The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Jeanne C. Chambers - One of the best experts on this subject based on the ideXlab platform.
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Effects of a spring prescribed burn on the soil seed bank in sagebrush steppe exhibiting pinyon-juniper expansion
Western North American Naturalist, 2008Co-Authors: Elizabeth A. Allen, Jeanne C. Chambers, Robert S. NowakAbstract:Pinyon-juniper (Pinus monophylla-Juniperus osteosperma) woodlands are expanding into shrubsteppe ecosystems in western portions of the Great Basin. Often, highly competitive trees displace the understory, and pre- scribed fire is increasingly used as a restoration tool. To inform management decisions about post-fire recovery, we examined immediate and long-term (i.e., 2 growing seasons) responses of the germinable seed bank to a spring pre- scribed fire. One week before and 1 week after a May 2002 prescribed burn, soil samples were taken under P. mono- phylla trees, under Artemisia tridentata ssp. vaseyana shrubs, and from interspace microsites. Two growing seasons after the prescribed burn, soil samples were taken from the same microsites and from similar microsites in an adjacent unburned area. Prior to the burn, the germinable seed bank under shrubs contained the highest seed density and the highest species richness followed by interspace and tree microsites. Shrub litter was consumed by the burn, causing complete loss of the seed bank from that microsite and depleting the A. tridentata seed bank. Interestingly, the density of germinable seeds in soil under P. monophylla trees increased immediately following the burn; 70% of that increase originated from the annual forb Descurainia pinnata. Two growing seasons following the prescribed burn, no overall dif- ferences in germinable seed density between burned and unburned plots were observed, but seed bank species compo- sition differed, with seed banks in the prescribed burn having a greater abundance of Eriogonum elatum, E. microthe- cum, and Gayophytum diffusum compared to unburned plots, which had a greater abundance of A. tridentata, Lappula occidentalis, and Descurainia pinnata. Our results indicate that rapid restoration to prefire vegetation cannot rely upon the soil seed bank. To ensure rapid recovery, land managers should select sites for prescribed burns that have fire-tolerant perennial vegetation.
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Restoring riparian meadows currently dominated by Artemisa using alternative state concepts – above-ground vegetation response
Applied Vegetation Science, 2002Co-Authors: J. Michael Wright, Jeanne C. ChambersAbstract:Abstract Livestock overgrazing and stream incision in the western USA often result in encroachment and dominance of Artemisia tridentata ssp. tridentata (Big sagebrush) in riparian areas that formerly supported meadows. To define the alternative states and thresholds for these ecosystems, we conducted a restoration experiment that included sites with high, intermediate or low water tables. We used a paired-plot approach in which one plot on each site was burned and seeded with native grasses and forbs typical of naturally occurring dry meadow and Artemisia/Leymus cinereus ecological types, while adjacent unburned plots served as controls. Sites with high and intermediate water tables had greater initial abundances of perennial grasses typical of dry meadows, such as Leymus triticoides and Poa secunda ssp. juncifolia, and these species increased after the burn. In contrast, sites with low water tables were dominated by annual forbs such as Chenopodium album and Descurainia pinnata after the burn. Biomass i...
Dae-jin Yun - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana
Journal of Experimental Botany, 2010Co-Authors: Francesco Orsini, Matilde Paino D'urzo, Gunsu Inan, Dong Ha Oh, Federica Consiglio, Michael V Mickelbart, Sara Serra, Jae Cheol Jeong, Xia Li, Dae-jin YunAbstract:Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research.
James R Manhart - One of the best experts on this subject based on the ideXlab platform.
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Descurainia pinnata native 2
2011Co-Authors: James R ManhartAbstract:Descurainia pinnata, whole plant. Family Brassicaceae, Subclass Dilleniidae. Origin: Native.
J. Michael - One of the best experts on this subject based on the ideXlab platform.
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Restoring riparian meadows currently dominated by Artemisa using alternative state concepts - above-ground vegetation response
2020Co-Authors: J. MichaelAbstract:Livestock overgrazing and stream incision in the western USA often result in encroachment and dominance of Artemisia tridentata ssp. tridentata (Big sagebrush) in ripar- ian areas that formerly supported meadows. To define the alternative states and thresholds for these ecosystems, we conducted a restoration experiment that included sites with high, intermediate or low water tables. We used a paired-plot approach in which one plot on each site was burned and seeded with native grasses and forbs typical of naturally occurring dry meadow and Artemisia/Leymus cinereus ecological types, while adjacent unburned plots served as controls. Sites with high and intermediate water tables had greater initial abun- dances of perennial grasses typical of dry meadows, such as Leymus triticoides and Poa secunda ssp. juncifolia, and these species increased after the burn. In contrast, sites with low water tables were dominated by annual forbs such as Chenopo- dium album and Descurainia pinnata after the burn. Biomass increased progressively from 1997 to 1999 on burned plots, while controls showed little change. Burning effects were microsite specific, with former Artemisia microsites exhibit- ing lower biomass than interspaces initially, but similar or higher biomass by the third year. Establishment of seeded species was low and species composition was determined largely by pre-burn vegetation. Artemisia dominated sites with high water tables appear to represent an alternative state of the dry meadow ecological type, while sites with low water table sites have crossed an abiotic threshold governed by water tables and represent a new ecological type. Burning is an effective tool for restoring relatively high water table sites, but low water table sites will require burning and seeding with species adapted to more xeric conditions.
Francesco Orsini - One of the best experts on this subject based on the ideXlab platform.
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A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana
Journal of Experimental Botany, 2010Co-Authors: Francesco Orsini, Matilde Paino D'urzo, Gunsu Inan, Dong Ha Oh, Federica Consiglio, Michael V Mickelbart, Sara Serra, Jae Cheol Jeong, Xia Li, Dae-jin YunAbstract:Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research.