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Sample records for hardwood hybrid poplar

  1. An endemic population of western poplar clearwing moths (Lepidoptera: Sesiidae) invades a monoculture of hybrid poplar.

    PubMed

    Brown, John J; Kittelson, Neal T; Hannon, Eugene R; Walsh, Douglas B

    2006-06-01

    Western poplar clearwing, Paranthrene robiniae (Hy. Edwards) (Lepidoptera: Sesiidae), is endemic in Pacific Northwest riparian habitats at low population densities. These moths have colonized commercial hybrid poplar (Populus spp.) plantings. Moth populations increased rapidly and became a major pest. Trap catches of male moths in mid-season surveys increased 190-fold from 95 in 2001 to >18,500 in 2002 across 6597 ha of poplars monitored. The outbreak of western poplar clearwings was widespread in 2002. Pheromone-baited traps placed one trap per 81.75 ha over 13,274 ha of commercial poplars captured >108,000 male moths in 2002. Damage to commercial poplars included girdling of saplings and burrows in limbs and trunks of trees. Repeated applications of chlorpyrifos failed to reduce the abundance of moths in 2002. Two management strategies over two separate plantations of approximately 6500 ha each were contrasted. Future control strategies recommend a halt to the use of contact insecticides that target adult moths. Short-term (3-5 yr) control should involve a pheromone-based mating disruption strategy followed eventually by selection of a clone that is less susceptible to P. robiniae attack. PMID:16813311

  2. Fitness dynamics within a poplar hybrid zone: I. Prezygotic and postzygotic barriers impacting a native poplar hybrid stand

    PubMed Central

    Roe, Amanda D; MacQuarrie, Chris J K; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-01-01

    Hybridization and introgression are pervasive evolutionary phenomena that provide insight into the selective forces that maintain species boundaries, permit gene flow, and control the direction of evolutionary change. Poplar trees (Populus L.) are well known for their ability to form viable hybrids and maintain their distinct species boundaries despite this interspecific gene flow. We sought to quantify the hybridization dynamics and postzygotic fitness within a hybrid stand of balsam poplar (Populus balsamifera L.), eastern cottonwood (P. deltoides Marsh.), and their natural hybrids to gain insight into the barriers maintaining this stable hybrid zone. We observed asymmetrical hybrid formation with P. deltoides acting as the seed parent, but with subsequent introgression biased toward P. balsamifera. Native hybrids expressed fitness traits intermediate to the parental species and were not universally unfit. That said, native hybrid seedlings were absent from the seedling population, which may indicate additional selective pressures controlling their recruitment. It is imperative that we understand the selective forces maintaining this native hybrid zone in order to quantify the impact of exotic poplar hybrids on this native system. PMID:24967081

  3. Phytoremediation of trichloroethylene with hybrid poplars.

    PubMed

    Gordon, M; Choe, N; Duffy, J; Ekuan, G; Heilman, P; Muiznieks, I; Ruszaj, M; Shurtleff, B B; Strand, S; Wilmoth, J; Newman, L A

    1998-08-01

    Axenic tumor cultures of poplar cells, clone H11-11, were grown in the presence of [14C]-trichloroethylene (TCE) (uniformly labeled). The cells were capable of metabolizing TCE to produce trichloroethanol, di- and trichloroacetic acid. Some of the carbon from TCE was found in insoluble, nonextractable cell residue, and small amounts were mineralized to [14C]CO2. Poplar cuttings grown in soil and exposed to TCE produced the same metabolites. In field trials, trees were planted in soil in test cells and exposed to TCE via underground water injection during the growing season. During the growing season, at least 95% of the TCE was removed from the influent water stream in cells containing trees. Mass balance studies conducted in the laboratory indicated that 70 to 90% of the TCE was transpired; however, greenhouse and field study results showed that less than 5% of the total TCE taken up by the plants is transpired. These results show that significant TCE uptake and degradation occur in poplars. Poplars appear to be useful for in situ remediation of TCE-contaminated sites under proper conditions. PMID:9703485

  4. Fitness dynamics within a poplar hybrid zone: II. Impact of exotic sex on native poplars in an urban jungle

    PubMed Central

    Roe, Amanda D; MacQuarrie, Chris JK; Gros-Louis, Marie-Claude; Simpson, J Dale; Lamarche, Josyanne; Beardmore, Tannis; Thompson, Stacey L; Tanguay, Philippe; Isabel, Nathalie

    2014-01-01

    Trees bearing novel or exotic gene components are poised to contribute to the bioeconomy for a variety of purposes such as bioenergy production, phytoremediation, and carbon sequestration within the forestry sector, but sustainable release of trees with novel traits in large-scale plantations requires the quantification of risks posed to native tree populations. Over the last century, exotic hybrid poplars produced through artificial crosses were planted throughout eastern Canada as ornamentals or windbreaks and these exotics provide a proxy by which to examine the fitness of exotic poplar traits within the natural environment to assess risk of exotic gene escape, establishment, and spread into native gene pools. We assessed postzygotic fitness traits of native and exotic poplars within a naturally regenerated stand in eastern Canada (Quebec City, QC). Pure natives (P. balsamifera and P. deltoides spp. deltoides), native hybrids (P. deltoides × P. balsamifera), and exotic hybrids (trees bearing Populus nigra and P. maximowiczii genetic components) were screened for reproductive biomass, yield, seed germination, and fungal disease susceptibility. Exotic hybrids expressed fitness traits intermediate to pure species and were not significantly different from native hybrids. They formed fully viable seed and backcrossed predominantly with P. balsamifera. These data show that exotic hybrids were not unfit and were capable of establishing and competing within the native stand. Future research will seek to examine the impact of exotic gene regions on associated biotic communities to fully quantify the risk exotic poplars pose to native poplar forests. PMID:24963382

  5. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar

    DOE PAGESBeta

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J.; Fountain, Mackenzie; Ralph, John; Hodge, David B.; Hegg, Eric L.

    2016-02-09

    Background: Strategies to improve copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment of hybrid poplar were investigated. These improvements included a combination of increasing hydrolysis yields, while simultaneously decreasing process inputs through (i) more efficient utilization of H2O2 and (ii) the addition of an alkaline extraction step prior to the metal-catalyzed AHP pretreatment. We hypothesized that utilizing this improved process could substantially lower the chemical inputs needed during pretreatment. Results: Hybrid poplar was pretreated utilizing a modified process in which an alkaline extraction step was incorporated prior to the Cu-AHP treatment step and H2O2 was added batch-wise over the course of 10more » h. Our results revealed that the alkaline pre-extraction step improved both lignin and xylan solubilization, which ultimately led to improved glucose (86 %) and xylose (95 %) yields following enzymatic hydrolysis. An increase in the lignin solubilization was also observed with fed-batch H2O2 addition relative to batch-only addition, which again resulted in increased glucose and xylose yields (77 and 93 % versus 63 and 74 %, respectively). Importantly, combining these strategies led to significantly improved sugar yields (96 % glucose and 94 % xylose) following enzymatic hydrolysis. In addition, we found that we could substantially lower the chemical inputs (enzyme, H2O2, and catalyst), while still maintaining high product yields utilizing the improved Cu-AHP process. This pretreatment also provided a relatively pure lignin stream consisting of ≥90 % Klason lignin and only 3 % xylan and 2 % ash following precipitation. Two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR and size-exclusion chromatography demonstrated that the solubilized lignin was high molecular weight (Mw ≈ 22,000 Da) and only slightly oxidized relative to lignin from untreated poplar. In conclusion: This study demonstrated that the fed

  6. Biodegradation of Trichloroethylene by an Endophyte of Hybrid Poplar

    PubMed Central

    Kang, Jun Won; Khan, Zareen

    2012-01-01

    We isolated and characterized a novel endophyte from hybrid poplar. This unique endophyte, identified as Enterobacter sp. strain PDN3, showed high tolerance to trichloroethylene (TCE). Without the addition of inducers, such as toluene or phenol, PDN3 rapidly reduced TCE levels in medium from 72.4 μM to 30.1 μM in 24 h with a concurrent release of 127 μM chloride ion, and nearly 80% of TCE (55.3 μM) was dechlorinated by PDN3 in 5 days with 166 μM chloride ion production, suggesting TCE degradation. PMID:22367087

  7. Host selection and probing behavior of the poplar aphid Chaitophorus leucomelas (Sternorrhyncha: Aphididae) on two poplar hybrids with contrasting susceptibility to aphids.

    PubMed

    Barrios-San Martín, Joceline; Quiroz, Andrés; Verdugo, Jaime A; Parra, Leonardo; Hormazabal, Emilio; Astudillo, Luis A; Rojas-Herrera, Marcelo; Ramírez, Claudio C

    2014-02-01

    Poplars are frequently attacked by aphids. The differential susceptibility of poplar hybrids to the aphid Chaitophorus leucomelas Koch (Sternorrhyncha: Aphididae) has been described, but the mechanism underlying this pattern is unknown. This work tested the hypothesis that poplar resistance to this aphid is associated with the presence of volatiles and secondary plant compounds that affect host selection and feeding behavior. This hypothesis was tested by studying the host choice and feeding behavior of C. leucomelas on two poplar hybrids with contrasting susceptibilities to this aphid ([Populus trichocarpa Torrey & Gray x Populus deltoides Bartram ex Marshall] x P. deltoides [TD x D], and [P. trichocarpa x Populus maximowiczii Henry] x [P. trichocarpa x P. maximowiczii] [TM x TM]). The results showed that C. leucomelas rejected leaves of the TM x TM hybrid and did not prefer odors from either hybrid. Electronic monitoring of the probing behavior of C. leucomelas suggested the involvement of antifeedant factors in the TM x TM hybrid. In addition, the chemical characterization of volatiles, epicuticular waxes, and internal phenols of leaves from both poplar hybrids revealed that TM x TM had a higher abundance of monoterpenes, sesquiterpenes, n-alkanes, and phenols. These results are discussed in terms of their contribution to poplar breeding programs aimed at enhancing insect resistance. PMID:24665710

  8. Biotechnology and genetic selection of fast-growing hardwoods

    SciTech Connect

    White, E.H.; Abrahamson, L.P.; Maynard, C.A. . Research Foundation)

    1989-07-01

    Hybrid poplar have been shown to be useful for a wide variety of products. Their fast growth and ease in maintaining desirable genetic character make hybrid poplar highly suited to intensive culture systems. This study was initiated to evaluate a genetic selection trail consisting of 54 hybrid poplar clones and to locate and sample eastern cottonwood (Populus deltoides Bartr.) trees for obtainment of scion material to be included in a poplar germplasm archive for future breeding purposes. Because the basis of an effective and cost efficient fast-growing hardwood plantation program is a gene pool with a broad genetic base, the quality and diversity of the genetic resource are of prime concern to the long-term success of biotechnology, agroforestry programs. Additionally, tests of the captured gene pool in site-specific genetic selection and clone-site trials are the necessary successive steps to establish a viable woody crop biomass program. The current project sought to address both of these basic issues so as to improve management opportunities for short-rotation hybrid poplar energy plantations in New York State. Results of the studies showed that short rotation intensive culture hybrid poplar systems are feasible in New York State, and can be successfully used if proper site conditions exist and appropriate establishment and maintenance techniques are used.

  9. Nitrogen fertilizer and sewage sludge effects on hybrid poplars. Final report

    SciTech Connect

    Riha, S.R.; Senesac, G.P.; Naylor, L.

    1985-01-01

    Experiments conducted in the greenhouse compared the growth and nutrient and heavy metal uptake in two clones of hybrid poplar grown in soil amended with nitrogen fertilizer or sewage sludge. In addition, poplar responses to weed competition and to rooting prior to planting were investigated. Both fertilizer and sludge application increased poplar stem biomass. Weeds reduced poplar biomass. The large difference in root biomass of the two poplar clones may account for different effects weed and sludge application had on nutrient and heavy metal uptake in each clone. The relatively small root biomass of I-45/51 increased with increasing sludge application, as did the uptake of nutrients and heavy metals. The relatively large root biomass of clone NE-510 was reduced when weeds were present, as was nutrient and heavy metal uptake. Other results suggest that poplars with low root-to-stem ratios may be most affected by weed competition, especially after their first year, and that nitrogen fertilization may alleviate effects of weeds on their growth. Poplars grown in sludge-amended soil did not accumulate more of any nutrient or heavy metal studied compared to those grown in nitrogen-fertilized soil. 17 refs., 5 figs., 57 tabs.

  10. Polyphenol oxidase from hybrid poplar. Cloning and expression in response to wounding and herbivory.

    PubMed

    Constabel, C P; Yip, L; Patton, J J; Christopher, M E

    2000-09-01

    The inducible expression of polyphenol oxidase (PPO), a presumed antiherbivore enzyme, was examined in hybrid poplar (Populus trichocarpa x Populus deltoides). Following mechanical wounding simulating insect damage, PPO activity increased dramatically in wounded and unwounded leaves on wounded plants beginning at 24 and 48 h, respectively. A hybrid poplar PPO cDNA was isolated and its nucleotide sequence determined. On northern blots, PPO transcripts were detected within 8 h of wounding, and reached peak levels at 16 and 24 h in wounded and unwounded leaves, respectively. Methyl jasmonate spray and feeding by forest tent caterpillar also induced PPO expression. The induction of PPO was strongest in the youngest four leaves, which were generally avoided by caterpillars in free feeding experiments. This wound- and herbivore-induced expression of PPO in hybrid poplar supports the defensive role of this protein against insect pests. PMID:10982443

  11. Transgenic Hybrid Poplar for Sustainable and Scalable Production of the Commodity/Specialty Chemical, 2-Phenylethanol

    PubMed Central

    Costa, Michael A.; Marques, Joaquim V.; Dalisay, Doralyn S.; Herman, Barrington; Bedgar, Diana L.; Davin, Laurence B.; Lewis, Norman G.

    2013-01-01

    Fast growing hybrid poplar offers the means for sustainable production of specialty and commodity chemicals, in addition to rapid biomass production for lignocellulosic deconstruction. Herein we describe transformation of fast-growing transgenic hybrid poplar lines to produce 2-phenylethanol, this being an important fragrance, flavor, aroma, and commodity chemical. It is also readily converted into styrene or ethyl benzene, the latter being an important commodity aviation fuel component. Introducing this biochemical pathway into hybrid poplars marks the beginnings of developing a platform for a sustainable chemical delivery system to afford this and other valuable specialty/commodity chemicals at the scale and cost needed. These modified plant lines mainly sequester 2-phenylethanol via carbohydrate and other covalently linked derivatives, thereby providing an additional advantage of effective storage until needed. The future potential of this technology is discussed. MALDI metabolite tissue imaging also established localization of these metabolites in the leaf vasculature. PMID:24386157

  12. Transgenic hybrid poplar for sustainable and scalable production of the commodity/specialty chemical, 2-phenylethanol.

    PubMed

    Costa, Michael A; Marques, Joaquim V; Dalisay, Doralyn S; Herman, Barrington; Bedgar, Diana L; Davin, Laurence B; Lewis, Norman G

    2013-01-01

    Fast growing hybrid poplar offers the means for sustainable production of specialty and commodity chemicals, in addition to rapid biomass production for lignocellulosic deconstruction. Herein we describe transformation of fast-growing transgenic hybrid poplar lines to produce 2-phenylethanol, this being an important fragrance, flavor, aroma, and commodity chemical. It is also readily converted into styrene or ethyl benzene, the latter being an important commodity aviation fuel component. Introducing this biochemical pathway into hybrid poplars marks the beginnings of developing a platform for a sustainable chemical delivery system to afford this and other valuable specialty/commodity chemicals at the scale and cost needed. These modified plant lines mainly sequester 2-phenylethanol via carbohydrate and other covalently linked derivatives, thereby providing an additional advantage of effective storage until needed. The future potential of this technology is discussed. MALDI metabolite tissue imaging also established localization of these metabolites in the leaf vasculature. PMID:24386157

  13. Post-establishment fertilization of Minnesota hybrid poplar plantations.

    SciTech Connect

    Coleman, M., D.; Tolsted, D.; Nichols, T.; Johnson, W., D.; Ween, E.G.; Houghtaling, T.

    2006-01-01

    Experimental plantings were installed at five sites in three locations in western Minnesota. Aboveground biomass production increased 43-82% as a result of three annual applications of urea or balanced nutrient blend fertilizer beginning near canopy closure. There were no production differences between the type of fertilizer used, indicating that N was the major limiting nutrient. Responses were consistent from site to site, indicating that hybrid poplar stands in this region at this stage of development would be very responsive to fertilization. Leaf tissue N, P, and K concentrations increased in response to both fertilizer treatments; P and K increased more frequently in response to the blend treatment compared to the N-only urea treatment. The diagnosis and recommendation integrated system (DRIS) indices indicated that the stands were near optimal nutritional balance prior to fertilization. Treatments increased individual leaf area and leaf litter production up to 33% and 37%, respectively. Canopy leaf area, leaf N concentration and the sum of DRIS indices were correlated with aboveground production. Growth efficiency, the ratio of production to canopy leaf area, increased with both fertilizer treatment and successive years of treatment, indicating improved stand vigor due to nutrient amendments. Stand production increased more in response to changes in leaf N concentration as stands aged. Plantation production continued to increase with increased internal N concentration even when deficiency levels or levels defined as sufficient for fast growth were exceeded. The correlation between aboveground production and the sum of DRIS indices shows that optimal nutrition at canopy closure may result in current aboveground dry matter production exceeding 13Mgha-1 yr-1. Multiple small-dose amendments appear to be effective in increasing production by maintaining high internal N concentrations.

  14. Thaumatin-like proteins are differentially expressed and localized in phloem tissue of hybrid poplar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two thaumatin-like proteins (TLPs) were previously identified in phloem exudate of hybrid poplar (Populus trichocarpa x P. deltoides) using proteomics methods, and their sieve element localization confirmed by immunofluorescence. In the current study, we analyzed different tissues to further underst...

  15. Gaseous NO2 effects on stomatal behavior, photosynthesis and respiration of hybrid poplar leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (NO2, 4 microliter per liter) on stomatal conductance, photosynthesis, dark- and photorespiration of Populus alba x Populus berolinensis hybrid leaves using the photosynthesis system and scanning...

  16. Large-scale hybrid poplar production economics: 1995 Alexandria, Minnesota establishment cost and management

    SciTech Connect

    Downing, M.; Langseth, D.; Stoffel, R.; Kroll, T.

    1996-12-31

    The purpose of this project was to track and monitor costs of planting, maintaining, and monitoring large scale commercial plantings of hybrid poplar in Minnesota. These costs assists potential growers and purchasers of this resource to determine the ways in which supply and demand may be secured through developing markets.

  17. Isoprene biosynthesis in hybrid poplar impacts ozone tolerance

    NASA Astrophysics Data System (ADS)

    Behnke, K.; Kleist, E.; Uerlings, R.; Wildt, J.; Rennenberg, H.; Schnitzler, J. P.

    2009-04-01

    Isoprene is the most abundant volatile compound emitted by vegetation. It influences air chemistry and is thought to take part in plant defense reactions against abiotic stress such as high temperature or ozone. However, whether or not isoprene emission interacts with ozone tolerance of plants is still in discussion. We exploited transgenic non-isoprene emitting Grey poplar (Populus x canescens) in a biochemical and physiological model study to investigate the effect of acute ozone stress on the elicitation of defense-related emissions of plant volatiles, photosynthesis and the antioxidative system. We recorded that non-isoprene emitting poplars are more resistant to ozone as indicated by less damaged leaf area and higher assimilation rates compared to ozone-exposed wild type plants. The integral of green leaf volatile (GLV) emissions was different between the two poplar phenotypes and a reliable early marker for subsequent leaf damage. For other stress-induced volatiles like mono-, homo-, and sesquiterpenes, and methyl salicylate similar time profiles, pattern and emission intensities were observed in both transgenic and wild type plants. However, un-stressed non-isoprene emitting poplars are characterized by elevated levels of ascorbate and α-tocopherol as well as a more effective de-epoxidation ratio of xanthophylls than in wild type plants. Since ozone quenching properties of ascorbate are much higher than those of isoprene and furthermore α-tocopherol also is an essential antioxidant, non-isoprene emitting poplars might benefit from changes within the antioxidative system by providing them with enhanced ozone tolerance.

  18. Sorption, uptake, and biotransformation of 17β-estradiol, 17α-ethinylestradiol, zeranol, and trenbolone acetate by hybrid poplar.

    PubMed

    Bircher, Sam; Card, Marcella L; Zhai, Guangshu; Chin, Yu-Ping; Schnoor, Jerald L

    2015-12-01

    Hormonally active compounds may move with agricultural runoff from fields with applied manure and biosolids into surface waters where they pose a threat to human and environmental health. Riparian zone plants could remove hormonally active compounds from agricultural runoff. Therefore, sorption to roots, uptake, translocation, and transformation of 3 estrogens (17β-estradiol, 17α-ethinylestradiol, and zeranol) and 1 androgen (trenbolone acetate) commonly found in animal manure or biosolids were assessed by hydroponically grown hybrid poplar, Populus deltoides x nigra, DN-34, widely used in riparian buffer strips. Results clearly showed that these hormones were rapidly removed from 2 mg L(-1) hydroponic solutions by more than 97% after 10 d of exposure to full poplar plants or live excised poplars (cut-stem, no leaves). Removals by sorption to dead poplar roots that had been autoclaved were significantly less, 71% to 84%. Major transformation products (estrone and estriol for estradiol; zearalanone for zeranol; and 17β-trenbolone from trenbolone acetate) were detected in the root tissues of all 3 poplar treatments. Root concentrations of metabolites peaked after 1 d to 5 d and then decreased in full and live excised poplars by further transformation. Metabolite concentrations were less in dead poplar treatments and only slowly increased without further transformation. Taken together, these findings show that poplars may be effective in controlling the movement of hormonally active compounds from agricultural fields and avoiding runoff to streams. PMID:26184466

  19. Cultivation of fast-growing hardwoods

    SciTech Connect

    White, E.H.; Abrahamson, L.P. . Coll. of Environmental Science and Forestry)

    1991-10-01

    The intensive culture of hybrid poplar has received in-depth study as part of the Fast-Growing Hardwood Program. Research has concentrated on short-rotation intensive culture systems. Specific studies and operations included establishing and maintaining a nursery/cutting orchard, installing clone-site trials in central and southern New York State and initiating studies of no-till site preparation, nutrient utilization efficiency, wood quality and soil solution chemistry. The nursery/cutting orchard was used to provide material for various research plantings and as a genotype repository. Clone- site trials results showed that hybrid poplar growth potential was affected by clone type and was related to inherent soil-site conditions. No-till techniques were shown to be successful in establishing hybrid poplar in terms of survival and growth when compared to conventional clean tillage and/or no competition control, and can be considered for use on sites that are particularly prone to erosion. Nutrient use efficiency was significantly affected by clone type, and should be a consideration when selecting clones for operational planting if fertilization is to be effectively and efficiently used. Wood quality differed among clones with site condition and tree age inferred as important factors. Soil solution chemistry was minimally affected by intensive cultural practices with no measured adverse effect on soil water quality. Generally, results of these studies showed that appropriate hybrid poplar clones grown in short-rotation intensively cultured systems can be used successfully in New York State if proper site conditions exist and appropriate establishment and maintenance techniques are used. 37 refs., 4 figs., 22 tabs.

  20. Potential of genetically engineered hybrid poplar for pyrolytic production of bio-based phenolic compounds.

    PubMed

    Toraman, Hilal E; Vanholme, Ruben; Borén, Eleonora; Vanwonterghem, Yumi; Djokic, Marko R; Yildiz, Guray; Ronsse, Frederik; Prins, Wolter; Boerjan, Wout; Van Geem, Kevin M; Marin, Guy B

    2016-05-01

    Wild-type and two genetically engineered hybrid poplar lines were pyrolyzed in a micro-pyrolysis (Py-GC/MS) and a bench scale setup for fast and intermediate pyrolysis studies. Principal component analysis showed that the pyrolysis vapors obtained by micro-pyrolysis from wood of caffeic acid O-methyltransferase (COMT) and caffeoyl-CoA O-methyltransferase (CCoAOMT) down-regulated poplar trees differed significantly from the pyrolysis vapors obtained from non-transgenic control trees. Both fast micro-pyrolysis and intermediate pyrolysis of transgenic hybrid poplars showed that down-regulation of COMT can enhance the relative yield of guaiacyl lignin-derived products, while the relative yield of syringyl lignin-derived products was up to a factor 3 lower. This study indicates that lignin engineering via genetic modifications of genes involved in the phenylpropanoid and monolignol biosynthetic pathways can help to steer the pyrolytic production of guaiacyl and syringyl lignin-derived phenolic compounds such as guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-vinylguaiacol, syringol, 4-vinylsyringol, and syringaldehyde present in the bio-oil. PMID:26890798

  1. Engineering functional artificial hybrid proteins between poplar peroxiredoxin II and glutaredoxin or thioredoxin

    SciTech Connect

    Rouhier, Nicolas . E-mail: nrouhier@scbiol.uhp-nancy.fr; Gama, Filipe; Wingsle, Gunnar; Gelhaye, Eric; Gans, Pierre; Jacquot, Jean-Pierre

    2006-03-24

    The existence of natural peroxiredoxin-glutaredoxin hybrid enzymes in several bacteria is in line with previous findings indicating that poplar peroxiredoxin II can use glutaredoxin as an electron donor. This peroxiredoxin remains however unique since it also uses thioredoxin with a quite good efficiency. Based on the existing fusions, we have created artificial enzymes containing a poplar peroxiredoxin module linked to glutaredoxin or thioredoxin modules. The recombinant fusion enzymes folded properly into non-covalently bound homodimers or homotetramers. Two of the three protein constructs exhibit peroxidase activity, a reaction where the two modules need to function together, but they also display enzymatic activities specific of each module. In addition, mass spectrometry analyses indicate that the Prx module can be both glutathiolated or overoxidized in vitro. This is discussed in the light of the Prx reactivity.

  2. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites. PMID:12710235

  3. Thaumatin-like proteins are differentially expressed and localized in phloem tissues of hybrid poplar

    PubMed Central

    2010-01-01

    Background Two thaumatin-like proteins (TLPs) were previously identified in phloem exudate of hybrid poplar (Populus trichocarpa × P. deltoides) using proteomics methods, and their sieve element localization confirmed by immunofluorescence. In the current study, we analyzed different tissues to further understand TLP expression and localization in poplar, and used immunogold labelling to determine intracellular localization. Results Immunofluorescence using a TLP antiserum confirmed the presence of TLP in punctate, organelle-like structures within sieve elements. On western blots, the antiserum labeled two constitutively expressed proteins with distinct expression patterns. Immunogold labelling suggested that TLPs are associated with starch granules and starch-containing plastids in sieve elements and phloem parenchyma cells. In addition, the antiserum recognized TLPs in the inner cell wall and sieve plate region of sieve elements. Conclusions TLP localization in poplar cells and tissues is complex. TLP1 is expressed predominantly in tissues with a prominent vascular system such as midveins, petioles and stems, whereas the second TLP is primarily expressed in starch-storing plastids found in young leaves and the shoot apex. PMID:20796310

  4. Influence of soil fertility and water stress on the ozone response of hybrid poplar trees

    SciTech Connect

    Harkov, R.; Brennan, E.

    1980-01-01

    Experiments were conducted to determine the role of soil fertility and water stress on the ozone response of hybrid poplar trees. Rooted cuttings of hybrid poplar clone number388 (Populus maximowiczii X P. trichocarpa) were grown in a filtered-air greenhouse in 4.73-L plastic pots containing a greenhouse potting mix. A slow release 18-6-12 NPK fertilizer was added to obtain four soil fertility levels. Although the nitrogen content of the foliage increased significantly, after 2 months of growth, neither linear growth nor percent dry weight was affected by these amendments. Trees with a foliar content of approximately 2.69% N were found to be more susceptible to ozone fumigation of 196 ..mu..g/m/sup 3/ for 6 hr than were trees with 1.53, 3.12, or 3.47% N. In the water stress experiment, withholding water from the test plants for 6-9 days reduced the relative water content in the foliage to 7-21%, respectively, below that of control plants, and protected the trees from a 6-hr fumigation at 196 ..mu..g/m/sup 3/. Visible water stress symptoms were not evident in plants from which water had been withheld for 6 days. These results are discussed as they pertain to susceptibility of urban trees to ozone damage.

  5. Predicting yields of short-rotation hybrid poplar (Populus spp.) for the United States through model-data synthesis.

    PubMed

    Wang, Dan; LeBauer, David; Dietze, Michael

    2013-06-01

    Hybrid poplar (Populus spp.) is an important biomass crop being evaluated for cellulosic ethanol production. Predictions of poplar growth, rotation period, and soil carbon sequestration under various growing conditions, soils, and climates are critical for farmers and managers planning to establish short-rotation forestry (SRF) plantations. In this study, we used an ecoinformatics workflow, the Predictive Ecosystem Analyzer (PEcAn), to integrate literature data and field measurements into the Ecosystem Demography 2 (ED2) model to estimate yield potential of poplar plantations. Within PEcAn 164 records of seven different traits from the literature were assimilated using a Bayesian meta-analysis. Next, variance decomposition identified seven variables for further constraint that contributed > 80% to the uncertainty in modeled yields: growth respiration, dark respiration, quantum efficiency, mortality coefficient, water conductance, fine-root allocation, and root turnover rate. Assimilation of observed yields further constrained uncertainty in model parameters (especially dark respiration and root turnover rate) and biomass estimates. Additional measurements of growth respiration, mortality, water conductance, and quantum efficiency would provide the most efficient path toward further constraint of modeled yields. Modeled validation demonstrated that ED2 successfully captured the interannual and spatial variability of poplar yield observed at nine independent sites. Site-level analyses were conducted to estimate the effect of land use change to SRF poplar on soil C sequestration compared to alternate land uses. These suggest that poplar plantations became a C sink within 18 years of conversion from corn production or existing forest. Finally, poplar yields were estimated for the contiguous United States at a half degree resolution in order to determine potential productivity, estimate the optimal rotation period, and compare poplar to perennial grass yields. This

  6. Bt-Cry3Aa expression reduces insect damage and improves growth in field-grown hybrid poplar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa gene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa x P. deltoides, clones 24-305, 50-197, and 198-434; and P. d...

  7. Hybrid poplar and forest soil response to municipal and industrial by-products: a greenhouse study.

    PubMed

    Cavaleri, Molly A; Gilmore, Daniel W; Mozaffari, Morteza; Rosen, Carl J; Halbach, Thomas R

    2004-01-01

    Little research has been conducted in the Lake States (Minnesota, Wisconsin, and Michigan) to evaluate the effects of municipal and industrial by-product applications on the early growth of short rotation woody crops such as hybrid poplar. Anticipated shortages of harvestable-age aspen in the next decade can be alleviated and rural development can be enhanced through the application of by-products to forest soils. This study was conducted to evaluate the effects of inorganic fertilizer, boiler ash, biosolids, and the co-application of ash and biosolids application on tree growth and soil properties by measuring hybrid poplar clone NM-6 (Populus nigra L. x P. maximowiczii A. Henry) yield, nutrient uptake, and select post-harvest soil properties after 15 wk of greenhouse growth. Treatments included a control of no amendment; agricultural lime; inorganic N, P, and K; three types of boiler ash; biosolids application rates equivalent to 70, 140, 210, and 280 kg available N ha(-1); and boiler ash co-applied with biosolids. All of the by-products treatments showed biomass production that was equal to or greater than inorganic fertilizer and lime treatments. A trend of increased biomass with increasing rates of biosolids was observed. Soil P concentration increased with increasing rates of biosolids application. None of the by-products treatments resulted in plant tissue metal concentrations greater than metal concentrations of plant tissue amended with inorganic amendments. Biosolids, boiler ash, and the co-application of biosolids and boiler ash together on forest soils were as beneficial to plant growth as inorganic fertilizers. PMID:15224944

  8. Prioritization of copper for the use in photosynthetic electron transport in developing leaves of hybrid poplar

    PubMed Central

    Shahbaz, Muhammad; Ravet, Karl; Peers, Graham; Pilon, Marinus

    2015-01-01

    Plastocyanin (PC) is an essential and abundant copper (Cu) protein required for photosynthesis in higher plants. Severe copper deprivation has the potential to cause a defect in photosynthetic electron transport due to a lack in PC. The Cu-microRNAs, which are up-regulated under Cu deficiency, down-regulate the expression of target Cu proteins other than PC, cytochrome-c oxidase and the ethylene receptors. It has been proposed that this mechanism saves Cu for PC maturation. We aimed to test how hybrid poplar, a species that has capacity to rapidly expand its photosynthetically active tissue, responds to variations in Cu availability over time. Measurement of chlorophyll fluorescence after Cu depletion revealed a drastic effect on photosynthesis in hybrid poplar. The decrease in photosynthetic capacity was correlated with a reduction in PC protein levels. Compared to older leaves, PC decreased more strongly in developing leaves, which also lost more photosynthetic electron transport capacity. The effect of Cu depletion on older and more developed leaves was minor and these leaves maintained much of their photosynthetic capacity. Interestingly, upon resupply of Cu to the medium a very rapid recovery of Cu levels was seen in the younger leaves with a concomitant rise in the expression and activity of PC. In contrast, the expression of those Cu proteins, which are targets of microRNAs was under the same circumstances delayed. At the same time, Cu resupply had only minor effects on the older leaves. The data suggest a model where rapid recovery of photosynthetic capacity in younger leaves is made possible by a preferred allocation of Cu to PC in younger leaves, which is supported by Cu-microRNA expression. PMID:26089828

  9. Effect of site on growth of hybrid poplar clones planted on a commercial scale

    SciTech Connect

    Woods, R.F.

    1985-01-01

    Two-, four-, and five-year height growth of Populus hybrids were measured over a full range of USDA Soil Conservation Service natural and altered soil drainage and texture classes on fields planted by Packaging Corporation of America using intensive culture. Five clonal trials with 40 clones each were examined for 4-year height growth and were analyzed for effects of site, clone and site by clone interaction. Substantial soil variability became an important factor on the previously-planted sites and had to be considered in the statistical analysis. Ten clones with the best 4-year height growth were identified. Four- and five-year height growth of several of the most promising clones from the clonal trials were then examined over a range of soil/site conditions in commercial-size plantations using a tillage plus herbicide management system. Two-year growth was evaluated using a no-till system. Height growth under both management systems significantly decreased on sites other than those with the most optimum conditions for agricultural crops. Using the results from the clonal trials and the two tillage system studies, soil/site factors which affected establishment and early growth of hybrid popular plantings were summarized and outlined in detail, and a practical field guide was formulated for evaluating the potential of agricultural fields for the intensive culture of hybrid poplars.

  10. Investigating the drought-stress response of hybrid poplar genotypes by metabolite profiling.

    PubMed

    Barchet, Genoa L H; Dauwe, Rebecca; Guy, Robert D; Schroeder, William R; Soolanayakanahally, Raju Y; Campbell, Malcolm M; Mansfield, Shawn D

    2014-11-01

    Drought stress is perhaps the most commonly encountered abiotic stress plants experience in the natural environment, and it is one of the most important factors limiting plant productivity. Here, we employed untargeted metabolite profiling to examine four drought-stressed hybrid poplar (Populus spp.) genotypes for their metabolite content, using gas chromatography coupled to mass spectrometry. The primary objective of these analyses was to characterize the metabolite profile of poplar trees to assess relative drought resistance and to investigate the underlying biochemical mechanisms employed by the genotypes to combat drought. Metabolite profiling identified key metabolites that increased or decreased in relative abundance upon exposure to drought stress. Overall, amino acids, the antioxidant phenolic compounds catechin and kaempferol, as well as the osmolytes raffinose and galactinol exhibited increased abundance under drought stress, whereas metabolites involved in photorespiration, redox regulation and carbon fixation showed decreased abundance under drought stress. One clone in particular, Okanese, displayed unique responses to the imposed drought conditions. This clone was found to have higher leaf water potential, but lower growth rate relative to the other clones tested. Okanese also had lower accumulation of osmolytes such as raffinose, galactinol and proline, but higher overall levels of antioxidants such as catechin and dehydroascorbic acid. As such, it was proposed that osmotic adjustment as a mechanism for drought avoidance in this clone is not as well developed in comparison with the other clones investigated in this study, and that a possible alternative mechanism for the enhanced drought avoidance displayed by Okanese may be due to differential allocation of resources or better retention of water. PMID:24178982

  11. Development and Validation of Marker-Aided Selection Methods for Wood Property Traits in Loblolly Pine and Hybrid Poplar

    SciTech Connect

    Tuskan, G.A.

    2001-06-20

    Wood properties influence pulp and paper quality. Certainly, overall pulp yields are directly related to the cellulose content, changes in hemicellulose content are associated with changes in pulp cohesiveness, and pulping efficiency is related to lignin content. Despite the importance of wood properties on product quality, little progress has been made in improving such traits because current methods of assessing wood and fiber characteristics are time-consuming, expensive, and often imprecise. Genetic improvement of wood and fiber properties has been further hampered by the large size of trees, delayed reproductive maturity and long harvest cycles. Recent developments in molecular genetics will help overcome the physical, economic and biological constraints in assessing and improving wood properties. Genetic maps consisting of numerous molecular markers are now available for loblolly pine and hybrid poplar. Such markers/maps may be used as part of a marker-aided selection and breeding effort or to expedite the isolation and characterization of genes and/or promoters that directly control wood properties. The objectives of this project are: (1) to apply new and rapid analytical techniques for assessing component wood properties to segregating F2 progeny populations of loblolly pine and hybrid poplar, (2) to map quantitative trait loci and identify molecular markers associated with wood properties in each of the above species and (3) to validate marker-aided selection methods for wood properties in loblolly pine and hybrid poplar.

  12. Factors Influencing the Tissue Culture and the Agrobacterium tumefaciens-Mediated Transformation of Hybrid Aspen and Poplar Clones

    PubMed Central

    De Block, Marc

    1990-01-01

    Tissue culture conditions and transformation have been established for both aspen and poplar. The use of previously described culture conditions resulted in shoot tip necrosis in the shoot cultures and necrosis of stem and leaf explants. Shoot tip necrosis could be overcome by buffering the medium with 2-(N-morpholino)ethanesulfonic acid and Ca-gluconate and by growing the shoots below 25°C. Necrosis of the explants was probably due to an accumulation of ammonium in the explants and could be overcome by adapting the NO3−/NH4+ ratio of the media. Stem explants of established shoot cultures of the aspen hybrid Populus alba × P. tremula and of the poplar hybrid Populus trichocarpa × P. deltoides were cocultivated with Agrobacterium strains having chimeric bar and neo genes on their disarmed tDNAs. Transformed aspen shoots were obtained from 30 to 40% of the explants, while transformed poplar shoots were obtained from 10% of the explants. Extracts from the transformed trees contained high phosphinotricin acetyltransferase and neomycin phosphotransferase activities, and the trees contained one to three copies of the chimeric genes. The transformed trees were completely resistant to the commercial preparations of the herbicide phosphinotricin (glufosinate), while control trees were not. Images Figure 1 Figure 2 Figure 4 PMID:16667565

  13. A National Assessment of Promising Areas for Switchgrass, Hybrid Poplar, or Willow Energy Crop Production

    SciTech Connect

    Graham, R.L.; Walsh, M.E.

    1999-02-01

    The objective of this paper is to systematically assess the cropland acreage that could support energy crops and the expected farm gate and delivered prices of energy crops. The assessment is based on output from two modeling approaches: (1) the Oak Ridge County-Level Energy Crop (ORECCL) database (1996 version) and (2) the Oak Ridge Integrated Bioenergy Analysis System (ORIBAS). The former provides county-level estimates of suitable acres, yields, and farmgate prices of energy crops (switchgrass, hybrid poplar, willow) for all fifty states. The latter estimates delivered feedstock prices and quantities within a state at a fine resolution (1 km2) and considers the interplay between transportation costs, farmgate prices, cropland density, and facility demand. It can be used to look at any type of feedstock given the appropriate input parameters. For the purposes of this assessment, ORIBAS has been used to estimate farmgate and delivered switchgrass prices in 11 states (AL, FL, GA, IA, M N, MO, ND, NE, SC, SD, and TN). Because the potential for energy crop production can be considered from several perspectives, and is evolving as policies, economics and our basic understanding of energy crop yields and production costs change, this assessment should be viewed as a snapshot in time.

  14. Ozone Sensitivity in Hybrid Poplar Is Correlated with a Lack of Defense-Gene Activation1

    PubMed Central

    Riehl Koch, Jennifer; Scherzer, Amy J.; Eshita, Steven M.; Davis, Keith R.

    1998-01-01

    Ozone is a major gaseous pollutant thought to contribute to forest decline. Although the physiological and morphological responses of forest trees to ozone have been well characterized, little is known about the molecular basis for these responses. Our studies compared the response to ozone of ozone-sensitive and ozone-tolerant clones of hybrid poplar (Populus maximowizii × Populus trichocarpa) at the physiological and molecular levels. Gas-exchange analyses demonstrated clear differences between the ozone-sensitive clone 388 and the ozone-tolerant clone 245. Although ozone induced a decrease in photosynthetic rate and stomatal conductance in both clones, the magnitude of the decrease in stomatal conductance was significantly greater in the ozone-tolerant clone. RNA-blot analysis established that ozone-induced mRNA levels for phenylalanine ammonia-lyase, O-methyltransferase, a pathogenesis-related protein, and a wound-inducible gene were significantly higher in the ozone-tolerant than in the ozone-sensitive plants. Wound- and pathogen-induced levels of these mRNAs were also higher in the ozone-tolerant compared with the ozone-sensitive plants. The different physiological and molecular responses to ozone exposure exhibited by clones 245 and 388 suggest that ozone tolerance involves the activation of salicylic-acid- and jasmonic-acid-mediated signaling pathways, which may be important in triggering defense responses against oxidative stress. PMID:9847098

  15. Post-treatment mechanical refining as a method to improve overall sugar recovery of steam pretreated hybrid poplar.

    PubMed

    Dou, Chang; Ewanick, Shannon; Bura, Renata; Gustafson, Rick

    2016-05-01

    This study investigates the effect of mechanical refining to improve the sugar yield from biomass processed under a wide range of steam pretreatment conditions. Hybrid poplar chips were steam pretreated using six different conditions with or without SO2. The resulting water insoluble fractions were subjected to mechanical refining. After refining, poplar pretreated at 205°C for 10min without SO2 obtained a 32% improvement in enzymatic hydrolysis and achieved similar overall monomeric sugar recovery (539kg/tonne) to samples pretreated with SO2. Refining did not improve hydrolyzability of samples pretreated at more severe conditions, nor did it improve the overall sugar recovery. By maximizing overall sugar recovery, refining could partially decouple the pretreatment from other unit operations, and enable the use of low temperature, non-sulfur pretreatment conditions. The study demonstrates the possibility of using post-treatment refining to accommodate potential pretreatment process upsets without sacrificing sugar yields. PMID:26881333

  16. Boron accumulation and tolerance of hybrid poplars grown on a B-laden mixed paper mill waste landfill.

    PubMed

    Rees, Rainer; Robinson, Brett H; Rog, Christopher J; Papritz, Andreas; Schulin, Rainer

    2013-03-01

    Paper mill wastes are a mixture of by-products from pulp production and on-site energy production, consisting of paper mill sludge, ash and cinders. Landfilling of these highly boron (B) and heavy metal laden waste products carries environmental risks. Poplars have been successfully employed in the phytomanagement and hydraulic control of B contaminated sites. Here, we assess the performance of hybrid poplars on a paper-mill waste landfill, investigate the accumulation of B by the trees and explore the relationship between local-scale root growth and substrate properties. Leaf and root tissue samples were collected on three plots and analyzed for their chemical properties and root traits. Additionally, we sampled four soil cores in the vicinity of each of the trees and determined chemical and physical properties. Using a principal component analysis followed by a cluster analysis, we identified three substrate types. This method delineated the soil effects on tree survival and growth, although correlations with individual soil element concentrations were weak. Despite signs of B toxicity in some leaves, B was not the key limiting factor for poplar growth. Instead, Ca deficiency caused by a Mg:Ca imbalance was the primary reason for the poor performance of some trees. Root growth was not limited by toxicity effects of soil contaminants. Our results show that hybrid poplars perform well under the harsh growing conditions on a multi-contaminated, B-laden substrate in a hemiboreal climate. Exploiting the differences in the performance of the four clones in relation to the soil types, could increase the success of revegetation on this and other landfills. PMID:22727995

  17. Secondary successional trajectories of structural and catabolic bacterial communities in oil-polluted soil planted with hybrid poplar.

    PubMed

    Mukherjee, Shinjini; Sipilä, Timo; Pulkkinen, Pertti; Yrjälä, Kim

    2015-02-01

    Poplars have widely been used for rhizoremediation of a broad range of organic contaminants for the past two decades. Still, there is a knowledge gap regarding the rhizosphere-associated bacterial communities of poplars and their dynamics during the remediation process. It is envisaged that a detailed understanding of rhizosphere-associated microbial populations will greatly contribute to a better design and implementation of rhizoremediation. To investigate the long-term succession of structural and catabolic bacterial communities in oil-polluted soil planted with hybrid poplar, we carried out a 2-year field study. Hybrid aspen (Populus tremula × Populus tremuloides) seedlings were planted in polluted soil excavated from an accidental oil-spill site. Vegetated and un-vegetated soil samples were collected for microbial community analyses at seven different time points during the course of 2 years and sampling time points were chosen to cover the seasonal variation in the boreal climate zone. Bacterial community structure was accessed by means of 16S rRNA gene amplicon pyrosequencing, whereas catabolic diversity was monitored by pyrosequencing of alkane hydroxylase and extradiol dioxygenase genes. We observed a clear succession of bacterial communities on both structural and functional levels from early to late-phase communities. Sphingomonas type extradiol dioxygenases and alkane hydroxylase homologs of Rhodococcus clearly dominated the early-phase communities. The high-dominance/low-diversity functional gene communities underwent a transition to low-dominance/high-diversity communities in the late phase. These results pointed towards increased catabolic capacities and a change from specialist to generalist strategy of bacterial communities during the course of secondary succession. PMID:25545194

  18. Spatial variability of soil carbon and nitrogen in two hybrid poplar-hay crop systems in southern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Winans, K. S.

    2013-12-01

    Canadian agricultural operations contribute approximately 8% of national GHG emissions each year, mainly from fertilizers, enteric fermentation, and manure management (Environment Canada, 2010). With improved management of cropland and forests, it is possible to mitigate GHG emissions through carbon (C) sequestration while enhancing soil and crop productivity. Tree-based intercropped (TBI) systems, consisting of a fast-growing woody species such as poplar (Populus spp.) planted in widely-spaced rows with crops cultivated between tree rows, were one of the technologies prioritized for investigation by the Agreement for the Agricultural Greenhouse Gases Program (AAGGP), because fast growing trees can be a sink for atmospheric carbon-dioxide (CO2) as well as a long-term source of farm income (Montagnini and Nair, 2004). However, there are relatively few estimates of the C sequestration in the trees or due to tree inputs (e.g., fine root turnover, litterfall that gets incorporated into SOC), and hybrid poplars grow exponentially in the first 8-10 years after planting. With the current study, our objectives were (1) to evaluate spatial variation in soil C and nitrogen (N) storage, CO2 and nitrogen oxide (N20), and tree and crop productivity for two hybrid poplar-hay intercrop systems at year 9, comparing TBI vs. non-TBI systems, and (2) to evaluate TBI systems in the current context of C trading markets, which value C sequestration in trees, unharvested crop components, and soils of TBI systems. The study results will provide meaningful measures that indicate changes due to TBI systems in the short-term and in the long-term, in terms of GHG mitigation, enhanced soil and crop productivity, as well as the expected economic returns in TBI systems.

  19. Effect of hybrid poplar trees on microbial populations important to hazardous waste bioremediation

    SciTech Connect

    Jordahl, J.L.; Foster, L.; Schnoor, J.L.; Alvarez, P.J.J.

    1997-06-01

    Microbial concentrations of denitrifiers, pseudomonads, and monoaromatic petroleum hydrocarbon (BTX) degraders were significantly higher (p < 0.1) in soil samples from the rhizosphere of poplar trees than in adjacent agricultural soils, and atrazine degraders were found only in one rhizosphere sample. The relative abundance of these phenotypes (as a fraction of total heterotrophs) was not significantly different between rhizosphere and surrounding soils. Therefore, the poplar rhizosphere enhanced the growth of microbial populations that participate in natural bioremediation without exerting selective pressure for them.

  20. Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis

    PubMed Central

    2010-01-01

    Background Thaxtomin A (TA), a phytotoxin produced by the phytopathogen Streptomyces scabies, is essential for the development of potato common scab disease. TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides) cell suspensions can activate a cellular program leading to cell death. In contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. The purpose of this study is to characterize TA-habituated cells and the mechanisms that may be involved in enhancing resistance to TA. Results Habituation to TA was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than three years. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition, with a reduction in cellulose and an increase in pectin levels. Remarkably, high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover, these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis, dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using an Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications. Conclusions We have shown that habituation to TA induced durable resistance to the bacterial toxin in poplar cells. TA-habituation also enhanced resistance to two other structurally different inhibitors of cellulose

  1. Reduced expression of the SHORT-ROOT gene increases the rates of growth and development in hybrid poplar and Arabidopsis.

    PubMed

    Wang, Jiehua; Andersson-Gunnerås, Sara; Gaboreanu, Ioana; Hertzberg, Magnus; Tucker, Matthew R; Zheng, Bo; Leśniewska, Joanna; Mellerowicz, Ewa J; Laux, Thomas; Sandberg, Göran; Jones, Brian

    2011-01-01

    SHORT-ROOT (SHR) is a well characterized regulator of cell division and cell fate determination in the Arabidopsis primary root. However, much less is known about the functions of SHR in the aerial parts of the plant. In this work, we cloned SHR gene from Populus trichocarpa (PtSHR1) as an AtSHR ortholog and down-regulated its expression in hybrid poplar (Populus tremula×P. tremuloides Michx-clone T89) in order to determine its physiological functions in shoot development. Sharing a 90% similarity to AtSHR at amino acid level, PtSHR1 was able to complement the Arabidopsis shr mutant. Down regulation of PtSHR1 led to a strong enhancement of primary (height) and secondary (girth) growth rates in the transgenic poplars. A similar approach in Arabidopsis showed a comparable accelerated growth and development phenotype. Our results suggest that the response to SHR could be dose-dependent and that a partial down-regulation of SHR could lead to enhanced meristem activity and a coordinated acceleration of plant growth in woody species. Therefore, SHR functions in plant growth and development as a regulator of cell division and meristem activity not only in the roots but also in the shoots. Reducing SHR expression in transgenic poplar was shown to lead to significant increases in primary and secondary growth rates. Given the current interest in bioenergy crops, SHR has a broader role as a key regulator of whole plant growth and development and SHR suppression has considerable potential for accelerating biomass accumulation in a variety of species. PMID:22194939

  2. Cellulose and lignin biosynthesis is altered by ozone in wood of hybrid poplar (Populus tremula×alba)

    PubMed Central

    Richet, Nicolas; Afif, Dany; Huber, Françoise; Pollet, Brigitte; Banvoy, Jacques; El Zein, Rana; Lapierre, Catherine; Dizengremel, Pierre; Perré, Patrick; Cabané, Mireille

    2011-01-01

    Wood formation in trees is a dynamic process that is strongly affected by environmental factors. However, the impact of ozone on wood is poorly documented. The objective of this study was to assess the effects of ozone on wood formation by focusing on the two major wood components, cellulose and lignin, and analysing any anatomical modifications. Young hybrid poplars (Populus tremula×alba) were cultivated under different ozone concentrations (50, 100, 200, and 300 nl l−1). As upright poplars usually develop tension wood in a non-set pattern, the trees were bent in order to induce tension wood formation on the upper side of the stem and normal or opposite wood on the lower side. Biosynthesis of cellulose and lignin (enzymes and RNA levels), together with cambial growth, decreased in response to ozone exposure. The cellulose to lignin ratio was reduced, suggesting that cellulose biosynthesis was more affected than that of lignin. Tension wood was generally more altered than opposite wood, especially at the anatomical level. Tension wood may be more susceptible to reduced carbon allocation to the stems under ozone exposure. These results suggested a coordinated regulation of cellulose and lignin deposition to sustain mechanical strength under ozone. The modifications of the cellulose to lignin ratio and wood anatomy could allow the tree to maintain radial growth while minimizing carbon cost. PMID:21357770

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

    PubMed

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

    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) identify promising genotypes for potential use in future systems. We evaluated height, diameter, and volume after first year budset by testing 20 poplar clones and two willow clones. Unrooted cuttings, 20 cm long, were planted in randomized complete blocks at 0.91- x 0.91-m spacing at Gary, IN, USA (41.5 degrees N, 87.3 degrees W). Four commercial poplar clones (NM6, DN5, DN34, and DN182) were planted as 20- and 60-cm cuttings. Sixty-cm cuttings exhibited greater height and diameter than 20-cm cuttings; however, we recommend continued use and testing of different combinations of genotype and cutting length. We identified promising genotypes for potential use in future systems and we recommend allocating the majority of resources into commercial poplar clones, given their generalist growth performance. However, further utilization and selection of experimental clones is needed. Specific clones rather than genomic groups should be selected based on the geographic location and soil conditions of the site. PMID:16285410

  4. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress.

    PubMed

    Hennig, Anne; Kleinschmit, Jörg R G; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites. PMID:26042130

  5. Water consumption and biomass production of protoplast fusion lines of poplar hybrids under drought stress

    PubMed Central

    Hennig, Anne; Kleinschmit, Jörg R. G.; Schoneberg, Sebastian; Löffler, Sonja; Janßen, Alwin; Polle, Andrea

    2015-01-01

    Woody crops such as poplars (Populus) can contribute to meet the increasing energy demand of a growing human population and can therefore enhance the security of energy supply. Using energy from biomass increases ecological sustainability as biomass is considered to play a pivotal role in abating climate change. Because areas for establishing poplar plantations are often confined to marginal sites drought tolerance is one important trait for poplar genotypes cultivated in short rotation coppice. We tested 9-month-old plants of four tetraploid Populus tremula (L.) × P. tremuloides (Michx.) lines that were generated by protoplast fusion and their diploid counterpart for water consumption and drought stress responses in a greenhouse experiment. The fusion lines showed equivalent or decreased height growth, stem biomass and total leaf area compared to the diploid line. The relative height increment of the fusion lines was not reduced compared to the diploid line when the plants were exposed to drought. The fusion lines were distinguished from the diploid counterpart by stomatal characteristics such as increased size and lower density. The changes in the stomatal apparatus did not affect the stomatal conductance. When exposed to drought the carbohydrate concentrations increased more strongly in the fusion lines than in the diploid line. Two fusion lines consumed significantly less water with regard to height growth, producing equivalent or increased relative stem biomass under drought compared to their diploid relative. Therefore, these tetraploid fusion lines are interesting candidates for short rotation biomass plantation on dry sites. PMID:26042130

  6. Molecular cloning, expression analysis and subcellular localization of four DELLA genes from hybrid poplar.

    PubMed

    Liu, Sian; Xuan, Lei; Xu, Li-An; Huang, Minren; Xu, Meng

    2016-01-01

    Gibberellic acid (GA) signaling regulates diverse aspects of plant growth and developmental processes. The DELLA repressors of GA signaling are named for an N-terminal conserved DELLA domain. In this study, four genes encoding DELLA proteins, PeRGA1, PeRGA2, PeGAI1 and PeGAI2, were isolated and characterized in poplar. A gene structural analysis revealed that the DELLA genes were all intron-free. Multiple protein sequence alignments revealed that these proteins contained seven highly conserved domains: the DELLA domain, the TVHYNP domain, leucine heptad repeat I (LHR I), the VHIID domain, leucine heptad repeat II (LHR II), the PFYRE domain, and the SAM domain. Temporal expression patterns of these genes were profiled during the adventitious root development of poplar. The four DELLA genes were expressed in root, stem and leaf in a dynamic manner. The subcellular localization demonstrated that these DELLA genes were mainly localized to the nucleus. These results suggest that the four DELLA genes may play diverse regulatory roles in the adventitious root, stem and leaf development of poplar, and contribute to improving our understanding of conserved and divergent aspects of DELLA proteins that restrain GA signaling in various species. PMID:27478746

  7. Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana).

    PubMed

    Rees, Rainer; Robinson, Brett H; Menon, Manoj; Lehmann, Eberhard; Günthardt-Goerg, Madeleine S; Schulin, Rainer

    2011-12-15

    Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations <900 mg kg(-1) only <10% of the poplar leaf area showed signs of toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue. PMID:22050628

  8. Geographic Information System (GIS) evaluation of dedicated hybrid poplar fuel supply for a 50 MW electricity plant

    SciTech Connect

    Withrow, K.D.; Wichert, D.

    1996-12-31

    An energy geographic information system (GIS) was created for Wisconsin and used to evaluate a proposed 50 MW biomass fueled electricity plant. The GIS analysis supported a project proposal submitted to DOE`s Biomass for Rural Development solicitation. In steady-state operation, the proposed plant would burn 50% dedicated short-rotation woody crops (SRWC) and 50% crop residues. A model of promising agricultural land for growing hybrid poplar trees was created. Marginal agricultural land was sought to minimize competition with traditional crops. Two types of promising land were identified based on different marginality criteria. Approximately 356,850 acres of promising land within 50 miles of the plant site were identified based on characteristics of the land (slope, water table depth, bedrock depth and flooding potential). An additional 489,990 acres of promising land were identified based on soil fertility, for which an index incorporating cation exchange capacity and water holding capacity was created. Approximately 3.8 percent of this promising land would have to be converted to hybrid poplar production to meet the entire dedicated biomass input to the electricity plant assuming a yield of 5 tons/acre/year in steady state. Suitability of infrastructure and other features (electric lines, electric service territories, roads, railroads, land cover) to support a new biomass plant in the Plover area were also evaluated using the Wisconsin energy GIS. The methodology is presented as a model to be applied for other biomass and renewable energy plants. Development of an energy GIS and use of ARC/Info software was found to be a useful tool for biomass analysis, although some limitations were created by the structure and accuracy of the data sets, especially STATSGO. Further research and data development would increase the reliability of estimates produced using GIS technology and applying a similar methodology.

  9. Tree and stand water fluxes of hybrid poplar clone (Populus nigra x P. maximowiczii) in short rotation coppice culture

    NASA Astrophysics Data System (ADS)

    Fischer, M.; Trnka, M.; Kucera, J.; Zalud, Z.

    2010-09-01

    This study reports on evapotranspiration and tree water use in short rotation coppice culture of hybrid poplar (Populus nigra x P. maximowiczii) for biomass energy in the Czech Republic. The high density poplar plantation (10 000 trees per ha) was established in 2003 on arable land in Czech-Moravian Highland (49°32´ N, 16°15´ E, 530 m a.s.l.) and has been coppiced in rotation period of 7 years. Firstly, evapotranspiration of the stand has been estimated by applying the Bowen ratio-energy budget method, which is considered as reliable, robust, quite simple and inexpensive technique with comparable results to eddy covariance and lysimeters. The gaps in evapotranspiration diurnal patterns caused by limitation of the bowen ratio method were filled with simple linear regression model based on relation between potential and actual evapotranspiration with regard to soil water availability and leaf area index and thus the daily, monthly and seasonal totals could be calculated. The amount of evapotranspiration during the growing season 2009 (1 March - 31 October) was 593 mm with highest monthly total 116 mm in June. Mean daily water loss over the season reached 2.43 mm per day. During the hot summer day, the maximal value 5.73 mm per day, which presented 89 % of potential evapotranspiration calculated by Penman equation, was recorded with a peak rate 0.94 mm per hour. Secondly, the transpiration was measured by sap flow tissue heat balance techniques on four individual trees with greatest stem diameters (11 - 12 cm d.b.h.) and height of 12 - 12.5 m. Relatively high transpiration values by the poplars were found during the measured part of growing season (18 June - 31 October), with maximum and mean daily transpiration of 44.41 dm3 and 16.69 dm3 per day, respectively. The seasonal transpiration of the most vigorous from the investigated individuals amounted 2542 dm3. Because in this study we didńt evaluate the transpiration of thinner trees (technical features of sap

  10. Phasing Variants in Poplar Trees using a Hybrid of Short & Long Read Technologies

    SciTech Connect

    Schackwitz, Wendy; Martin, Joel; Lipzen, Anna; Pennacchio, Len; Tuskan, Gerald

    2013-03-26

    Poplar grow throughout the West coast & are adapted to extremely variable conditions. To examine what allows for this wide range of growth conditions, Jerry Tuskan's team has collected 1000 different individuals from British Columbia to California. In 2009, three Common Gardens were established where each individual was cloned in triplicate. Nearly all of these trees have been sequenced using short read technology, revealing a huge degree of variation in genotype. Correlating this genomic variation to phenotype would be greatly be strengthened if the variants could be phased into long haplotype blocks.

  11. Green revolution trees: semidwarfism transgenes modify gibberellins, promote root growth, enhance morphological diversity, and reduce competitiveness in hybrid poplar.

    PubMed

    Elias, Ani A; Busov, Victor B; Kosola, Kevin R; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W; Rood, Stewart B; Strauss, Steven H

    2012-10-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA(20) and GA(8), in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations. PMID:22904164

  12. Biomass carbon, nitrogen and phosphorus stocks in hybrid poplar buffers, herbaceous buffers and natural woodlots in the riparian zone on agricultural land.

    PubMed

    Fortier, Julien; Truax, Benoit; Gagnon, Daniel; Lambert, France

    2015-05-01

    In many temperate agricultural areas, riparian forests have been converted to cultivated land, and only narrow strips of herbaceous vegetation now buffer many farm streams. The afforestation of these riparian zones has the potential to increase carbon (C) storage in agricultural landscapes by creating a new biomass sink for atmospheric CO2. Occurring at the same time, the storage of nitrogen (N) and phosphorus (P) in plant biomass, is an important water quality function that may greatly vary with types of riparian vegetation. The objectives of this study were (1) to compare C, N and P storage in aboveground, belowground and detrital biomass for three types of riparian vegetation cover (9-year-old hybrid poplar buffers, herbaceous buffers and natural woodlots) across four agricultural sites and (2) to determine potential vegetation cover effects on soil nutrient supply rate in the riparian zone. Site level comparisons suggest that 9-year-old poplar buffers have stored 9-31 times more biomass C, 4-10 times more biomass N, and 3-7 times more biomass P than adjacent non managed herbaceous buffers, with the largest differences observed on the more fertile sites. The conversion of these herbaceous buffers to poplar buffers could respectively increase C, N and P storage in biomass by 3.2-11.9 t/ha/yr, 32-124 kg/ha/yr and 3.2-15.6 kg/ha/yr, over 9 years. Soil NO3 and P supply rates during the summer were respectively 57% and 66% lower in poplar buffers than in adjacent herbaceous buffers, potentially reflecting differences in nutrient storage and cycling between the two buffer types. Biomass C ranged 49-160 t/ha in woodlots, 33-110 t/ha in poplar buffers and 3-4 t/ha in herbaceous buffers. Similar biomass C stocks were found in the most productive poplar buffer and three of the four woodlots studied. Given their large and varied biomass C stocks, conservation of older riparian woodlots is equally important for C balance management in farmland. In addition, the

  13. Physiology and Thermal Imaging of Poplar Hybrids with Varying Temperature Tolerance

    NASA Astrophysics Data System (ADS)

    Ibsen, P.; Van Leeuwen, W. J. D.; McCorkel, J.; Barron-Gafford, G.; Moore, D. J.

    2014-12-01

    : Plants growing in high temperatures may suffer from reduced photosynthetic efficiency, increased water demand and thermal damage to tissue. Leaves may mitigate heat stress through physiological or physical strategies which include minimizing heat load, maximizing evaporative cooling or biochemical stabilization. In this study, leaf temperature of wild-type and genetically modified (GM) poplar trees was monitored using a thermal infrared camera and fine wire thermocouples. The GM trees did not have the capacity to produce the compound isoprene, hypothesized to biochemically protect plants against heat stress. One genotype had GM process applied, but retained isoprene making capacity (empty-vector). Temperature of ambient air and of an artificial leaf of similar size/color were also monitored. Photosynthesis and transpiration were measured using an infra-red gas analyzer. Leaf reflectance in an integrating sphere was determined using a spectrometer. Leaf temperature was maintained close to or below air temperature and was always lower than the fake (non-transpiring leaf). Different genetic lines maintained different leaf temperatures, especially during peak temperature in the mid afternoon. The variance in leaf temperature is explored in relation to its effects on transpiration, photosynthesis and growth across isoprene and non-isoprene emitting trees.

  14. Transcriptome profiles of hybrid poplar (Populus trichocarpa × deltoides) reveal rapid changes in undamaged, systemic sink leaves after simulated feeding by forest tent caterpillar (Malacosoma disstria).

    PubMed

    Philippe, Ryan N; Ralph, Steven G; Mansfield, Shawn D; Bohlmann, Jörg

    2010-11-01

    Poplar has been established as a model tree system for genomic research of the response to biotic stresses. This study describes a series of induced transcriptome changes and the associated physiological characterization of local and systemic responses in hybrid poplar (Populus trichocarpa × deltoides) after simulated herbivory. • Responses were measured in local source (LSo), systemic source (SSo), and systemic sink (SSi) leaves following application of forest tent caterpillar (Malacosoma disstria) oral secretions to mechanically wounded leaves. • Transcriptome analyses identified spatially and temporally dynamic, distinct patterns of local and systemic gene expression in LSo, SSo and SSi leaves. Galactinol synthase was strongly and rapidly upregulated in SSi leaves. Genome analyses and full-length cDNA cloning established an inventory of poplar galactinol synthases. Induced changes of galactinol and raffinose oligosaccharides were detected by anion-exchange high-pressure liquid chromatography. • The LSo leaves showed a rapid and strong transcriptome response compared with a weaker and slower response in adjacent SSo leaves. Surprisingly, the transcriptome response in distant, juvenile SSi leaves was faster and stronger than that observed in SSo leaves. Systemic transcriptome changes of SSi leaves have signatures of rapid change of metabolism and signaling, followed by later induction of defense genes. PMID:20955416

  15. Predicting the effect of deep-rooted hybrid poplars on the groundwater flow system at a large-scale phytoremediation site.

    SciTech Connect

    Quinn, J. J.; Negri, M. C.; Hinchman, R. R.; Moos, L. P.; Wozniak, J. B.; Gatliff, E. G.; Applied Natural Sciences, Inc.

    2001-03-01

    Estimating the effect of phreatophytes on the groundwater flow field is critical in the design or evaluation of a phytoremediation system. Complex hydrogeological conditions and the transient water use rates of trees require the application of numerical modeling to address such issues as hydraulic containment, seasonality, and system design. In 1999, 809 hybrid poplars and willows were planted to phytoremediate the 317 and 319 Areas of Argonne National Laboratory near Chicago, Illinois. Contaminants of concern are volatile organic compounds and tritium. The site hydrogeology is a complex framework of glacial tills interlaced with sands, gravels, and silts of varying character, thickness, and lateral extent. A total of 420 poplars were installed using a technology to direct the roots through a 25-ft (8-m)-thick till to a contaminated aquifer. Numerical modeling was used to simulate the effect of the deep-rooted poplars on this aquifer of concern. Initially, the best estimates of input parameters and boundary conditions were determined to provide a suitable match to historical transient ground-water flow conditions. The model was applied to calculate the future effect of the developing deep-rooted poplars over a 6 year period. The first 3 years represent the development period of the trees. In the fourth year, canopy closure is expected to occur; modeling continues through the first 3 years of the mature plantation. Monthly estimates of water use by the trees are incorporated. The modeling suggested that the mature trees in the plantation design will provide a large degree of containment of groundwater from the upgradient source areas, despite the seasonal nature of the trees' water consumption. The results indicate the likely areas where seasonal dewatering of the aquifer may limit the availability of water for the trees. The modeling also provided estimates of the residence time of groundwater in the geochemically altered rhizosphere of the plantation.

  16. Plantation Forestry under Global Warming: Hybrid Poplars with Improved Thermotolerance Provide New Insights on the in Vivo Function of Small Heat Shock Protein Chaperones1[C][W

    PubMed Central

    Merino, Irene; Contreras, Angela; Jing, Zhong-Ping; Gallardo, Fernando; Cánovas, Francisco M.; Gómez, Luis

    2014-01-01

    Climate-driven heat stress is a key factor affecting forest plantation yields. While its effects are expected to worsen during this century, breeding more tolerant genotypes has proven elusive. We report here a substantial and durable increase in the thermotolerance of hybrid poplar (Populus tremula × Populus alba) through overexpression of a major small heat shock protein (sHSP) with convenient features. Experimental evidence was obtained linking protective effects in the transgenic events with the unique chaperone activity of sHSPs. In addition, significant positive correlations were observed between phenotype strength and heterologous sHSP accumulation. The remarkable baseline levels of transgene product (up to 1.8% of total leaf protein) have not been reported in analogous studies with herbaceous species. As judged by protein analyses, such an accumulation is not matched either by endogenous sHSPs in both heat-stressed poplar plants and field-grown adult trees. Quantitative real time-polymerase chain reaction analyses supported these observations and allowed us to identify the poplar members most responsive to heat stress. Interestingly, sHSP overaccumulation was not associated with pleiotropic effects that might decrease yields. The poplar lines developed here also outperformed controls under in vitro and ex vitro culture conditions (callus biomass, shoot production, and ex vitro survival), even in the absence of thermal stress. These results reinforce the feasibility of improving valuable genotypes for plantation forestry, a field where in vitro recalcitrance, long breeding cycles, and other practical factors constrain conventional genetic approaches. They also provide new insights into the biological functions of the least understood family of heat shock protein chaperones. PMID:24306533

  17. Threshold response of mesophyll CO2 conductance to leaf hydraulics in highly transpiring hybrid poplar clones exposed to soil drying

    PubMed Central

    Pepin, Steeve

    2014-01-01

    Mesophyll conductance (g m) has been shown to impose significant limitations to net CO2 assimilation (A) in various species during water stress. Net CO2 assimilation is also limited by stomatal conductance to water (g sw), both having been shown to co-vary with leaf hydraulic conductance (K leaf). Lately, several studies have suggested a close functional link between K leaf, g sw, and g m. However, such relationships could only be circumstantial since a recent study has shown that the response of g m to drought could merely be an artefactual consequence of a reduced intercellular CO2 mole fraction (C i). Experiments were conducted on 8-week-old hybrid poplar cuttings to determine the relationship between K leaf, g sw, and g m in clones of contrasting drought tolerance. It was hypothesized that changes in g sw and K leaf in response to drought would not impact on g m over most of its range. The results show that K leaf decreased in concert with g sw as drought proceeded, whereas g m measured at a normalized C i remained relatively constant up to a g sw threshold of ~0.15mol m–2 s–1. This delayed g m response prevented a substantial decline in A at the early stage of the drought, thereby enhancing water use efficiency. Reducing the stomatal limitation of droughted plants by diminishing the ambient CO2 concentration of the air did not modify g m or K leaf. The relationship between gas exchange and leaf hydraulics was similar in both drought-tolerant and drought-sensitive clones despite their contrasting vulnerability to stem cavitation and stomatal response to soil drying. The results support the hypothesis of a partial hydraulic isolation of the mesophyll from the main transpiration pathway. PMID:24368507

  18. Continuous steam hydrolysis of tulip poplar

    SciTech Connect

    Fieber, C.; Colcord, A.R.; Faass, S.; Muzzy, J.D.; Roberts, R.S.

