bluuebunny/crossref_metadata_2025 huggingface dataset:
Method To Detect Only Live Bacteria during PCR Amplification
Authors: Soejima Takashi , Iida Ken-ichiro , Qin Tian , Taniai Hiroaki , Seki Masanori , Yoshida Shin-ichi
Published: May 2008

Ethidium monoazide (EMA) is a DNA cross-linking agent and eukaryotic topoisomerase II poison. We previously reported that the treatment of EMA with visible light irradiation (EMA + Light) directly cleaved chromosomal DNA ofEscherichia coli(T. Soejima, K. Iida, T. Qin, H. Taniai, M. Seki, A. Takade, and S. Yoshida, Microbiol. Immunol.51:763-775, 2007). Herein, we report that EMA + Light randomly cleaved chromosomal DNA of heat-treated, but not live,Listeria monocytogenescells within 10 min of treatment. When PCR amplified DNA that was 894 bp in size, PCR final products from 108heat-treatedL. monocytogeneswere completely suppressed by EMA + Light. When target DNA was short (113 bp), like thehlygene ofL. monocytogenes, DNA amplification was not completely suppressed by EMA + Light only. Thus, we used DNA gyrase/topoisomerase IV and mammalian topoisomerase poisons (here abbreviated as T-poisons) together with EMA + Light. T-poisons could penetrate heat-treated, but not live,L. monocytogenescells within 30 min to cleave chromosomal DNA by poisoning activity. The PCR product of thehlygene from 108heat-treatedL. monocytogenescells was inhibited by a combination of EMA + Light and T-poisons (EMA + Light + T-poisons), but those from live bacteria were not suppressed. As a model for clinical application to bacteremia, we tried to discriminate live and antibiotic-treatedL. monocytogenescells present in human blood. EMA + Light + T-poisons completely suppressed the PCR product from 103to 107antibiotic-treatedL. monocytogenescells but could detect 102live bacteria. Considering the prevention and control of food poisoning, this method was applied to discriminate live and heat-treatedL. monocytogenescells spiked into pasteurized milk. EMA + Light + T-poisons inhibited the PCR product from 103to 107heat-treated cells but could detect 101liveL. monocytogenescells. Our method is useful in clinical as well as food hygiene tests.
The Temperate Marine Phage ΦHAP-1 of
Halomonas aquamarina
Possesses a Linear Plasmid-Like Prophage Genome
Authors: Mobberley Jennifer M. , Authement R. Nathan , Segall Anca M. , Paul John H.
Published: May 2008

A myovirus-like temperate phage, ΦHAP-1, was induced with mitomycin C from a
Halomonas aquamarina
strain isolated from surface waters in the Gulf of Mexico. The induced cultures produced significantly more virus-like particles (VLPs) (3.73 × 10
10
VLP ml
−1
) than control cultures (3.83 × 10
7
VLP ml
−1
) when observed with epifluorescence microscopy. The induced phage was sequenced by using linker-amplified shotgun libraries and contained a genome 39,245 nucleotides in length with a G+C content of 59%. The ΦHAP-1 genome contained 46 putative open reading frames (ORFs), with 76% sharing significant similarity (E value of <10
−3
) at the protein level with other sequences in GenBank. Putative functional gene assignments included small and large terminase subunits, capsid and tail genes, an N6-DNA adenine methyltransferase, and lysogeny-related genes. Although no integrase was found, the ΦHAP-1 genome contained ORFs similar to protelomerase and
parA
genes found in linear plasmid-like phages with telomeric ends. Southern probing and PCR analysis of host genomic, plasmid, and ΦHAP-1 DNA indicated a lack of integration of the prophage with the host chromosome and a difference in genome arrangement between the prophage and virion forms. The linear plasmid prophage form of ΦHAP-1 begins with the protelomerase gene, presumably due to the activity of the protelomerase, while the induced phage particle has a circularly permuted genome that begins with the terminase genes. The ΦHAP-1 genome shares synteny and gene similarity with coliphage N15 and vibriophages VP882 and VHML, suggesting an evolutionary heritage from an N15-like linear plasmid prophage ancestor.
Hepatitis B Virus HBx Protein Localizes to Mitochondria in Primary Rat Hepatocytes and Modulates Mitochondrial Membrane Potential
Authors: Clippinger Amy J. , Bouchard Michael J.
Published: May 2008

