objects. The masses of the coldest Y dwarfs may be similar to those inferred for recently imaged planet-mass companions to nearby young stars. Objects in this mass range, which appear to be rare in both the interstellar and protoplanetary environments, may both have formed via gravitational fragmentation—the brown dwarfs in interstellar clouds and companion objects in a protoplanetary disk. In both cases, however, the fact that objects in this mass range are relatively infrequent suggests that this mechanism must be inefficient in both environments.

Morphology and Structures of Nearby Dwarf Galaxies

Science.gov (United States)

Seo, Mira; Ann, HongBae

2015-08-01

We performed an analysis of the structure of nearby dwarf galaxies based on a 2-dimensional decomposition of galaxy images using GALFIT. The present sample consists of ~1,100 dwarf galaxies with redshift less than z = 0.01, which is is derived from the morphology catalog of the Visually classified galaxies in the local universe (Ann, Seo, and Ha 2015). In this catalog, dwarf galaxies are divided into 5 subtypes: dS0, dE, dSph, dEbc, dEblue with distinction of the presence of nucleation in dE, dSph, and dS0. We found that dSph and dEblue galaxies are fainter than other subtypes of dwarf galaxies. In most cases, single component, represented by the Sersic profile with n=1~1.5, well describes the luminosity distribution of dwarf galaxies in the present sample. However, a significant fraction of dS0, dEbc, and dEbue galaxies show sub-structures such as spiral arms and rings. We will discuss the morphology dependent evolutionary history of the local dwarf galaxies.

Comparison of Different Wood Species as Raw Materials for Bioenergy

Directory of Open Access Journals (Sweden)

Bojana Klašnja

2013-12-01

Full Text Available Background and Purpose: Most projections of the global energy use predict that biomass will be an important component of primary energy sources in the coming decades. Short rotation plantations have the potential to become an important source of renewable energy in Europe because of the high biomass yields, a good combustion quality as solid fuel, ecological advantages and comparatively low biomass production costs. Materials and Methods: In this study, the wood of black locust Robinia pseudoacacia, white willow Salix alba L., poplars Populus deltoides and Populus x euramericana cl.I-214, aged eight years were examined. Immediately after the felling, sample discs were taken to assess moisture content, ash content, the width of growth rings, wood densities and calorific values, according to the standard methodology. Results:The mean values of willow, poplar and black locust wood density were 341 kg/m3, 336 kg/m3 and 602 kg/m3,respectively. The average heating values of willow poplar and black locust wood were 18.599 MJ/kg, 18.564 MJ/kg and 21.196 MJ/kg, respectively. The FVI index (average values was higher for black locust (17.186 than for poplar and willow clones, which were similar: 11.312 and 11.422 respectively. Conclusions: Black locust wood with a higher density, calorific value and ash content compared to poplar and willow wood proved to be a more suitable raw material as RES. However, it is very important, from the aspect of the application of wood of these tree species as RES, to also consider the influence of the biomass yield per unit area of the plantations established as “energy plantations”.

High-dispersion observations of H-alpha in the suspected brown dwarf, white dwarf binary system G29-38

International Nuclear Information System (INIS)

Liebert, J.; Saffer, R.A.; Pilachowski, C.A.

1989-01-01

High-dispersion spectroscopy of the H-alpha absorption line of the cool DA white dwarf G29-38 is reported. This is the star for which a recently detected IR excess has been suggested to be due to a possible brown dwarf companion. Three echelle spectra show no evidence for radial-velocity variations larger than about 1.1 + or - 8.7 km/s and are used to derive a weighted heliocentric radial velocity of 33.7 + or - 4.3 kms/s for the white dwarf. The observations of a sharp absorption-line core restricts the possible rotation of the white dwarf to 40 km/s or less and ensures that any surface magnetic field has a strength of 100,000 G or less. These results make it unlikely that the DA white dwarf has previously been in a cataclysmic variable accretion phase. 18 references

HOW TO MAKE AN ULTRA-FAINT DWARF SPHEROIDAL GALAXY: TIDAL STIRRING OF DISKY DWARFS WITH SHALLOW DARK MATTER DENSITY PROFILES

International Nuclear Information System (INIS)

Łokas, Ewa L.; Kazantzidis, Stelios; Mayer, Lucio

2012-01-01

In recent years the Sloan Digital Sky Survey has unraveled a new population of ultra-faint dwarf galaxies (UFDs) whose origin remains a puzzle in the vicinity of the Milky Way (MW). Using a suite of collisionless N-body simulations, we investigate the formation of UFDs in the context of the tidal stirring model for the formation of dwarf spheroidal galaxies in the Local Group (LG). Our simulations are designed to reproduce the tidal interactions between MW-sized host galaxies and rotationally supported dwarfs embedded in 10 9 M ☉ dark matter (DM) halos. We explore a variety of inner density slopes ρ∝r –α for the dwarf DM halos, ranging from core-like (α = 0.2) to cuspy (α = 1), and different dwarf orbital configurations. Our experiments demonstrate that UFDs can be produced via tidal stirring of disky dwarfs on relatively tight orbits, consistent with a redshift of accretion by the host galaxy of z ∼ 1, and with intermediate values for the halo inner density slopes (ρ∝r –0.6 ). The inferred slopes are in excellent agreement with those resulting from both the modeling of the rotation curves of dwarf galaxies and recent cosmological simulations of dwarf galaxy formation. Comparing the properties of observed UFDs with those of their simulated counterparts, we find remarkable similarities in terms of basic observational parameters. We conclude that tidal stirring of rotationally supported dwarfs represents a viable mechanism for the formation of UFDs in the LG environment.