    1982-08-01

    To produce ethanol from hardwood it is desirable to fractionate the hardwood in order to produce a relatively pure cellulosic pulp for dilute acid hydrolysis. An experimental investigation of continuous steam hydrolysis of tulip poplar wood chips indicates that over 90% of the lignin present can be extracted by 0.1N sodium hydroxide, resulting in a cellulose pulp containing over 90% hexosan. The study was performed using a Stake Technology, Ltd., continuous digester rated at one oven dry ton per hour of wood chips. The yields of hexosans, hexoses, xylan, xylose, lignin, furfural, acetic acid and methanol were determined as a function of residence time and steam pressure in the digester. The information provides a basis for establishing a material and energy balance for a hardwood to ethanol plant.

  19. Enhanced expression of glutamine synthetase (GS1a) confers altered fibre and wood chemistry in field grown hybrid poplar (Populus tremula X alba) (717-1B4).

    PubMed

    Coleman, Heather D; Cánovas, Francisco M; Man, Huimin; Kirby, Edward G; Mansfield, Shawn D

    2012-09-01

    Hybrid poplar (Populus tremula X P. alba) genetically engineered to express the pine cytosolic glutamine synthetase gene (GS1a) has been previously shown to display desirable field performance characteristics, including enhancements in growth and nitrogen use efficiency. Analysis of wood samples from a 3-year-old field trial of three independently transformed GS1a transgenic hybrid poplar lines revealed that, when compared with wild-type controls, ectopic expression of GS1a resulted in alterations in wood properties and wood chemistry. Included were significant enhancements in wood fibre length, wood density, microfibre angle, per cent syringyl lignin and elevated concentrations of wood sugars, specifically glucose, galactose, mannose and xylose. Total extractive content and acid-insoluble lignin were significantly reduced in wood of GS1a transgenics when compared with wild-type trees. Together, these cell wall characteristics resulted in improved wood pulping attributes, including improved lignin solubilization with no concurrent decrease in yield. Trees with increased GS1a expression have improved characteristics for pulp and paper production and hold potential as a feedstock for biofuels production. PMID:22672155

  20. Green Revolution Trees: Semidwarfism Transgenes Modify Gibberellins, Promote Root Growth, Enhance Morphological Diversity, and Reduce Competitiveness in Hybrid Poplar1[C][W][OA

    PubMed Central

    Elias, Ani A.; Busov, Victor B.; Kosola, Kevin R.; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W.; Rood, Stewart B.; Strauss, Steven H.

    2012-01-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA20 and GA8, in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations. PMID:22904164

  1. Inoculation of hybrid poplar with the endophytic bacterium Enterobacter sp. 638 increases biomass but does not impact leaf level physiology

    SciTech Connect

    Rogers, A.; McDonald, K.; Muehlbauer, M. F.; Hoffman, A.; Koenig, K.; Newman, L.; Taghavi, S.; Van Der Lelie, D.

    2011-01-01

    Endophytic bacteria have been shown to provide several advantages to their host, including enhanced growth. Inoculating biofuel species with endophytic bacteria is therefore an attractive option to increase the productivity of biofuel feedstocks. Here, we investigated the effect of inoculating hard wood cuttings of Populus deltoides Bartr. x Populus. nigra L. clone OP367 with Enterobacter sp. 638. After 17 weeks, plants inoculated with Enterobacter sp. 638 had 55% greater total biomass than un-inoculated control plants. Study of gas exchange and fluorescence in developing and mature leaves over a diurnal cycle and over a 5 week measurement campaign revealed no effects of inoculation on photosynthesis, stomatal conductance, photosynthetic water use efficiency or the maximum and operating efficiency of photosystem II. However, plants inoculated with Enterobacter sp. 638 had a canopy that was 39% larger than control plants indicating that the enhanced growth was fueled by increased leaf area, not by improved physiology. Leaf nitrogen content was determined at two stages over the 5 week measurement period. No effect of Enterobacter sp. 638 on leaf nitrogen content was found indicating that the larger plants were acquiring sufficient nitrogen. Enterobacter sp. 638 lacks the genes for N{sub 2} fixation, therefore the increased availability of nitrogen likely resulted from enhanced nitrogen acquisition by the 84% larger root system. These data show that Enterobacter sp. 638 has the potential to dramatically increase productivity in poplar. If fully realized in the production environment, these results indicate that an increase in the environmental and economic viability of poplar as a biofuel feedstock is possible when inoculated with endophytic bacteria like Enterobacter sp. 638.

  2. Genetic Modification of Short Rotation Poplar Biomass Feedstock for Efficient Conversion to Ethanol

    SciTech Connect

    Dinus, R.J.

    2000-08-30

    The Bioenergy Feedstock Development Program, Environmental Sciences Division, Oak Ridge National Laboratory is developing poplars (Populus species and hybrids) as sources of renewable energy, i.e., ethanol. Notable increases in adaptability, volume productivity, and pest/stress resistance have been achieved via classical selection and breeding and intensified cultural practices. Significant advances have also been made in the efficiencies of harvesting and handling systems. Given these and anticipated accomplishments, program leaders are considering shifting some attention to genetically modifying feedstock physical and chemical properties, so as to improve the efficiency with which feedstocks can be converted to ethanol. This report provides an in-depth review and synthesis of opportunities for and feasibilities of genetically modifying feedstock qualities via classical selection and breeding, marker-aided selection and breeding, and genetic transformation. Information was collected by analysis of the literature, with emphasis on that published since 1995, and interviews with prominent scientists, breeders, and growers. Poplar research is well advanced, and literature is abundant. The report therefore primarily reflects advances in poplars, but data from other species, particularly other shortrotation hardwoods, are incorporated to fill gaps. An executive summary and recommendations for research, development, and technology transfer are provided immediately after the table of contents. The first major section of the report describes processes most likely to be used for conversion of poplar biomass to ethanol, the various physical and chemical properties of poplar feedstocks, and how such properties are expected to affect process efficiency. The need is stressed for improved understanding of the impact of change on both overall process and individual process step efficiencies. The second part documents advances in trait measurement instrumentation and methodology

  3. Vegetation classification in southern pine mixed hardwood forests using airborne scanning laser point data.

    SciTech Connect

    McGaughey, Robert J.; Reutebuch, Stephen E.

    2012-09-01

    Forests of the southeastern United States are dominated by a relatively small number of conifer species. However, many of these forests also have a hardwood component composed of a wide variety of species that are found in all canopy positions. The presence or absence of hardwood species and their position in the canopy often dictates management activities such as thinning or prescribed burning. In addition, the characteristics of the under- and mid-story layers, often dominated by hardwood species, are key factors when assessing suitable habitat for threatened and endangered species such as the Red Cockaded Woodpecker (Picoides borealis) (RCW), making information describing the hardwood component important to forest managers. General classification of cover types using LIDAR data has been reported (Song et al. 2002, Brennan and Webster 2006) but most efforts focusing on the identification of individual species or species groups rely on some type of imagery to provide more complete spectral information for the study area. Brandtberg (2007) found that use of intensity data significantly improved LIDAR detection and classification of three leaf-off deciduous eastern species: oaks (Quercus spp.), red maple (Acer rubrum L.), and yellow poplar (Liriodendron tulipifera L.). Our primary objective was to determine the proportion of hardwood species present in the canopy using only the LIDAR point data and derived products. However, the presence of several hardwood species that retain their foliage through the winter months complicated our analyses. We present two classification approaches. The first identifies areas containing hardwood and softwood (conifer) species (H/S) and the second identifies vegetation with foliage absent or present (FA/FP) at the time of the LIDAR data acquisition. The classification results were used to develop predictor variables for forest inventory models. The ability to incorporate the proportion of hardwood and softwood was important to the

  4. Effects of in vitro ozone treatment on proteolysis of purified rubisco from two hybrid poplar clones. [Populus maximowizii x trichocarpa

    SciTech Connect

    Landry, L.G.; Pell, E.J. )

    1989-04-01

    Plants exposed to ozone (O{sub 3}) exhibited symptoms of premature senescence, including early decline in quantity of rubisco. O{sub 3}-induced oxidation may cause changes in protein conformation of rubisco, resulting in enhanced proteolysis. To test this hypothesis, rubisco was purified from two hybrid clones of Populus maximowizii x trichocarpa, clones 388 and 245, and treated in vitro with O{sub 3} or air. Rubisco was then challenged with bromelain, papain, chymotrypsin, carboxypeptidase A, or endoproteinase Glu-C and percent degradation measured by SDS-PAGE and densitometric scanning of the gels. Degree of rubisco sensitivity to oxidation may be related to available sulfhydryl (SH) groups on the protein. The number of SH groups in native and denatured rubisco was measured for purified rubisco of both clones by DTNB titration method. The relationship between sensitivity to proteolysis and number and availability of SH groups is discussed.

  5. Developing xylem-preferential expression of PdGA20ox1, a gibberellin 20-oxidase 1 from Pinus densiflora, improves woody biomass production in a hybrid poplar.

    PubMed

    Jeon, Hyung-Woo; Cho, Jin-Seong; Park, Eung-Jun; Han, Kyung-Hwan; Choi, Young-Im; Ko, Jae-Heung

    2016-04-01

    Woody biomass has gained popularity as an environmentally friendly, renewable and sustainable resource for liquid fuel production. Here, we demonstrate biotechnological improvement of the quantity and quality of woody biomass by employing developing xylem (DX)-preferential production of gibberellin (GA), a phytohormone that positively regulates stem growth. First, for the proof of concept experiment, we produced transgenic Arabidopsis plants expressing GA20-oxidase, a key enzyme in the production of bioactive GAs, from Pinus densiflora (PdGA20ox1) under the control of either a constitutive 35S promoter, designated 35S::PdGA20ox1, or a DX-specific promoter (originated from poplar), designated DX15::PdGA20ox1. As we hypothesized, both transgenic Arabidopsis plants (35S::PdGA20ox1 and DX15::PdGA20ox1) exhibited an accelerated stem growth that resulted in a large increase of biomass, up to 300% compared to wild-type control plants, together with increased secondary wall thickening and elongation of fibre cells. Next, we applied our concept to the production of transgenic poplar trees. Both transgenic poplar trees (35S::PdGA20ox1 and DX15::PdGA20ox1) showed dramatic increases in biomass, up to 300%, with accelerated stem growth and xylem differentiation. Cell wall monosaccharide composition analysis revealed that in both Arabidopsis and poplar, glucose and xylose contents were significantly increased. However, undesirable phenotypes of 35S::PdGA20ox1 poplar, including poor root growth and leaf development, were found. Interestingly, DX15::PdGA20ox1 poplar resulted in a reduction of undesirable phenotypes. Our results indicate that the controlled production of GAs through a tissue-specific promoter can be utilized as an efficient biotechnological tool for producing enhanced plant biomass, minimizing unwanted effects. PMID:26503830

  6. Gaseous NO2 effects on epidermis and stomata related physiochemical characteristics of hybrid poplar leaves: chemical elements composition, stomatal functions, photosynthesis and respiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mechanisms controlling effects of gaseous nitrogen dioxide on epidermis and stomata dynamics, and photosynthesis and respirations processes are still not fully understood. In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (4 microliters per lite...

  7. Overexpression of gibberellin 20-oxidase1 from Pinus densiflora results in enhanced wood formation with gelatinous fiber development in a transgenic hybrid poplar.

    PubMed

    Park, Eung-Jun; Kim, Hyun-Tae; Choi, Young-Im; Lee, Chanhui; Nguyen, Van Phap; Jeon, Hyung-Woo; Cho, Jin-Seong; Funada, Ryo; Pharis, Richard P; Kurepin, Leonid V; Ko, Jae-Heung

    2015-11-01

    Gibberellins (GAs) are important regulators of plant shoot biomass growth, and GA 20-oxidase (GA20ox) is one of the major regulatory enzymes in the GA biosynthetic pathway. Previously, we showed that the expression levels of a putative GA20ox1 (i.e., PdGA20ox1) in stem tissue of 3-month-old seedlings of 12 families of Pinus densiflora were positively correlated with stem diameter growth across those same families growing in an even-aged 32-year-old pine forest (Park EJ, Lee WY, Kurepin LV, Zhang R, Janzen L, Pharis RP (2015) Plant hormone-assisted early family selection in Pinus densiflora via a retrospective approach. Tree Physiol 35:86-94). To further investigate the molecular function of this gene in the stem wood growth of forest trees, we produced transgenic poplar lines expressing PdGA20ox1 under the control of the 35S promoter (designated as 35S::PdGA20ox1). By age 3 months, most of the 35S::PdGA20ox1 poplar trees were showing an exceptional enhancement of stem wood growth, i.e., up to fourfold increases in stem dry weight, compared with the nontransformed control poplar plants. Significant increases in endogenous GA1, its immediate precursor (GA20) and its catabolite (GA8) in elongating internode tissue accompanied the increased stem growth in the transgenic lines. Additionally, the development of gelatinous fibers occurred in vertically grown stems of the 35S::PdGA20ox1 poplars. An analysis of the cell wall monosaccharide composition of the 35S::PdGA20ox1 poplars showed significant increases in xylose and glucose contents, indicating a qualitative increase in secondary wall depositions. Microarray analyses led us to find a total of 276 probe sets that were upregulated (using threefold as a threshold) in the stem tissues of 35S::PdGA20ox1 poplars relative to the controls. 'Cell organization or biogenesis'- and 'cell wall'-related genes were overrepresented, including many of genes that are involved in cell wall modification. Several transcriptional

  8. Microwave Moisture Measurement System for Hardwood Lumber Drying

    SciTech Connect

    Moschler, William W; Hanson, Gregory R

    2008-09-01

    The goal of this project was to develop a prototype microwave-based moisture sensor system suitable for the kiln drying of hardwood lumber. The moisture sensors developed are battery powered and are capable of communicating with a host kiln control system via spread spectrum wireless communications. We have developed two designs of the sensors working at 4.5 to 6 GHz with linear response to moisture content (MC) over a range of 6-100%. These sensors allow us to make a swept frequency microwave transmission measurement through a small area of a board. Using the prototype electronics and sensors, we have obtained measurements of MC over the above MC range for red oak and yellow poplar with standard deviations of less than 1.5% MC. We have developed data for board thickness corrections and for temperature corrections for the MC measurement system.

  9. Contrasting colonization and plant growth promoting capacity between wild type and gfp-derative of the endophyte Pseudomonas putida W619 in hybrid poplar

    SciTech Connect

    Weyens N.; van der Lelie D.; Boulet, J.; Adriaensen, D.; Timmermans, J.-P.; Prinsen, E.; Van Oevelen, S.; D"Haen, J.; Smeets, K.; Taghavi, S.; Vangronsveld, J.

    2011-06-09

    This study aims to investigate the colonization of poplar by the endophyte Pseudomonas putida W619 and its capacity to promote plant growth. Poplar cuttings were inoculated with P. putida W619 (wild-type or gfp-labelled). The colonization of both strains was investigated and morphological, physiological and biochemical parameters were analyzed to evaluate plant growth promotion. Inoculation with P. putida W619 (wild-type) resulted in remarkable growth promotion, decreased activities of antioxidative defence related enzymes, and reduced stomatal resistance, all indicative of improved plant health and growth in comparison with the non-inoculated cuttings. In contrast, inoculation with gfp-labelled P. putida W619 did not promote growth; it even had a negative effect on plant health and growth. Furthermore, compared to the wildtype strain, colonization by the gfp-labelled P. putida W619::gfp1 was much lower; it only colonized the rhizosphere and root cortex while the wild-type strain also colonized the root xylem vessels. Despite the strong plant growth promoting capacity of P. putida W619 (wild-type), after gfp labelling its growth promoting characteristics disappeared and its colonization capacity was strongly influenced; for these reasons gfp labelling should be applied with sufficient caution.

  10. 78 FR 67979 - Hardwood Lumber and Hardwood Plywood Promotion, Research and Information Order; Referendum...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ...) Hardwood lumber means timber from the wood of a cypress tree or a deciduous, broad-leafed tree (including... into boards or blocks by a sawmill in the United States. (f) Hardwood plywood means a panel...

  11. Assessments of the efficacy of a long-term application of a phytoremediation system using hybrid poplar trees at former oil tank farm sites.

    PubMed

    El-Gendy, Ahmed S; Svingos, Sotero; Brice, Donald; Garretson, Joel H; Schnoor, Jerald

    2009-05-01

    A poplar tree-phytoremediation system was installed at former refinery and tank farm sites in Cabin Creek, West Virginia, to cleanup petroleum-contaminated-soils and groundwater. Groundwater and soils in both sites were sampled and analyzed on a regular basis to monitor changes in contaminant concentration since 1999. The concentration of benzene, toluene, ethylbenzene, xylene, and gasoline range organics (GRO) decreased an average of 81%, 90%, 67%, 78%, and 82%, respectively, in the lower soil horizons and 34%, 84%, 12%, 19%, and 59%, respectively, in groundwater. In addition, concentrations of oxygen, methane, and carbon dioxide in soil gas demonstrated that tree roots dewatered soils and allowed penetration of oxygen deep into the soil profile, creating necessary conditions for rhizosphere bioremediation. Although required clean-up time can limit phytoremediation, it has proven to be a cost-effective strategy for site improvement if imminent pathways for human exposure and risk are not an issue. PMID:19472940

  12. Influence of over-expression of the Flowering Promoting Factor 1 gene (FPF1) from Arabidopsis on wood formation in hybrid poplar (Populus tremula L. × P. tremuloides Michx.).

    PubMed

    Hoenicka, Hans; Lautner, Silke; Klingberg, Andreas; Koch, Gerald; El-Sherif, Fadia; Lehnhardt, Denise; Zhang, Bo; Burgert, Ingo; Odermatt, Jürgen; Melzer, Siegbert; Fromm, Jörg; Fladung, Matthias

    2012-02-01

    Constitutive expression of the FPF1 gene in hybrid aspen (Populus tremula L. × P. tremuloides Michx.) showed a strong effect on wood formation but no effect on flowering time. Gene expression studies showed that activity of flowering time genes PtFT1, PtCO2, and PtFUL was not increased in FPF1 transgenic plants. However, the SOC1/TM3 class gene PTM5, which has been related to wood formation and flowering time, showed a strong activity in stems of all transgenic lines studied. Wood density was lower in transgenic plants, despite significantly reduced vessel frequency which was overcompensated by thinner fibre cell walls. Chemical screening of the wood by pyrolysis GC/MS showed that FPF1 transgenics have higher fractions of cellulose and glucomannan products as well as lower lignin content. The latter observation was confirmed by UV microspectrophotometry on a cellular level. Topochemical lignin distribution revealed a slower increase of lignin incorporation in the developing xylem of the transgenics when compared with the wild-type plants. In line with the reduced wood density, micromechanical wood properties such as stiffness and ultimate stress were also significantly reduced in all transgenic lines. Thus, we provide evidence that FPF1 class genes may play a regulatory role in both wood formation and flowering in poplar. PMID:21909761

  13. Thermal Insulation from Hardwood Residues

    NASA Astrophysics Data System (ADS)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  14. Occurrence and severity of foliar ozone symptoms on sensitive hardwood species in Shenandoah National Park, VA

    SciTech Connect

    Hildebrand, E.; Skelly, J.M. )

    1993-02-01

    To assess the extent of foliar symptoms due to ozone on sensitive hardwoods in the Shenandoah National Park in Virginia, three species were sampled and evaluated at sites of differing elevations adjacent to 3 ozone monitors in 1991 and 1992: black cherry, yellow poplar, and white ash. All foliar samples were evaluated to precent of symptomatic leaves on each branch and average precent leaf area affected. The Horsfall-Barratt rating scale was used to estimate the precent leaf area symptomatic. Ozone symptoms were manifested as stipple on the adazial leaf surface. In the preliminary 1991 sampling, 40, 87, and 7% of black cherry trees sampled were found to be symptomatic at the 3 sites; 63 and 67% of yellow poplar trees sampled were found to be symptomatic at sites 1 and 3, as were 43 and 63% of the white ash at sites 1 and 2 (3 complete sets were not found in 1991). In 1992, the sampling and rating of injury were repeated. Symptoms of ozone injury appeared on 23, 88, and 10% of black cherry, on 17, 7, and 80% of yellow poplar, and 27, 40, and 40% of white ash. Elevation and ozone exposure will be discussed.

  15. Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

    SciTech Connect

    van der Lelie, D.; Taghavi, S.; McCorkle, S. M.; Li, L. L.; Malfatti, S. A.; Monteleone, D.; Donohoe, B. S.; Ding, S. Y.; Adney, W. S.; Himmel, M. E.; Tringe, S. G.

    2012-05-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic 'secretomes' that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to

  16. A Guide to Bottomland Hardwood Restoration

    USGS Publications Warehouse

    Allen, J.A.; Keeland, B.D.; Stanturf, J.A.; Clewell, A.F.; Kennedy, H.E., Jr.

    2001-01-01

    During the last century, a large amount of the original bottomland hardwood forest area in the United States has been lost, with losses greatest in the Lower Mississippi Alluvial Valley and East Texas. With a holistic approach in mind, this manual describes methods to restore bottomland hardwoods in the lower Midwest, including the Lower Mississippi Alluvial Valley and the southeastern United States. Bottomland hardwoods in this guide include not only the hardwood species that predominate in most forested floodplains of the area but also the softwood species such as baldcypress that often co-occur. General restoration planning considerations are discussed as well as more specific elements of bottomland hardwood restoration such as species selection, site preparation, direct seeding, planting of seedlings, and alternative options for revegetation. We recognize that most projects will probably fall more within the realm of reforestation or afforestation rather than a restoration, as some site preparation and the planting of seeds or trees may be the only actions taken. Practical information needed to restore an area is provided in the guide, and it is left up to the restorationist to decide how complete the restoration will be. Postplanting and monitoring considerations are also addressed. Restoration and management of existing forests are included because of the extensive areas of degraded natural forests in need of rehabilitation.

  17. REMOVAL OF SELECTED POLLUTANTS FROM AQUEOUS MEDIA BY HARDWOOD MULCH

    EPA Science Inventory

    Generic hardwood mulch, usually used for landscaping, was utilized to remove several selected pollutants (heavy metals and toxic organic compounds) typically found in urban stormwater (SW) runoff. The hardwood mulch sorbed all the selected pollutants from a spiked stormwater mix...

  18. 77 FR 71017 - Hardwood Plywood From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ... notice in the Federal Register of October 3, 2012 (77 FR 60460). The conference was held in Washington... COMMISSION Hardwood Plywood From China Determinations On the basis of the record \\1\\ developed in the subject... plywood from China that are allegedly subsidized and sold in the United States at less than fair...

  19. Hardwood amended substrates for annual plant production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shortages of peat for use in the greenhouse industry are already a problem, and greenhouse producers are faced with continued shortages, as well as increases in its price. In this study, three hardwood alternatives (sweetgum, hickory or eastern redcedar) were evaluated as amendments to a standard p...

  20. MANUAL FOR ASSESSMENT OF BOTTOMLAND HARDWOOD FUNCTIONS

    EPA Science Inventory

    This manual outlines a procedure for qualitatively assessing the functions and values of bottomland hardwoods (BLH). he procedure is based on the Wetland Evaluation Technique (WET) and for this reason is referred to as WET-BLH. etland functions are the physical, chemical, and bio...

  1. Mercury uptake into poplar leaves.

    PubMed

    Assad, Mohamad; Parelle, Julien; Cazaux, David; Gimbert, Frédéric; Chalot, Michel; Tatin-Froux, Fabienne

    2016-03-01

    Tailings dumps require mercury stabilization to prevent air pollution by evaporated mercury, which can be achieved through plant covers. Plants are considered a net sink for atmospheric Hg via incorporation into leaf tissues. However, most studies related to Hg uptake by plants have considered plants exposed to only atmospheric Hg, whereas in the case of tailings dumps, plants are potentially exposed to both soil and atmospheric Hg. The goal of this work is to evaluate the relative contributions of root and atmospheric pathways by growing poplar (Populus trichocarpa X Populus maximowiczii/var Skado) cuttings on either control or polluted substrates and under either natural or controlled exposure conditions. We showed that foliar Hg concentrations significantly increased with age, reaching 120 ng g(-1) dry mass when poplars were exposed to Hg-contaminated substrate under natural exposure. Remarkably, we did not observe significantly different Hg concentrations in poplar leaves grown on either the control or polluted substrates when cultivated together in growth chambers. Our set of data prompted us to conclude that Hg entry into poplar leaves is exclusively through an atmospheric pathway. Our results are discussed in line with existing literature. PMID:26694893

  2. Vulnerability to drought-induced cavitation in poplars: synthesis and future opportunities.

    PubMed

    Fichot, Régis; Brignolas, Franck; Cochard, Hervé; Ceulemans, Reinhart

    2015-07-01

    Vulnerability to drought-induced cavitation is a key trait of plant water relations. Here, we summarize the available literature on vulnerability to drought-induced cavitation in poplars (Populus spp.), a genus of agronomic, ecological and scientific importance. Vulnerability curves and vulnerability parameters (including the water potential inducing 50% loss in hydraulic conductivity, P50) were collected from 37 studies published between 1991 and 2014, covering a range of 10 species and 12 interspecific hybrid crosses. Results of our meta-analysis confirm that poplars are among the most vulnerable woody species to drought-induced cavitation (mean P50  = -1.44 and -1.55 MPa across pure species and hybrids, respectively). Yet, significant variation occurs among species (P50 range: 1.43 MPa) and among hybrid crosses (P50 range: 1.12 MPa), within species and hybrid crosses (max. P50 range reported: 0.8 MPa) as well as in response to environmental factors including nitrogen fertilization, irradiance, temperature and drought (max. P50 range reported: 0.75 MPa). Potential implications and gaps in knowledge are discussed in the context of poplar cultivation, species adaptation and climate modifications. We suggest that poplars represent a valuable model for studies on drought-induced cavitation, especially to elucidate the genetic and molecular basis of cavitation resistance in Angiosperms. PMID:25444560

  3. Poplar for the phytomanagement of boron contaminated sites.

    PubMed

    Robinson, B H; Green, S R; Chancerel, B; Mills, T M; Clothier, B E

    2007-11-01

    Boron (B) is a widespread environmental contaminant that is mobile relative to other trace elements. We investigated the potential of hybrid poplar (Populus sp.) for B phytomanagement using a lysimeter experiment and a field trial on B-contaminated wood-waste. In both studies, poplars enhanced evapotranspiration from the wood-waste, reduced B leaching, and accumulated B in the aerial portions of the tree. When grown in a substrate containing 30 mg/kg B, poplar leaves had an average B concentration of 845 mg/kg, while the stems contained 21 mg/kg B. Leaf B concentrations increased linearly with leaf age. A decomposition experiment revealed that abscised leaves released 14% of their B during the winter months. Fertiliser application enhanced tree growth without decreasing the leaf B concentrations. Harvesting alternate rows of trees on a contaminated site would reduce leaching from the site while removing B. Harvested plant material may provide bioenergy, stock fodder, or an amendment for B-deficient soils. PMID:17382438

  4. Response of transgenic poplar overexpressing cytosolic glutamine synthetase to phosphinothricin.

    PubMed

    Pascual, María Belén; Jing, Zhong Ping; Kirby, Edward G; Cánovas, Francisco M; Gallardo, Fernando

    2008-01-01

    Glutamine synthetase (GS) is the main enzyme involved in ammonia assimilation in plants and is the target of phosphinothricin (PPT), an herbicide commonly used for weed control in agriculture. As a result of the inhibition of GS, PPT also blocks photorespiration, resulting in the depletion of leaf amino acid pools leading to the plant death. Hybrid transgenic poplar (Populus tremula x P. alba INRA clone 7171-B4) overexpressing cytosolic GS is characterized by enhanced vegetative growth [Gallardo, F., Fu, J., Cantón, F.R., García-Gutiérrez, A., Cánovas, F.M., Kirby, E.G., 1999. Expression of a conifer glutamine synthetase gene in transgenic poplar. Planta 210, 19-26; Fu, J., Sampalo, R., Gallardo, F., Cánovas, F.M., Kirby, E.G., 2003. Assembly of a cytosolic pine glutamine synthetase holoenzyme in leaves of transgenic poplar leads to enhanced vegetative growth in young plants. Plant Cell Environ. 26, 411-418; Jing, Z.P., Gallardo, F., Pascual, M.B., Sampalo, R., Romero, J., Torres de Navarra, A., Cánovas, F.M., 2004. Improved growth in a field trial of transgenic hybrid poplar overexpressing glutamine synthetase. New Phytol. 164, 137-145], increased photosynthetic and photorespiratory capacities [El-Khatib, R.T., Hamerlynck, E.P., Gallardo, F., Kirby, E.G., 2004. Transgenic poplar characterized by ectopic expression of a pine cytosolic glutamine synthetase gene exhibits enhanced tolerance to water stress. Tree Physiol. 24, 729-736], enhanced tolerance to water stress (El-Khatib et al., 2004), and enhanced nitrogen use efficiency [Man, H.-M., Boriel, R., El-Khatib, R.T., Kirby, E.G., 2005. Characterization of transgenic poplar with ectopic expression of pine cytosolic glutamine synthetase under conditions of varying nitrogen availability. New Phytol. 167, 31-39]. In vitro plantlets of GS transgenic poplar exhibited enhanced resistance to PPT when compared with non-transgenic controls. After 30 days exposure to PPT at an equivalent dose of 275 g ha(-1), growth

  5. Properties of recycled polypropylene based composites incorporating treated hardwood sawdust

    NASA Astrophysics Data System (ADS)

    Shulga, Galia; Jaunslavietis, Jevgenijs; Ozolins, Jurijs; Neiberte, Brigita; Verovkins, Anrijs; Vitolina, Sanita; Shakels, Vadims

    2016-05-01

    The effect of different treatment of hardwood sawdust under mild conditions on contact angles, adhesion energy and water sorption was studied. A comparison of these indices for the hardwood treated sawdust and the composites filled with them was performed. The treatment promoted the compatibility between the recycled polypropylene and the hardwood filler. The inclusion of the lignin-based compatibiliser in the composite, containing the ammoxidised wood filler, essentially improved its mechanical properties.

  6. Analysis of 4,664 high-quality sequence-finished poplar full-length

    SciTech Connect

    Ralph, S.; Gunter, Lee E; Tuskan, Gerald A; Douglas, Carl; Holt, Robert A.; Jones, Steven; Marra, Marco; Bohlmann, J.

    2008-01-01

    The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL)-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa x P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones for genes that were differentially expressed in

  7. The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

    SciTech Connect

    Noh, Seol Ah Choi, Young-Im Cho, Jin-Seong Lee, Hyoshin

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. - Highlights: • We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa). • We examine effects of overexpression of PagBEE3L on growth in poplar. • We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants. • BEE3L protein plays an important role in the development of plant stem.

  8. Effective energy output per cord of air-dried wood in five native, american hardwoods from a typical Tennessee woodpile

    SciTech Connect

    Walker, C.L. Jr.

    1993-07-01

    Calories per gram, moisture content, and density were determined for five species of equally seasoned hardwood. These data were used to calculate the effective British Thermal Unit (BTU) per cord in Quercus alba (white oak), Quercus velutina (black oak), Liriodendron tulipifera (yellow poplar), Carya ovata (shagbark hickory), and Cornus florida (flowering dogwood). These species were compared at typical moisture contents on an available-heat-per-volume basis to determine the best woodfuel value for the homeowner as well as for industry. While calories per gram were similar across species, the differing moisture contents and densities produced significant differences in the amount of available heat per volume of wood. 7 refs., 5 figs., 3 tabs.

  9. 78 FR 68297 - Hardwood Lumber and Hardwood Plywood Promotion, Research and Information Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    .... Since drying normally reduces the width of boards, lumber may be sold on measurement taken before going into the kiln (net measurement prior to kiln drying is commonly referred to as gross tally) or... firm.\\2\\ \\1\\ National Hardwood Lumber Association Rules for the Measurement and Inspection of...

  10. Symplastic phloem loading in poplar.

    PubMed

    Zhang, Cankui; Han, Lu; Slewinski, Thomas L; Sun, Jianlei; Zhang, Jing; Wang, Zeng-Yu; Turgeon, Robert

    2014-09-01

    Sap is driven through phloem sieve tubes by an osmotically generated pressure gradient between source and sink tissues. In many plants, source pressure results from thermodynamically active loading in which energy is used to transfer sucrose (Suc) from mesophyll cells to the phloem of leaf minor veins against a concentration gradient. However, in some species, almost all trees, correlative evidence suggests that sugar migrates passively through plasmodesmata from mesophyll cells into the sieve elements. The possibility of alternate loading mechanisms has important ramifications for the regulation of phloem transport and source-sink interactions. Here, we provide experimental evidence that, in gray poplar (Populus tremula × Populus alba), Suc enters the phloem through plasmodesmata. Transgenic plants were generated with yeast invertase in the cell walls to prevent Suc loading by this route. The constructs were driven either by the constitutive 35S promoter or the minor vein-specific galactinol synthase promoter. Transgenic plants grew at the same rate as the wild type without symptoms of loading inhibition, such as accumulation of carbohydrates or leaf chlorosis. Rates of photosynthesis were normal. In contrast, alfalfa (Medicago sativa) plants, which have limited numbers of plasmodesmata between mesophyll and phloem, displayed typical symptoms of loading inhibition when transformed with the same DNA constructs. The results are consistent with passive loading of Suc through plasmodesmata in poplar. We also noted defense-related symptoms in leaves of transgenic poplar when the plants were abruptly exposed to excessively high temperatures, adding to evidence that hexose is involved in triggering the hypersensitive response. PMID:25056922

  11. 78 FR 76857 - Hardwood Plywood From China; Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... notice in the Federal Register on June 19, 2013 (78 FR 36791). The hearing was held in Washington, DC, on... COMMISSION Hardwood Plywood From China; Determinations On the basis of the record \\1\\ developed in the... of imports of hardwood plywood from China provided for in subheading(s) 4412.10; 4412.31;...

  12. Synergy of agroforestry and bottomland hardwood afforestation

    USGS Publications Warehouse

    Twedt, D.J.; Portwood, J.

    2003-01-01

    Afforestation of bottomland hardwood forests has historically emphasized planting heavy-seeded tree species such as oak (Quercus spp.) and pecan (Caryaillinoensis) with little or no silvicultural management during stand development. Slow growth of these tree species, herbivory, competing vegetation, and limited seed dispersal, often result in restored sites that are slow to develop vertical vegetation structure and have limited tree diversity. Where soils and hydrology permit, agroforestry can provide transitional management that mitigates these historical limitations on converting cropland to forests. Planting short-rotation woody crops and intercropping using wide alleyways are two agroforestry practices that are well suited for transitional management. Weed control associated with agroforestry systems benefits planted trees by reducing competition. The resultant decrease in herbaceous cover suppresses small mammal populations and associated herbivory of trees and seeds. As a result, rapid vertical growth is possible that can 'train' under-planted, slower-growing, species and provide favorable environmental conditions for naturally invading trees. Finally, annual cropping of alleyways or rotational pulpwood harvest of woody crops provides income more rapidly than reliance on future revenue from traditional silviculture. Because of increased forest diversity, enhanced growth and development, and improved economic returns, we believe that using agroforestry as a transitional management strategy during afforestation provides greater benefits to landowners and to the environment than does traditional bottomland hardwood afforestation.

  13. Continuous steam hydrolysis of tulip poplar

    SciTech Connect

    Fieber, C.A.; Roberts, R.S.; Faass, G.S.; Muzzy, J.D.; Colcord, A.R.; Bery, M.K.

    1982-01-01

    The continuous hydrolysis of poplar chips by steam at 300-350 psi resulted in the separation of hemicellulose (I) cellulose and lignin components. The I fraction was readily depolymerised by steam to acetic acid, furfural, methanol, and xylose.

  14. Finding Fingerprints of Selection in Poplar Genomes

    SciTech Connect

    Tuskan, Gerald

    2014-10-02

    Jerry Tuskan of Oak Ridge National Laboratory and the DOE JGI talks about poplar trees as models for selective adaptation to an environment. This video complements a study published ahead online August 24, 2014 in Nature Genetics.

  15. Finding Fingerprints of Selection in Poplar Genomes

    ScienceCinema

    Tuskan, Gerald

    2014-10-28

    Jerry Tuskan of Oak Ridge National Laboratory and the DOE JGI talks about poplar trees as models for selective adaptation to an environment. This video complements a study published ahead online August 24, 2014 in Nature Genetics.

  16. PoplarGene: poplar gene network and resource for mining functional information for genes from woody plants

    PubMed Central

    Liu, Qi; Ding, Changjun; Chu, Yanguang; Chen, Jiafei; Zhang, Weixi; Zhang, Bingyu; Huang, Qinjun; Su, Xiaohua

    2016-01-01

    Poplar is not only an important resource for the production of paper, timber and other wood-based products, but it has also emerged as an ideal model system for studying woody plants. To better understand the biological processes underlying various traits in poplar, e.g., wood development, a comprehensive functional gene interaction network is highly needed. Here, we constructed a genome-wide functional gene network for poplar (covering ~70% of the 41,335 poplar genes) and created the network web service PoplarGene, offering comprehensive functional interactions and extensive poplar gene functional annotations. PoplarGene incorporates two network-based gene prioritization algorithms, neighborhood-based prioritization and context-based prioritization, which can be used to perform gene prioritization in a complementary manner. Furthermore, the co-functional information in PoplarGene can be applied to other woody plant proteomes with high efficiency via orthology transfer. In addition to poplar gene sequences, the webserver also accepts Arabidopsis reference gene as input to guide the search for novel candidate functional genes in PoplarGene. We believe that PoplarGene (http://bioinformatics.caf.ac.cn/PoplarGene and http://124.127.201.25/PoplarGene) will greatly benefit the research community, facilitating studies of poplar and other woody plants. PMID:27515999

  17. PoplarGene: poplar gene network and resource for mining functional information for genes from woody plants.

    PubMed

    Liu, Qi; Ding, Changjun; Chu, Yanguang; Chen, Jiafei; Zhang, Weixi; Zhang, Bingyu; Huang, Qinjun; Su, Xiaohua

    2016-01-01

    Poplar is not only an important resource for the production of paper, timber and other wood-based products, but it has also emerged as an ideal model system for studying woody plants. To better understand the biological processes underlying various traits in poplar, e.g., wood development, a comprehensive functional gene interaction network is highly needed. Here, we constructed a genome-wide functional gene network for poplar (covering ~70% of the 41,335 poplar genes) and created the network web service PoplarGene, offering comprehensive functional interactions and extensive poplar gene functional annotations. PoplarGene incorporates two network-based gene prioritization algorithms, neighborhood-based prioritization and context-based prioritization, which can be used to perform gene prioritization in a complementary manner. Furthermore, the co-functional information in PoplarGene can be applied to other woody plant proteomes with high efficiency via orthology transfer. In addition to poplar gene sequences, the webserver also accepts Arabidopsis reference gene as input to guide the search for novel candidate functional genes in PoplarGene. We believe that PoplarGene (http://bioinformatics.caf.ac.cn/PoplarGene and http://124.127.201.25/PoplarGene) will greatly benefit the research community, facilitating studies of poplar and other woody plants. PMID:27515999

  18. Elucidation of Factors Effecting Enzymatic Saccharification using Transgenic Hardwoods

    NASA Astrophysics Data System (ADS)

    Min, Douyong

    Three groups of transgenic wood samples were used as starting materials to elucidate the recalcitrance of enzymatic saccharification with/without pretreatments. The first group of transgenic wood samples is low lignin P. trichocarpa. The second group is low xylan P. trichocarpa. The third one is 12 hybrid poplars which have different levels of S/V ratio and lignin content. Four pretreatments were carried out in this research including dilute sulfuric acid, green liquor, auto hydrolysis and ozone delignification. The behavior among pretreatments as a function of removal of lignin appears to be different. Lignin is the major factor of recalcitrance of the lignocellulosic material to ethanol conversion process. Xylan also plays key role in this process. In addition, the crude milled wood lignin was isolated from these three groups of transgenic samples. Lignin carbohydrate complexes was characterized by 1H-13C HMQC and 13C NMR. Thus the effect of LCCs on enzymatic saccharification was elucidated. High S/V ratio propels the lignin removal during pretreatments however; high S/V ratio retards the enzymatic saccharification on the lignocellulosic material without pretreatments. The level of LCCs linkages accounts for additional recalcitrance of the lignocellulosic material to ethanol conversion process. The amount of LCCs linkages is affected by xylan content, lignin content and S/V ratio.

  19. The metagenome of an anaerobic microbial community decomposing poplar wood chips

    SciTech Connect

    van der Lelie D.; Taghavi, S.; McCorkle, S. M.; Li, L.-L.; Malfatti, S. A.; Monteleone, D.; Donohoe, B. S.; Ding, S.-Y.; Adney, W. S.; Himmel, M. E.; Tringe, S. G.

    2012-05-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic 'secretomes' that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to

  20. The Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

    PubMed Central

    van der Lelie, Daniel; Taghavi, Safiyh; McCorkle, Sean M.; Li, Luen-Luen; Malfatti, Stephanie A.; Monteleone, Denise; Donohoe, Bryon S.; Ding, Shi-You; Adney, William S.; Himmel, Michael E.; Tringe, Susannah G.

    2012-01-01

    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic ‘secretomes’ that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point

  1. In situ measurements of root exudation in three hardwood species in southern Indiana

    NASA Astrophysics Data System (ADS)

    O'Connor, D. A.; Brzostek, E. R.; Fisher, J. B.; Phillips, R.

    2012-12-01

    Root exudation - the release of soluble organic compounds to soil - has long been considered a black box in ecology owing to methodological difficulties associated with measuring this flux in situ. This knowledge gap is significant given recent findings that suggest exudate inputs are appreciable in magnitude (2-5% of net primary production) and are coupled to microbial activities, nutrient release and soil organic matter decomposition. We developed a novel experimental system for collecting exudates from intact roots of field-grown trees using cuvettes filled with sterile glass beads. We measured root exudation for three tree species in ~80 year old mixed hardwood forest in south central Indiana, USA in the summer of 2012. Exudation rates varied from 0 to 1413 ug C/g root/day, and differed by sampling date and among trees species. Overall, rates were greater in early relative to late July, and greater in sugar maple (Acer saccharum) and white oak (Quercus alba) relative to tulip poplar (Liriodendron tulipifera). Across all species, exudation rates were correlated with root mass, indicating that greater allocation to roots likely increases the amount of C available to fuel soil microbial activity. Collectively, the results of this study should enable us to develop improved model parameterizations of the C costs associated with nutrient acquisition, an important feedback for predicting the role of vegetation in mediating climate change.

  2. AmeriFlux US-Wi1 Intermediate hardwood (IHW)

    SciTech Connect

    Chen, Jiquan

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Wi1 Intermediate hardwood (IHW). Site Description - The Wisconsin Intermediate Hardwoods site is located in the Washburn Ranger District of the Chequamegon National Forest. A member of the northern coniferous-deciduous biome, surveys from the mid-19th century indicate the region consisted of a mixed stand of red, white, and jack pines. After extensive timber harvesting, wildfires, and farming activity, the region turned into a fragmented mosaic of stands of various ages and composition. The intermediate hardwoods site is one of ten sites that collectively represent the successional stages of development in the predominant stand types of a physically homogeneous landscape. In 2001, northern hardwood stands of all ages occupied 45% of the region.

  3. Species characterization and responses of subcortical insects to trap-logs and ethanol in a hardwood biomass plantation: Subcortical insects in hardwood plantations

    SciTech Connect

    Coyle, David R.; Brissey, Courtney L.; Gandhi, Kamal J. K.

    2015-01-02

    1. We characterized subcortical insect assemblages in economically important eastern cottonwood (Populus deltoides Bartr.), sycamore (Platanus occidentalis L.) and sweetgum (Liquidambar styraciflua L.) plantations in the southeastern U.S.A. Furthermore, we compared insect responses between freshly-cut plant material by placing traps directly over cut hardwood logs (trap-logs), traps baited with ethanol lures and unbaited (control) traps. 2. We captured a total of 15 506 insects representing 127 species in four families in 2011 and 2013. Approximately 9% and 62% of total species and individuals, respectively, and 23% and 79% of total Scolytinae species and individuals, respectively, were non-native to North America. 3. We captured more Scolytinae using cottonwood trap-logs compared with control traps in both years, although this was the case with sycamore and sweetgum only in 2013. More woodborers were captured using cottonwood and sweetgum trap-logs compared with control traps in both years, although only with sycamore in 2013. 4. Ethanol was an effective lure for capturing non-native Scolytinae; however, not all non-native species were captured using ethanol lures. Ambrosiophilus atratus (Eichhoff) and Hypothenemus crudiae (Panzer) were captured with both trap-logs and control traps, whereas Coccotrypes distinctus (Motschulsky) and Xyleborus glabratus Eichhoff were only captured on trap-logs. 5. Indicator species analysis revealed that certain scolytines [e.g. Cnestus mutilates (Blandford) and Xylosandrus crassiusculus (Motschulsky)] showed significant associations with trap-logs or ethanol baits in poplar or sweetgum trap-logs. In general, the species composition of subcortical insects, especially woodboring insects, was distinct among the three tree species and between those associated with trap-logs and control traps.

  4. Greater efficiency of water use in poplar clones having a delayed response of mesophyll conductance to drought.

    PubMed

    Théroux Rancourt, Guillaume; Éthier, Gilbert; Pepin, Steeve

    2015-02-01

    Improvement of water use efficiency is a key objective to improve the sustainability of cultivated plants, especially fast growing species with high water consumption like poplar. It is well known that water use efficiency (WUE) varies considerably among poplar genotypes, and it was recently suggested that the use of the mesophyll-to-stomatal conductance ratio (gm/gs) would be an appropriate trait to improve WUE. The responses of 7-week-old cuttings of four hybrid poplar clones and one native Balsam poplar (Populus balsamifera L.) to a water stress-recovery cycle were examined to evaluate the relation between the gm/gs ratio and transpiration efficiency (TE), a leaf-level component of WUE. A contrasting gs response to water stress was observed among the five clones, from stomatal closure early on during soil drying up to limited closure in Balsam poplar. However in the hybrids, the decline in gm was consistently delayed by a few days compared with gs. Moreover, in the most water use-efficient hybrids, the recovery following rehydration occurred faster for gm than for gs. Thus, the delay in the response of gm to drought and its faster recovery upon rewatering increased the gm/gs of the hybrids and this ratio scaled positively with TE. Our results support the use of the gm/gs ratio to select genotypes with improved WUE, and the notion that breeding strategies focusing mainly on stomatal responses to soil drying should also look for a strong curvilinearity between net carbon assimilation rate and gs, the indication of a significant increase in gm/gs in the earlier stages of stomatal closure. PMID:25721370

  5. Forest biorefinery: Potential of poplar phytochemicals as value-added co-products.

    PubMed

    Devappa, Rakshit K; Rakshit, Sudip K; Dekker, Robert F H

    2015-11-01

    The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species. PMID:25733011

  6. Transgenic poplar expressing the pine GS1a show alterations in nitrogen homeostasis during drought.

    PubMed

    Molina-Rueda, Juan Jesús; Kirby, Edward G

    2015-09-01

    Transgenic hybrid poplars engineered to express ectopically the heterologous pine cytosolic GS1a display a number of significant pleiotropic phenotypes including enhanced growth, enhanced nitrogen use efficiency, and resistance to drought stress. The present study was undertaken in order to assess mechanisms whereby ectopic expression of pine GS1a in transgenic poplars results in enhanced agronomic phenotypes. Microarray analysis using the Agilent Populus whole genome array has allowed identification of genes differentially expressed between wild type (WT) and GS transgenics in four tissues (sink leaves, source leaves, stems, and roots) under three growth conditions (well-watered, drought, and recovery). Analysis revealed that differentially expressed genes in functional categories related to nitrogen metabolism show a trend of significant down-regulation in GS poplars compared to the WT, including genes encoding nitrate and nitrite reductases. The down-regulation of these genes was verified using qPCR, and downstream effects were further tested using NR activity assays. Results suggest that higher glutamine levels in GS transgenics regulate nitrate uptake and reduction. Transcript levels of nitrogen-related genes in leaves, including GS/GOGAT cycle enzymes, aspartate aminotransferase, GABA shunt enzymes, photorespiration enzymes, asparagine synthetase, phenylalanine ammonia lyase, isocitrate dehydrogenase, and PII, were also assessed using qPCR revealing significant differences between GS poplars and the WT. Moreover, metabolites related to these differentially expressed genes showed alterations in levels, including higher levels of GABA, hydroxyproline, and putrescine in the GS transgenic. These alterations in nitrogen homeostasis offer insights into mechanisms accounting for drought tolerance observed in GS poplars. PMID:26113157

  7. A System for Dosage-Based Functional Genomics in Poplar[OPEN

    PubMed Central

    2015-01-01

    Altering gene dosage through variation in gene copy number is a powerful approach to addressing questions regarding gene regulation, quantitative trait loci, and heterosis, but one that is not easily applied to sexually transmitted species. Elite poplar (Populus spp) varieties are created through interspecific hybridization, followed by clonal propagation. Altered gene dosage relationships are believed to contribute to hybrid performance. Clonal propagation allows for replication and maintenance of meiotically unstable ploidy or structural variants and provides an alternative approach to investigating gene dosage effects not possible in sexually propagated species. Here, we built a genome-wide structural variation system for dosage-based functional genomics and breeding of poplar. We pollinated Populus deltoides with gamma-irradiated Populus nigra pollen to produce >500 F1 seedlings containing dosage lesions in the form of deletions and insertions of chromosomal segments (indel mutations). Using high-precision dosage analysis, we detected indel mutations in ∼55% of the progeny. These indels varied in length, position, and number per individual, cumulatively tiling >99% of the genome, with an average of 10 indels per gene. Combined with future phenotype and transcriptome data, this population will provide an excellent resource for creating and characterizing dosage-based variation in poplar, including the contribution of dosage to quantitative traits and heterosis. PMID:26320226

  8. Use of wetlands for production of woody plants for fuels and petrochemical substitutes. [Alders, willows, poplars

    SciTech Connect

    Farnham, R.S.; Read, P.

    1981-03-01

    Work performed on this project in the past year has included the evaluations of natural stands productivity for wetland biomass species; propagation studies with alder, willow and poplar species; nursery establishment for production of cultivars and evaluation of wetland soils suitable for production of woody biomass species. Also a biomass research facility has been established in N. Minnesota suitable for long-term research and demonstration. Propagation research has included both micro and macro propagation techniques with native willows, selected willow clones from Sweden, alder seed selection from Finland and hybrid poplar clones from US Forest Service, Rhinelander, Wisconsin. Approximately 100,000 rooted plants will be available for field research by June 1, 1981.

  9. AmeriFlux US-Wi3 Mature hardwood (MHW)

    SciTech Connect

    Chen, Jiquan

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Wi3 Mature hardwood (MHW). Site Description - The Wisconsin Mature Hardwood site is located in the Washburn Ranger District of the northeastern section of Chequamegon National Forest. A member of the northern coniferous-deciduous biome, surveys from the mid-19th century indicate the region consisted of a mixed stand of red, white, and jack pines. After extensive timber harvesting, wildfires, and farming activity, the region turned into a fragmented mosaic of stands of various ages and composition. As an assemblage, the ten Wisconsin sites are indicative of the successional stages of development in the predominant stand types of a physically homogeneous landscape. The mature hardwood stand represents a typical naturally regenerated second-growth forest, free of anthropogenic disturbances for at least 70 years.

  10. Bottomland Hardwood Forests along the Upper Mississippi River

    USGS Publications Warehouse

    Yin, Y.; Nelson, J.C.; Lubinski, S.J.

    1997-01-01

    Bottomland hardwood forests along the United States' Upper Mississippi River have been drastically reduced in acreage and repeatedly logged during the nineteenth and twentieth centuries. Conversion to agricultural land, timber harvesting, and river modifications for flood prevention and for navigation were the primary factors that caused the changes. Navigation structures and flood-prevention levees have altered the fluvial geomorphic dynamics of the river and floodplain system. Restoration and maintenance of the diversity, productivity, and natural regeneration dynamics of the bottomland hardwood forests under the modified river environment represent a major management challenge.

  11. Prioritizing bottomland hardwood forest sites for protection and augmentation

    USGS Publications Warehouse

    Carter, J.; Biagas, J.

    2007-01-01

    Bottomland hardwood forest has been greatly diminished by conversion to agriculture. Less than 25% of the pre-Columbian bottomland hardwood forests remain in the southeastern United States. Because of the valuable ecological and hydrological functions performed by these forests, their conservation and restoration has been a high priority. Part of these restoration efforts has focused on developing tools that can be used for both assessments at the landscape level and policy implementation at the local level. The distribution of bottomland hardwood forests in the Cache and White River watersheds in eastern Arkansas were examined using existing GIS databases. Criteria were developed to select areas that should be conserved or augmented for wildlife habitat. Over 67% of the study area was classified as agriculture, with bottomland hardwood forest the next largest habitat class. The thickness of a forest fragment was defined as the radius of the largest circle that can be inscribed in a fragment. Thickness was used in three ways. First, individual forest fragments were identified and selected based on ecological function using criteria we established. Second, individual fragments that were too small to support interior species, but large enough that if moderately augmented they could recover that function, were identified and selected. These augmentable fragments were further prioritized by adjacency to habitat that might be suitable for reforestation, namely agriculture. Third, watersheds were prioritized for conservation and augmentation based on the size and distributions of forest fragment thickness and area within each watershed.

  12. South Fork Telephone Switchboard Building, interior west room showing hardwood ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South Fork Telephone Switchboard Building, interior west room showing hardwood floor; view south - Fort McKinley, South Fork Telephone Switchboard Building, South side of Weymouth Way, approximately 100 feet west of East Side Drive, Great Diamond Island, Portland, Cumberland County, ME

  13. Hardwood biochar influences calcareous soil physicochemical and microbiological status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial com...

  14. Hexahydro-1,3,5-trinitro-1,3,5-triazine translocation in poplar trees

    SciTech Connect

    Thompson, P.L.; Ramer, L.A.; Schnoor, J.L.

    1999-02-01

    This article evaluates the translocation of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in hybrid poplar trees (Populus deltoides x nigra, DN34) grown in hydroponic solutions. Mass balances with [U-{sup 14}C]RDX were used to assess RDX translocation. Up to 60% of the RDX uptaken by the tree accumulated in leaf tissues. Analysis of plant extracts by high-performance liquid chromatography equipped with radiochemical detection indicated that RDX was not significantly transformed during exposure periods of up to 7 d. The bioaccumulation of RDX may be an important concern for phytoremediation efforts.

  15. 6. GENERAL VIEW EAST FROM ROOFTOP OF POPLAR FOREST TOWARDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENERAL VIEW EAST FROM ROOFTOP OF POPLAR FOREST TOWARDS SUMMER KITCHEN (FOREGROUND) AND DAIRY; CHIMNEY OF SOUTH TENANT HOUSE BARELY VISIBLE THROUGH TREES; EAST PRIVY RARELY VISIBLE OVER EAST MOUND (1987) - Poplar Forest, Summer Kitchen, State Route 661, Forest, Bedford County, VA

  16. Morphological and molecular characterization of two Aphelenchoides from poplar leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a long-term, large network study of the ecology of plant endophytes in native habitats, various nematodes were found. Two poplar species, Populus angustifolia (narrowleaf cottonwood) and P. trichocarpa (black poplar) represent important ecological and genomic models now used in ongoing plant...

  17. Increasing hardwood fiber supplies through improved bark utilization

    SciTech Connect

    Einspahr, D.W.; Harder, M.L.

    1980-09-01

    A promising approach to meeting increased demands for hardwood fiber is through the greater use of logging residues. A method of harvesting and more completely utilizing mixed hardwood stands is discussed. Most species that are difficult to debark contain fiberlike elements in the inner bark. Procedures are suggested for reducing the size of the chipped bark fraction and thus allowing removal of only bark that is low in fiber. The pulping of barks that are high in fiber will result in greater per-acre fiber production. Increases in per-acre pulp production are estimated at 50-90% for the suggested approach. Modest pulp strength increases are anticipated through the use of bark fibers.

  18. System and method for conditioning a hardwood pulp liquid hydrolysate

    SciTech Connect

    Waite, Darrell M; Arnold, Richard; St. Pierre, James; Pendse, Hemant P; Ceckler, William H

    2013-12-17

    A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hyrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

  19. System and method for conditioning a hardwood pulp liquid hydrolysate

    SciTech Connect

    Waite, Darrell; Arnold, Richard; St. Pierre, James; Pendse, Hemant P.; Ceckler, William H.

    2015-06-30

    A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hydrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

  20. Directional scattering properties of a winter deciduous hardwood canopy

    NASA Technical Reports Server (NTRS)

    Kimes, Daniel S.; Newcomb, W. Wayne

    1987-01-01

    The unique directional scattering properties of a deciduous hardwood forest without leaves during the winter period was measured in a visible and near-infrared band. A radiative transfer model was used to explore the scattering properties of such a forest. The reflectance distributions look similar to sparse homogeneous vegetation canopies. The overall reflectance distribution is a combination of the extreme azimuthal scattering behavior of tree limbs and the more typical scattering behavior of understory litter.

  1. Control of hardwood regeneration in restored carolina bay depression wetlands.

    SciTech Connect

    Moser, Lee, J.; Barton, Christopher, D.; Blake, John, I.

    2012-06-01

    Carolina bays are depression wetlands located in the coastal plain region of the eastern United States. Disturbance of this wetland type has been widespread, and many sites contain one or more drainage ditches. Restoration of bays is of interest because they are important habitats for rare flora and fauna. Previous bay restoration projects have identified flood-tolerant woody competitors in the seedbank and re-sprouting as impediments to the establishment of desired herbaceous wetland vegetation communities. We restored 3 bays on the Savannah River Site, South Carolina, by plugging drainage ditches, harvesting residual pine/hardwood stands within the bays, and monitoring the vegetative response of the seedbank to the hydrologic change. We applied a foliar herbicide on one-half of each bay to control red maple (Acerrubrum), sweetgum (Liquidambar styraciflua), and water oak (Quercus nigra) sprouting, and we tested its effectiveness across a hydrologic gradient in each bay. Hardwood regeneration was partially controlled by flooding in bays that exhibited long growing season hydroperiods. The findings also indicated that herbicide application was an effective means for managing hardwood regeneration and re-sprouting in areas where hydrologic control was ineffective. Herbicide use had no effect on species richness in the emerging vegetation community. In late-season drawdown periods, or in bays where hydroperiods are short, more than one herbicide application may be necessary.

  2. Comparison between soil and biomass carbon in adjacent hardwood and red pine forests

    SciTech Connect

    Perala, D.A.; Rollinger, J.L.; Wilson, D.M.

    1995-06-01

    The distribution of carbon in soil and biomass was studied across Minnesota, Wisconsin, and Michigan, USA, in 40 pole-sized red pine (Pinus resinosa Ait.) plantations paired with adjacent hardwood stands. Pine and hardwood stands shared a common boundary and soil. Hardwood stands were mixed species, naturally regenerated second growth following logging. Carbon in total, standing crop averaged the same in both hardwood and red pine forest types, although the hardwoods averaged 14 years older than red pine. Coarse woody debris, shrubs, and herbs contained little carbon. Only the forest floor carbon pool was significantly different between forest types. Forest floor had a greater mass beneath red pine than hardwoods. There was no difference in total ecosystem carbon between red pine and hardwood stands. Total mineral soil aggregated across the depth profile contained the same total amount of carbon in both pine and hardwood stands; however, the carbon was found in different vertical patterns. Amounts of carbon in the upper levels of soil (0--4 cm) were higher under hardwoods, and amounts were higher under red pine at the 8--16 cm and 16--32 cm soil depths. Where July air temperatures were relatively cool, red pine stored carbon more efficiently both in the forest floor and deep in the soil. Red pine also sequestered more carbon in mineral soil with increasing April--September precipitation.

  3. Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

    PubMed

    Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

    2016-10-01

    The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality. PMID:27411672

  4. The Central Hardwoods Virtual Forest Version 2.0. [CD-ROM].

    ERIC Educational Resources Information Center

    Indiana Univ.-Purdue Univ., Indianapolis.

    This CD-ROM is the second in a series of CDs allowing students to explore the trees and animals of the northern boreal forest. Using QuickTime Virtual Reality (QTVR), the Central Hardwood Virtual Forest is designed so that students are able to see views from inside the central hardwood forest and look up or down or spin around 360 degrees. The…

  5. Poplar and its bacterial endophytes: coexistence and harmony

    SciTech Connect

    van der Lelie, D.; Taghavi, S.; Monchy, S.; Schwender, J.; Miller, L.; Ferrieri, R.; Rogers, A.; Zhu, W.; Weyens, N.; Vangronsveld, J.; Newman, L.

    2009-09-01

    Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an improved understanding of the interaction between poplar and its endophytic bacteria has the potential to provide major breakthroughs that will improve the productivity of poplar. Endophytic bacteria can improve plant growth and development in a direct or indirect way. Direct plant growth promoting mechanisms may involve nitrogen fixation, production of plant growth regulators such as auxins, cytokinins and gibberellins, and suppression of stress ethylene synthesis by 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Endophytic bacteria can indirectly benefit the plant by preventing the growth or activity of plant pathogens through competition for space and nutrients, antibiosis, production of hydrolytic enzymes, inhibition of pathogen-produced enzymes or toxins, and through systemic induction of plant defense mechanisms. Examples of applications for custom endophyte-host partnerships include improved productivity and establishment of poplar trees on marginal soils and the phytoremediation of contaminated soils and groundwater. A systems biology approach to understand the synergistic interactions between poplar and its beneficial endophytic bacteria represents an important field of research, which is facilitated by the recent sequencing of the genomes of poplar and several of its endophytic bacteria.

  6. Avian response to bottomland hardwood reforestation: the first 10 years

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.; Henne-Kerr, J.L.; Grosshuesch, D.A.

    2002-01-01

    Bttomland hardwood forests were planted on agricultural fields in Mississippi and Louisiana using either predominantly Quercus species (oaks) or Populus deltoides (eastern cottonwood). We assessed avian colonization of these reforested sites between 2 and 10 years after planting. Rapid vertical growth of cottonwoods (circa 2 - 3 m / yr) resulted in sites with forest structure that supported greater species richness of breeding birds, increased Shannon diversity indices, and supported greater territory densities than on sites planted with slower-growing oak species. Grassland birds (Spiza americana [Dickcissel], and Sturnella magna [Eastern Meadowlark]) were indicative of species breeding on oak-dominated reforestation # 10 years old. Agelaius phoeniceus (Red-winged Blackbird) and Colinus virginianus (Northern Bobwhite) characterized cottonwood reforestation # 4 years old, whereas 14 species of shrub-scrub birds (e.g., Passerina cyanea [Indigo Bunting]) and early-successional forest birds (e.g., Vireo gilvus [Warbling Vireo]) typified cottonwood reforestation 5 to 9 years after planting. Rates of daily nest survival did not differ between reforestation strategies. Nest parasitism increased markedly in older cottonwood stands, but was overwhelmed by predation as a cause of nest failure. Based on Partners in Flight prioritization scores and territory densities, the value of cottonwood reforestation for avian conservation was significantly greater than that of oak reforestation during their first 10 years. Because of benefits conferred on breeding birds, we recommend reforestation of bottomland hardwoods include a high proportion of fast-growing, early successional species such as cottonwood.

  7. Molecular analysis of poplar defense against herbivory: comparison of wound- and insect elicitor-induced gene expression.

    PubMed

    Major, Ian T; Constabel, C Peter

    2006-01-01

    In order to characterize defense responses of hybrid poplar (Populus trichocarpax P. deltoides), we profiled leaf transcript patterns elicited by wounding and by regurgitant from forest tent caterpillar (FTC; Malacosoma disstria), a Lepidopteran defoliator of poplars. Macroarrays were used to compare transcript profiles. Both FTC-regurgitant (FTC-R) and mechanical wounding with pliers elicited expression of a variety of genes, and for these genes our analysis indicated that these treatments induced qualitatively similar responses. Similarly, a comparison of responses of directly treated and systemically induced leaves indicated extensive overlap in the sets of induced genes. FTC-R was found to contain the insect-derived elicitor volicitin. The simulated herbivory treatments resulted in the induction of genes involved in poplar defense and secondary metabolism. We also identified wound-responsive genes with roles in primary metabolism, including a putative invertase, lipase, and acyl-activating enzyme; some of these genes may have roles in defense signaling. In addition, we found three unknown genes containing a ZIM motif which may represent novel transcription factors. PMID:17096789

  8. Wood and paper properties of vacuum airlift segregated juvenile poplar whole-tree chips

    SciTech Connect

    Phelps, J.E.; Isebrands, J.G.; Einspahr, D.W.; Crist, J.B.; Sturos, J.A.

    1986-01-01

    Whole tree chips from a hybrid poplar clone (Populus Tristis No.1) grown under short rotation, intensive culture (SRIC) were separated into three fractions using vacuum airlift segregation (VAS). The fractions were: accepts, which was predominantly a woody fraction; rejects, which contained less wood and more bark and twigs; and fines, which consisted mostly of bark particles. The raw material quality was evaluated and kraft pulp and paper properties were determined on the whole tree chips and each VAS fraction as well as on a 50:50 mixture of the accepts:rejects fractions. A 50:50 mixture of VAS accepts and 55-yr-old mill-run jack pine was also studied. Pulp and paper properties of the whole tree chips, the VAS accepts and rejects, and a 50:50 mixture of accepts:rejects were similar and were only slightly lower quality than those of mature aspen (Populus) chips. The 50:50 mixture of VAS accepts and mill-run jack pine was acceptable by industrial standards. These results suggest that whole tree chips from SRIC poplar stands can be mixed with conifer chips to supplement furnishes for kraft pulping.

  9. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    DOE PAGESBeta

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; et al

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have largemore » implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  10. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    SciTech Connect

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; Kumar, Rajeev

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have large implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  11. Hardwood tree growth on amended mine soils in west virginia.

    PubMed

    Wilson-Kokes, Lindsay; Delong, Curtis; Thomas, Calene; Emerson, Paul; O'Dell, Keith; Skousen, Jeff

    2013-09-01

    Each year surface mining in Appalachia disrupts large areas of forested land. The Surface Mining Control and Reclamation Act requires coal mine operators to establish a permanent vegetative cover after mining, and current practice emphasizes soil compaction and planting of competitive forage grasses to stabilize the site and control erosion. These practices hinder recolonization of native hardwood trees on these reclaimed sites. Recently reclamation scientists and regulators have encouraged re-establishment of hardwood forests on surface mined land through careful selection and placement of rooting media and proper selection and planting of herbaceous and tree species. To evaluate the effect of rooting media and soil amendments, a 2.8-ha experimental plot was established, with half of the plot being constructed of weathered brown sandstone and half constructed of unweathered gray sandstone. Bark mulch was applied to an area covering both sandstone types, and the ends of the plot were hydroseeded with a tree-compatible herbaceous seed mix, resulting in eight soil treatments. Twelve hardwood tree species were planted, and soil chemical properties and tree growth were measured annually from 2007 to 2012. After six growing seasons, average tree volume index was higher for trees grown on brown sandstone (5333 cm) compared with gray sandstone (3031 cm). Trees planted in mulch outperformed trees on nonmulched treatments (volume index of 6187 cm vs. 4194 cm). Hydroseeding with a tree-compatible mix produced greater ground cover (35 vs. 15%) and resulted in greater tree volume index than nonhydroseed areas (5809 vs. 3403 cm). Soil chemical properties were improved by mulch and improved tree growth, especially on gray sandstone. The average pH of brown sandstone was 5.0 to 5.4, and gray sandstone averaged pH 6.9 to 7.7. The mulch treatment on gray sandstone resulted in tree growth similar to brown sandstone alone and with mulch. After 6 yr, tree growth on brown sandstone was

  12. In Vivo Biotransformation of 3,3′,4,4′-Tetrachlorobiphenyl by Whole Plants−Poplars and Switchgrass

    PubMed Central

    2009-01-01

    Polychlorinated biphenyls (PCBs) are widely distributed persistent organic pollutants. In vitro research has shown that plant cell cultures might transform lower chlorinated congeners to hydroxylated PCBs, but there are few studies on in vivo metabolism of PCBs by intact whole plants. In this research, poplar plants (Populus deltoides × nigra, DN34) and switchgrass (Panicum vigratum, Alamo) were hydroponically exposed to 3,3′,4,4′-tetrachlorobiphenyl (CB77). Metabolism in plants occurred rapidly, and metabolites were detected after only a 24 h exposure. Rearrangement of chlorine atoms and dechlorination of CB77 by plants was unexpectedly observed. In addition, poplars were able to hydroxylate CB77 and the metabolite 6-hydroxy-3,3′,4,4′-tetrachlorobiphenyl (6-OH-CB77) was identified and quantified. Hybrid poplar was able to hydroxylate CB77, but switchgrass was not, suggesting that enzymatic transformations are plant specific. Sulfur-containing metabolites (from the action of sulfotransferases) were investigated in this study, but they were not detected in either poplar or switchgrass. PMID:19848168

  13. Analysis of 4,664 high-quality sequence-finished poplar full-length cDNA clones and their utility for the discovery of genes responding to insect feeding

    PubMed Central

    Ralph, Steven G; Chun, Hye Jung E; Cooper, Dawn; Kirkpatrick, Robert; Kolosova, Natalia; Gunter, Lee; Tuskan, Gerald A; Douglas, Carl J; Holt, Robert A; Jones, Steven JM; Marra, Marco A; Bohlmann, Jörg

    2008-01-01

    Background The genus Populus includes poplars, aspens and cottonwoods, which will be collectively referred to as poplars hereafter unless otherwise specified. Poplars are the dominant tree species in many forest ecosystems in the Northern Hemisphere and are of substantial economic value in plantation forestry. Poplar has been established as a model system for genomics studies of growth, development, and adaptation of woody perennial plants including secondary xylem formation, dormancy, adaptation to local environments, and biotic interactions. Results As part of the poplar genome sequencing project and the development of genomic resources for poplar, we have generated a full-length (FL)-cDNA collection using the biotinylated CAP trapper method. We constructed four FLcDNA libraries using RNA from xylem, phloem and cambium, and green shoot tips and leaves from the P. trichocarpa Nisqually-1 genotype, as well as insect-attacked leaves of the P. trichocarpa × P. deltoides hybrid. Following careful selection of candidate cDNA clones, we used a combined strategy of paired end reads and primer walking to generate a set of 4,664 high-accuracy, sequence-verified FLcDNAs, which clustered into 3,990 putative unique genes. Mapping FLcDNAs to the poplar genome sequence combined with BLAST comparisons to previously predicted protein coding sequences in the poplar genome identified 39 FLcDNAs that likely localize to gaps in the current genome sequence assembly. Another 173 FLcDNAs mapped to the genome sequence but were not included among the previously predicted genes in the poplar genome. Comparative sequence analysis against Arabidopsis thaliana and other species in the non-redundant database of GenBank revealed that 11.5% of the poplar FLcDNAs display no significant sequence similarity to other plant proteins. By mapping the poplar FLcDNAs against transcriptome data previously obtained with a 15.5 K cDNA microarray, we identified 153 FLcDNA clones for genes that were

  14. Degradation of softwood, hardwood, and grass lignocelluloses by two Steptomyces strains

    SciTech Connect

    Antai, S.P.; Crawford, D.L.