Over 350 million people are chronically infected with hepatitis B virus (HBV), and a significant number of chronically infected individuals develop primary liver cancer. HBV encodes seven viral proteins, including the nonstructural X (HBx) protein. The results of studies with immortalized or transformed cells and with HBx-transgenic mice demonstrated that HBx can interact with mitochondria. However, no studies with normal hepatocytes have characterized the precise mitochondrial localization of HBx or the effect of HBx on mitochondrial physiology. We have used cultured primary rat hepatocytes as a model system to characterize the mitochondrial localization of HBx and the effect of HBx expression on mitochondrial physiology. We now show that a fraction of HBx colocalizes with density-gradient-purified mitochondria and associates with the outer mitochondrial membrane. We also demonstrate that HBx regulates mitochondrial membrane potential in hepatocytes and that this function of HBx varies depending on the status of NF-κB activity. In primary rat hepatocytes, HBx activation of NF-κB prevented mitochondrial membrane depolarization; however, when NF-κB activity was inhibited, HBx induced membrane depolarization through modulation of the mitochondrial permeability transition pore. Collectively, these results define potential pathways through which HBx may act in order to modulate mitochondrial physiology, thereby altering many cellular activities and ultimately contributing to the development of HBV-associated liver cancer.
Enhanced Mucosal Immunoglobulin A Response and Solid Protection against Foot-and-Mouth Disease Virus Challenge Induced by a Novel Dendrimeric Peptide
Authors: Cubillos Carolina , de la Torre Beatriz G. , Jakab Annamaria , Clementi Giorgia , Borrás Eva , Bárcena Juan , Andreu David , Sobrino Francisco , Blanco Esther
Published: May 2008

The successful use of a dendrimeric peptide to protect pigs against challenge with foot-and-mouth disease virus (FMDV), which causes the most devastating animal disease worldwide, is described. Animals were immunized intramuscularly with a peptide containing one copy of a FMDV T-cell epitope and branching out into four copies of a B-cell epitope. The four immunized pigs did not develop significant clinical signs upon FMDV challenge, neither systemic nor mucosal FMDV replication, nor was its transmission to contact control pigs observed. The dendrimeric construction specifically induced high titers of FMDV-neutralizing antibodies and activated FMDV-specific T cells. Interestingly, a potent anti-FMDV immunoglobulin A response (local and systemic) was observed, despite the parenteral administration of the peptide. On the other hand, peptide-immunized animals showed no antibodies specific of FMDV infection, which qualifies the peptide as a potential marker vaccine. Overall, the dendrimeric peptide used elicited an immune response comparable to that found for control FMDV-infected pigs that correlated with a solid protection against FMDV challenge. Dendrimeric designs of this type may hold substantial promise for peptide subunit vaccine development.
A Seven-Segmented Influenza A Virus Expressing the Influenza C Virus Glycoprotein HEF
Authors: Gao Qinshan , Brydon Edward W. A. , Palese Peter
Published: May 2008