Progenitors of white dwarfs

International Nuclear Information System (INIS)

Drilling, J.S.; Schoenberner, D.

1985-01-01

Direct observational evidence is presented which indicates that the immediate progenitors of white dwarfs are the central stars of planetary nebulae (approximately 70%), other post-AGB objects (approximately 30%), and post-HB objects not massive enough to climb the AGB (approximately 0.3%). The combined birth rate for these objects is in satisfactory agreement with the death rate of main-sequence stars and the birth rate of white dwarfs

Explosive helium burning in white dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Khokhlov, A.M. (AN SSSR, Moscow. Astronomicheskij Sovet)

1984-04-01

Helium burning kinetics in white dwarfs has been considered at constant temperatures T >= 10/sup 9/ K and densities rho >10/sup 5/ g/cm/sup 3/. It is found, that helium detonation in white dwarfs does not lead to formation of light (A < 56) elements. Thus, helium white dwarf model for supernova 1 is inconsistent with observations.

Project DWARF - using eclipsing binaries for searching for exoplanets and brown dwarfs

Science.gov (United States)

Kudak, V.; Parimucha, Š.

2016-12-01

Project DWARF is a long-term observation campaign for about 60 selected eclipsing binaries aimed for detection of exoplanets or other objects (brown dwarfs) in low-mass detached binaries of different types (low-mass eclipsing binaries with M and K components, short-period binaries with sdB or sdO component, post-common-envelope systems containing a white dwarf). Existence of other bodies in systems are determined by analysing of O-C diagrams, constructed from observed minima times of binaries. Objects are selected with intention to determine minima with high precision. About 40 observatories are involved into the network at present time, mostly situated in Europe. The observations are made by small or middle class telescopes with apertures of 20-200 cm. In this contribution we give information about current status of the project, we present main goals and results of 4 years observations.

A Survey for Hα Emission from Late L Dwarfs and T Dwarfs

Science.gov (United States)

Pineda, J. Sebastian; Hallinan, Gregg; Kirkpatrick, J. Davy; Cotter, Garret; Kao, Melodie M.; Mooley, Kunal

2016-07-01

Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents. This emission provides the only window on magnetic fields in the coolest brown dwarfs and identifying additional benchmark objects is key to constraining dynamo theory in this regime. To this end, we conducted a new red optical (6300-9700 Å) survey with the Keck telescopes looking for Hα emission from a sample of late L dwarfs and T dwarfs. Our survey gathered optical spectra for 29 targets, 18 of which did not have previous optical spectra in the literature, greatly expanding the number of moderate-resolution (R ˜ 2000) spectra available at these spectral types. Combining our sample with previous surveys, we confirm an Hα detection rate of 9.2±{}2.13.5% for L and T dwarfs in the optical spectral range of L4-T8. This detection rate is consistent with the recently measured detection rate for auroral radio emission from Kao et al., suggesting that geometrical selection effects due to the beaming of the radio emission are small or absent. We also provide the first detection of Hα emission from 2MASS 0036+1821, previously notable as the only electron cyclotron maser radio source without a confirmed detection of Hα emission. Finally, we also establish optical standards for spectral types T3 and T4, filling in the previous gap between T2 and T5. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Polarized radiation in magnetic white dwarfs

International Nuclear Information System (INIS)

Rosi, L.A.; Zimmerman, R.L.; Kemp, J.C.

1976-01-01

A model for magnetic white dwarfs is proposed which attributes the partially polarized light to synchrotron radiation. The source of the radiation is relativistic electrons trapped in the magnetosphere of a white dwarf. The white dwarf's magnetic field is assumed to be dipolar. The Stokes parameters for the synchrotron radiation are tabulated as a function of frequency, observer's orientation, and energy and spatial distribution of the relativistic electrons. The results of the synchrotron calculations are applied to the polarization observations of Grw+70degree8247 and DQ Herculis. This model can account for the major features of the polarized radiation coming from these two magnetic white dwarfs. The calculations predict for Grw+70degree8247 that the surface magnetic field is B/sub s/approximately-less-than4 x 10 6 gauss, that the incident viewing angle is 45degreeapproximately-less-thantheta 0 approximately-less-than75degree, and that the electrons are trapped with nearly an isotropic distribution about the white dwarf. For DQ Herculis the surface magnetic field is B/sub s/approximately-less-than7 x 10 6 gauss and the trapped electrons are confined to a dislike region about the white dwarf. For both cases the density of electrons in the magnetosphere falls in the range of 10 5 approximately-less-thannapproximately-less-than10 7 cm -3 with energies of about 4--35 MeV

EVOLUTIONARY TRACKS OF TIDALLY STIRRED DISKY DWARF GALAXIES

International Nuclear Information System (INIS)