    1981-08-01

    Two Streptomyces strains, S. viridosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the lignin and the carbohydrate components of each lignocellulose; however, these actinomycetes were more efficient decomposers of grass lignocelluloses than of hardwood or softwood lignocelluloses. In particular, these Streptomyces strains were more efficient decomposers of grass lignins than of hardwood or softwood lignins.

  15. Poplar maintains zinc homeostasis with heavy metal genes HMA4 and PCS1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This project has identified two large gene families, HMA and ZIP, in poplar that have been greatly expanded by the latest Salicoid genome duplication in poplar. In other species, these two families have been shown to be central in both hyperaccumulators and non-hyperaccumulators In poplar, many of t...

  16. Ethanol producer looks to hardwoods as raw material

    SciTech Connect

    Anderson, E.

    1988-01-04

    Bio-Regional Energy Associates (BREA), has launched a project to produce fuel ethanol from the vast reserves of low-value hardwoods that are conveniently located around Floyd, Va., the company's home base. The typical ethanol producer, adds Brecc Avellar, BREA's technical director, has relatively few coproducts to help shoulder production costs, and even relatively few raw materials from which to choose. BREA, he says, is trying to diversify on both ends. Staengl recently outlined the company's plans to develop its wood hydrolysis technology at the International Conference on (Fuel) Alcohols and Chemicals from Biomass held at Montego Bay, Jamaica. The company, he says, is building in three stages a pilot-scale (30 to 40 tons per day) wood hydrolysis and fermentation plant. The goal is to develop markets for the most diverse and highest-value products from each of the three basic wood components - cellulose, hemicellulose and lignin.

  17. Growing poplars for research with and without mycorrhizas

    PubMed Central

    Müller, Anna; Volmer, Katharina; Mishra-Knyrim, Manika; Polle, Andrea

    2013-01-01

    During the last decades the importance of the genus Populus increased because the poplar genome has been sequenced and molecular tools for basic research have become available. Poplar species occur in different habitats and harbor large genetic variation, which can be exploited for economic applications and for increasing our knowledge on the basic molecular mechanisms of the woody life style. Poplars are, therefore, employed to unravel the molecular mechanisms of wood formation, stress tolerance, tree nutrition and interaction with other organisms such as pathogens or mycorrhiza. The basis of these investigations is the reproducible production of homogeneous plant material. In this method paper we describe techniques and growth conditions for the in vitro propagation of different poplar species (Populus × canescens, P. trichocarpa, P. tremula, and P. euphratica) and ectomycorrhizal fungi (Laccaria bicolor, Paxillus involutus) as well as for their co-cultivation for ectomycorrhizal synthesis. Maintenance and plant preparation require different multiplication and rooting media. Growth systems to cultivate poplars under axenic conditions in agar and sand cultures with and without mycorrhizal fungi are described. Transfer of the plants from in vitro to in situ conditions is critical and hardening is important to prevent high mortality. Growth and vitality of the trees in vitro and outdoors with and without ectomycorrhizas are reported. PMID:23986772

  18. Growing poplars for research with and without mycorrhizas.

    PubMed

    Müller, Anna; Volmer, Katharina; Mishra-Knyrim, Manika; Polle, Andrea

    2013-01-01

    During the last decades the importance of the genus Populus increased because the poplar genome has been sequenced and molecular tools for basic research have become available. Poplar species occur in different habitats and harbor large genetic variation, which can be exploited for economic applications and for increasing our knowledge on the basic molecular mechanisms of the woody life style. Poplars are, therefore, employed to unravel the molecular mechanisms of wood formation, stress tolerance, tree nutrition and interaction with other organisms such as pathogens or mycorrhiza. The basis of these investigations is the reproducible production of homogeneous plant material. In this method paper we describe techniques and growth conditions for the in vitro propagation of different poplar species (Populus × canescens, P. trichocarpa, P. tremula, and P. euphratica) and ectomycorrhizal fungi (Laccaria bicolor, Paxillus involutus) as well as for their co-cultivation for ectomycorrhizal synthesis. Maintenance and plant preparation require different multiplication and rooting media. Growth systems to cultivate poplars under axenic conditions in agar and sand cultures with and without mycorrhizal fungi are described. Transfer of the plants from in vitro to in situ conditions is critical and hardening is important to prevent high mortality. Growth and vitality of the trees in vitro and outdoors with and without ectomycorrhizas are reported. PMID:23986772

  19. Fungal community associated with genetically modified poplar during metal phytoremediation.

    PubMed

    Hur, Moonsuk; Lim, Young Woon; Yu, Jae Jeong; Cheon, Se Uk; Choi, Young Im; Yoon, Seok-Hwan; Park, Sang-Cheol; Kim, Dong-Il; Yi, Hana

    2012-12-01

    Due to the increasing demand for phytoremediation, many transgenic poplars have been developed to enhance the bioremediation of heavy metals. However, structural changes to indigenous fungal communities by genetically modified organisms (GMO) presents a major ecological issue, due to the important role of fungi for plant growth in natural environments. To evaluate the effect of GM plant use on environmental fungal soil communities, extensive sequencing-based community analysis was conducted, while controlling the influence of plant clonality, plant age, soil condition, and harvesting season. The rhizosphere soils of GM and wild type (WT) poplars at a range of growth stages were sampled together with unplanted, contaminated soil, and the fungal community structures were investigated by pyrosequencing the D1/D2 region of the 28S rRNA gene. The results show that the overall structure of the rhizosphere fungal community was not significantly influenced by GM poplars. However, the presence of GM specific taxa, and faster rate of community change during poplar growth, appeared to be characteristic of the GM plant-induced effects on soil-born fungal communities. The results of this study provide additional information about the potential effects of GM poplar trees aged 1.5-3 years, on the soil fungal community. PMID:23274976

  20. Metabolic engineering and potential functions of proanthocyanidins in poplar

    PubMed Central

    Mellway, Robin D

    2009-01-01

    Poplar (Populus spp.) is a widely distributed tree genus of significant economic and ecological importance. Poplar trees accumulate proanthocyanidins (PAs) in leaves, roots, and a variety of other tissues. Damage to leaves by insects causes a rapid accumulation of PAs, both at the site of damage and distally in undamaged leaves. This rapid PA accumulation is mediated by the activation of genes encoding enzymes involved in PA synthesis. PAs have been hypothesized to deter insect feeding and reduce the nutritive value of poplar leaf tissue, but experimental evidence supporting a role for PAs as an effective inducible defense against herbivores is lacking. Our recent paper described the identification of a MYB gene that regulates the PA pathway under multiple stress conditions, and we used this gene to constitutively activate the PA pathway in poplar. Here we describe observations that suggest that poplar PAs may have roles besides insect defense, for example, responses to UV light. The PA-modified trees will be a useful tool for analyzing the biological roles of PAs in this important model tree. PMID:19820325

  1. Proteome Analysis of Poplar Seed Vigor.

    PubMed

    Zhang, Hong; Wang, Wei-Qing; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Seed vigor is a complex property that determines the seed's potential for rapid uniform emergence and subsequent growth. However, the mechanism for change in seed vigor is poorly understood. The seeds of poplar (Populus × Canadensis Moench), which are short-lived, were stored at 30 °C and 75 ± 5% relative humidity for different periods of time (0-90 days) to obtain different vigor seeds (from 95 to 0% germination). With decreasing seed vigor, the temperature range of seed germination became narrower; the respiration rate of the seeds decreased markedly, while the relative electrolyte leakage increased markedly, both levelling off after 45 days. A total of 81 protein spots showed a significant change in abundance (≥ 1.5-fold, P < 0.05) when comparing the proteomes among seeds with different vigor. Of the identified 65 proteins, most belonged to the groups involved in metabolism (23%), protein synthesis and destination (22%), energy (18%), cell defense and rescue (17%), and storage protein (15%). These proteins accounted for 95% of all the identified proteins. During seed aging, 53 and 6 identified proteins consistently increased and decreased in abundance, respectively, and they were associated with metabolism (22%), protein synthesis and destination (22%), energy (19%), cell defense and rescue (19%), storage proteins (15%), and cell growth and structure (3%). These data show that the decrease in seed vigor (aging) is an energy-dependent process, which requires protein synthesis and degradation as well as cellular defense and rescue. PMID:26172265

  2. Insect regurgitant and wounding elicit similar defense responses in poplar leaves: not something to spit at?

    PubMed

    Major, Ian T; Constabel, C Peter

    2007-01-01

    How plants perceive insect attacks is an area of active research. Numerous studies have shown that regurgitant from feeding insects elicits a defense response in plants, which is often assumed to be distinct from a wound response. We have characterized the inducible defense response in hybrid poplar and found it to be qualitatively similar between wounding and application of regurgitant from forest tent caterpillar. We suggest that this is likely attributable to our wounding treatment which is much more intense compared to most other studies. These overlapping responses appear to be activated via jasmonic acid signaling, and we speculate that they are both triggered by elicitors of plant origin. Wounding would release such elicitor molecules when leaf cells are disrupted, and regurgitant may contain them in a modified or processed form. This hypothesis could explain why some other necrosis-inducing stresses also induce herbivore defense genes. PMID:19704794

  3. Cinnamyl Alcohol Dehydrogenase: Identification of New Sites of Promoter Activity in Transgenic Poplar.

    PubMed Central

    Hawkins, S.; Samaj, J.; Lauvergeat, V.; Boudet, A.; Grima-Pettenati, J.

    1997-01-01

    Stem sections from poplar that were stably transformed with a eucalypt cinnamyl alcohol dehydrogenase promoter-[beta]-glucuronidase construct were prepared by using either a technique routinely used in herbaceous species or a technique designed to take into account the particular anatomy of woody plants. Although both preparation techniques confirmed the pattern of expression previously observed (C. Feuillet, V. Lauvergeat, C. Deswarte, G. Pilate, A. Boudet and J. Grima-Pettenati [1995] Plant Mol Biol 27: 651-657), the latter technique also allowed the detection of other sites of promoter activity not revealed by the first technique. In situ hybridization confirmed the expression pattern obtained with the second sample preparation technique. PMID:12223610

  4. Decreased transpiration in poplar trees exposed to 2,4,6-trinitrotoluene

    SciTech Connect

    Thompson, P.L.; Ramer, L.A.; Guffey, A.P.; Schnoor, J.L.

    1998-01-01

    The improper handling of the toxic compound 2,4,6-trinitrotoluene (TNT) has led to the contamination of soil and groundwater, and the uptake of TNT by a variety of plants has been established. This article discusses the effects of various concentrations of the explosive 2,4,6-trinitrotoluene (TNT) on the transpiration of hybrid poplar trees growing in hydroponic media. Transpiration was measured daily by gravimetric means. The rapid removal of TNT from hydroponic solutions was a result of plant uptake and required a daily dosage of TNT to ensure a relatively constant exposure over time. Transpiration decreased with increasing TNT concentrations {ge}5 mg/L. Decreases in transpiration were accompanied by leaf chlorosis and abscission. A comparison between a laboratory study and a pilot-scale experiment showed good scale-up potential.

  5. Genomic insights into salt adaptation in a desert poplar

    SciTech Connect

    Ma, Tao; Wang, Junyi; Zhou, Gongke; Yue, Zhen; Hu, Quanjun; Chen, Yan; Liu, Bingbing; Qiu, Qiang; Wang, Zhuo; Zhang, Jian; Wang, Kun; Jaing, Dechun; Gou, Caiyun; Yu, Lili; Zhan, Dongliang; Zhou, Ran; Luo, Wenchun; Ma, Hui; Yang, Yongzhi; Pan, Shengkai; Fang, Dongming; Luo, Yadan; Wang, Xia; Wang, Gaini; Wang, Juan; Wang, Qian; Lu, Xu; Chen, Zhe; Liu, Jinchao; Lu, Yao; Yin, Ye; Yang, Huanming; Abbott, Richard; Wu, Yuxia; Wan, Dongshi; Li, Jia; Yin, Tongming; Yin, Tongming; Lascoux, Martin; DiFazio, Steven P; Tuskan, Gerald A; Wang, Jun; Jianquan, Liu

    2013-01-01

    Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to sa lt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.

  6. 77 FR 64955 - Hardwood and Decorative Plywood From the People's Republic of China: Initiation of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Hardwood and Decorative Plywood From the People's Republic of China: Initiation of Countervailing Duty Investigation AGENCY: Import Administration, International Trade Administration, Department of Commerce....

  7. 78 FR 58283 - Hardwood and Decorative Plywood from the People's Republic of China: Final Affirmative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-23

    ...The Department of Commerce (the Department) determines that countervailable subsidies are being provided to producers and/or exporters of hardwood and decorative plywood From the People's Republic of China...

  8. Seeing the Forage and the Trees: Scale and Spatial Heterogeneity in Mixed Hardwood Silvopastoral Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silvopastoral management attempts to optimize the biophysical interactions between pasture grasses, trees, and grazing animals to increase the productivity, efficiency, and sustainability of the entire system. Determining how best to space and thin trees within mixed hardwood silvopastures to provi...

  9. AmeriFlux US-Wi8 Young hardwood clearcut (YHW)

    SciTech Connect

    Chen, Jiquan

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Wi8 Young hardwood clearcut (YHW). Site Description - The Wisconsin Clearcut Young Hardwood site is located in the Washburn Ranger District of the northeastern section of Chequamegon National Forest. A member of the northern coniferous-deciduous biome, surveys from the mid-19th century indicate the region consisted of a mixed stand of red, white, and jack pines. After extensive timber harvesting, wildfires, and farming activity, the region turned into a fragmented mosaic of stands of various ages and composition. The young hardwood clearcut site is one of ten sites that collectively represent the successional stages of development in the predominant stand types of a physically homogeneous landscape. In 2001, northern hardwood stands of all ages occupied 45% of the region.

  10. MANAGEMENT OF BOTTOMLAND HARDWOODS AND DEEPWATER SWAMPS FOR THREATENED AND ENDANGERED SPECIES.

    EPA Science Inventory

    Bottomland hardwood forests (BLH) and deepwater swamps on military installations support multiple uses beyond Department of Defense (DoD) training and testing missions, including threatened and endangered species (TES) conservation, public recreation, and forest commodities produ...

  11. 76 FR 28308 - Modification of Class E Airspace; Poplar, MT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-17

    ... proposed rulemaking to establish additional controlled airspace at Poplar, MT (76 FR 8921). Interested... Executive Order 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR... U.S.C. 106(g), 40103, 40113, 40120; E. O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec....

  12. Wood reinforcement of poplar by rice NAC transcription factor.

    PubMed

    Sakamoto, Shingo; Takata, Naoki; Oshima, Yoshimi; Yoshida, Kouki; Taniguchi, Toru; Mitsuda, Nobutaka

    2016-01-01

    Lignocellulose, composed of cellulose, hemicellulose, and lignin, in the secondary cell wall constitutes wood and is the most abundant form of biomass on Earth. Enhancement of wood accumulation may be an effective strategy to increase biomass as well as wood strength, but currently only limited research has been undertaken. Here, we demonstrated that OsSWN1, the orthologue of the rice NAC Secondary-wall Thickening factor (NST) transcription factor, effectively enhanced secondary cell wall formation in the Arabidopsis inflorescence stem and poplar (Populus tremula×Populus tremuloides) stem when expressed by the Arabidopsis NST3 promoter. Interestingly, in transgenic Arabidopsis and poplar, ectopic secondary cell wall deposition in the pith area was observed in addition to densification of the secondary cell wall in fiber cells. The cell wall content or density of the stem increased on average by up to 38% and 39% in Arabidopsis and poplar, respectively, without causing growth inhibition. As a result, physical strength of the stem increased by up to 57% in poplar. Collectively, these data suggest that the reinforcement of wood by NST3pro:OsSWN1 is a promising strategy to enhance wood-biomass production in dicotyledonous plant species. PMID:26812961

  13. Wood reinforcement of poplar by rice NAC transcription factor

    PubMed Central

    Sakamoto, Shingo; Takata, Naoki; Oshima, Yoshimi; Yoshida, Kouki; Taniguchi, Toru; Mitsuda, Nobutaka

    2016-01-01

    Lignocellulose, composed of cellulose, hemicellulose, and lignin, in the secondary cell wall constitutes wood and is the most abundant form of biomass on Earth. Enhancement of wood accumulation may be an effective strategy to increase biomass as well as wood strength, but currently only limited research has been undertaken. Here, we demonstrated that OsSWN1, the orthologue of the rice NAC Secondary-wall Thickening factor (NST) transcription factor, effectively enhanced secondary cell wall formation in the Arabidopsis inflorescence stem and poplar (Populus tremula×Populus tremuloides) stem when expressed by the Arabidopsis NST3 promoter. Interestingly, in transgenic Arabidopsis and poplar, ectopic secondary cell wall deposition in the pith area was observed in addition to densification of the secondary cell wall in fiber cells. The cell wall content or density of the stem increased on average by up to 38% and 39% in Arabidopsis and poplar, respectively, without causing growth inhibition. As a result, physical strength of the stem increased by up to 57% in poplar. Collectively, these data suggest that the reinforcement of wood by NST3pro:OsSWN1 is a promising strategy to enhance wood-biomass production in dicotyledonous plant species. PMID:26812961

  14. Denitrification in bottomland hardwood wetland soils of the Cache River

    USGS Publications Warehouse

    DeLaune, R.D.; Boar, R.R.; Lindau, C.W.; Kleiss, B.A.

    1996-01-01

    Denitrification rates were quantified in bottomland hardwood wetland soils of the Cache River. N15 labeled nitrate was added to columns containing wetland soils and river water. Over 40 days, nitrate-N in floodwater (approximately 9 mg N L-1) decreased by between 82% and 59%, which gave estimates of N export from the water column of between 11.5 mg N m-2 day-1 and 7.5 mg N m-2 day-1. These values correlated directly with organic content of surface sediment, which included forest litter. Added glucose doubled rates of nitrate loss in these soils, which indicated that the process was carbon limited. Nitrification occurring simultaneously with denitrification was determined using isotopic dilution techniques. Contributions of nitrate to water from nitrification were estimated at between 5% and 12% of the total nitrate reduced. Rates of nitrogen transformation in these forest soils were likely limited by available soil carbon from tree litter and perhaps canopy leachate, rather than by nitrate concentration in inflowing floodwater.

  15. Hardwood biochar influences calcareous soil physicochemical and microbiological status.

    PubMed

    Ippolito, J A; Stromberger, M E; Lentz, R D; Dungan, R S

    2014-03-01

    The effects of biochar application to calcareous soils are not well documented. In a laboratory incubation study, a hardwood-based, fast pyrolysis biochar was applied (0, 1, 2, and 10% by weight) to a calcareous soil. Changes in soil chemistry, water content, microbial respiration, and microbial community structure were monitored over a 12-mo period. Increasing the biochar application rate increased the water-holding capacity of the soil-biochar blend, a trait that could be beneficial under water-limited situations. Biochar application also caused an increase in plant-available Fe and Mn, soil C content, soil respiration rates, and bacterial populations and a decrease in soil NO-N concentration. Biochar rates of 2 and 10% altered the relative proportions of bacterial and fungal fatty acids and shifted the microbial community toward greater relative amounts of bacteria and fewer fungi. The ratio of fatty acid 19:0 cy to its precursor, 18:1ω7c, was higher in the 10% biochar rate soil than in all other soils, potentially indicating an environmental stress response. The 10% application rate of this particular biochar was extreme, causing the greatest change in microbial community structure, a physiological response to stress in Gram-negative bacteria, and a drastic reduction in soil NO-N (85-97% reduction compared with the control), all of which were sustained over time. PMID:25602669

  16. Breeding biology of Acadian flycatchers in a bottomland hardwood forest

    USGS Publications Warehouse

    Wilson, R.R.; Cooper, R.J.

    1998-01-01

    From 1993-1995, we located and monitored 601 Acadian Flycatcher (Empidonax virescens) nests in a large contiguous tract of bottomland hardwood forest on the White River National Wildlife Refuge, Arkansas. Annual reproductive success was significantly different among years; ranging from 10-25% (Mayfield estimate) over the three years of the study. There was no significant difference in nest success among study plots, with nesting success showing a trend of increasing late in the breeding season. Clutch size for non-parasitized nests averaged 2.9 ? 0.02 (SE) eggs with a mode of 3. Rates of Brown-headed Cowbird (Molothrus ater) parasitism were low (21%), accounting for 7% of all nest failures. However, parasitism by cowbirds resulted in a reduction of clutch size for nests initiated early (i.e., first nests and replacements) in the breeding season. Predation was the leading cause of nest failures, accounting for 75% of all failures. Snakes and avian predators were thought to be the leading cause of nest failures. Although additional factors must be investigated, preliminary results indicate that nest predation is a major influence on this population, despite the size of the forest tract.

  17. Sulfate Metabolites of 4-Monochlorobiphenyl in Whole Poplar Plants

    PubMed Central

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2013-01-01

    4-Monochlorobiphenyl (PCB3) has been proven to be transformed into hydroxylated metabolites of PCB3 (OH-PCB3s) in whole poplar plants in our previous work. However, hydroxylated metabolites of PCBs, including OH-PCB3s, as the substrates of sulfotransferases have not been studied in many organisms including plants in vivo. Poplar (Populus deltoides × nigra, DN34) was used to investigate the further metabolism from OH-PCB3s to PCB3 sulfates because it is a model plant and one that is frequently utilized in phytoremediation. Results showed poplar plants could metabolize PCB3 into PCB3 sulfates during 25 day exposures. Three sulfate metabolites, including 2′-PCB3 sulfate, 3′-PCB3 sulfate and 4′-PCB3 sulfate, were identified in poplar roots and their concentrations increased in the roots from day 10 to day 25. The major products were 2′-PCB3 sulfate and 4′-PCB3 sulfate. However, the concentrations of PCB3 sulfates were much lower than those of OH-PCB3s in the roots, suggesting the sequential transformation of these hydroxylated PCB3 metabolites into PCB3 sulfates in whole poplars. In addition, 2′-PCB3 sulfate or 4′-PCB3 sulfate was also found in the bottom wood samples indicating some translocation or metabolism in woody tissue. Results suggested that OH-PCB3s were the substrates of sulfotransferases which catalyzed the formation of PCB3 sulfates in the metabolic pathway of PCB3. PMID:23215248

  18. Synopsis of wetland functions and values: bottomland hardwoods with special emphasis on eastern Texas and Oklahoma

    USGS Publications Warehouse

    Wilkinson, D.L.; Schneller-McDonald, K.; Olson, R.W.; Auble, G.T.

    1987-01-01

    Bottomland hardwood wetlands are the natural cover type of many floodplain ecosystems in the southeastern United States. They are dynamic, productive systems that depend on intermittent flooding and moving water for maintenance of structure and function. Many of the diverse functions performed by bottomland hardwoods (e.g., flood control, sediment trapping, fish and wildlife habitat) are directly or indirectly valued by humans. Balanced decisions regarding bottomland hardwoods are often hindered by a limited ability to accurately specify the functions being performed by these systems and, furthermore, by an inability to evaluate these functions in economic terms. This report addresses these informational needs. It focuses on the bottomland hardwoods of eastern Texas and Oklahoma, serving as an introduction and entry to the literature. It is not intended to serve as a substitute for reference to the original literature. The first section of the report is a review of the major functions of bottomland hardwoods, grouped under the headings of hydrology, water quality, productivity, detritus, nutrients, and habitat. Although the hydrology of these areas is diverse and complex, especially with respect to groundwater, water storage at high flows can clearly function to attenuate peak flows, with possible reductions in downstream flooding damage. Water moving through a bottomland hardwood system carries with it various organic and inorganic constituents, including sediment, organic matter, nutrients, and pollutants. When waterborne materials are introduced to bottomland hardwoods (from river flooding or upland runoff), they may be retained, transformed, or transported. As a result, water quality may be significantly altered and improved. The fluctuating and flowing water regime of bottomland hardwoods is associated with generally high net primary productivity and rapid fluxes of organic matter and nutrients. These, in turn, support secondary productivity in the bottomland

  19. Functional Characterization and Subcellular Localization of Poplar (Populus trichocarpa × Populus deltoides) Cinnamate 4-Hydroxylase1

    PubMed Central

    Ro, Dae Kyun; Mah, Nancy; Ellis, Brian E.; Douglas, Carl J.

    2001-01-01

    Cinnamic acid 4-hydroxylase (C4H), a member of the cytochrome P450 monooxygenase superfamily, plays a central role in phenylpropanoid metabolism and lignin biosynthesis and possibly anchors a phenylpropanoid enzyme complex to the endoplasmic reticulum (ER). A full-length cDNA encoding C4H was isolated from a hybrid poplar (Populus trichocarpa × P. deltoides) young leaf cDNA library. RNA-blot analysis detected C4H transcripts in all organs tested, but the gene was most highly expressed in developing xylem. C4H expression was also strongly induced by elicitor-treatment in poplar cell cultures. To verify the catalytic activity of the putative C4H cDNA, two constructs, C4H and C4H fused to the FLAG epitope (C4H::FLAG), were expressed in yeast. Immunoblot analysis showed that C4H was present in the microsomal fraction and microsomal preparations from strains expressing both enzymes efficiently converted cinnamic acid to p-coumaric acid with high specific activities. To investigate the subcellular localization of C4H in vivo, a chimeric C4H-green fluorescent protein (GFP) gene was engineered and stably expressed in Arabidopsis. Confocal laser microscopy analysis clearly showed that in Arabidopsis the C4H::GFP chimeric enzyme was localized to the ER. When expressed in yeast, the C4H::GFP fusion enzyme was also active but displayed significantly lower specific activity than either C4H or C4H::FLAG in in vitro and in vivo enzyme assays. These data definitively show that C4H is localized to the ER in planta. PMID:11351095

  20. Comparative water use by maize, perennial crops, restored prairie, and poplar trees in the US Midwest

    NASA Astrophysics Data System (ADS)

    Hamilton, S. K.; Hussain, M. Z.; Bhardwaj, A. K.; Basso, B.; Robertson, G. P.

    2015-06-01

    Water use by plant communities across years of varying water availability indicates how terrestrial water balances will respond to climate change and variability as well as to land cover change. Perennial biofuel crops, likely grown mainly on marginal lands of limited water availability, provide an example of a potentially extensive future land cover conversion. We measured growing-season evapotranspiration (ET) based on daily changes in soil profile water contents in five perennial systems—switchgrass, miscanthus, native grasses, restored prairie, and hybrid poplar—and in annual maize (corn) in a temperate humid climate (Michigan, USA). Three study years (2010, 2011 and 2013) had normal growing-season rainfall (480-610 mm) whereas 2012 was a drought year (210 mm). Over all four years, mean (±SEM) growing-season ET for perennial systems did not greatly differ from corn (496 ± 21 mm), averaging 559 (±14), 458 (±31), 573 (±37), 519 (±30), and 492 (±58) mm for switchgrass, miscanthus, native grasses, prairie, and poplar, respectively. Differences in biomass production largely determined variation in water use efficiency (WUE). Miscanthus had the highest WUE in both normal and drought years (52-67 and 43 kg dry biomass ha-1 mm-1, respectively), followed by maize (40-59 and 29 kg ha-1 mm-1) the native grasses and prairie were lower and poplar was intermediate. That measured water use by perennial systems was similar to maize across normal and drought years contrasts with earlier modeling studies and suggests that rain-fed perennial biomass crops in this climate have little impact on landscape water balances, whether replacing rain-fed maize on arable lands or successional vegetation on marginal lands. Results also suggest that crop ET rates, and thus groundwater recharge, streamflow, and lake levels, may be less sensitive to climate change than has been assumed.

  1. [Professional exposure to hardwood dusts in a group of Sicilian joiners].

    PubMed

    Lacca, G; Provenzani, A; Mangiapane, N; Verso, M G; Picciotto, D

    2007-01-01

    Wood is a system of vegetable tissues chemically formed by biopolymers (90-99%) and phenolic substances, alkaloids, glucosides and saponins (1-10%). There are two botanical groups of wood: hardwood and softwood. Aim of present study was the research of possible work related diseases with professional exposure to hardwood about 25 joiners of Palermo in 2006; in fact wood dust inhalation is very dangerous for workers health because it is cancerogenous for nasal and paranasal sinus (1 IARC). We studied beech and fraxinus dusts (hardwood) and mahogany and teak dusts (exotic hardwood) in the environmental air of joiners during wood cutting and finishing touch. We also analysed exposed workers registry to know joiners duties, exposure values to wood dust, inhalatory exposure, wood type, chemical components, individual protection safety devices, environmental protection means. Then we examined workers medical case and risk histories. At the end we noticed that particle material in environmental air was regular according law reference values (D.Lgs. 66/2000: TLV-TWA 5 mg/m3); but although environmental dust values were normal, we found nasal haemorrhages in 3 workers and vasomotory headache in other 3; we also diagnosed one paranasal sinus polypus and then irritative contact dermatitis in 3 workers. So there is an answer: "can current TLV-TWA be protective and sure? And can it guarantee health of hardwood exposed workers?". PMID:18409853

  2. Hardwoods for Woody Energy Crops in the Southeast United States:Two Centuries of Practitioner Experience

    SciTech Connect

    Kline, Keith L; Coleman, Mark

    2010-01-01

    This paper summarizes opinions from forest industry experts on the potential for hardwood tree species to serve as feedstock for bioenergy in the Southeast United States. Hardwoods are of interest for bioenergy because of desirable physical qualities, genetic research advances, and growth potential. Experts observe that high productivity rates in southeastern plantations are confined to limited site conditions or require costly inputs. Eastern cottonwood and American sycamore grow quickly on rich bottomlands where they compete with higher-value crops. These species are also prone to pests and disease. Sweetgum is frost hardy, has few pest or disease problems, and grows across a broad range of sites, yet growth rates are relatively low. Eucalypts require few inputs and offer high potential productivity, but are limited by frost to the lower coastal plain and Florida. More time and investment in silviculture, selection, and breeding will be needed to develop hardwoods as competitive biofuel feedstock species. Loblolly pine has robust site requirements, growth rates rivaling hardwoods and lower costs of production. Because of existing stands and know-how, the forestry community considers loblolly pine to be a prime candidate for plantation bioenergy in the Southeast. Further research is required to study naturally regenerated hardwood biomass resources.

  3. Genome Enabled Discovery of Carbon Sequestration Genes in Poplar

    SciTech Connect

    Filichkin, Sergei; Etherington, Elizabeth; Ma, Caiping; Strauss, Steve

    2007-02-22

    The goals of the S.H. Strauss laboratory portion of 'Genome-enabled discovery of carbon sequestration genes in poplar' are (1) to explore the functions of candidate genes using Populus transformation by inserting genes provided by Oakridge National Laboratory (ORNL) and the University of Florida (UF) into poplar; (2) to expand the poplar transformation toolkit by developing transformation methods for important genotypes; and (3) to allow induced expression, and efficient gene suppression, in roots and other tissues. As part of the transformation improvement effort, OSU developed transformation protocols for Populus trichocarpa 'Nisqually-1' clone and an early flowering P. alba clone, 6K10. Complete descriptions of the transformation systems were published (Ma et. al. 2004, Meilan et. al 2004). Twenty-one 'Nisqually-1' and 622 6K10 transgenic plants were generated. To identify root predominant promoters, a set of three promoters were tested for their tissue-specific expression patterns in poplar and in Arabidopsis as a model system. A novel gene, ET304, was identified by analyzing a collection of poplar enhancer trap lines generated at OSU (Filichkin et. al 2006a, 2006b). Other promoters include the pGgMT1 root-predominant promoter from Casuarina glauca and the pAtPIN2 promoter from Arabidopsis root specific PIN2 gene. OSU tested two induction systems, alcohol- and estrogen-inducible, in multiple poplar transgenics. Ethanol proved to be the more efficient when tested in tissue culture and greenhouse conditions. Two estrogen-inducible systems were evaluated in transgenic Populus, neither of which functioned reliably in tissue culture conditions. GATEWAY-compatible plant binary vectors were designed to compare the silencing efficiency of homologous (direct) RNAi vs. heterologous (transitive) RNAi inverted repeats. A set of genes was targeted for post transcriptional silencing in the model Arabidopsis system; these include the floral meristem identity gene (APETALA1 or

  4. Sodium sulfite-formaldehyde pretreatment of mixed hardwoods and its effect on enzymatic hydrolysis.

    PubMed

    Jin, Yongcan; Yang, Linfeng; Jameel, Hasan; Chang, Hou-min; Phillips, Richard

    2013-05-01

    In this work, mixed hardwoods were pretreated by sodium sulfite-formaldehyde (SF). The effects of SF pretreatment on the chemical compositions and enzymatic hydrolysis of mixed hardwoods were investigated. SF pretreatment temperature had a significant effect on pulp yield and delignification, resulting in an increased efficiency of enzymatic hydrolysis. After 96 h of enzymatic hydrolysis at the cellulase loading of 40 FPU/g substrate, the yields of glucan and xylan on the basis of original wood were 37% and 11% for the pulp produced with 12% sulfite charge at 170 °C for 2 h. The total sugar recovery based on the sugar in original wood was 74%. These results indicate that sulfite-formaldehyde cooking is of great potential to be a pretreatment method for a greenfield mill to produce fuel ethanol from hardwood. PMID:23127844

  5. Uneven-aged management of pine and pine-hardwood mixtures in the Ouachita mountains

    SciTech Connect

    Shelton, M.G.; Baker, J.B.

    1992-01-01

    The Ouachita National Forest and the Southern Forest Experiment Station launched a long-term research project in 1988 to study uneven-aged management of shortleaf pine and pine-hardwood mixtures in the Ouachita Mountains. The successful use of uneven-aged management in the southern pines has to date been limited to pure stands. However, the maintenance of a hardwood component is desirable to enhance biological diversity, wildlife habitat, and aesthetics. The study's goals are: (1) to determine the levels at which pine and hardwoods are biologically compatible in uneven-aged stands, and (2) to evaluate the timber, wildlife, water quality, aesthetics and biodiversity associated with each management alternative so that sound decisions concerning the tradeoffs among these resources can be determined.

  6. Effect of Continuous Cropping Generations on Each Component Biomass of Poplar Seedlings during Different Growth Periods

    PubMed Central

    Xia, Jiangbao; Zhang, Shuyong; Li, Tian; Liu, Xia; Zhang, Ronghua; Zhang, Guangcan

    2014-01-01

    In order to investigate the change rules and response characteristics of growth status on each component of poplar seedling followed by continuous cropping generations and growth period, we clear the biomass distribution pattern of poplar seedling, adapt continuous cropping, and provide theoretical foundation and technical reference on cultivation management of poplar seedling, the first generation, second generation, and third generation continuous cropping poplar seedlings were taken as study objects, and the whole poplar seedling was harvested to measure and analyze the change of each component biomass on different growth period poplar leaves, newly emerging branches, trunks and root system, and so forth. The results showed that the whole biomass of poplar seedling decreased significantly with the leaf area and its ratio increased, and the growth was inhibited obviously. The biomass aboveground was more than that underground. The ratios of leaf biomass and newly emerging branches biomass of first continuous cropping poplar seedling were relatively high. With the continuous cropping generations and growth cycle increasing, poplar seedling had a growth strategy to improve the ratio of root-shoot and root-leaf to adapt the limited soil nutrient of continuous cropping. PMID:25401150

  7. Nitrogen ion utilization by tulip poplar (Liriodendron tulipifera L. ) seedlings

    SciTech Connect

    Mann, L.K.

    1982-01-01

    Growth responses of one-year-old tulip poplar seedlings were determined for different nitrogen sources (HN/sub 4/NO/sub 3/, NH+/sub 4/, NO-/sub 3/, no nitrogen) at 336 ppm N in nutrient culture. At the end of three months, there were no significant differences in growth observed among treatments in terms of stem elongation, leaf area, and leaf size. After four months, however, seedlings of the NH/sub 4/NO/sub 3/ treatment exhibited significantly (P<0.05) greater growth (final weight gain and stem elongation) than all other nitrogen sorces. Growth was slightly less for the NO-/sub 3/ treatment plants, but compared with NH+/sub 4/ and no nitrogen treatment, both NH/sub 4/NO/sub 3/ and NO-/sub 3/ treatments exhibited significantly greater growth responses. NO-/sub 3/ is recommended as the sole nitrogen source, especially for small seedlings of tulip poplar.

  8. Poplar lignin decomposition by gram-negative aerobic bacteria

    SciTech Connect

    Odier, E.; Janin, G.; Monties, B.

    1981-02-01

    Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood sections. No degradation of wood polysaccharides was detected. Lignin biodegradation by Pseudomonas 106 was confirmed by 14CO2 release from labeled poplar wood, although in lower yields compared with results obtained through chemical analysis based on acetyl bromide residual lignin determination. (Refs. 31).

  9. Fall 1993 Hardwood Seed Collection Project for the Savannah River Site

    SciTech Connect

    Nelson, E.A.; Boatwright, N.I. III

    1993-12-31

    The Fall 1993 Hardwood Seed Collection Project was conducted as an initial step towards regenerating creek habitat on the Savannah River Site (SRS) that was damaged by past plant operating activities. Seed from various hardwood species was collected from the coastal plain of South Carolina (See Table 1). The contract required that seed collected from each tree be kept separate through processing and delivery. Height and dbh measurements and a photograph of each tree were also required. The contract procurement area was expanded eastward in an effort to alleviate problems associated with locating adequate seed sources in and around SRP.

  10. Impact of Biofuel Poplar Cultivation on Ground-Level Ozone and Premature Human Mortality Depends on Cultivar Selection and Planting Location.

    PubMed

    Ashworth, Kirsti; Wild, Oliver; Eller, Allyson S D; Hewitt, C Nick

    2015-07-21

    Isoprene and other volatile organic compounds emitted from vegetation play a key role in governing the formation of ground-level ozone. Emission rates of such compounds depend critically on the plant species. The cultivation of biofuel feedstocks will contribute to future land use change, altering the distribution of plant species and hence the magnitude and distribution of emissions. Here we use relationships between biomass yield and isoprene emissions derived from experimental data for 29 commercially available poplar hybrids to assess the impact that the large-scale cultivation of poplar for use as a biofuel feedstock will have on air quality, specifically ground-level ozone concentrations, in Europe. We show that the increases in ground-level ozone across Europe will increase the number of premature deaths attributable to ozone pollution each year by up to 6%. Substantial crop losses (up to ∼9 Mt y(-1) of wheat and maize) are also projected. We further demonstrate that these impacts are strongly dependent on the location of the poplar plantations, due to the prevailing meteorology, the population density, and the dominant crop type of the region. Our findings indicate the need for a concerted and centralized decision-making process that considers all aspects of future land use change in Europe, and not just the effect on greenhouse gas emissions. PMID:26098452

  11. Isoprene function in two contrasting poplars under salt and sunflecks.

    PubMed

    Behnke, K; Ghirardo, A; Janz, D; Kanawati, B; Esperschütz, J; Zimmer, I; Schmitt-Kopplin, P; Niinemets, Ü; Polle, A; Schnitzler, J P; Rosenkranz, M

    2013-06-01

    In the present study, biogenic volatile organic compound (BVOC) emissions and photosynthetic gas exchange of salt-sensitive (Populus x canescens (Aiton) Sm.) and salt-tolerant (Populus euphratica Oliv.) isoprene-emitting and non-isoprene-emitting poplars were examined under controlled high-salinity and high-temperature and -light episode ('sunfleck') treatments. Combined treatment with salt and sunflecks led to an increased isoprene emission capacity in both poplar species, although the photosynthetic performance of P. × canescens was reduced. Indeed, different allocations of isoprene precursors between the cytosol and the chloroplast in the two species were uncovered by means of (13)CO2 labeling. Populus × canescens leaves, moreover, increased their use of 'alternative' carbon (C) sources in comparison with recently fixed C for isoprene biosynthesis under salinity. Our studies show, however, that isoprene itself does not have a function in poplar survival under salt stress: the non-isoprene-emitting leaves showed only a slightly decreased photosynthetic performance compared with wild type under salt treatment. Lipid composition analysis revealed differences in the double bond index between the isoprene-emitting and non-isoprene-emitting poplars. Four clear metabolomics patterns were recognized, reflecting systemic changes in flavonoids, sterols and C fixation metabolites due to the lack/presence of isoprene and the absence/presence of salt stress. The studies were complemented by long-term temperature stress experiments, which revealed the thermotolerance role of isoprene as the non-isoprene-emitting leaves collapsed under high temperature, releasing a burst of BVOCs. Engineered plants with a low isoprene emission potential might therefore not be capable of resisting high-temperature episodes. PMID:23532135

  12. Turbulent Wind Temperature and Pressure in a Mature Hardwood Canopy.

    NASA Astrophysics Data System (ADS)

    Conklin, Paul Sheldon

    An understanding of the mechanisms controlling turbulent exchange in plant canopies is necessary for a variety of ecological, meteorological and agricultural problems. Previous studies have shown that most of the exchange is caused by intermittent, coherent, turbulence structures. This study describes these structures in a mature hardwood forest, with special attention to the role of static pressure fluctuations within and above the canopy. The study was conducted from an instrument tower in a 31 m tall forest in the piedmont region of North Carolina, USA. Measurements were made at two levels: above the forest at 1.2 times the canopy height (h), and either just below the forest canopy at 0.6 h or in the middle of the lower third of the canopy at 0.7 h. A static pressure probe consisting of two parallel, flat disks was fabricated and tested in a wind tunnel. Each measurement level included the pressure probe (p), a sonic anemometer (u v w) and a fine wire thermocouple (T). A third pressure probe was installed at the surface. Measurements from all instruments were made at five Hz and block averaged to one Hz for analysis. 22 hrs of data were analyzed. Integral time scales were calculated for each of the above variables. The relative duration of coherent signals was p > T = u > w. Lagged correlations between the measurements made above and below the canopy show that the variables were well correlated between the levels, with the order of correlation being p > w > T = u. p and w measurements were synchronous at all measurement heights, while T below the canopy lagged T above, and u showed both lags and leads. The segments of the data showing turbulent structures were ensemble averaged for a variety of atmospheric stability conditions. These averages show that a vertically synchronous pressure pulse accompanies each turbulent structure. Two flow regimes are demonstrated for u, one driven by advected momentum and one driven by pressure gradients. Vertical velocity

  13. Modeling sustainable reuse of nitrogen-laden wastewater by poplar.

    PubMed

    Wang, Yusong; Licht, Louis; Just, Craig

    2016-06-01

    Numerical modeling was used to simulate the leaching of nitrogen (N) to groundwater as a consequence of irrigating food processing wastewater onto grass and poplar under various management scenarios. Under current management practices for a large food processor, a simulated annual N loading of 540 kg ha(-1) yielded 93 kg ha(-1) of N leaching for grass and no N leaching for poplar during the growing season. Increasing the annual growing season N loading to approximately 1,550 kg ha(-1) for poplar only, using "weekly", "daily" and "calculated" irrigation scenarios, yielded N leaching of 17 kg ha(-1), 6 kg ha(-1), and 4 kg ha(-1), respectively. Constraining the simulated irrigation schedule by the current onsite wastewater storage capacity of approximately 757 megaliters (Ml) yielded N leaching of 146 kg ha(-1) yr(-1) while storage capacity scenarios of 3,024 and 4,536 Ml yielded N leaching of 65 and 13 kg ha(-1) yr(-1), respectively, for a loading of 1,550 kg ha(-1) yr(-1). Further constraining the model by the current wastewater storage volume and the available land area (approximately 1,000 hectares) required a "diverse" irrigation schedule that was predicted to leach a weighted average of 13 kg-N ha(-1) yr(-1) when dosed with 1,063 kg-N ha(-1) yr(-1). PMID:26375195

  14. Systematic functional genomics resource and annotation for poplar.

    PubMed

    Si, Jingna; Zhao, Xiyang; Zhao, Xinyin; Wu, Rongling

    2015-08-01

    Poplar, as a model species for forestry research, has many excellent characteristics. Studies on functional genes have provided the foundation, at the molecular level, for improving genetic traits and cultivating elite lines. Although studies on functional genes have been performed for many years, large amounts of experimental data remain scattered across various reports and have not been unified via comprehensive statistical analysis. This problem can be addressed by employing bioinformatic methodology and technology to gather and organise data to construct a Poplar Functional Gene Database, containing data on 207 poplar functional genes. As an example, the authors investigated genes of Populus euphratica involved in the response to salt stress. Four small cDNA libraries were constructed and treated with 300 mM NaCl or pure water for 6 and 24 h. Using high-throughput sequencing, they identified conserved and novel miRNAs that were differentially expressed. Target genes were next predicted and detailed functional information derived using the Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes pathway analysis. This information provides a primary visual schema allowing us to understand the dynamics of the regulatory gene network responding to salt stress in Populus. PMID:26243833

  15. Heat transfer mechanisms in poplar wood undergoing torrefaction

    NASA Astrophysics Data System (ADS)

    Sule, Idris O.; Mahmud, Shohel; Dutta, Animesh; Tasnim, Syeda Humaira

    2016-03-01

    Torrefaction, a thermal treatment process of biomass, has been proved to improve biomass combustible properties. Torrefaction is defined as a thermochemical process in reduced oxygen condition and at temperature range from 200 to 300 °C for shorter residence time whereby energy yield is maximized, can be a bridging technology that can lead the conventional system (e.g. coal-fired plants) towards a sustainable energy system. In efforts to develop a commercial operable torrefaction reactor, the present study examines the minimum input condition at which biomass is torrefied and explores the heat transfer mechanisms during torrefaction in poplar wood samples. The heat transfer through the wood sample is numerically modeled and analyzed. Each poplar wood is torrefied at temperature of 250, 270, and 300 °C. The experimental study shows that the 270 °C-treatment can be deduced as the optimal input condition for torrefaction of poplar wood. A good understanding of heat transfer mechanisms can facilitate the upscaling and downscaling of torrefaction process equipment to fit the feedstock input criteria and can help to develop treatment input specifications that can maximize process efficiency.

  16. Improving disease resistance of butternut (Juglans cinerea), a threatened fine hardwood: a case for single-tree selection through genetic improvement and deployment.

    PubMed

    Michler, Charles H; Pijut, Paula M; Jacobs, Douglass F; Meilan, Richard; Woeste, Keith E; Ostry, Michael E

    2006-01-01

    Approaches for the development of disease-resistant butternut (Juglans cinerea L.) are reviewed. Butternut is a threatened fine hardwood throughout its natural range in eastern North America because of the invasion of the exotic fungus, Sirococcus clavigignenti-juglandacearum Nair, Kostichka and Kuntz, which causes butternut canker. Early efforts were made to identify and collect putatively resistant germ plasm, identify vectors and to characterize the disease. More recently, molecular techniques have been employed to genetically characterize both the pathogen and the resistant germ plasm. Much of the host resistance may originate from hybridization with a close Asian relative, Japanese walnut (Juglans ailanthifolia Carr.), and from a few natural phenotypic variants. Further genetic characterization is needed before classical breeding or genetic modification can be used to produce canker-resistant trees. PMID:16203722

  17. EVALUATION OF COMPONENTS FOR HARDWOOD SILVOPASTORES FOR COW-CALF OPERATORS IN THE SOUTHEASTERN UNITED STATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silvopasture systems consisting of bahiagrass (Paspalum notatum) and pines (Pinus spp.) are common in the southeastern United States. However, some producers prefer other forages to bahiagrass and there are increasing opportunities for marketing hardwoods in the region. Warm season forages and hardw...

  18. 78 FR 36791 - Hardwood Plywood From China; Institution of Antidumping and Countervailing Duty Investigations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... and decorative plywood. ``Hardwood and decorative plywood is a flat panel composed of an assembly of two or more layers or plies of wood veneers in combination with a core. The veneers, along with the... plywood panel must have face and back veneers which are composed of one or more species of...

  19. STABLE SULFUR ISOTOPES OF SULFATE IN PRECIPITATION AND STREAM SOLUTIONS IN A NORTHERN HARDWOODS WATERSHED

    EPA Science Inventory

    table 5 isotopes of 5042 in precipitation and stream solutions in a northern hardwoods watershed (Bear Brooks Watershed, Maine) were examined to determine sources of stream S042- and to identify watershed processes that may affect atmospherically deposited S042 prior to reaching ...

  20. SULFUR DYNAMICS IN MINERAL HORIZONS OF TWO NORTHERN HARDWOOD SOILS A COLUMN STUDY WITH 35S

    EPA Science Inventory

    Sulfur dynamics of two Spodosols were ascertained using soil columns constructed from homogenized mineral soil from northern hardwood ecosystems at the Huntington Forest (HF) in the Adirondack Mountains of New York and Bear Brook Watershed in Maine (BBWM). olumns were leached for...

  1. Hardwood snag fragmentation in a pine-oak forest of southeastern Arkansas

    SciTech Connect

    Cain, M.D.

    1996-12-31

    Because snags are importnat for forest wildlife as breeding, roosting and foraging sites, resource managers who wish to maintain this component in forest stands need to be aware of snag fragmentation rates. Measurements were taken in uneven-aged pine-hardwood standards in southeastern Arkansas to determine fragmentation rates for hardwood snags 2 to 6 yr after stem injection with herbicides. Crown and bole condition of snags were also assessed. Pinus eschinata Mill. and P. taeda L. were the dominant overstory components and were udisturbed. Quercus spp. accounted for 91% of hardwoods greater than 25 cm dbh. Since small diameter snags deteriorated first, snag diameter distributions changed from uneven-sized to even-sized structure as time since mortality increased. Within 3 yr of injection, 57% of snag boles had broken below crown height. Number of wildlife cavities per snag increased with time since mortality. At 6 yr after injection, 44% of residual snags had evidence of wildlife cavities. Less than 50% of hardwoods less then 25 cm dbh were still standing 5 yr after herbicide injection.

  2. 78 FR 12717 - Hardwood and Decorative Plywood From the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... Plywood From the People's Republic of China: Initiation of Antidumping Duty Investigation, 77 FR 65172... Coalition for Fair Trade of Hardwood Plywood (``Petitioners''), made a timely request, pursuant to 19 CFR...'' Rule for Administrative Determination Deadlines Pursuant to the Tariff Act of 1930, As Amended, 70...

  3. 77 FR 73428 - Hardwood and Decorative Plywood From the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... FR 64955 (October 24, 2012). \\2\\ See Memorandum to the Record from Paul Piquado, Assistant Secretary... Act of 1930, As Amended, 70 FR 24533 (May 10, 2005). Postponement of Due Date for the Preliminary... investigation, the Coalition for Fair Trade of Hardwood Plywood and its individual members (Petitioners), made...

  4. Crystalliferous Bacillus cereus group bacteria from a Maryland hardwood forest are dominated by psychrotolerant strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crystal forming Bacillus spp. were isolated from soil samples collected at different elevations within a mixed hardwood forest in central Maryland, and their phylogenetic relationships determined by multilocus sequence analysis. The vast majority of isolates obtained were associated with two phylog...

  5. Tree-section harvesting of northern hardwood thinnings. Forest Service research paper

    SciTech Connect

    Mattson, J.A.

    1993-01-01

    The report describes the results of a field trial of tree-section harvesting, a shortwood version of whole-tree harvesting, in a northern hardwood thinning. This technique is technically feasible and especially useful where the appearance of the residual stand is a primary concern.

  6. Inhibition of forage seed germination by leaf litter extracts of overstory hardwoods used in silvopastoral systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silvopastoral management strategies seek to expand spatial and temporal boundaries of forage production and promote ecosystem integrity through a combination of tree thinning and understory pastures. We determined the effects of water extracts of leaf litter from yellow poplar, Liriodendron tulipife...

  7. Sulfate dry deposition to red oak and tulip poplar leaves

    SciTech Connect

    Vandenberg, J.J. ); Knoerr, K.R. )

    1988-01-01

    Measurement of rates of atmospheric sulfate dry deposition to vegetation is necessary to assess biophysical relationships. However, micrometeorological measurement techniques have stringent site and equipment requirements and direct estimation techniques have procedural and contamination difficulties. This paper describes the development and testing of a leaf washing technique to directly measure the rate of sulfate dry deposition to hardwood forest vegetation. The leaf washing technique was developed by comparing the rate of removal of sulfur dry deposited to leaf surfaces with the rate and extent of leaching from the internal sulfur pool.

  8. Trade-offs between biomass growth and inducible biosynthesis of polyhydroxybutyrate in transgenic poplar.

    PubMed

    Dalton, David A; Ma, Cathleen; Shrestha, Shreya; Kitin, Peter; Strauss, Steven H

    2011-09-01

    Polyhydroxybutyrate (PHB) is a bioplastic that can be produced in transgenic plants by the coexpression of three bacterial genes for its biosynthesis. PHB yields from plants have been constrained by the negative impacts on plant health that result from diversion of resources into PHB production; thus, we employed an ecdysone analogue-based system for induced gene expression. We characterized 49 insertion events in hybrid transgenic poplar (Populus tremula x alba) that were produced using Agrobacterium transformation and studied two high-producing events in detail. Regenerated plants contained up to 1-2% PHB (dry weight) in leaves after 6-8 weeks of induction. Strong induction was observed with 1-10 mm Intrepid and limited direct toxicity observed. Confocal fluorescence microscopy was used to visualize PHB granules in chloroplasts after chemical treatment to reduce autofluorescence. A greenhouse study indicated that there were no negative consequences of PHB production on growth unless the PHB content exceeded 1% of leaf weight; at PHB levels above 1%, growth (height, diameter and total mass) decreased by 10%-34%. PMID:21265995

  9. New hydroxylated metabolites of 4-monochlorobiphenyl in whole poplar plants

    PubMed Central

    2011-01-01

    Two new monohydroxy metabolites of 4-monochlorobiphenyl (CB3) were positively identified using three newly synthesized monohydroxy compounds of CB3: 2-hydroxy-4-chlorobiphenyl (2OH-CB3), 3-hydroxy-4-chlorobiphenyl (3OH-CB3) and 4-hydroxy-3-chlorobiphenyl (4OH-CB2). New metabolites of CB3, including 2OH-CB3 and 3OH-CB3, were confirmed in whole poplars (Populus deltoides × nigra, DN34), a model plant in the application of phytoremediation. Furthermore, the concentrations and masses of 2OH-CB3 and 3OH-CB3 formed in various tissues of whole poplar plants and controls were measured. Results showed that 2OH-CB3 was the major product in these two OH-CB3s with chlorine and hydroxyl moieties in the same phenyl ring of CB3. Masses of 2OH-CB3 and 3OH-CB3 in tissues of whole poplar plants were much higher than those in the hydroponic solution, strongly indicating that the poplar plant itself metabolizes CB3 to both 2OH-CB3 and 3OH-CB3. The total yield of 2OH-CB3 and 3OH-CB3, with chlorine and hydroxyl in the same phenyl ring of CB3, was less than that of three previously found OH-CB3s with chlorine and hydroxyl in the opposite phenyl rings of CB3 (2'OH-CB3, 3'OH-CB3, and 4'OH-CB3). Finally, these two newly detected OH-CB3s from CB3 in this work also suggests that the metabolic pathway was via epoxide intermediates. These five OH-CB3s clearly showed the complete metabolism profile from CB3 to monohydroxylated CB3. More importantly, it's the first report and confirmation of 2OH-CB3 and 3OH-CB3 (new metabolites of CB3) in a living organism. PMID:22185578

  10. ABOVEGROUND BIOMASS DISTRIBUTION OF US EASTERN HARDWOOD FORESTS AND THE USE OF LARGE TREES AS AN INDICATOR OF FOREST DEVELOPMENT

    EPA Science Inventory

    Past clearing and harvesting of the deciduous hardwood forests of eastern USA released large amount of carbon dioxide into the atmosphere, but through recovery and regrowth these forests are now accumulating atmospheric carbon (C). This study examined quantities and distribution ...

  11. Rhizosphere carbon deposition, oxidative stress and nutritional changes in two poplar species exposed to aluminum.

    PubMed

    Naik, Dhiraj; Smith, Ernest; Cumming, Jonathan R

    2009-03-01

    Species and hybrids in the genus Populus have become the focus of investigation for use in biofuels production and their capacity to sequester carbon (C) in the environment. The identification of species resistant to marginal edaphic sites may be important in both of these endeavors. Plant growth, total dissolved organic carbon (TOC) and low molecular weight organic acid (OA) production, antioxidative enzyme activities and mineral content were assessed in Populus tremuloides L. and Populus trichocarpa Torr. & Gray seedlings under exposure to aluminum (Al). Both species were sensitive to Al, with significant reductions in shoot and root biomass at and above 50 microM Al. Exposure to Al induced 40-fold increases in TOC deposition in P. tremuloides and 100-fold increases in P. trichocarpa. In P. tremuloides, Al treatment induced root exudation of malic and citric acids, while Al increased exudation of citrate and oxalate in P. trichocarpa. Organic acids accounted for 20-64% of total C released upon Al exposure, with the proportion of OAs increasing in P. tremuloides and decreasing in P. trichocarpa. Dose-dependent responses of catalase and ascorbate peroxidase were observed in both root and leaf tissues, indicating that Al exposure induced oxidative stress in poplar. Treatment at and above 100 microM Al reduced the concentrations of calcium (Ca) and magnesium (Mg) in roots and leaves, whereas Al at or above 50 microM reduced root and leaf phosphorous (P) concentrations. The majority of Al taken up was retained in the root system. Even with the induction of OA exudation and accumulation, P. tremuloides and P. trichocarpa remained sensitive to Al, as evidenced by elevated antioxidative enzyme activities, which may reflect inhibition of Ca or P uptake and destabilization of cell homeostasis in these poplar species. Although plants exhibited reductions in growth and evidence of oxidative and nutritional stress, total C rhizodeposition rates for both species increased with

  12. Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice

    NASA Astrophysics Data System (ADS)

    Sabbatini, S.; Arriga, N.; Bertolini, T.; Castaldi, S.; Chiti, T.; Consalvo, C.; Njakou Djomo, S.; Gioli, B.; Matteucci, G.; Papale, D.

    2016-01-01

    The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short-rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. This period corresponded to a single rotation of the SRC site. The REF site was a crop rotation between grassland and winter wheat, i.e. the same management of the SRC site before the conversion to short-rotation coppice. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. The measurements began 2 years after the conversion of arable land to SRC so that an older poplar plantation was used to estimate the soil organic carbon (SOC) loss due to SRC establishment and to estimate SOC recovery over time. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled. A GHG emission offset, due to the substitution of natural gas with SRC biomass, was credited to the GHG budget of the SRC site. Emissions generated by the use of biomass (FEXP) were also considered. Suitability was finally assessed by comparing the GHG budgets of the two sites. CO2 uptake was 3512 ± 224 g CO2 m-2 at the SRC site in 2 years, and 1838 ± 107 g CO2 m-2 at the REF site. FEXP was equal to 1858 ± 240 g CO2 m-2 at the REF site, thus basically compensating for FCO2, while it was 1118 ± 521 g CO2 m-2 at the SRC site. The SRC site could offset 379.7 ± 175.1 g CO2eq m-2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN made up 2 and 4 % in the GHG budgets of SRC and REF sites respectively, while the SOC loss was 455 ± 524 g CO2 m-2 in 2 years. Overall, the REF site was close to neutrality from a GHG perspective (156 ± 264 g CO2eq m-2), while the SRC site was a net sink of

  13. Greenhouse gas balance of cropland conversion to bioenergy poplar short rotation coppice

    NASA Astrophysics Data System (ADS)

    Sabbatini, S.; Arriga, N.; Bertolini, T.; Castaldi, S.; Chiti, T.; Consalvo, C.; Njakou Djomo, S.; Gioli, B.; Matteucci, G.; Papale, D.

    2015-05-01

    The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2), whereas chambers were used to measure N2O and CH4 emissions from soil. Soil organic carbon (SOC) of an older poplar plantation was used to estimate via a regression the SOC loss due to SRC establishment. Emissions from tractors and from production and transport of agricultural inputs (FMAN) were modelled and GHG emission offset due to fossil fuel substitution was credited to the SRC site considering the C intensity of natural gas. Emissions due to the use of the biomass (FEXP) were also considered. The suitability was finally assessed comparing the GHG budgets of the two sites. FCO2 was the higher flux in the SRC site (-3512 ± 224 g CO2 eq m-2 in two years), while in the REF site it was -1838 ± 107 g CO2 m-2 in two years. FEXP was equal to 1858 ± 240 g CO2 m-2 in 24 months in the REF site, thus basically compensating FCO2, while it was 1118 ± 521 g CO2 eq m-2 in 24 months in the SRC site. This latter could offset -379.7 ± 175.1 g CO2 eq m-2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN weighed 2 and 4% in the GHG budgets of SRC and REF sites respectively, while the SOC loss weighed 455 ± 524 g CO2 m-2 in two years. Overall, the REF site was close to neutrality in a GHG perspective (156 ± 264 g CO2 eq m-2), while the SRC site was a net sink of -2202 ± 792 g CO2 eq m-2. In conclusion the experiment led to a positive evaluation of the conversion of cropland to bioenergy SRC from a GHG viewpoint.

  14. Effect of drought on fine roots productivity in poplar-based short rotation coppice

    NASA Astrophysics Data System (ADS)

    Mani Tripathi, Abhishek; Fischer, Milan; Berhongaray, Gonzalo; Orság, Matěj; Trnka, Miroslav

    2015-04-01

    Short rotation woody crops (SRWC) are alternative source of bioenergy, which apart from their 'carbon neutrality' have potential to store carbon (C) into soil and mitigate the increasing CO2 emission. Studies of below ground biomass of trees are divided into two types according to root diameter - analysis of fine roots (less than 2 mm) and coarse roots (more than 2 mm). Trees roots are spatially highly heterogeneous and it requires large number of samples to obtain a representative estimate of belowground biomass. For this study we used hybrid poplar clone J-105 (Populus nigra x P. maximowiczii) grown under short rotation coppice system in the region of Bohemian-Moravian Highland (49o32'N, 16o15'E and altitude 530 m a.s.l.) since April 2000. The plantation with planting density of 9,216 trees ha-1 was established on the former agricultural land and the length of the rotation cycle was set to 6-8 years. While mean annual rainfall was 609 mm with mean annual temperature 7.2oC during 1981-2013 significant increase of temperature and more frequent droughts are expected. In 2011, we established drought experiment based on throughfall exclusion system, reducing up to 70 % of throughfall precipitation. Thus 2 treatments with normal and lowered soil moisture levels were introduced. In January and February 2014, we cored 18 places including drought and control using root bipartite auger. The main goal of the study is to assess the response of fine roots productivity and fine roots vertical distribution on the reduced soil water availability. Results will be presented at the conference. Acknowledgements: This study was funded by research project IGA Mendel University 2014 "Study of below ground biomass in short rotation poplar coppice (J-105) in the Czech-Moravian Highlands", project PASED (KONTAKT II LH12037 ʺDevelopment of models for the assessment of abiotic stresses in selected energy woody plantsʺ and "Building up a multidisciplinary scientific team focused on drought

  15. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral "Salicoid" Genome Duplication.

    PubMed

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the "salicoid" duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  16. Enhancement of Biogas Yield of Poplar Leaf by High-Solid Codigestion with Swine Manure.

    PubMed

    Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

    2016-05-01

    The aim of this work was to examine the improvement of anaerobic biodegradability of organic fractions of poplar leaf from codigestion with swine manure (SM), thus biogas yield and energy recovery. When poplar leaf was used as a sole substrate, the cumulative biogas yield was low, about 163 mL (g volatile solid (VS))(-1) after 45 days of digestion with a substrate/inoculum ratio of 2.5 and a total solid (TS) of 22 %. Under the same condition, the cumulative biogas yield of poplar leaf reached 321 mL (g VS)(-1) when SM/poplar leaf ratio was 2:5 (based on VS). The SM/poplar leaf ratio can determine C/N ratio of the cosubstrate and thus has significant influence on biogas yield. When the SM/poplar leaf ratio was 2:5, C/N ratio was calculated to be 27.02, and the biogas yield in 45 days of digestion was the highest. The semi-continuous digestion of poplar leaf was carried out with the organic loading rate of 1.25 and 1.88 g VS day(-1). The average daily biogas yield was 230.2 mL (g VS)(-1) and 208.4 mL (g VS)(-1). The composition analysis revealed that cellulose and hemicellulose contributed to the biogas production. PMID:26810922

  17. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral “Salicoid” Genome Duplication

    PubMed Central

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the “salicoid” duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  18. Characterization of top phase oil obtained from co-pyrolysis of sewage sludge and poplar sawdust.

    PubMed

    Zuo, Wu; Jin, Baosheng; Huang, Yaji; Sun, Yu

    2014-01-01

    To research the impact of adding sawdust on top phase oil, a sewage sludge and poplar sawdust co-pyrolysis experiment was performed in a fixed bed. Gas chromatography (GC)/mass spectrometry (MS) was used to analyze the component distribution of top phase oil. Higher heating value, viscosity, water content, and pH of the top phase oil product were determined. The highest top phase oil yield (5.13 wt%) was obtained from the mixture containing 15% poplar sawdust, while the highest oil yield (16.51 wt%) was obtained from 20% poplar sawdust. Top phase oil collected from the 15% mixture also has the largest amount of aliphatics and the highest higher heating value (28.6 MJ/kg). Possible reaction pathways were proposed to explain the increase in the types of phenols present in the top phase oil as the proportion of poplar sawdust used in the mixture increased. It can be concluded that synergetic reactions occurred during co-pyrolysis of sewage sludge and poplar sawdust. The results indicate that the high ash content of the sewage sludge may be responsible for the characteristic change in the top phase oil obtained from the mixtures containing different proportions of sewage sludge and poplar sawdust. Consequently, co-pyrolysis of the mixture containing 15 % poplar sawdust can increase the yield and the higher heating value of top phase oil. PMID:24756683

  19. Circadian Rhythms of Isoprene Biosynthesis in Grey Poplar Leaves1

    PubMed Central

    Loivamäki, Maaria; Louis, Sandrine; Cinege, Gyöngyi; Zimmer, Ina; Fischbach, Robert J.; Schnitzler, Jörg-Peter

    2007-01-01

    Isoprene (2-methyl-1,3-butadiene) emission varies diurnally in different species. In poplar (Populus spp.), it has recently been shown that the gene encoding the synthesizing enzyme for isoprene, isoprene synthase (ISPS), displays diurnal variation in expression. Working on shoot cultures of Grey poplar (Populus × canescens) placed under a different light regime in phytochambers, we showed that these variations in PcISPS gene expression, measured by quantitative real-time polymerase chain reaction, are not only due to day-night changes, but also are linked to an internal circadian clock. Measurement of additional selected isoprenoid genes revealed that phytoene synthase (carotenoid pathway) displays similar fluctuations, whereas 1-deoxy-d-xylulose 5-phosphate reductoisomerase, possibly the first committed enzyme of the 1-deoxy-d-xylulose 5-phosphate pathway, only shows light regulation. On the protein level, it appeared that PcISPS activity and protein content became reduced under constant darkness, whereas under constant light, activity and protein content of this enzyme were kept high. In contrast, isoprene emission rates under continuous irradiation displayed circadian changes as is the case for gene expression of PcISPS. Furthermore, binding assays with Arabidopsis (Arabidopsis thaliana) late elongated hypocotyl, a transcription factor of Arabidopsis involved in circadian regulation, clearly revealed the presence of circadian-determining regulatory elements in the promoter region of PcISPS. PMID:17122071

  20. Lignification in poplar tension wood lignified cell wall layers.

    PubMed

    Yoshinaga, Arata; Kusumoto, Hiroshi; Laurans, Françoise; Pilate, Gilles; Takabe, Keiji

    2012-09-01

    The lignification process in poplar tension wood lignified cell wall layers, specifically the S(1) and S(2) layers and the compound middle lamella (CML), was analysed using ultraviolet (UV) and transmission electron microscopy (TEM). Variations in the thickness of the gelatinous layer (G-layer) were also measured to clarify whether the lignified cell wall layers had completed their lignification before the deposition of G-layers, or, on the contrary, if lignification of these layers was still active during G-layer formation. Observations using UV microscopy and TEM indicated that both UV absorbance and the degree of potassium permanganate staining increased in the CML and S(1) and S(2) layers during G-layer formation, suggesting that the lignification of these lignified layers is still in progress during G-layer formation. In the context of the cell-autonomous monolignol synthesis hypothesis, our observations suggest that monolignols must go through the developing G-layer during the lignification of CML and the S(1) and S(2) layers. The alternative hypothesis of external synthesis (in the rays) does not require that monolignols go through the G-layer before being deposited in the CML, or the S(1) and S(2) layers. Interestingly, the previous observation of lignin in the poplar G-layer was not confirmed with the microscopy techniques used in the present study. PMID:22933655

  1. Soils organic C sequestration under poplar and willow agroforestry systems

    NASA Astrophysics Data System (ADS)

    Gunina, Anna; Tariq, Azeem; Lamersdorf, Norbert

    2015-04-01

    Short rotation coppices (SRC) as monocultures or as agroforestry (AF) applications (e.g. alley cropping) are two techniques to implement forest into agricultural practices. Despite afforestation promotes soil carbon (C) accumulation, age and type of the tree stand can affect the C accumulation in different degrees. Here, we studied the impact of afforestation on C accumulation for: i) pure SCR of willow (Salix viminalis x Salix schwerinii) and poplar (Populus nigra x Populus maximowiczii) and ii) AF cropping system with willow. Forest systems have been established within the BEST agroforestry project in Germany. Adjacent agricultural field have been used as a control. Soil samples were collected in 2014, three years after plantation establishment, from three soil depths: 0-3, 3-20, and 20-30 cm. Total organic C, labile C (incubation of 20 g soil during 100 days with measuring of CO2) and aggregate structure were analysed. Additionally, density fractionation of the samples from 0-3 cm was applied to separate particulate organic matter (POM) and mineral fractions. Aggregates and density fractions were analyzed for C content. High input of plant litter as well as root exudates have led to increases of organic C in AF and SRC plots compare to cropland, mainly in the top 0-3 cm. The highest C content was found for willow SRC (18.2 g kg-1 soil), followed by willow-AF (15.6 g kg-1 soil), and poplar SRC (13.7 g kg-1 soil). Carbon content of cropland was 12.5 g kg-1 soil. Absence of ploughing caused increase portion of macroaggregates (>2000 μm) under SRC and AF in all soil layers as well as the highest percentage of C in that aggregate size class (70-80%). In contrast, C in cropland soil was mainly accumulated in small macroaggregates (250-2000 μm). Intensive mineralisation of fresh litter and old POM, taking place during first years of trees development, resulted to similar portions of free POM for willow AF, willow SRC and cropland (8%), and even lower ones for poplar

  2. Ecology of bottomland hardwood swamps of the southeast: a community profile

    SciTech Connect

    Wharton, C.H.; Kitchens, W.M.; Pendleton, E.C.; Sipe, T.W.