Influenza viruses are classified into three types: A, B, and C. The genomes of A- and B-type influenza viruses consist of eight RNA segments, whereas influenza C viruses only have seven RNAs. Both A and B influenza viruses contain two major surface glycoproteins: the hemagglutinin (HA) and the neuraminidase (NA). Influenza C viruses have only one major surface glycoprotein, HEF (hemagglutinin-esterase fusion). By using reverse genetics, we generated two seven-segmented chimeric influenza viruses. Each possesses six RNA segments from influenza virus A/Puerto Rico/8/34 (PB2, PB1, PA, NP, M, and NS); the seventh RNA segment encodes either the influenza virus C/Johannesburg/1/66 HEF full-length protein or a chimeric protein HEF-Ecto, which consists of the HEF ectodomain and the HA transmembrane and cytoplasmic regions. To facilitate packaging of the heterologous segment, both the HEF and HEF-Ecto coding regions are flanked by HA packaging sequences. When introduced as an eighth segment with the NA packaging sequences, both viruses are able to stably express a green fluorescent protein (GFP) gene, indicating a potential use for these viruses as vaccine vectors to carry foreign antigens. Finally, we show that incorporation of a GFP RNA segment enhances the growth of seven-segmented viruses, indicating that efficient influenza A viral RNA packaging requires the presence of eight RNA segments. These results support a selective mechanism of viral RNA recruitment to the budding site.
Nitrogen assimilation and regulation of nitrate and nitrite reductases in cultured Ipomoea cells
Authors: Zink M. W. , Veliky I. A.
Published: May 2008

Ipomoea cells grown in a medium containing ammonium and nitrate preferentially used ammonium during the initial stages of growth but in the later stages assimilated nitrate rapidly regardless of the presence or absence of ammonium. Cells grown on nitrate and maintained at pH 4.8 released ammonia into the medium, whereas when they were maintained at pH 6.5 they secreted nitrite. The enzymes of nitrate assimilation were inducible by nitrate and the activities changed considerably in response to nitrogen source. The addition of ammonium 3 days after inoculation to cells highly induced for the reductases did not result in the suppression of further synthesis of the enzymes. The levels of nitrate (EC 1.6.6.1) and nitrite (EC 1.6.6.4) reductases detected in cells grown on ammonium as the nitrogen source were about 25% and 66%, respectively, of the fully induced level. The addition of nitrate to ammonium-assimilating cells resulted in a low level of induction of both reductases. Addition of nitrite had no effect. With both ammonium and nitrate initially present in the medium, the ammonium was utilized quickly but no induction of the reductases was observed for 24 h. the time interval when the assimilation of nitrate was low. This was followed by the induction of the enzymes to a higher level than the activity in cultures of similar age that had been grown continually in nitrate, supplied at the same concentration. Thus, for nitrate and nitrite reductases, repression-like effects were produced by ammonium.
Deux Laboulbéniales (Ascomycetes) nouvelles, parasites de Zuphiini (Coleoptera, Carabidae)
Authors: Rossi Walter , Rossi M. Graziella Cesari
Published: May 2008

Two new Laboulbeniales occurring on African Zuphiini are described: Eucantharomyces basilewskyi, parasitic on Zuphium spp., and Laboulbenia cajanii, parasitic on Paraleleupidia uvirana Basilw.
An investigation into the influence of IAA and malate on in vivo and in vitro rates of dark carbon dioxide fixation in coleoptile tissue
Authors: Dymock I. J. , Hill B. , Bown A. W.
Published: May 2008

Etiolated Avena sativa L. cv. Victory coleoptiles were used to determine the influence of indoleacetic acid (IAA) or malate on in vivo and in vitro rates of CO2 fixation. In addition, the influence of malate on IAA-stimulated growth was investigated. Concentrations of malate which stimulate growth did not influence the in vivo rate of dark [14C]bicarbonate fixation but did inhibit in vitro phosphoenolpyruvate carboxylase (EC 4.1.1.31) activity. IAA did not influence this enzymic activity or reduce the inhibition of the enzyme by malate, and the rate of [14C]bicarbonate fixation was not measurably influenced by 20 μM IAA within the time period required for IAA stimulation of growth to become apparent. In the absence of atmospheric levels of CO2, 1 mM malate and 20 μM IAA stimulate growth in a weakly synergistic manner. These results are discussed in relationship to a suggestion that IAA-stimulated H+ secretion and growth involves a rapid effect on CO2 fixation.
Interactions entre mitochondries et chloroplastes dans la cellule. II. Action du DBMIB, de l'antimycine A et du FCCP sur la spore de Funaria hygrometrica
Authors: Chevallier D. , Douce R. , Nurit F.
Published: May 2008

