| thermotolerance of leaf discs from four isoprene-emitting species is not enhanced by exposure to exogenous isoprene | the effects of exogenously supplied isoprene on chlorophyll fluorescence characteristics were examined in leaf discs of four isoprene-emitting plant species, kudzu (pueraria lobata [willd.] ohwi.), velvet bean (mucuna sp.), quaking aspen (populus tremuloides michx.), and pussy willow (salix discolor muhl). isoprene, supplied to the leaves at either 18 &mgr;l l-1 in compressed air or 21 &mgr;l l-1 in n2, had no effect on the temperature at which minimal fluorescence exhibited an upward inflection ... | 1999 | 10398717 |
| adult beetle grazing induces willow trichome defence against subsequent larval feeding. | induced increases in trichome density to grazing by herbivores have been suggested to increase plant resistance to future herbivore attack. in this paper we present results which show that plants of salix cinerea l. respond to adult leaf beetle (phratora vulgatissima l.) grazing by developing new leaves with an increased trichome density. the same plants are usually attacked again later in the season when the next generation of larvae hatches on the plants. the effect of the induced response was ... | 2003 | 12647188 |
| foliar concentrations of volunteer willows growing on polluted sediment-derived sites versus sites with baseline contamination levels. | many alluvial soils along navigable waterways are affected by disposal of dredged sediments or overbank sedimentation and contain metal concentrations that are elevated compared to baseline levels. uptake patterns for metals and other elements by several volunteer salix species growing on these sites were determined during a growing season in field plots and compared with the same species growing on soils with baseline contamination levels. for cd and zn, foliar concentrations were clearly highe ... | 2004 | 15054540 |
| the effect of hydrological regime on the metal bioavailability for the wetland plant species salix cinerea. | 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 le ... | 2005 | 15734590 |
| differences in cd and zn bioaccumulation for the flood-tolerant salix cinerea rooting in seasonally flooded contaminated sediments. | several authors suggest that a hydrological regime aiming at wetland creation is a potential management option that favours reducing bioavailability for metal-contaminated sites. 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 on a contaminated dredged sediment landfill (dsl) with variable duration of submersion was evaluated by measuring metal concen ... | 2004 | 15833256 |
| effect of submergence-emergence sequence and organic matter or aluminosilicate amendment on metal uptake by woody wetland plant species from contaminated sediments. | site-specific hydrological conditions affect the availability of trace metals for vegetation. in a greenhouse experiment, the effect of submersion on the metal uptake by the wetland plant species salix cinerea and populus nigra grown on a contaminated dredged sediment-derived soil and on an uncontaminated soil was evaluated. an upland hydrological regime for the polluted sediment caused elevated cd concentrations in leaves and cuttings for both species. emergence and soil oxidation after initial ... | 2007 | 16678320 |
| habitat difference in abundance of willow leaf beetle phratora vulgatissima (coleoptera: chrysomelidae): plant quality or natural enemies? | herbivorous insects are influenced by both 'bottom-up' forces mediated through host plants and 'top-down' forces from natural enemies. few studies have tried to evaluate the relative importance of the two forces in determining the abundance of insects. the leaf beetle phratora vulgatissima linnaeus sometimes occurs at high densities and severely damages the willow salix cinerea in forest habitats. for willows growing in open agricultural landscapes (farmland s. cinerea), the leaf beetle generall ... | 2006 | 17201981 |
| uptake of cd, zn and mn by willow increases during terrestrialisation of initially ponded polluted sediments. | metal concentration of plants growing on contaminated soils among other factors may depend on changes in the hydrological regime of the soil. foliar and stem metal concentrations in salix cinerea (grey sallow) were measured in 2 consecutive growing seasons on a submerged sediment-derived soil that underwent gradual terrestrialisation. foliar and stem cutting concentrations for cd, zn and mn increased on plots that were submerged during the first year, but emerged in the second year of monitoring ... | 2007 | 17207520 |
| pussy willow. salix discolor. | | 2007 | 17910321 |
| leaf trichome responses to herbivory in willows: induction, relaxation and costs. | to circumvent the inherent problem of discriminating between the cost of losing photosynthetic tissue and the cost of producing an inducible defence, the growth response of herbivore-damaged plants was compared with plants damaged mechanically to the same extent but without eliciting the defence. two experiments were conducted, studying the response of willows (salix cinerea) to damage by adult leaf beetles (phratora vulgatissima). in the first experiment, willows produced new leaves with an enh ... | 2008 | 18399933 |
| phenological sequences reveal aggregate life history response to climatic warming. | climatic warming is associated with organisms breeding earlier in the season than is typical for their species. in some species, however, response to warming is more complex than a simple advance in the timing of all life history events preceding reproduction. disparities in the extent to which different components of the reproductive phenology of organisms vary with climatic warming indicate that not all life history events are equally responsive to environmental variation. here, we propose tha ... | 2008 | 18409426 |
| opposing plant community responses to warming with and without herbivores. | if controls over primary productivity and plant community composition are mainly environmental, as opposed to biological, then global change may result in large-scale alterations in ecosystem structure and function. this view appears to be favored among investigations of plant biomass and community responses to experimental and observed warming. in far northern and arctic ecosystems, such studies predict increasing dominance of woody shrubs with future warming and emphasize the carbon (c)-seques ... | 2008 | 18719116 |
| influence of flooding and metal immobilising soil amendments on availability of metals for willows and earthworms in calcareous dredged sediment-derived soils. | 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, (nh4)2hpo4), 1% w/w mno, and 5% w/w caso4. in an additional treatment, the contaminated soil was subme ... | 2010 | 20347195 |