    1982-03-01

    This report synthesizes extant literature detailing the ecology of bottomland hardwood swamps in the Southeast. The geographic scope focuses the report to the hardwoods occupying the floodplains of the rivers whose drainages originate in the Appalachian Mountains/Piedmont and Coastal Plain (NC, SC, GA, and FL). The origin and dynamics of the floodplains are described and related to hydrology and physiographic provinces. Further, the biogeochemistry and interactions between the riverine and floodplain environments are discussed in conjunction with floodplain biology. Plant and animal community structure and ecological processes (productivity) are detailed and organized by ecological zones. The final chapter discusses the ecological value of the floodplain ecosystems and the nature of their relationships to adjacent uplands, downstream coastal estuaries and the atmosphere.

  3. Co-gasification of hardwood chips and crude glycerol in a pilot scale downdraft gasifier.

    PubMed

    Wei, Lin; Pordesimo, Lester O; Haryanto, Agus; Wooten, James

    2011-05-01

    Seeking appropriate approaches to utilize the crude glycerol produced in biodiesel production is very important for the economic viability and environmental impacts of biodiesel industry. Gasification may be one of options for addressing this issue. Co-gasification of hardwood chips blending with crude glycerol in various loading levels was undertaken in the study involving a pilot scale fixed-bed downdraft gasifier. The results indicated that crude glycerol loading levels affected the gasifier's performance and the quality of syngas produced. When crude glycerol loading level increased, the CO, CH(4), and tar concentrations of the syngas also increased but particle concentration decreased. Though further testing is suggested, downdraft gasifiers could be run well with hardwood chips blending with liquid crude glycerol up to 20 (wt%). The syngas produced had relatively good quality for fueling internal combustion engines. This study provides a considerable way to utilize crude glycerol. PMID:21435871

  4. Bottomland hardwood restoration in the Mississippi Alluvial Valley: Looking past the trees to see the forest

    USGS Publications Warehouse

    Wilson, R.R.; Oliver, J.M.; Twedt, D.J.; Uihlein, W.B., III

    2005-01-01

    Planned restoration of bottomland hardwoods is important to adequately address negative consequences resulting from the severe loss and fragmentation of forested wetlands in the Mississippi Alluvial Valley. Reforestation efforts have been promoted through government initiatives of state and federal agencies (e.g. Wetland Reserve Program) and private conservation groups. To clarify discussions of forested wetland restoration, we offer definitions of reforestation and restoration, review historic reforestation practices, identify additional needs, and propose a conceptual framework to assist in future reforestation efforts. Future reforestation efforts should include: (1) comprehensive planning among participating agencies, (2) standardized documentation of methods, and (3) short-term and long-term monitoring protocols that permit refinement of methodologies. Implementation of these concepts will promote cooperative planning among participants and facilitate research to evaluate bottomland hardwood restoration efforts.

  5. Computer Vision System For Locating And Identifying Defects In Hardwood Lumber

    NASA Astrophysics Data System (ADS)

    Conners, Richard W.; Ng, Chong T.; Cho, Tai-Hoon; McMillin, Charles W.

    1989-03-01

    This paper describes research aimed at developing an automatic cutup system for use in the rough mills of the hardwood furniture and fixture industry. In particular, this paper describes attempts to create the vision system that will power this automatic cutup system. There are a number of factors that make the development of such a vision system a challenge. First there is the innate variability of the wood material itself. No two species look exactly the same, in fact, they can have a significant visual difference in appearance among species. Yet a truly robust vision system must be able to handle a variety of such species, preferably with no operator intervention required when changing from one species to another. Secondly, there is a good deal of variability in the definition of what constitutes a removable defect. The hardwood furniture and fixture industry is diverse in the nature of the products that it makes. The products range from hardwood flooring to fancy hardwood furniture, from simple mill work to kitchen cabinets. Thus depending on the manufacturer, the product, and the quality of the product the nature of what constitutes a removable defect can and does vary. The vision system must be such that it can be tailored to meet each of these unique needs, preferably without any additional program modifications. This paper will describe the vision system that has been developed. It will assess the current system capabilities, and it will discuss the directions for future research. It will be argued that artificial intelligence methods provide a natural mechanism for attacking this computer vision application.

  6. Fine root dynamics and forest production across a calcium gradient in northern hardwood and conifer ecosystems

    USGS Publications Warehouse

    Park, B.B.; Yanai, R.D.; Fahey, T.J.; Bailey, S.W.; Siccama, T.G.; Shanley, J.B.; Cleavitt, N.L.

    2008-01-01

    Losses of soil base cations due to acid rain have been implicated in declines of red spruce and sugar maple in the northeastern USA. We studied fine root and aboveground biomass and production in five northern hardwood and three conifer stands differing in soil Ca status at Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. Neither aboveground biomass and production nor belowground biomass were related to soil Ca or Ca:Al ratios across this gradient. Hardwood stands had 37% higher aboveground biomass (P = 0.03) and 44% higher leaf litter production (P < 0.01) than the conifer stands, on average. Fine root biomass (<2 mm in diameter) in the upper 35 cm of the soil, including the forest floor, was very similar in hardwoods and conifers (5.92 and 5.93 Mg ha-1). The turnover coefficient (TC) of fine roots smaller than 1 mm ranged from 0.62 to 1.86 y-1 and increased significantly with soil exchangeable Ca (P = 0.03). As a result, calculated fine root production was clearly higher in sites with higher soil Ca (P = 0.02). Fine root production (biomass times turnover) ranged from 1.2 to 3.7 Mg ha-1 y-1 for hardwood stands and from 0.9 to 2.3 Mg ha-1 y -1 for conifer stands. The relationship we observed between soil Ca availability and root production suggests that cation depletion might lead to reduced carbon allocation to roots in these ecosystems. ?? 2008 Springer Science+Business Media, LLC.

  7. Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area

    SciTech Connect

    Mayer, J.J.

    1999-12-17

    Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. The depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery of the wild pig damage, these areas were surveyed on foot to assess the magnitude of the depredation on the planted seedling crop. Foraging by the local wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the surveys, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreatment methodology is thought to have been the primary aspect of the restoration program that initially led the wild pigs to discover the planted seedlings. In addition, it is possible that a combination of other factors associated with odor and taste may have resulted in the selective depredation. Future wetland restoration efforts in areas with wild pigs should consider pretreatment methods and species to be planted. If pretreatment methods and species such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species.

  8. Cryo-scanning electron microscopic study on freezing behavior of xylem ray parenchyma cells in hardwood species

    PubMed

    Fujikawa; Kuroda

    2000-12-01

    Differential thermal analysis (DTA) has indicated that xylem ray parenchyma cells (XRPCs) of hardwood species adapt to freezing of apoplastic water either by deep supercooling or by extracellular freezing, depending upon the species. DTA studies indicated that moderately cold hardy hardwood species exhibiting deep supercooling in the XRPCs were limited in latitudinal distribution within the -40 degrees C isotherm, while very hardy hardwood species exhibiting extracellular freezing could distribute in colder areas beyond the -40 degrees C isotherm. Predictions based on the results of DTA, however, indicate that XRPCs exhibiting extracellular freezing may appear not only in very hardy woody species native to cold areas beyond the -40 degrees C isotherm but also in less hardy hardwood species native to tropical and subtropical zones as well as in a small number of moderately hardy hardwood species native to warm temperate zones. Cryo-scanning electron microscopic (cryo-SEM) studies on the freezing behavior of XRPCs have revealed some errors in DTA. These errors are originated mainly due to the overlap between exotherms produced by freezing of water in apoplastic spaces (high temperature exotherms, HTEs) and exotherms produced by freezing of intracellular water of XRPCs by breakdown of deep supercooling (low temperature exotherms, LTEs), as well as to the shortage of LTEs produced by intracellular freezing of XRPCs. In addition, DTA results are significantly affected by cooling rates employed. Further, cryo-SEM observations, which revealed the true freezing behavior of XRPCs, changed the previous knowledge of freezing behavior of XRPCs that had been obtained by freeze-substitution and transmission electron microscopic studies. Cryo-SEM results, in association with results obtained from DTA that were reconfirmed or changed by observation using a cryo-SEM, revealed a clear tendency of the freezing behavior of XRPCs in hardwood species to change with changes in the

  9. Hardwood re-sprout control in hydrologically restored Carolina Bay depression wetlands.

    SciTech Connect

    Moser, Lee, Justin

    2009-06-01

    Carolina bays are isolated depression wetlands located in the upper coastal plain region of the eastern Unites States. Disturbance of this wetland type has been widespread, and many sites contain one or more drainage ditches as a result of agricultural conversion. Restoration of bays is of interest because they are important habitats for rare flora and fauna species. Previous bay restoration projects have identified woody competitors in the seedbank and re-sprouting as impediments to the establishment of herbaceous wetland vegetation communities. Three bays were hydrologically restored on the Savannah River Site, SC, by plugging drainage ditches. Residual pine/hardwood stands within the bays were harvested and the vegetative response of the seedbank to the hydrologic change was monitored. A foliar herbicide approved for use in wetlands (Habitat® (Isopropylamine salt of Imazapyr)) was applied on one-half of each bay to control red maple (Acer rubrum L.), sweet gum (Liquidambar styraciflua L.), and water oak (Quercus nigra L.) sprouting. The effectiveness of the foliar herbicide was tested across a hydrologic gradient in an effort to better understand the relationship between depth and duration of flooding, the intensity of hardwood re-sprout pressure, and the need for hardwood management practices such as herbicide application.

  10. Municipal wastewater effects on nitrogen cycling in a mature hardwood forest

    SciTech Connect

    Kim, D.Y.

    1992-01-01

    Land disposal of municipal wastewater is considered ecologically acceptable and cost effective. The success of land treatment systems, however, requires proper functioning of all ecosystem components. The impact of municipal wastewater irrigation on the structure and function of an Appalachian hardwood forest in Virginia was investigated. Four irrigation rates (17.5, 35, 70, and 140 cm yr[sup [minus]1]) were applied in this hardwood forest, and their effects on forest nutrient cycling were monitored for two years. Tree growth, seedling reproduction, tree mortality, species diversity, and N sequestering by vegetation were not changed significantly. Herbaceous ground cover increased due to irrigation, except for the 140 cm yr[sup [minus]1] treatment where the heavy spray caused physical damage to the cover. Depending on the rate applied, the mature hardwood forest system sequestered only [minus]3.4 to 8.2 kg N ha yr[sup [minus]1] in the aboveground biomass. Therefore, the fate of added N to the system became a function of N transformation processes in the soil. Nitrogen mineralization and nitrification increased as irrigation increased. Denitrification rates were not affected by irrigation; the process of denitrification did not constitute a significant N output from the forest system. The additional soil nitrate (NO[sub 3][sup [minus

  11. Changes in faunal and vegetation communities along a soil calcium gradient in northern hardwood forests

    USGS Publications Warehouse

    Beier, Colin M.; Woods, Anne M.; Hotopp, Kenneth P.; Gibbs, James P.; Mitchell, Myron J.; Dovciak, Martin; Leopold, Donald J.; Lawrence, Gregory B.; Page, Blair D.

    2012-01-01

    Depletion of Ca from forest soils due to acidic deposition has had potentially pervasive effects on forest communities, but these impacts remain largely unknown. Because snails, salamanders, and plants play essential roles in the Ca cycle of northern hardwood forests, we hypothesized that their community diversity, abundance, and structure would vary with differences in biotic Ca availability. To test this hypothesis, we sampled 12 upland hardwood forests representing a soil Ca gradient in the Adirondack Mountains, New York (USA), where chronic deposition has resulted in acidified soils but where areas of well-buffered soils remain Ca rich due to parent materials. Along the gradient of increasing soil [Ca2+], we observed increasing trends in snail community richness and abundance, live biomass of redback salamanders (Plethodon cinereus (Green, 1818)), and canopy tree basal area. Salamander communities were dominated by mountain dusky salamanders (Desmognathus ochrophaeus Cope, 1859) at Ca-poor sites and changed continuously along the Ca gradient to become dominated by redback salamanders at the Ca-rich sites. Several known calciphilic species of snails and plants were found only at the highest-Ca sites. Our results indicated that Ca availability, which is shaped by geology and acidic deposition inputs, influences northern hardwood forest ecosystems at multiple trophic levels, although the underlying mechanisms require further study.

  12. Herpetofaunal Response to Gap and Skidder-Rut Wetland Creation in a Southern Bottomland Hardwood Forest.

    SciTech Connect

    Cromer R.B.; Lanham J.D.; Hanlin H.H.

    2002-05-01

    Herpetofaunal Response to Gap and Skidder-Rut Wetland Creation in a Southern Bottomland Hardwood Forest. Cromer R.B., J.D.Lanham, and H.H. Hanlin.Forest Science, 1 May 2002, vol. 48, iss. 2, pp. 407-413(7) We compared herpetofaunal communities in recently harvested gaps, skidder trails, and unharvested depressional wetlands to assess the effects of group-selection harvesting and skidder traffic on reptiles and amphibians in a southern bottomland hardwood forest. From January 1, 1997 to December 31, 1998 we captured 24,292 individuals representing 55 species of reptiles and amphibians at the Savannah River Site in Barnwell County, South Carolina. Forty-two species (n = 6,702 individuals) were captured in gaps, 43 species (n = 8,863 individuals) were captured along skid trails between gaps and 43 species (n = 8,727 individuals) were captured in bottomland depressions over the 2 yr period. Three vegetation variables and six environmental variables were correlated with herpetofaunal abundance. Salamander abundance, especially for species in the genus Ambystoma, was negatively associated with areas with less canopy cover and pronounced rutting (i.e., gaps and skidder trails). Alternatively, treefrog (Hylidae) abundance was positively associated with gap creation. Results from this study suggest that group selection harvests and skidder rutting may alter the herpetofaunal species composition in southern bottomland hardwoods by increasing habitat suitability for some species while diminishing it for others.

  13. Novel process for the coproduction of xylo-oligosaccharides, fermentable sugars, and lignosulfonates from hardwood.

    PubMed

    Huang, Caoxing; Jeuck, Ben; Du, Jing; Yong, Qiang; Chang, Hou-Min; Jameel, Hasan; Phillips, Richard

    2016-11-01

    Many biorefineries have not been commercialized due to poor economic returns from final products. In this work, a novel process has been developed to coproduce valuable sugars, xylo-oligosaccharides, and lignosulfonates from hardwood. The modified process includes a mild autohydrolysis pretreatment, which enables for the recovery of the xylo-oligosaccharides in auto-hydrolysate. Following enzymatic hydrolysis, the residue is sulfomethylated to produce lignosulfonates. Recycling the sulfomethylation residues increased both the glucan recovery and lignosulfonate production. The glucose recovery was increased from 81.7% to 87.9%. Steady state simulation using 100g of hardwood produced 46.7g sugars, 5.9g xylo-oligosaccharides, and 25.7g lignosulfonates, which were significantly higher than that produced from the no-recycling process with 39.1g sugars, 5.9g xylo-oligosaccharides, and 15.0g lignosulfonates. The results indicate that this novel biorefinery process can improve the production of fermentable sugars and lignosulfonate from hardwood as compared to a conventional biorefinery process. PMID:27543951

  14. Hardwood energy crops and wildlife diversity: Investigating potential benefits for breeding birds and small mammals

    SciTech Connect

    Schiller, A.; Tolbert, V.R.

    1996-08-01

    Hardwood energy crops have the potential to provide a profit to growers as well as environmental benefits (for water quality, soil stabilization, chemical runoff, and wildlife habitat). Environmental considerations are important for both sustainable development of bioenergy technologies on agricultural lands, and for public support. The Environmental Task of the US DOE`s Biofuels feedstock Development Program (BFDP) is working with industry, universities and others to determine how to plant, manage and harvest these crops to maximize environmental advantages and minimize impacts while economically meeting production needs. One research objective is to define and improve wildlife habitat value of these energy crops by exploring how breeding birds and small mammals use them. The authors have found increased diversity of birds in tree plantings compared to row crops. However, fewer bird and small mammal species use the tree plantings than use natural forest. Bird species composition on hardwood crops studied to date is a mixture of openland and forest bird species. Restricted research site availability to date has limited research to small acreage sites of several years of age, or to a few larger acreage but young (1--2 year) plantings. Through industry collaboration, research began this season on bird use of diverse hardwood plantings (different ages, acreages, tree species) in the southeast. Together with results of previous studies, this research will help define practical energy crop guidelines to integrate native wildlife benefits with productive energy crops.

  15. Landfill leachate treatment with willows and poplars--efficiency and plant response.

    PubMed

    Dimitriou, I; Aronsson, P

    2010-11-01

    Irrigation of willow and poplar short-rotation coppice with landfill leachate is an increasingly interesting treatment option. Minimal leaching to groundwater and disturbance to plant growth must be ensured, but in such systems, where various site-specific factors interact, a case-specific approach is needed to determine potential hazards. This paper compares the effect of leachate irrigation on willow grown in clay lysimeters and poplar grown in sand lysimeters. Leachate irrigation increased willow biomass production, but not that of poplar. Near-zero nitrate-N concentrations were found in drainage water for both species after 2 years of irrigation. Ability to retain total N and P, and TOC was relatively high for willow, taking into account the large amounts supplied, and better than for poplar. To reduce environmental risks the irrigation load should be reduced, but if leachate concentrations are reduced, the irrigation load can be as high as 6mm/day. PMID:20650625

  16. The effects of high-tannin leaf litter from transgenic poplars on microbial communities in microcosm soils

    PubMed Central

    Winder, Richard S.; Lamarche, Josyanne; Constabel, C. Peter; Hamelin, Richard C.

    2013-01-01

    The impacts of leaf litter from genetically modified hybrid poplar accumulating high levels of condensed tannins (proanthocyanidins) were examined in soil microcosms consisting of moss growing on sieved soil. Moss preferentially proliferated in microcosms with lower tannin content; DGGE (denaturing gradient gel electrophoresis) detected increased fungal diversity in microcosms with low-tannin litter. The proportion of cloned rDNA sequences from Actinobacteria decreased with litter addition while Bacteroidetes, Chloroflexi, Cyanobacteria, and α-Proteobacteria significantly increased. β-Proteobacteria were proportionally more numerous at high-tannin levels. Tannins had no significant impact on overall diversity of bacterial communities analyzed with various estimators. There was an increased proportion of N-fixing bacteria corresponding to the addition of litter with low-tannin levels. The addition of litter increased the proportion of Ascomycota/Basidiomycota. Dothideomycetes, Pucciniomycetes, and Tremellomycetes also increased and Agaricomycetes decreased. Agaricomycetes and Sordariomycetes were significantly more abundant in controls, whereas Pucciniomycetes increased in soil with litter from transformed trees (P = 0.051). Richness estimators and diversity indices revealed no significant difference in the composition of fungal communities; PCoA (principal coordinate analyses) partitioned the fungal communities into three groups: (i) those with higher amounts of added tannin from both transformed and untransformed treatments, (ii) those corresponding to soils without litter, and (iii) those corresponding to microcosms with litter added from trees transformed only with a β-glucuronidase control vector. While the litter from transformed poplars had significant effects on soil microbe communities, the observed impacts reflected known impacts on soil processes associated with tannins, and were similar to changes that would be expected from natural variation in

  17. Hydroxylated Metabolites of 4-Monochlorobiphenyl and Its Metabolic Pathway in Whole Poplar Plants

    PubMed Central

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

    2010-01-01

    4-Monochlorobiphenyl (CB3), mainly an airborne pollutant, undergoes rapid biotransformation to produce hydroxylated metabolites (OH-CB3s). However, up to now, hydroxylation of CB3 has not been studied in living organisms. In order to explore the formation of hydroxylated metabolites of CB3 in whole plants, poplars (Populus deltoides × nigra, DN34) were exposed to CB3 for 10 days. Poplars are a model plant with complete genomic sequence, and they are widely used in phytoremediation. Results showed poplar plants can metabolize CB3 into OH-CB3s. Three monohydroxy metabolites, including 2′-hydroxy-4-chlorobiphenyl (2′OH-CB3), 3′-hydroxy-4-chlorobiphenyl (3′OH-CB3) and 4′-hydroxy-4-chlorobiphenyl (4′OH-CB3), were identified in hydroponic solution and in different parts of poplar plant. The metabolite 4′OH-CB3 was the major product. In addition, there were two other unknown monohydroxy metabolites of CB3 found in whole poplar plants. Based on their physical and chemical properties, they are likely to be 2-hydroxy-4-chlorobiphenyl (2OH-CB3) and 3-hydroxy-4-chlorobiphenyl (3OH-CB3). Compared to the roots and leaves, the middle portion of the plant (the middle wood and bark) had higher concentrations of 2′OH-CB3, 3′OH-CB3 and 4′OH-CB3, which suggests that these hydroxylated metabolites of CB3 are easily translocated in poplars from roots to shoots. The total masses of 2′OH-CB3, 3′OH-CB3 and 4′OH-CB3 in whole poplar plants were much higher than those in solution, strongly suggesting that it is mainly the poplar plant itself which metabolizes CB3 to OH-CB3s. Finally, the data suggest that the metabolic pathway be via epoxide intermediates. PMID:20402517

  18. Quantification of carbon sources for isoprene emission in poplar leaves

    NASA Astrophysics Data System (ADS)

    Kreutzwieseer, J.; Graus, M.; Schnitzler, J. P.; Heizmann, U.; Rennenberg, H.; Hansel, A.

    2003-12-01

    Isoprene is the most abundant volatile organic compound emitted by plants and in particular by trees. Current interest in understanding its biosynthesis in chloroplasts is forced by the important role isoprene plays in atmospheric chemistry. Leaf isoprene formation is closely linked to photosynthesis by a dynamic use of recently fixed photosynthetic precursors in the chloroplast. Under steady state conditions in [13C]CO2 atmosphere approximately 75 % of isoprene became labeled within minutes. The source of unlabeled C is suggested to be of extra-chloroplastidic and/or from starch degradation. In order to test whether these alternative carbon sources - leaf internal C-pools and xylem-transported carbohydrates, contribute to leaf isoprene formation in poplar (Populus tremula x P. alba) on-line proton-transfer-reaction-mass spectrometry (PTR-MS) was used to follow 13C-labeling kinetics.

  19. Dechlorination of PCBs in the rhizosphere of Switchgrass and Poplar

    PubMed Central

    Meggo, Richard E.; Schnoor, Jerald L.; Hu, Dingfei

    2014-01-01

    Polychlorinated biphenyl (PCB) congeners (PCB 52, 77, and 153) singly and in mixture were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks. There was evidence of reductive dechlorination in both planted and unplanted systems, but the planted microcosms with fully developed roots and rhizospheres showed greater biotransformation than the unplanted reactors. These dechlorination products accounted for approximately all of the molar mass of parent compound lost. Based on the transformation products, reductive dechlorination pathways are proposed for rhizospheric biotransformation of PCB 52, 77, and 153. This is the first report of rhizosphere biotransformation pathways for reductive dechlorination in marginally aerobic, intermittently flooded soil as evidenced by a mass balance on transformation products. PMID:23603468

  20. Identification and Evaluation of Strain B37 of Bacillus subtilis Antagonistic to Sapstain Fungi on Poplar Wood

    PubMed Central

    Zhang, XiaoHua; Zhao, GuiHua; Li, DeWei; Li, ShunPeng; Hong, Qing

    2014-01-01

    Devaluation of poplar products by sapstain accounts for huge and unpredictable losses each year in China. We had isolated four poplar sapstain fungi, Ceratocystis adiposa Hz91, Lasiodiplodia theobromae YM0737, L. theobromae Fx46, and Fusarium sp. YM05, from five poplar varieties and 13 antagonistic bacteria from nine diverse varieties. After being experimented with agar plates, wood chips, and enzyme activities, strain B37 was identified as the best poplar sapstain biocontrol bacterium. The strain B37 was identified as Bacillus subtilis using sequences of the 16S rRNA gene, physiological biochemical, and morphological characteristics. PMID:25401124

  1. Effects of wildlife forestry on abundance of breeding birds in bottomland hardwood forests of Louisiana

    USGS Publications Warehouse

    Norris, Jennifer L.; Chamberlain, Michael J.; Twedt, Daniel J.

    2009-01-01

    Effects of silvicultural activities on birds are of increasing interest because of documented national declines in breeding bird populations for some species and the potential that these declines are in part due to changes in forest habitat. Silviculturally induced disturbances have been advocated as a means to achieve suitable forest conditions for priority wildlife species in bottomland hardwood forests. We evaluated how silvicultural activities on conservation lands in bottomland hardwood forests of Louisiana, USA, influenced species-specific densities of breeding birds. Our data were from independent studies, which used standardized point-count surveys for breeding birds in 124 bottomland hardwood forest stands on 12 management areas. We used Program DISTANCE 5.0, Release 2.0 (Thomas et al. 2006) to estimate density for 43 species with > 50 detections. For 36 of those species we compared density estimates among harvest regimes (individual selection, group selection, extensive harvest, and no harvest). We observed 10 species with similar densities in those harvest regimes compared with densities in stands not harvested. However, we observed 10 species that were negatively impacted by harvest with greater densities in stands not harvested, 9 species with greater densities in individual selection stands, 4 species with greater densities in group selection stands, and 4 species with greater densities in stands receiving an extensive harvest (e.g., > 40% canopy removal). Differences in intensity of harvest influenced densities of breeding birds. Moreover, community-wide avian conservation values of stands subjected to individual and group selection, and stands not harvested, were similar to each other and greater than that of stands subjected to extensive harvest that removed > 40% canopy cover. These results have implications for managers estimating breeding bird populations, in addition to predicting changes in bird communities as a result of prescribed and future

  2. Influences of Herbivory and Canopy Opening Size on Forest Regeneration in a Southern Bottomland Hardwood Forest

    SciTech Connect

    Castleberry, S.B.; Ford, W.M.; Miller, K.V.; Smith, W.P.

    1999-07-06

    Examination of the effects on white-tail deer browsing and canopy opening size on relative abundance and diversity of woody and herbaceous regeneration in various sized forest openings in a Southern bottomland hardwood forest over three growing seasons (1995-1997). Herbaceous richness, diversity or evenness did not differ among exclosure types in any year of the study. Overall browsing rates on both woody and herbaceous vegetation were low throughout all the three years of the study. Low browsing rates reflect seasonal changes in habitat use by deer. Other factors may have influenced the initial vegetative response more than herbivory or gap size.

  3. Foraging behavior of three passerines in mature bottomland hardwood forests during summer.

    SciTech Connect

    Buffington, J., Matthew; Kilgo, John, C.; Sargent, Robert, A.; Miller, Karl, V.; Chapman, Brian, R.

    2001-08-01

    Attention has focused on forest management practices and the interactions between birds and their habitat, as a result of apparent declines in populations of many forest birds. Although avian diversity and abundance have been studied in various forest habitats, avian foraging behavior is less well known. Although there are published descriptions of avian foraging behaviors in the western United States descriptions from the southeastern United States are less common. This article reports on the foraging behavior of the White-eyed Vireo, Northern Parula, and Hooded Warbler in mature bottomland hardwood forests in South Carolina.

  4. Physiological and transcriptional regulation in poplar roots and leaves during acclimation to high temperature and drought.

    PubMed

    Jia, Jingbo; Li, Shaojun; Cao, Xu; Li, Hong; Shi, Wenguang; Polle, Andrea; Liu, Tong-Xian; Peng, Changhui; Luo, Zhi-Bin

    2016-05-01

    To elucidate the physiological and transcriptional regulatory mechanisms that underlie the responses of poplars to high temperature (HT) and/or drought in woody plants, we exposed Populus alba × Populus tremula var. glandulosa saplings to ambient temperature (AT) or HT under 80 or 40% field capacities (FC), or no watering. HT increased the foliar total carbon (C) concentrations, and foliar δ(13) C and δ(18) O. HT triggered heat stress signaling via increasing levels of abscisic acid (ABA) and indole-3-acetic acid (IAA) in poplar roots and leaves. After perception of HT, poplars initiated osmotic adjustment by increasing foliar sucrose and root galactose levels. In agreement with the HT-induced heat stress and the changes in the levels of ABA and carbohydrates, we detected increased transcript levels of HSP18 and HSP21, as well as NCED3 in the roots and leaves, and the sugar transporter gene STP14 in the roots. Compared with AT, drought induced greater enhancement of foliar δ(13) C and δ(18) O in poplars at HT. Similarly, drought caused greater stimulation of the ABA and foliar glucose levels in poplars at HT than at AT. Correspondingly, desiccation led to greater increases in the mRNA levels of HSP18, HSP21, NCED3, STP14 and INT1 in poplar roots at HT than at AT. These results suggest that HT has detrimental effects on physiological processes and it induces the transcriptional regulation of key genes involved in heat stress responses, ABA biosynthesis and sugar transport and HT can cause greater changes in drought-induced physiological and transcriptional responses in poplar roots and leaves. PMID:26497326

  5. Practical salinity management for leachate irrigation to poplar trees.

    PubMed

    Smesrud, Jason K; Duvendack, George D; Obereiner, James M; Jordahl, James L; Madison, Mark F

    2012-01-01

    Landfill leachate can be beneficially reused for irrigation of fiber crops with appropriate attention to nutrient and salinity management. The Riverbend Landfill in Western Oregon has been effectively practicing irrigation of landfill leachate to poplar trees since 1993. Over that time, the site has been adaptively managed to control salinity impacts to the tree crop while beneficially utilizing the applied water and nutrients during each growing season. Representative leachate irrigation water has ranged in concentration of total dissolved solids from 777 to 6,940 mg/L, chloride from 180 to 1,760 mg/L and boron from 3.2 to 7.3 mg/L. Annual leachate irrigation applications have also ranged between 102 and 812 mm/yr. Important conclusions from this site have included: 1) Appropriate tree clone selection and tree stand spacing, thinning, and harvest rotations are critical to maintaining a productive tree stand that is resilient and resistant to salt stress. The most effective combinations have included clones DN-34, OP-367, 184-411, 49-177, and 15-29 planted at spacing of 3.7-m x 1.8-m to 3.7-m x 3.7-m; 2) Leaf tissue boron levels are closely correlated to soil boron levels and can be managed with leaching. When leaf tissue boron levels exceed 200 to 250 mg/kg, signs of salt stress may emerge and should be monitored closely; 3) Salinity from leachate irrigation can be managed to sustain a healthy tree crop by controlling mass loading rates and providing appropriate irrigation blending if necessary. Providing freshwater irrigation following each leachate irrigation and targeting freshwater irrigation as 30 percent of total irrigation water applied has successfully controlled salt impacts to vegetation; and 4) Drip irrigation generally requires more careful attention to long-term soil salinity management than spray irrigation. Moving drip irrigation tubes periodically to prevent the formation of highly saline zones within the soil profile is important. In this paper, a

  6. An Integrated Functional Genomics Consortium to Increase Carbon Sequestration in Poplars: Optimizing Aboveground Carbon Gain

    SciTech Connect

    Karnosky, David F; Podila, G Krishna; Burton, Andrew J

    2009-02-17

    This project used gene expression patterns from two forest Free-Air CO2 Enrichment (FACE) experiments (Aspen FACE in northern Wisconsin and POPFACE in Italy) to examine ways to increase the aboveground carbon sequestration potential of poplars (Populus). The aim was to use patterns of global gene expression to identify candidate genes for increased carbon sequestration. Gene expression studies were linked to physiological measurements in order to elucidate bottlenecks in carbon acquisition in trees grown in elevated CO2 conditions. Delayed senescence allowing additional carbon uptake late in the growing season, was also examined, and expression of target genes was tested in elite P. deltoides x P. trichocarpa hybrids. In Populus euramericana, gene expression was sensitive to elevated CO2, but the response depended on the developmental age of the leaves. Most differentially expressed genes were upregulated in elevated CO2 in young leaves, while most were downregulated in elevated CO2 in semi-mature leaves. In P. deltoides x P. trichocarpa hybrids, leaf development and leaf quality traits, including leaf area, leaf shape, epidermal cell area, stomatal number, specific leaf area, and canopy senescence were sensitive to elevated CO2. Significant increases under elevated CO2 occurred for both above- and belowground growth in the F-2 generation. Three areas of the genome played a role in determining aboveground growth response to elevated CO2, with three additional areas of the genome important in determining belowground growth responses to elevated CO2. In Populus tremuloides, CO2-responsive genes in leaves were found to differ between two aspen clones that showed different growth responses, despite similarity in many physiological parameters (photosynthesis, stomatal conductance, and leaf area index). The CO2-responsive clone shunted C into pathways associated with active defense/response to stress, carbohydrate/starch biosynthesis and subsequent growth. The CO2

  7. Enantioselective Transport and Biotransformation of Chiral Hydroxylated Metabolites of Polychlorinated Biphenyls in Whole Poplar Plants

    PubMed Central

    2015-01-01

    Hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs) have been found to be ubiquitous in the environment due to the oxidative metabolism of their parent PCBs. With more polarity, OH-PCBs may be more toxic and mobile than their parent compounds. However, the behavior and fate of OH-PCBs have been neglected in the environment because they are not the original contaminants. Some of these hydroxylated metabolites are chiral, and chiral compounds can be used to probe biological metabolic processes. Therefore, chiral OH-PCBs were selected to study their uptake, translocation, transformation, and enantioselectivity in plants in this work. Poplars (Populus deltoides × nigra, DN34), a model plant with complete genomic sequence, were hydroponically exposed to 5-hydroxy-2,2′,3,4′,6-pentachlorobiphenyl (5-OH-PCB91) and 5-hydroxy-2,2′,3,5′,6-pentachlorobiphenyl (5-OH-PCB95) for 10 days. Chiral 5-OH-PCB91 and 5-OH-PCB95 were clearly shown to be sorbed, taken up, and translocated in whole poplars, and they were detected in various tissues of whole poplars. However, the enantioselectivity of poplar for 5-OH-PCB91 and 5-OH-PCB95 proved to be quite different. The second-eluting enantiomer of OH-PCB95, separated on a chiral column (Phenomenex Lux Cellulose-1), was enantioselectively removed in whole poplar. Enantiomeric fractions in the middle xylem, top bark, top xylem, and stem, reached 0.803 ± 0.022, 0.643 ± 0.110, 0.835 ± 0.087, and 0.830 ± 0.029, respectively. Therefore, 5-OH-PCB95 was significantly enantioselectively biotransformed inside poplar tissues, in contrast to nearly racemic mixtures of 5-OH-PCB95 remaining in hydroponic solutions. Unlike 5-OH-PCB95, 5-OH-PCB91 remained nearly racemic in most tissues of whole poplars during 10 day exposure, suggesting the enantiomers of 5-OH-PCB91 were equally transported and metabolized in whole poplars. This is the first evidence of enantioselectivity of chiral OH-PCBs and suggests that poplars can

  8. Final Report: Exudation by Poplar Ectomycorrhizas: Qualitative and Quantitative Assessment of C Sequestration

    SciTech Connect

    Cumming, J R

    2012-11-12

    Study 1. We compared mycorrhizal Populus tremuloides inoculated with Laccaria bicolor and nonmycorrhizal (NM) P. tremuloides seedlings grown under different levels of P nutrition. Decreasing concentrations of P significantly increased the activity of reactive oxygen scavenging enzymes. In addition, phosphoenolpyruvate carboxylase activity increased under P limitation. P deficiency also increased organic acid exudation and total organic carbon exudation. Colonization by L. bicolor reduced the P concentration thresholds where these physiological changes occurred. Study 2. We assessed the influences of ectomycorrhizal colonization on phosphate limitation responses of trembling aspen. Photosynthetic CO2 uptake was reduced in NM poplar, but not in plants colonized by L. bicolor or P. involutus. Reductions in shoot and root biomass in NM plants were substantially greater than reductions in plants colonized by either ectomycorrhizal fungi. Leaf starch and sugar concentrations declined with Pi limitation across mycorrhizal treatments, but were higher in plants colonized by L. bicolor and P. involutus. In roots, starch concentrations were greater in NM plants with Pi limitation. In roots, sugars were significantly higher in NM plants compared to mycorrhizal plants and increased significantly in NM plants under Pi limitation. Concentrations were unaffected by Pi limitation in plants colonized by L. bicolor or P. involutus. Study 3. We analyzed proteins that were differentially expressed during the mycorrhizal association. A comparison of global protein expression elucidated broad differences in protein profiles between NM plants and plants colonized by ectomycorrhizal (ECM) or arbuscular mycorrhizal (AM) fungi as well as differences between the ECM fungi L. bicolor and P. involutus. Plants colonized by P. involutus and G. intraradices exhibited unique patterns of up/down-regulated proteins compared to NM plants, whereas plants colonized by L. bicolor exhibited patterns of

  9. Reforestation of bottomland hardwoods and the issue of woody species diversity

    USGS Publications Warehouse

    Allen, J.A.

    1997-01-01

    Bottomland hardwood forests in the southcentral United States have been cleared extensively for agriculture, and many of the remaining forests are fragmented and degraded. During the last decade, however, approximately 75,000 ha of land-mainly agricultural fields-have been replanted or contracted for replanting, with many more acres likely to be reforested in the near future. The approach used in most reforestation projects to date has been to plant one to three overstory tree species, usually Quercus spp. (oaks), and to rely on natural dispersal for the establishment of other woody species. I critique this practice by two means. First, a brief literature review demonstrates that moderately high woody species diversity occurs in natural bottomland hardwood forests in the region. This review, which relates diversity to site characteristics, serves as a basis for comparison with stands established by means of current reforestation practices. Second, I reevaluate data on the invasion of woody species from an earlier study of 10 reforestation projects in Mississippi,with the goal of assessing the likelihood that stands with high woody species diversity will develop. I show that natural invasion cannot always be counted on to produce a diverse stand, particularly on sites more than about 60 m from an existing forest edge. I then make several recommendations for altering current reforestation pactices in order to establish stands with greater woody species diversity, a more natural appearance,and a more positive environmental impact at scales larger than individual sites.

  10. Effects of canopy gaps and flooding on homopterans in a bottomland hardwood forest

    USGS Publications Warehouse

    Gorham, L.E.; King, S.L.; Keeland, B.D.; Mopper, S.

    2002-01-01

    Canopy disturbance is a major factor affecting forest structure and composition and, as a result of habitat alterations, can influence insect communities. We initiated a field study to quantify the effects of canopy disturbance on aerial insect abundance and distribution within a bottomland hardwood forest along the Cache River, Arkansas, USA. We used passive flight-intercept traps to sample insects in canopy gap and forest interior habitats from May to July in 1996, 1997, and 1998. The hydrologic conditions of our study site varied among years: 1996 was relatively dry, 1997 incurred a long-duration flood, and 1998 was moderately wet. Of the 34,000+ Homopterans collected, many groups were distributed in a non-uniform manner among years and between habitats. Total Homopterans, two families of Homopterans, and six morphospecies were more abundant in canopy gaps than interior forest. Many Homopteran taxa were least abundant in 1997 following almost six months of flooding. Alternatively, relatively large Homopteran abundances were associated with the dry conditions of 1996 and the moderately wet conditions of 1998. Differences in Homopteran abundance among years and habitats may be related to differences in vegetation density. Canopy gaps supported more vegetation cover than the interior forest in all but the first sampling interval. In addition, similar to Homopteran abundance, vegetation density was lower in 1997 than in 1998. These results demonstrate that natural disturbance and flooding contribute to Homopteran abundance and distribution patterns in bottomland hardwood forests of the south central United States. ?? 2002, The Society of Wetland Scientists.

  11. Biology and management of insect pests in North American intensively managed hardwood forest systems.

    SciTech Connect

    Coyle, David R.; Nebeker, T., E.; Hart, E., R.; Mattson, W., J.

    2005-01-01

    Annu. Rev. Entomol. 50:1-29. Abstract Increasing demand for wood and wood products is putting stress on traditional forest production areas, leading to long-term economic and environmental concerns. Intensively managed hardwood forest systems (IMHFS), grown using conventional agricultural as well as forestry methods, can help alleviate potential problems in natural forest production areas. Although IMHFS can produce more biomass per hectare per year than natural forests, the ecologically simplified, monocultural systems may greatly increase the crops susceptibility to pests. Species in the genera Populus and Salix comprise the greatest acreage in IMHFS in North America, but other species, including Liquidambar styracifua and Platanus occidentalis, are also important. We discuss life histories, realized and potential damage, and management options for the most economically infuential pests that affect these hardwood species. The substantial inherent challenges associated with pest management in the monocultural environments created by IMHFS are reviewed. Finally, we discuss ways to design IMHFS that may reduce their susceptibility to pests, increase their growth and productivity potential, and create a more sustainable environment.

  12. Higher heating values for pellets made from short rotation biomass of hardwood species

    SciTech Connect

    Chow, P.; Rolfe, G.L.; Lambert, R.O. Jr.

    1995-11-01

    The use of pellitized woody biomass for fuel has increased substantially in recent years. The purpose of this study was to determine the higher heating values and ash content on four-year-old short-rotation trees: autumn olive, black alder, cottonwood and sycamore. These plantations were established on marginal agricultural land that was not suitable for food production in Midwestern United States. The effects of tree species, site, and regeneration technique on the fuel value were determined. For comparison purposes, the heat content of three commercial lumber species was also obtained. Test results indicated that the planting sites (bottomland versus upperland) and regeneration method (seeding-grown versus coppice-grown) factors did not affect the higher heating values of all pellitized specimens. The heat values averaged 4728 calories per oven-dry gram, which is greater than the 4580 cal/gram of three commercial hardwoods. The main factor species, as well as the interactions of species by site, species by regeneration, and site by regeneration, were significant factors in determining heat value. Black alder had the highest heat value, followed by autumn olive, cottonwood, and sycamore. Furthermore, a preliminary experiment indicates that alcohol, a liquid fuel, can also be made from the short rotation hardwoods in the laboratory scale. It is likely a pellitized coal product using lignin waste derived from the wood hydrolysis stage of the ethyl alcohol conversion process can also be made in the future.

  13. Surface characteristics of coated soft- and hardwoods due to UV-B ageing

    NASA Astrophysics Data System (ADS)

    Ncube, E.; Meincken, M.

    2010-10-01

    Wood is a valuable building material, but it is susceptible to degradation if left unprotected especially when using less durable species. Protection is commonly achieved by applying a suitable finish that should exhibit sufficient penetration, good adhesion and resistance to photo-degradation and weathering. The performance of wood coatings is largely influenced by the adhesion between the coating and substrate and any degradation of the substrate will also affect the coating. The aim of this study was to determine the degree to which the substrate degrades despite the coating and adds to the ageing of the coating from the interface. This effect can be expected to differ for soft- and hardwoods. Coated wood samples from pine and meranti wood - a soft- and hardwood - were irradiated with UV-B light to detect surface changes at various length scales and to assess the impact of the underlying wood substrate on the ageing performance of a commercially available acrylic coating. Surface modifications were determined with atomic force microscopy, Fourier transform infrared spectroscopy, colour spectroscopy, static contact angle and a surface roughness profiler.

  14. Extracts from hardwood trees used in commercial paper mills contain biologically active neurochemical disruptors.

    PubMed

    Basu, Niladri; Waye, Andrew; Trudeau, Vance L; Arnason, John T

    2012-01-01

    Following on our discovery that pulp and paper mill effluents can interact with, and disrupt, various neurotransmitter receptors and enzymes important to fish reproduction, we tested wood and bark extracts of 14 Eastern North American hardwood trees used in pulp and paper production. Radioligand binding to neurotransmitter receptors, including the dopamine-2 receptor (D2), the gamma aminobutyric acid receptor A (GABA(A)), N-methyl-D-aspartic acid (NMDA) receptor, and muscarinic cholinergic receptor (mACh-R), were significantly changed following in vitro incubations with many but not all extracts. Activities of neurotransmitter-related enzymes monoamine oxidase (MAO), GABA-transaminase (GABA-T), acetylcholinesterase (AChE) and glutamic acid decarboxylase (GAD) were also significantly altered. Butternut wood extracts and the isolated compound juglone significantly inhibited the enzymatic activities of MAO and GAD which we suggest may be part of a mechanism that may negatively affect fish reproduction. Besides giving credence to the hypothesis that neuroactive compounds in pulp and paper effluent may originate in the trees used by mills, the results reported here also indicate important neuropharmacological activities in hardwoods which may help identify new sources of biologically active natural products. PMID:22137476

  15. Relative abundance and species richness of cerambycid beetles in partial cut and uncut bottomland hardwood forests

    USGS Publications Warehouse

    Newell, P.; King, S.

    2009-01-01

    Partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife. However, partial cutting may or may not benefit species dependent on deadwood; harvesting can supplement coarse woody debris in the form of logging slash, but standing dead trees may be targeted for removal. We sampled cerambycid beetles during the spring and summer of 2006 and 2007 with canopy malaise traps in 1- and 2-year-old partial cut and uncut bottomland hardwood forests of Louisiana. We captured a total of 4195 cerambycid beetles representing 65 species. Relative abundance was higher in recent partial cuts than in uncut controls and with more dead trees in a plot. Total species richness and species composition were not different between treatments. The results suggest partial cuts with logging slash left on site increase the abundance of cerambycid beetles in the first few years after partial cutting and that both partial cuts and uncut forest should be included in the bottomland hardwood forest landscape.

  16. Classification of hardwood and swamp forests on the Savannah River Plant, South Carolina

    SciTech Connect

    Whipple, S.A.; Wellman, L.H.; Good, B.J.

    1981-04-01

    Fifty-eignt hardwood and swamp forest stands were sampled on the Savannah River Plant (SRP), South Carolina, to describe the relationship between the vegetational composition and the soil, topographic, and flooding characteristics of each stand. The stands were samples over the range from dry upland to deeply flooded (2.4m) sites. Seven forest communities were recognized. The boundaries between these communities are not usually distinct, but the classification serves as a basis for a discussion of the patterns of hardwood and swamp forests on the SRP and a comparison of this forest variation to variation of other forests in the Southeast. The forest communities found on the most deeply flooded sites are dominated almost exclusively by Taxodium distichum and Nyssa aquatica. With shallower flooding or only winter flooding, Fraxinus pennsylvanica, Acer rubrum, Liquidambar styraciflua, and Quercus laurifolia become important dominants. Mesic sites that are seldom, if ever, flooded are dominated by N. sylvatica, L. styraciflua, and A. rubrum. The driest upland or upper slope positions are dominated by Q. alba, Carya tomentosa, and L. styraciflua.

  17. The vernal dam: Plant-microbe competition for nitrogen in northern hardwood forests. [Allium tricoccum

    SciTech Connect

    Zak, D.R. ); Groffman, P.M. ); Pregitzer, K.S.; Tiedje, J.M. ); Christensen, S. )

    1990-04-01

    Nitrogen (N) uptake by spring ephemeral communities has been proposed as a mechanism that retains N within northern hardwood forests during the season of maximum loss. To understand better the importance of these plants in retaining N, the authors followed the movement of {sup 15}NH{sub 4}{sup +} and {sup 15}NO{sub 3}{sup {minus}} into plant and microbial biomass. Two days following isotope addition, microbial biomass represented the largest labile pool of N and contained 8.5 times as much N as Allium tricoccum L. biomass. Microbial immobilization of {sup 15}N was 10-20 times greater than uptake by A. tricoccum. Nitrification of {sup 15}NH{sub 4}{sup +} was five times lower in cores containing A. tricoccum compared to those without the spring ephemeral. Spring N retention within northern hardwood forests cannot be fully explained by plant uptake because microbial immobilization represented a significantly larger sink for N. Results suggest that plant and microbial uptake of NH{sub 4}{sup +} may reduce the quantity of substrate available for nitrification and thereby lessen the potential for NO{sub 3}{sup {minus}} loss via denitrification and leaching.

  18. Adaptive response of poplar (Populus nigra L.) after prolonged Cd exposure period.

    PubMed

    Jakovljević, Tamara; Bubalo, Marina Cvjetko; Orlović, Sanja; Sedak, Marija; Bilandžić, Nina; Brozinčević, Iva; Redovniković, Ivana Radojčić

    2014-03-01

    An outdoor pot experiment was designed to study the changes of growth parameters, accumulation, and distribution of Cd in poplar (Populus nigra L.) during a prolonged exposure period (growing period of 17 months including three harvest points), allowing the consideration of time effects and prolonged adaptation to Cd stress. Simultaneously, changes to the antioxidant system in roots and leaves were monitored. It was demonstrated that poplar could adapt to the Cd-contaminated soils after prolonged exposure. Total Cd accumulation in the aerial parts of poplar, due to high biomass production and acceptable Cd accumulation parameters, implies that the tested poplar species could be a good candidate for Cd phytoextraction application as well as could be used as phytostabilizer of Cd in heavily polluted soil. Furthermore, the activity of the antioxidant machinery displays both a tissue- and exposure-specific response pattern to different Cd treatments, indicating that strict regulation of the antioxidant defense system is required for the adaptive response of poplar. In addition, this report highlights the importance of prolonged exposure studies of physiological responses of plants, especially for long-life-cycle woody species under heavy metal stress, since some misleading conclusions could be reached after shorter time periods. PMID:24288057

  19. Identification and analysis of phosphorylation status of proteins in dormant terminal buds of poplar

    PubMed Central

    2011-01-01

    Background Although there has been considerable progress made towards understanding the molecular mechanisms of bud dormancy, the roles of protein phosphorylation in the process of dormancy regulation in woody plants remain unclear. Results We used mass spectrometry combined with TiO2 phosphopeptide-enrichment strategies to investigate the phosphoproteome of dormant terminal buds (DTBs) in poplar (Populus simonii × P. nigra). There were 161 unique phosphorylated sites in 161 phosphopeptides from 151 proteins; 141 proteins have orthologs in Arabidopsis, and 10 proteins are unique to poplar. Only 34 sites in proteins in poplar did not match well with the equivalent phosphorylation sites of their orthologs in Arabidopsis, indicating that regulatory mechanisms are well conserved between poplar and Arabidopsis. Further functional classifications showed that most of these phosphoproteins were involved in binding and catalytic activity. Extraction of the phosphorylation motif using Motif-X indicated that proline-directed kinases are a major kinase group involved in protein phosphorylation in dormant poplar tissues. Conclusions This study provides evidence about the significance of protein phosphorylation during dormancy, and will be useful for similar studies on other woody plants. PMID:22074553

  20. Field note: hydraulic containment of a BTEX plume using poplar trees.

    PubMed

    Barac, Tanja; Weyens, Nele; Oeyen, Licy; Taghavi, Safiyh; van der Lelie, Daniel; Dubin, Dirk; Spliet, Marco; Vangronsveld, Jaco

    2009-07-01

    In 1999, 275 poplar trees were planted on a field site near a car factory in order to install a bioscreen. The aim was to combine the biodegradation activities of poplar and its associated rhizosphere and endophytic microorganisms for containing a BTEX contaminated groundwater plume. This BTEX plume occurred as the result of leaking solvents and fuel storage tanks. Monitoring, conducted overa 6-year period (1999-2005) after the planting of the trees suggested that the poplar trees and their associated microorganisms had, once the tree roots reached the contaminated groundwater zone, an active role in the remediation of the BTEX plume, resulting in full containment of the contamination. Analysis of the microbial communities associated with poplar demonstrated that, once the poplar roots got in contact with the BTEX contaminated groundwater, enrichment occurred of both rhizosphere and endophytic bacteria that were able to degrade toluene. Interestingly, once the BTEX plume was remediated, the numbers of toluene degrading rhizosphere and endophytic bacteria decreased below the detection limit, indicating that their population resulted from selective enrichment by the presence of the contaminants. PMID:19810345

  1. Poplar-Root Knot Nematode Interaction: A Model for Perennial Woody Species.

    PubMed

    Baldacci-Cresp, Fabien; Sacré, Pierre-Yves; Twyffels, Laure; Mol, Adeline; Vermeersch, Marjorie; Ziemons, Eric; Hubert, Philippe; Pérez-Morga, David; El Jaziri, Mondher; de Almeida Engler, Janice; Baucher, Marie

    2016-07-01

    Plant root-knot nematode (RKN) interaction studies are performed on several host plant models. Though RKN interact with trees, no perennial woody model has been explored so far. Here, we show that poplar (Populus tremula × P. alba) grown in vitro is susceptible to Meloidogyne incognita, allowing this nematode to penetrate, to induce feeding sites, and to successfully complete its life cycle. Quantitative reverse transcription-polymerase chain reaction analysis was performed to study changes in poplar gene expression in galls compared with noninfected roots. Three genes (expansin A, histone 3.1, and asparagine synthase), selected as gall development marker genes, followed, during poplar-nematode interaction, a similar expression pattern to what was described for other plant hosts. Downregulation of four genes implicated in the monolignol biosynthesis pathway was evidenced in galls, suggesting a shift in the phenolic profile within galls developed on poplar roots. Raman microspectroscopy demonstrated that cell walls of giant cells were not lignified but mainly composed of pectin and cellulose. The data presented here suggest that RKN exercise conserved strategies to reproduce and to invade perennial plant species and that poplar is a suitable model host to study specific traits of tree-nematode interactions. PMID:27135257

  2. Pseudomonas aeruginosa PAO1 virulence factors and poplar tree response in the rhizosphere

    PubMed Central

    Attila, Can; Ueda, Akihiro; Cirillo, Suat L. G.; Cirillo, Jeffrey D.; Chen, Wilfred; Wood, Thomas K.

    2008-01-01

    Summary Whole‐transcriptome analysis was used here for the first time in the rhizosphere to discern the genes involved in the pathogenic response of Pseudomonas aeruginosa PAO1 as well as to discern the response of the poplar tree. Differential gene expression shows that 185 genes of the bacterium and 753 genes of the poplar tree were induced in the rhizosphere. Using the P. aeruginosatranscriptome analysis, isogenic knockout mutants, and two novel plant assays (poplar and barley), seven novel PAO1 virulence genes were identified (PA1385, PA2146, PA2462, PA2463, PA2663, PA4150 and PA4295). The uncharacterized putative haemolysin repressor, PA2463, upon inactivation, resulted in greater poplar virulence and elevated haemolysis while this mutant remained competitive in the rhizosphere. In addition, disruption of the haemolysin gene itself (PA2462) reduced the haemolytic activity of P. aeruginosa, caused less cytotoxicity and reduced barley virulence, as expected. Inactivating PA1385, a putative glycosyl transferase, reduced both poplar and barley virulence. Furthermore, disrupting PA2663, a putative membrane protein, reduced biofilm formation by 20‐fold. Inactivation of PA3476 (rhlI) increased virulence with barley as well as haemolytic activity and cytotoxicity, so quorum sensing is important in plant pathogenesis. Hence, this strategy is capable of elucidating virulence genes for an important pathogen. PMID:21261818

  3. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    PubMed Central

    Foster, Adam J.; Pelletier, Gervais; Tanguay, Philippe; Séguin, Armand

    2015-01-01

    Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen. PMID:26378446

  4. Forest conversion to poplar plantation in a Lombardy floodplain (Italy): effects on soil organic carbon stock

    NASA Astrophysics Data System (ADS)

    Ferré, C.; Comolli, R.; Leip, A.; Seufert, G.

    2014-06-01

    Effects of forest conversion to poplar plantation on soil organic carbon (SOC) stocks were investigated by sampling paired plots in an alluvial area of the Ticino river in Northern Italy. According to land registers and historical aerial photographs, the two sites were part of a larger area of a 200 years-old natural forest that was partly converted to poplar plantation in 1973. The soil sampling of three layers down to a depth of 100 cm was performed at 90 and 70 points in the natural forest (NF) and in the nearby poplar plantation (PP), respectively. The substitution of the natural forest with the poplar plantation strongly modified soil C stock down to a depth of 55 cm, although the management practices at PP were not intensive. By evaluation of equivalent soil masses, the comparison of C stocks (organic layer included) between the different land uses showed a decrease in SOC of 5.7 kg m-2 after 37 years of poplar cultivation, corresponding to more than 1/3 of the initial organic carbon content. The land use change from NF to PP not only affected the stock but also the vertical distribution of SOC: ploughing led to the transfer of SOC from soil surface into the deeper layers resulting in a more uniform allocation of organic carbon in the ploughed layer and disappearance of the SOC stratification observed in the forest.

  5. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    PubMed

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-01-01

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects. PMID:26345739

  6. Assessment of the role of bottomland hardwoods in sediment and erosion control

    USGS Publications Warehouse

    Molinas, A.; Auble, Gregor T.; Segelquist, C.A.; Ischinger, Lee S.

    1988-01-01

    Drainage and clearing of bottomland hardwoods have long been recognized by the U.S. Environmental Protection Agency (EPA) and the U.S. Fish and Wildlife Service (Service) as important impacts of Federal water projects in the lower Mississippi River Valley. More recently, the water quality impacts of such projects (e.g., increases in sediments, nutrients, and pesticides) have also become of concern. In 1984, in an effort to better define problems concerning wetland losses and water degradation, EPA initiated a cooperative project with the Western Energy and Land Use Team (now the National Ecology Research Center) of the Service. Three phases of the project were identified: 1. To collect existing literature and data; 2. To select, develop, and test the utility of methods to quantify the relationships between land use, cover types, soils, hydrology, and water quality (as represented by sediment); and 3. To apply selected methodologies to several sites within the Yazoo Basin of Mississippi to determine the, potential effectiveness of various management alternatives to reduce sediment yield, increase sediment deposition, and improve water quality. Methods development focused on linking a simulation of water and sediment movement to a computerized geographic information system. We had several objectives for the resulting model. We desired that it should: 1. Estimate the importance of bottomland and hardwoods as a cover type that performs the functions of erosion and sediment control, 2. Simulate effects of proportions of ' various cover types and their specific spatial configurations, 3. Be applicable to moderately large spatial areas with minimal site-specific calibration, 4. Simulate spatial patterns of sediment loss-gain over time, and 5. Represent both sediment detachment and transport. While it was recognized that impacts and management alternatives could be sorted roughly into landscape measures and channel measures, the decision was made to focus study efforts

  7. Enhanced vadose zone nitrogen removal by poplar during dormancy.

    PubMed

    Ausland, Hayden; Ward, Adam; Licht, Louis; Just, Craig

    2015-01-01

    A pilot-scale, engineered poplar tree vadose zone system was utilized to determine effluent nitrate (NO3(-)) and ammonium concentrations resulting from intermittent dosing of a synthetic wastewater onto sandy soils at 4.5°C. The synthetic wastewater replicated that of an industrial food processor that irrigates onto sandy soils even during dormancy which can leave groundwater vulnerable to NO3(-) contamination. Data from a 21-day experiment was used to assess various Hydrus model parameterizations that simulated the impact of dormant roots. Bromide tracer data indicated that roots impacted the hydraulic properties of the packed sand by increasing effective dispersion, water content and residence time. The simulated effluent NO3(-) concentration on day 21 was 1.2 mg-N L(-1) in the rooted treatments compared to a measured value of 1.0 ± 0.72 mg-N L(-1). For the non-rooted treatment, the simulated NO3(-) concentration was 4.7 mg-N L(-1) compared to 5.1 ± 3.5 mg-N L(-1) measured on day 21. The model predicted a substantial "root benefit" toward protecting groundwater through increased denitrification in rooted treatments during a 21-day simulation with 8% of dosed nitrogen converted to N2 compared to 3.3% converted in the non-rooted test cells. Simulations at the 90-day timescale provided similar results, indicating increased denitrification in rooted treatments. PMID:26030360

  8. Dual targeted poplar ferredoxin NADP(+) oxidoreductase interacts with hemoglobin 1.

    PubMed

    Jokipii-Lukkari, Soile; Kastaniotis, Alexander J; Parkash, Vimal; Sundström, Robin; Leiva-Eriksson, Nélida; Nymalm, Yvonne; Blokhina, Olga; Kukkola, Eija; Fagerstedt, Kurt V; Salminen, Tiina A; Läärä, Esa; Bülow, Leif; Ohlmeier, Steffen; Hiltunen, J Kalervo; Kallio, Pauli T; Häggman, Hely

    2016-06-01

    Previous reports have connected non-symbiotic and truncated hemoglobins (Hbs) to metabolism of nitric oxide (NO), an important signalling molecule involved in wood formation. We have studied the capability of poplar (Populus tremula×tremuloides) Hbs PttHb1 and PttTrHb proteins alone or with a flavin-protein reductase to relieve NO cytotoxicity in living cells. Complementation tests in a Hb-deficient, NO-sensitive yeast (Saccharomyces cerevisiae) Δyhb1 mutant showed that neither PttHb1 nor PttTrHb alone protected cells against NO. To study the ability of Hbs to interact with a reductase, ferredoxin NADP(+) oxidoreductase PtthFNR was characterized by sequencing and proteomics. To date, by far the greatest number of the known dual-targeted plant proteins are directed to chloroplasts and mitochondria. We discovered a novel variant of hFNR that lacks the plastid presequence and resides in cytosol. The coexpression of PttHb1 and PtthFNR partially restored NO resistance of the yeast Δyhb1 mutant, whereas PttTrHb coexpressed with PtthFNR failed to rescue growth. YFP fusion proteins confirmed the interaction between PttHb1 and PtthFNR in plant cells. The structural modelling results indicate that PttHb1 and PtthFNR are able to interact as NO dioxygenase. This is the first report on dual targeting of central plant enzyme FNR to plastids and cytosol. PMID:27095407

  9. Genomics Mechanisms of Carbon Allocation and Partitioning in Poplar

    SciTech Connect

    Kirst, Matias; Peter, Gary; Martin, Timothy

    2009-07-30

    The genetic control of carbon allocation and partitioning in woody perennial plants is poorly understood despite its importance for carbon sequestration. It is also unclear how environmental cues such as nitrogen availability impact the genes that regulate growth, and biomass allocation and wood composition in trees. To address these questions we phenotyped 396 clonally replicated genotypes of an interspecific pseudo-backcross pedigree of Populus for wood composition and biomass traits in above and below ground organs. The loci that regulate growth, carbon allocation and partitioning under two nitrogen conditions were identified, defining the contribution of environmental cues to their genetic control. Fifty-seven quantitative trait loci (QTL) were identified for twenty traits analyzed. The majority of QTL are specific to one of the two nitrogen treatments, demonstrating significant nitrogen-dependent genetic control. A highly significant genetic correlation was observed between plant growth and lignin/cellulose composition, and QTL co-localization identified the genomic position of potential pleiotropic regulators. Gene expression analysis of all poplar genes was also characterized in differentiating xylem, whole-roots and developing leaves of 192 of the segregating population. By integrating the QTL and gene expression information we identified genes that regulate carbon partitioning and several biomass growth related properties. The work developed in this project resulted in the publication of three book chapters, four scientific articles (three others currently in preparation), 17 presentations in international conferences and two provisional patent applications.

  10. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    SciTech Connect

    ADAMS, S.M.; BEATY, T.W.; BRANDT, C.C.; CHRISTENSEN, S.W.; CICERONE, D.S.

    1998-09-09

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  11. BIOLOGICAL MONITORING PROGRAM FOR EAST FORK POPLAR CREEK

    SciTech Connect

    ADAMS, S.M.; ASHWOOD, T.L.; BEATY, T.W.; BRANDT, C.C.

    1997-10-24

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y- 12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  12. Biological monitoring program for East Fork Poplar Creek

    SciTech Connect

    Adams, S.M.; Ashwood, T.L.; Beaty, T.W.; Brandt, C.C.; Christensen, S.W.; Cicerone, D.S.; Greeley, M.S. Jr.; Hill, W.R.; Kszos, L.S.

    1997-04-18

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC. These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumulation studies, and (4) ecological surveys of the periphyton, benthic macroinvertebrate, and fish communities.

  13. Effect of autohydrolysis on the wettability, absorbility and further alkali impregnation of poplar wood chips.

    PubMed

    Xu, Ningpan; Liu, Wei; Hou, Qingxi; Wang, Peiyun; Yao, Zhirong

    2016-09-01

    Autohydrolysis with different severity factors was performed on poplar wood chips prior to pulping, and the wettability, absorbility and the following impregnation of NaOH solution for the poplar wood chips were then investigated. The results showed that after autohydrolysis pretreatment the porosity, shrinkage and fiber saturation point (FSP) of the poplar wood chips were increased, while the surface contact angle decreased as the severity factor was increased. The autohydrolyzed chips absorbed more NaOH in impregnation that resulted in a low NaOH concentration in the bulk impregnation liquor (i.e., the impregnation liquor outside wood chips), while the concentration in the entrapped liquor (i.e., the impregnation liquor inside wood chips) was increased. Autohydrolysis substantially improved the effectiveness of alkali impregnation. PMID:27259186

  14. Daytime and nighttime wind differentially affects hydraulic properties and thigmomorphogenic response of poplar saplings.

    PubMed

    Huang, Ping; Wan, Xianchong; Lieffers, Victor J

    2016-05-01

    This study tested how wind in daytime and nighttime affects hydraulic properties and thigmomorphogenic response of poplar saplings. It shows that wind in daytime interrupted water balance of poplar plants by aggravating cavitation in the stem xylem under high xylem tension in the daytime, reducing water potential in midday and hence reducing gas exchange, including stomatal conductance and CO2 assimilation. The wind blowing in daytime significantly reduced plant growth, including height, diameter, leaf size, leaf area, root and whole biomass, whereas wind blowing in nighttime only caused a reduction in radial and height growth at the early stage compared with the control but decreased height:diameter ratios. In summary, the interaction between wind loading and xylem tension exerted a negative impact on water balance, gas exchanges and growth of poplar plants, and wind in nighttime caused only a small thigmomorphogenic response. PMID:26541407

  15. 75 FR 7044 - T&S Hardwoods, Inc., Sylva, NC; Notice of Negative Determination Regarding Application for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration T&S Hardwoods, Inc., Sylva, NC; Notice of Negative Determination Regarding Application for Reconsideration By application dated January 5, 2010, a petitioner requested administrative reconsideration of the...

  16. Herbage production, nutritive value, and animal productivity within hardwood silvopasture, open and mixed pasture systems in Appalachia, United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for livestock food products are projected to increase dramatically through 2050. Increased livestock production capacity on marginal lands will be critical to meeting demand. A 5-year research effort was undertaken to evaluate lamb and sward productivity within open and hardwood silvopasture ...

  17. Development of red oak seedlings using plastic shelters on hardwood sites in West Virginia. Forest Service research paper (Final)

    SciTech Connect

    Smith, H.C.

    1993-04-01

    Plastic shelters were used to grow red oak seedlings on good-to-excellent Appalachian hardwood growing sites in north central West Virginia. Preliminary results indicate that shelters have the potential to stimulate development of red oak seedlingheight growth, especially if height growth continues once the seedling tops are above the 5-foot-tall shelters.

  18. 75 FR 1587 - Medford-Park Falls Ranger District, Chequamegon-Nicolet National Forest, Park Falls Hardwoods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-12

    ...The USDA Forest Service, Chequamegon-Nicolet National Forest, Medford-Park Falls Ranger District intends to prepare an Environmental Impact Statement (EIS) to document the analysis and disclose the environmental effects of proposed land management activities, and corresponding alternatives within the Park Falls Hardwoods project area. The primary purpose of this proposal is to implement......

  19. Methylation of microRNA genes regulates gene expression in bisexual flower development in andromonoecious poplar

    PubMed Central

    Song, Yuepeng; Tian, Min; Ci, Dong; Zhang, Deqiang

    2015-01-01

    Previous studies showed sex-specific DNA methylation and expression of candidate genes in bisexual flowers of andromonoecious poplar, but the regulatory relationship between methylation and microRNAs (miRNAs) remains unclear. To investigate whether the methylation of miRNA genes regulates gene expression in bisexual flower development, the methylome, microRNA, and transcriptome were examined in female and male flowers of andromonoecious poplar. 27 636 methylated coding genes and 113 methylated miRNA genes were identified. In the coding genes, 64.5% of the methylated reads mapped to the gene body region; by contrast, 60.7% of methylated reads in miRNA genes mainly mapped in the 5′ and 3′ flanking regions. CHH methylation showed the highest methylation levels and CHG showed the lowest methylation levels. Correlation analysis showed a significant, negative, strand-specific correlation of methylation and miRNA gene expression (r=0.79, P <0.05). The methylated miRNA genes included eight long miRNAs (lmiRNAs) of 24 nucleotides and 11 miRNAs related to flower development. miRNA172b might play an important role in the regulation of bisexual flower development-related gene expression in andromonoecious poplar, via modification of methylation. Gynomonoecious, female, and male poplars were used to validate the methylation patterns of the miRNA172b gene, implying that hyper-methylation in andromonoecious and gynomonoecious poplar might function as an important regulator in bisexual flower development. Our data provide a useful resource for the study of flower development in poplar and improve our understanding of the effect of epigenetic regulation on genes other than protein-coding genes. PMID:25617468

  20. Apoplast proteome reveals that extracellular matrix contributes to multi-stress response in poplar

    SciTech Connect

    Pechanova, Olga; Hsu, Chuan-Yu; Adams, Joshua P.; Pechan, Tibor; Vandervelde, Lindsay; Drnevich, Jenny; Jawdy, Sara; Adeli, Ardeshir; Suttle, Jeffrey; Lawrence, Amanda; Tschaplinski, Timothy J; Seguin, Armand; Yuceer, Cetin

    2010-01-01

    Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development. We report that poplar (Populus spp.) has evolved a systems level 'stress proteome' in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from P. deltoides, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen Melampsora. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast. These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.

  1. Energy partitioning and surface resistance of a poplar plantation in northern China

    NASA Astrophysics Data System (ADS)

    Kang, M.; Zhang, Z.; Noormets, A.; Fang, X.; Zha, T.; Zhou, J.; Sun, G.; McNulty, S. G.; Chen, J.

    2015-07-01

    Poplar (Populus sp.) plantations have been, on the one hand, broadly used in northern China for urban greening, combating desertification, as well as for paper and wood production. On the other hand, such plantations have been questioned occasionally for their possible negative impacts on water availability due to the higher water-use nature of poplar trees compared with other tree species in water-limited dryland regions. To further understand the acclimation of poplar species to semiarid environments and to evaluate the potential impacts of these plantations on the broader context of the region's water supply, we examine the variability of bulk resistance parameters and energy partitioning in a poplar (Populus euramericana cv. "74/76") plantation located in northern China over a 4-year period, encompassing both dry and wet conditions. The partitioning of available energy to latent heat flux (LE) decreased from 0.62 to 0.53 under mediated meteorological drought by irrigation applications. A concomitant increase in sensible heat flux (H) resulted in the increase of a Bowen ratio from 0.83 to 1.57. Partial correlation analysis indicated that surface resistance (Rs) normalized by leaf area index (LAI; Rs:LAI) increased by 50 % under drought conditions and was the dominant factor controlling the Bowen ratio. Furthermore, Rs was the main factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively). Rs was also a major regulator of the LE / LEeq ratio, which decreased from 0.81 in wet years to 0.68 in dry years. All physiological and bioclimatological metrics indicated that the water demands of the poplar plantation were greater than the amount available through precipitation, highlighting the poor match of a water-intensive species like poplar for this water-limited region.

  2. Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment.