Lokas, Ewa L.; Kazantzidis, Stelios; Mayer, Lucio

2011-01-01

Using collisionless N-body simulations, we investigate the tidal evolution of late-type, rotationally supported dwarfs inside Milky Way sized host galaxies. Our study focuses on a wide variety of dwarf orbital configurations and initial structures. During the evolution, the disky dwarfs undergo strong mass loss, the stellar disks are transformed into spheroids, and rotation is replaced by random motions of the stars. Thus, the late-type progenitors are transformed into early-type dwarfs as envisioned by the tidal stirring model for the formation of dwarf spheroidal (dSph) galaxies in the Local Group. We determine the photometric properties of the dwarfs, including the total visual magnitude, the half-light radius, and the central surface brightness as they would be measured by an observer near the galactic center. Special emphasis is also placed on studying their kinematics and shapes. We demonstrate that the measured values are biased by a number of observational effects including the increasing angle of the observation cone near the orbital pericenter, the fact that away from the pericenter the tidal tails are typically oriented along the line of sight, and the fact that for most of the evolution the stellar components of the dwarfs are triaxial ellipsoids whose major axis tumbles with respect to the line of sight. Finally, we compare the measured properties of the simulated dwarfs to those of dwarf galaxies in the Local Group. The evolutionary tracks of the dwarfs in different parameter planes and the correlations between their different properties, especially the total magnitude and the surface brightness, strongly suggest that present-day dSph galaxies may have indeed formed from late-type progenitors as proposed by the tidal stirring scenario.

A DARK SPOT ON A MASSIVE WHITE DWARF

Energy Technology Data Exchange (ETDEWEB)

Kilic, Mukremin; Gianninas, Alexandros; Curd, Brandon; Wisniewski, John P. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Bell, Keaton J.; Winget, D. E.; Winget, K. I. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Brown, Warren R. [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States); Hermes, J. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Dufour, Patrick [Institut de recherche sur les exoplanétes (iREx), Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC H3C 3J7 (Canada)

2015-12-01

We present the serendipitous discovery of eclipse-like events around the massive white dwarf SDSS J152934.98+292801.9 (hereafter J1529+2928). We selected J1529+2928 for time-series photometry based on its spectroscopic temperature and surface gravity, which place it near the ZZ Ceti instability strip. Instead of pulsations, we detect photometric dips from this white dwarf every 38 minutes. Follow-up optical spectroscopy observations with Gemini reveal no significant radial velocity variations, ruling out stellar and brown dwarf companions. A disintegrating planet around this white dwarf cannot explain the observed light curves in different filters. Given the short period, the source of the photometric dips must be a dark spot that comes into view every 38 minutes due to the rotation of the white dwarf. Our optical spectroscopy does not show any evidence of Zeeman splitting of the Balmer lines, limiting the magnetic field strength to B < 70 kG. Since up to 15% of white dwarfs display kG magnetic fields, such eclipse-like events should be common around white dwarfs. We discuss the potential implications of this discovery on transient surveys targeting white dwarfs, like the K2 mission and the Large Synoptic Survey Telescope.

Effects of magnetic fields in white dwarfs

International Nuclear Information System (INIS)

Franzon, Bruno; Schramm, Stefan

2017-01-01

We perform calculations of white dwarfs endowed with strong magnetic fields. White dwarfs are the progenitors of supernova Type Ia explosions and they are widely used as candles to show that the Universe is expanding and accelerating. However, observations of ultraluminous supernovae have suggested that the progenitor of such an explosion should be a white dwarf with mass above the well-known Chandrasekhar limit ∼ 1.4 M⊙. In corroboration with other works, but by using a fully general relativistic framework, we obtained also strongly magnetized white dwarfs with masses M ∼ 2.0 M⊙. (paper)

Genetic identification of a dwarf mutant in cucumber ( Cucumis ...

African Journals Online (AJOL)

The dwarf (compact) plant architecture is an important trait in cucumber (Cucumis sativus L.) breeding. A dwarf type mutant was selected from the cucumbers. The morphological and reproductive characteristics of the dwarf were compared with the vine plants. The dwarf type of cucumbers is characterized by its short ...

The Potential Use of Agroforestry Community Gardens as a Sustainable Import-Substitution Strategy for Enhancing Food Security in Subarctic Ontario, Canada

Directory of Open Access Journals (Sweden)

Maren Oelbermann

2013-09-01

Full Text Available The high prevalence of food insecurity experienced by northern First Nations partially results from dependence on an expensive import-based food system that typically lacks nutritional quality and further displaces traditional food systems. In the present study, the feasibility of import substitution by Agroforestry Community Gardens (AFCGs as socio-ecologically and culturally sustainable means of enhancing food security was explored through a case study of Fort Albany First Nation in subarctic Ontario, Canada. Agroforestry is a diverse tree-crop agricultural system that has enhanced food security in the tropics and subtropics. Study sites were selected for long-term agroforestry research to compare Salix spp. (willow-dominated AFCG plots to a “no tree” control plot in Fort Albany. Initial soil and vegetative analysis revealed a high capacity for all sites to support mixed produce with noted modifications, as well as potential competitive and beneficial willow-crop interactions. It is anticipated that inclusion of willow trees will enhance the long-term productive capacity of the AFCG test plots. As an adaptable and dynamic system, AFCGs have potential to act as a more reliable local agrarian system and a refuge for culturally significant plants in high-latitude First Nation socio-ecological systems, which are particularly vulnerable to rapid cultural, climatic, and ecological change.

Microlensing Binaries with Candidate Brown Dwarf Companions

DEFF Research Database (Denmark)

Shin, I.-G; Han, C.; Gould, A.