The effect of DBMIB, antimycine A, and FCCP on respiration and photosynthesis of intact chlorophyllic moss (Funaria hygrometrica) spore was investigated.Antimycine A (1 μM) strongly inhibited dark respiration, was without effect on photosynthesis at high light intensities (above the saturation plateau values), and stimulated photosynthesis at low light intensities (below the saturation plateau values).DBMIB (3 μM) inhibited photosynthesis and was without effect, even under light conditions, on the dark respiration. Low amount of FCCP (3 μM) partially inhibited oxygen production at high light intensities. In this case, the inhibition observed was partially relieved by 1 μM antimycine A or 30 μM of KCN; higher concentration of FCCP totally inhibited the oxygen production.It seems likely, therefore, that in the chlorophyllic moss spore the cytochrome oxidase pathway is not functioning under high light intensities and that this inhibition of respiration is attributable to the low cytoplasmic ADP:ATP ratio.
Accuracy of aerial sketch-mapping estimates of spruce budworm defoliation in New Brunswick
Authors: MacLean David A. , MacKinnon Wayne E.
Published: May 2008

The accuracy of aerial sketch-mapping estimates of spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was evaluated from 1984 to 1993 in 222–325 sample plots in spruce (Picea sp.)–balsam fir (Abiesbalsamea (L.) Mill.) stands in New Brunswick. Operational aerial defoliation estimates were used, wherein all productive forest in known budworm infestation zones was surveyed each year from small aircraft with flight lines 2–5 km apart, and rated in classes of nil (0–10%), light (11–30%), moderate (31–70%), and severe (71–100%). Aerial defoliation estimates were compared with ground-based binocular estimates of current defoliation for an average of 10 trees/plot (range 5–20). Overall, 56% of plots were correctly rated by aerial sketch mapping in four classes (nil, light, moderate, and severe), with 37% of the plots underestimated and 7% overestimated. The predominant error (26% of plots) was rating defoliation as nil (0–10%) from the air when it was actually light (11–30%). This error was deemed not important in terms of predicting tree response, since data from the literature indicated that defoliation less than 30% did not cause tree mortality, although if continued, it would reduce growth. Using three defoliation classes (by combining nil and light, 0–30%), 82% of the plots were correctly classified by aerial sketch mapping. The probability of correct aerial classification of defoliation was significantly affected by defoliation class, weather conditions prior to and during observation flights, and the defoliation class × weather interaction. It was concluded that aerial sketch mapping of spruce budworm defoliation is a viable technique that can be used for both surveys and decision support systems that estimate forest response to budworm outbreaks and management activities.
A dendroecological assessment of whitebark pine in the Sawtooth–Salmon River region, Idaho
Authors: Perkins Dana L. , Swetnam Thomas W.
Published: May 2008

Whitebark pine (Pinusalbicaulis Engelm.) tree-ring chronologies of 700 to greater than 1000 years in length were developed for four sites in the Sawtooth–Salmon River region, central Idaho. These ring-width chronologies were used to (i) assess the dendrochronological characteristics of this species, (ii) detect annual mortality dates of whitebark pine attributed to a widespread mountain pine beetle (Dendroctonusponderosae Hopkins (Coleoptera: Scolytidae)) epidemic during the 1909–1940 period, and (iii) establish the response of whitebark pine ring-width growth to climate variables. Cross-dating of whitebark pine tree-ring patterns was verified. Ring-width indices had low mean sensitivity (0.123–0.174), typical of high-elevation conifers in western North America, and variable first-order autocorrelation (0.206–0.551). Mountain pine beetle caused mortality of dominant whitebark pine peaked in 1930 on all four sites. Response functions and correlation analyses with state divisional weather records indicate that above-average radial growth is positively correlated with winter and spring precipitation and inversely correlated with May temperature. These correlations appear to be a response to seasonal snowpack. Whitebark pine is a promising species for dendroclimatic studies.
Response of ectomycorrhizal and nonmycorrhizal pitch pine (Pinusrigida) seedlings to nutrient supply and aluminum: growth and mineral nutrition
Authors: Schier George A. , McQuattie Carolyn J.
Published: May 2008