    PubMed

    Dimitrova, Tsvetelina; Repmann, Frank; Raab, Thomas; Freese, Dirk

    2015-04-01

    Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg(-1) for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l(-1). The maximum cyanide content in willow and poplar leaves was 518 mg kg(-1) fresh weight (FW) and 148 mg kg(-1) FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l(-1) and for willow after 8 weeks of exposure-768 mg l(-1). Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides. PMID:25477029

  3. Some important physical properties of laminated veneer lumber (Lvl) made from oriental beech and Lombardy poplar

    NASA Astrophysics Data System (ADS)

    Kılıç, Murat

    2012-09-01

    This study examined some physical characteristics of laminated veneer lumber (LVL) obtained in different compositions from cut veneers of Oriental beech (Fagus Orientalis Lipsky) and Lombardy poplar (Populus nigra) with thicknesses of 4 mm and 5 mm. Five each beech and poplar trees were felled with this objective. The PVAc (Kleiberit 303) and PU (Bizon Timber PU-Max Express) types of adhesive were used in lamination. The air-dry and oven dry densities, cell wall density and porosity, the value of volume density, shrinkage in a tangential and radial direction and volume swelling amounts were determined by preparing the specimens in accordance with the standards.

  4. Inhibition of cytochromes P450 and the hydroxylation of 4-monochlorobiphenyl in whole poplar.

    PubMed

    Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L

    2013-07-01

    Cytochromes P450 (CYPs) are potential enzymes responsible for hydroxylation of many xenobiotics and endogenous chemicals in living organisms. It has been found that 4-monochlorobiphenyl (PCB3), mainly an airborne pollutant, can be metabolized to hydroxylated transformation products (OH-PCB3s) in whole poplars. However, the enzymes involved in the hydroxylation of PCB3 in whole poplars have not been identified. Therefore, two CYP suicide inhibitors, 1-aminobenzotriazole (ABT) and 17-octadecynoic acid (ODYA), were selected to probe the hydroxylation reaction of PCB3 in whole poplars in this work. Poplars (Populus deltoides × nigra, DN34) were exposed to PCB3 with or without inhibitor for 11 days. Results showed both ABT and ODYA can decrease the concentrations and yields of five OH-PCB3s in different poplar parts via the inhibition of CYPs. Furthermore, both ABT and ODYA demonstrated a dose-dependent relationship to the formation of OH-PCB3s in whole poplars. The higher the inhibitor concentrations, the lower the total yields of OH-PCB3s. For ABT spiked-additions, the total mass yield of five OH-PCB3s was inhibited by a factor of 1.6 times at an ABT concentration of 2.5 mg L(-1), 4.0 times at 12.5 mg L(-1), and 7.0 times at 25 mg L(-1). For the inhibitor ODYA, the total mass of five OH-PCB3s was reduced by 2.1 times compared to the control at an ODYA concentration of 2.5 mg L(-1). All results pointed to the conclusion that CYP enzymes were the agents which metabolized PCB3 to OH-PCB3s in whole poplars because suicide CYP inhibitors ABT and ODYA both led to sharp decreases of OH-PCB3s formation in whole poplars. A dose-response curve for each of the suicide inhibitors was developed. PMID:23320482

  5. Strong RNAi-inhibition of 4CL expression alters lignification, saccharification potential and productivity of field-grown poplar

    SciTech Connect

    Tuskan, Gerald A; Gunter, Lee E; Strauss, S

    2007-01-01

    RNAi-associated down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been proposed as a means for reducing lignin content in cell walls, and thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplars (Populus) we employed RNAi gene suppression of 4CL to generate 14 transgenic events and compared them to a non-transgenic control. After a two-year field trial we characterized the consequences of 4CL down-regulation on wood biochemistry and tree productivity. Lignin reductions correlated well with 4CL RNA expression, with a sharp decrease in lignin observed for RNA expression levels below ~50%. Lignin reductions greater than ~10% of the control value were associated with reduced productivity, decreased wood S/G (syringyl/guaiacyl) lignin monomer ratios, and increased incorporation of H-monomers (p-hydroxyphenyl) into cell walls. Strongly affected transgenic events were also characterized by patches of brown, discolored wood with about twice the extractive (complex polyphenolic) content of controls. There was no support for the hypothesis that reduced lignin would increase saccharification potential. The data presented suggest that a threshold of lignin reduction exists, beyond which there are large changes in wood chemistry and plant metabolism that affect productivity and potential ethanol yield.

  6. Changes in sulphur metabolism of grey poplar (Populus x canescens) leaves during salt stress: a metabolic link to photorespiration.

    PubMed

    Herschbach, Cornelia; Teuber, Markus; Eiblmeier, Monika; Ehlting, Barbara; Ache, Peter; Polle, Andrea; Schnitzler, Jörg-Peter; Rennenberg, Heinz

    2010-09-01

    The poplar hybrid Populus x canescens (syn. Populus tremula x Populus alba) was subjected to salt stress by applying 75 mM NaCl for 2 weeks in hydroponic cultures. Decreasing maximum quantum yield (Fv/Fm) indicated damage of photosystem II (PS II), which was more pronounced under nitrate compared with ammonium nutrition. In vivo staining with diaminobenzidine showed no accumulation of H(2)O(2) in the leaf lamina; moreover, staining intensity even decreased. But at the leaf margins, development of necrotic tissue was associated with a strong accumulation of H(2)O(2). Glutathione (GSH) contents increased in response to NaCl stress in leaves but not in roots, the primary site of salt exposure. The increasing leaf GSH concentrations correlated with stress-induced decreases in transpiration and net CO(2) assimilation rates at light saturation. Enhanced rates of photorespiration could also be involved in preventing reactive oxygen species formation in chloroplasts and, thus, in protecting PS II from damage. Accumulation of Gly and Ser in leaves indeed indicates increasing rates of photorespiration. Since Ser and Gly are both immediate precursors of GSH that can limit GSH synthesis, it is concluded that the salt-induced accumulation of leaf GSH results from enhanced photorespiration and is thus probably restricted to the cytosol. PMID:20516486

  7. The response of beetles to group selection harvesting in a southeastern bottomland hardwood forest.

    SciTech Connect

    Ulyshen, Michael, D.

    2005-04-01

    ABSTRACT The environmental protection and sustainable management of our remaining forests are increasingly important concerns. Group selection harvesting is an uneven-aged forest management practice that removes patches of desirable trees to create small openings mimicking natural disturbances. To determine the effects of this technique on beetles, malaise and pitfall traps were placed at the center, edge, and in the forest surrounding artificially created gaps of different size (0.13, 0.26, and 0.50 ha) and age (1 and 7 years) in a South Carolina bottomland hardwood forest. Beetles were generally more abundant and species rich in the centers of younger gaps than in the centers of older gaps or in the forest surrounding them. There were relatively few differences in the abundance and richness of beetles between old gaps and the surrounding forest but species composition differed considerably. These differences may be explained by the uneven distribution of various resources.

  8. Production of furfural from waste aqueous hemicellulose solution of hardwood over ZSM-5 zeolite.

    PubMed

    Gao, Hongling; Liu, Haitang; Pang, Bo; Yu, Guang; Du, Jian; Zhang, Yuedong; Wang, Haisong; Mu, Xindong

    2014-11-01

    This study aimed to produce furfural from waste aqueous hemicellulose solution of a hardwood kraft-based dissolving pulp production processing in a green method. The maximum furfural yield of 82.4% and the xylose conversion of 96.8% were achieved at 463K, 1.0g ZSM-5, 1.05g NaCl and organic solvent-to-aqueous phase ratio of 30:15 (V/V) for 3h. The furfural yield was just 51.5% when the same concentration of pure xylose solution was used. Under the optimized condition, furfural yield was still up to 67.1% even after the fifth reused of catalyst. Catalyst recycling study showed that ZSM-5 has a certain stability and can be efficiently reused. PMID:25266687

  9. Health Hazard Evaluation Report HETA 82-234-1602, Black River Hardwood Company, Kingstree, South Carolina

    SciTech Connect

    Salisbury, S.; Lybarger, J.

    1985-06-01

    A health-hazard evaluation was conducted at Black River Hardwood Company, Kingstree, South Carolina in July, 1982. The evaluation was requested by the owner to investigate a possible excess of cancer among employees. There was concern that the company's water supply had been contaminated by agricultural chemicals buried in an adjacent lot in 1974. Environmental sampling data at the disposal site obtained by the South Carolina Department of Health and Environmental Control (DHEC) were reviewed. The cancer cases involved the stomach, gastrointestinal tract, lungs, and head and neck. The authors conclude that a cancer hazard among the employees does not exist. They recommend continued monitoring of the company and community water supply and using bottled drinking water until a municipal water system is available.

  10. Crystalliferous Bacillus cereus group bacteria from a Maryland hardwood forest are dominated by psychrotolerant strains.

    PubMed

    Blackburn, Michael B; Martin, Phyllis A W; Kuhar, Daniel; Farrar, Robert R; Gundersen-Rindal, Dawn E

    2014-08-01

    Crystal-forming bacteria of the Bacillus cereus group were isolated from soil samples collected at different elevations within a mixed hardwood forest in central Maryland, and their phylogenetic relationships determined by multilocus sequence analysis. The vast majority of isolates obtained were associated with two phylogenetic groups known to be psychrotolerant, with very few isolates representing phylogenetic groups more typically associated with Bacillus thuringiensis. Isolates from the psychrotolerant groups were found to grow on solid media at 7 °C. Isolates of 11 highly related, novel sequence types (STs) from the psychrotolerant group that includes Bacillus weihenstephanensis were generally found at higher elevations, and were not associated with soils near streams. Isolates of two related STs from the second psychrotolerant group were nearly always found at the bottoms of ravines near streams, in areas abundant in earthworm castings. PMID:24985699

  11. Structure-function relationships in hardwood--insight from micromechanical modelling.

    PubMed

    de Borst, K; Bader, T K

    2014-03-21

    A micromechanical model is presented that predicts the stiffness of wood tissues in their three principal anatomical directions, across various hardwood species. The wood polymers cellulose, hemicellulose, and lignin, common to all wood tissues, serve as the starting point. In seven homogenisation steps, the stiffnesses of these polymers are linked to the macroscopic stiffness. The good agreement of model predictions and corresponding experimental data for ten different European and tropical species confirms the functionality and accuracy of the model. The model enables investigating the influence of individual microstructural features on the overall stiffness. This is exploited to elucidate the mechanical effects of vessels and ray cells. Vessels are shown to reduce the stiffness of wood at constant overall density. This supports that a trade-off exists between the hydraulic efficiency and the mechanical support in relation to the anatomical design of wood. Ray cells are shown to act as reinforcing elements in the radial direction. PMID:24365634

  12. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

    SciTech Connect

    Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

    2005-01-01

    Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  13. Open-grown crown radius of eleven bottomland hardwood species: Prediction and use in assessing stocking

    SciTech Connect

    Goelz, J.C.G.

    1996-08-01

    Equations were prepared to predict crown radius for eleven species of open-grown bottomland hardwood trees. Crown radius was predicted as a function of diameter at breast height (dbh) and as a function of dbh, total height, and crown ratio. Equations were prepared for individual species and species groups. Pecan has the largest crowns over a broad range of dbh. Eastern cottonwood has the smallest crowns for most levels of dbh. Sweetgum has relatively small crowns for trees of small dbh, but crown radius is comparable to most species at the largest dbh. The crown radius predictions may be used to calculate crown competition factor. B-lines of stocking may be calculated that represent a stand of one species as well as a mixed-species stand of any particular species proportion.

  14. Dead wood relative to slope severity in mesic loess bluff hardwood forests

    USGS Publications Warehouse

    Twedt, Daniel J.

    2012-01-01

    To aid in identification of land within Vicksburg National Military Park that was subjected to forest restoration during the 1930s, I evaluated the hypothesized relationships between maximum live tree diameter or dead wood (standing and down) and severity of slope. Disproportionate mortality among early-successional, pioneer tree species suggested maturation of pioneer upland hardwood forests. As such, input and decomposition of dead wood have likely approached equilibrium. Thus, I did not detect a useful predictive relationship between dead wood (standing or down) or maximum diameter of live trees and severity of slope. Lack of relationships between slope and large diameter trees or volume of dead wood resulted in an inability to evaluate former land use based on these parameters.

  15. DISTRIBUTION AND VOLATILIZATION OF ORGANIC COMPOUNDS FOLLOWING UPTAKE BY HYBRID POPLAR TREES. (R825549C060)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. Evaluating the tolerance of young hybrid poplar trees to recycled waters high in salinity and boron.

    PubMed

    Bañuelos, G S; LeDuc, D; Johnson, J

    2010-07-01

    The successful adoption of water recycling strategies in many arid regions will require crops able to tolerate poor-quality waters. We evaluated different clones for salt and boron (B) tolerance within each of seven genetically distinct genomic groups (e.g., deltoides, deltoides x nigra, trichocarpa x deltoides, trichocarpa x deltoides x maximowizcii, trichocarpa x deltoides x nigra, trichocarpa x nigra, trichocarpa x maximowizcii). During each evaluation period, different clones within each of the groups were irrigated with high sodium chloride (NaCl) salinity (i.e., 10-30 dS m(-1)) and B (i.e., 10 mg L(-1)) water up to a maximum of 150 days, for a 4-year testing period under micro-field plot conditions. Excessive accumulation (up to 6%) of chloride (Cl) likely caused toxicity symptoms (necrosis of the leaves) observed in the less tolerant clones, while leaf B concentrations rarely exceeded 300 mg kg(-1) DM in any clone. Increased soil salinity likely hindered the uptake of B by the clones. Our results show that a wide range of selected Populus clones, of parentage trichocarpa x nigra, followed by deltoides x nigra show potential salt and B tolerance as young trees to recycled waters high in salinity and B. PMID:21166286

  17. Crop Response to Hybrid Poplar Alternative Soilless Substrate Component for Pacific Northwest Ornamental Container Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Douglas fir bark (DFB) is the primary component used in soilless substrate to grow woody ornamental plants in the Pacific Northwest. Bark is a by-product of the timber industry and is used for landscape mulch, a soilless substrate component, or bio-energy. The decline in the housing market and rise ...

  18. Effects of earthworm invasion on plant species richness in northern hardwood forests.

    PubMed

    Holdsworth, Andrew R; Frelich, Lee E; Reich, Peter B

    2007-08-01

    The invasion of non-native earthworms (Lumbricus spp.) into a small number of intensively studied stands of northern hardwood forest has been linked to declines in plant diversity and the local extirpation of one threatened species. It is unknown, however, whether these changes have occurred across larger regions of hardwood forests, which plant species are most vulnerable, or with which earthworm species such changes are associated most closely. To address these issues we conducted a regional survey in the Chippewa and Chequamegon national forests in Minnesota and Wisconsin (U.S.A.), respectively. We sampled earthworms, soils, and vegetation, examined deer browse in 20 mature, sugar-maple-dominated forest stands in each national forest, and analyzed the relationship between invasive earthworms and vascular plant species richness and composition. Invasion by Lumbricus was a strong indicator of reduced plant richness in both national forests. The mass of Lumbricus juveniles was significantly and negatively related to plant-species richness in both forests. In addition, Lumbricus was a significant factor affecting plant richness in a full model that included multiple variables. In the Chequamegon National Forest earthworm mass was associated with higher sedge cover and lower cover of sugar maple seedlings and several forb species. The trends were similar but not as pronounced in Chippewa, perhaps due to lower deer densities and different earthworm species composition. Our results provide regional evidence that invasion by Lumbricus species may be an important mechanism in reduced plant-species richness and changes in plant communities in mature forests dominated by sugar maples. PMID:17650250

  19. Hardwood tree growth after eight years on brown and gray mine soils in west virginia.

    PubMed

    Wilson-Kokes, L; Emerson, P; Delong, C; Thomas, C; Skousen, J

    2013-09-01

    Surface coal mining in Appalachia disturbs hundreds of hectares of land every year with the removal of valuable and ecologically diverse eastern deciduous forests. After the passage of the Surface Mining Control and Reclamation Act in 1977, coal mine operators began planting a variety of grasses and legumes as a fast and economical way to reestablish a permanent vegetative cover to meet erosion and site stabilization requirements. However, soil compaction and competitive forage species have arrested the recolonization of native hardwood tree species on these reclaimed sites. Three 2.8-ha demonstration plots were established at Catenary Coal's Samples Mine in Kanawha County, West Virginia, of weathered brown sandstone and unweathered gray sandstone. Half of each plot was compacted. Each plot was hydroseeded with a low-competition herbaceous cover and planted with 11 hardwood tree species. After eight growing seasons, average tree volume index was nearly 10 times greater for trees grown in the brown sandstone treatments, 3853 cm, compared with 407 cm in gray sandstone. Trees growing on compacted treatments had a lower mean volume index, 2281 cm, than trees growing on uncompacted treatments, 3899 cm. Average pH of brown sandstone was 5.2 to 5.7, while gray sandstone was 7.9. The gray sandstone had much lower fine soil fraction (<2-mm) content (40%) than brown sandstone (70%), which influenced nutrient- and water-holding capacity. Brown sandstone showed significantly greater tree growth and survival and at this stage is a more suitable topsoil substitute than gray sandstone on this site. PMID:24216413

  20. Kinetics of acid hydrolysis of hardwood in a continuous plug flow reactor

    SciTech Connect

    Kwarteng, I.K.

    1983-01-01

    This thesis was undertaken to investigate the kinetics of dilute acid catalyzed hydrolysis of hardwood in an isothermally operated continuous plug flow reactor at steady state. Sulphuric acid catalyst concentration ranged from 0.05 to 2.5 wt% and the reaction temperatures were between 160/sup 0/C and 265/sup 0/C. The residence time was limited to between 0.1 and 0.5 minutes while the wood slurry concentration varied from 5 wt% to 10 wt%. Kinetic models, as functions of the reaction conditions, were obtained for the hemicelluloses (xylan) to xylose, xylose to furfural, fufural decomposition, and cellulose (glucan) to glucose reactions. Numerical solutions (Runge-Kutta Methods) to a system of first order differential equations which provided a composite description of the kinetic model for furfural production from xylan were also presented. Furfural yields of up to 87% were verified. Xylose appearance from hardwood xylan could be modelled by a sequence of two irreversible consecutive first-order reactions. The proposed model, however, underestimated xylose yields at the conditions of quantitative yields (1 wt% 2 wt%, 0.25 minutes and 190/sup 0/C to 210/sup 0/C). For the cellulose to glucose reaction, a similar model with different parameters produced yields of up to 56% at 240/sup 0/C to 260/sup 0/C. Two approaches for the carbohydrate recovery and utilization in acid hydrolysis were proposed as follows. 1) Two-stage hydrolysis: in this mode, the first stage is at the conditions for maximum xylose recovery. This is then followed by a second-stage hydrolysis at higher temperatures for glucose recovery. 2) Single-stage hydrolysis: since the conditions for high furfural yields coincide with those for glucose, a single stage hydrolysis for their simultaneous recovery can also be achieved.

  1. Respiratory Symptoms and Lung Function in Never-Smoking Male Workers Exposed To Hardwood Dust

    PubMed Central

    Bislimovska, Dragana; Petrovska, Sunchica; Minov, Jordan

    2015-01-01

    BACKGROUND: Results from many studies suggest that workplace exposure to organic dust may lead to adverse respiratory effects in exposed workers. AIM: In order to assess the respiratory effects of the workplace exposure to hardwood dust we performed a cross-sectional study of never-smoking male workers employed in parquet manufacture and never-smoking male office workers as a control. MATERIAL AND METHODS: We performed a cross-sectional study including 37 never-smoking male workers employed in parquet manufacture and an equal number of never-smoking male office workers studied as a control. Evaluation of examined subjects included completion of a questionnaire for respiratory symptoms in the last 12 months and baseline spirometry performed according to the actual recommendations. RESULTS: We found a higher prevalence of respiratory symptoms in parquet manufacturers than in office workers with significant difference for cough and phlegm. Majority of the respiratory symptoms in the parquet manufacturers were work-related. The mean values of all spirometric parameters with exception of forced ventilatory capacity (FVC) were significantly lower in the parquet manufacturers as compared to their mean values in the office workers. We found close relationship between both the prevalence of respiratory symptoms and the reduction of spirometric parameters in the parquet manufacturers and the duration of the workplace exposure to wood dust. CONCLUSION: Our data suggest that workplace exposure to hardwood dust may lead to adverse respiratory effects indicating the need of adequate preventive measures in order to protect the respiratory health of exposed workers. PMID:27275278

  2. Ecotone resilience in a coastal system of mangroves and hardwood hammocks

    NASA Astrophysics Data System (ADS)

    Turtora, M.; DeAngelis, D. L.; Teh, S. Y.; Jiang, J.

    2013-12-01

    Initial sea-level rise effects on low-lying coastline vegetation will likely result from an increase in the frequency and magnitude of storm surges. Feedbacks between vegetation and vadose zone pore-water salinity likely result in complex interactions between halophytic and glycophytic vegetation due to differential adaptive responses. In coastal Everglades National Park, relatively impermeable marl soils distributed in a ridge and swale topography overlie highly permeable karst limestone saturated with high salinity water. Soil salinity dynamics reflect pronounced rainfall seasonality. A model of MANgrove and hardwood HAMmock competition (MANHAM) has been integrated with a variable density Saturated/Unsaturated groundwater TRAnsport model (SUTRA). The combined model (MANTRA) is being used to estimate likely vegetative responses to various scenarios of changing sea-level and precipitation patterns. The mangrove/hammock regime is characterized by the occurrence of sharp ecotones over relatively shallow elevation gradients that may be maintained by a vegetation switch. A disturbance such as an input of salinity from a storm surge could upset this meta-stable boundary, leading to a regime shift of halophytic vegetation inland. MANTRA allows simulation of the interaction of vegetation with subsurface salinity dynamics while examining the sensitivity of the vegetation switch to relevant variables. The response of the halophyte/glycophyte system to storm surge overwash is predicted to depend on factors such as amount and duration of the salinity increase in the soil, the water-table elevation and salinity of the groundwater, the amount and timing of precipitation, runoff and infiltration, the extent of wind induced storm damage, and the amount of mangrove propagules that are washed into the hardwood hammock. In addition, direct mortality of hammock vegetation and increasing floating dispersal of mangrove propagules due to storm surge increase the likelihood of a regime

  3. Research on the pyrolysis of hardwood in an entrained bed process development unit

    SciTech Connect

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O'Neil, D.J. . Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  4. Expression of Multiple Resistance Genes Enhances Tolerance to Environmental Stressors in Transgenic Poplar (Populus × euramericana ‘Guariento’)

    PubMed Central

    Su, Xiaohua; Chu, Yanguang; Li, Huan; Hou, Yingjie; Zhang, Bingyu; Huang, Qinjun; Hu, Zanmin; Huang, Rongfeng; Tian, Yingchuan

    2011-01-01

    Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana ‘Guariento’) harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional

  5. Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings▿†

    PubMed Central

    Hur, Moonsuk; Kim, Yongho; Song, Hae-Ryong; Kim, Jong Min; Choi, Young Im; Yi, Hana

    2011-01-01

    The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizosphere of genetically modified (GM) versus wild-type (WT) poplar was conducted on trees at different growth stages (i.e., the rhizospheres of 1.5-, 2.5-, and 3-year-old poplars) that were cultivated on contaminated soils together with nonplanted control soil. Based on the results of DNA pyrosequencing, poplar type and growth stages were associated with directional changes in the structure of the microbial community. The rate of change was faster in GM poplars than in WT poplars, but the microbial communities were identical in the 3-year-old poplars. This phenomenon may arise because of a higher rate and greater extent of metal accumulation in GM poplars than in naturally occurring plants, which resulted in greater changes in soil environments and hence the microbial habitat. PMID:21890678

  6. Indian Culture Program. Poplar River School No. 050, Negginan, P.O.

    ERIC Educational Resources Information Center

    McKay, Rosemary; And Others

    Developed by teachers at the Poplar River School Number 050 (Negginan, Ontario, Canada), this curriculum guide presents a cultural expansion program for: (1) kindergarten students (a unit on community study including such topics as: food, shelter, clothing, medicine, transportation and a unit on "other" Indian cultures "by way of legends"); (2)…

  7. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome

    PubMed Central

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-01-01

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement. PMID:26755604

  8. Metabolic Responses of Poplar to Apripona germari (Hope) as Revealed by Metabolite Profiling.

    PubMed

    Wang, Lijuan; Qu, Liangjian; Zhang, Liwei; Hu, Jianjun; Tang, Fang; Lu, Mengzhu

    2016-01-01

    Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass spectrometry (GC-TOF/MS). It was found that, four days after feeding (stage I), A. germari infection brought about changes in various metabolites, such as phenolics, amino acids and sugars in both bark and xylem. Quinic acid, epicatechin, epigallocatechin and salicin might play a role in resistance response in bark, while coniferyl alcohol, ferulic acid and salicin contribute resistance in xylem. At feeding stages II when the larvae fed for more than one month, fewer defensive metabolites were induced, but levels of many intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were reduced, especially in xylem. These results suggested that the defense strategies against A. germari might depend mainly on the early defense responses in poplar. In addition, it was found that bark and xylem in infected trees accumulated higher levels of salicylic acid and 4-aminobutyric acid, respectively, these tissues displaying a direct and systemic reaction against A. germari. However, the actual role of the two metabolites in A. germari-induced defense in poplar requires further investigation. PMID:27331808

  9. Metabolic Responses of Poplar to Apripona germari (Hope) as Revealed by Metabolite Profiling

    PubMed Central

    Wang, Lijuan; Qu, Liangjian; Zhang, Liwei; Hu, Jianjun; Tang, Fang; Lu, Mengzhu

    2016-01-01

    Plants have developed biochemical responses to adapt to biotic stress. To characterize the resistance mechanisms in poplar tree against Apripona germari, comprehensive metabolomic changes of poplar bark and xylem in response to A. germari infection were examined by gas chromatography time-of-flight mass spectrometry (GC–TOF/MS). It was found that, four days after feeding (stage I), A. germari infection brought about changes in various metabolites, such as phenolics, amino acids and sugars in both bark and xylem. Quinic acid, epicatechin, epigallocatechin and salicin might play a role in resistance response in bark, while coniferyl alcohol, ferulic acid and salicin contribute resistance in xylem. At feeding stages II when the larvae fed for more than one month, fewer defensive metabolites were induced, but levels of many intermediates of glycolysis and the tricarboxylic acid (TCA) cycle were reduced, especially in xylem. These results suggested that the defense strategies against A. germari might depend mainly on the early defense responses in poplar. In addition, it was found that bark and xylem in infected trees accumulated higher levels of salicylic acid and 4-aminobutyric acid, respectively, these tissues displaying a direct and systemic reaction against A. germari. However, the actual role of the two metabolites in A. germari-induced defense in poplar requires further investigation. PMID:27331808

  10. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.

    PubMed

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-02-23

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement. PMID:26755604

  11. Association Analysis Identifies Melampsora ×columbiana Poplar Leaf Rust Resistance SNPs

    PubMed Central

    La Mantia, Jonathan; Klápště, Jaroslav; El-Kassaby, Yousry A.; Azam, Shofiul; Guy, Robert D.; Douglas, Carl J.; Mansfield, Shawn D.; Hamelin, Richard

    2013-01-01

    Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05) with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca2+/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism. PMID:24236018

  12. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2011-08-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar, modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed lines (line RA22), respectively. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3 % of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  13. Isoprene in poplar emissions: effects on new particle formation and OH concentrations

    NASA Astrophysics Data System (ADS)

    Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

    2012-01-01

    Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m-2 s-1) in isoprene emission-repressed plants (line RA22), respectively. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

  14. Responses of energy partitioning and surface resistance to drought in a poplar plantation in northern China

    NASA Astrophysics Data System (ADS)

    Kang, M.; Zhang, Z.; Noormets, A.; Fang, X.; Zha, T.; Zhou, J.; Sun, G.; McNulty, S.; Chen, J.

    2015-01-01

    Poplar (Populus sp.) plantations have been used broadly for combating desertification, urban greening, and paper and wood production in northern China. However, given the high water use by the species and the regional dry environment, the long-term sustainability of these plantations needs to be evaluated. Currently, the understanding of energy partitioning and canopy resistance to water vapor and CO2 in poplar plantations is limited, impeding an accurate assessment of their true ecosystem functions. This study examined the variability of canopy bulk resistance parameters and energy partitioning over a four-year period encompassing both dry and wet conditions in a poplar (Populus euramericana CV. "74 / 76") plantation ecosystem located in northern China. Available energy (Net radiation Rn minus Soil Heat Flux, G) partitioning to latent (LE) and sensible (H) heat was responsive to climatological drought, with LE/(Rn-G) ranging from 62% in wet years (e.g. 2007 and 2008) to 53% in dry years (e.g. 2006 and 2009), and H/(Rn-G) from 25 to 33% between wet and dry years. Correspondingly, the Bowen ratio (β=H/LE) were 0.83 and 1.57. Surface resistance (Rs) had the greatest response to drought (+43%), but the aerodynamic and climatological resistances did not change significantly (p > 0.05). Partial correlation analysis indicated that Rs was the dominant factor in controlling the Bowen ratio. Furthermore, Rs was the major factor controlling LE during the growing season, even in wet years, as indicated by the decoupling coefficient (Ω = 0.45 and 0.39 in wet and dry years, respectively), and the LE / LEeq ratio ranged from 0.81 and 0.68 in wet and dry years, respectively. In general, the dry surface conditions dominated in this poplar plantation ecosystem regardless of soil water availability suggesting that fast-growing and water use-intensive species like poplar plantations are poorly adapted for the water limited region.

  15. Forest conversion to poplar plantation in a Lombardy floodplain (Italy): effects on soil organic carbon stock

    NASA Astrophysics Data System (ADS)

    Ferré, C.; Comolli, R.; Leip, A.; Seufert, G.

    2014-11-01

    Effects of forest conversion to poplar plantation on soil organic carbon (SOC) stocks were investigated by sampling paired plots in an alluvial area of the Ticino River in Northern Italy. According to land registers and historical aerial photographs, the two sites were part of a larger area of a 200 yr old natural forest that was partly converted to poplar plantation in 1973. The soil sampling of three layers down to a depth of 100 cm was performed at 90 and 70 points in the natural forest (NF) and in the nearby poplar plantation (PP) respectively. The substitution of the natural forest with the poplar plantation strongly modified soil C stock down to a depth of 55 cm, although the management practices at PP were not intensive. After calculation of equivalent soil masses and of SOC stocks in individual texture classes, the comparison of C stocks showed an overall decrease in SOC of 5.7 kg m-2 or 40% in consequence of 37 years of poplar cultivation. Our case study provides further evidence that (i) spatial heterogeneity of SOC is an important feature in paired plot studies requiring a careful sampling strategy and high enough number of samples; (ii) land use changes through tillage are creating a more homogeneous spatial structure of soil properties and may require the application of dedicated spatial statistics to tackle eventual problems of pseudo-replicates and auto-correlation; (iii) short rotation forests are not properly represented in current reporting schemes for changes of SOC after land use change and may better be considered as cropland.

  16. The Nitrate Transporter (NRT) Gene Family in Poplar

    PubMed Central

    Bai, Hua; Euring, Dejuan; Volmer, Katharina; Janz, Dennis; Polle, Andrea

    2013-01-01

    Nitrate is an important nutrient required for plant growth. It also acts as a signal regulating plant development. Nitrate is actively taken up and transported by nitrate transporters (NRT), which form a large family with many members and distinct functions. In contrast to Arabidopsis and rice there is little information about the NRT family in woody plants such as Populus. In this study, a comprehensive analysis of the Populus NRT family was performed. Sixty-eight PtNRT1/PTR, 6 PtNRT2, and 5 PtNRT3 genes were identified in the P. trichocarpa genome. Phylogenetic analysis confirmed that the genes of the NRT family are divided into three clades: NRT1/PTR with four subclades, NRT2, and NRT3. Topological analysis indicated that all members of PtNRT1/PTR and PtNRT2 have 8 to 12 trans-membrane domains, whereas the PtNRT3 proteins have no or up to two trans-membrane domains. Four PtNRT3 members were predicted as secreted proteins. Microarray analyses revealed tissue-specific expression patterns of PtNRT genes with distinct clusters of NRTs for roots, for the elongation zone of the apical stem segment and the developing xylem and a further cluster for leaves, bark and wood. A comparison of different poplar species (P. trichocarpa, P. tremula, P. euphratica, P. fremontii x P. angustifolia, and P. x canescens) showed that the tissue-specific patterns of the NRT genes varied to some extent with species. Bioinformatic analysis of putative cis-regulatory elements in the promoter regions of PtNRT family retrieved motifs suggesting the regulation of the NRT genes by N metabolism, by energy and carbon metabolism, and by phytohormones and stress. Multivariate analysis suggested that the combination and abundance of motifs in distinct promoters may lead to tissue-specificity. Our genome wide analysis of the PtNRT genes provides a valuable basis for functional analysis towards understanding the role of nitrate transporters for tree growth. PMID:23977227

  17. Results of a workshop concerning impacts of various activities on the functions of bottomland hardwoods

    USGS Publications Warehouse

    Roelle, James E.; Auble, Gregor T.; Hamilton, David B.; Horak, Gerald C.; Johnson, Richard L.; Segelquist, Charles A.

    1987-01-01

    Under Section 404 of the Clean Water Act, the U.S. Environmental Protection Agency (EPA) has regulatory responsibilities related to the discharge of dredged or fill material into the Nation’s waters. In addition to its advisory role in the U.S. Army Corps of Engineers' permit program, EPA has a number of specific authorities, including formulation of the Section 404(b)(1) guidelines, use of Section 404(c) to prohibit disposal at particular sites, and enforcement actions for unauthorized discharges. A number of recent court cases focus on the geographic scope of Section 404 jurisdiction in potential bottomland hardwood (BLH) wetlands and the nature of landclearing activities in these areas that require a permit under Section 404. Accordingly, EPA needs to establish the scientific basis for implementing its responsibilities under Section 404 in bottomland hardwoods. EPA is approaching this task through a series of workshops designed to provide current scientific information on bottomland hardwoods and to organize that information in a manner pertinent to key policy questions. The first two workshops in the series were originally conceived as technically oriented meetings that would provide the information necessary to develop policy options at the third workshop. More specifically, the first workshop was designed to examine a zonation concept as a means of characterizing different BLH communities and describing variations in their functions along a soil moisture gradient. The second workshop was perceived as an attempt to evaluate the impacts of various activities on those functions. However, one conclusion of the first workshop, which was held in December 1984 in St. Francisville, Louisiana, was that the zonation approach does not describe the variability in the functions performed by BLH ecosystems sufficiently well to allow its use as the sole basis for developing a regulatory framework. That is, factors other than zone were considered critical for an effective

  18. Enzymatic hydrolysis of hardwood and softwood harvest residue fibers released by sulfur dioxide-ethanol-water fractionation.

    PubMed

    Yamamoto, Minna; Iakovlev, Mikhail; Bankar, Sandip; Tunc, Mehmet Sefik; van Heiningen, Adriaan

    2014-09-01

    The enzymatic hydrolysis of hardwood and softwood harvest residues treated by SO2-ethanol-water (SEW) fractionation was studied. The target was to convert these fibers with high yield into glucose monomers which could be further converted into biofuel by a subsequent fermentation stage. Hardwood biomass residues were efficiently digested at low enzyme dosage (5 FPU/g cellulose) whereas the softwood residues required notably higher enzyme dosage (20 FPU) for sufficient conversion. However, cellulase dosage of softwood could be reduced mannanase supplementation. Especially the high lignin content of softwood biomass pulps impairs the digestibility and thereby, improved delignification could notably enhance the hydrolysis yields. It was shown that inferior delignification of SW biomass is due to persistent polyphenolic acids present in coniferous bark, whereas no evidence of the negative effect of inorganics and acetone extractives was observed. Additionally, SW hydrolyzate was successfully converted into a mixture of butanol, acetone and ethanol through ABE fermentation. PMID:25022728

  19. Restoration of Upland Hardwood Tree Species on the Formerly Cultivated Soils in the Coastal Plain of South Carolina

    SciTech Connect

    Jones, R.H.; Waldrop, T.A.

    2001-08-03

    The authors studied various approaches to restore upland hardwood species to formerly cultivated soils at the SRS. Studies with direct seedling were largely a failure and resulted in very low rates of establishment. Failure was a result of predation and drought. Growth and survival of planted oaks, dogwood and pine did not vary between hardwood overstory and pine overstory conditions. Soil trenching in a forty year old loblolly stand demonstrated dramatic increases in growth of planted oaks and dogwood. When compared, survival is similar if not slightly better when seedlings are planted in the understory of canopies vs. clearcuts. However, growth is better in recent clearcuts for dogwood and white oaks. Hickory does better underplanted.

  20. CHARACTERIZATION OF MERCURY CONTAMINATION AT THE EAST FORK POPLAR CREEK SITE, OAK RIDGE, TENNESSEE: A CASE STUDY

    EPA Science Inventory

    Historic accidental release of mercury-contaminated material associated with nuclear weapons production at East Fork Poplar Creek (EFPC) resulted in stream and floodplain contamination. he EFPC is designated as an Oak Ridge Reservation (ORR) operable unit under the Comprehensive ...

  1. Genotypic variations in the dynamics of metal concentrations in poplar leaves: a field study with a perspective on phytoremediation.

    PubMed

    Pottier, Mathieu; García de la Torre, Vanesa S; Victor, Cindy; David, Laure C; Chalot, Michel; Thomine, Sébastien

    2015-04-01

    Poplar is commonly used for phytoremediation of metal polluted soils. However, the high concentrations of trace elements present in leaves may return to soil upon leaf abscission. To investigate the mechanisms controlling leaf metal content, metal concentrations and expression levels of genes involved in metal transport were monitored at different developmental stages on leaves from different poplar genotypes growing on a contaminated field. Large differences in leaf metal concentrations were observed among genotypes. Whereas Mg was remobilized during senescence, Zn and Cd accumulation continued until leaf abscission in all genotypes. A positive correlation between Natural Resistance Associated Macrophage Protein 1 (NRAMP1) expression levels and Zn bio-concentration factors was observed. Principal component analyses of metal concentrations and gene expression levels clearly discriminated poplar genotypes. This study highlights a general absence of trace element remobilization from poplar leaves despite genotype specificities in the control of leaf metal homeostasis. PMID:25622297

  2. Poplar breeding and testing strategies in the NC US: Demonstration of potential yield and consideration of future research needs.

    SciTech Connect

    Riemenschneider, Don; Berguson, William E; Dickmann, Don; Hall, Richard

    2004-06-30

    The objective of this project was to extend previous poplar breeding and selection in the NC US by implementing a regional testing system with multiple test locations in Minnesota, Iowa, Wisconsin and Michigan.

  3. Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

    SciTech Connect

    Nelson, E.A.

    2000-01-05

    The Savannah River Swamp is a 3020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy's Savannah River Site (SRS) near Aiken, SC. Historically the swamp consisted of approximately 50 percent bald cypress-water tupelo stands, 40 percent mixed bottomland hardwood stands, and 10 percent shrub, marsh, and open water. Creek corridors were typical of Southeastern bottomland hardwood forests. The hydrology was controlled by flooding of the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream dams have caused some alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950's. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. Flow in one of the tributaries, Pen Branch, was typically 0.3 m3 s-1 (10-20) cfs prior to reactor pumping and 11.0 m3 s-1 (400 cfs) during pumping. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 65 degrees C. The nearly continuous flooding of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. In the years since pumping was reduced, early succession has begun in some affected areas. Most of this has been herbs, grasses, and shrubs. Areas that have seedlings are generally willow

  4. Segregating the Effects of Seed Traits and Common Ancestry of Hardwood Trees on Eastern Gray Squirrel Foraging Decisions

    PubMed Central

    Sundaram, Mekala; Willoughby, Janna R.; Lichti, Nathanael I.; Steele, Michael A.; Swihart, Robert K.

    2015-01-01

    The evolution of specific seed traits in scatter-hoarded tree species often has been attributed to granivore foraging behavior. However, the degree to which foraging investments and seed traits correlate with phylogenetic relationships among trees remains unexplored. We presented seeds of 23 different hardwood tree species (families Betulaceae, Fagaceae, Juglandaceae) to eastern gray squirrels (Sciurus carolinensis), and measured the time and distance travelled by squirrels that consumed or cached each seed. We estimated 11 physical and chemical seed traits for each species, and the phylogenetic relationships between the 23 hardwood trees. Variance partitioning revealed that considerable variation in foraging investment was attributable to seed traits alone (27–73%), and combined effects of seed traits and phylogeny of hardwood trees (5–55%). A phylogenetic PCA (pPCA) on seed traits and tree phylogeny resulted in 2 “global” axes of traits that were phylogenetically autocorrelated at the family and genus level and a third “local” axis in which traits were not phylogenetically autocorrelated. Collectively, these axes explained 30–76% of the variation in squirrel foraging investments. The first global pPCA axis, which produced large scores for seed species with thin shells, low lipid and high carbohydrate content, was negatively related to time to consume and cache seeds and travel distance to cache. The second global pPCA axis, which produced large scores for seeds with high protein, low tannin and low dormancy levels, was an important predictor of consumption time only. The local pPCA axis primarily reflected kernel mass. Although it explained only 12% of the variation in trait space and was not autocorrelated among phylogenetic clades, the local axis was related to all four squirrel foraging investments. Squirrel foraging behaviors are influenced by a combination of phylogenetically conserved and more evolutionarily labile seed traits that is

  5. Segregating the Effects of Seed Traits and Common Ancestry of Hardwood Trees on Eastern Gray Squirrel Foraging Decisions.

    PubMed

    Sundaram, Mekala; Willoughby, Janna R; Lichti, Nathanael I; Steele, Michael A; Swihart, Robert K

    2015-01-01

    The evolution of specific seed traits in scatter-hoarded tree species often has been attributed to granivore foraging behavior. However, the degree to which foraging investments and seed traits correlate with phylogenetic relationships among trees remains unexplored. We presented seeds of 23 different hardwood tree species (families Betulaceae, Fagaceae, Juglandaceae) to eastern gray squirrels (Sciurus carolinensis), and measured the time and distance travelled by squirrels that consumed or cached each seed. We estimated 11 physical and chemical seed traits for each species, and the phylogenetic relationships between the 23 hardwood trees. Variance partitioning revealed that considerable variation in foraging investment was attributable to seed traits alone (27-73%), and combined effects of seed traits and phylogeny of hardwood trees (5-55%). A phylogenetic PCA (pPCA) on seed traits and tree phylogeny resulted in 2 "global" axes of traits that were phylogenetically autocorrelated at the family and genus level and a third "local" axis in which traits were not phylogenetically autocorrelated. Collectively, these axes explained 30-76% of the variation in squirrel foraging investments. The first global pPCA axis, which produced large scores for seed species with thin shells, low lipid and high carbohydrate content, was negatively related to time to consume and cache seeds and travel distance to cache. The second global pPCA axis, which produced large scores for seeds with high protein, low tannin and low dormancy levels, was an important predictor of consumption time only. The local pPCA axis primarily reflected kernel mass. Although it explained only 12% of the variation in trait space and was not autocorrelated among phylogenetic clades, the local axis was related to all four squirrel foraging investments. Squirrel foraging behaviors are influenced by a combination of phylogenetically conserved and more evolutionarily labile seed traits that is consistent with a weak

  6. Constitutive expression of the Poplar FD-like basic leucine zipper transcription factor alters growth and bud development.

    PubMed

    Parmentier-Line, Cécile M; Coleman, Gary D

    2016-01-01

    In poplar, the CO/FT regulatory module mediates seasonal growth cessation. Although FT interacts with the basic leucine zipper transcription factor FD, surprisingly little is known about the possible role of FD in bud development and growth cessation in trees. In this study, we examined the expression and localization of the poplar FD homolog, PtFD1, during short-day (SD)-induced bud development, and the consequences of overexpressing PtFD1 on bud development and shoot growth. PtFD1 was primarily expressed in apical and axillary buds and exhibited a transient increase in expression during the initial stages of SD-induced bud development. This transient increase declined with continued SD treatment. When PtFD1 was overexpressed in poplar, SD-induced growth cessation and bud formation were abolished. PTFD1 overexpression also resulted in precocious flowering of juvenile plants in long-day (LD) photoperiods. Because the phenotypes associated with overexpression of PtFD1 are similar to those observe when poplar FT1 is overexpressed (Science, 312, 2006, 1040), the expression and diurnal patterns of expression of both poplar FT1 and FT2 were characterized in PtFD1 overexpression poplars and found to be altered. DNA microarray analysis revealed few differences in gene expression between PtFD1 overexpressing poplars in LD conditions while extensive levels of differential gene expression occur in SD-treated plants. These results enforce the connection between the regulation of flowering and the regulation of growth cessation and bud development in poplar. PMID:25915693

  7. The Atlantic-Mediterranean watershed, river basins and glacial history shape the genetic structure of Iberian poplars.

    PubMed

    Macaya-Sanz, D; Heuertz, M; López-de-Heredia, U; De-Lucas, A I; Hidalgo, E; Maestro, C; Prada, A; Alía, R; González-Martínez, S C

    2012-07-01

    Recent phylogeographic studies have elucidated the effects of Pleistocene glaciations and of Pre-Pleistocene events on populations from glacial refuge areas. This study investigates those effects in riparian trees (Populus spp.), whose particular features may convey enhanced resistance to climate fluctuations. We analysed the phylogeographic structure of 44 white (Populus alba), 13 black (Populus nigra) and two grey (Populus x canescens) poplar populations in the Iberian Peninsula using plastid DNA microsatellites and sequences. We also assessed fine-scale spatial genetic structure and the extent of clonality in four white and one grey poplar populations using nuclear microsatellites and we determined quantitative genetic differentiation (Q(ST) ) for growth traits in white poplar. Black poplar displayed higher regional diversity and lower differentiation than white poplar, reflecting its higher cold-tolerance. The dependence of white poplar on phreatic water was evidenced by strong differentiation between the Atlantic and Mediterranean drainage basins and among river basins, and by weaker isolation by distance within than among river basins. Our results suggest confinement to the lower river courses during glacial periods and moderate interglacial gene exchange along coastlines. In northern Iberian river basins, white poplar had lower diversity, fewer private haplotypes and larger clonal assemblies than in southern basins, indicating a stronger effect of glaciations in the north. Despite strong genetic structure and frequent asexual propagation in white poplar, some growth traits displayed adaptive divergence between drainage and river basins (Q(ST) >F(ST)), highlighting the remarkable capacity of riparian tree populations to adapt to regional environmental conditions. PMID:22624974

  8. Analyzing the impact of climate and management factors on the productivity and soil carbon sequestration of poplar plantations.

    PubMed

    Wang, Dan; Fan, Jiazhi; Jing, Panpan; Cheng, Yong; Ruan, Honghua

    2016-01-01

    It is crucial to investigate how climate and management factors impact poplar plantation production and soil carbon sequestration interactively. We extracted above-ground net primary production (ANPP), climate and management factors from peer-reviewed journal articles and analyzed impact of management factor and climate on the mean annual increment (MAI) of poplar ANPP statistically. Previously validated mechanistic model (ED) is used to perform case simulations for managed poplar plantations under different harvesting rotations. The meta-analysis indicate that the dry matter MAI was 6.3 Mg ha(-1) yr(-1) (n=641, sd=4.9) globally, and 5.1 (n=292, sd=4.0), 8.1 (n=224, sd=4.7) and 4.4 Mg ha(-1) yr(-1) (n=125, sd=3.2) in Europe, the US and China, respectively. Poplar MAI showed a significant response to GDD, precipitation and planting density and formed a quadratic relationship with stand age. The low annual production for poplar globally was probably caused by suboptimal water availability, rotation length and planting density. SEM attributes the variance of poplar growth rate more to climate than to management effects. Case simulations indicated that longer rotation cycle significantly increased soil carbon storage. Findings of this work suggests that management factor of rotation cycle alone could have dramatic impact on the above ground growth, as well as on the soil carbon sequestration of poplar plantations and will be helpful to quantify the long-term carbon sequestration through short rotation plantation. The findings of this study are useful in guiding further research, policy and management decisions towards sustainable poplar plantations. PMID:26531329

  9. Co-liquefaction of the Elbistan Lignite and Poplar Sawdust. Part I: The Effect of the Liquefaction Parameters

    SciTech Connect

    Karaca, H.; Acar, M.; Yilmaz, M.; Keklik, I.

    2009-07-01

    In this study, the liquefaction of Elbistan lignite and poplar sawdust, and the co-liquefaction of the Elbistan lignite and the poplar sawdust in an inert atmosphere and in non-catalytic conditions have been examined. Also, the effects of solvent/coal ratio and stirring speed on the total conversion derived as the result of the liquefaction process was attempted to be determined. Based on the results, although the effects of the solvent/coal ratio and the stirring speed on total conversion are similar for both the Elbistan lignite and the poplar sawdust, it was also noted that, under similar conditions, the conversion for the poplar sawdust was higher, as compared to the conversion of the Elbistan lignite. As the result of the liquefaction of Elbistan lignite and poplar sawdust under inert atmospheric conditions, the total conversion was increased partially, depending on both solvent/coal ratio and the speed of stirring. However, it was also noted that the total conversion did not change to a significant extent in high solvent/coal ratios and in stirring speed. As the result of the co-liquefaction of the Elbistan lignite and poplar sawdust under inert atmospheric conditions, total conversion was increased, based on the solvent/coal ratio. However, as in the case of the liquefaction of Elbistan lignite and poplar sawdust, it was noted that the high solvent/coal ratios (i.e., solvent/coal ratios of higher than 2/1) did not have a significant effect on the total conversion that was derived as the result of the co-liquefaction of the Elbistan lignite and poplar sawdust.

  10. Windows of opportunity: white-tailed deer and the dynamics of northern hardwood forests of the northeastern US

    USGS Publications Warehouse

    Sage, R.W.; Porter, W.F.; Underwood, H.B.

    2003-01-01

    Herbivory, lighting regimes, and site conditions are among the most important determinants of forest regeneration success, but these are affected by a host of other factors such as weather, predation, human exploitation, pathogens, wind and fire. We draw together > 50 years of research on the Huntington Wildlife Forest in the central Adirondack Mountains of New York to explore regeneration of northern hardwoods. A series of studies each of which focused on a single factor failed to identify the cause of regeneration failure. However, integration of these studies led to broader understanding of the process of forest stand development and identified at least three interacting factors: lighting regime, competing vegetation and selective browsing by white-tailed deer (Odocoileus virginianus). The diverse 100-200 year-old hardwood stands present today probably reflect regeneration during periods of low deer density (< 2.0 deer/km super(2)) and significant forest disturbance. If this hypothesis is correct, forest managers can mimic these 'natural windows of opportunity' through manipulation of a few sensitive variables in the system. Further, these manipulations can be conducted on a relatively small geographic scale. Control of deer densities on a scale of 500 ha and understory American beech (Fagus grandifolia) on a scale of < 100 ha in conjunction with an even-aged regeneration system consistently resulted in successful establishment of desirable hardwood regeneration.

  11. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots.

    PubMed

    Courty, P E; Labbé, J; Kohler, A; Marçais, B; Bastien, C; Churin, J L; Garbaye, J; Le Tacon, F

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F(1) individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  12. Epigenetic Diversity of Clonal White Poplar (Populus alba L.) Populations: Could Methylation Support the Success of Vegetative Reproduction Strategy?

    PubMed Central

    Guarino, Francesco; Cicatelli, Angela; Brundu, Giuseppe; Heinze, Berthold; Castiglione, Stefano

    2015-01-01

    The widespread poplar populations of Sardinia are vegetatively propagated and live in different natural environments forming large monoclonal stands. The main goals of the present study were: i) to investigate/measure the epigenetic diversity of the poplar populations by determining their DNA methylation status; ii) to assess if and how methylation status influences population clustering; iii) to shed light on the changes that occur in the epigenome of ramets of the same poplar clone. To these purposes, 83 white poplar trees were sampled at different locations on the island of Sardinia. Methylation sensitive amplified polymorphism analysis was carried out on the genomic DNA extracted from leaves at the same juvenile stage. The study showed that the genetic biodiversity of poplars is quite limited but it is counterbalanced by epigenetic inter-population molecular variability. The comparison between MspI and HpaII DNA fragmentation profiles revealed that environmental conditions strongly influence hemi-methylation of the inner cytosine. The variable epigenetic status of Sardinian white poplars revealed a decreased number of population clusters. Landscape genetics analyses clearly demonstrated that ramets of the same clone were differentially methylated in relation to their geographic position. Therefore, our data support the notion that studies on plant biodiversity should no longer be restricted to genetic aspects, especially in the case of vegetatively propagated plant species. PMID:26147352

  13. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots

    PubMed Central

    Courty, P. E.; Labbé, J.; Kohler, A.; Marçais, B.; Bastien, C.; Churin, J. L.; Garbaye, J.; Le Tacon, F.

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F1 individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  14. Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level.

    PubMed

    Zenone, Terenzio; Hendriks, Carlijn; Brilli, Federico; Fransen, Erik; Gioli, Beniamio; Portillo-Estrada, Miguel; Schaap, Martijn; Ceulemans, Reinhart

    2016-01-01

    The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health. PMID:27615148

  15. Feasibility of growing hardwood species on a borrow pit amended with either fertilizer and lime or sewage sludge. Progress report

    SciTech Connect

    Berry, C.R.

    1984-01-01

    Previous research on other sites showed that 15 tons/A of dried sewage sludge followed by subsoiling is sufficient to promote rapid growth of pines and sweetgum on borrow pits. During the past year, data have been obtained from this experiment showing that 30 tons/A of sewage sludge, well incorporated and followed by subsoiling, will promote very rapid first-year growth of green ash, yellow poplar, sycamore, and sawtooth oak. Loblolly pine and sweetgum also grew well as in previous studies. In most cases, seedlings of these species grew significantly faster with sewage sludge than with 1000 lbs./Aof 10-10-10 fertilizer and 2 tons/A of lime. Yellow poplar and sycamore grew the faster of all species, attaining heights during the first growing season of 134 and 209 cms, respectively. Sweetgum, green ash, and sawtooth oak all attained heights over 100 cms.

  16. Biological Monitoring Program for East Fork Poplar Creek

    SciTech Connect

    Adams, S.M.; Christensen, S.W.; Greeley, M.S.jr; Hill, W.R.; Kszos, L.A.; McCarthy, J.F.; Peterson, M.J.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.

    1998-10-15

    In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biologicai Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the compiex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity of EFPC, These tasks are (1) toxicity monitoring, (2) biological indicator studies, (3) bioaccumuiation studies, and (4) ecological surveys of the periphyton, benthic macro invertebrate, and fish communities. Monitoring is currently being conducted at five sites, although sites maybe excluded and/or others added depending upon the specific objectives of the various tasks. Criteria used in selecting the sites include: (1) location of sampling sites used in other studies, (2) known or suspected sources of downstream impacts, (3) proximity to U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR) boundaries, (4) concentration of mercury in the adjacent floodplain, (5) appropriate habitat distribution, and (6

  17. What is disjunctive xylem parenchyma? A case study of the African tropical hardwood Okoubaka aubrevillei (Santalaceae).

    PubMed

    Kitin, Peter; Beeckman, Hans; Fujii, Tomoyuki; Funada, Ryo; Noshiro, Shuichi; Abe, Hisashi

    2009-08-01

    The morphological variation and structure-function relationships of xylem parenchyma still remain open to discussion. We analyzed the three-dimensional structure of a poorly known type of xylem parenchyma with disjunctive walls in the tropical hardwood Okoubaka aubrevillei (Santalaceae). Disjunctive cells occurred among the apotracheal parenchyma cells and at connections between axial and ray parenchyma cells. The disjunctive cells were partly detached one from another, but their tubular structures connected them into a continuous network of axial and ray parenchyma. The connecting tubules had thick secondary walls and simple pits with plasmodesmata at the points where one cell contacted a tubule of another cell. The imperforate tracheary elements of the ground tissue were seven times longer than the axial parenchyma strands, a fact that supports a hypothesis that parenchyma cells develop disjunctive walls because they are pulled apart and partly separated during the intrusive growth of fibers. We discuss unresolved details of the formation of disjunctive cell walls and the possible biomechanical advantage of the wood with disjunctive parenchyma: the proportion of tissue that improves mechanical strength is increased by the intrusive elongation of fibers (thick-walled tracheids), whereas the symplastic continuum of the parenchyma is maintained through formation of disjunctive cells. PMID:21628287

  18. Improvement of butanol production from a hardwood hemicelluloses hydrolysate by combined sugar concentration and phenols removal.

    PubMed

    Mechmech, Fatma; Chadjaa, Hassan; Rahni, Mohamed; Marinova, Mariya; Ben Akacha, Najla; Gargouri, Mohamed

    2015-09-01

    The feasibility of using hardwood hemicellulosic pre-hydrolysate recovered from a dissolving pulping process for Acetone-Butanol-Ethanol (ABE) fermentation has been investigated. Dilutions and detoxification methods based on flocculation and nanofiltration were tested to determine the inhibitory concentration of phenolic compounds and to evaluate the efficiency of inhibitors removal on fermentation. Flocculation carried out with ferric sulfate was the most effective method for removal of phenolics (56%) and acetic acid (80%). The impact on fermentation was significant, with an ABE production of 6.40 g/L and 4.25 g/L when using flocculation or combined nanofiltration/flocculation respectively, as compared to a non-significant production for the untreated hydrolysate. By decreasing the toxicity effect of inhibitors, this study reports for the first time that the use of these techniques is efficient to increase the inhibitory concentration threshold of phenols, from 0.3g/L in untreated hydrolysate, to 1.1g/L in flocculated and in nanofiltrated and flocculated hydrolysates. PMID:26046428

  19. Reliance on shallow soil water in a mixed-hardwood forest in central Pennsylvania

    PubMed Central

    Gaines, Katie P.; Stanley, Jane W.; Meinzer, Frederick C.; McCulloh, Katherine A.; Woodruff, David R.; Chen, Weile; Adams, Thomas S.; Lin, Henry; Eissenstat, David M.

    2016-01-01

    We investigated depth of water uptake of trees on shale-derived soils in order to assess the importance of roots over a meter deep as a driver of water use in a central Pennsylvania catchment. This information is not only needed to improve basic understanding of water use in these forests but also to improve descriptions of root function at depth in hydrologic process models. The study took place at the Susquehanna Shale Hills Critical Zone Observatory in central Pennsylvania. We asked two main questions: (i) Do trees in a mixed-hardwood, humid temperate forest in a central Pennsylvania catchment rely on deep roots for water during dry portions of the growing season? (ii) What is the role of tree genus, size, soil depth and hillslope position on the depth of water extraction by trees? Based on multiple lines of evidence, including stable isotope natural abundance, sap flux and soil moisture depletion patterns with depth, the majority of water uptake during the dry part of the growing season occurred, on average, at less than ∼60 cm soil depth throughout the catchment. While there were some trends in depth of water uptake related to genus, tree size and soil depth, water uptake was more uniformly shallow than we expected. Our results suggest that these types of forests may rely considerably on water sources that are quite shallow, even in the drier parts of the growing season. PMID:26546366

  20. Contrasting effects of hardwood and softwood organosolv lignins on enzymatic hydrolysis of lignocellulose.

    PubMed

    Lai, Chenhuan; Tu, Maobing; Shi, Zhiqiang; Zheng, Ke; Olmos, Luis G; Yu, Shiyuan

    2014-07-01

    Identifying an appropriate parameter to elucidate effects of lignin on enzymatic hydrolysis is essential to understand the interactions between enzymes and lignin. Contrasting effects of hardwood organosolv lignin (EOL-SG) and softwood organosolv lignin (EOL-LP) on enzymatic hydrolysis were observed. The addition of EOL-SG (8 g/L) significantly improved the 72 h hydrolysis yields of organosolv pretreated sweetgum (OPSG) and loblolly pine (OPLP) from 49.3% to 68.6% and from 41.2% to 60.8%, respectively. In contrast, the addition of EOL-LP decreased the 72 h hydrolysis yields of OPSG and OPLP to 42.0% and 38.1%, respectively. A strong correlation between the distribution coefficients of cellulase enzymes on lignins and the changes of hydrolysis yields indicated that the inhibitory or stimulatory effects of organosolv lignins on enzymatic hydrolysis were governed by the distribution coefficients (R). The different R values probably were related to the electrostatic interactions, hydrophobic interactions and hydrogen bondings between enzymes and lignin. PMID:24835744

  1. Preliminary Genomic Characterization of Ten Hardwood Tree Species from Multiplexed Low Coverage Whole Genome Sequencing

    PubMed Central

    Staton, Margaret; Best, Teodora; Khodwekar, Sudhir; Owusu, Sandra; Xu, Tao; Xu, Yi; Jennings, Tara; Cronn, Richard; Arumuganathan, A. Kathiravetpilla; Coggeshall, Mark; Gailing, Oliver; Liang, Haiying; Romero-Severson, Jeanne; Schlarbaum, Scott; Carlson, John E.

    2015-01-01

    Forest health issues are on the rise in the United States, resulting from introduction of alien pests and diseases, coupled with abiotic stresses related to climate change. Increasingly, forest scientists are finding genetic/genomic resources valuable in addressing forest health issues. For a set of ten ecologically and economically important native hardwood tree species representing a broad phylogenetic spectrum, we used low coverage whole genome sequencing from multiplex Illumina paired ends to economically profile their genomic content. For six species, the genome content was further analyzed by flow cytometry in order to determine the nuclear genome size. Sequencing yielded a depth of 0.8X to 7.5X, from which in silico analysis yielded preliminary estimates of gene and repetitive sequence content in the genome for each species. Thousands of genomic SSRs were identified, with a clear predisposition toward dinucleotide repeats and AT-rich repeat motifs. Flanking primers were designed for SSR loci for all ten species, ranging from 891 loci in sugar maple to 18,167 in redbay. In summary, we have demonstrated that useful preliminary genome information including repeat content, gene content and useful SSR markers can be obtained at low cost and time input from a single lane of Illumina multiplex sequence. PMID:26698853

  2. Deconstruction of Nordic hardwood in switchable ionic liquids and acylation of the dissolved cellulose.

    PubMed

    Eta, Valerie; Mikkola, Jyri-Pekka

    2016-01-20

    Nordic hardwood (Betula pendula) was fractionated in a batch autoclave equipped with a custom-made SpinChem(®) rotating bed reactor, at 120 °C using CO2 and CS2-based switchable ionic liquids systems. Analyses of the non-dissolved wood after treatment showed that 64 wt% of hemicelluloses and 70 wt% of lignin were removed from the native wood. Long processing periods or successive short-time treatments using fresh SILs further decreased the amount of hemicelluloses and lignin in the non-dissolved fraction to 12 and 15 wt%, respectively. The cellulose-rich fraction was partially dissolved in an organic superbase and an ionic liquid system for further derivatization. Homogeneous acylation of the dissolved cellulose in the presence or absence of catalyst resulted in cellulose acetates with variable degree of substitution (DS), depending on the treatment conditions. By varying the reaction conditions, the cellulose acetate with the desired DS could be obtained under mild conditions. PMID:26572376

  3. Study of the Neutralization and Stabilization of a Mixed Hardwood Bio-Oil

    SciTech Connect

    Moens, L.; Black, S. K.; Myers, M. D.; Czernik, S.

    2009-01-01

    Fast-pyrolysis bio-oil that is currently produced from lignocellulosic biomass in demonstration and semicommercial plants requires significant modification to become an acceptable transportation fuel. The high acidity and chemical instability of bio-oils render them incompatible with existing petroleum refinery processes that produce gasoline and diesel fuels. To facilitate the use of bio-oil as a feedstock in a traditional refinery infrastructure, there is considerable interest in upgrading bio-oils through chemical pathways that include converting the carboxylic acids and reactive carbonyl compounds into esters and acetals using low-cost alcohols. In this article, we discuss our observations with different approaches to esterification and etherification chemistry using a crude bio-oil derived from mixed hardwoods. The high water content in crude bio-oils (ca. 20?30%) creates equilibrium limitations in the condensation reactions that hamper the upgrading process in that the neutralization and stabilization steps cannot easily be driven to completion. The lowest acid number that we were able to obtain without causing serious degradation of the flow properties of the bio-oil had a total acid number of about 20, a value that is still too high for use in a traditional petroleum refinery.

  4. Changes in hardwood forest understory plant communities in response to European earthworm invasions.

    PubMed

    Hale, Cindy M; Frelich, Lee E; Reich, Peter B

    2006-07-01

    European earthworms are colonizing earthworm-free northern hardwood forests across North America. Leading edges of earthworm invasion provide an opportunity to investigate the response of understory plant communities to earthworm invasion and whether the species composition of the earthworm community influences that response. Four sugar maple-dominated forest sites with active earthworm invasions were identified in the Chippewa National Forest in north central Minnesota, USA. In each site, we established a 30 x 150 m sample grid that spanned a visible leading edge of earthworm invasion and sampled earthworm populations and understory vegetation over four years. Across leading edges of earthworm invasion, increasing total earthworm biomass was associated with decreasing diversity and abundance of herbaceous plants in two of four study sites, and the abundance and density of tree seedlings decreased in three of four study sites. Sample points with the most diverse earthworm species assemblage, independent of biomass, had the lowest plant diversity. Changes in understory plant community composition were most affected by increasing biomass of the earthworm species Lumbricus rubellus. Where L. rubellus was absent there was a diverse community of native herbaceous plants, but where L. rubellus biomass reached its maximum, the herbaceous-plant community was dominated by Carex pensylvanica and Arisaema triphyllum and, in some cases, was completely absent. Evidence from these forest sites suggests that earthworm invasion can lead to dramatic changes in the understory community and that the nature of these changes is influenced by the species composition of the invading earthworm community. PMID:16922315

  5. Changes in forest floor composition and chemistry along an invasive earthworm gradient in a hardwood forest

    NASA Astrophysics Data System (ADS)

    Jourdain, J. N.; Filley, T. R.; Top, S. M.; Thayer, C.; Johnson, A.; Jenkins, M.; Welle, P.; Zurn-Birkhimer, S.; Kroeger, T.; Gemscholars

    2010-12-01

    Recent studies have demonstrated how invasive European earthworm species have caused large and long lasting perturbations to forest floor dynamics and soil composition in many northern hardwood forests. The type of perturbation is driven primarily by the composition and activity of the invasive species and the original state of the forest system. Over the past 4 years we have investigated an invasive earthworm front moving through the Ojibwa Red Lake Reservation (Minnesota). Significant shifts in litter and organic horizon mass were observed, similar to other gradients identified in the region, but the species of earthworms exhibited differences compared to other reservation lands in the region--possibly driven by the availability of recreation fishing near to the sites. Sharp gradients in earthworm abundance were observed exhibiting shifts from 600- 900 individuals per meter square to no observed worms within only 500 meters. The gradients in earthworm activity also influenced decay rates of litter, as was observed by placement of litter decay bags across the gradient. Our findings demonstrate the tenuous nature of many tribal reservation forests and point to the need for policies to address spread on such species to minimize impacts to soil carbon stocks as well as culturally important plant species.

  6. Herbivorous insect response to group selection cutting in a southeastern bottomland hardwood forest.

    SciTech Connect

    Michael D. Ulyshen; James L. Hanula; Scott Horn; Christopher E. Moorman.

    2005-04-01

    ABSTRACT Malaise and pitfall traps were used to sample herbivorous insects in canopy gaps created by group-selection cutting in a bottomland hardwood forest in South Carolina. The traps were placed at the centers, edges, and in the forest adjacent to gaps of different sizes (0.13, 0.26, and 0.50 ha) and ages (1 and 7 yr old) during four sampling periods in 2001. Overall, the abundance and species richness of insect herbivores were greater at the centers of young gaps than at the edge of young gaps or in the forest surrounding young gaps. There were no differences in abundance or species richness among old gap locations (i.e., centers, edges, and forest), and we collected significantly more insects in young gaps than old gaps. The insect communities in old gaps were more similar to the forests surrounding them than young gap communities were to their respective forest locations, but the insect communities in the two forests locations (surrounding young and old gaps) had the highest percent similarity of all. Although both abundance and richness increased in the centers of young gaps with increasing gap size, these differences were not significant.Weattribute the increased numbers of herbivorous insects to the greater abundance of herbaceous plants available in young gaps.

  7. Syringyl Methacrylate, a Hardwood Lignin-Based Monomer for High-Tg Polymeric Materials

    PubMed Central

    2016-01-01

    As viable precursors to a diverse array of macromolecules, biomass-derived compounds must impart wide-ranging and precisely controllable properties to polymers. Herein, we report the synthesis and subsequent reversible addition–fragmentation chain-transfer polymerization of a new monomer, syringyl methacrylate (SM, 2,6-dimethoxyphenyl methacrylate), that can facilitate widespread property manipulations in macromolecules. Homopolymers and heteropolymers synthesized from SM and related monomers have broadly tunable and highly controllable glass transition temperatures ranging from 114 to 205 °C and zero-shear viscosities ranging from ∼0.2 kPa·s to ∼17,000 kPa·s at 220 °C, with consistent thermal stabilities. The tailorability of these properties is facilitated by the controlled polymerization kinetics of SM and the fact that one vs two o-methoxy groups negligibly affect monomer reactivity. Moreover, syringol, the precursor to SM, is an abundant component of depolymerized hardwood (e.g., oak) and graminaceous (e.g., switchgrass) lignins, making SM a potentially sustainable and low-cost candidate for tailoring macromolecular properties. PMID:27213117

  8. Bottomland hardwood reforestation for neotropical migratory birds: are we missing the forest for the trees?

    USGS Publications Warehouse

    Twedt, D.J.; Portwood, J.

    1997-01-01

    Reforestation of bottomland hardwoods on lands managed for wildlife or timber production has historically emphasized planting heavy-seeded oaks (Quercus spp.). Although techniques have been developed for successful oak establishment, these plantings often require 5 or more years before establishing a 3-dimensional forest structure. We suggest that lands planted to fast-growing early-successional species, in combination with oaks, provide: (1) more expedient benefits to Neotropical migratory birds; (2) greater forest diversity; (3) more rapid economic return to landowners; and (4) enhanced public relations. Under good growing conditions, and with effective weed control, some fast-growing species can develop a substantial 3-dimensional forest structure in as few as 2 or 3 years. Forest-breeding Neotropical migratory birds use stands planted with early successional species several years before sites planted solely with oaks. Where desirable, succession to forests with a high proportion of oak species can be achieved on sites initially planted with fast-growing species through silvicultural management.