2012-01-01

masses of the brown dwarf companions are 0.02 ± 0.01 M⊙ and 0.019 ± 0.002 M⊙ for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low-mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events...

Cd and Zn concentrations in small mammals and willow leaves on disposal facilities for dredged material

NARCIS (Netherlands)

Mertens, J.; Luyssaert, S.; Verbeeren, S.; Vervaeke, P; Lust, N

2001-01-01

Disposal sites for dredged material are often polluted with heavy metals. The uptake of Cd and Zn by small mammals and willow trees was assessed on three sites with a different pollution degree. Detailed soil sampling showed a huge variation in soil characteristics within the sites, typical for

Annual variations in the solar energy conversion efficiency in a willow coppice stand

International Nuclear Information System (INIS)

Noronha-Sannervik, A.; Kowalik, P.

2003-01-01

Productivity of an experimental willow coppice forest located at Uppsala, Sweden, was monitored between 1985 and 1994. The 2.7 ha stand was planted in 1984 with a density of 20 000 cuttings per ha and was harvested three times. During the monitored period, the annual stem wood production and the cumulated values of total solar radiation during the growing season, were measured. The conversion of incoming solar radiation into stem biomass was evaluated and the results show that the solar energy conversion efficiency (ECE), for the first and fourth year of the cutting cycle, is, on average, 64% of the ECE for the second and third year of the cutting cycle. It is discussed that the low ECE of 1-year-old shoots is related to a delay in leaf canopy development at the beginning of the growing season and lack of weed control after harvest. For the 4-years-old shoots, the low ECE, is believed to be related to the increased shoot and stool mortality caused by the self-thinning process ongoing in the willow stand. It is recommended that the harvesting interval should be based on the specific development of the stand and more attention should be paid to weed control, especially in the first growing season after harvest

The use of short rotation willows and poplars for the recycling of saline waste waters

Science.gov (United States)

Jaconette Mirck; Ronald S. Jr. Zalesny; Ioannis Dimitriou; Jill A. Zalesny; Timothy A. Volk; Warren E. Mabee

2009-01-01

The production of high-salinity waste waters by landfills and other waste sites causes environmental concerns. This waste water often contains high concentrations of sodium and chloride, which may end up in local ground and surface waters. Vegetation filter systems comprised of willows and poplars can be used for the recycling of saline waste water. These vegetation...

Dry matter losses and quality changes during short rotation coppice willow storage in chip or rod form.

Science.gov (United States)

Whittaker, Carly; Yates, Nicola E; Powers, Stephen J; Misselbrook, Tom; Shield, Ian

2018-05-01

This study compares dry matter losses and quality changes during the storage of SRC willow as chips and as rods. A wood chip stack consisting of approximately 74 tonnes of fresh biomass, or 31 tonnes dry matter (DM) was built after harvesting in the spring. Three weeks later, four smaller stacks of rods with an average weight of 0.8 tonnes, or 0.4 tonnes DM were built. During the course of the experiment temperature recorders placed in the stacks found that the wood chip pile reached 60 °C within 10 days of construction, but the piles of rods remained mostly at ambient temperatures. Dry matter losses were calculated by using pre-weighed independent samples within the stacks and by weighing the whole stack before and after storage. After 6 months the wood chip stack showed a DM loss of between 19.8 and 22.6%, and mean losses of 23.1% were measured from the 17 independent samples. In comparison, the rod stacks showed an average stack DM loss of between 0 and 9%, and between 1.4% and 10.6% loss from the independent samples. Analysis of the stored material suggests that storing willow in small piles of rods produces a higher quality fuel in terms of lower moisture and ash content; however, it has a higher fine content compared to storage in chip form. Therefore, according to the two storage methods tested here, there may be a compromise between maximising the net dry matter yield from SRC willow and the final fine content of the fuel.

Maximum gravitational redshift of white dwarfs

International Nuclear Information System (INIS)

Shapiro, S.L.; Teukolsky, S.A.

1976-01-01

The stability of uniformly rotating, cold white dwarfs is examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordtvedt. The maximum central density and gravitational redshift of a white dwarf are determined as functions of five of the nine PPN parameters (γ, β, zeta 2 , zeta 3 , and zeta 4 ), the total angular momentum J, and the composition of the star. General relativity predicts that the maximum redshifts is 571 km s -1 for nonrotating carbon and helium dwarfs, but is lower for stars composed of heavier nuclei. Uniform rotation can increase the maximum redshift to 647 km s -1 for carbon stars (the neutronization limit) and to 893 km s -1 for helium stars (the uniform rotation limit). The redshift distribution of a larger sample of white dwarfs may help determine the composition of their cores

Axion cooling of white dwarfs

OpenAIRE

Isern, J.; Catalan, S.; Garcia--Berro, E.; Salaris, M.; Torres, S.

2013-01-01

The evolution of white dwarfs is a simple gravothermal process. This process can be tested in two ways, through the luminosity function of these stars and through the secular variation of the period of pulsation of those stars that are variable. Here we show how the mass of the axion can be constrained using the white dwarf luminosity function.

THE NIRSPEC ULTRACOOL DWARF RADIAL VELOCITY SURVEY

International Nuclear Information System (INIS)

Blake, Cullen H.; Charbonneau, David; White, Russel J.

