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Ingrid M. Parker - One of the best experts on this subject based on the ideXlab platform.
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chemical and mechanical control of the invasive shrub Cytisus scoparius in forest clearings in western washington usa
Invasive Plant Science and Management, 2020Co-Authors: Karen A. Haubensak, Sara Grove, Jeffrey Foster, Ingrid M. ParkerAbstract:We conducted a large-scale, multiple-year study in harvested areas of Douglas-fir ( Pseudotsuga menziesii [Mirbel] Franco) forests in western Washington, examining the effectiveness of control methods on the widespread invasive shrub Scotch broom [ Cytisus scoparius (L.) Link]. We tested both chemical and physical control methods, using three different approaches that are management relevant: (1) triclopyr, a POST herbicide, at different times of year and on different-sized plants; (2) cutting (or brushcutting) of mature individuals; and (3) scarification of soil surface to remove seedlings once versus multiple times. We measured initial mortality, seed germination, and percent cover of C. scoparius in plots for 3 yr following treatments. Triclopyr treatment resulted in greater mortality and reduced percent cover compared with all other treatments with the effect persisting for 2 yr after spraying. Further, triclopyr had the same effect on C. scoparius cover and mortality irrespective of time of year applied. Similar to soil scarification, triclopyr treatments resulted in a flush of seedlings, suggesting that removal of conspecific competitors and not soil disturbance per se promotes seed germination. Brushcutting was generally effective in reducing C. scoparius cover in the short term, but effects did not persist as long as triclopyr treatments, in part due to large differences in stump resprouting rates across sites. Soil scarification to remove seedlings, even over multiple years, did not result in reduced C. scoparius cover. Triclopyr is an effective approach for controlling both emerging and established stands of C. scoparius .
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disparate origins of bradyrhizobium symbionts for invasive populations of Cytisus scoparius leguminosae in north america
FEMS Microbiology Ecology, 2014Co-Authors: Kevin Horn, Ingrid M. Parker, Wanda Malek, Susana Rodriguezecheverria, Matthew A ParkerAbstract:To identify the geographic origin of nodule bacteria associated with invasion of the European legume Cytisus scoparius in the United States, isolates from 15 sites in six states were compared to > 200 Bradyrhizobium strains from indigenous legumes in the U.S., Mexico, Europe (six countries), Morocco, and Australia. Portions of five housekeeping loci (2849 bp) were sequenced, along with the nifD locus in the symbiosis island (SI) portion of the Bradyrhizobium chromosome. Bayesian phylogenetic analysis showed that North American C. scoparius symbionts had highly heterogeneous ancestry. Some were grouped into three distinct clades of European C. scoparius symbionts. One isolate had both housekeeping and SI genes belonging to a Bradyrhizobium clade from native legumes in western North America. Two other clades had mosaic ancestry: sequences for nifD as well as two other SI genes ( nifH , nodC ) were highly similar or identical to a C. scoparius strain from Spain, while their housekeeping loci belonged to American Bradyrhizobium clades. Thus, it appears that bacteria ancestrally associated with other North American legumes have evolved to utilize C. scoparius , by acquiring SI-region genes from European C. scoparius symbionts. Inoculation assays indicated that North American isolates were as competent as European strains in promoting plant growth, consistent with the findings on symbiont ancestry.
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soil changes accompanying invasion of the exotic shrub Cytisus scoparius in glacial outwash prairies of western washington usa
Plant Ecology, 2004Co-Authors: Karen A. Haubensak, Ingrid M. ParkerAbstract:Shrub encroachment of grassland is a global phenomenon that can cause substantial and rapid changes in soil nutrient levels and distribution. If the woody plants in question also have the capacity to fix nitrogen (N), the effects on soil nutrients may potentially be large. Cytisus scoparius L. Link (Scotch broom) is an introduced leguminous shrub from the Mediterranean region that colonizes open grasslands. We measured several properties of the surface soil (0-10 cm depth) across advancing fronts of Cytisus to assess changes in soil fertility associated with invasion in western Washington state (USA). Both total soil C and N increased (1.8% and 6.5%, respectively), resulting in a decrease in C to N ratio of 22.5 in uninvaded soils to 21.5 inside Cytisus patches. δ15N signature of surface soil did not clearly demonstrate a signal of N2-fixation across the Cytisus gradient. On the other hand, seven-day laboratory aerobic incubations demonstrated 3 and 2.4 times greater mineralization and nitrification rate, respectively, in Cytisus soils compared to uninvaded soils. Despite this increase in N availability, bioassay plants (Achillea millefolium) grown in uninvaded soils in the greenhouse were ∼ 30% larger than those grown in Cytisus-invaded soils, suggesting that Cytisus may have inhibitory effects on some plants growing in invaded soils. These results suggest that the impact of Cytisus invasion on grassland plant communities may be influenced or tempered by chemical or microbial effects on the soil other than simply increased labile N.