  9. Reliance on shallow soil water in a mixed-hardwood forest in central Pennsylvania.

    PubMed

    Gaines, Katie P; Stanley, Jane W; Meinzer, Frederick C; McCulloh, Katherine A; Woodruff, David R; Chen, Weile; Adams, Thomas S; Lin, Henry; Eissenstat, David M

    2016-04-01

    We investigated depth of water uptake of trees on shale-derived soils in order to assess the importance of roots over a meter deep as a driver of water use in a central Pennsylvania catchment. This information is not only needed to improve basic understanding of water use in these forests but also to improve descriptions of root function at depth in hydrologic process models. The study took place at the Susquehanna Shale Hills Critical Zone Observatory in central Pennsylvania. We asked two main questions: (i) Do trees in a mixed-hardwood, humid temperate forest in a central Pennsylvania catchment rely on deep roots for water during dry portions of the growing season? (ii) What is the role of tree genus, size, soil depth and hillslope position on the depth of water extraction by trees? Based on multiple lines of evidence, including stable isotope natural abundance, sap flux and soil moisture depletion patterns with depth, the majority of water uptake during the dry part of the growing season occurred, on average, at less than ∼60 cm soil depth throughout the catchment. While there were some trends in depth of water uptake related to genus, tree size and soil depth, water uptake was more uniformly shallow than we expected. Our results suggest that these types of forests may rely considerably on water sources that are quite shallow, even in the drier parts of the growing season. PMID:26546366

  10. Decomposition and carbon storage of hardwood and softwood branches in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; Barlaz, Morton A

    2016-07-01

    Tree branches are an important component of yard waste disposed in U.S. municipal solid waste (MSW) landfills. The objective of this study was to characterize the anaerobic biodegradability of hardwood (HW) and softwood (SW) branches under simulated but optimized landfill conditions by measuring methane (CH4) yields, decay rates, the decomposition of cellulose, hemicellulose and organic carbon, as well as carbon storage factors (CSFs). Carbon conversions to CH4 and CO2 ranged from zero to 9.5% for SWs and 17.1 to 28.5% for HWs. When lipophilic or hydrophilic compounds present in some of the HW and SW samples were extracted, some samples showed increased biochemical methane potentials (BMPs). The average CH4 yield, carbon conversion, and CSF measured here, 59.4mLCH4g(-1) dry material, 13.9%, and 0.39gcarbonstoredg(-1) dry material, respectively, represent reasonable values for use in greenhouse gas inventories in the absence of detailed wood type/species data for landfilled yard waste. PMID:27016683

  11. Sorption of chlorophenols from aqueous solution by granular activated carbon, filter coal, pine and hardwood.

    PubMed

    Hossain, G S M; McLaughlan, R G

    2012-09-01

    Wood and coal, as low-cost sorbents, have been evaluated as an alternative to commercial granular activated carbon (GAC) for chlorophenol removal. Kinetic experiments indicated that filter coal had a significantly lower rate of uptake (approximately 10% of final uptake was achieved after three hours) than the other sorbents, owing to intra-particle diffusion limitations. The data fitted a pseudo-second-order model. Sorption capacity data showed that GAC had a high sorption capacity (294-467 mg g(-1)) compared with other sorbents (3.2-7.5 mg(g-1)). However, wood and coal had a greater sorption capacity per unit surface area than GAC. Sorption equilibrium data was best predicted using a Freundlich adsorption model. The sorption capacity for all sorbents was 2-chlorophenol < 4-chlorophenol < 2, 4-dichlorophenol, which correlates well with solute hydrophobicity, although the relative differences were much less for coal than the other sorbents. The results showed that pine, hardwood and filter coal can be used as sorbent materials for the removal of chlorophenol from water; however, kinetic considerations may limit the application of filter coal. PMID:23240177

  12. Prioritizing bird conservation actions in the Prairie Hardwood transition of the Midwestern United States

    USGS Publications Warehouse

    Thogmartin, Wayne E.; Crimmins, Shawn M.; Pearce, Jennie

    2014-01-01

    Large-scale planning for the conservation of species is often hindered by a poor understanding of factors limiting populations. In regions with declining wildlife populations, it is critical that objective metrics of conservation success are developed to ensure that conservation actions achieve desired results. Using spatially explicit estimates of bird abundance, we evaluated several management alternatives for conserving bird populations in the Prairie Hardwood Transition of the United States. We designed landscapes conserving species at 50% of their current predicted abundance as well as landscapes attempting to achieve species population targets (which often required the doubling of current abundance). Conserving species at reduced (half of current) abundance led to few conservation conflicts. However, because of extensive modification of the landscape to suit human use, strategies for achieving regional population targets for forest bird species would be difficult under even ideal circumstances, and even more so if maintenance of grassland bird populations is also desired. Our results indicated that large-scale restoration of agricultural lands to native grassland and forest habitats may be the most productive conservation action for increasing bird population sizes but the level of landscape transition required to approach target bird population sizes may be societally unacceptable.

  13. Growth of Chaetomium cellulolyticum on Alkali-Pretreated Hardwood Sawdust Solids and Pretreatment Liquor

    PubMed Central

    Pamment, N.; Moo-Young, M.; Hsieh, F.-H.; Robinson, C. W.

    1978-01-01

    The treatment of a hardwood sawdust with 1% NaOH solution at 121°C dissolved 19.7% of the dry matter, mainly hemicellulose and lignin. Fermentation of the treated solids by Chaetomium cellulolyticum for 48 h gave a product containing 12.5% crude protein (total N × 6.25) on a dry weight basis. The in vitro rumen digestibility of the 48-h fermentation product was 30%, compared to 24% for the alkali-treated but unfermented sawdust. Growth was independent of sawdust particle size in the range 40 to 100 mesh. Fermentation of the pretreatment liquor gave a product containing up to 50% crude protein (dry weight basis) with an in vitro rumen digestibility of 65 to 76%. Approximately 6.7 g of crude protein was obtained from the treated solids and 2.2 g from the pretreatment liquor per 100 g of sawdust treated. The product from the pretreatment liquor fermentation has potential as a high-protein animal feed supplement but could not be produced economically without an outlet for the relatively indigestible product from the solids fermentation. Growth on the pretreatment liquor was strongly pH dependent; there was a considerable increase in the lag phase when the pH was lowered from 7.5 to 5.2. This effect appears to be due to an inhibitor whose toxicity is reduced at high pH. PMID:16345308

  14. Development of hardwood seed zones for Tennessee using a geographic information system

    USGS Publications Warehouse

    Post, L.S.; Schlarbaum, S.E.; Van Manen, F.; Cecich, R.A.; Saxton, A.M.; Schneider, J.F.

    2003-01-01

    For species that have no or limited information on genetic variation and adaptability to nonnative sites, there is a need for seed collection guidelines based on biological, climatological, and/or geographical criteria. Twenty-eight hardwood species are currently grown for reforestation purposes at the East Tennessee State Nursery. The majority of these species have had no genetic testing to define guidelines for seed collection location and can be distributed to sites that have a very different environment than that of seed origin(s). Poor survival and/or growth may result if seedlings are not adapted to environmental conditions at the planting location. To address this problem, 30 yr of Tennessee county precipitation and minimum temperature data were analyzed and grouped using a centroid hierarchical cluster analysis. The weather data and elevational data were entered into a Geographic Information System (GIS) and separately layered over Bailey's Ecoregions to develop a seed zone system for Tennessee. The seed zones can be used as a practical guideline for collecting seeds to ensure that the resulting seedlings will be adapted to planting environments.

  15. Abaxial Greening Phenotype in Hybrid Aspen

    PubMed Central

    Nowak, Julia S.; Douglas, Carl J.; Cronk, Quentin C.B.

    2013-01-01

    The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial) and bottom (abaxial) surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively). Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the “abaxial greening” phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1) as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all) putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa) and hybrid aspen (P. tremula x tremuloides), representative of each leaf type (bifacial and isobilateral, respectively). Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS) ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening. PMID:27137376

  16. Effects of cutting orientation in poplar wood biomass size reduction on enzymatic hydrolysis sugar yield.

    PubMed

    Zhang, Meng; Ju, Xiaohui; Song, Xiaoxu; Zhang, Xiao; Pei, Z J; Wang, Donghai

    2015-10-01

    The aim of this study was to understand how cutting orientation in poplar wood biomass size reduction affects enzymatic hydrolysis sugar yield of wood particles. A metal cutting (milling) machine was used to produce poplar wood particles from three cutting orientations. Results showed that cutting orientation significantly affected enzymatic hydrolysis sugar yield of wood particles. In this study, size reduction from the optimum cutting orientation produced 50% more sugars than the other two cutting orientations. Particles from the cutting orientation with the highest sugar yield had a large enzyme accessible area (125 mg orange dye/g biomass, as evaluated by Simons' stain procedure) and low crystallinity (50% crystallinity index, as calculated by the Segal method). Furthermore, small particle size did not necessarily lead to improvement in enzymatic digestibility. PMID:26220047

  17. Short Rotation Woody Crops Program. Quarterly progress report, March 1-May 31, 1985. [Sycamore, alders, black locust, larch, poplars, saltbush

    SciTech Connect

    Wright, L.L.; Perlack, R.D.; Wenzel, C.R.; Trimble, J.L.; Ranney, J.W.

    1985-08-01

    This report covers the progress of the Short Rotation Woody Crops Program (SRWCP) during the third quarter of fiscal year 1985. This report summarizes ORNL management activities, technical activities at ORNL and subcontract institutions, and the technology transfer that is occurring as a result of subcontractor and ORNL activities. Third-year results of a nutrient utilization study confirmed that there were no benefits to quarterly fertilization with urea nitrogen. Testing of one prototype short-rotation intensive culture harvester was conducted on a sycamore plantation on Scott Paper Company land in southern Alabama. Coppice yields of European black alder reported by Iowa State University indicate potential productivity of about 7.2 dry Mg . ha/sup -1/ . year/sup -1/ if the best trees are selected. Coppice yields were more than double first-rotation yields. About 31,000 black locust and larch trees were established in 12 genetic tests at 4 sites in Michigan. Seedling rotation productivity rates of 4-year-old hybrid poplar, based on harvest data, were reported by Pennsylvania State University. Rates varied from 4.8 dry Mg . ha/sup -1/ . year/sup -1/ to 10.7 dry Mg . ha/sup -1/ . year/sup -1/, depending on site, management strategy, and planting year. An efficient method for in vitro micropropagation of elite genotypes of fourwing saltbush was developed by Plant Resources Institute. A new study to evaluate yield/density relationships was established by the USDA Forest Service, Pacific Northwest Forest and Range Experiment Station. Dissertation research on the crown geometry of plantation-grown American sycamore was completed.

  18. Tree water use and rainfall partitioning in a mature poplar-pasture system.

    PubMed

    Guevara-Escobar, A.; Edwards, W. R. N.; Morton, R. H.; Kemp, P. D.; Mackay, A. D.

    2000-01-01

    Traditionally, poplars (Populus) have been planted to control erosion on New Zealand's hill-slopes, because of their capacity to dry out and bind together the soil, by reducing effective rainfall and increasing evapotranspiration and soil strength. However, the effect of widely spaced poplars on the partitioning of soil water and rainfall has not been reported. This study determined rainfall partitioning for 18 mid-spring days in a mature P. deltoides (Bart. ex Marsh, Clone I78)-pasture association (37 stems per hectare, unevenly spaced at 16.4 +/- 0.4 m) and compared it with a traditional open pasture system in grazed areas of a hill environment. Tree transpiration was measured by the heat pulse technique. A time-driven mathematical model was used to set a zero offset, adjust anomalous values and describe simultaneous sap velocity time courses of trees. The model showed that daylight sap flow velocities can be represented with a nonlinear Beta function (R(2) > 0.98), and differences in the parameters representing the initiation, duration and conformation of the sap velocity can be tested statistically to discern tree transpiration differences during the day. Evapotranspiration was greater for the poplar-pasture association than for the open pasture (2.7-3.0 versus 2.2 mm day(-1)). The tree canopy alone contributed 0.92 mm day(-1) as transpiration and 1.37 mm day(-1) as interception, whereas evapotranspiration of the pasture understory was only 0.4-0.6 mm day(-1). Despite the higher water use of the poplar-pasture association, soil water in the 0-300 mm soil stratum was higher than, or similar to, that of the open pasture. Tree shading decreased evapotranspiration and pasture accumulation under the trees. PMID:12651477

  19. RNA-SEQ Reveals Transcriptional Level Changes of Poplar Roots in Different Forms of Nitrogen Treatments

    PubMed Central

    Qu, Chun-Pu; Xu, Zhi-Ru; Hu, Yan-Bo; Lu, Yao; Yang, Cheng-Jun; Sun, Guang-Yu; Liu, Guan-Jun

    2016-01-01

    Poplar has emerged as a model plant for better understanding cellular and molecular changes accompanying tree growth, development, and response to environment. Long-term application of different forms of nitrogen (such as NO3--N and NH4+-N) may cause morphological changes of poplar roots; however, the molecular level changes are still not well-known. In this study, we analyzed the expression profiling of poplar roots treated by three forms of nitrogen: S1 (NH4+), S2 (NH4NO3), and S3 (NO3-) by using RNA-SEQ technique. We found 463 genes significantly differentially expressed in roots by different N treatments, of which a total of 112 genes were found to differentially express between S1 and S2, 171 genes between S2 and S3, and 319 genes between S1 and S3. A cluster analysis shows significant difference in many transcription factor families and functional genes family under different N forms. Through an analysis of Mapman metabolic pathway, we found that the significantly differentially expressed genes are associated with fermentation, glycolysis, and tricarboxylic acid cycle (TCA), secondary metabolism, hormone metabolism, and transport processing. Interestingly, we did not find significantly differentially expressed genes in N metabolism pathway, mitochondrial electron transport/ATP synthesis and mineral nutrition. We also found abundant candidate genes (20 transcription factors and 30 functional genes) regulating morphology changes of poplar roots under the three N forms. The results obtained are beneficial to a better understanding of the potential molecular and cellular mechanisms regulating root morphology changes under different N treatments. PMID:26870068

  20. Structural evaluation and bioethanol production by simultaneous saccharification and fermentation with biodegraded triploid poplar

    PubMed Central

    2013-01-01

    Background Pretreatment is a key step to decrease the recalcitrance of lignocelluloses and then increase the digestibility of cellulose in second-generation bioethanol production. In this study, wood chips from triploid poplar were biopretreated with white rot fungus Trametes velutina D10149. The effects of incubation duration on delignification efficiency and structural modification of cellulose were comparably studied, as well as the digestibility of cellulose by simultaneous saccharification and fermentation (SSF). Results Although microbial pretreatments did not significantly introduce lignin degradation, the data from SSF exhibited higher cellulose conversion (21-75% for biopretreated samples for 4–16 weeks) as compared to the untreated poplar (18%). In spite of the essential maintain of crystallinity, the modification of lignin structure during fungal treatment undoubtedly played a key role in improving cellulose bioconversion rates. Finally, the ethanol concentration of 5.16 g/L was detected in the fermentation broth from the cellulosic sample biodegraded for 16 weeks after 24 h SSF, achieving 34.8% cellulose utilization in poplar. Conclusion The potential fungal pretreatment with Trametes velutina D10149 was firstly explored in this study. It is found that the biopretreatment process had a significant effect on the digestibility of substrate probably due to the removal and unit variation of lignin, since the crystallinities of substrates were rarely changed. Additional investigation is still required especially to improve the selectivity for lignin degradation and optimize the digestibility of cellulose. PMID:23517540

  1. Host Genotype Shapes the Foliar Fungal Microbiome of Balsam Poplar (Populus balsamifera)

    PubMed Central

    Bálint, Miklós; Tiffin, Peter; Hallström, Björn; O’Hara, Robert B.; Olson, Matthew S.; Fankhauser, Johnathon D.; Piepenbring, Meike; Schmitt, Imke

    2013-01-01

    Foliar fungal communities of plants are diverse and ubiquitous. In grasses endophytes may increase host fitness; in trees, their ecological roles are poorly understood. We investigated whether the genotype of the host tree influences community structure of foliar fungi. We sampled leaves from genotyped balsam poplars from across the species' range, and applied 454 amplicon sequencing to characterize foliar fungal communities. At the time of the sampling the poplars had been growing in a common garden for two years. We found diverse fungal communities associated with the poplar leaves. Linear discriminant analysis and generalized linear models showed that host genotypes had a structuring effect on the composition of foliar fungal communities. The observed patterns may be explained by a filtering mechanism which allows the trees to selectively recruit fungal strains from the environment. Alternatively, host genotype-specific fungal communities may be present in the tree systemically, and persist in the host even after two clonal reproductions. Both scenarios are consistent with host tree adaptation to specific foliar fungal communities and suggest that there is a functional basis for the strong biotic interaction. PMID:23326555

  2. Water stress induces changes in polyphenol profile and antioxidant capacity in poplar plants (Populus spp.).

    PubMed

    Popović, B M; Štajner, D; Ždero-Pavlović, R; Tumbas-Šaponjac, V; Čanadanović-Brunet, J; Orlović, S

    2016-08-01

    This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO. PMID:27116372

  3. Investigating Mass Transport Limitations on Xylan Hydrolysis During Dilute Acid Pretreatment of Poplar

    SciTech Connect

    Mittal, Ashutosh; Pilath, Heid M.; Parent, Yves; Chatterjee, Siddharth G.; Donohoe, Bryon S.; Yarbrough, John M.; Himmel, Michael E.; Nimlos, Mark R.; Johnson, David K.

    2014-04-28

    Mass transport limitations could be an impediment to achieving high sugar yields during biomass pretreatment and thus be a critical factor in the economics of biofuels production. The objective of this work was to study the mass transfer restrictions imposed by the structure of biomass on the hydrolysis of xylan during dilute acid pretreatment of biomass. Mass transfer effects were studied by pretreating poplar wood at particle sizes ranging from 10 micrometers to 10 mm. This work showed a significant reduction in the rate of xylan hydrolysis in poplar when compared to the intrinsic rate of hydrolysis for isolated xylan that is possible in the absence of mass transfer. In poplar samples we observed no significant difference in the rates of xylan hydrolysis over more than two orders of magnitude in particle size. It appears that no additional mass transport restrictions are introduced by increasing particle size from 10 micrometers to 10 mm. This work suggests that the rates of xylan hydrolysis in biomass particles are limited primarily by the diffusion of hydrolysis products out of plant cell walls. A mathematical description is presented to describe the kinetics of xylan hydrolysis that includes transport of the hydrolysis products through biomass into the bulk solution. The modeling results show that the effective diffusion coefficient of the hydrolysis products in the cell wall is several orders of magnitude smaller than typical values in other applications signifying the role of plant cell walls in offering resistance to diffusion of the hydrolysis products.

  4. Red Xylem and Higher Lignin Extractability by Down-Regulating a Cinnamyl Alcohol Dehydrogenase in Poplar.

    PubMed Central

    Baucher, M.; Chabbert, B.; Pilate, G.; Van Doorsselaere, J.; Tollier, M. T.; Petit-Conil, M.; Cornu, D.; Monties, B.; Van Montagu, M.; Inze, D.; Jouanin, L.; Boerjan, W.

    1996-01-01

    Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. We have down-regulated CAD in transgenic poplar (Populus tremula X Populus alba) by both antisense and co-suppression strategies. Several antisense and sense CAD transgenic poplars had an approximately 70% reduced CAD activity that was associated with a red coloration of the xylem tissue. Neither the lignin amount nor the lignin monomeric composition (syringyl/guaiacyl) were significantly modified. However, phloroglucinol-HCl staining was different in the down-regulated CAD plants, suggesting changes in the number of aldehyde units in the lignin. Furthermore, the reactivity of the cell wall toward alkali treatment was altered: a lower amount of lignin was found in the insoluble, saponified residue and more lignin could be precipitated from the soluble alkali fraction. Moreover, large amounts of phenolic compounds, vanillin and especially syringaldehyde, were detected in the soluble alkali fraction of the CAD down-regulated poplars. Alkaline pulping experiments on 3-month-old trees showed a reduction of the kappa number without affecting the degree of cellulose degradation. These results indicate that reducing the CAD activity in trees might be a valuable strategy to optimize certain processes of the wood industry, especially those of the pulp and paper industry. PMID:12226459

  5. Overexpression of poplar cellulase accelerates growth and disturbs the closing movements of leaves in sengon.

    PubMed

    Hartati, Sri; Sudarmonowati, Enny; Park, Yong Woo; Kaku, Tomomi; Kaida, Rumi; Baba, Kei'ichi; Hayashi, Takahisa

    2008-06-01

    In this study, poplar (Populus alba) cellulase (PaPopCel1) was overexpressed in a tropical Leguminosae tree, sengon (Paraserianthes falcataria), by the Agrobacterium tumefaciens method. PaPopCel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. The pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. When main veins from each genotype were excised and placed on a paper towel, however, the leaves of the transgenic plants closed more rapidly than those of the wild-type plant. Based on carbohydrate analyses of cell walls, the leaves of the transgenic plants contained less wall-bound xyloglucan than those of the wild-type plants. In situ xyloglucan endotransglucosylase activity showed that the incorporation of whole xyloglucan, potentially for wall tightening, occurred in the parenchyma cells (motor cells) of the petiolule pulvinus attached to the main vein, although the transgenic plant incorporated less whole xyloglucan than the wild-type plant. These observations support the hypothesis that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase, which loosens xyloglucan intercalation, resulting in an irreversible wall modification. This process could be the reason why the overexpression of poplar cellulase both promotes plant growth and disturbs the biological clock of the plant by altering the closing movements of the leaves of the plant. PMID:18417637

  6. Effector-Mining in the Poplar Rust Fungus Melampsora larici-populina Secretome

    PubMed Central

    Lorrain, Cécile; Hecker, Arnaud; Duplessis, Sébastien

    2015-01-01

    The poplar leaf rust fungus, Melampsora larici-populina has been established as a tree-microbe interaction model. Understanding the molecular mechanisms controlling infection by pathogens appears essential for durable management of tree plantations. In biotrophic plant-parasites, effectors are known to condition host cell colonization. Thus, investigation of candidate secreted effector proteins (CSEPs) is a major goal in the poplar–poplar rust interaction. Unlike oomycetes, fungal effectors do not share conserved motifs and candidate prediction relies on a set of a priori criteria established from reported bona fide effectors. Secretome prediction, genome-wide analysis of gene families and transcriptomics of M. larici-populina have led to catalogs of more than a thousand secreted proteins. Automatized effector-mining pipelines hold great promise for rapid and systematic identification and prioritization of CSEPs for functional characterization. In this review, we report on and discuss the current status of the poplar rust fungus secretome and prediction of candidate effectors from this species. PMID:26697026

  7. UV-B mediated metabolic rearrangements in poplar revealed by non-targeted metabolomics.

    PubMed

    Kaling, Moritz; Kanawati, Basem; Ghirardo, Andrea; Albert, Andreas; Winkler, Jana Barbro; Heller, Werner; Barta, Csengele; Loreto, Francesco; Schmitt-Kopplin, Philippe; Schnitzler, Jörg-Peter

    2015-05-01

    Plants have to cope with various abiotic stresses including UV-B radiation (280-315 nm). UV-B radiation is perceived by a photoreceptor, triggers morphological responses and primes plant defence mechanisms such as antioxidant levels, photoreapir or accumulation of UV-B screening pigments. As poplar is an important model system for trees, we elucidated the influence of UV-B on overall metabolite patterns in poplar leaves grown under high UV-B radiation. Combining non-targeted metabolomics with gas exchange analysis and confocal microscopy, we aimed understanding how UV-B radiation triggers metabolome-wide changes, affects isoprene emission, photosynthetic performance, epidermal light attenuation and finally how isoprene-free poplars adjust their metabolome under UV-B radiation. Exposure to UV-B radiation caused a comprehensive rearrangement of the leaf metabolome. Several hundreds of metabolites were up- and down-regulated over various pathways. Our analysis, revealed the up-regulation of flavonoids, anthocyanins and polyphenols and the down-regulation of phenolic precursors in the first 36 h of UV-B treatment. We also observed a down-regulation of steroids after 12 h. The accumulation of phenolic compounds leads to a reduced light transmission in UV-B-exposed plants. However, the accumulation of phenolic compounds was reduced in non-isoprene-emitting plants suggesting a metabolic- or signalling-based interaction between isoprenoid and phenolic pathways. PMID:24738572

  8. Poplar Wood Rays Are Involved in Seasonal Remodeling of Tree Physiology1[C][W

    PubMed Central

    Larisch, Christina; Dittrich, Marcus; Wildhagen, Henning; Lautner, Silke; Fromm, Jörg; Polle, Andrea; Hedrich, Rainer; Rennenberg, Heinz; Müller, Tobias; Ache, Peter

    2012-01-01

    Understanding seasonality and longevity is a major challenge in tree biology. In woody species, growth phases and dormancy follow one another consecutively. In the oldest living individuals, the annual cycle may run for more than 1,000 years. So far, however, not much is known about the processes triggering reactivation from dormancy. In this study, we focused on wood rays, which are known to play an important role in tree development. The transition phase from dormancy to flowering in early spring was compared with the phase of active growth in summer. Rays from wood samples of poplar (Populus × canescens) were enriched by laser microdissection, and transcripts were monitored by poplar whole-genome microarrays. The resulting seasonally varying complex expression and metabolite patterns were subjected to pathway analyses. In February, the metabolic pathways related to flower induction were high, indicating that reactivation from dormancy was already taking place at this time of the year. In July, the pathways related to active growth, like lignin biosynthesis, nitrogen assimilation, and defense, were enriched. Based on “marker” genes identified in our pathway analyses, we were able to validate periodical changes in wood samples by quantitative polymerase chain reaction. These studies, and the resulting ray database, provide new insights into the steps underlying the seasonality of poplar trees. PMID:22992511

  9. Ectomycorrhizal colonization and diversity in relation to tree biomass and nutrition in a plantation of transgenic poplars with modified lignin biosynthesis.

    PubMed

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R(2) = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  10. Ectomycorrhizal Colonization and Diversity in Relation to Tree Biomass and Nutrition in a Plantation of Transgenic Poplars with Modified Lignin Biosynthesis

    PubMed Central

    Danielsen, Lara; Lohaus, Gertrud; Sirrenberg, Anke; Karlovsky, Petr; Bastien, Catherine; Pilate, Gilles; Polle, Andrea

    2013-01-01

    Wood from biomass plantations with fast growing tree species such as poplars can be used as an alternative feedstock for production of biofuels. To facilitate utilization of lignocellulose for saccharification, transgenic poplars with modified or reduced lignin contents may be useful. However, the potential impact of poplars modified in the lignification pathway on ectomycorrhizal (EM) fungi, which play important roles for plant nutrition, is not known. The goal of this study was to investigate EM colonization and community composition in relation to biomass and nutrient status in wildtype (WT, Populus tremula × Populus alba) and transgenic poplar lines with suppressed activities of cinnamyl alcohol dehydrogenase, caffeate/5-hydroxyferulate O-methyltransferase, and cinnamoyl-CoA reductase in a biomass plantation. In different one-year-old poplar lines EM colonization varied from 58% to 86%, but the EM community composition of WT and transgenic poplars were indistinguishable. After two years, the colonization rate of all lines was increased to about 100%, but separation of EM communities between distinct transgenic poplar genotypes was observed. The differentiation of the EM assemblages was similar to that found between different genotypes of commercial clones of Populus × euramericana. The transgenic poplars exhibited significant growth and nutrient element differences in wood, with generally higher nutrient accumulation in stems of genotypes with lower than in those with higher biomass. A general linear mixed model simulated biomass of one-year-old poplar stems with high accuracy (adjusted R2 = 97%) by two factors: EM colonization and inverse wood N concentration. These results imply a link between N allocation and EM colonization, which may be crucial for wood production in the establishment phase of poplar biomass plantations. Our data further support that multiple poplar genotypes regardless whether generated by transgenic approaches or conventional

  11. Development of understory vegetation in pine and pine-hardwood shelterwood stands in the Ouachita mountains: The first 3 years. Forest Service research paper

    SciTech Connect

    Shelton, M.G.

    1997-09-01

    The shelterwood reproduction cutting method using two overstory compositions (a pine basal area of 30 square feet per acre with and without 15 square feet per acre of hardwoods) and two methods of submerchantable hardwood control (chain-saw felling with and without stump-applied herbicide) was tested in a 2x2 factorial, split-plot design with four randomized complete blocks. Total coverage of understory vegetation after 3 years was greater in the pine overstory treatment (68 percent) than in the pine-hardwood overstory treatment (46 percent) and was slightly greater for manual than chemical hardwood control (60 versus 55 percent). Results indicate that 15 square feet per acre of scattered hardwoods can be retained through at least 3 years after harvest, but additional monitoring will be needed to determine the long-term success of reproduction. Early results suggest that the herbicide treatment was not justified in the stand and site conditions tested in this study; contributing factors were the abundant pine seed production and low levels of competing vegetation.

  12. Developing a topographic model to predict the northern hardwood forest type within Carolina northern flying squirrel (Glaucomys sabrinus coloratus) recovery areas of the southern Appalachians

    USGS Publications Warehouse

    Evans, Andrew; Odom, Richard H.; Resler, Lynn M.; Ford, W. Mark; Prisley, Stephen

    2014-01-01

    The northern hardwood forest type is an important habitat component for the endangered Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus) for den sites and corridor habitats between boreo-montane conifer patches foraging areas. Our study related terrain data to presence of northern hardwood forest type in the recovery areas of CNFS in the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. We recorded overstory species composition and terrain variables at 338 points, to construct a robust, spatially predictive model. Terrain variables analyzed included elevation, aspect, slope gradient, site curvature, and topographic exposure. We used an information-theoretic approach to assess seven models based on associations noted in existing literature as well as an inclusive global model. Our results indicate that, on a regional scale, elevation, aspect, and topographic exposure index (TEI) are significant predictors of the presence of the northern hardwood forest type in the southern Appalachians. Our elevation + TEI model was the best approximating model (the lowest AICc score) for predicting northern hardwood forest type correctly classifying approximately 78% of our sample points. We then used these data to create region-wide predictive maps of the distribution of the northern hardwood forest type within CNFS recovery areas.

  13. GHGs balance in a land use change process from grassland to short rotation coppice of poplar

    NASA Astrophysics Data System (ADS)

    Sabbatini, Simone; Arriga, Nicola; Baiocco, Andrea; Boschi, Alessio; Castaldi, Simona; Consalvo, Claudia; Gioli, Beniamino; Matteucci, Giorgio; Tomassucci, Michele; Zaldei, Alessandro; Papale, Dario

    2013-04-01

    At present one of the fastest spreading renewable energy sources are bioenergy cultivations. Millions of hectares of traditional crops all over the Europe are expected to be converted in energy crops in the near future, in order to produce green energy and contrast global warming. Last year, in the context of the GHG-Europe FP7 project we set up an experiment to verify the effects on the green-house gases balance of a land use change from traditional agriculture to short rotation coppice of poplar clones in central Italy. CO2 fluxes measured during the last growing season through three Eddy Covariance masts - two on poplar plantations of different ages and one over a reference site (grassland) - have been analysed. We also monitored CO2, CH4 and N2O fluxes from soil measured using chambers in order to better understand the contribution of other GHGs. The two poplar plantations showed a similar uptake of Carbon, 368 g C m-2 year-1 and 358 g C m-2 year-1, while the grassland absorbed 220 g C m-2 year-1 during the same period. Soil respiration in average was higher for the youngest plantation of poplar and for the grassland, lower for the oldest one, where soil is undisturbed from more time. In all the sites we measured low emissions during the winter (between 80 and 150 mg CO2 m-2 h-1), progressively higher in the spring and early summer with growing temperatures (up to 650 mg CO2 m-2 h-1), quite low during the summer because of a strong drought, while the highest values were recorded in September (ca. 1100 mg CO2 m-2 h-1 in the grassland and youngest poplar) after important rain events. Fluxes of N2O and CH4 from soil are very low: little absorption of CH4 in the grassland (values between 0 and -18.75 μg m-2 h-1), with peak after fertilization; in the SRC little absorption or emission with no clear seasonal pattern. Insignificant fluxes of N2O in all crops (even in the grassland after fertilization). The carbon fluxes measured are strongly related to the particular

  14. Biocrude oils from the fast pyrolysis of poultry litter and hardwood.

    PubMed

    Agblevor, F A; Beis, S; Kim, S S; Tarrant, R; Mante, N O

    2010-02-01

    The safe and economical disposal of poultry litter is becoming a major problem for the USA poultry industry. Current disposal methods such as land application and feeding to cattle are now under pressure because of pollution of water resources due to leaching, runoffs and concern for mad cow disease contamination of the food chain. Incineration or combustion is potentially applicable to large scale operations, but for small scale growers and EPA non-attainment areas, this is not a suitable option because of the high cost of operation. Thus, there is a need for developing appropriate technologies to dispose poultry litter. Poultry litters from broiler chicken and turkey houses, as well as bedding material were converted into biocrude oil in a fast pyrolysis fluidized bed reactor. The biocrude oil yields were relatively low ranging from 36 wt% to 50 wt% depending on the age and bedding material content of the litter. The bedding material (which was mostly hardwood shavings) biocrude oil yield was 63 wt%. The higher heating value (HHV) of the poultry litter biocrude oils ranged from 26 MJ/kg to 29 MJ/kg while that of the bedding material was 24 MJ/kg. The oils had relatively high nitrogen content ranging from 4 wt% to 8 wt%, very low sulfur (<1 wt%) content and high viscosity. The viscosities of the oils appeared to be a function of both the source of litter and the pyrolysis temperature. The biochar yield ranged from 27 wt% to 40 wt% depending on the source, age and composition of the poultry litter. The biochar ash content ranged from 24 wt% to 54 wt% and was very rich in inorganic components such as potassium and phosphorous. PMID:19880302

  15. Hardwood biochar and manure co-application to a calcareous soil.

    PubMed

    Ippolito, J A; Stromberger, M E; Lentz, R D; Dungan, R S

    2016-01-01

    Biochar may affect the mineralization rate of labile organic C sources such as manures via microbial community shifts, and subsequently affect nutrient release. In order to ascertain the positive or negative priming effect of biochar on manure, dairy manure (2% by wt.) and a hardwood-based, fast pyrolysis biochar were applied (0%, 1%, 2%, and 10% by wt.) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 6 and 12 months to monitor for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Overall results showed that increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic C content and plant-available Fe and Mn, while a synergistic biochar-manure effect increased plant-available Zn. Compared to the other rates, the 10% biochar application lowered concentrations of NO3-N; effects appeared masked at lower biochar rates due to manure application. Over time, soil NO3-N increased likely due to manure N mineralization, yet soil NO3-N in the 10% biochar rate remained lower as compared to other treatments. In the presence of manure, only the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ∼1%. Our previous findings with biochar alone suggested an overall negative priming effect with increasing biochar application rates, yet when co-applied with manure the negative priming effect was eliminated. PMID:26009473

  16. Supplemental planting of early successional tree species during bottomland hardwood afforestation

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.

    2002-01-01

    Reforestation of former bottom land hardwood forests that have been cleared for agriculture (i.e., afforestation) has historically emphasized planting heavy-seeded oaks (Quercus spp.) and pecans (Carya spp.). These species are slow to develop vertical forest structure. However, vertical forest structure is key to colonization of afforested sites by forest birds. Although early-successional tree species often enhance vertical structure, few of these species invade afforested sites that are distant from seed sources. Furthermore, many land mangers are reluctant to establish and maintain stands of fast-growing plantation trees. Therefore, on 40 afforested bottomland sites, we supplemented heavy-seeded seedlings with 8 patches of fast-growing trees: 4 patches of 12 eastern cottonwood (Populus deltoides) stem cuttings and 4 patches of 12 American sycamore (Platanus occidentalis) seedlings. To enhance survival and growth, tree patches were subjected to 4 weed control treatments: (1) physical weed barriers, (2) chemical herbicide, (3) both physical and chemical weed control, or (4) no weed control. Overall, first-year survival of cottonwood and sycamore was 25 percent and 47 percent, respectively. Second-year survival of extant trees was 52 percent for cottonwood and 77 percent for sycamore. Physical weed barriers increased survival of cottonwoods to 30 percent versus 18 percent survival with no weed control. Similarly, sycamore survival was increased from 49 percent without weed control to 64 percent with physical weed barriers. Chemical weed control adversely impacted sycamore and reduced survival to 35 percent. Tree heights did not differ between species or among weed control treatments. Girdling of trees by deer often destroyed saplings. Thus, little increase in vertical structure was detected between growing seasons. Application of fertilizer and protection via tree shelters did not improve survival or vertical development of sycamore or cottonwood.

  17. Spatial and temporal patterns of beetles associated with coarse woody debris in managed bottomland hardwood forests.

    SciTech Connect

    Ulyshen, M., D.; Hanula, J., L.; Horn, S.; Kilgo, J., C.; Moorman, C., E.

    2004-05-13

    For. Ecol. and Mgt. 199:259-272. Malaise traps were used to sample beetles in artificial canopy gaps of different size (0.13 ha, 0.26 ha, and0.50 ha) and age in a South Carolina bottomland hardwood forest. Traps were placed at the center, edge, and in the surrounding forest of each gap. Young gaps (ý 1 year) had large amounts of coarse woody debris compared to the surrounding forest, while older gaps (ý 6 years) had virtually none. The total abundance and diversity of wood-dwelling beetles (Buprestidae, Cerambycidae, Brentidae, Bostrichidae, and Curculionidae (Scolytinae and Platypodinae)) was higher in the center of young gaps than in the center of old gaps. The abundance was higher in the center of young gaps than in the surrounding forest, while the forest surrounding old gaps and the edge of old gaps had a higher abundance and diversity of wood-dwelling beetles than did the center of old gaps. There was no difference in wood-dwelling beetle abundance between gaps of different size, but diversity was lower in 0.13 ha old gaps than in 0.26 ha or 0.50 ha old gaps. We suspect that gap size has more of an effect on woodborer abundance than indicated here because malaise traps sample a limited area. The predaceous beetle family Cleridae showed a very similar trend to that of the woodborers. Coarse woody debris is an important resource for many organisms, and our results lend further support to forest management practices that preserve coarse woody debris created during timber removal.

  18. Bottomland hardwood establishment and avian colonization of reforested sites in the Mississippi Alluvial Valley

    USGS Publications Warehouse

    Wilson, R.R.; Twedt, D.J.

    2005-01-01

    Reforestation of bottomland hardwood sites in the Mississippi Alluvial Valley has markedly increased in recent years, primarily due to financial incentive programs such as the Wetland Reserve Program, Partners for Wildlife Program, and state and private conservation programs. An avian conservation plan for the Mississippi Alluvial Valley proposes returning a substantial area of cropland to forested wetlands. Understanding how birds colonize reforested sites is important to assess the effectiveness of avian conservation. We evaluated establishment of woody species and assessed bird colonization on 89 reforested sites. These reforested sites were primarily planted with heavy-seeded oaks (Quercus spp.) and pecans (Carya illinoensis). Natural invasion of light-seeded species was expected to diversify these forests for wildlife and sustainable timber harvest. Planted tree species averaged 397 + 36 stems/ha-1, whereas naturally invading trees averaged 1675 + 241 stems/ha. However, naturally invading trees were shorter than planted trees and most natural invasion occurred <100 m from an existing forested edge. Even so, planted trees were relatively slow to develop vertical structure, especially when compared with tree species planted and managed for pulpwood production. Slow development of vertical structure resulted in grassland bird species, particularly dickcissel (Spiza americana) and red-winged blackbird (Agelaius phoeniceus), being the dominant avian colonizers for the first 7 years post-planting. High priority bird species (as defined by Partners in Flight), such as prothonotary warbler (Protonotaria citrea) and wood thrush (Hylocichla mustelina), were not frequently detected until stands were 15 years old. Canonical correspondence analysis revealed tree height had the greatest influence on the bird communities colonizing reforested sites. Because colonization by forest birds is dependent on tree height, we recommend inclusion of at least one fast-growing tree

  19. Nitrogen biogeochemistry in the Adirondack Mountains of New York: hardwood ecosystems and associated surface waters.

    PubMed

    Mitchell, Myron J; Driscoll, Charles T; Inamdar, Shreeram; McGee, Greg G; Mbila, Monday O; Raynal, Dudley J

    2003-01-01

    Studies on the nitrogen (N) biogeochemistry in Adirondack northern hardwood ecosystems were summarized. Specific focus was placed on results at the Huntington Forest (HFS), Pancake-Hall Creek (PHC), Woods Lake (WL), Ampersand (AMO), Catlin Lake (CLO) and Hennessy Mountain (HM). Nitrogen deposition generally decreased from west to east in the Adirondacks, and there have been no marked temporal changes in N deposition from 1978 through 1998. Second-growth western sites (WL, PHC) had higher soil solution NO(3-) concentrations and fluxes than the HFS site in the central Adirondacks. Of the two old-growth sites (AMO and CLO), AMO had substantially higher NO(3-) concentrations due to the relative dominance of sugar maple that produced litter with high N mineralization and nitrification rates. The importance of vegetation in affecting N losses was also shown for N-fixing alders in wetlands. The Adirondack Manipulation and Modeling Project (AMMP) included separate experimental N additions of (NH4)2SO4 at WL, PHC and HFS and HNO3 at WL and HFS. Patterns of N loss varied with site and form of N addition and most of the N input was retained. For 16 lake/watersheds no consistent changes in NO(3-) concentrations were found from 1982 to 1997. Simulations suggested that marked NO(3-) loss will only be manifested over extended periods. Studies at the Arbutus Watershed provided information on the role of biogeochemical and hydrological factors in affecting the spatial and temporal patterns of NO(3-) concentrations. The heterogeneous topography in the Adirondacks has generated diverse landscape features and patterns of connectivity that are especially important in regulating the temporal and spatial patterns of NO(3-) concentrations in surface waters. PMID:12667763

  20. Social insects dominate eastern US temperate hardwood forest macroinvertebrate communities in warmer regions.

    PubMed

    King, Joshua R; Warren, Robert J; Bradford, Mark A

    2013-01-01

    Earthworms, termites, and ants are common macroinvertebrates in terrestrial environments, although for most ecosystems data on their abundance and biomass is sparse. Quantifying their areal abundance is a critical first step in understanding their functional importance. We intensively sampled dead wood, litter, and soil in eastern US temperate hardwood forests at four sites, which span much of the latitudinal range of this ecosystem, to estimate the abundance and biomass m(-2) of individuals in macroinvertebrate communities. Macroinvertebrates, other than ants and termites, differed only slightly among sites in total abundance and biomass and they were similar in ordinal composition. Termites and ants were the most abundant macroinvertebrates in dead wood, and ants were the most abundant in litter and soil. Ant abundance and biomass m(-2) in the southernmost site (Florida) were among the highest values recorded for ants in any ecosystem. Ant and termite biomass and abundance varied greatly across the range, from <1% of the total macroinvertebrate abundance (in the northern sites) to >95% in the southern sites. Our data reveal a pronounced shift to eusocial insect dominance with decreasing latitude in a temperate ecosystem. The extraordinarily high social insect relative abundance outside of the tropics lends support to existing data suggesting that ants, along with termites, are globally the most abundant soil macroinvertebrates, and surpass the majority of other terrestrial animal (vertebrate and invertebrate) groups in biomass m(-2). Our results provide a foundation for improving our understanding of the functional role of social insects in regulating ecosystem processes in temperate forest. PMID:24116079

  1. Biocrude oils from the fast pyrolysis of poultry litter and hardwood

    SciTech Connect

    Agblevor, F.A.; Beis, S.; Kim, S.S.; Tarrant, R.; Mante, N.O.

    2010-02-15

    The safe and economical disposal of poultry litter is becoming a major problem for the USA poultry industry. Current disposal methods such as land application and feeding to cattle are now under pressure because of pollution of water resources due to leaching, runoffs and concern for mad cow disease contamination of the food chain. Incineration or combustion is potentially applicable to large scale operations, but for small scale growers and EPA non-attainment areas, this is not a suitable option because of the high cost of operation. Thus, there is a need for developing appropriate technologies to dispose poultry litter. Poultry litters from broiler chicken and turkey houses, as well as bedding material were converted into biocrude oil in a fast pyrolysis fluidized bed reactor. The biocrude oil yields were relatively low ranging from 36 wt% to 50 wt% depending on the age and bedding material content of the litter. The bedding material (which was mostly hardwood shavings) biocrude oil yield was 63 wt%. The higher heating value (HHV) of the poultry litter biocrude oils ranged from 26 MJ/kg to 29 MJ/kg while that of the bedding material was 24 MJ/kg. The oils had relatively high nitrogen content ranging from 4 wt% to 8 wt%, very low sulfur (<1 wt%) content and high viscosity. The viscosities of the oils appeared to be a function of both the source of litter and the pyrolysis temperature. The biochar yield ranged from 27 wt% to 40 wt% depending on the source, age and composition of the poultry litter. The biochar ash content ranged from 24 wt% to 54 wt% and was very rich in inorganic components such as potassium and phosphorous.

  2. Social Insects Dominate Eastern US Temperate Hardwood Forest Macroinvertebrate Communities in Warmer Regions

    PubMed Central

    King, Joshua R.; Warren, Robert J.; Bradford, Mark A.

    2013-01-01

    Earthworms, termites, and ants are common macroinvertebrates in terrestrial environments, although for most ecosystems data on their abundance and biomass is sparse. Quantifying their areal abundance is a critical first step in understanding their functional importance. We intensively sampled dead wood, litter, and soil in eastern US temperate hardwood forests at four sites, which span much of the latitudinal range of this ecosystem, to estimate the abundance and biomass m−2 of individuals in macroinvertebrate communities. Macroinvertebrates, other than ants and termites, differed only slightly among sites in total abundance and biomass and they were similar in ordinal composition. Termites and ants were the most abundant macroinvertebrates in dead wood, and ants were the most abundant in litter and soil. Ant abundance and biomass m−2 in the southernmost site (Florida) were among the highest values recorded for ants in any ecosystem. Ant and termite biomass and abundance varied greatly across the range, from <1% of the total macroinvertebrate abundance (in the northern sites) to >95% in the southern sites. Our data reveal a pronounced shift to eusocial insect dominance with decreasing latitude in a temperate ecosystem. The extraordinarily high social insect relative abundance outside of the tropics lends support to existing data suggesting that ants, along with termites, are globally the most abundant soil macroinvertebrates, and surpass the majority of other terrestrial animal (vertebrate and invertebrate) groups in biomass m−2. Our results provide a foundation for improving our understanding of the functional role of social insects in regulating ecosystem processes in temperate forest. PMID:24116079

  3. Crossing the pedogenetic threshold: Apparent phosphorus limitation by soil microorganisms in unglaciated acidic eastern hardwood forests

    NASA Astrophysics Data System (ADS)

    Deforest, J. L.; Smemo, K. A.; Burke, D. J.

    2010-12-01

    The availability of soil phosphorus (P) can significantly influence microbial community composition and the ecosystem-level processes they mediate. However, the threshold at which soil microorganisms become functionally P-limited is unclear because of soil acidity effect on P availability. We reason that acidic temperate hardwood forest ecosystems are, in fact, functionally P-limited, but compensation occur via soil microbial production of phosphatase enzymes. We tested this hypothesis in glaciated and unglaciated mature mixed-mesophytic forests in eastern Ohio where both soil pH and P availability had been experientially manipulated. We measured the activity of two P acquiring soil enzymes, phosphomonoesterase (PMono) and phosphodiesterase (PDi), to understand how soil acidity and available P influence microbial function. Our experimental treatments elevated ambient soil pH from below 4.5 to around 5.5 and increased readily available phosphate from 3 to ~25 mg P/kg on glaciated soils and from 0.5 to ~5 mg P/kg on unglaciated soils. The P treatment decreased the activity of PDi by 82% relative to the control on unglaciated soils, but we observed no P treatment effect on glaciated soils. A similar result was observed for PMono. Soil pH, alone, did not significantly influence enzyme activities. Results suggest that soil microorganisms are more likely to be P-limited in older unglaciated soils. However, dramatically higher phosphatase activity in response to very low P availability suggests that an underlying ecosystem P limitation can be ameliorated by soil microbial community dynamics. This mechanism may be more important for older, unglaciated soils that have already crossed a pedogenic threshold where P availability influences ecosystem and microbial function.

  4. Avian response to microclimate in canopy gaps in a bottomland hardwood forest.

    SciTech Connect

    Champlin, Tracey B.; Kilgo, John C.; Gumpertz, Marcia L.; Moorman, Christopher E.

    2009-04-01

    Abstract - Microclimate may infl uence use of early successional habitat by birds. We assessed the relationships between avian habitat use and microclimate (temperature, light intensity, and relative humidity) in experimentally created canopy gaps in a bottomland hardwood forest on the Savannah River Site, SC. Gaps were 2- to 3-year-old group-selection timber harvest openings of three sizes (0.13, 0.26, 0.50 ha). Our study was conducted from spring through fall, encompassing four bird-use periods (spring migration, breeding, post-breeding, and fall migration), in 2002 and 2003. We used mist netting and simultaneously recorded microclimate variables to determine the influence of microclimate on bird habitat use. Microclimate was strongly affected by net location within canopy gaps in both years. Temperature generally was higher on the west side of gaps, light intensity was greater in gap centers, and relative humidity was higher on the east side of gaps. However, we found few relationships between bird captures and the microclimate variables. Bird captures were inversely correlated with temperature during the breeding and postbreeding periods in 2002 and positively correlated with temperature during spring 2003. Captures were high where humidity was high during post-breeding 2002, and captures were low where humidity was high during spring 2003. We conclude that variations in the local microclimate had minor infl uence on avian habitat use within gaps. Instead, habitat selection in relatively mild regions like the southeastern US is based primarily on vegetation structure, while other factors, including microclimate, are less important.

  5. Climate change and the future of natural disturbances in the central hardwood region

    SciTech Connect

    Dale, Virginia H; Hughes, M. Joseph; Hayes, Daniel J

    2015-01-01

    The spatial patterns and ecological processes of the southeastern upland hardwood forests have evolved to reflect past climatic conditions and natural disturbance regimes. Changes in climate can lead to disturbances that exceed their natural range of variation, and the impacts of these changes will depend on the vulnerability or resiliency of these ecosystems. Global Circulation Models generally project annual increases in temperature across the southeastern United States over the coming decades, but changes in precipitation are less consistent. Even more unclear is how climate change might affect future trends in the severity and frequency of natural disturbances, such as severe storms, fires, droughts, floods, and insect outbreaks. Here, we use a time-series satellite data record to map the spatial pattern and severity of broad classes of natural disturbances the southeast region. The data derived from this map allow analysis of regional-scale trends in natural and anthropogenic disturbances in the region over the last three decades. Throughout the region, between 5% and 25% of forest land is affected by some sort of disturbance each year since 1985. The time series reveals periodic droughts that themselves are widespread and of low severity but are associated with more localized, high-severity disturbances such as fire and insect outbreaks. The map also reveals extensive anthropogenic disturbance across the region in the form of forest conversion related to resource extraction and urban and residential development. We discuss how changes in climate and disturbance regimes might affect southeastern forests in the future via altering the exposure, sensitivity and adaptive capacity of these ecosystems. Changes in climate are highly likely to expose southeastern forests to more frequent and severe disturbances, but ultimately how vulnerable or resilient southeastern forests are to these changes will depend on their sensitivity and capacity to adapt to these novel

  6. Mycorrhizal Response to Experimental pH and P Manipulation in Acidic Hardwood Forests

    PubMed Central

    Kluber, Laurel A.; Carrino-Kyker, Sarah R.; Coyle, Kaitlin P.; DeForest, Jared L.; Hewins, Charlotte R.; Shaw, Alanna N.; Smemo, Kurt A.; Burke, David J.

    2012-01-01

    Many temperate forests of the Northeastern United States and Europe have received significant anthropogenic acid and nitrogen (N) deposition over the last century. Although temperate hardwood forests are generally thought to be N-limited, anthropogenic deposition increases the possibility of phosphorus (P) limiting productivity in these forest ecosystems. Moreover, inorganic P availability is largely controlled by soil pH and biogeochemical theory suggests that forests with acidic soils (i.e.,

  7. Canopy gap dynamics of second-growth red spruce-northern hardwood stands in West Virginia

    USGS Publications Warehouse

    Rentch, J.S.; Schuler, T.M.; Nowacki, G.J.; Beane, N.R.; Ford, W.M.

    2010-01-01

    Forest restoration requires an understanding of the natural disturbance regime of the target community and estimates of the historic range of variability of ecosystem components (composition, structure, and disturbance processes). Management prescriptions that support specific restoration activities should be consistent with these parameters. In this study, we describe gap-phase dynamics of even-aged, second-growth red spruce-northern hardwood stands in West Virginia that have been significantly degraded following early Twentieth Century harvesting and wildfire. In the current stage of stand development, gaps tended to be small, with mean canopy gap and extended canopy gap sizes of 53.4m2 and 199.3m2, respectively, and a canopy turnover rate of 1.4%year-1. The majority of gaps resulted from the death of one or two trees. American beech snags were the most frequent gap maker, partially due to the elevated presence of beech-bark disease in the study area. Gaps ranged in age from 1 to 28 years, had a mean of 13 years, and were unimodal in distribution. We projected red spruce to be the eventual gap filler in approximately 40% of the gaps. However, we estimated that most average-sized gaps will close within 15-20 years before red spruce canopy ascension is projected (30-60 years). Accordingly, many understory red spruce will require more than one overhead release - an observation verified by the tree-ring record and consistent with red spruce life history characteristics. Based on our observations, silvicultural prescriptions that include overhead release treatments such as thinning from above or small gap creation through selection harvesting could be an appropriate activity to foster red spruce restoration in the central Appalachians. ?? 2010 Elsevier B.V.

  8. Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

    USGS Publications Warehouse

    Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

    2009-01-01

    Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

  9. Hubbard Brook Ecosystem Study: biogeochemistry of lead in the northern hardwood forest

    SciTech Connect

    Smith, W.; Siccama, T.G.

    1981-09-01

    The average annual Pb input to the northern hardwood forest at the Hubbard Brook Experimental Forest in central New Hampshire was 266 g ha/sup -1/ year /sup -1/ based on 4 years of records. Lead output via streamwater and eroded particulate matter was 5.0 and 1.1 g ha/sup -1/ year/sup -1/, respectively. Lead concentration in precipitation averaged 22 ..mu..g liter/sup -1/ and showed a significant decline over the 4 sample years (1975 to 1978). Lead input to the ecosystem via meteorological vectors is accumulated in the forest floor. Total current Pb content of the forest floor was 8.6 kg ha/sup -1/ and showed no significant differences along the elevation gradient of the watershed (400 to 800 m). Lead concentration in the forest floor was maximum on the ridge due to a minimum forest floor mass relative to the rest of the watershed. Within the forest floor, maximum Pb concentration is in the fermented (F) layer. Total Pb content of the forest biomass (stems greater than or equal to 10 cm dbh) was 1248 g ha/sup -1/. Lead concentration in the biota was in the following order: lichens (213 ..mu..g g/sup -1/) > mosses (190 ..mu..g g/sup -1/) tree twigs (26 ..mu..g g/sup -1/) > roots (20 ..mu..g g/sup -1/) > bark (19 ..mu..g g/sup -1/) > leaves (7 ..mu..g g/sup -1/) = bracket fungi (7 ..mu..g g/sup -1/) > wood (0.7 ..mu..g g/sup -1/). Disturbance of the forest ecosystem through harvest cutting, other than through increased runoff, increased erosion, and transport of particulate matter, does not alter the biogeochemistry of Pb and does not result in increased mobility and export of Pb due to gross or subtle alterations of the behavior of Pb in the ecosystem.

  10. Regional extent of an ecosystem engineer: earthworm invasion in northern hardwood forests.

    PubMed

    Holdsworth, Andrew R; Frelich, Lee E; Reich, Peter B

    2007-09-01

    The invasion of exotic earthworms into northern temperate and boreal forests previously devoid of earthworms is an important driver of ecosystem change. Earthworm invasion can cause significant changes in soil structure and communities, nutrient cycles, and the diversity and abundance of herbaceous plants. However, the regional extent and patterns of this invasion are poorly known. We conducted a regional survey in the Chippewa and Chequamegon National Forests, in Minnesota and Wisconsin, U.S.A., respectively, to measure the extent and patterns of earthworm invasion and their relationship to potential earthworm introduction sites. We sampled earthworms, soils, and vegetation in 20 mature, sugar maple-dominated forest stands in each national forest and analyzed the relationship between the presence of five earthworm taxonomic groups, habitat variables, and distance to the nearest potential introduction site. Earthworm invasion was extensive but incomplete in the two national forests. Four of the six earthworm taxonomic groups occurred in 55-95% of transects; however 20% of all transects were invaded by only one taxonomic group that has relatively minor ecological effects. Earthworm taxonomic groups exhibited a similar sequence of invasion found in other studies: Dendrobaena > Aporrectodea = Lumbricus juveniles > L. rubellus > L. terrestris. Distance to the nearest road was the best predictor of earthworm invasion in Wisconsin while distance to the nearest cabin was the best predictor in Minnesota. These data allow us to make preliminary assessments of landscape patterns of earthworm invasion. As an example, we estimate that 82% of upland mesic hardwood stands in the Wisconsin region are likely invaded by most taxonomic groups while only 3% are unlikely to be invaded at present. Distance to roads and cabins provides a coarse-scale predictor of earthworm invasion to focus stand-level assessments that will help forest managers better understand current and potential

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

    NASA Astrophysics Data System (ADS)

    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

  12. Genome Survey and Characterization of Endophytic Bacteria Exhibiting a Beneficial Effect on Growth and Development of Poplar Trees ▿ †

    PubMed Central

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-01-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides × Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels. PMID:19060168

  13. Successful crossings with early flowering transgenic poplar: interspecific crossings, but not transgenesis, promoted aberrant phenotypes in offspring.

    PubMed

    Hoenicka, Hans; Lehnhardt, Denise; Nilsson, Ove; Hanelt, Dieter; Fladung, Matthias

    2014-10-01

    In forest tree species, the reproductive phase is reached only after many years or even decades of juvenile growth. Different early flowering systems based on the genetic transfer of heat-shock promoter driven flowering-time genes have been proposed for poplar; however, no fertile flowers were reported until now. Here, we studied flower and pollen development in both HSP::AtFT and wild-type male poplar in detail and developed an optimized heat treatment protocol to obtain fertile HSP::AtFT flowers. Anthers from HSP::AtFT poplar flowers containing fertile pollen grains showed arrested development in stage 12 instead of reaching phase 13 as do wild-type flowers. Pollen grains could be isolated under the binocular microscope and were used for intra- and interspecific crossings with wild-type poplar. F1-seedlings segregating the HSP::AtFT gene construct according to Mendelian laws were obtained. A comparison between intra- and interspecific crossings revealed that genetic transformation had no detrimental effects on F1-seedlings. However, interspecific crossings, a broadly accepted breeding method, produced 47% seedlings with an aberrant phenotype. The early flowering system presented in this study opens new possibilities for accelerating breeding of poplar and other forest tree species. Fast breeding and the selection of transgene-free plants, once the breeding process is concluded, can represent an attractive alternative even under very restrictive regulations. PMID:24975279

  14. The Lipoxygenase Gene Family in Poplar: Identification, Classification, and Expression in Response to MeJA Treatment

    PubMed Central

    Chen, Zhu; Chen, Xue; Yan, Hanwei; Li, Weiwei; Li, Yuan; Cai, Ronghao; Xiang, Yan

    2015-01-01

    Background Lipoxygenases (LOXs) are important dioxygenases in cellular organisms. LOXs contribute to plant developmental processes and environmental responses. However, a systematic and comprehensive analysis has not been focused on the LOX gene family in poplar. Therefore, in the present study, we performed a comprehensive analysis of the LOX gene family in poplar. Results Using bioinformatics methods, we identified a total of 20 LOX genes. These LOX genes were clustered into two subfamilies. The gene structure and motif composition of each subfamily were relatively conserved. These genes are distributed unevenly across nine chromosomes. The PtLOX gene family appears to have expanded due to high tandem and low segmental duplication events. Microarray analysis showed that a number of PtLOX genes have different expression pattern across disparate tissues and under various stress treatments. Quantitative real-time PCR (qRT-PCR) analysis was further performed to confirm the responses to MeJA treatment of the 20 poplar LOX genes. The results show that the PtLOX genes are regulated by MeJA (Methyl jasmonate) treatment. Conclusions This study provides a systematic analysis of LOX genes in poplar. The gene family analysis reported here will be useful for conducting future functional genomics studies to uncover the roles of LOX genes in poplar growth and development. PMID:25928711

  15. Long-term effects of a lock and dam and greentree reservoir management on a bottomland hardwood forest

    USGS Publications Warehouse

    King, S.L.; Allen, J.A.; McCoy, J.W.

    1998-01-01

    We investigated the long-term effects of a lock and dam and greentree reservoir management on a riparian bottomland hardwood forest in southern Arkansas, USA, by monitoring stress, mortality, and regeneration of bottomland hardwood trees in 53 permanent sampling plots from 1987-1995. The lock and dam and greentree reservoir management have altered the timing, depth, and duration of flooding within the wetland forest. Evaluation of daily river stage data indicates that November overbank flooding (i.e. 0.3 m above normal pool) of 1 week duration occurred only 10 times from 1950 to 1995 and four of these occurrences were the result of artificial flooding of the greentree reservoir. Results of the vegetation study indicate that the five most common dominant and co-dominant species were overcup oak, water hickory, Nuttall oak, willow oak, and sweetgum. Mortality of willow oak exceeded that of all other species except Nuttall oak. Nuttall oak, willow oak, and water hickory had much higher percentages of dead trees concentrated within the dominant and co-dominant crown classes. Probit analysis indicated that differences in stress and mortality were due to a combination of flooding and stand competition. Overcup oak appears to exhibit very little stress regardless of crown class and elevation and, with few exceptions, had a significantly greater probability of occurring within lower stress classes than any other species. Only 22 new stems were recruited into the 5 cm diameter-at-breast height size class between 1990-1995 and of these, three were Nuttall oak, three were water hickory, and one was sweetgum. No recruitment into the 5 cm diameter-at-breast height size class occurred for overcup oak or willow oak. The results of the study suggest that the forest is progressing to a more water-tolerant community dominated by overcup oak. A conservative flooding strategy would minimize tree stress and maintain quality wildlife habitat within the forested wetland.The long

  16. Differential response by hardwood and deciduous stands in New England forests to climate change and insect-induced mortality

    NASA Astrophysics Data System (ADS)

    Munger, J. William; Wofsy, Steven C.; Orwig, David A.; Williams, Chris

    2016-04-01

    Forests in the northeastern United States include large areas dominated by mosaics of oak/maple and hemlock stands. Often the hardwood dominated stands include a significant cohort of hemlock saplings. However, long-term survival of hemlock in this region is threatened by Hemlock Wooly Adelgid (HWA), an invasive insect that is fatal to eastern hemlock. The northern limit of HWA is affected in part by winter minimum temperature and warmer winters are enabling northward expansion of HWA infestation. At the Harvard Forest in central Massachusetts, two long-term eddy flux towers are measuring carbon exchange in a >100 year old hardwood stand since 1992 (EMS- Ha1) and in a 100-200 year old hemlock stand (Ha2) since 2004. The flux measurements are complemented by vegetation dynamics plots. Carbon exchange at the two sites has distinctly different seasonality. The hardwood site has a shorter carbon uptake period, but higher peak fluxes, while the hemlock stand has a long carbon uptake period extending from spring thaw until early winter freeze. Some contribution from the evergreen hemlock in the understory is evident before canopy greenup at the EMS tower and spring and fall carbon uptake rates have been increasing and contribute in part to a trend towards larger annual carbon uptake at this site. Carbon uptake by hemlock increases with warmer temperatures in the spring and fall transition. Adelgids have reached the hemlock stand near Ha2 and have been widely distributed in the canopy since spring of 2012. The hemlock canopy in that stand is thinning and net carbon uptake and evapotranspiration have been decreasing since 2012. Adelgids have also been observed in scattered stands near the Ha1 tower, but as of 2015 the trees are still healthy. Because hemlocks stands have different seasonality and provide a distinct soil and sub-canopy light environment, their mortality and replacement by hardwood species will have significant impacts on forest dynamics, carbon balance, and

  17. Establishing even-aged pine and pine-hardwood mixtures in the Ouachita mountains using the shelterwood method

    SciTech Connect

    Shelton, M.G.; Baker, J.B.

    1992-01-01

    The study was established in 1989 as a joint effort among the Ouachita National Forest, the Southern Forest Experiment Station, and the University of Arkansas at Monticello. The goals of the study are: (1) to determine the levels at which pine and hardwoods are compatible in the shelterwood regeneration method by evaluating the amount, spatial distribution and development of regeneration and measuring the growth and yield of the retained seedtrees, (2) determine the damage to regeneration caused by the eventual seedtree harvest, and (3) to evaluate the wildlife habitat, water quality, and aesthetics of shelterwood stands so that comparisons can be made with uneven-aged stands.

  18. Identification and Analysis of the Acetylated Status of Poplar Proteins Reveals Analogous N-Terminal Protein Processing Mechanisms with Other Eukaryotes

    PubMed Central

    Liu, Chang-Cai; Zhu, Hang-Yong; Dong, Xiu-Mei; Ning, De-Li; Wang, Hong-Xia; Li, Wei-Hua; Yang, Chuan-Ping; Wang, Bai-Chen

    2013-01-01

    Background The N-terminal protein processing mechanism (NPM) including N-terminal Met excision (NME) and N-terminal acetylation (Nα-acetylation) represents a common protein co-translational process of some eukaryotes. However, this NPM occurred in woody plants yet remains unknown. Methodology/Principal Findings To reveal the NPM in poplar, we investigated the Nα-acetylation status of poplar proteins during dormancy by combining tandem mass spectrometry with TiO2 enrichment of acetylated peptides. We identified 58 N-terminally acetylated (Nα-acetylated) proteins. Most proteins (47, >81%) are subjected to Nα-acetylation following the N-terminal removal of Met, indicating that Nα-acetylation and NME represent a common NPM of poplar proteins. Furthermore, we confirm that poplar shares the analogous NME and Nα-acetylation (NPM) to other eukaryotes according to analysis of N-terminal features of these acetylated proteins combined with genome-wide identification of the involving methionine aminopeptidases (MAPs) and N-terminal acetyltransferase (Nat) enzymes in poplar. The Nα-acetylated reactions and the involving enzymes of these poplar proteins are also identified based on those of yeast and human, as well as the subcellular location information of these poplar proteins. Conclusions/Significance This study represents the first extensive investigation of Nα-acetylation events in woody plants, the results of which will provide useful resources for future unraveling the regulatory mechanisms of Nα-acetylation of proteins in poplar. PMID:23536812

  19. A heterogeneous boron distribution in soil influences the poplar root system architecture development

    NASA Astrophysics Data System (ADS)

    Rees, R.; Robinson, B. H.; Hartmann, S.; Lehmann, E.; Schulin, R.

    2009-04-01

    Poplars are well suited for the phytomanagement of boron (B)-contaminated sites, due to their high transpiration rate and tolerance to elevated soil B concentrations. However, the uptake and the fate of B in poplar stands are not well understood. This information is crucial to improve the design of phytomanagement systems, where the primary role of poplars is to reduce B leaching by reducing the water flux through the contaminated material. Like other trace elements, B occurs heterogeneously in soils. Concentrations can differ up to an order of magnitude within centimetres. These gradients affect plant root growth and thus via preferential flow along the roots water and mass transport in soils to ground and surface waters. Generally there are three possible reactions of plant roots to patches with elevated trace element concentrations in soils: indifference, avoidance, or foraging. While avoidance or indifference might seem to be the most obvious strategies, foraging cannot be excluded a priori, because of the high demand of poplars for B compared to other tree species. We aimed to determine the rooting strategies of poplars in soils where B is either homo- or heterogeneously distributed. We planted 5 cm cuttings of Populus tremula var. Birmensdorf clones in aluminum (Al) containers with internal dimensions of 64 x 67 x 1.2 cm. The soil used was subsoil from northern Switzerland with a naturally low B and organic C concentration. We setup two treatments and a control with three replicates each. We spiked a bigger and a smaller portion of the soil with the same amount of B(OH)3-salt, in order to obtain soil concentrations of 7.5 mg B kg-1 and 20 mg B kg-1. We filled the containers with (a) un-spiked soil, (b) the 7.5 mg B kg-1 soil and (c) heterogeneously. The heterogeneous treatment consisted of one third 20 mg B kg-1 soil and two thirds control soil. We grew the poplars in a small greenhouse over 2 months and from then on in a climate chamber for another 3 months

  20. Point counts of birds in bottomland hardwood forests of the Mississippi Alluvial Valley: Duration, minimal sample size, and points versus visits

    USGS Publications Warehouse

    Smith, W.P.; Twedt, D.J.; Wiedenfeld, D.A.; Hamel, P.B.; Ford, R.P.; Cooper, R.J.

    1993-01-01

    The purpose of the research was to evaluate the efficacy of point count surveys in bottomland hardwood forests. The specific objectives were to determine: (1) whether the recommended distance measures for point count circular plots are useful in bottomland hardwood forests, (2) the optimum duration for each point count, (3) the optimum number of points to sample at each locality, (4) the optimum number of counts at each point during a season, and (5) the minimum sample size to accomodate the variation in bird species distribution and relative abundance throughout the lower MAV.

  1. Enhanced enzymatic hydrolysis of poplar bark by combined use of gamma ray and dilute acid for bioethanol production

    NASA Astrophysics Data System (ADS)

    Chung, Byung Yeoup; Lee, Jae Taek; Bai, Hyoung-Woo; Kim, Ung-Jin; Bae, Hyeun-Jong; Gon Wi, Seung; Cho, Jae-Young

    2012-08-01

    Pretreatment of poplar bark with a combination of sulfuric acid (3%, w/w, H2SO4) and gamma irradiation (0-1000 kGy) was performed in an attempt to enhance enzymatic hydrolysis for bioethanol production. The yields of reducing sugar were slightly increased with an increasing irradiation dose, ranging from 35.4% to 51.5%, with a 56.1% reducing sugar yield observed after dilute acid pretreatment. These results clearly showed that soluble sugars were released faster and to a greater extent in dilute acid-pretreated poplar bark than in gamma irradiation-pretreated bark. When combined pretreatment was carried out, a drastic increase in reducing sugar yield (83.1%) was found compared with individual pretreatment, indicating the possibility of increasing the convertibility of poplar bark following combined pretreatment. These findings are likely associated with cellulose crystallinity, lignin modification, and removal of hemicelluloses.

  2. QTLs for Woolly Poplar Aphid (Phloeomyzus passerinii L.) Resistance Detected in an Inter-Specific Populus deltoides x P. nigra Mapping Population

    PubMed Central

    Carletti, Giorgia; Carra, Andrea; Allegro, Gianni; Vietto, Lorenzo; Desiderio, Francesca; Bagnaresi, Paolo; Gianinetti, Alberto; Cattivelli, Luigi; Valè, Giampiero; Nervo, Giuseppe

    2016-01-01

    The genus Populus represents one of the most economically important groups of forest trees. It is composed by approximately 30 species used for wood and non-wood products, phytoremediation and biomass. Poplar is subjected to several biological and environmental threats although, compared to annual crops, we know far less about the genetic bases of biotic stress resistance. Woolly poplar aphid (Phloeomyzus passerinii) is considered a main pest of cultivated poplars in European and American countries. In this work we present two high density linkage maps in poplar obtained by a genotyping by sequencing (GBS) approach and the identification of QTLs involved in Ph. passerinii resistance. A total of 5,667 polymorphic markers (5,606 SNPs and 61 SSRs) identified on expressed sequences have been used to genotype 131 plants of an F1 population P ×canadensis obtained by an interspecific mate between Populus deltoides (resistant to woolly poplar aphid) and Populus nigra (susceptible to woolly poplar aphid). The two linkage maps, obtained following the two-way pseudo-testcross mapping strategy, have been used to investigate the genetic bases of woolly poplar aphid resistance. One major QTL and two QTLs with minor effects (mapped on LGV, LGXVI and LG XIX) explaining the 65.8% of the genetic variance observed in the progeny in response to Ph. passerinii attack were found. The high density coverage of functional markers allowed the identification of three genes belonging to disease resistance pathway as putative candidates for P. deltoides resistance to woolly poplar aphid. This work is the first report on genetic of woolly poplar aphid genetic resistance and the resistant loci associated markers identified represent a valuable tool in resistance poplar breeding programs. PMID:27022954

  3. QTLs for Woolly Poplar Aphid (Phloeomyzus passerinii L.) Resistance Detected in an Inter-Specific Populus deltoides x P. nigra Mapping Population.