2010-01-01

We report the results of an infrared Doppler survey designed to detect brown dwarf and giant planetary companions to a magnitude-limited sample of ultracool dwarfs. Using the NIRSPEC spectrograph on the Keck II telescope, we obtained approximately 600 radial velocity (RV) measurements over a period of six years of a sample of 59 late-M and L dwarfs spanning spectral types M8/L0 to L6. A subsample of 46 of our targets has been observed on three or more epochs. We rely on telluric CH 4 absorption features in Earth's atmosphere as a simultaneous wavelength reference and exploit the rich set of CO absorption features found in the K-band spectra of cool stars and brown dwarfs to measure RVs and projected rotational velocities. For a bright, slowly rotating M dwarf standard we demonstrate an RV precision of 50 m s -1 and for slowly rotating L dwarfs we achieve a typical RV precision of approximately 200 m s -1 . This precision is sufficient for the detection of close-in giant planetary companions to mid-L dwarfs as well as more equal mass spectroscopic binary systems with small separations (a +0.7 -0.6 Gyr, similar to that of nearby sun-like stars. We simulate the efficiency with which we detect spectroscopic binaries and find that the rate of tight (a +8.6 -1.6 %, consistent with recent estimates in the literature of a tight binary fraction of 3%-4%.

Nucleosynthesis in cold white dwarf explosions

International Nuclear Information System (INIS)

Canal, R.; Hernanz, M.

1986-01-01

Type I supernovae (SNI) are generally thought to be the main contributors to the galactic nucleosynthesis of iron-peak elements and their yields of intermediate-mass elements may also be important. We concentrate here upon a different class of models, based on the explosion of cold, massive, partially solid white dwarfs. We show that such white dwarfs must be relatively frequent among SNI progenitors and how their hydrodynamics upon ignition is very different from that of hotter, fluid white dwarfs. The implications for nucleosynthesis are briefly discussed and some preliminary results are presented

White dwarf models of supernovae and cataclysmic variables

International Nuclear Information System (INIS)

Nomoto, K.; Hashimoto, M.

1986-01-01

If the accreting white dwarf increases its mass to the Chandrasekhar mass, it will either explode as a Type I supernova or collapse to form a neutron star. In fact, there is a good agreement between the exploding white dwarf model for Type I supernovae and observations. We describe various types of evolution of accreting white dwarfs as a function of binary parameters (i.e,. composition, mass, and age of the white dwarf, its companion star, and mass accretion rate), and discuss the conditions for the precursors of exploding or collapsing white dwarfs, and their relevance to cataclysmic variables. Particular attention is given to helium star cataclysmics which might be the precursors of some Type I supernovae or ultrashort period x-ray binaries. Finally we present new evolutionary calculations using the updated nuclear reaction rates for the formation of O+Ne+Mg white dwarfs, and discuss the composition structure and their relevance to the model for neon novae. 61 refs., 14 figs

Is EG 50 a White or Strange Dwarf?

Science.gov (United States)

Hajyan, G. S.; Vartanyan, Yu. L.

2017-12-01

The time dependences of the luminosity of a white dwarf and four strange dwarfs with masses of 0.5 M (the mass of the white dwarf EG 50 with a surface temperature of 2.1·104 K) are determined taking neutrino energy losses into account. It was assumed that these configurations radiate only at the expense of thermal energy reserves. It is shown that the sources of thermal energy owing to nonequilibrium b-processes and the phenomenon of crystallization of electron-nuclear matter are insignificant in determining the cooling time of white and strange dwarfs with masses of 0.5 M⨀. It is shown that in this approximation the time dependences of the luminosity of white and strange dwarfs with masses of 0.5 M⨀ differ significantly only for surface temperatures TR≥7·104 K, so it is impossible to determine whether EG 50 is a white or strange dwarf based on the cooling time.

White dwarf evolution - Cradle-to-grave constraints via pulsation

Science.gov (United States)

Kawaler, Steven D.

1990-01-01

White dwarf evolution, particularly in the early phases, is not very strongly constrained by observation. Fortunately, white dwarfs undergo nonradial pulsation in three distinct regions of the H-R diagram. These pulsations provide accurate masses, surface compositional structure and rotation velocities, and help constrain other important physical properties. We demonstrate the application of the tools of stellar seismology to white dwarf evolution using the hot white dwarf star PG 1159-035 and the cool DAV (or ZZ Ceti) stars as examples. From pulsation studies, significant challenges to the theory of white dwarf evolution emerge.

Searching for chemical signatures of brown dwarf formation

Science.gov (United States)

Maldonado, J.; Villaver, E.

2017-06-01

Context. Recent studies have shown that close-in brown dwarfs in the mass range 35-55 MJup are almost depleted as companions to stars, suggesting that objects with masses above and below this gap might have different formation mechanisms. Aims: We aim to test whether stars harbouring massive brown dwarfs and stars with low-mass brown dwarfs show any chemical peculiarity that could be related to different formation processes. Methods: Our methodology is based on the analysis of high-resolution échelle spectra (R 57 000) from 2-3 m class telescopes. We determine the fundamental stellar parameters, as well as individual abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, and Zn for a large sample of stars known to have a substellar companion in the brown dwarf regime. The sample is divided into stars hosting massive and low-mass brown dwarfs. Following previous works, a threshold of 42.5 MJup was considered. The metallicity and abundance trends of the two subsamples are compared and set in the context of current models of planetary and brown dwarf formation. Results: Our results confirm that stars with brown dwarf companions do not follow the well-established gas-giant planet metallicity correlation seen in main-sequence planet hosts. Stars harbouring massive brown dwarfs show similar metallicity and abundance distribution as stars without known planets or with low-mass planets. We find a tendency of stars harbouring less-massive brown dwarfs of having slightly higher metallicity, [XFe/Fe] values, and abundances of Sc II, Mn I, and Ni I than the stars having the massive brown dwarfs. The data suggest, as previously reported, that massive and low-mass brown dwarfs might present differences in period and eccentricity. Conclusions: We find evidence of a non-metallicity dependent mechanism for the formation of massive brown dwarfs. Our results agree with a scenario in which massive brown dwarfs are formed as stars. At high metallicities, the core