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invasion dynamics of Cytisus scoparius a matrix model approach
Ecological Applications, 2000Co-Authors: Ingrid M. ParkerAbstract:It is at the level of population dynamics that an invasion either fails or succeeds. By elucidating patterns of variation in population growth rates or demographic rates, it is possible to forge a connection between quantitative field data and theoretical ideas about invasiveness, invasibility, and rates of spread. Demographic models also provide a tool to guide control strategies for invasive pests. Here I report the results of a demographic study of Cytisus scoparius, an exotic shrub on the west coast of North America. I used matrix population models to describe demographic patterns in six populations (three in prairies and three in urban fields) and across advancing stages of invasion. At the edge of the invading front, all populations showed finite rates of increase (λ) >1; however, prairie populations were increasing much more rapidly than urban ones. While many individual vital rates differed between prairie and urban populations, Life Table Response Analysis revealed that seedling establishment mad...
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POLLINATOR LIMITATION OF Cytisus scoparius (SCOTCH BROOM), AN INVASIVE EXOTIC SHRUB
Ecology, 1997Co-Authors: Ingrid M. ParkerAbstract:Introductions of exotic species provide unique opportunities to study the demographic significance of species interactions, but as yet there is little information on how mutualistic interactions affect the invasion process. A shortage of mutualists could potentially limit the rate of population growth for an invading species. The introduced shrub Cytisus scoparius (Scotch broom, Leguminosae) is a pest plant on the west coast of North America. It produces flowers that are “tripped” open when pollinated and has a nearly obligatory relationship with resident bumble bees and honey bees. Experiments in the state of Washington showed that
Jorge Baonza - One of the best experts on this subject based on the ideXlab platform.
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are there predictable clines in plant pollinator interactions along altitudinal gradients the example of Cytisus scoparius l link in the sierra de guadarrama central spain
Diversity and Distributions, 2002Co-Authors: Juan E Malo, Jorge BaonzaAbstract:. We analyse the hypothesis that predictable gradients occur in plant–pollinator interactions along altitudinal gradients due to thermal constraints on insect body size and floral traits being selected for by pollinators. Pollinators’ size should follow Bergmann's rule in mountains (larger body size at higher altitudes) and selection should, in turn, lead to larger flower size at higher altitudes. The study focuses on the flower and pollinator size variation in 11 Cytisus scoparius populations located between 680 and 1300 m a.s.l., and on the relationship between flower size and pollination success of plants in each population. Significant differences among populations were found in flower size, pollinator size and fruiting success (anova, P < 0.001 in all cases). Regression models show that (i) pollinator size increases significantly with altitude, (ii) a parallel quadratic increase in flower size and (iii) a quadratic decrease in pollination success with altitude. Moreover, there is a tendency of plants with smaller flowers in each population to have a higher percentage of flowers initiating development into fruits (ancova, P < 0.05). All these observations support the presence of the predicted gradient in the studied species and they suggest the possibility of it to be somewhat common among plants that occupy large altitudinal ranges due to the simple basis on which it could be rooted.
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Are there predictable clines in plant–pollinator interactions along altitudinal gradients? The example of Cytisus scoparius (L.) Link in the Sierra de Guadarrama (Central Spain)
Diversity and Distributions, 2002Co-Authors: Juan E Malo, Jorge BaonzaAbstract:. We analyse the hypothesis that predictable gradients occur in plant–pollinator interactions along altitudinal gradients due to thermal constraints on insect body size and floral traits being selected for by pollinators. Pollinators’ size should follow Bergmann's rule in mountains (larger body size at higher altitudes) and selection should, in turn, lead to larger flower size at higher altitudes. The study focuses on the flower and pollinator size variation in 11 Cytisus scoparius populations located between 680 and 1300 m a.s.l., and on the relationship between flower size and pollination success of plants in each population. Significant differences among populations were found in flower size, pollinator size and fruiting success (anova, P
Encarna Velazquez - One of the best experts on this subject based on the ideXlab platform.