Mycorrhizal colonization and nutrient supply may have important effects on aluminum toxicity in trees grown on acidic, nutrient-poor soils. The interacting effects of mycorrhizal inoculation, nutrient level, and Al treatment on growth and mineral nutrition of pitch pine (Pinusrigida Mill.) seedlings grown with and without the ectomycorrhizal fungus Pisolithustinctorius (Pers.) Coker & Couch were determined. The seedlings were grown for 66 days in sand irrigated with 0.1- or 0.2-strength nutrient solution (pH 3.8) containing 0, 10, or 20 mg/L Al (0, 0.37, or 0.74 mM). Across nutrient and Al levels total dry weight of ectomycorrhizal (ECM) seedlings was 75% greater than that of nonmycorrhizal (NM) seedlings. Doubling the nutrient level increased the dry weight of NM seedlings by 120%, versus 60% for ECM seedlings. Aluminum reduced root and shoot growth in NM seedlings, but had no effect on shoot growth and only a marginally significant effect on root growth of ECM seedlings. Shoot growth of NM seedlings was more sensitive to Al than root growth. Increased growth of NM seedlings by doubling the nutrient level was least at the highest Al level. Symptoms of Al toxicity in roots (dark, stunted tips) occurred at a lower Al level in NM than ECM seedlings. A strong relationship was not found between Al toxicity and concentrations of Mg and Ca in roots and needles. Enhancement of growth resulting from increased uptake of nutrients due to mycorrhizal inoculation (and) or an increased level of nutrients was the overriding factor affecting the response of pitch pine seedlings to Al.
Fine-root growth in beech (Fagussylvatica) forest gaps
Authors: Bauhus J. , Bartsch N.
Published: May 2008

The purpose of the study was to investigate fine-root growth in gaps created for beech (Fagussylvatica L.) regeneration. Fine-root growth was measured using the ingrowth core technique. Measurements were carried out in gaps 30 m in diameter, which were either untreated or treated with lime, and in a mature beech stand. Ingrowth core experiments showed that growth of beech fine roots in gap centres was negligible during the 2nd and 3rd year after gap creation, indicating that although fine roots from stumps stayed alive long after trees were cut, they did not grow. It also indicated that trees surrounding gaps did not effectively grow fine roots that reached 10 m into the gap centre. At the edge of unlimed gaps (5 m away from the stems), fine-root growth was one-third that of the mature stand. In the stand the amount of live fine roots in ingrowth cores (390 g•m−2) had attained the standing crop level after 16 months. In limed gaps, where herbaceous vegetation had established, herbaceous root growth was 800–970 g•m−2 after 16 months. Neither fine-root growth nor aboveground biomass of herbaceous plants was substantial in untreated gaps. The slow recovery of biomass production in unlimed gaps showed that the resistance of this beech forest to nutrient losses following disturbance is low.
Elemental dynamics of a Japanese watershed with sugi (Cryptomeriajaponica) and hinoki (Chamaecyparisobtuse) plantations
Authors: Ohrui Kiyokazu , Mitchell Myron J.
Published: May 2008