    PubMed

    Carletti, Giorgia; Carra, Andrea; Allegro, Gianni; Vietto, Lorenzo; Desiderio, Francesca; Bagnaresi, Paolo; Gianinetti, Alberto; Cattivelli, Luigi; Valè, Giampiero; Nervo, Giuseppe

    2016-01-01

    The genus Populus represents one of the most economically important groups of forest trees. It is composed by approximately 30 species used for wood and non-wood products, phytoremediation and biomass. Poplar is subjected to several biological and environmental threats although, compared to annual crops, we know far less about the genetic bases of biotic stress resistance. Woolly poplar aphid (Phloeomyzus passerinii) is considered a main pest of cultivated poplars in European and American countries. In this work we present two high density linkage maps in poplar obtained by a genotyping by sequencing (GBS) approach and the identification of QTLs involved in Ph. passerinii resistance. A total of 5,667 polymorphic markers (5,606 SNPs and 61 SSRs) identified on expressed sequences have been used to genotype 131 plants of an F1 population P ×canadensis obtained by an interspecific mate between Populus deltoides (resistant to woolly poplar aphid) and Populus nigra (susceptible to woolly poplar aphid). The two linkage maps, obtained following the two-way pseudo-testcross mapping strategy, have been used to investigate the genetic bases of woolly poplar aphid resistance. One major QTL and two QTLs with minor effects (mapped on LGV, LGXVI and LG XIX) explaining the 65.8% of the genetic variance observed in the progeny in response to Ph. passerinii attack were found. The high density coverage of functional markers allowed the identification of three genes belonging to disease resistance pathway as putative candidates for P. deltoides resistance to woolly poplar aphid. This work is the first report on genetic of woolly poplar aphid genetic resistance and the resistant loci associated markers identified represent a valuable tool in resistance poplar breeding programs. PMID:27022954

  4. Searching for hot spots and hot moments of soil denitrification in northern hardwood forests

    NASA Astrophysics Data System (ADS)

    Morse, J. L.; Duran, J.; Morillas, L.; Roales, J.; Bailey, S. W.; McGuire, K. J.; Groffman, P. M.

    2014-12-01

    Denitrification is a key biogeochemical process that affects nitrogen (N) availability, N losses to aquatic systems, and atmospheric chemistry. In upland forests, denitrification has not been thought to be a major N pathway because it is an anaerobic microbial process that requires nitrate, labile carbon (C), and low oxygen (O2) conditions, which do not occur broadly or consistently throughout forest soils. However, there may be enough spatial and temporal heterogeneity at fine scales to support denitrification rates that are relevant at the landscape scale. To quantify the importance of spatial and temporal variability in soil denitrification in northern hardwood forests at the Hubbard Brook Experimental Forest (HBEF; New Hampshire, USA), we developed two related projects: 1) we sought to identify hot spots of biogeochemical activity, including soil denitrification potential, based on hydropedologic settings and flowpaths in a catchment during the growing season; and 2) we investigated the influence of simulated rainfall events on soil O2 and nitrous oxide concentrations, denitrification rates, and soil respiration during different seasons at HBEF. In the first study, we expected to find that sites dominated by soils with thick Bh horizons (zones of C accumulation) would have the highest denitrification rates. However, despite the variation among soil profiles found in different hydropedologic settings, we did not find significant differences in denitrification potential. Rather, when areal coverage and horizon thickness for the contrasting hydropedologic settings were accounted for, catchment-scale estimates of denitrification potential were about 1/3 higher than conventionally calculated estimates. In the second study, soil O2 in surface horizons only decreased following additions of labile C. Responses of soil respiration and denitrification to simulated rainfall were also influenced by season. While these studies highlight the complex heterogeneity in forest

  5. Nitrogen immobilization by wood-chip application: Protecting water quality in a northern hardwood forest

    USGS Publications Warehouse

    Homyak, P.M.; Yanai, R.D.; Burns, Douglas A.; Briggs, R.D.; Germain, R.H.

    2008-01-01

    Forest harvesting disrupts the nitrogen cycle, which may affect stream water quality by increasing nitrate concentrations, reducing pH and acid neutralizing capacity, and mobilizing aluminum and base cations. We tested the application of wood chips derived from logging slash to increase immobilization of N after harvesting, which should reduce nitrate flux to streams. In August 2004, a stand of northern hardwoods was patch-clearcut in the Catskill Mountains, NY, and four replicates of three treatments were implemented in five 0.2-ha cut patches. Wood chips were applied to the soil surface at a rate equivalent to the amount of slash smaller than eight inches in diameter (1?? treatment). A second treatment doubled that rate (2??), and a third treatment received no chips (0??). Additionally, three uncut reference plots were established in nearby forested areas. Ion exchange resin bags and soil KCl-extractions were used to monitor nitrate availability in the upper 5-10 cm of soil approximately every seven weeks, except in winter. Resin bags indicated that the wood chips retained 30% or 42% of the nitrate pulse, while for KCl extracts, the retention rate was 78% or 100% of the difference between 0?? and uncut plots. During the fall following harvest, wood-chip treated plots had resin bag soil nitrate concentrations about 25% of those in 0?? plots (p = 0.0001). In the first growing season after the cut, nitrate concentrations in wood-chip treated plots for KCl extracts were 13% of those in 0?? treatments (p = 0.03) in May and about half those in 0?? treatments (p = 0.01) in July for resin bags. During spring snowmelt, however, nitrate concentrations were high and indistinguishable among treatments, including the uncut reference plots for resin bags and below detection limit for KCl extracts. Wood chips incubated in litterbags had an initial C:N of 125:1, which then decreased to 70:1 after one year of field incubation. These changes in C:N values indicate that the wood

  6. Sample size and allocation of effort in point count sampling of birds in bottomland hardwood forests

    USGS Publications Warehouse

    Smith, W.P.; Twedt, D.J.; Cooper, R.J.; Wiedenfeld, D.A.; Hamel, P.B.; Ford, R.P.

    1995-01-01

    To examine sample size requirements and optimum allocation of effort in point count sampling of bottomland hardwood forests, we computed minimum sample sizes from variation recorded during 82 point counts (May 7-May 16, 1992) from three localities containing three habitat types across three regions of the Mississippi Alluvial Valley (MAV). Also, we estimated the effect of increasing the number of points or visits by comparing results of 150 four-minute point counts obtained from each of four stands on Delta Experimental Forest (DEF) during May 8-May 21, 1991 and May 30-June 12, 1992. For each stand, we obtained bootstrap estimates of mean cumulative number of species each year from all possible combinations of six points and six visits. ANOVA was used to model cumulative species as a function of number of points visited, number of visits to each point, and interaction of points and visits. There was significant variation in numbers of birds and species between regions and localities (nested within region); neither habitat, nor the interaction between region and habitat, was significant. For a = 0.05 and a = 0.10, minimum sample size estimates (per factor level) varied by orders of magnitude depending upon the observed or specified range of desired detectable difference. For observed regional variation, 20 and 40 point counts were required to accommodate variability in total individuals (MSE = 9.28) and species (MSE = 3.79), respectively, whereas ? 25 percent of the mean could be achieved with five counts per factor level. Sample size sufficient to detect actual differences of Wood Thrush (Hylocichla mustelina) was >200, whereas the Prothonotary Warbler (Protonotaria citrea) required <10 counts. Differences in mean cumulative species were detected among number of points visited and among number of visits to a point. In the lower MAV, mean cumulative species increased with each added point through five points and with each additional visit through four visits

  7. Foraging behavior of pileated woodpeckers in partial cut and uncut bottomland hardwood forest

    USGS Publications Warehouse

    Newell, P.; King, Sammy L.; Kaller, Michael D.

    2009-01-01

    In bottomland hardwood forests, partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife like Louisiana black bear (Ursus americanus luteolus), white-tailed deer (Odocoileus virginianus), and Neotropical migrants. Although partial cutting may be beneficial to some species, those that use dead wood may be negatively affected since large diameter and poor quality trees (deformed, moribund, or dead) are rare, but normally targeted for removal. On the other hand, partial cutting can create dead wood if logging slash is left on-site. We studied foraging behavior of pileated woodpeckers (Dryocopus pileatus) in one- and two-year-old partial cuts designed to benefit priority species and in uncut forest during winter, spring, and summer of 2006 and 2007 in Louisiana. Males and females did not differ in their use of tree species, dbh class, decay class, foraging height, use of foraging tactics or substrate types; however, males foraged on larger substrates than females. In both partial cut and uncut forest, standing live trees were most frequently used (83% compared to 14% for standing dead trees and 3% for coarse woody debris); however, dead trees were selected (i.e. used out of proportion to availability). Overcup oak (Quercus lyrata) and bitter pecan (Carya aquatica) were also selected and sugarberry (Celtis laevigata) avoided. Pileated woodpeckers selected trees >= 50 cm dbh and avoided trees in smaller dbh classes (10-20 cm). Density of selected foraging substrates was the same in partial cut and uncut forest. Of the foraging substrates, woodpeckers spent 54% of foraging time on live branches and boles, 37% on dead branches and boles, and 9% on vines. Of the foraging tactics, the highest proportion of foraging time was spent excavating (58%), followed by pecking (14%), gleaning (14%), scaling (7%), berry-eating (4%), and probing (3%). Woodpecker use of foraging tactics and substrates, and foraging height and substrate

  8. Foraging behavior of pileated woodpeckers in partial cut and uncut bottomland hardwood forest

    USGS Publications Warehouse

    Newell, P.; King, S.; Kaller, M.

    2009-01-01

    In bottomland hardwood forests, partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife like Louisiana black bear (Ursus americanus luteolus), white-tailed deer (Odocoileus virginianus), and Neotropical migrants. Although partial cutting may be beneficial to some species, those that use dead wood may be negatively affected since large diameter and poor quality trees (deformed, moribund, or dead) are rare, but normally targeted for removal. On the other hand, partial cutting can create dead wood if logging slash is left on-site. We studied foraging behavior of pileated woodpeckers (Dryocopus pileatus) in one- and two-year-old partial cuts designed to benefit priority species and in uncut forest during winter, spring, and summer of 2006 and 2007 in Louisiana. Males and females did not differ in their use of tree species, dbh class, decay class, foraging height, use of foraging tactics or substrate types; however, males foraged on larger substrates than females. In both partial cut and uncut forest, standing live trees were most frequently used (83% compared to 14% for standing dead trees and 3% for coarse woody debris); however, dead trees were selected (i.e. used out of proportion to availability). Overcup oak (Quercus lyrata) and bitter pecan (Carya aquatica) were also selected and sugarberry (Celtis laevigata) avoided. Pileated woodpeckers selected trees ???50 cm dbh and avoided trees in smaller dbh classes (10-20 cm). Density of selected foraging substrates was the same in partial cut and uncut forest. Of the foraging substrates, woodpeckers spent 54% of foraging time on live branches and boles, 37% on dead branches and boles, and 9% on vines. Of the foraging tactics, the highest proportion of foraging time was spent excavating (58%), followed by pecking (14%), gleaning (14%), scaling (7%), berry-eating (4%), and probing (3%). Woodpecker use of foraging tactics and substrates, and foraging height and substrate

  9. Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms.

    PubMed

    Suárez, Esteban R; Fahey, Timothy J; Yavitt, Joseph B; Groffman, Peter M; Bohlen, Patrick J

    2006-02-01

    A field study was conducted to evaluate the effects of exotic earthworm invasions on the rates of leaf litter disappearance in a northern hardwood forest in southcentral New York, USA. Specifically, we assessed whether differences in litter quality and the species composition of exotic earthworm communities affected leaf litter disappearance rates. Two forest sites with contrasting communities of exotic earthworms were selected, and disappearance rates of sugar maple and red oak litter were estimated in litter boxes in adjacent earthworm-free, transition, and earthworm-invaded plots within each site. After 540 days in the field, 1.7-3 times more litter remained in the reference plots than in the earthworm-invaded plots. In the earthworm-invaded plots, rates of disappearance of sugar maple litter were higher than for oak litter during the first year, but by the end of the experiment, the amount of sugar maple and oak litter remaining in the earthworm-invaded plots was identical within each site. The composition of the earthworm communities significantly affected the patterns of litter disappearance. In the site dominated by the anecic earthworm Lumbricus terrestris and the endogeic Aporrectodea tuberculata, the percentage of litter remaining after 540 days (approximately 17%) was significantly less than at the site dominated by L. rubellus and Octolasion tyrtaeum (approximately 27%). This difference may be attributed to the differences in feeding behavior of the two litter-feeding species: L. terrestris buries entire leaves in vertical burrows, whereas L. rubellus usually feeds on litter at the soil surface, leaving behind leaf petioles and veins. Our results showed that earthworms not only accelerate litter disappearance rates, but also may reduce the differences in decomposition rates that result from different litter qualities at later stages of decay. Similarly, our results indicate that earthworm effects on decomposition vary with earthworm community

  10. Soil Carbon Turnover and the Net Ecosystem Carbon Balance of a Northern Hardwood Forest, Michigan, USA

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Biswas, S.; Vogel, C. S.; Curtis, P. S.

    2004-12-01

    Soils are a major reservoir of stored carbon (C) in forested ecosystems, containing up to 70% of total ecosystem C. Heterotrophic activity largely dictates the rate of soil C turnover and directly impacts ecosystem C balance. Reliable estimates of net ecosystem productivity (NEP) from ecophysiological and biometric data as well as the refinement of process-based models predicting belowground changes in C storage depend on accurate quantification and partitioning of autotrophic and heterotrophic soil C fluxes. We used field and laboratory measurements of root, microbial and soil respiration in a northern hardwood forest to (1) quantify the annual soil C efflux attributed to heterotrophs and autotrophs from 1999 to 2003; (2) identify the extent to which microclimatic drivers impact interannual variability in microbial activity of the mineral soil and O-horizon; and (3) evaluate the sensitivity of estimated annual NEP to heterotrophic respiration. The study was conducted in an 85-year-old aspen-dominated mixed deciduous forest at the University of Michigan Biological Station Ameriflux site (UMBS ˜Flux) in N. lower Michigan, USA. Soil respiration was monitored from 1999 to 2003. Laboratory incubations of roots, mineral soil and the O-horizon at different temperatures were used to examine the relationship between microclimate and autotrophic and heterotrophic respiration. Empirical models relating root and microbial respiration to temperature were used in combination with soil respiration models and site soil temperature, moisture and root biomass data to estimate the contribution of autotrophic and heterotrophic respiration to total soil C efflux. Heterotrophic soil respiration estimates were combined with other C flux data to calculate annual NEP from 1999 to 2003. Microbially-mediated C turnover was responsible for ˜half of the total annual soil C efflux. Heterotrophic respiration varied by more than 1 Mg C ha-1 yr-1 among years primarily due to interannual

  11. Consequences of landscape patterns on the genetic composition of remnant hardwood stands in the Southeast: A pilot study.

    SciTech Connect

    Godt, Mary Jo, W.; Hamrick, J., L.

    2003-01-01

    Report of a pilot study intended to generate genetic data for a tree species in fragmented hardwood stands. It was anticipated that this data would permit assessment of the feasibility of long-term genetic research for which external funding support could be generated. A second objective was to initiate studies that addressed fundamental questions of how landscape structure, in conjunction with the population dynamics and reproductive characteristics of the tree species, influences genetic structure and long-term viability of hardwood forest stands on the Savannah River Site and in similar southeastern landscapes. Fragmentation of plant habitats can result in small, genetically isolated populations. Spatial isolation and small population size may have several consequences, including reduced reproduction, increased inbreeding and the stochastic loss of genetic variability. Such losses of genetic and genotypic diversity can reduce plant fitness and may diminish population viability. Deleterious genetic effects resulting from small population sizes can be ameliorated by gene flow via pollen and seed into fragmented populations.

  12. The Hardwood Gneiss: Evidence for high P-T Archean metamorphism in the southern province of the Lake Superior region

    SciTech Connect

    Peterson, J.W. ); Geiger, C.A. )

    1990-03-01

    The Hardwood Gneiss is an areally small unit of Precambrian granulite-grade rocks exposed in the Archean gneiss terrane of the southern Lake Superior region. The rocks are located in the southwestern portion of the Upper Peninsula of Michigan and consist of a structurally conformable package of quartzitic, metapelitic, amphibolitic, and metabasic units. Three texturally distinct garnet types are present in the metabasites and are interpreted to represent two metamorphic events. Geothermobarometry indicates conditions of {approximately}8.2-11.6 kbar and {approximately}770C for M1, and conditions of {approximately}6.0-10.1 kbar and {approximately}610-740C for M2. It is proposed that M1 was Archean and contemporaneous with a high-grade metamorphic event recorded in the Minnesota River Valley. The M2 event was probably Early Proterozoic and pre-Penokean, with metamorphic conditions more intense than those generally ascribed to the Penokean Orogeny in Michigan, but similar to the conditions reported for the Kapuskasing zone of Ontario. The high paleopressures and temperatures of the M1 event make the Hardwood Gneiss distinct from any rocks previously described in the southern Lake Superior region, and suggest intense tectonic activity during the Archean.

  13. Bio-oil production of softwood and hardwood forest industry residues through fast and intermediate pyrolysis and its chromatographic characterization.

    PubMed

    Torri, Isadora Dalla Vecchia; Paasikallio, Ville; Faccini, Candice Schmitt; Huff, Rafael; Caramão, Elina Bastos; Sacon, Vera; Oasmaa, Anja; Zini, Claudia Alcaraz

    2016-01-01

    Bio-oils were produced through intermediate (IP) and fast pyrolysis (FP), using Eucalyptus sp. (hardwood) and Picea abies (softwood), wood wastes produced in large scale in Pulp and Paper industries. Characterization of these bio-oils was made using GC/qMS and GC×GC/TOFMS. The use of GC×GC provided a broader characterization of bio-oils and it allowed tracing potential markers of hardwood bio-oil, such as dimethoxy-phenols, which might co-elute in 1D-GC. Catalytic FP increased the percentage of aromatic hydrocarbons in P. abies bio-oil, indicating its potential for fuel production. However, the presence of polyaromatic hydrocarbons (PAH) draws attention to the need of a proper management of pyrolysis process in order to avoid the production of toxic compounds and also to the importance of GC×GC/TOFMS use to avoid co-elutions and consequent inaccuracies related to identification and quantification associated with GC/qMS. Ketones and phenols were the major bio-oil compounds and they might be applied to polymer production. PMID:26556402

  14. Propagation of Some Local Fig (Ficus carica L.) Cultivars by Hardwood Cuttings under the Field Conditions in Tunisia

    PubMed Central

    Aljane, Fateh; Nahdi, Sabrine

    2014-01-01

    This research was carried out in Southeast of Tunisia in 2009 and 2010, in order to study the propagation of six (Ficus carica L.) cultivars by using hardwood cuttings under the field conditions. The effect of the cultivars and the type of buds, shoots age, shoots length, and shoots diameter were recorded. Ten cuttings per cultivar and/or cutting types with three replications were planted in rooting unit. Percentage of root emergence and six morphological parameters of young fig plants were measured. Results showed that the responses of cuttings as fig nursery plants presented a high variability among the five cultivars. The most widely varied characters were % root emergence (RE) and cumulative growth of young plant (CG). The first one ranged from 10% to 90%, the second varied within 32 and 112 cm. Concerning the ‘‘BITHER” cultivar, 6 cutting types with different age, length, and diameter were evaluated. Results showed a great variation in % of root emergence (0–90%), length of nursery plant (3–77 cm), and number of roots/nursery plant (0–29 roots). The present research showed that the hardwood cutting of local fig cultivars can be propagated under field conditions in Southeast of Tunisia.

  15. VOC emissions of Grey poplar leaves as affected by salt stress and different N sources.

    PubMed

    Teuber, M; Zimmer, I; Kreuzwieser, J; Ache, P; Polle, A; Rennenberg, H; Schnitzler, J-P

    2008-01-01

    Nitrogen nutrition and salt stress experiments were performed in a greenhouse with hydroponic-cultured, salt-sensitive Grey poplar (Populus x canescens) plants to study the combined influence of different N sources (either 1 mm NO(3) (-) or NH(4)(+)) and salt (up to 75 mm NaCl) on leaf gas exchange, isoprene biosynthesis and VOC emissions. Net assimilation and transpiration proved to be highly sensitive to salt stress and were reduced by approximately 90% at leaf sodium concentrations higher than 1,800 microg Na g dry weight (dw)(-1). In contrast, emissions of isoprene and oxygenated VOC (i.e. acetaldehyde, formaldehyde and acetone) were unaffected. There was no significant effect of combinations of salt stress and N source, and neither NO(3)(-) or NH(4)(+) influenced the salt stress response in the Grey poplar leaves. Also, transcript levels of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PcDXR) and isoprene synthase (PcISPS) did not respond to the different N sources and only responded slightly to salt application, although isoprene synthase (PcISPS) activity was negatively affected at least in one of two experiments, despite high isoprene emission rates. A significant salt effect was the strong reduction of leaf dimethylallyl diphosphate (DMADP) content, probably due to restricted availability of photosynthates for DMADP biosynthesis. Further consequences of reduced photosynthetic gas exchange and maintaining VOC emissions are a very high C loss, up to 50%, from VOC emissions related to net CO(2) uptake and a strong increase in leaf internal isoprene concentrations, with maximum mean values up to 6.6 microl x l(-1). Why poplar leaves maintain VOC biosynthesis and emission under salt stress conditions, despite impaired photosynthetic CO(2) fixation, is discussed. PMID:18211549

  16. Growth and physiological responses of isohydric and anisohydric poplars to drought.

    PubMed

    Attia, Ziv; Domec, Jean-Christophe; Oren, Ram; Way, Danielle A; Moshelion, Menachem

    2015-07-01

    Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (gs), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (Kleaf) and E: isohydric plants reduced Kleaf, gs, and E, whereas anisohydric genotypes maintained high Kleaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (Kplant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample water and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed. PMID:25954045

  17. Hypoxia Affects Nitrogen Uptake and Distribution in Young Poplar (Populus × canescens) Trees

    PubMed Central

    Liu, Bin; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2015-01-01

    The present study with young poplar trees aimed at characterizing the effect of O2 shortage in the soil on net uptake of NO3- and NH4+ and the spatial distribution of the N taken up. Moreover, we assessed biomass increment as well as N status of the trees affected by O2 deficiency. For this purpose, an experiment was conducted in which hydroponically grown young poplar trees were exposed to hypoxic and normoxic (control) conditions for 14 days. 15N-labelled NO3- and NH4+ were used to elucidate N uptake and distribution of currently absorbed N and N allocation rates in the plants. Whereas shoot biomass was not affected by soil O2 deficiency, it significantly reduced root biomass and, consequently, the root-to-shoot ratio. Uptake of NO3- but not of NH4+ by the roots of the trees was severely impaired by hypoxia. As a consequence of reduced N uptake, the N content of all poplar tissues was significantly diminished. Under normoxic control conditions, the spatial distribution of currently absorbed N and N allocation rates differed depending on the N source. Whereas NO3- derived N was mainly transported to the younger parts of the shoot, particularly to the developing and young mature leaves, N derived from NH4+ was preferentially allocated to older parts of the shoot, mainly to wood and bark. Soil O2 deficiency enhanced this differential allocation pattern. From these results we assume that NO3- was assimilated in developing tissues and preferentially used to maintain growth and ensure plant survival under hypoxia, whereas NH4+ based N was used for biosynthesis of storage proteins in bark and wood of the trees. Still, further studies are needed to understand the mechanistic basis as well as the eco-physiological advantages of such differential allocation patterns. PMID:26308462

  18. Analysis of the impact of biomechanical traits of European black Poplar on riverbank flow resistance

    NASA Astrophysics Data System (ADS)

    Battista Chirico, Giovanni; Saulino, Luigi; Pasquino, Vittorio; Villani, Paolo; Rita, Angelo; Todaro, Luigi; Saracino, Antonio

    2016-04-01

    Predicting the effects of riparian plants on river flow dynamics is fundamental for an appropriate river management. Riparian woody vegetation enhances bank cohesion and provides ecosystem services by mitigating nutrient and sediment loads to the river flow and enhancing biodiversity. However riparian trees also contribute to river flow resistance and thus can have a significant impact on flow dynamics during flood events. The flow-plant interaction mainly depends on plant morphological characters (e.g. diameter, height, canopy size, foliage density) and biomechanical properties, such as its flexural rigidity. This study aims at testing the hypothesis that the hydrodynamic behaviour of the European black Poplar (∖textit{Populus nigra} L.), a common woody riparian plant, is influenced by specific biomechanical traits developed as result of its adaptation to different river ecosystems. We examine the morphological and biomechanical properties of living stems of black Poplar sampled in two different riverine environments in Southern Italy located only a few kilometres apart. The two sample sets of living stems exhibit similar morphological traits but significantly different Young module of elasticity. We compared the drag forces that the flow would exert on these two different sets of plants for a wide range of flow velocities, by employing a numerical model that accounts for the bending behaviour of the woody plant due to the hydrodynamic load, under the hypothesis of complete submergence. A Monte Carlo approach was applied in order to account for the stochastic variability of the morphological and mechanical parameters affecting plant biomechanical behaviour. We identified a threshold value of the plant diameter, above which the two sets of European black Poplars are subjected to drag forces that differ by more than 25{∖%} on average, for flow velocities larger than 1 m/s.

  19. Growth and physiological responses of isohydric and anisohydric poplars to drought

    PubMed Central

    Attia, Ziv; Domec, Jean-Christophe; Oren, Ram; Way, Danielle A.; Moshelion, Menachem

    2015-01-01

    Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P. balsamifera x simonii (BSxSI, anisohydric genotype) were studied to assess the physiological basis for biomass accumulation and water-use efficiency across a range of water availabilities. Under ample water, whole plant stomatal conductance (gs), transpiration (E), and growth rates were higher in anisohydric genotypes (SI and BSxSI) than in isohydric poplars (BS). Under drought, all genotypes regulated the leaf to stem water potential gradient via changes in gs, synchronizing leaf hydraulic conductance (Kleaf) and E: isohydric plants reduced Kleaf, gs, and E, whereas anisohydric genotypes maintained high Kleaf and E, which reduced both leaf and stem water potentials. Nevertheless, SI poplars reduced their plant hydraulic conductance (Kplant) during water stress and, unlike, BSxSI plants, recovered rapidly from drought. Low gs of the isohydric BS under drought reduced CO2 assimilation rates and biomass potential under moderate water stress. While anisohydric genotypes had the fastest growth under ample water and higher photosynthetic rates under increasing water stress, isohydric poplars had higher water-use efficiency. Overall, the results indicate three strategies for how closely related biomass species deal with water stress: survival-isohydric (BS), sensitive-anisohydric (BSxSI), and resilience-anisohydric (SI). Implications for woody biomass growth, water-use efficiency, and survival under variable environmental conditions are discussed. PMID:25954045

  20. Challenging synergistic activity of poplar-bacteria association for the Cd phytostabilization.

    PubMed

    C, Cocozza; D, Trupiano; G, Lustrato; G, Alfano; D, Vitullo; A, Falasca; T, Lomaglio; V, De Felice; G, Lima; G, Ranalli; S, Scippa; R, Tognetti

    2015-12-01

    The synergistic activity between plants and microorganisms may contribute to the implementation of proactive management strategies in the stabilization of contaminated sites, although heavy metals, such as cadmium (Cd), are potentially toxic to them. The aim of this study was to evaluate the degree of tolerance to Cd contamination (supplying twice 40 mg kg(-1) of Cd) in poplar cuttings [clone I-214, P. × euramericana (Dode) Guinier] inoculated or not with two concentrations of Serratia marcescens strain (1 × 10(7) CFU/g and 2 × 10(7) CFU/g of potting mix). The response of the plant-bacteria system to excess Cd was investigated with special reference to the structural traits of plants and the functional efficiency of bacteria. Bacterial colonization and substrate components were previously assessed in order to define the best solution for formulating the experimental plant growth media. The tested plant-bacteria association, especially when bacteria were provided in double concentration, stimulated specific tolerance mechanisms to Cd through the promotion of the poplar growth. Inoculated plants produced larger leaves and increased stem diameter, while roots grew longer and wider in Cd-treated plants. The effect of bacterial inoculum on plant growth traits and metal partitioning in plant organs was assessed in order to define the potential of this poplar clone to be a suitable candidate for phytostabilization of Cd-contaminated soil. The final effect of the inoculation with bacteria, which alleviated the metal load and Cd phytotoxicity due to their bioaccumulation ability, suggests promising phytostabilization potential of these plant-bacteria associations. PMID:26268621

  1. Transgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera.

    PubMed

    Boeckler, G Andreas; Towns, Megan; Unsicker, Sybille B; Mellway, Robin D; Yip, Lynn; Hilke, Ines; Gershenzon, Jonathan; Constabel, C Peter

    2014-02-01

    Transgenic hybrid aspen (Populus tremula x tremuloides) overexpressing the MYB134 tannin regulatory gene show dramatically enhanced condensed tannin (proanthocyanidin) levels, as well as shifts in other phenolic metabolites. A series of insect bioassays with forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar) caterpillars was carried out to determine how this metabolic shift affects food preference and performance of generalist tree-feeding lepidopterans. Both species showed a distinct preference for the high-tannin MYB134 overexpressor plants, and L. dispar performance was enhanced relative to controls. L. dispar reached greater pupal weight and showed reduced time to pupation when reared on the MYB134 overexpressing poplar. These results were unexpected since enhanced condensed tannin levels were predicted to act as feeding deterrents. However, the data may be explained by the observed decrease in the salicinoids (phenolic glycosides) salicortin and tremulacin that accompanied the upregulation of the condensed tannins in the transgenics. We conclude that for these two lepidopteran species, condensed tannin levels are unlikely to be a major determinant of caterpillar food preference or performance. However, our experiments show that overexpression of a single regulatory gene in transgenic aspen can have a significant impact on herbivorous insects. PMID:24496605

  2. Antisense Down-Regulation of 4CL Expression Alters Lignification, Tree Growth, and Saccharification Potential of Field-Grown Poplar1[W][OA

    PubMed Central

    Voelker, Steven L.; Lachenbruch, Barbara; Meinzer, Frederick C.; Jourdes, Michael; Ki, Chanyoung; Patten, Ann M.; Davin, Laurence B.; Lewis, Norman G.; Tuskan, Gerald A.; Gunter, Lee; Decker, Stephen R.; Selig, Michael J.; Sykes, Robert; Himmel, Michael E.; Kitin, Peter; Shevchenko, Olga; Strauss, Steven H.

    2010-01-01

    Transgenic down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been reported as a means for reducing lignin content in cell walls and increasing overall growth rates, thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplar (Populus tremula × Populus alba), we applied this strategy and examined field-grown transformants for both effects on wood biochemistry and tree productivity. The reductions in lignin contents obtained correlated well with 4CL RNA expression, with a sharp decrease in lignin amount being observed for RNA expression below approximately 50% of the nontransgenic control. Relatively small lignin reductions of approximately 10% were associated with reduced productivity, decreased wood syringyl/guaiacyl lignin monomer ratios, and a small increase in the level of incorporation of H-monomers (p-hydroxyphenyl) into cell walls. Transgenic events with less than approximately 50% 4CL RNA expression were characterized by patches of reddish-brown discolored wood that had approximately twice the extractive content of controls (largely complex polyphenolics). There was no evidence that substantially reduced lignin contents increased growth rates or saccharification potential. Our results suggest that the capacity for lignin reduction is limited; below a threshold, large changes in wood chemistry and plant metabolism were observed that adversely affected productivity and potential ethanol yield. They also underline the importance of field studies to obtain physiologically meaningful results and to support technology development with transgenic trees. PMID:20729393

  3. An identification of the East Fork Poplar Creek floodplain, Anderson and Roane Counties, Tennessee

    SciTech Connect

    1992-12-01

    The work in this report was conducted by the US Army Corps of Engineers, Nashville District, during the period November 1991 through July 1992. The purpose of this study is to identify the East Fork Poplar Creek (EFPC) floodplain. This information is required as part of the remedial action plans for removal or containment of contamination within the EFPC floodplain. EFPC and a portion of its floodplain have been contaminated as a result of operations and accidental releases at the Department of Energy`s Y-12 Plant. Mercury is the major contaminant found in EFPC and its floodplain.

  4. Remedial investigation/feasibility study of the Clinch River/Poplar Creek operable unit. Volume 5

    SciTech Connect

    1996-03-01

    This volume is in support of the findings of an investigation into contamination of the Clinch River and Poplar Creek near the Oak Ridge Reservation (for more than 50 years, various hazardous and radioactive substances have been released to the environment as a result of operations and waste management activities there). It addresses the quality assurance objectives for measuring the data, presents selected historical data, contains data from several discrete water characterization studies, provides data supporting the sediment characterization, and contains data related to several biota characterization studies.

  5. Best management practices plan for the Lower East Fork Poplar Creek Operable Unit, Oak Ridge, Tennessee

    SciTech Connect

    1996-04-01

    This plan was prepared in support of the Phase II Remedial Design Report (DOE/OR/01-1449&D1) and in accordance with requirements under CERCLA to present the plan for best management practices to be followed during the remediation. This document provides the Environmental Restoration Program with information about spill prevention and control, water quality monitoring, good housekeeping practices, sediment and erosion control measures, and inspections and environmental compliance practices to be used during Phase II of the remediation project for the Lower East Fork Poplar Creek Operable Unit.

  6. Variations in the morphology of wood structure can explain why hardwood species of similar density have very different resistances to impact and compressive loading.

    PubMed

    Hepworth, David G; Vincent, J F V; Stringer, G; Jeronimidis, G

    2002-02-15

    A clear relationship has been established between the impact resistance and density of softwoods. However, there are hardwood species that have the same density but very different impact resistance. Softwoods are largely composed of tracheid cells (30-50 microm across); hardwoods have smaller fibre cells and also contain vessels (50-500 microm across). We examined white oak, beech, hickory and spruce. Compressive deformation was identified as the main mechanism for energy absorption in the type of impact test used. The disparate size of different wood cells in the hardwoods results in heterogeneous compressive deformation. During compression, large vessels cause smaller surrounding cells to be deformed more than in regions without vessels, increasing the energy absorbed. However, vessels that are too close together initiate kink banding at low loads and less energy is absorbed. The different morphologies of hardwoods are probably responsible for the variation in impact resistance between species of similar density. Drilling small holes along the grain of spruce, which naturally lacks vessels, mimicked the effect of vessels and did not reduce the energy-absorbing capabilities of the wood, despite the density being reduced. These findings could be used to increase the energy-absorbing capacity of synthetic foam materials. PMID:16210180

  7. Comparison of hardwood and softwood dust-induced expression of cytokines and chemokines in mouse macrophage RAW 264.7 cells.

    PubMed

    Määttä, Juha; Luukkonen, Ritva; Husgafvel-Pursiainen, Kirsti; Alenius, Harri; Savolainen, Kai

    2006-01-20

    Numerous epidemiological studies have shown that occupational exposure to wood dust can induce several respiratory diseases such as allergic rhinitis, chronic bronchitis, asthma, and sino-nasal adenocarcinoma. However, comparison of the harmful potential of different wood dust species on the basis of epidemiological studies is complicated because in the occupational environment workers are usually exposed to several wood dust species simultaneously. In the present study, we have characterized and compared the effects of two hardwood dusts, beech and teak, and two softwood dusts, pine and spruce, on cytokine and chemokine expression utilizing an in vitro model, murine macrophage cell line RAW 264.7. The expression patterns of selected cytokines and chemokines were assessed by real-time quantitative PCR and by ELISA. All the tested hardwood and softwood dusts induced TNF-alpha expression and inhibited IL-1beta expression. Similarly, all the wood dusts induced the expression of CCL2, CCL3, CCL4, and CXCL2/3 chemokines and inhibited CCL24 expression. Our results indicate that both hardwood and softwood dusts influence the cytokine and chemokine expression of RAW 264.7 cells. Although some differences could be detected in the magnitude of responses to different wood dust species, the two tested wood dust groups, hardwoods and softwoods, have quite similar effects on cytokine and chemokine expression in RAW 264.7 cell line. PMID:16202497

  8. A Threshold Relation Between Harvest Intensity and Stream Chemistry in a Northern Hardwood Forest of the Northeastern U.S.

    NASA Astrophysics Data System (ADS)

    Burns, D. A.; Murdoch, P. S.

    2006-12-01

    Clearcutting of northern hardwood forests in mountainous landscapes of the northeastern U.S. has been shown to cause large increases in stream nitrate (NO3-) concentrations accompanied by increased stream acidity, elevated losses of nutrient base cations, and aluminum concentrations sufficient to be toxic to brook trout. An 18 ha clearcut in the Catskill Mountains of southeastern New York, USA in 1997 resulted in stream NO3- concentrations that peaked at > 1,000 μmol L-1, and base cation (Ca2+, Mg2+, K+) concentrations that increased by more than three-fold during the first year after harvest. In contrast, previous timber-stand improvement harvests in 1995 and 1996 in which < 10% of tree basal area was removed from watersheds, resulted in no measurable change in stream water chemistry. Based on an analysis of these previous data, we hypothesized that there is likely a harvest threshold for changes in stream-water chemistry below which only minimal and tolerable changes in water quality occur. We tested this hypothesis by completing four forest harvests during 2002 to 2006 in which varying amounts of basal area were removed from northern hardwood forest plots and watersheds. These results have shown that at a basal area removal of about 33%, stream NO3- and K+ concentrations increased, but less than proportionally to the concentration changes observed after the clearcut. Calcium and Mg2+ concentrations increased as well, but these changes were about proportional to the concentration changes observed after the clearcut. Additionally, stream NO3- concentrations returned to background values within two years at the 33% partial harvest compared to about eight years in the clearcut. Soil-water lysimeter data from two other harvests in which 30 and 50% of basal area were removed from hardwood forest plots are consistent with that of the previous partial harvest. Nitrate concentrations increased less than proportionally to the changes observed after the clearcut, and

  9. Mineral Soil Carbon in Managed Hardwood Forests of the Northeastern US

    NASA Astrophysics Data System (ADS)

    Vario, C.; Friedland, A.; Hornig, C.

    2013-12-01

    New England is characterized by extensive forest cover and large reservoirs of soil carbon (C). In northern hardwood forests, mineral soil C can account for up to 50% of total ecosystem C. There has been an increasing demand for forests to serve both as a C sink and a renewable energy source, and effective management of the ecosystem C balance relies on accurate modeling of each compartment of the ecosystem. However, the dynamics of soil C storage with respect to forest use are variable and poorly understood, particularly in mineral soils. For example, current regional models assume C pools after forest harvesting do not change, while some studies suggest that belowground mineral soil C pools can be affected by disturbances at the soil surface. We quantified mineral soil C pools in previously clear-cut stands in seven research or protected forests across New York, New Hampshire, Massachusetts, and Vermont. The ages of the sites sampled ranged from recently cleared to those with no disturbance history, with 21 forest stands represented in the study. Within each research forest studied, physical parameters such as soil type, forest type, slope and land-use history (aside from forest harvest) did not vary between the stands of different ages. Soil samples were collected to a depth of 60 cm below the mineral-organic boundary using a gas-powered augur and 9.5-cm diameter drill bit. Samples were collected in 10-cm increments in shallow mineral soil and 15-cm increments from 30-60 cm depth. Carbon, nitrogen (N), pH, texture and soil mineralogy were measured across the regional sites. At Bartlett Experimental Forest (BEF) in New Hampshire, mineral soil biogeochemistry in cut and uncut sites was studied at a finer scale. Measurements included soil temperature to 55 cm depth, carbon compound analyses using Py-GCMS and soil microbial messenger RNA extractions from mineral soil. Finally, we simulated C dynamics after harvesting by building a model in Stella, with a particular

  10. Quantifying the Role of Bottomland Hardwood Forest Flood Attenuation in the Central U.S

    NASA Astrophysics Data System (ADS)

    Hubbart, J. A.; Bulliner, E. A.; Freeman, G. W.; Scollan, D. P.; Romine, J.; Chinnasamy, P.; Huang, D.; Schulz, J.

    2010-12-01

    Contemporary floodplain management is a growing concern, particularly in regions where climate change predictions include increased precipitation such as the central U.S. and Missouri. Historically, bottomland hardwood forests (BHF) played a significant role in runoff and flood attenuation. However, most of the floodplain BHF in Missouri was removed in the 19th and 20th centuries to cultivate the rich underlying soils. In many instances, BHF conversion required the installation of drainage and flood control structures, such as drainage tiles, ditches, levees, and dams. Many stream and river channels were straightened and enlarged to further reduce flooding. Structural changes, coupled with changes in vegetation and soils, drastically altered the hydrology of streams, floodplains, and the remnant BHF. Today, century-old management practices are coming under scrutiny in the Midwest in terms of management efficacy in contemporary urbanizing watersheds. Therefore, work is being conducted in central Missouri to quantify current floodplain flow attenuation of a 303(d) listed impaired urban stream. Instrumentation was installed in lower reaches of the Hinkson Creek Watershed (230km2) in the spring of 2010 in a case study comparing a remnant BHF and an abandoned agricultural floodplain site using replicated study designs. Instrumentation includes two 80 m2 grids of nine equally spaced four meter deep piezometers to monitor groundwater flow and volumetric water content (VWC) sensor profiles that monitor VWC at 15, 30, 50, 75 and 100 cm depth. Grids were enlarged to 120 m2 to measure leaf area index (LAI), surface infiltration capacity with double ring infiltrometers, and soil characteristics. Soil characteristics were quantified by extracting soil cores at soil depths of 0, 15, 30, 50, 75 and 100 cm (n = 302). LAI in the BHF was on average 3.06 (SD = 0.65, min = 1.31, max = 4.38, n = 42). Preliminary analysis indicates that average infiltration capacity is 44 cm/hr (SD = 38

  11. Phenolic Profiling of Caffeic Acid O-Methyltransferase-Deficient Poplar Reveals Novel Benzodioxane Oligolignols1

    PubMed Central

    Morreel, Kris; Ralph, John; Lu, Fachuang; Goeminne, Geert; Busson, Roger; Herdewijn, Piet; Goeman, Jan L.; Van der Eycken, Johan; Boerjan, Wout; Messens, Eric

    2004-01-01

    Caffeic acid O-methyltransferase (COMT) catalyzes preferentially the methylation of 5-hydroxyconiferaldehyde to sinapaldehyde in monolignol biosynthesis. Here, we have compared HPLC profiles of the methanol-soluble phenolics fraction of xylem tissue from COMT-deficient and control poplars (Populus spp.), using statistical analysis of the peak heights. COMT down-regulation results in significant concentration differences for 25 of the 91 analyzed peaks. Eight peaks were exclusively detected in COMT-deficient poplar, of which four could be purified for further identification using mass spectrometry/mass spectrometry, nuclear magnetic resonance, and spiking of synthesized reference compounds. These new compounds were derived from 5-hydroxyconiferyl alcohol or 5-hydroxyconiferaldehyde and were characterized by benzodioxane moieties, a structural type that is also increased in the lignins of COMT-deficient plants. One of these four benzodioxanes amounted to the most abundant oligolignol in the HPLC profile. Furthermore, all of the differentially accumulating oligolignols involving sinapyl units were either reduced in abundance or undetectable. The concentration levels of all identified oligolignols were in agreement with the relative supply of monolignols and with their chemical coupling propensities, which supports the random coupling hypothesis. Chiral HPLC analysis of the most abundant benzodioxane dimer revealed the presence of both enantiomers in equal amounts, indicating that they were formed by radical coupling reactions under simple chemical control rather than guided by dirigent proteins. PMID:15563622

  12. Tulip-poplar leaf diffusion resistance calculated from stomatal dimensions and varying environmental parameters

    SciTech Connect

    McConathy, R.K.

    1983-03-01

    The study describes the gradients of stomatal size and density in the crown of a mature forest-grown tulip-poplar (Liriodendron tulipifera L.) in eastern Tennessee. These data are used to predict leaf resistance to vapor diffusion in relation to stomatal width and boundary layer resistance. Stomatal density on individual leaves did not vary, but density increased with increasing crown height. Stomatal size decreased with increasing height of leaves within the crown. Stomatal size and density variations interacted to result in a constant number of stomata per leaf at all crown heights. Stomatal diffusive resistance values calculated from stomatal measurements and varying environmental parameters indicated that stomatal resistance controlled transpiration water losses only at small apertures (<0.6 ..mu..m). Boundary layer resistance was controlling at large stomatal apertures (>0.6 ..mu..m) and at low wind speeds (approx.100 cm/s). Under normal forest conditions tulip-poplar stomatal resistance exercised more control over transpiration than did boundary layer resistance.

  13. Profiling of Oligolignols Reveals Monolignol Coupling Conditions in Lignifying Poplar Xylem1[w

    PubMed Central

    Morreel, Kris; Ralph, John; Kim, Hoon; Lu, Fachuang; Goeminne, Geert; Ralph, Sally; Messens, Eric; Boerjan, Wout

    2004-01-01

    Lignin is an aromatic heteropolymer, abundantly present in the walls of secondary thickened cells. Although much research has been devoted to the structure and composition of the polymer to obtain insight into lignin polymerization, the low-molecular weight oligolignol fraction has escaped a detailed characterization. This fraction, in contrast to the rather inaccessible polymer, is a simple and accessible model that reveals details about the coupling of monolignols, an issue that has raised considerable controversy over the past years. We have profiled the methanol-soluble oligolignol fraction of poplar (Populus spp.) xylem, a tissue with extensive lignification. Using liquid chromatography-mass spectrometry, chemical synthesis, and nuclear magnetic resonance, we have elucidated the structures of 38 compounds, most of which were dimers, trimers, and tetramers derived from coniferyl alcohol, sinapyl alcohol, their aldehyde analogs, or vanillin. All structures support the recently challenged random chemical coupling hypothesis for lignin polymerization. Importantly, the structures of two oligomers, each containing a γ-p-hydroxybenzoylated syringyl unit, strongly suggest that sinapyl p-hydroxybenzoate is an authentic precursor for lignin polymerization in poplar. PMID:15516504

  14. Enhanced bioethanol production from yellow poplar by deacetylation and oxalic acid pretreatment without detoxification.

    PubMed

    Kundu, Chandan; Lee, Hong-Joo; Lee, Jae-Won

    2015-02-01

    In order to produce ethanol from yellow poplar, deacetylation was performed using sodium hydroxide (NaOH). Optimal deacetylation conditions were determined by a response surface methodology. The highest acetic acid concentration obtained was 7.06 g/L when deacetylation was performed at 60 °C for 80 min with 0.8% NaOH. Acetic acid was recovered by electrodialysis from the deacetylated hydrolysate. The oxalic acid pretreatment of deacetylated biomass was carried out and the hydrolysate directly used for ethanol production without detoxification. Ethanol yields ranged from 0.34 to 0.47 g/g and the highest ethanol yield was obtained when pretreatment was carried out at 150 °C with 50 mM oxalic acid. The highest ethanol concentration obtained from pretreated biomass was 27.21 g/L at 170 °C, using a 50 mM of oxalic acid for the simultaneous saccharification and fermentation (SSF). Overall, 20.31 g of ethanol was obtained by hydrolysate and SSF from 100 g of deacetylated yellow poplar. PMID:25205056

  15. Herbivore-induced volatile emission in black poplar: regulation and role in attracting herbivore enemies.

    PubMed

    Clavijo McCormick, Andrea; Irmisch, Sandra; Reinecke, Andreas; Boeckler, G Andreas; Veit, Daniel; Reichelt, Michael; Hansson, Bill S; Gershenzon, Jonathan; Köllner, Tobias G; Unsicker, Sybille B

    2014-08-01

    After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts. PMID:24471487

  16. Does glutathione metabolism have a role in the defence of poplar against zinc excess?

    PubMed

    Di Baccio, Daniela; Kopriva, Stanislav; Sebastiani, Luca; Rennenberg, Heinz

    2005-07-01

    Transition metals such as zinc (Zn) are essential micronutrients for many physiological processes, but they become toxic at elevated levels. Zinc is one of the most abundant trace heavy metals present in agro-ecosystems. Populus spp. have been suggested as good candidates for using to study the removal and/or immobilization of environmental organic and inorganic pollutants. In order to understand the physiological and biochemical bases of this assumption for Zn, plants of Populus deltoides x P. nigra (P. x euramericana) were grown in hydroponics with different concentrations of Zn [1 microm (control), and 1, 5 and 10 mm] in the nutrient solution.Shoot biomass decreased at 5 and 10 mm Zn, while the Zn content of young leaves increased progressively with increasing Zn concentration (1-10 mm). Total glutathione (GSH+GSSG) content was reduced with increasing Zn concentration, while the contribution of oxidized to total glutathione increased. Despite these observations, semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that the gene expression of GSH reductase (GR, chloroplastic and cytosolic isoform) and gamma-glutamylcysteine synthetase (gamma-ECS) increased in young leaves of poplars treated with excess Zn. We conclude that GSH synthesis, consumption and redox status play a central role in the response of poplars to high concentrations of Zn. PMID:15948831

  17. Tryptamine-induced resistance in tryptophan decarboxylase transgenic poplar and tobacco plants against their specific herbivores.

    PubMed

    Gill, Rishi I S; Ellis, Brian E; Isman, Murray B

    2003-04-01

    The presence of amines and their derivatives in plant tissues is known to influence insect feeding and reproduction. The enzyme tryptophan decarboxylase (TDC) catalyzes the decarboxylation of tryptophan to tryptamine, which is both a bioactive amine and a precursor of other indole derivatives. Transgenic poplar and tobacco plants ectopically expressing TDC1 accumulated elevated levels of tryptamine without affecting plant growth and development. This accumulation was consistently associated with adverse effects on feeding behavior and physiology of Malacosoma disstria Hub. (forest tent caterpillar, FTC) and Manduca sexta L. (tobacco hornworm, THW). Behavior studies with FTC and THW larvae showed that acceptability of the leaf tissue to larvae was inversely related to foliar tryptamine levels. Physiological studies with FTC and THW larvae showed that consumption of leaf tissue from the transgenic lines is deleterious to larvae growth, apparently due to a postingestive mechanism. Thus, ectopic expression of TDC1 can allow sufficient tryptamine to accumulate in poplar and tobacco leaf tissue to suppress significantly the growth of insect pests that normally feed on these plants. PMID:12775143

  18. Physical and chemical characteristics of products from the torrefaction of yellow poplar (Liriodendron tulipifera).

    PubMed

    Kim, Young-Hun; Lee, Soo-Min; Lee, Hyoung-Woo; Lee, Jae-Won

    2012-07-01

    We investigated the characteristics of torrefied yellow poplar (Liriodendron tulipifera) depending on reaction time (30 min) and temperature (240-280 °C). The thermogravimetric, grindability and calorific value of torrefied biomass were analyzed. As the torrefaction temperature increased, the carbon content of torrefied biomass increased from 49.50% to 54.42%, while the hydrogen and oxygen contents decreased from 6.09% to 5.65% and 28.71% to 26.61%, respectively. The highest calorific value was 1233 kJ/kg when torrefaction was performed at 280 °C for 30 min. An overall increase in energy density and decrease in mass and energy yield was observed with the increase in torrefaction temperature. The analysis of thermal decomposition demonstrated that the hemicelluloses contained in torrefied biomass decreased with increasing torrefaction temperature, whereas cellulose and lignin were only slightly affected. The grindability of torrefied biomass was significantly improved when torrefaction was performed at high temperature. Torrefaction of yellow poplar improved the chemical and physical fuel properties of the biomass. PMID:22609665

  19. Over-expression of poplar transcription factor ERF76 gene confers salt tolerance in transgenic tobacco.

    PubMed

    Yao, Wenjing; Wang, Lei; Zhou, Boru; Wang, Shengji; Li, Renhua; Jiang, Tingbo

    2016-07-01

    Ethylene response factors (ERFs) belong to a large plant-specific transcription factor family, which play a significant role in plant development and stress responses. Poplar ERF76 gene, a member of ERF TF family, can be up-regulated in response to salt stress, osmotic stress, and ABA treatment. The ERF76 protein was confirmed to be targeted preferentially in the nucleus of onion cell by particle bombardment. In order to understand the functions of ERF76 gene in salt stress response, we conducted temporal and spatial expression analysis of ERF76 gene in poplar. Then the ERF76 cDNA fragment containing an ORF was cloned from di-haploid Populus simonii×P. nigra and transferred into tobacco (Nicotiana tobacum) genome by Agrobacterium-mediated leaf disc method. Under salt stress, transgenic tobacco over-expressing ERF76 gene showed a significant increase in seed germination rate, plant height, root length, and fresh weight, as well as in relative water content (RWC), superoxide dismutase (SOD) activity, peroxidase (POD) activity, and proline content, compared to control tobacco lines. In contrast, transgenic tobacco lines displayed a decrease in malondialdehyde (MDA) accumulation, relative electrical conductivity (REC) and reactive oxygen species (ROS) accumulation in response to salt stress, compared to control tobacco lines. Over all, the results indicated that ERF76 gene plays a critical role in salt tolerance in transgenic tobacco. PMID:27123829

  20. The Oak Ridge Y-12 Plant biological monitoring and abatement program for East Fork Poplar Creek

    SciTech Connect

    Loar, J.M.; Adams, S.M.; Allison, L.J.; Giddings, J.M.; McCarthy, J.F.; Southworth, G.R.; Smith, J.G.; Stewart, A.J.; Springborn Bionomics, Inc., Wareham, MA; Oak Ridge National Lab., TN )

    1989-10-01

    In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Y-12 Plant, a nuclear weapons components production facility located in Oak Ridge, Tennessee, and operated by Martin Marietta Energy Systems, Inc., for the US Department of Energy. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Oak Ridge Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek), in particular, the growth and propagation of fish and aquatic life, as designated by the Tennessee Department of Health and Environment. A second purpose for the BMAP is to document the ecological effects resulting from implementation of a water pollution control program that will include construction of nine new wastewater treatment facilities over the next 4 years. Because of the complex nature of the effluent discharged to East Fork Poplar Creek and the temporal and spatial variability in the composition of the effluent (i.e., temporal variability related to various pollution abatement measures that will be implemented over the next several years and spatial variability caused by pollutant inputs downstream of the Oak Ridge Y-12 Plant), a comprehensive, integrated approach to biological monitoring was developed for the BMAP. 39 refs., 5 figs., 8 tabs.

  1. Comparative Sugar Recovery and Fermentation Data Following Pretreatment of Poplar Wood by Leading Technologies

    SciTech Connect

    Wyman, C. E.; Dale, B. E.; Elander, R. T.; Holtzapple, M.; Ladisch, M. R.; Lee, Y. Y.; Mitchinson, C.; Saddler, J. N.

    2009-01-01

    Through a Biomass Refining Consortium for Applied Fundamentals and Innovation among Auburn University, Dartmouth College, Michigan State University, the National Renewable Energy Laboratory, Purdue University, Texas A&M University, the University of British Columbia, and the University of California at Riverside, leading pretreatment technologies based on ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, lime, neutral pH, and sulfur dioxide were applied to a single source of poplar wood, and the remaining solids from each technology were hydrolyzed to sugars using the same enzymes. Identical analytical methods and a consistent material balance methodology were employed to develop comparative performance data for each combination of pretreatment and enzymes. Overall, compared to data with corn stover employed previously, the results showed that poplar was more recalcitrant to conversion to sugars and that sugar yields from the combined operations of pretreatment and enzymatic hydrolysis varied more among pretreatments. However, application of more severe pretreatment conditions gave good yields from sulfur dioxide and lime, and a recombinant yeast strain fermented the mixed stream of glucose and xylose sugars released by enzymatic hydrolysis of water washed solids from all pretreatments to ethanol with similarly high yields. An Agricultural and Industrial Advisory Board followed progress and helped steer the research to meet scientific and commercial needs.

  2. Genome-wide identification and in silico analysis of poplar peptide deformylases.

    PubMed

    Liu, Chang-Cai; Liu, Bao-Guang; Yang, Zhi-Wei; Li, Chun-Ming; Wang, Bai-Chen; Yang, Chuan-Ping

    2012-01-01

    Peptide deformylases (PDF) behave as monomeric metal cation hydrolases for the removal of the N-formyl group (Fo). This is an essential step in the N-terminal Met excision (NME) that occurs in these proteins from eukaryotic mitochondria or chloroplasts. Although PDFs have been identified and their structure and function have been characterized in several herbaceous species, it remains as yet unexplored in poplar. Here, we report on the first identification of two genes (PtrPDF1A and PtrPDF1B) respectively encoding two putative PDF polypeptides in Populus trichocarpa by genome-wide investigation. One of them (XP_002300047.1) encoded by PtrPDF1B (XM_002300011.1) was truncated, and then revised into a complete sequence based on its ESTs support with high confidence. We document that the two PDF1s of Populus are evolutionarily divergent, likely as a result of independent duplicated events. Furthermore, in silico simulations demonstrated that PtrPDF1A and PtrPDF1B should act as similar PDF catalytic activities to their corresponding PDF orthologs in Arabidopsis. This result would be value of for further assessment of their biological activities in poplar, and further experiments are now required to confirm them. PMID:22606033

  3. Ozone exposure and flux-based response functions for photosynthetic traits in wheat, maize and poplar.

    PubMed

    Bagard, Matthieu; Jolivet, Yves; Hasenfratz-Sauder, Marie-Paule; Gérard, Joëlle; Dizengremel, Pierre; Le Thiec, Didier

    2015-11-01

    Ozone exposure- and dose-response relationships based on photosynthetic leaf traits (CO2 assimilation, chlorophyll content, Rubisco and PEPc activities) were established for wheat, maize and poplar plants grown in identical controlled conditions, providing a comparison between crop and tree species, as well as between C3 and C4 plants. Intra-specific variability was addressed by comparing two wheat cultivars with contrasting ozone tolerance. Depending on plant models and ozone levels, first-order, second-order and segmented linear regression models were used to derive ozone response functions. Overall, flux-based functions appeared superior to exposure-based functions in describing the data, but the improvement remained modest. The best fit was obtained using the POD0.5 for maize and POD3 for poplar. The POD6 appeared relevant for wheat, although intervarietal differences were found. Our results suggest that taking into account the dynamics of leaf antioxidant capacity could improve current methods for ozone risk assessment for plants. PMID:26253315

  4. An investigation of shallow ground-water quality near East Fork Poplar Creek, Oak Ridge, Tennessee

    USGS Publications Warehouse

    Carmichael, J.K.

    1989-01-01

    Alluvial soils of the flood plain of East Fork Poplar Creek in Oak Ridge, Tennessee, are contaminated with mercury and other metals, organic compounds, and radio-nuclides originating from the Y-12 Plant, a nuclear-processing facility located within the U.S. Department of Energy 's Oak Ridge Reservation. Observation wells were installed in the shallow aquifer of the flood plain, and water quality samples were collected to determine if contaminants are present in the shallow groundwater. Groundwater in the shallow aquifer occurs under water-table conditions. Recharge is primarily from precipitation and discharge is to East Fork Poplar Creek. Groundwater levels fluctuate seasonally in response to variations in recharge and evapotranspiration. During extremely dry periods, the water table drops below the base of the shallow aquifer in some flood-plain areas. Contaminants found in water samples from several of the wells in concentrations which equaled or exceeded drinking-water standards established by the U.S. Environmental Protection Agency are antimony, chromium, lead, mercury, selenium, phenols, and strontium-90. Total and dissolved uranium concentrations exceeded the analytical detection limit in nearly 70% of the wells in the flood plain. The results of water quality determinations demonstrate that elevated concentrations of most trace metals (and possibly organic compounds and radionuclides) were caused by contaminated sediments in the samples. The presence of contaminated sediment in samples is suspected to be the result of borehole contamination during well installation. (USGS)

  5. Novel method to determine element concentrations in foliage of poplar and willow cuttings.

    PubMed

    Evangelou, Michael W H; Bürgi, Annina; Robinson, Brett H; Günthardt-Goerg, Madeleine S; Schöngens, Marcel; Schulin, Rainer

    2016-09-01

    Measuring the uptake of the chemical elements by plants usually requires the destructive harvest of the plants. Analyzing individual leaves is unsatisfactory because their elemental concentration depends on their age and position on the branch or stem. We aimed to find an easy method to determine the elemental concentrations using a few suitable single leaves along the main shoot of poplar (Populus monviso) and willow (Salix viminalis) cuttings at the end of the first season. Using Ca, Cd, Mn, Fe, K, P, Pb, and Zn concentrations, measured in selected leaves along the main shoots of the cuttings, mathematical functions were derived, which described best their distribution. Elemental allocation patterns were independent of the soil characteristics and soil element concentrations. Based on these functions, three leaves from specific positions along the main shoot were selected, which could accurately describe the derived functions. The deviation of the calculated average concentration, based on the 3-leaves method, was ≤15% in approximately 65% of the cases compared to the measured concentration. This method could be used to calculate element concentrations and fluxes in phytomanagement, biomonitoring, or biomass productions projects using one-season poplar or willow cuttings. PMID:26691784

  6. Growth and molecular responses to long-distance stimuli in poplars: bending vs flame wounding.

    PubMed

    Tixier, Aude; Badel, Eric; Franchel, Jerome; Lakhal, Wassim; Leblanc-Fournier, Nathalie; Moulia, Bruno; Julien, Jean-Louis

    2014-02-01

    Inter-organ communication is essential for plants to coordinate development and acclimate to mechanical environmental fluctuations. The aim of this study was to investigate long-distance signaling in trees. We compared on young poplars the short-term effects of local flame wounding and of local stem bending for two distal responses: (1) stem primary growth and (2) the expression of mechanoresponsive genes in stem apices. We developed a non-contact measurement method based on the analysis of apex images in order to measure the primary growth of poplars. The results showed a phased stem elongation with alternating nocturnal circumnutation phases and diurnal growth arrest phases in Populus tremula × alba clone INRA 717-1B4. We applied real-time polymerase chain reaction (RT-PCR) amplifications in order to evaluate the PtaZFP2, PtaTCH2, PtaTCH4, PtaACS6 and PtaJAZ5 expressions. The flame wounding inhibited primary growth and triggered remote molecular responses. Flame wounding induced significant changes in stem elongation phases, coupled with inhibition of circumnutation. However, the circadian rhythm of phases remained unaltered and the treated plants were always phased with control plants during the days following the stress. For bent plants, the stimulated region of the stem showed an increased PtaJAZ5 expression, suggesting the jasmonates may be involved in local responses to bending. No significant remote responses to bending were observed. PMID:24032360

  7. Metabolic Flux Analysis of Plastidic Isoprenoid Biosynthesis in Poplar Leaves Emitting and Nonemitting Isoprene1[W

    PubMed Central

    Ghirardo, Andrea; Wright, Louwrance Peter; Bi, Zhen; Rosenkranz, Maaria; Pulido, Pablo; Rodríguez-Concepción, Manuel; Niinemets, Ülo; Brüggemann, Nicolas; Gershenzon, Jonathan; Schnitzler, Jörg-Peter

    2014-01-01

    The plastidic 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway is one of the most important pathways in plants and produces a large variety of essential isoprenoids. Its regulation, however, is still not well understood. Using the stable isotope 13C-labeling technique, we analyzed the carbon fluxes through the MEP pathway and into the major plastidic isoprenoid products in isoprene-emitting and transgenic isoprene-nonemitting (NE) gray poplar (Populus × canescens). We assessed the dependence on temperature, light intensity, and atmospheric [CO2]. Isoprene biosynthesis was by far (99%) the main carbon sink of MEP pathway intermediates in mature gray poplar leaves, and its production required severalfold higher carbon fluxes compared with NE leaves with almost zero isoprene emission. To compensate for the much lower demand for carbon, NE leaves drastically reduced the overall carbon flux within the MEP pathway. Feedback inhibition of 1-deoxy-d-xylulose-5-phosphate synthase activity by accumulated plastidic dimethylallyl diphosphate almost completely explained this reduction in carbon flux. Our data demonstrate that short-term biochemical feedback regulation of 1-deoxy-d-xylulose-5-phosphate synthase activity by plastidic dimethylallyl diphosphate is an important regulatory mechanism of the MEP pathway. Despite being relieved from the large carbon demand of isoprene biosynthesis, NE plants redirected only approximately 0.5% of this saved carbon toward essential nonvolatile isoprenoids, i.e. β-carotene and lutein, most probably to compensate for the absence of isoprene and its antioxidant properties. PMID:24590857

  8. Expression of the poplar Flowering Locus T1 (FT1) gene reduces the generation time in plum (Prunus domestica L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plums normally begin to flower and fruit three to seven years from seed. To shorten this generation time, early flowering plum genotypes were produced by transforming plum hypocotyls with the poplar (Populus trichocarpa) Flowering Locus T1 (PtFT1) gene. Ectopic expression of 35S::PtFT1 induced ear...

  9. Borehole geophysical data for the East Poplar oil field area, Fort Peck Indian Reservation, northeastern Montana, 1993, 2004, and 2005

    USGS Publications Warehouse

    Smith, Bruce D.; Thamke, Joanna N.; Tyrrell, Christa

    2014-01-01

    Areas of high electrical conductivity in shallow aquifers in the East Poplar oil field area were delineated by the U.S. Geological Survey (USGS), in cooperation with the Fort Peck Assiniboine and Sioux Tribes, in order to interpret areas of saline-water contamination. Ground, airborne, and borehole geophysical data were collected in the East Poplar oil field area from 1992 through 2005 as part of this delineation. This report presents borehole geophysical data for thirty-two wells that were collected during, 1993, 2004, and 2005 in the East Poplar oil field study area. Natural-gamma and induction instruments were used to provide information about the lithology and conductivity of the soil, rock, and water matrix adjacent to and within the wells. The well logs were also collected to provide subsurface controls for interpretation of a helicopter electromagnetic survey flown over most of the East Poplar oil field in 2004. The objective of the USGS studies was to improve understanding of aquifer hydrogeology particularly in regard to variations in water quality.

  10. Impact of an 8-Year-Old Transgenic Poplar Plantation on the Ectomycorrhizal Fungal Community ▿ †

    PubMed Central

    Stefani, Franck O. P.; Moncalvo, Jean-Marc; Séguin, Armand; Bérubé, Jean A.; Hamelin, Richard C.

    2009-01-01

    The long-term impact of field-deployed genetically modified trees on soil mutualistic organisms is not well known. This study aimed at evaluating the impact of poplars transformed with a binary vector containing the selectable nptII marker and β-glucuronidase reporter genes on ectomycorrhizal (EM) fungi 8 years after field deployment. We generated 2,229 fungal internal transcribed spacer (ITS) PCR products from 1,150 EM root tips and 1,079 fungal soil clones obtained from the organic and mineral soil horizons within the rhizosphere of three control and three transformed poplars. Fifty EM fungal operational taxonomic units were identified from the 1,706 EM fungal ITS amplicons retrieved. Rarefaction curves from both the root tips and soil clones were close to saturation, indicating that most of the EM species present were recovered. Based on qualitative and/or quantitative α- and β-diversity measurements, statistical analyses did not reveal significant differences between EM fungal communities associated with transformed poplars and the untransformed controls. However, EM communities recovered from the root tips and soil cloning analyses differed significantly from each other. We found no evidence of difference in the EM fungal community structure linked to the long-term presence of the transgenic poplars studied, and we showed that coupling root tip analysis with a soil DNA cloning strategy is a complementary approach to better document EM fungal diversity. PMID:19801471

  11. [Seasonal dynamics of quantitative and morphological traits of poplar fine roots and their differences between successive rotation plantations].

    PubMed

    Wang, Yan-ping; Xu, Tan; Zhu, Wan-rui; Wang, Qi-tong; Liu, Meng-ling; Wang, Hua-tian; Li, Chuan-rong; Dong, Yu-feng

    2016-02-01

    Based on the fine root samples of the first and second generations of poplar (Populus x euramericana ' Neva'), this study examined the response of quantitative and morphological traits of fine roots of different orders and the difference between generations. The results showed that, the quantitative traits of fine roots, such as root length, root surface area and root biomass, presented obvious seasonal variation, and the fine root traits had obvious difference among root orders. The quantitative traits of lower-order fine roots showed significant seasonal difference, and the fine root biomass increased in the growing season and then decreased significantly. The specific root length (SRL) of higher-order roots also showed significant change with season, while the root length density (RLD) and root tissue density (RTD) changed a little. The successive rotation resulted in the significant increase of root length, root biomass, SRL and RLD of 1-2 orders in the growing season. The quantitative traits of first order root significantly positively correlated with soil temperature and moisture, and significantly negatively correlated with the soil organic matter and soil available nitrogen content. However, the quantitative traits of second order root only showed significant correlation with soil nutrient content. The seasonal dynamics of poplar fine roots and the difference between successive rotation plantations implied carbon investment change of poplar to roots. Soil nutrient deficiency induced more carbon investment into roots, and this carbon allocation pattern might affect the aboveground productivity of poplar plantation. PMID:27396110

  12. Impact of poplar-based phytomanagement on soil properties and microbial communities in a metal-contaminated site.

    PubMed

    Foulon, Julie; Zappelini, Cyril; Durand, Alexis; Valot, Benoit; Blaudez, Damien; Chalot, Michel

    2016-10-01

    Despite a long history of use in phytomanagement strategies, the impacts of poplar trees on the structure and function of microbial communities that live in the soil remain largely unknown. The current study combined fungal and bacterial community analyses from different management regimes using Illumina-based sequencing with soil analysis. The poplar phytomanagement regimes led to a significant increase in soil fertility and a decreased bioavailability of Zn and Cd, in concert with changes in the microbial communities. The most notable changes in the relative abundance of taxa and operational taxonomic units unsurprisingly indicated that root and soil constitute distinct ecological microbial habitats, as exemplified by the dominance of Laccaria in root samples. The poplar cultivar was also an important driver, explaining 12% and 6% of the variance in the fungal and bacterial data sets, respectively. The overall dominance of saprophytic fungi, e.g. Penicillium canescens, might be related to the decomposition activities needed at the experimental site. Our data further highlighted that the mycorrhizal colonization of poplar cultivars varies greatly between the species and genotypes, which is exemplified by the dominance of Scleroderma under Vesten samples. Further interactions between fungal and bacterial functional groups stressed the potential of high-throughput sequencing technologies in uncovering the microbial ecology of disturbed environments. PMID:27481257

  13. The Poplar GT8E and GT8F Glycosyltransferases are Functional Orthologs of Arabidopsis PARVUS Involved in Gulcuronoxylan Biosynthesis

    EPA Science Inventory

    The poplar GT8E and GT8F glycosyltransferases have previously been shown to be associated with wood formation, but their roles in the biosynthesis of wood components are not known. Here, we show that PoGT8E and PoGT8F are expressed in vessels and fibers during wood formation and ...