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ochrobactrum cytisi sp nov isolated from nodules of Cytisus scoparius in spain
International Journal of Systematic and Evolutionary Microbiology, 2007Co-Authors: Jose Luis Zurdopineiro, Raul Rivas, Martha E Trujillo, Nieves Vizcaino, Jose A Carrasco, Manuel Chamber, Antonio J Palomares, Pedro F Mateos, Eustoquio Martinezmolina, Encarna VelazquezAbstract:Two strains named ESC1T and ESC5 were isolated from nodules of Cytisus scoparius growing in a Spanish soil. Phylogenetic analysis of the 16S rRNA gene showed that these strains belong to the genus Ochrobactrum, their closest relatives being Ochrobactrum anthropi and Ochrobactrum lupini, with 100 and 99.9 % similarity to the respective type strains. Despite this high similarity, the results of DNA–DNA hybridization, phenotypic tests and fatty acid analyses showed that these strains represent a novel species of genus Ochrobactrum. The DNA–DNA hybridization values were respectively 70, 66 and 55 % with respect to O. lupini LUP21T, O. anthropi DSM 6882T and Ochrobactrum tritici DSM 13340T. The predominant fatty acids were C18 : 1 ω7c and C18 : 1 2-OH. Strains ESC1T and ESC5 were strictly aerobic and were able to reduce nitrate and to hydrolyse aesculin. They produced β-galactosidase and β-glucosidase and did not produce urease after 48 h incubation. The G+C content of strain ESC1T was 56.4 mol%. Both strains ESC1T and ESC5 contained nodD and nifH genes on megaplasmids that were related phylogenetically to those of rhizobial strains nodulating Phaseolus, Leucaena, Trifolium and Lupinus. From the results of this work, we propose that the strains isolated in this study be included in a novel species named Ochrobactrum cytisi sp. nov. The type strain is ESC1T (=LMG 22713T=CECT 7172T).
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Ochrobactrum cytisi sp. nov., isolated from nodules of Cytisus scoparius in Spain.
International journal of systematic and evolutionary microbiology, 2007Co-Authors: José Luis Zurdo-piñeiro, Raul Rivas, Martha E Trujillo, Nieves Vizcaino, Jose A Carrasco, Manuel Chamber, Pedro F Mateos, Antonio Palomares, Eustoquio Martínez-molina, Encarna VelazquezAbstract:Two strains named ESC1(T) and ESC5 were isolated from nodules of Cytisus scoparius growing in a Spanish soil. Phylogenetic analysis of the 16S rRNA gene showed that these strains belong to the genus Ochrobactrum, their closest relatives being Ochrobactrum anthropi and Ochrobactrum lupini, with 100 and 99.9 % similarity to the respective type strains. Despite this high similarity, the results of DNA-DNA hybridization, phenotypic tests and fatty acid analyses showed that these strains represent a novel species of genus Ochrobactrum. The DNA-DNA hybridization values were respectively 70, 66 and 55 % with respect to O. lupini LUP21(T), O. anthropi DSM 6882(T) and Ochrobactrum tritici DSM 13340(T). The predominant fatty acids were C(18 : 1)omega7c and C(18 : 1) 2-OH. Strains ESC1(T) and ESC5 were strictly aerobic and were able to reduce nitrate and to hydrolyse aesculin. They produced beta-galactosidase and beta-glucosidase and did not produce urease after 48 h incubation. The G+C content of strain ESC1(T) was 56.4 mol%. Both strains ESC1(T) and ESC5 contained nodD and nifH genes on megaplasmids that were related phylogenetically to those of rhizobial strains nodulating Phaseolus, Leucaena, Trifolium and Lupinus. From the results of this work, we propose that the strains isolated in this study be included in a novel species named Ochrobactrum cytisi sp. nov. The type strain is ESC1(T) (=LMG 22713(T)=CECT 7172(T)).
Nuria Pedrol - One of the best experts on this subject based on the ideXlab platform.
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Water-soluble phenolic acids and flavonoids involved in the bioherbicidal potential of Ulex europaeus and Cytisus scoparius
South African Journal of Botany, 2020Co-Authors: María Pardo-muras, Carolina G. Puig, X. Carlos Souto, Nuria PedrolAbstract:Abstract The use of allelopathic foliage incorporated into the soil as a bioherbicidal amendment is a promising weed management strategy which allows combining a cocktail of allelochemicals at low effective individual concentrations. In previous studies, the herbicidal potential of Ulex europaeus and Cytisus scoparius has been argued to be mediated by volatile organic compounds (VOCs). The present work undertakes for the first time the potential involvement of phenolic acids and flavonoids in the herbicidal bioactivity of both shrub species. Such compounds are those most likely to be released to soil water when the allelopathic foliage is incorporated into the soil. By dose-response in vitro bioassays of aqueous extracts, the flowering foliage of both shrub species was shown to release water-soluble compounds capable of inhibiting the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Far from expected, such phytotoxicity was enhanced when the aqueous extracts were applied to fresh soil. Via HPLC-DAD, 11 and 17 phenolic compounds were identified from U. europaeus and C. scoparius aqueous extracts, respectively, some of them cited for the first time in both species. The phenolic acids trans-cinnamic, p-coumaric, and ferulic, when were separately assayed in vitro at 1 mM, resulted phytotoxic to one or other target weed and physiological processes. However, except for the caffeic acid and vanillin, the phenolic acids lost effectiveness when applied at lower concentrations (0.1 or 0.01 mM). Otherwise, it was noteworthy that the flavonoids luteolin, ellagic acid, kaempferol, and naringenin were only phytotoxic when applied at low concentrations (≤0.1 mM). The proven herbicidal efficiency of the shrub foliage was argued to derive from the phytotoxicity of the water-soluble compounds assayed, and maybe from the combined or synergistic action with the VOCs emitted from the fresh plant material.