The roles of various components of the biogeochemical cycle in contributing to elemental loss or retention were evaluated in a Japanese watershed with 18-year-old plantations of sugi (Cryptomeriajaponica) and hinoki (Chamaecyparisobtusa). There was a large amount of foliar biomass (24.1 Mg•ha−1), which induced a large net increase of K+ (20.4 kg•ha−1•year−1) and consumption of H+ (0.26 kg•ha−1•year−1) in the canopy. Most of K+ in throughfall + stemflow was retained by vegetation increment. Although vegetation increment of N (33.9 kg N•ha−1•year−1) was larger than bulk precipitation N input (10.4 kg N•ha−1•year−1), high drainage loss of NO3− (13.6 kg N•ha−1•year−1) was observed. High N-mineralization and nitrification rates were suggested by high concentration of soil solution NO3− (315–434 μequiv.•L−1) and small forest floor N content. The high leaching rates of NO3− contributed to the high loss rates of Ca2+, the dominant cation in soil solution. The high N-mineralization and nitrification rates were likely due to the high temperature and moisture as well as the historical management of the watershed. High temperature and abundant moisture also accelerated chemical weathering of plagioclase, resulting in high drainage losses of HCO3−, Si, and Na+ and consumption of H+.
Relating jack pine budworm damage to stand inventory variables in northern Michigan
Authors: McCullough Deborah G. , Buss Lyle J. , Marshall Larry D. , Kouki Jari
Published: May 2008

Stand-level mortality and top kill from a 1991–1993 jack pine budworm (Choristoneurapinuspinus Freeman) outbreak were surveyed annually in the Raco Plains area of the Hiawatha National Forest in Michigan's Upper Peninsula from 1992 to 1994. Defoliation was visually estimated and percentage of trees killed or top killed was determined in 104 stands. In 1994, tree mortality attributable to the outbreak averaged 8% and 17% of trees had dead tops. Current stand inventory data, including age, site index, basal area, and size, were acquired from the Hiawatha Forest. Stands were grouped on the basis of inventory variables used for jack pine management in the Lake States region of the United States. Differences in tree mortality and top kill between groups, and associations between tree mortality and inventory variables, were evaluated. Tree mortality was greater in overmature stands and in overstocked stands, but stand size had little effect. Contrary to expectations, mortality was lower on poor sites with low site index values than on better sites with higher site index values. Mortality was not related to abundance of open-grown, full-canopied wolf trees or to abundance of trees infected with pine gall rust (Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka (=Peridermiumharknessii J.P. Moore)). Amount of top kill was related to defoliation severity and was higher in overmature and understocked stands. Top kill was not strongly associated with amount of tree mortality or with inventory variables.
Aboveground production efficiency and canopy nutrient contents of mixed-hardwood forest communities along a moisture gradient in the central United States
Authors: Jose Shibu , Gillespie Andrew R.
Published: May 2008

The significance of canopy nutrients in regulating aboveground production efficiency of mixed-hardwood forest communities (ecological land type phases, ELTPs) was examined along a moisture gradient in southern Indiana, U.S.A. A total of 39 plots were established in six ELTPs in which canopy specific leaf area, canopy nutrient contents (N, P, K, Ca, and Mg on unit leaf area basis and on unit leaf weight basis), light transmittance, aboveground net primary productivity, and production efficiency (on unit leaf area basis, i.e., Earea; and on unit leaf weight basis, i.e., Emass) were quantified. ELTPs exhibited significant differences in canopy specific leaf area and aboveground net primary productivity. Although Earea varied significantly among ELTPs, Emass exhibited no significant differences. Variation in canopy specific leaf area was significantly correlated with ELTP site water balance (R2 = 0.93, p = 0.0083). Along a decreasing moisture gradient, canopy specific leaf area decreased, which resulted in an increase in canopy nutrient content per unit leaf area. Canopy nutrient contents (N, P, and K) in turn exhibited strong positive correlations with Earea (no strong correlations with Emass), which increased along a decreasing moisture gradient. Higher canopy nutrient contents coupled with higher light transmittance through the canopy probably results in a higher canopy photosynthetic efficiency (area basis) in dry ELTPs. This is suggested as one of the reasons for higher Earea in dry ELTPs than in mesic ELTPs.
Temperature and Moisture Conditions on a Plowed Jack Pine Strip Cut in Southeastern Manitoba
Authors: Sims H. P.
Published: May 2008