A low-temperature companion to a white dwarf star

Science.gov (United States)

Becklin, E. E.; Zuckerman, B.

1988-01-01

An infrared object located about 120 AU from the white dwarf GD165 has been discovered. With the exception of the possible brown dwarf companion to Giclas 29-38 reported last year, the companion to GD165 is the coolest (2100 K) dwarf star ever reported and, according to some theoretical models, it should be a substellar brown dwarf with a mass between 0.06 and 0.08 solar mass. These results, together with newly discovered low-mass stellar companions to white dwarfs, change the investigation of very low-mass stars from the study of a few chance objects to that of a statistical distribution. In particular, it appears that very low-mass stars and perhaps even brown dwarfs could be quite common in the Galaxy.

Willow and poplar for bioenergy on former cropland

DEFF Research Database (Denmark)

Georgiadis, Petros

and water demands of the trees. The water requirements of SRWCs are generally high, and high evapotranspiration rates in both SRC willow and SRF poplar decreased deep percolation, which along with low N concentrations led to low N leaching. Excessive N leaching was only observed when SRC was fertilized......Climate change is one of the 21st century’s greatest challenges and calls for immediate action through the implementation of mitigation strategies. A shift from fossil fuel to renewable energy is a key factor for reducing greenhouse gas emissions to the atmosphere, with bioenergy being...... the predominant sector of renewables in the current European and global energy markets. Dedicated energy crops, such as short rotation woody crops (SRWC), are promising bioenergy feedstock in southern Scandinavia due to their high yields. Such cropping systems have high demands for land, water, and nutrients...

The Living with a Red Dwarf / Goldiloks Program: The Activity-Rotation-Age Relationships of M and K Dwarfs

Science.gov (United States)

Engle, Scott; Guinan, Edward Francis

2018-01-01

Over the past several years, the database of M dwarfs with determined ages has continually expanded, allowing us to furnish Activity-Rotation-Age Relationships as part of the Living with a Red Dwarf program. We have now begun to expand this successful program to also cover K dwarfs - the Goldiloks program. Both M and K dwarfs suffer from the same limitation - due to their long lifetimes and very slow nuclear evolution, the best method for determining ages for a large number of M and K dwarf targets is through “magnetic tracers” such as X-UV activity levels and stellar rotation rates. We report on the current results of our relationships: deriving photometric rotation rates; gathering X-UV measures with HST, IUE Chandra and XMM (both proposed by us, and archival); and assessing their impacts on our understanding of the evolutions and habitability of these stellar types.We gratefully acknowledge the support from NSF/RUI Grant AST 1009903, Chandra Grant GO-13200633, HST Grants GO-12124X and GO-13020X.

Space distribution and physical properties of cool dwarf stars

International Nuclear Information System (INIS)

Staller, R.F.A.

1979-01-01

A new study of the space density of red dwarfs based on a sample of red dwarfs in a field of 238 square degrees towards the South Galactic Pole is presented. A blink survey using red and blue copies of Mount Palomar Sky Survey plates of a six square degrees field centered on the South Galactic Pole was performed and the results (approximately 2500 red objects) and the discussion of these results are presented. The time that elapsed before a black dwarf becomes invisible is estimated and is suggested that low-velocity red dwarfs could be explained by contracting black dwarfs. Based on theoretical considerations it can be shown that the existence of a large number of low-velocity stars is in serious conflict with criteria for the stability of the galactic disk. It is shown that if one also takes into account all generations of black dwarfs that are already invisible and therfore old, the mean velocity of all black dwarfs is much higher so that there is no conflict with theory. Luminosity functions of red and black dwarfs in several photometric passbands are calculated. (Auth.)

A possible magnetic DA white dwarf

International Nuclear Information System (INIS)

Wickramasinghe, D.T.; Bessell, M.S.

1976-01-01

The spectrum of a peculiar southern white dwarf suspect BPM 25114 is described. A possible magnetic interpretation suggests a DA white dwarf with a field of about 10 7 gauss. The star appears to be both a spectrum variable and perhaps light variable

Long-lived ames dwarf mice are resistant to chemical stressors.

Science.gov (United States)

Bokov, Alex F; Lindsey, Merry L; Khodr, Christina; Sabia, Marian R; Richardson, Arlan

2009-08-01

To probe the connection between longevity and stress resistance, we compared the sensitivity of Ames long-lived dwarf mice and control littermates with paraquat, diquat, and dobutamine. In young adult animals, 95% of male and 39% of female controls died after paraquat administration, but no dwarf animals died. When the experiment was repeated at an older age or a higher dosage of paraquat, dwarf mice still showed greater resistance. Dwarf mice also were more resistant to diquat; 80% of male and 60% of female controls died compared with 40% and 20% of dwarf mice, despite greater sensitivity of dwarf liver to diquat. Dwarf mice were also less sensitive to dobutamine-induced cardiac stress and had lower levels of liver and lung F(2)-isoprostanes. This is the first direct in vivo evidence that long-lived Ames dwarf mice have enhanced resistance to chemical insult, particularly oxidative stressors.