  14. Identification of 4CL Genes in Desert Poplars and Their Changes in Expression in Response to Salt Stress

    PubMed Central

    Zhang, Cai-Hua; Ma, Tao; Luo, Wen-Chun; Xu, Jian-Mei; Liu, Jian-Quan; Wan, Dong-Shi

    2015-01-01

    4-Coumarate:CoA ligase (4CL) genes are critical for the biosynthesis of plant phenylpropanoids. Here we identified 20 4CL genes in the genomes of two desert poplars (Populus euphratica and P. pruinosa) and salt-sensitive congener (P. trichocarpa), but 12 in Salix suchowensis (Salix willow). Phylogenetic analyses clustered all Salicaceae 4CL genes into two clades, and one of them (corresponding to the 4CL-like clade from Arabidopsis) showed signals of adaptive evolution, with more genes retained in Populus than Salix and Arabidopsis. We also found that 4CL12 (in 4CL-like clade) showed positive selection along the two desert poplar lineages. Transcriptional profiling analyses indicated that the expression of 4CL2, 4CL11, and 4CL12 changed significantly in one or both desert poplars in response to salt stress compared to that of in P. trichocarpa. Our results suggest that the evolution of the 4CL genes may have contributed to the development of salt tolerance in the two desert poplars. PMID:26393655

  15. Patterns of genomic variation in the poplar rust fungus Melampsora larici-populina identify pathogenesis-related factors

    PubMed Central

    Persoons, Antoine; Morin, Emmanuelle; Delaruelle, Christine; Payen, Thibaut; Halkett, Fabien; Frey, Pascal; De Mita, Stéphane; Duplessis, Sébastien

    2014-01-01

    Melampsora larici-populina is a fungal pathogen responsible for foliar rust disease on poplar trees, which causes damage to forest plantations worldwide, particularly in Northern Europe. The reference genome of the isolate 98AG31 was previously sequenced using a whole genome shotgun strategy, revealing a large genome of 101 megabases containing 16,399 predicted genes, which included secreted protein genes representing poplar rust candidate effectors. In the present study, the genomes of 15 isolates collected over the past 20 years throughout the French territory, representing distinct virulence profiles, were characterized by massively parallel sequencing to assess genetic variation in the poplar rust fungus. Comparison to the reference genome revealed striking structural variations. Analysis of coverage and sequencing depth identified large missing regions between isolates related to the mating type loci. More than 611,824 single-nucleotide polymorphism (SNP) positions were uncovered overall, indicating a remarkable level of polymorphism. Based on the accumulation of non-synonymous substitutions in coding sequences and the relative frequencies of synonymous and non-synonymous polymorphisms (i.e., PN/PS), we identify candidate genes that may be involved in fungal pathogenesis. Correlation between non-synonymous SNPs in genes encoding secreted proteins (SPs) and pathotypes of the studied isolates revealed candidate genes potentially related to virulences 1, 6, and 8 of the poplar rust fungus. PMID:25309551

  16. Flare Hybrids

    NASA Astrophysics Data System (ADS)

    Tomczak, M.; Dubieniecki, P.

    2015-12-01

    On the basis of the Solar Maximum Mission observations, Švestka ( Solar Phys. 121, 399, 1989) introduced a new class of flares, the so-called flare hybrids. When they start, they look like typical compact flares (phase 1), but later on, they look like flares with arcades of magnetic loops (phase 2). We summarize the characteristic features of flare hybrids in soft and hard X-rays as well as in the extreme ultraviolet; these features allow us to distinguish flare hybrids from other flares. In this article, additional energy release or long plasma cooling timescales are suggested as possible causes of phase 2. We estimate the frequency of flare hybrids, and study the magnetic configurations favorable for flare hybrid occurrence. Flare hybrids appear to be quite frequent, and the difference between the lengths of magnetic loops in the two interacting loop systems seem to be a crucial parameter for determining their characteristics.

  17. Chemical characteristics and enzymatic saccharification of lignocellulosic biomass treated using high-temperature saturated steam: comparison of softwood and hardwood.

    PubMed

    Asada, Chikako; Sasaki, Chizuru; Hirano, Takeshi; Nakamura, Yoshitoshi

    2015-04-01

    This study investigated the effect of high-temperature saturated steam treatments on the chemical characteristics and enzymatic saccharification of softwood and hardwood. The weight loss and chemical modification of cedar and beech wood pieces treated at 25, 35, and 45 atm for 5 min were determined. Fourier transform infrared and X-ray diffraction analyses indicated that solubilization and removal of hemicellulose and lignin occurred by the steam treatment. The milling treatment of steam-treated wood enhanced its enzymatic saccharification. Maximum enzymatic saccharification (i.e., 94% saccharification rate of cellulose) was obtained using steam-treated beech at 35 atm for 5 min followed by milling treatment for 1 min. However, the necessity of the milling treatment for efficient enzymatic saccharification is dependent on the wood species. PMID:25704097

  18. Comparison of lab, pilot, and industrial scale low consistency mechanical refining for improvements in enzymatic digestibility of pretreated hardwood.

    PubMed

    Jones, Brandon W; Venditti, Richard; Park, Sunkyu; Jameel, Hasan

    2014-09-01

    Mechanical refining has been shown to improve biomass enzymatic digestibility. In this study industrial high-yield sodium carbonate hardwood pulp was subjected to lab, pilot and industrial refining to determine if the mechanical refining improves the enzymatic hydrolysis sugar conversion efficiency differently at different refining scales. Lab, pilot and industrial refining increased the biomass digestibility for lignocellulosic biomass relative to the unrefined material. The sugar conversion was increased from 36% to 65% at 5 FPU/g of biomass with industrial refining at 67.0 kWh/t, which was more energy efficient than lab and pilot scale refining. There is a maximum in the sugar conversion with respect to the amount of refining energy. Water retention value is a good predictor of improvements in sugar conversion for a given fiber source and composition. Improvements in biomass digestibility with refining due to lab, pilot plant and industrial refining were similar with respect to water retention value. PMID:25016156

  19. Comparing regeneration techniques for afforesting previously farmed bottomland hardwood sites in the Lower Mississippi Alluvial Valley, USA

    USGS Publications Warehouse

    Lockhart, B.R.; Keeland, B.; McCoy, J.; Dean, T.J.

    2003-01-01

    A study was implemented to test site preparation methods and artificial regeneration of three oak (Quercus spp.) species on four agricultural fields in the Lower Mississippi Alluvial Valley in Louisiana, USA. Six years after establishment, few consistent differences were found in oak density between sowing acorn methods (seed drill versus broadcast seeding), autumn sowing versus spring sowing, and sowing acorns versus planting oak seedlings. Results indicated that some degree of site preparation is needed to establish oak seedlings but few differences were found between site preparation treatments. These results indicate that no one prescription for oak regeneration fits all potential afforestation projects in the Lower Mississippi Alluvial Valley. Successful bottomland hardwood afforestation projects will require plans that include specific objectives, site evaluation, and a regeneration prescription prior to sowing the first seed or planting the first seedling.

  20. Effects of crown position and initial spacing on foliar nutrient composition of seven bottomland hardwoods. Forest Service research note

    SciTech Connect

    Kennedy, H.E.

    1993-01-01

    Seven plantation-grown bottomland hardwoods, sweetgum (Liquidambar stryaciflua L.), green ash (Fraxinus pennsylvanica Marsh.), American sycamore (Platanus occidentalis L.), water oak (Quercus nigra L.), Nuttall oak (Q. nuttallii Palmer), cherrybark oak (Q. falcata var. pagodifolia Ell.), and swamp chestnut oak (Q. michauxii Nutt.), were sampled after the seventh growing season to determine foliar nutrient concentrations. Foliage samples were collected from the upper, middle, and lower crown positions and from the entire crown. Determinations were made for levels of nitrogen, phosphorus, potassium, calcium, and magnesium. Spacing had no effect on nutrient concentrations. Nutrient levels differed by crown position for some nutrients in most species. Most of the differences were in the nitrogen, calcium, and magnesium levels.

  1. Effects of aerially applied glyphosate and hexazinone on hardwoods and pines in a loblolly pine plantation. Forest Service research paper

    SciTech Connect

    Haywood, J.D.

    1993-09-01

    Areas in a 4-year-old loblolly pine (Pinus taeda L.) plantation were treated with aerially applied Roundup (glyphosate), Pronone 10G (hexazinone), and Velpar L (hexazinone) plus Lo Drift (a spray additive). All herbicides were applied with appropriate helicopter-mounted equipment. The proportion of free-to-grow pine trees increased over a 2-year period in both the treated and untreated areas, but the increase was slightly greater in the treated areas. Final loblolly pine height, d.b.h., and volume per tree did not differ significantly among the four treatments. About 1,200 hardwood trees and 4,700 shrubs over 3 ft tall per acre were present at the beginning of the study.

  2. A Comparison of the Effects of Clearcutting Hardwood Forests on Nitrate Movement in 3 Watersheds in Northeastern North America

    NASA Astrophysics Data System (ADS)

    Murdoch, P. S.; Beall, F. D.; Burns, D. A.

    2001-12-01

    Experimental harvests of forested watersheds have occurred in several locations throughout the United States and Canada to assess the effects of clearcutting on forest regeneration and runoff water quality. A comparison of the effects of harvesting on stream water quality at three of these watersheds --Watershed 5 at the Hubbard Brook Experimental Forest in New Hampshire (22 hectares logged during the fall 1983-winter 1984), Dry Creek in the Catskill Mountains of New York (22 hectares logged during winter, 1997), and Watershed 31 at the Turkey Lakes Watershed in western Ontario (4.62 hectares logged during late summer, 1997) indicates similarities in stream chemical response despite large differences in year of harvest, pre-harvest water quality, and geographic location. All three watersheds in the comparison contain Northern Hardwood forests. The magnitude, duration, and seasonal variability in stream nitrate concentrations following harvest were similar among the 3 watersheds studied. Harvesting during August at Turkey Lakes caused a 100 uEq/L increase in nitrate concentrations during the immediate fall, but peak nitrate concentrations in streamwater were delayed to the late summer of the following year. Watershed 5 and Dry Creek had peak nitrate concentrations in the late summer and fall of the first year following harvest. The period of recovery from peak nitrate concentration to pre-cut concentrations was similar among the sites. The summer logging at Turkey Lakes thus had the effect of lengthening the period of elevated stream nitrate concentrations relative to the winter logging operations of the other two harvests. Trends in dissolved organic carbon and ammonium were not significantly affected by the logging in comparison with the effect on nitrate concentrations, and ammonium was a minor contributor to the nitrogen yield from the watersheds. The comparison indicates a general pattern of nitrogen release following clearcutting of hardwood forests in

  3. Subfossil leaves reveal a new upland hardwood component of the pre-European Piedmont landscape,Lancaster County, Pennsylvania.

    PubMed

    Elliott, Sara J; Wilf, Peter; Walter, Robert C; Merritts, Dorothy J

    2013-01-01

    Widespread deforestation, agriculture, and construction of milldams by European settlers greatly influenced valley-bottom stream morphology and riparian vegetation in the northeastern USA. The former broad, tussock-sedge wetlands with small, anastomosing channels were converted into today's incised, meandering streams with unstable banks that support mostly weedy, invasive vegetation. Vast accumulations of fine-grained "legacy" sediments that blanket the regional valley-bottom Piedmont landscape now are being reworked from stream banks, significantly impairing the ecological health of downstream water bodies, most notably the Chesapeake Bay. However, potential restoration is impaired by lack of direct knowledge of the pre-settlement riparian and upslope floral ecosystems. We studied the subfossil leaf flora of Denlingers Mill, an obsolete (breached) milldam site in southeastern Pennsylvania that exhibits a modern secondary forest growing atop thin soils, above bedrock outcrops immediately adjacent to a modified, incised stream channel. Presumably, an overhanging old-growth forest also existed on this substrate until the early 1700s and was responsible for depositing exceptionally preserved, minimally transported subfossil leaves into hydric soil strata, which immediately underlie post-European settlement legacy sediments. We interpret the eleven identified species of the subfossil assemblage to primarily represent a previously unknown, upland Red Oak-American Beech mixed hardwood forest. Some elements also appear to belong to a valley-margin Red Maple-Black Ash swamp forest, consistent with preliminary data from a nearby site. Thus, our results add significantly to a more complete understanding of the pre-European settlement landscape, especially of the hardwood tree flora. Compared with the modern forest, it is apparent that both lowland and upslope forests in the region have been modified significantly by historical activities. Our study underscores that

  4. Subfossil Leaves Reveal a New Upland Hardwood Component of the Pre-European Piedmont Landscape, Lancaster County, Pennsylvania

    PubMed Central

    Elliott, Sara J.; Wilf, Peter; Walter, Robert C.; Merritts, Dorothy J.

    2013-01-01

    Widespread deforestation, agriculture, and construction of milldams by European settlers greatly influenced valley-bottom stream morphology and riparian vegetation in the northeastern USA. The former broad, tussock-sedge wetlands with small, anastomosing channels were converted into today’s incised, meandering streams with unstable banks that support mostly weedy, invasive vegetation. Vast accumulations of fine-grained “legacy” sediments that blanket the regional valley-bottom Piedmont landscape now are being reworked from stream banks, significantly impairing the ecological health of downstream water bodies, most notably the Chesapeake Bay. However, potential restoration is impaired by lack of direct knowledge of the pre-settlement riparian and upslope floral ecosystems. We studied the subfossil leaf flora of Denlingers Mill, an obsolete (breached) milldam site in southeastern Pennsylvania that exhibits a modern secondary forest growing atop thin soils, above bedrock outcrops immediately adjacent to a modified, incised stream channel. Presumably, an overhanging old-growth forest also existed on this substrate until the early 1700s and was responsible for depositing exceptionally preserved, minimally transported subfossil leaves into hydric soil strata, which immediately underlie post-European settlement legacy sediments. We interpret the eleven identified species of the subfossil assemblage to primarily represent a previously unknown, upland Red Oak-American Beech mixed hardwood forest. Some elements also appear to belong to a valley-margin Red Maple-Black Ash swamp forest, consistent with preliminary data from a nearby site. Thus, our results add significantly to a more complete understanding of the pre-European settlement landscape, especially of the hardwood tree flora. Compared with the modern forest, it is apparent that both lowland and upslope forests in the region have been modified significantly by historical activities. Our study underscores that

  5. Gain-of-function analysis of poplar CLE genes in Arabidopsis by exogenous application and over-expression assays.

    PubMed

    Liu, Yisen; Yang, Shaohui; Song, Yingjin; Men, Shuzhen; Wang, Jiehua

    2016-04-01

    Among 50CLEgene family members in thePopulus trichocarpagenome, three and sixPtCLEgenes encode a CLE motif sequence highly homologous toArabidopsisCLV3 and TDIF peptides, respectively, which potentially make them functional equivalents. To test and compare their biological activity, we first chemically synthesized each dodecapeptide and analysed itsin vitrobioactivity on Arabidopsis seedlings. Similarly, but to a different extent, three types of poplar CLV3-related peptides caused root meristem consumption, phyllotaxis disorder, anthocyanin accumulation and failure to enter the bolting stage. In comparison, application of two poplar TDIF-related peptides led to root length promotion in a dose-dependent manner with an even stronger effect observed for poplar TDIF-like peptide than TDIF. Next, we constructedCaMV35S:PtCLEtransgenic plants for each of the ninePtCLEgenes. Phenotypic abnormalities exemplified by arrested shoot apical meristem and abnormal flower structure were found to be more dominant and severe in35S:PtCLV3and35S:PtCLV3-like2lines than in the35S:PtCLV3-like1line. Disordered vasculature was detected in both stem and hypocotyl cross-sections in Arabidopsis plants over-expressing poplarTDIF-relatedgenes with the most defective vascular patterning observed forTDIF2and twoTDIF-likegenes. Phenotypic difference consistently observed in peptide application assay and transgenic analysis indicated the functional diversity of nine poplarPtCLEgenes under investigation. This work represents the first report on the functional analysis ofCLEgenes in a tree species and constitutes a basis for further study of the CLE peptide signalling pathway in tree development. PMID:26912800

  6. Matching the Best Viewing Angle in Depth Cameras for Biomass Estimation Based on Poplar Seedling Geometry

    PubMed Central

    Andújar, Dionisio; Fernández-Quintanilla, César; Dorado, José

    2015-01-01

    In energy crops for biomass production a proper plant structure is important to optimize wood yields. A precise crop characterization in early stages may contribute to the choice of proper cropping techniques. This study assesses the potential of the Microsoft Kinect for Windows v.1 sensor to determine the best viewing angle of the sensor to estimate the plant biomass based on poplar seedling geometry. Kinect Fusion algorithms were used to generate a 3D point cloud from the depth video stream. The sensor was mounted in different positions facing the tree in order to obtain depth (RGB-D) images from different angles. Individuals of two different ages, e.g., one month and one year old, were scanned. Four different viewing angles were compared: top view (0°), 45° downwards view, front view (90°) and ground upwards view (−45°). The ground-truth used to validate the sensor readings consisted of a destructive sampling in which the height, leaf area and biomass (dry weight basis) were measured in each individual plant. The depth image models agreed well with 45°, 90° and −45° measurements in one-year poplar trees. Good correlations (0.88 to 0.92) between dry biomass and the area measured with the Kinect were found. In addition, plant height was accurately estimated with a few centimeters error. The comparison between different viewing angles revealed that top views showed poorer results due to the fact the top leaves occluded the rest of the tree. However, the other views led to good results. Conversely, small poplars showed better correlations with actual parameters from the top view (0°). Therefore, although the Microsoft Kinect for Windows v.1 sensor provides good opportunities for biomass estimation, the viewing angle must be chosen taking into account the developmental stage of the crop and the desired parameters. The results of this study indicate that Kinect is a promising tool for a rapid canopy characterization, i.e., for estimating crop biomass

  7. Matching the best viewing angle in depth cameras for biomass estimation based on poplar seedling geometry.

    PubMed

    Andújar, Dionisio; Fernández-Quintanilla, César; Dorado, José

    2015-01-01

    In energy crops for biomass production a proper plant structure is important to optimize wood yields. A precise crop characterization in early stages may contribute to the choice of proper cropping techniques. This study assesses the potential of the Microsoft Kinect for Windows v.1 sensor to determine the best viewing angle of the sensor to estimate the plant biomass based on poplar seedling geometry. Kinect Fusion algorithms were used to generate a 3D point cloud from the depth video stream. The sensor was mounted in different positions facing the tree in order to obtain depth (RGB-D) images from different angles. Individuals of two different ages, e.g., one month and one year old, were scanned. Four different viewing angles were compared: top view (0°), 45° downwards view, front view (90°) and ground upwards view (-45°). The ground-truth used to validate the sensor readings consisted of a destructive sampling in which the height, leaf area and biomass (dry weight basis) were measured in each individual plant. The depth image models agreed well with 45°, 90° and -45° measurements in one-year poplar trees. Good correlations (0.88 to 0.92) between dry biomass and the area measured with the Kinect were found. In addition, plant height was accurately estimated with a few centimeters error. The comparison between different viewing angles revealed that top views showed poorer results due to the fact the top leaves occluded the rest of the tree. However, the other views led to good results. Conversely, small poplars showed better correlations with actual parameters from the top view (0°). Therefore, although the Microsoft Kinect for Windows v.1 sensor provides good opportunities for biomass estimation, the viewing angle must be chosen taking into account the developmental stage of the crop and the desired parameters. The results of this study indicate that Kinect is a promising tool for a rapid canopy characterization, i.e., for estimating crop biomass

  8. Final report from VFL technologies for the pilot-scale thermal treatment of Lower East Fork Poplar Creek floodplain soils: LEFPC appendices, volume 1, appendix I-IV

    SciTech Connect

    1994-09-01

    This document contains Appendix I-IV for the pilot-scale thermal treatment of lower East Fork Poplar Creek floodplain soils. Included are calibration records; quality assurance; soils characterization; pilot scale trial runs.

  9. Final report from VFL Technologies for the pilot-scale thermal treatment of lower East Fork Poplar Creek floodplain soils. LEFPC appendices, Volume 4, Appendix V-C

    SciTech Connect

    1994-09-01

    This is the the final verification run data package for pilot scale thermal treatment of lower East Fork Poplar Creek floodplain soils. Included are data on volatiles, semivolatiles, and TCLP volatiles.

  10. Results of a workshop concerning assessment of the functions of bottomland hardwoods

    USGS Publications Warehouse

    Roelle, James E.; Auble, Gregor T.; Hamilton, David B.; Johnson, Richard L.; Segelquist, Charles A.

    1987-01-01

    Recognizing the importance of implementing an effective, nationally consistent, and scientifically defensible regulatory program, EPA, in October 1984, issued Interim Operating Guidance to its field personnel for implementing the Section 404 regulatory program in bottomland hardwood wetlands. With the goal of improving and finalizing that guidance, EPA is sponsoring a series of workshops designed to answer key questions concerning BLH wetlands, based on the best scientific and technical information currently available. The first two workshops were directed toward summarizing existing scientific and technical knowledge concerning the functions of BLH ecosystems, the characteristics that are important to each function, and the impact of various development activities on those characteristics. The first workshop, which was held in St. Francisville, Louisiana, in December, 1984, examined a wetland zonation concept as a framework for gaining a greater understanding of BLH structure and function. The workshop set out to determine whether characterization of BLH resources as a series of relatively distinct zones, defined by concomitant variation in hydrologic regime, soils, and vegetation, might provide the basis for a useful and scientifically sound regulatory framework. For examp1e, if certain zones are of particular importance to one or more wetland functions that the Clean Water Act was intended to protect, then the zonation concept might be useful from the perspective of how various activities should be regulated. Discussions during the first workshop, however, indicated that the zonation concept provides, at best, only an incomplete picture of the structure and function of BLH ecosystems. In many cases, BLH functions are not limited to or closely correlated with particular zones and, furthermore, many factors other than zone are important determinants of BLH functions. With these responses in mind, the second workshop, held at Lake Lanier, Georgia, in July, 1985

  11. Steam gasification of tyre waste, poplar, and refuse-derived fuel: a comparative analysis.

    PubMed

    Galvagno, S; Casciaro, G; Casu, S; Martino, M; Mingazzini, C; Russo, A; Portofino, S

    2009-02-01

    In the field of waste management, thermal disposal is a treatment option able to recover resources from "end of life" products. Pyrolysis and gasification are emerging thermal treatments that work under less drastic conditions in comparison with classic direct combustion, providing for reduced gaseous emissions of heavy metals. Moreover, they allow better recovery efficiency since the process by-products can be used as fuels (gas, oils), for both conventional (classic engines and heaters) and high efficiency apparatus (gas turbines and fuel cells), or alternatively as chemical sources or as raw materials for other processes. This paper presents a comparative study of a steam gasification process applied to three different waste types (refuse-derived fuel, poplar wood and scrap tyres), with the aim of comparing the corresponding yields and product compositions and exploring the most valuable uses of the by-products. PMID:18657408

  12. An integrated detoxification process with electrodialysis and adsorption from the hemicellulose hydrolysates of yellow poplars.

    PubMed

    Trinh, Ly Thi Phi; Kundu, Chandan; Lee, Jae-Won; Lee, Hong-Joo

    2014-06-01

    An integrated detoxification process with electrodialysis (ED) followed by adsorption was performed to remove fermentation inhibitors from hemicellulose hydrolysates. The hydrolysates were prepared by oxalic acid pretreatment of yellow poplars at different temperatures. Of fermentation inhibitors, acetic acid showed high removal efficiency of about 90% and high transport rate during the ED process without membrane fouling. The integration of the detoxification processes increased up to the ethanol yield of 0.33g/g sugar, the ethanol production of about 9g/L, and the productivity of 0.12g/Lh, while the fermentation of non-detoxified hydrolysates did not produce bioethanol. The influence of inhibitor concentration on the fermentability showed that HMF had the highest inhibition effect. The results clearly showed that an integrated detoxification process with ED followed by adsorption removed fermentation inhibitors with high efficiency and increased the fermentability of the oxalic acid pretreated hemicellulose hydrolysates. PMID:24713602

  13. Beetle feeding induces a different volatile emission pattern from black poplar foliage than caterpillar herbivory.

    PubMed

    Unsicker, Sybille B; Gershenzon, Jonathan; Köllner, Tobias G

    2015-01-01

    Herbivore-induced plant volatile emission is often considered to be attacker species-specific, but most experimental evidence comes from short lived herbaceous species. In a recent study we showed that black poplar (Populus nigra) trees emit a complex blend of volatiles from damaged leaves when they are attacked by generalist gypsy moth (Lymantria dispar) caterpillars. Minor nitrogenous volatiles were especially characteristic of this blend. Here we show that attack on P. nigra by a beetle species, Phratora vulgatissima (Coleoptera, Chrysomelidae), led to the emission of the same compounds as already observed after caterpillar herbivory, but with striking quantitative changes in the blend. The consequences for attraction of herbivore enemies are discussed. PMID:25831045

  14. Environmental controls on ozone fluxes in a poplar plantation in Western Europe.

    PubMed

    Zona, D; Gioli, B; Fares, S; De Groote, T; Pilegaard, K; Ibrom, A; Ceulemans, R

    2014-01-01

    Tropospheric O3 is a strong oxidant that may affect vegetation and human health. Here we report on the O3 fluxes from a poplar plantation in Belgium during one year. Surprisingly, the winter and autumn O3 fluxes were of similar magnitude to ones observed during most of the peak vegetation development. Largest O3 uptakes were recorded at the beginning of the growing season in correspondence to a minimum stomatal uptake. Wind speed was the most important control and explained 44% of the variability in the nighttime O3 fluxes, suggesting that turbulent mixing and the mechanical destruction of O3 played a substantial role in the O3 fluxes. The stomatal O3 uptake accounted for a seasonal average of 59% of the total O3 uptake. Multiple regression and partial correlation analyses showed that net ecosystem exchange was not affected by the stomatal O3 uptake. PMID:24060739

  15. Beetle feeding induces a different volatile emission pattern from black poplar foliage than caterpillar herbivory

    PubMed Central

    Unsicker, Sybille B.; Gershenzon, Jonathan; Köllner, Tobias G.

    2015-01-01

    Herbivore-induced plant volatile emission is often considered to be attacker species-specific, but most experimental evidence comes from short lived herbaceous species. In a recent study we showed that black poplar (Populus nigra) trees emit a complex blend of volatiles from damaged leaves when they are attacked by generalist gypsy moth (Lymantria dispar) caterpillars. Minor nitrogenous volatiles were especially characteristic of this blend. Here we show that attack on P. nigra by a beetle species, Phratora vulgatissima (Coleoptera, Chrysomelidae), led to the emission of the same compounds as already observed after caterpillar herbivory, but with striking quantitative changes in the blend. The consequences for attraction of herbivore enemies are discussed. PMID:25831045

  16. Assisted phytoremediation of Cd-contaminated soil using poplar rooted cuttings

    NASA Astrophysics Data System (ADS)

    Alizadeh, S.; Zahedi-Amiri, G.; Savaghebi-Firoozabadi, G.; Etemad, V.; Shirvany, A.; Shirmardi, M.

    2012-07-01

    To investigate the effect of amended substrates on cadmium uptake by one-year old poplar rooted cuttings a pot culture was carried out. Pots were filled with three substrates. Four treatments of Cd supply including were organized. The results showed that higher biomass productions in substrates A and B compare to substrate C, led to an increase total Cd uptake two times more than that in substrate C, at 150 mg kg-1 concentration. Meanwhile maximum total uptake occurred in substrate B at 100 mg kg-1 concentration. Using synthetic chelators such as ethylenediaminetetraacetic acid in order to achieve high removal rate led to increased environmental impacts while they are not expected when such environmental friendly approaches are applied.

  17. Robustness of two-step acid hydrolysis procedure for composition analysis of poplar.

    PubMed

    Bhagia, Samarthya; Nunez, Angelica; Wyman, Charles E; Kumar, Rajeev

    2016-09-01

    The NREL standard procedure for lignocellulosic biomass composition has two steps: primary hydrolysis in 72% wt sulfuric acid at 30°C for 1h followed by secondary hydrolysis of the slurry in 4wt% acid at 121°C for 1h. Although pointed out in the NREL procedure, the impact of particle size on composition has never been shown. In addition, the effects of primary hydrolysis time and separation of solids prior to secondary hydrolysis on composition have never been shown. Using poplar, it was found that particle sizes less than 0.250mm significantly lowered the glucan content and increased the Klason lignin but did not affect xylan, acetate, or acid soluble lignin contents. Composition was unaffected for primary hydrolysis time between 30 and 90min. Moreover, separating solids prior to secondary hydrolysis had negligible effect on composition suggesting that lignin and polysaccharides are completely separated in the primary hydrolysis stage. PMID:27282557

  18. Use of active extracts of poplar buds against Penicillium italicum and possible modes of action.

    PubMed

    Yang, Shuzhen; Liu, Limei; Li, Dongmei; Xia, Huan; Su, Xiaojun; Peng, Litao; Pan, Siyi

    2016-04-01

    Antifungal components, from poplar buds active fraction (PBAF) against Penicillium italicum, the causal agent of blue mold in citrus fruits, were identified and possible action modes were investigated. Pinocembrin, chrysin and galangin were determined as active components in PBAF, using HPLC and HPLC-MS analysis. The antifungal activity is stable at temperatures ranging from 4 °C to 100 °C and pH levels ranging from 4 to 8. In the presence of PBAF, the hyphae become shriveled, wrinkled and the cell membrane became seriously disrupted. Further investigation on cell permeability, nucleic acid content and alkaline phosphatase suggest that the cell membrane might be the target. Mycelial oxygen consumption and the respiration-related enzymatic activity of succinate dehydrogenase, malate dehydrogenase and ATPase were all inhibited by PBAF. We propose that PBAF is a potentially useful alternative for blue mold control and may act against P. italicum by interfering with respiration and disrupting the cell membrane. PMID:26593534

  19. Steam gasification of tyre waste, poplar, and refuse-derived fuel: A comparative analysis

    SciTech Connect

    Galvagno, S. Casciaro, G.; Casu, S.; Martino, M.; Mingazzini, C.; Russo, A.; Portofino, S.

    2009-02-15

    In the field of waste management, thermal disposal is a treatment option able to recover resources from 'end of life' products. Pyrolysis and gasification are emerging thermal treatments that work under less drastic conditions in comparison with classic direct combustion, providing for reduced gaseous emissions of heavy metals. Moreover, they allow better recovery efficiency since the process by-products can be used as fuels (gas, oils), for both conventional (classic engines and heaters) and high efficiency apparatus (gas turbines and fuel cells), or alternatively as chemical sources or as raw materials for other processes. This paper presents a comparative study of a steam gasification process applied to three different waste types (refuse-derived fuel, poplar wood and scrap tyres), with the aim of comparing the corresponding yields and product compositions and exploring the most valuable uses of the by-products.

  20. Genetic variation among lake states balsam poplar populations is associated with geographic origin

    SciTech Connect

    Riemenschneider, D.E.; McMahon, B.G. )

    1993-02-01

    Variation among populations of balsam poplar from Minnesota, Wisconsin, and Michigan (the Lake States) in tree height, phenology, and sylleptic branching was associated with geographic origin based on bivariate correlation, canonical correlation, principal component, and cluster analyses. Ninety percent of the joint variation in five traits was explained by two principal components, the first associated with late season growth and tree height, the second associated with number of sylleptic branches. Populations were delineated into northwestern, central, and southeastern clusters based on principal component one and two coordinates using Ward's minimum variance method. Populations from the southeastern cluster grew taller, produced more late season leaves, and set bud later than populations from the northwestern and central clusters. 11 refs., 1 fig., 3 tabs.

  1. A study of poplar organosolv lignin after melt rheology treatment as carbon fiber precursors

    DOE PAGESBeta

    Sun, Qining; Khunsupat, Ratayakorn; Akato, Kokouvi; Tao, Jingming; Labbe, Nicole; Gallego, Nidia C.; Bozell, Joseph J.; Rials, Timothy G.; Tuskan, Gerald A.; Tschaplinski, Timothy J.; et al

    2016-06-16

    Lignins from various poplar genotypes were isolated by using organosolv fractionation and subjected to rheological treatment at various temperatures. Physicochemical characterization of the lignin variants shows a broad distribution of glass transition temperatures, melt viscosity, and pyrolysis char residues. Rheological treatment at 170 °C induces lignin repolymerization accompanied with an increase in condensed linkages, molecular weights, and viscosities. In contrast, rheology testing at 190 °C results in the decrease in lignin aliphatic and phenolic hydroxyl groups, β-O-aryl ether linkages, molecular weights, and viscosity values. Lignin under air cooling generates more oxygenated and condensed compounds, but lower amounts of ether linkagesmore » than lignin cooled under nitrogen. Here, lignin with a lower syringyl/guaiacyl ratio tends to form more cross-linkages along with higher viscosity values, higher molecular weight and larger amounts of condensed bonds.« less

  2. Ecological risk assessment of aerial insectivores of the Clinch River/Poplar Creek system

    SciTech Connect

    Baron, L.A.; Sample, B.E.

    1995-12-31

    Risks to aerial insectivores (species that consume flying insects; rough-winged swallows, little brown bats, and endangered gray bats) were assessed for the CERCLA remedial investigation of the Clinch River/Poplar Creek system. Adult mayflies and sediment were collected from four locations and analyzed for contaminants. Sediment-to-mayfly contaminant transfer factors were generated from these data and used to estimate contaminant concentrations in mayflies from thirteen additional locations. Contaminants of potential concern (COPCs) were identified by comparing exposure estimates, generated using point estimates of parameter values, to NOAELS. COPCs included mercury, arsenic, and PCBs. Exposure to COPCs was re-estimated using Monte Carlo simulations. Adverse population effects were assumed likely if > 20% of the estimated exposure distribution was greater than the LOAEL. Exposure of swallows to mercury was a significant risk at two locations. Exposure of bats to mercury was a significant risk at only one location. While consideration of movement and foraging territory did not reduce estimated risks to swallows, when exposures for gray and little brown bats were re-estimated, population-level risks from mercury were no longer considered likely. As an endangered species however, protection is extended to individual gray bats. While less than 20% of the mercury exposure distribution for gray bats was > LOAEL, > 99% of the distribution was >NOAEL. Therefore, adverse effects may occur among maximally exposed individual gray bats. Available data indicate that contaminants in Poplar Creek are likely to present a risk to the swallow population, do not present a risk to the little brown bat population, and may present a risk to individual gray bats.

  3. Moderate salt treatment alleviates ultraviolet-B radiation caused impairment in poplar plants

    PubMed Central

    Ma, Xuan; Ou, Yong-Bin; Gao, Yong-Feng; Lutts, Stanley; Li, Tao-Tao; Wang, Yang; Chen, Yong-Fu; Sun, Yu-Fang; Yao, Yin-An

    2016-01-01

    The effects of moderate salinity on the responses of woody plants to UV-B radiation were investigated using two Populus species (Populus alba and Populus russkii). Under UV-B radiation, moderate salinity reduced the oxidation pressure in both species, as indicated by lower levels of cellular H2O2 and membrane peroxidation, and weakened the inhibition of photochemical efficiency expressed by O-J-I-P changes. UV-B-induced DNA lesions in chloroplast and nucleus were alleviated by salinity, which could be explained by the higher expression levels of DNA repair system genes under UV-B&salt condition, such as the PHR, DDB2, and MutSα genes. The salt-induced increase in organic osmolytes proline and glycine betaine, afforded more efficient protection against UV-B radiation. Therefore moderate salinity induced cross-tolerance to UV-B stress in poplar plants. It is thus suggested that woody plants growing in moderate salted condition would be less affected by enhanced UV-B radiation than plants growing in the absence of salt. Our results also showed that UV-B signal genes in poplar plants PaCOP1, PaSTO and PaSTH2 were quickly responding to UV-B radiation, but not to salt. The transcripts of PaHY5 and its downstream pathway genes (PaCHS1, PaCHS4, PaFLS1 and PaFLS2) were differently up-regulated by these treatments, but the flavonoid compounds were not involved in the cross-tolerance since their concentration increased to the same extent in both UV-B and combined stresses. PMID:27597726

  4. S-Nitroso-Proteome in Poplar Leaves in Response to Acute Ozone Stress

    PubMed Central

    Vanzo, Elisa; Ghirardo, Andrea; Merl-Pham, Juliane; Lindermayr, Christian; Heller, Werner; Hauck, Stefanie M.; Durner, Jörg; Schnitzler, Jörg-Peter

    2014-01-01

    Protein S-nitrosylation, the covalent binding of nitric oxide (NO) to protein cysteine residues, is one of the main mechanisms of NO signaling in plant and animal cells. Using a combination of the biotin switch assay and label-free LC-MS/MS analysis, we revealed the S-nitroso-proteome of the woody model plant Populus x canescens. Under normal conditions, constitutively S-nitrosylated proteins in poplar leaves and calli comprise all aspects of primary and secondary metabolism. Acute ozone fumigation was applied to elicit ROS-mediated changes of the S-nitroso-proteome. This treatment changed the total nitrite and nitrosothiol contents of poplar leaves and affected the homeostasis of 32 S-nitrosylated proteins. Multivariate data analysis revealed that ozone exposure negatively affected the S-nitrosylation status of leaf proteins: 23 proteins were de-nitrosylated and 9 proteins had increased S-nitrosylation content compared to the control. Phenylalanine ammonia-lyase 2 (log2[ozone/control] = −3.6) and caffeic acid O-methyltransferase (−3.4), key enzymes catalyzing important steps in the phenylpropanoid and subsequent lignin biosynthetic pathways, respectively, were de-nitrosylated upon ozone stress. Measuring the in vivo and in vitro phenylalanine ammonia-lyase activity indicated that the increase of the phenylalanine ammonia-lyase activity in response to acute ozone is partly regulated by de-nitrosylation, which might favor a higher metabolic flux through the phenylpropanoid pathway within minutes after ozone exposure. PMID:25192423

  5. The poplar Phi class glutathione transferase: expression, activity and structure of GSTF1

    PubMed Central

    Pégeot, Henri; Koh, Cha San; Petre, Benjamin; Mathiot, Sandrine; Duplessis, Sébastien; Hecker, Arnaud; Didierjean, Claude; Rouhier, Nicolas

    2014-01-01

    Glutathione transferases (GSTs) constitute a superfamily of enzymes with essential roles in cellular detoxification and secondary metabolism in plants as in other organisms. Several plant GSTs, including those of the Phi class (GSTFs), require a conserved catalytic serine residue to perform glutathione (GSH)-conjugation reactions. Genomic analyses revealed that terrestrial plants have around ten GSTFs, eight in the Populus trichocarpa genome, but their physiological functions and substrates are mostly unknown. Transcript expression analyses showed a predominant expression of all genes both in reproductive (female flowers, fruits, floral buds) and vegetative organs (leaves, petioles). Here, we show that the recombinant poplar GSTF1 (PttGSTF1) possesses peroxidase activity toward cumene hydroperoxide and GSH-conjugation activity toward model substrates such as 2,4-dinitrochlorobenzene, benzyl and phenetyl isothiocyanate, 4-nitrophenyl butyrate and 4-hydroxy-2-nonenal but interestingly not on previously identified GSTF-class substrates. In accordance with analytical gel filtration data, crystal structure of PttGSTF1 showed a canonical dimeric organization with bound GSH or 2-(N-morpholino)ethanesulfonic acid molecules. The structure of these protein-substrate complexes allowed delineating the residues contributing to both the G and H sites that form the active site cavity. In sum, the presence of GSTF1 transcripts and proteins in most poplar organs especially those rich in secondary metabolites such as flowers and fruits, together with its GSH-conjugation activity and its documented stress-responsive expression suggest that its function is associated with the catalytic transformation of metabolites and/or peroxide removal rather than with ligandin properties as previously reported for other GSTFs. PMID:25566286

  6. Long lasting effects of the conversion from natural forest to poplar plantation on soil microbial communities.

    PubMed

    Vitali, Francesco; Mastromei, Giorgio; Senatore, Giuliana; Caroppo, Cesarea; Casalone, Enrico

    2016-01-01

    In this study, we evaluate the long-lasting effects on soil microbial communities of a change within a single land-use category, specifically the conversion from natural forest to forest plantation. To minimize the effects of impacts other than land-use (i.e., climatic and anthropogenic), we chose three sites within a Natural Park, with homogeneous orographic and soil texture characteristics. We compared microbial diversity in a total of 156 soil samples from two natural mixed forests and a similar forest converted to poplar plantation about thirty years ago. The diversity and structure of bacterial and fungal communities were investigated by terminal restriction fragments length polymorphism (T-RFLP) analysis of the 16S-rRNA gene and the ITS-rDNA regions, respectively. Bacterial and fungal communities from the forest plantation, compared to those from natural forest soils, showed different community structure and lower α-diversity values, consistently with the significantly higher pH values and lower organic matter content of those soils. β-diversity values, the number of measured and estimated dominant OTUs, and their distribution among the three sites showed that microbial communities from the two natural forests were much more similar to each other than they were to communities from the poplar plantation, suggesting an effect of the forest conversion on the composition and diversity of soil microbial communities. α-diversity in cultivated forest soils had narrower temporal fluctuations than in natural forest soils, suggesting higher temporal stability of microbial communities. Overall, we demonstrated that the conversion from natural forest to forest plantation altered soil microbial communities, changing their structure, lowering their diversity, and causing a spatial and temporal homogenization. PMID:26686617

  7. Diurnal and Seasonal Variation of Isoprene Biosynthesis-Related Genes in Grey Poplar Leaves1

    PubMed Central

    Mayrhofer, Sabine; Teuber, Markus; Zimmer, Ina; Louis, Sandrine; Fischbach, Robert J.; Schnitzler, Jörg-Peter

    2005-01-01

    Transcript levels of mRNA from 1-deoxy-d-xylulose 5-phosphate reductoisomerase (PcDXR), isoprene synthase (PcISPS), and phytoene synthase (PcPSY) showed strong seasonal variations in leaves of Grey poplar (Populus × canescens [Aiton] Sm.). These changes were dependent on the developmental stage and were strongly correlated to temperature and light. The expression rates of the genes PcDXR and PcISPS were found to be significantly correlated to each other, whereas the expression of the PcPSY gene showed a different seasonal pattern. Protein concentration and enzyme activity of PcISPS showed distinct seasonal patterns peaking in late summer, whereas highest transcription levels of PcISPS were observed in early summer. Moreover, correlation between PcISPS protein concentration and enzyme activity changed, in particular in autumn, when PcISPS protein levels remained high while enzyme activity declined, indicating posttranslational modifications of the enzyme. The positive correlation between dimethylallyl diphosphate levels and PcISPS protein content was found to be consistent with the demonstrated synchronized regulation of PcDXR and PcISPS, suggesting that metabolic flux through the 1-deoxy-d-xylulose 5-phosphate pathway and isoprene emission capacity are closely intercoordinated. Transcript levels of PcISPS showed strong diurnal variation with maximal values before midday in contrast to PcDXR, whose gene expression exhibited no clear intraday changes. During the course of a day, in vitro PcISPS activities did not change, whereas leaf dimethylallyl diphosphate levels and isoprene emission showed strong diurnal variations depending on actual temperature and light profiles on the respective day. These results illustrate that the regulation of isoprene biosynthesis in Grey poplar leaves seems to happen on transcriptional, posttranslational, and metabolic levels and is highly variable with respect to seasonal and diurnal changes in relation to temperature and light. PMID

  8. The poplar Phi class glutathione transferase: expression, activity and structure of GSTF1.

    PubMed

    Pégeot, Henri; Koh, Cha San; Petre, Benjamin; Mathiot, Sandrine; Duplessis, Sébastien; Hecker, Arnaud; Didierjean, Claude; Rouhier, Nicolas

    2014-01-01

    Glutathione transferases (GSTs) constitute a superfamily of enzymes with essential roles in cellular detoxification and secondary metabolism in plants as in other organisms. Several plant GSTs, including those of the Phi class (GSTFs), require a conserved catalytic serine residue to perform glutathione (GSH)-conjugation reactions. Genomic analyses revealed that terrestrial plants have around ten GSTFs, eight in the Populus trichocarpa genome, but their physiological functions and substrates are mostly unknown. Transcript expression analyses showed a predominant expression of all genes both in reproductive (female flowers, fruits, floral buds) and vegetative organs (leaves, petioles). Here, we show that the recombinant poplar GSTF1 (PttGSTF1) possesses peroxidase activity toward cumene hydroperoxide and GSH-conjugation activity toward model substrates such as 2,4-dinitrochlorobenzene, benzyl and phenetyl isothiocyanate, 4-nitrophenyl butyrate and 4-hydroxy-2-nonenal but interestingly not on previously identified GSTF-class substrates. In accordance with analytical gel filtration data, crystal structure of PttGSTF1 showed a canonical dimeric organization with bound GSH or 2-(N-morpholino)ethanesulfonic acid molecules. The structure of these protein-substrate complexes allowed delineating the residues contributing to both the G and H sites that form the active site cavity. In sum, the presence of GSTF1 transcripts and proteins in most poplar organs especially those rich in secondary metabolites such as flowers and fruits, together with its GSH-conjugation activity and its documented stress-responsive expression suggest that its function is associated with the catalytic transformation of metabolites and/or peroxide removal rather than with ligandin properties as previously reported for other GSTFs. PMID:25566286

  9. Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour.

    PubMed

    Madejón, Paula; Cantos, Manuel; Jiménez-Ramos, María C; Marañón, Teodoro; Murillo, José M

    2015-11-01

    Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons. PMID:26433900

  10. Moderate salt treatment alleviates ultraviolet-B radiation caused impairment in poplar plants.

    PubMed

    Ma, Xuan; Ou, Yong-Bin; Gao, Yong-Feng; Lutts, Stanley; Li, Tao-Tao; Wang, Yang; Chen, Yong-Fu; Sun, Yu-Fang; Yao, Yin-An

    2016-01-01

    The effects of moderate salinity on the responses of woody plants to UV-B radiation were investigated using two Populus species (Populus alba and Populus russkii). Under UV-B radiation, moderate salinity reduced the oxidation pressure in both species, as indicated by lower levels of cellular H2O2 and membrane peroxidation, and weakened the inhibition of photochemical efficiency expressed by O-J-I-P changes. UV-B-induced DNA lesions in chloroplast and nucleus were alleviated by salinity, which could be explained by the higher expression levels of DNA repair system genes under UV-B&salt condition, such as the PHR, DDB2, and MutSα genes. The salt-induced increase in organic osmolytes proline and glycine betaine, afforded more efficient protection against UV-B radiation. Therefore moderate salinity induced cross-tolerance to UV-B stress in poplar plants. It is thus suggested that woody plants growing in moderate salted condition would be less affected by enhanced UV-B radiation than plants growing in the absence of salt. Our results also showed that UV-B signal genes in poplar plants PaCOP1, PaSTO and PaSTH2 were quickly responding to UV-B radiation, but not to salt. The transcripts of PaHY5 and its downstream pathway genes (PaCHS1, PaCHS4, PaFLS1 and PaFLS2) were differently up-regulated by these treatments, but the flavonoid compounds were not involved in the cross-tolerance since their concentration increased to the same extent in both UV-B and combined stresses. PMID:27597726

  11. Calcium mediates root K+/Na+ homeostasis in poplar species differing in salt tolerance.

    PubMed

    Sun, Jian; Dai, Songxiang; Wang, Ruigang; Chen, Shaoliang; Li, Niya; Zhou, Xiaoyang; Lu, Cunfu; Shen, Xin; Zheng, Xiaojiang; Hu, Zanmin; Zhang, Zengkai; Song, Jin; Xu, Yue

    2009-09-01

    Using the non-invasively ion-selective microelectrode technique, flux profiles of K(+), Na(+) and H(+) in mature roots and apical regions, and the effects of Ca(2+) on ion fluxes were investigated in salt-tolerant poplar species, Populus euphratica Oliver and salt-sensitive Populus simonii x (P. pyramidalis + Salix matsudana) (Populus popularis 35-44, P. popularis). Compared to P. popularis, P. euphratica roots exhibited a greater capacity to retain K(+) after exposure to a salt shock (SS, 100 mM NaCl) and a long-term (LT) salinity (50 mM NaCl, 3 weeks). Salt shock-induced K(+) efflux in the two species was markedly restricted by K(+) channel blocker, tetraethylammonium chloride, but enhanced by sodium orthovanadate, the inhibitor of plasma membrane (PM) H(+)-ATPase, suggesting that the K(+) efflux is mediated by depolarization-activated (DA) channels, e.g., KORCs (outward rectifying K(+) channels) and NSCCs (non-selective cation channels). Populus euphratica roots were more effective to exclude Na(+) than P. popularis in an LT experiment, resulting from the Na(+)/H(+) antiport across the PM. Moreover, pharmacological evidence implies that the greater ability to control K(+)/Na(+) homeostasis in salinized P. euphratica roots is associated with the higher H(+)-pumping activity, which provides an electrochemical H(+) gradient for Na(+)/H(+) exchange and simultaneously decreases the NaCl-induced depolarization of PM, thus reducing Na(+) influx via NSCCs and K(+) efflux through DA-KORCs and DA-NSCCs. Ca(2+) application markedly limited salt-induced K(+) efflux but enhanced the apparent Na(+) efflux, thus enabling the two species, especially the salt-sensitive poplar, to retain K(+)/Na(+) homeostasis in roots exposed to prolonged NaCl treatment. PMID:19638360

  12. Transpiration and water relations of poplar trees growing close to the water table.

    PubMed

    Zhang, Heping; Morison, James I. L.; Simmonds, Lester P.

    1999-07-01

    Sap flow was measured on five branches of two poplar (Populus trichocarpa Torr. & A. Gray x P. tacamahaca L.) trees from June to September 1994 in the south of England with stem-surface, heat balance gauges, and was scaled up to estimate transpiration from single trees on the basis of leaf area. On six days, stomatal conductance and plant water potential were measured simultaneously with a porometer and pressure chamber, respectively. The effects of solar radiation (S), vapor pressure deficit (D) and stomatal conductance on transpiration were evaluated. Sap flow per unit leaf area (F(a)) was closely related to the time course of demand attributable to S and D throughout the season, and only slightly affected by the water content of the top 120 cm of soil. Although F(a) increased linearly at low values of D, it showed a plateau with increases in D above 1.2 kPa. The canopy coupling coefficient (1 - Omega) ranged from 0.48 to 0.78 with a mean of 0.65 +/- 0.01, indicating that transpiration was controlled more by stomatal conductance than by incident radiation. The seasonal pattern of tree water loss followed potential evaporation with a peak in late June or early July. On bright days, daily transpiration over the projected crown area was 3.6 mm early in the season, 3.8 mm in mid-season, and 2.7 mm late in the season. The water balance of the system indicated that poplar trees took 15-60% of water transpired from groundwater, with the proportion increasing as the soil in the unsaturated zone dried out. Access to the water table resulted in high predawn water potentials throughout the season. Estimated hydraulic resistance to water flow in the soil-tree system was in the range of 1.5 to 1.93 x 10(6) MPa s m(-3). PMID:12651530

  13. Transport of gold nanoparticles through plasmodesmata and precipitation of gold ions in woody poplar.

    PubMed

    Zhai, Guangshu; Walters, Katherine S; Peate, David W; Alvarez, Pedro J J; Schnoor, Jerald L

    2014-02-11

    Poplar plants (Populus deltoides × nigra, DN-34) were used as a model to explore vegetative uptake of commercially available gold nanoparticles (AuNPs) and their subsequent translocation and transport into plant cells. AuNPs were directly taken up and translocated from hydroponic solution to poplar roots, stems and leaves. Total gold concentrations in leaves of plants treated with 15, 25 and 50 nm AuNPs at exposure concentrations of 498±50.5, 247±94.5 and 263±157 ng/mL in solutions were: 0.023±0.006, 0.0218±0.004 and 0.005±0.0003 µg/g dry weight, respectively, which accounted for 0.05, 0.10 and 0.03%, respectively, of the total gold mass added. The presence of total gold in plant tissues was measured by inductively coupled plasma mass spectrometry, while AuNPs were observed by transmission electron microscopy in plant tissues. In solution, AuNPs were distinguished from Au(III) ions by membrane separation and centrifugation. AuNPs behaved conservatively inside the plants and were not dissolved into gold ions. On the other hand, Au(III) ions were taken up and reduced into AuNPs inside whole plants. AuNPs were observed in the cytoplasm and various organelles of root and leaf cells. A distinct change in color from yellow to pink was observed as Au(III) ions were reduced and precipitated in hydroponic solution. The accumulation of AuNPs in the plasmodesma of the phloem complex in root cells clearly suggests ease of transport between cells and translocation throughout the whole plant, inferring the potential for entry and transfer in food webs. PMID:25386566

  14. Stellarator hybrids

    SciTech Connect

    Furth, H.P.; Ludescher, C.

    1984-08-01

    The present paper briefly reviews the subject of tokamak-stellarator and pinch-stellarator hybrids, and points to two interesting new possibilities: compact-torus-stellarators and mirror-stellarators.

  15. EVALUATION OF HYBRID POPLAR TREE TOLERANCE TO IRRIGATION WITH HIGH SALINITY AND BORON WATERS UNDER MICRO-PLOT CONDITIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of reusing salt-laden drainage water in agricultural systems was developed as part of the integrated on-farm drainage management system. The successful adoption of a practical water reuse strategy in Central California requires the selection of salt and boron tolerant crops for use with ...

  16. Hydrochemical dynamics of stream water during snowmelt under differing soil frost regimes in a northern hardwood forest

    NASA Astrophysics Data System (ADS)

    Fuss, C. B.; Driscoll, C. T.; Green, M. B.; Groffman, P. M.

    2012-12-01

    Winter climate change is expected to alter the snowpack accumulation as well as the timing and magnitude of snowmelt events in northern hardwood forests. Additionally, lower snowpacks associated with climate change have been hypothesized to increase soil freezing events. Soil freezing has been associated with increases in acidity and the leaching of nitrate, but the observed effects are inconsistent, especially when comparing the plot and watershed scales. Snowmelt is a large portion of the annual hydrologic flux in northern hardwood forest catchments and characterized by acidic conditions, which can be deleterious for downstream water quality. The objectives of our study were to characterize the hydrochemical dynamics longitudinally within watersheds under differing climatic conditions and to determine if inconsistencies in observed responses to soil freezing can be explained by changes in hydrologic flowpaths associated with soil frost. We measured major solute chemistry in daily stream water samples collected throughout the snowmelt periods of 2010, 2011, and 2012 at the Hubbard Brook Experimental Forest, NH, USA. Samples were collected at the gauging station of three different watersheds (two south-facing and one north-facing) and at a higher elevation site (approximately 100 m higher than the gauging station) in one south-facing and one north-facing watershed). This sampling scheme was designed to take advantage natural differences in snow depth and soil freezing between and within watersheds. We found generally more acidic drainage water with greater flushing of nitrate (NO3-) and dissolved organic carbon (DOC) in the higher elevation sampling sites of the watersheds. Changes in solute chemistry with flow rate were more pronounced at the base of the watershed where the deeper soil profile at lower elevation allowed for more variation in hydrologic flowpaths compared to the shallow higher elevation soils. For example, changes in stream NO3- concentration

  17. Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

    SciTech Connect

    Chandrashekhar P. Joshi; Vincent L. Chiang

    2009-01-29

    Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for the biosynthesis of G lignin. However, in hardwoods, three additional genes branch out from the G-lignin pathway and become specifically engaged in regulating S lignin biosynthesis. In this research, we simultaneously transferred aspen S-specific genes into a model softwood, black spruce, to engineer S lignin.

  18. Seasonal variation in the structure of red reflectance of leaves from yellow poplar, red oak, and red maple

    NASA Technical Reports Server (NTRS)

    Brakke, Thomas W.; Wergin, William P.; Erbe, Eric F.; Harnden, Joann M.

    1993-01-01

    The light scattered from leaves was measured as a function of view angle in the principal plane for yellow poplar, red oak, and red maple. The source was a parallel-polarized helium-neon laser. Yellow poplar leaves had the highest reflectance of the three species, which may have been due to its shorter palisade cells and more extensive spongy mesophyll. Prior to senescence, there was a significant decrease, but not total extinction, in the reflectance of the beam incident at 60 deg from nadir on the adaxial side of the leaves of all three species. Low-temperature SEM observations showed differences in the surface wax patterns among the three species but did not indicate a cause of the reflectance changes other than possibly the accumulation and aging of the wax.

  19. Comparison of three types of traps baited with sexual pheromones for ambrosia beetle Megaplatypus mutatus (Coleoptera: Platypodinae) in poplar plantations.

    PubMed

    Funes, Hernán; Zerba, Eduardo; González Audino, Paola

    2009-08-01

    Megaplatypus mutatus (Coleoptera: Platypodinae) is an ambrosia beetle native to South America that only attacks standing live trees and is a serious problem for commercial poplar (Populus L.; Salicaceae) plantations in Argentina. The development of traps baited with synthetic pheromones that can be used for monitoring M. mutatus in infested poplar plantations is an important goal in preventive programs. Pioneer male M. mutatus emit a pheromone composed mainly by (+)-sulcatol and sulcatone. In the current study, we tested their release rates from several polymeric reservoir systems, to develop and manufacture a pheromone-releasing device. The efficacy of three different types of traps was evaluated in the field. Single funnel traps equipped with cross-vanes (CIPEIN-CV) captured significantly more insects than multiple funnel traps (LINDGREN) and simple funnel traps (CIPEIN-F). PMID:19736767

  20. Understanding of pH value and its effect on autohydrolysis pretreatment prior to poplar chemi-thermomechanical pulping.

    PubMed

    Liu, Lihui; Liu, Wei; Hou, Qingxi; Chen, Junwei; Xu, Ningpan

    2015-11-01

    Autohydrolysis pretreatment with different severity factors was performed on poplar chips prior to chemi-thermomechanical pulping (CTMP) in order to investigate the change in pH value and its effect on the autohydrolysis pretreatment. The results showed that the dissolution amount of acetic acid increased with raising the severity factor of the pretreatment and declining the size of poplar chips, respectively. Besides, a logarithmic relationship between the amount of acetic acid released in the autohydrolysis liquor (AHL) and pH value of the AHL was observed. The amounts of glucose and xylose (including those in the form of monomers, oligomers, and polysaccharides) as well as furfural and hydroxymethylfurfural (HMF) also depended on the pH value of the AHL to some extent. PMID:26313534

  1. An Improved Approach for Mapping Quantitative Trait loci in a Pseudo-Testcross: Revisiting a Poplar Mapping Study

    SciTech Connect

    Wullschleger, Stan D; Wu, Song; Wu, Rongling; Yang, Jie; Li, Yao; Yin, Tongming; Tuskan, Gerald A

    2010-01-01

    A pseudo-testcross pedigree is widely used for mapping quantitative trait loci (QTL) in outcrossing species, but the model for analyzing pseudo-testcross data borrowed from the inbred backcross design can only detect those QTLs that are heterozygous only in one parent. In this study, an intercross model that incorporates the high heterozygosity and phase uncertainty of outcrossing species was used to reanalyze a published data set on QTL mapping in poplar trees. Several intercross QTLs that are heterozygous in both parents were detected, which are responsible not only for biomass traits, but also for their genetic correlations. This study provides a more complete identification of QTLs responsible for economically important biomass traits in poplars.

  2. An Improved Approach for Mapping Quantitative Trait Loci in a Pseudo-Testcross: Revisiting a Poplar Mapping Study

    SciTech Connect

    Tuskan, Gerald A; Yin, Tongming; Wullschleger, Stan D; Yang, Jie; Huang, Youjun; Li, Yao; Wu, Rongling

    2010-01-01

    A pseudo-testcross pedigree is widely used for mapping quantitative trait loci (QTL) in outcrossing species, but the model for analyzing pseudo-testcross data borrowed from the inbred backcross design can only detect those QTLs that are heterozygous only in one parent. In this study, an intercross model that incorporates the high heterozygosity and phase uncertainty of outcrossing species was used to reanalyze a published data set on QTL mapping in poplar trees. Several intercross QTLs that are heterozygous in both parents were detected, which are responsible not only for biomass traits, but also for their genetic correlations. This study provides a more complete identification of QTLs responsible for economically important biomass traits in poplars.

  3. The relationship between isoprene emission, CO(2) assimilation and water use efficiency across a range of poplar genotypes.

    PubMed

    Guidolotti, Gabriele; Calfapietra, Carlo; Loreto, Francesco

    2011-07-01

    Poplars (Populus sp.) are among the strongest isoprene (Iso)-emitting plants. Ten poplar genotypes belonging to four different species were grown under the same environmental conditions in a common garden experiment, to study the influence of the genetic variability on Iso emission and on the relationship between Iso and photosynthesis. Photosynthesis ranged from 13 to 20 µmol CO(2) m(-2) s(-1) , whereas Iso emission ranged from 18.2 to 45.2 nmol m(-2) s(-1) . There was no clear association between Iso emission and photosynthesis. In most genotypes, photosynthetic capacity developed earlier than Iso emission capacity. The emission of Iso was inversely correlated with the intercellular CO(2) concentration (C(i) ) and positively correlated with instantaneous water use efficiency. It is speculated that, by regulating C(i) , stomatal opening also indirectly controls Iso emission in poplars. A positive linear correlation between the fraction of recently assimilated carbon emitted as Iso and Iso emission rate was found. The slope of this relationship indicated that each nanomole of Iso emitted requires a fixed fraction of photosynthetic carbon regardless of the intra- and interspecific variability in the Populus genus, and of leaf ontogeny. A comparison with data from recent studies showed that the slope of this relationship increases in drought-stressed leaves. However, this might be explained by an increasing contribution of carbon sources for Iso biosynthesis from stored photosynthates. If this is true, then the amount of carbon directly shunted from photosynthesis into Iso is constant in all poplars and is not influenced by abiotic stresses. PMID:21361963

  4. Confirmatory Sampling and Analysis Plan for the Lower East Fork Poplar Creek Operable Unit, Oak Ridge, Tennessee

    SciTech Connect

    1996-12-01

    This document describes the organization, strategy, and procedures to be used to confirm that mercury concentrations in soils in the remediated areas are statistically less than, or equal to, the cleanup standard of 400 ppm. It focuses on confirming the cleanup of the stretch of the Lower East Fork Popular Creed flowing from Lake Reality at the Y-12 Plant, through the City of Oak Ridge, to Poplar Creek on the Oak Ridge Reservation and its associated flood plain.

  5. Interaction between isoprene and ozone fluxes at ecosystem level in a poplar plantation and its impact at European level

    NASA Astrophysics Data System (ADS)

    Zenone, T.; Hendriks, C.; Brilli, F.; Gioli, B.; Portillo Estrada, M.; Schaap, M.; Ceulemans, R.

    2015-12-01

    The emissions of Biogenic volatile organic compounds (BVOCs) from vegetation, mainly in form of isoprenoids, play an important role in the tropospheric ozone (O3) formation. The potential large expansion of isoprene emitter species (e.g. poplar) as biofuels feedstock might impact the ground level O3 formation. Here we report the simultaneous observations, using the eddy covariance (EC) technique, of isoprene, O3 and CO2 fluxes in a short rotation coppice (SRC) of poplar. The impact of current poplar plantations and associated isoprene emissions on ground level ozone concentrations for Europe was evaluated using a chemistry transport model (CTM) LOTOS-EUROS. The isoprene fluxes showed a well-defined seasonal and daily cycle that mirrored with the stomata O3 uptake. The isoprene emission and the stomata O3 uptake showed significant statistical relationship especially at elevated temperature. Isoprene was characterized by a remarkable peak of emissions (e.g. 38 nmol m-2s-1) occurring for few days as a consequence of the rapid variation of the air and surface temperature. During these days the photosynthetic apparatus (i.e. the CO2 fluxes) and transpiration rates did not show significant variation while we did observe a variation of the energy exchange and a reduction of the bowen ratio. The response of isoprene emissions to ambient O3 concentration follows the common form of the hormetic dose-response curve with a considerable reduction of the isoprene emissions at [O3] > 80 ppbv indicating a potential damping effect of the O3 levels on isoprene. Under the current condition the impact of SRC plantations on ozone concentrations / formation is very limited in Europe. Our findings indicate that, even with future scenarios with more SRC, or conventional poplar plantations, the impact on Ozone formation is negligible.

  6. Impact of ectomycorrhizal colonization and rust infection on the secondary metabolism of poplar (Populus trichocarpa x deltoides).

    PubMed

    Pfabel, Cornelia; Eckhardt, Kai-Uwe; Baum, Christel; Struck, Christine; Frey, Pascal; Weih, Martin

    2012-11-01

    Fungal colonization can significantly affect the secondary metabolism of the host plants. We tested the impact of a common below-ground symbiosis, i.e., ectomycorrhiza formation, on poplar leaf chemical components that are involved in the defence against a common disease, i.e., rust fungi, in N-deficient soil. A rust-susceptible poplar clone (Populus trichocarpa × deltoides 'Beaupré') was (a) non-associated with ectomycorrhizal fungus (EM) Hebeloma mesophaeum (Pers.) Quélet MÜN and non-infected with rust fungus Melampsora larici-populina Kleb. (isolate 98AG31), (b) associated with EM, (c) inoculated with rust fungus and (d) associated with EM and inoculated with rust fungus. Poplar leaves were analysed by photometric and mass spectrometric techniques (liquid chromatography-tandem mass spectrometry (LC-MS/MS), pyrolysis-field ionization mass spectrometry (Py-FIMS)). Both rust infection and mycorrhiza formation led to increased proportions of condensed tannins in relation to total phenolics (13% in the control, 18-19% in the fungal treatments). In contrast, salicylic acid concentration (6.8 µg g(-1) in the control) was higher only in the rust treatments (17.9 and 25.4 µg g(-1) with rust infection). The Py-FIMS analysis revealed that the rust-infected treatments were significantly separated from the non-rust-infected treatments on the basis of six flavonoids and one lipid. The relative abundance of these components, which have known functions in plant defence, was decreased after rust infection of non-mycorrhizal plants, but not in mycorrhizal plants. The results indicate that the ectomycorrhizal formation compensated the rust infection by a decrease in the flavonoid syntheses. The study provides new evidence for an interactive response of mycorrhizal colonization and infection with rust fungi in the metabolism of poplar. PMID:23065191

  7. Characterisation of the willow phenylalanine ammonia-lyase (PAL) gene family reveals expression differences compared with poplar

    PubMed Central

    de Jong, Femke; Hanley, Steven J.; Beale, Michael H.; Karp, Angela

    2015-01-01

    Willow is an important biomass crop for the bioenergy industry, and therefore optimal growth with minimal effects of biotic and abiotic stress is essential. The phenylpropanoid pathway is responsible for the biosynthesis of not only lignin but also of flavonoids, condensed tannins, benzenoids and phenolic glycosides which all have a role in protecting the plant against biotic and abiotic stress. All products of the phenylpropanoid pathway are important for the healthy growth of short rotation cropping species such as willow. However, the phenylpropanoid pathway in willow remains largely uncharacterised. In the current study we identified and characterised five willow phenylalanine ammonia-lyase (PAL) genes, which encode enzymes that catalyse the deamination of l-phenylalanine to form trans-cinnamic acid, the entry point into the phenylpropanoid pathway. Willow PAL1, PAL2, PAL3 and PAL4 genes were orthologous to the poplar genes. However no orthologue of PAL5 appears to be present in willow. Moreover, two tandemly repeated PAL2 orthologues were identified in a single contig. Willow PALs show similar sub-cellular localisation to the poplar genes. However, the enzyme kinetics and gene expression of the willow PAL genes differed slightly, with willow PAL2 being more widely expressed than its poplar orthologues implying a wider role for PALs in the production of flavonoids, condensed tannins, benzenoids, and phenolic glycosides, in willow. PMID:26070140

  8. RNAi-mediated downregulation of poplar plasma membrane intrinsic proteins (PIPs) changes plasma membrane proteome composition and affects leaf physiology.

    PubMed

    Bi, Zhen; Merl-Pham, Juliane; Uehlein, Norbert; Zimmer, Ina; Mühlhans, Stefanie; Aichler, Michaela; Walch, Axel Karl; Kaldenhoff, Ralf; Palme, Klaus; Schnitzler, Jörg-Peter; Block, Katja

    2015-10-14

    Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement. PMID:26248320

  9. Monitoring the effect of poplar trees on petroleum-hydrocarbon and chlorinated-solvent contaminated ground water

    USGS Publications Warehouse

    Landmeyer, J.E.

    2001-01-01

    At contaminated groundwater sites, poplar trees can be used to affect groundwater levels, flow directions, and ultimately total groundwater and contaminant flux to areas downgradient of the trees. The magnitude of the hydrologic changes can be monitored using fundamental concepts of groundwater hydrology, in addition to plant physiology-based approaches, and can be viewed as being almost independent of the contaminant released. The affect of poplar trees on the fate of groundwater contaminants, however, is contaminant dependent. Some petroleum hydrocarbons or chlorinated solvents may be mineralized or transformed to innocuous compounds by rhizospheric bacteria associated with the tree roots, mineralized or transformed by plant tissues in the transpiration stream or leaves after uptake, or passively volatilized and rapidly dispersed or oxidized in the atmosphere. These processes also can be monitored using a combination of physiological- or geochemical-based field or laboratory approaches. When combined, such hydrologic and contaminant monitoring approaches can result in a more accurate assessment of the use of poplar trees to meet regulatory goals at contaminated groundwater sites, verify that these goals continue to be met in the future, and ultimately lead to a consensus on how the performance of plant-based remedial strategies (phytoremediation) is to be assessed.

  10. Transgenic poplar expressing Arabidopsis YUCCA6 exhibits auxin-overproduction phenotypes and increased tolerance to abiotic stress.

    PubMed

    Ke, Qingbo; Wang, Zhi; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Kwak, Sang-Soo

    2015-09-01

    YUCCA6, a member of the YUCCA family of flavin monooxygenase-like proteins, is involved in the tryptophan-dependent IAA biosynthesis pathway and responses to environmental cues in Arabidopsis. However, little is known about the role of the YUCCA pathway in auxin biosynthesis in poplar. Here, we generated transgenic poplar (Populus alba × P. glandulosa) expressing the Arabidopsis YUCCA6 gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SY plants). Three SY lines (SY7, SY12 and SY20) were selected based on the levels of AtYUCCA6 transcript. SY plants displayed auxin-overproduction morphological phenotypes, such as rapid shoot growth and retarded main root development with increased root hair formation. In addition, SY plants had higher levels of free IAA and early auxin-response gene transcripts. SY plants exhibited tolerance to drought stress, which was associated with reduced levels of reactive oxygen species. Furthermore, SY plants showed delayed hormone- and dark-induced senescence in detached leaves due to higher photosystem II efficiency and less membrane permeability. These results suggest that the conserved IAA biosynthesis pathway mediated by YUCCA family members exists in poplar. PMID:25980973

  11. Determination of As in tree-rings of poplar (Populus alba L.) by U-shaped DC arc.

    PubMed

    Marković, D M; Novović, I; Vilotić, D; Ignjat