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Cytisus scoparius and ulex europaeus produce volatile organic compounds with powerful synergistic herbicidal effects
Molecules, 2019Co-Authors: Maria Pardomuras, Carolina G. Puig, Nuria PedrolAbstract:New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.
Juan E Malo - One of the best experts on this subject based on the ideXlab platform.
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potential ballistic dispersal of Cytisus scoparius fabaceae seeds
Australian Journal of Botany, 2004Co-Authors: Juan E MaloAbstract:Cytisus scoparius (L.) Link (Fabaceae) has a ballistic type of primary seed-dispersal mechanism in which its legumes dehisce suddenly when they dry. This paper presents an experimental approach to the measurement and modeling of distances reached by seeds under optimum dispersal conditions. Branchlets of the species carrying mature legumes were collected and attached to 1.20-m-high platforms on a flat roof terrace. For 2 weeks, daily measurements were made of distances attained by seeds ejected from legumes in the previous 24 h. Seeds were found at a distance of 2343 ± 113 mm (mean ± s.e., n = 245), with 10.2% of recorded distances greater than 5 m and some about 7 m. The mixture model fitted to the distances traveled by seeds allows the mathematical isolation of two underlying processes, the ballistic projection of seeds by dehiscent legumes (nearly 49% of seeds, reaching 3686 ± 1797 mm) and the barochorous dispersal of the remaining seeds in the platform environs (1254 ± 1254 mm). Modeling shows that seeds dispersed ballistically reach locations at some distance from the shrub crown, with low densities of sibling seeds—a potential advantage for the establishment of new individuals.
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are there predictable clines in plant pollinator interactions along altitudinal gradients the example of Cytisus scoparius l link in the sierra de guadarrama central spain
Diversity and Distributions, 2002Co-Authors: Juan E Malo, Jorge BaonzaAbstract:. We analyse the hypothesis that predictable gradients occur in plant–pollinator interactions along altitudinal gradients due to thermal constraints on insect body size and floral traits being selected for by pollinators. Pollinators’ size should follow Bergmann's rule in mountains (larger body size at higher altitudes) and selection should, in turn, lead to larger flower size at higher altitudes. The study focuses on the flower and pollinator size variation in 11 Cytisus scoparius populations located between 680 and 1300 m a.s.l., and on the relationship between flower size and pollination success of plants in each population. Significant differences among populations were found in flower size, pollinator size and fruiting success (anova, P < 0.001 in all cases). Regression models show that (i) pollinator size increases significantly with altitude, (ii) a parallel quadratic increase in flower size and (iii) a quadratic decrease in pollination success with altitude. Moreover, there is a tendency of plants with smaller flowers in each population to have a higher percentage of flowers initiating development into fruits (ancova, P < 0.05). All these observations support the presence of the predicted gradient in the studied species and they suggest the possibility of it to be somewhat common among plants that occupy large altitudinal ranges due to the simple basis on which it could be rooted.
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Are there predictable clines in plant–pollinator interactions along altitudinal gradients? The example of Cytisus scoparius (L.) Link in the Sierra de Guadarrama (Central Spain)
Diversity and Distributions, 2002Co-Authors: Juan E Malo, Jorge BaonzaAbstract:. We analyse the hypothesis that predictable gradients occur in plant–pollinator interactions along altitudinal gradients due to thermal constraints on insect body size and floral traits being selected for by pollinators. Pollinators’ size should follow Bergmann's rule in mountains (larger body size at higher altitudes) and selection should, in turn, lead to larger flower size at higher altitudes. The study focuses on the flower and pollinator size variation in 11 Cytisus scoparius populations located between 680 and 1300 m a.s.l., and on the relationship between flower size and pollination success of plants in each population. Significant differences among populations were found in flower size, pollinator size and fruiting success (anova, P