Sweating the small stuff: simulating dwarf galaxies, ultra-faint dwarf galaxies, and their own tiny satellites

Science.gov (United States)

Wheeler, Coral; Oñorbe, Jose; Bullock, James S.; Boylan-Kolchin, Michael; Elbert, Oliver D.; Garrison-Kimmel, Shea; Hopkins, Philip F.; Kereš, Dušan

2015-10-01

We present Feedback in Realistic Environment (FIRE)/GIZMO hydrodynamic zoom-in simulations of isolated dark matter haloes, two each at the mass of classical dwarf galaxies (Mvir ≃ 1010 M⊙) and ultra-faint galaxies (Mvir ≃ 109 M⊙), and with two feedback implementations. The resulting central galaxies lie on an extrapolated abundance matching relation from M⋆ ≃ 106 to 104 M⊙ without a break. Every host is filled with subhaloes, many of which form stars. Each of our dwarfs with M⋆ ≃ 106 M⊙ has 1-2 well-resolved satellites with M⋆ = 3-200 × 103 M⊙. Even our isolated ultra-faint galaxies have star-forming subhaloes. If this is representative, dwarf galaxies throughout the Universe should commonly host tiny satellite galaxies of their own. We combine our results with the Exploring the Local Volume in Simulations (ELVIS) simulations to show that targeting ˜ 50 kpc regions around nearby isolated dwarfs could increase the chances of discovering ultra-faint galaxies by ˜35 per cent compared to random pointings, and specifically identify the region around the Phoenix dwarf galaxy as a good potential target. The well-resolved ultra-faint galaxies in our simulations (M⋆ ≃ 3-30 × 103 M⊙) form within Mpeak ≃ 0.5-3 × 109 M⊙ haloes. Each has a uniformly ancient stellar population ( > 10 Gyr) owing to reionization-related quenching. More massive systems, in contrast, all have late-time star formation. Our results suggest that Mhalo ≃ 5 × 109 M⊙ is a probable dividing line between haloes hosting reionization `fossils' and those hosting dwarfs that can continue to form stars in isolation after reionization.

THE BROWN DWARF KINEMATICS PROJECT (BDKP). IV. RADIAL VELOCITIES OF 85 LATE-M AND L DWARFS WITH MagE

Energy Technology Data Exchange (ETDEWEB)

Burgasser, Adam J. [Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA 92093 (United States); Logsdon, Sarah E. [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Gagné, Jonathan [Institute for Research on Exoplanets (iREx), Université de Montréal, Département de Physique, C.P. 6128 Succ. Centre-ville, Montréal, QC H3C 3J7 (Canada); Bochanski, John J. [Rider University, 2083 Lawrenceville Road, Lawrenceville, NJ 08648 (United States); Faherty, Jaqueline K. [Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015 (United States); West, Andrew A. [Department of Astronomy, Boston University, 725 Commonwealth Avenue Boston, MA 02215 (United States); Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Schmidt, Sarah J. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Cruz, Kelle L., E-mail: aburgasser@ucsd.edu [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10034 (United States)

2015-09-15

Radial velocity measurements are presented for 85 late M- and L-type very low-mass stars and brown dwarfs obtained with the Magellan Echellette spectrograph. Targets primarily have distances within 20 pc of the Sun, with more distant sources selected for their unusual spectral energy distributions. We achieved precisions of 2–3 km s{sup −1}, and combined these with astrometric and spectrophotometric data to calculate UVW velocities. Most are members of the thin disk of the Galaxy, and velocity dispersions indicate a mean age of 5.2 ± 0.2 Gyr for sources within 20 pc. We find signficantly different kinematic ages between late-M dwarfs (4.0 ± 0.2 Gyr) and L dwarfs (6.5 ± 0.4 Gyr) in our sample that are contrary to predictions from prior simulations. This difference appears to be driven by a dispersed population of unusually blue L dwarfs which may be more prevalent in our local volume-limited sample than in deeper magnitude-limited surveys. The L dwarfs exhibit an asymmetric U velocity distribution with a net inward flow, similar to gradients recently detected in local stellar samples. Simulations incorporating brown dwarf evolution and Galactic orbital dynamics are unable to reproduce the velocity asymmetry, suggesting non-axisymmetric perturbations or two distinct L dwarf populations. We also find the L dwarfs to have a kinematic age-activity correlation similar to more massive stars. We identify several sources with low surface gravities, and two new substellar candidate members of nearby young moving groups: the astrometric binary DENIS J08230313–4912012AB, a low-probability member of the β Pictoris Moving Group; and 2MASS J15104786–2818174, a moderate-probability member of the 30–50 Myr Argus Association.

The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals

Science.gov (United States)

Kazantzidis, Stelios; Mayer, Lucio; Callegari, Simone; Dotti, Massimo; Moustakas, Leonidas A.

2017-02-01

A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Using N-body+SPH simulations, we investigate the dependence of this transformation mechanism on the gas fraction, f gas, in the disk of the progenitor dwarf. Our numerical experiments incorporate for the first time the combined effects of radiative cooling, ram-pressure stripping, star formation, supernova (SN) winds, and a cosmic UV background. For a given orbit inside the primary galaxy, rotationally supported dwarfs with gas fractions akin to those of observed dIrrs (f gas ≳ 0.5), demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs relative to their collisionless (f gas = 0) counterparts. We argue that the combination of ram-pressure stripping and SN winds causes the gas-rich dwarfs to respond more impulsively to tides, augmenting their transformation. When f gas ≳ 0.5, disky dwarfs on previously unfavorable low-eccentricity or large-pericenter orbits are still able to transform. On the widest orbits, the transformation is incomplete; the dwarfs retain significant rotational support, a relatively flat shape, and some gas, naturally resembling transition-type systems. We conclude that tidal stirring constitutes a prevalent evolutionary mechanism for shaping the structure of dwarf galaxies within the currently favored CDM cosmological paradigm.

The Effects of Ram-pressure Stripping and Supernova Winds on the Tidal Stirring of Disky Dwarfs: Enhanced Transformation into Dwarf Spheroidals

Energy Technology Data Exchange (ETDEWEB)

Kazantzidis, Stelios [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens, 15784 Zografos, Athens (Greece); Mayer, Lucio [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, CH-8057 Zürich (Switzerland); Callegari, Simone [Anthropology Institute and Museum, University of Zürich, CH-8057 Zürich (Switzerland); Dotti, Massimo [Università degli Studi di Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy); Moustakas, Leonidas A., E-mail: skazantzidis@phys.uoa.gr [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2017-02-10

A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Using N -body+SPH simulations, we investigate the dependence of this transformation mechanism on the gas fraction, f {sub gas}, in the disk of the progenitor dwarf. Our numerical experiments incorporate for the first time the combined effects of radiative cooling, ram-pressure stripping, star formation, supernova (SN) winds, and a cosmic UV background. For a given orbit inside the primary galaxy, rotationally supported dwarfs with gas fractions akin to those of observed dIrrs ( f {sub gas} ≳ 0.5), demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs relative to their collisionless ( f {sub gas} = 0) counterparts. We argue that the combination of ram-pressure stripping and SN winds causes the gas-rich dwarfs to respond more impulsively to tides, augmenting their transformation. When f {sub gas} ≳ 0.5, disky dwarfs on previously unfavorable low-eccentricity or large-pericenter orbits are still able to transform. On the widest orbits, the transformation is incomplete; the dwarfs retain significant rotational support, a relatively flat shape, and some gas, naturally resembling transition-type systems. We conclude that tidal stirring constitutes a prevalent evolutionary mechanism for shaping the structure of dwarf galaxies within the currently favored CDM cosmological paradigm.

A multiwavelength study of superoutbursts in dwarf novae

International Nuclear Information System (INIS)

Woerd, H.J. van der.

1987-01-01

Dwarf novae are stellar systems consisting of two stars which orbit around each other within a few hours. In dwarf novae one of the stars, which is a bit smaller and less massive than our sun, loses matter to a very compact and degenerated star: a white dwarf. This white dwarf has nearly the same mass as our sun but its radius is about a hundred times smaller. The process of mass transport was studied on the basis of observations with the Exosat-satelite (European X-ray Observatory satelite). 397 refs.; 50 figs.; 21 tabs

White dwarf evolution - Cradle-to-grave constraints via pulsation

International Nuclear Information System (INIS)

Kawaler, S.D.

1990-01-01

White dwarf evolution, particularly in the early phases, is not very strongly constrained by observation. Fortunately, white dwarfs undergo nonradial pulsation in three distinct regions of the H-R diagram. These pulsations provide accurate masses, surface compositional structure and rotation velocities, and help constrain other important physical properties. We demonstrate the application of the tools of stellar seismology to white dwarf evolution using the hot white dwarf star PG 1159-035 and the cool DAV (or ZZ Ceti) stars as examples. From pulsation studies, significant challenges to the theory of white dwarf evolution emerge. 44 refs

IUE spectrophotometry of the DA4 primary in the short-period white dwarf-red dwarf spectroscopic binary Case 1

Science.gov (United States)

Sion, E. M.; Guinan, E. F.; Wesemael, F.

1984-01-01

Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha red wing yields T(e) = 13,000 + or - 500 K. Possible interpretations of the 1400 A feature are reviewed. Case 1 is the coolest white dwarf found in a short-period, detached white dwarf-red dwarf binary, and its cooling time is consistent with estimates of the efficiency of angular momentum removal mechanisms in the phases subsequent to common envelope binary evolution.

Sampling procedure in a willow plantation for estimation of moisture content

DEFF Research Database (Denmark)

Nielsen, Henrik Kofoed; Lærke, Poul Erik; Liu, Na

2015-01-01

Heating value and fuel quality of wood is closely connected to moisture content. In this work the variation of moisture content (MC) of short rotation coppice (SRC) willow shoots is described for five clones during one harvesting season. Subsequently an appropriate sampling procedure minimising...... labour costs and sampling uncertainty is proposed, where the MC of a single stem section with the length of 10–50 cm corresponds to the mean shoot moisture content (MSMC) with a bias of maximum 11 g kg−1. This bias can be reduced by selecting the stem section according to the particular clone...

Conditions for accretion-induced collapse of white dwarfs