Soil moisture, maximum surface temperatures, and duration of critical temperatures for jack pine (Pinusbanksiana Lamb.) seedlings were measured across a scarified east–west strip cut on a dry site in southeastern Manitoba. Temperature conditions were significantly less severe on the southern third of the strip and usually more favorable on the south side and in the trough of plowed furrows. Soil moisture remained within the available range [Formula: see text] at 3.8- and 7.6-cm depths under undisturbed and trough seedbeds throughout the growing season. Results indicate that moisture and temperature conditions lethal to germinants exist on all seedbeds of this site under weather conditons normally expected in the area. The more uniform moisture conditions under the trough seedbed suggest that it is most favorable for planting.
An Aggregation Method of Setting Cost-efficient Targets for Timber Production and Recreation Opportunities on Forested Land
Authors: Acar William , Smith Richard P.
Published: May 2008

This paper presents an integrated approach to the multiple-use planning of public land outside parks for the production of timber outputs and recreation opportunities, with actual administrative and budgeting processes. It is proposed that the production possibilities should be explored at the management unit level and aggregated upwards to provide district, regional, and provincial decision makers with their real planning alternatives together with the cost of them. In the aggregation process, the use of the cost-efficiency criterion allows the elimination of the less commendable alternatives. The method is straightforward and has been tested on a pilot study on the 8000-ha forest of the Leslie M. Frost Natural Resources Centre (Smith 1973). It allows a degree of control and feedback to senior administrative levels on the linkage between target setting and production potential. It would permit better coordination of these two management aspects, now determined independently.
Litter Fall after Wildfire in Virgin Forests of Northeastern Minnesota
Authors: Grigal David F. , McColl John G.
Published: May 2008

The Little Sioux Fire burned virgin forests in northeastern Minnesota on 14–17 May 1971. We monitored litter fall for 3 years after the fire in mixed conifer–deciduous forests both within and outside the fire boundaries. We separated four categories of litter: conifer needles, deciduous leaves, woody material, and miscellaneous material. Significantly more litter fell in the burned area during the 3 years (575 g/m2) than in the unburned areas (340 g/m2). Major differences were related to an increased fall of needles from conifers that had been killed by the fire and an increased fall of woody material from dead trees on the burn. Needles falling from these dead trees had significantly higher concentrations of N, P, and K and lower concentrations of Ca than did needles falling in the unburned areas. No other litter components showed significant differences in concentrations of N, P, K, Ca, and Mg between the burned and unburned areas for the 3 years of the study. By the 3rd year after the fire, less litter fell on the burn than on the unburned area, and the proportion of litter in all components except needles was similar in both areas.
Accumulation of Organic Matter in a Series of Douglas-fir Stands
Authors: Turner J. , Long James N.
Published: May 2008

The total aboveground biomass of a series of Douglas-fir stands which are located in western Washington increased with age while the foliar biomass and total crown biomass reached a steady state of about 11 000 kg/ha at between 40 and 50 years, depending upon stand density. Maximum wood productivity occurred near the time of crown closure, but the age of crown closure varied, with denser stands reaching crown closure at a younger age. Understory aboveground biomass and returns represented a significant portion of stand organic matter before crown closure but decreased in importance as the stand increased in age. In terms of relative contribution to stand organic matter, the vascular species of the understory were supplanted by mosses during the later stages of stand development. While the understory represented a small proportion of organic matter distribution, that is, less than 5% of standing plant biomass, it was a significant proportion of total productivity (up to 17%) and an even higher proportion of organic matter that was returned to the forest floor (up to 43% of total return). The forest floor in this series of stands did not reach a steady state but continued to increase in weight. The decomposition rate appeared to decrease with age.
Agrobacteriumtumefaciens, A Promoter of Wound Healing in Betulaalleghaniensis
Authors: Blanchette Robert A. , Sharon Edward M.
Published: May 2008

Agrobacteriumtumefaciens (E. F. Smith and Town.) Conn, was evaluated as a promoter of wound healing on mechanically inflicted basal wounds on 50 greenhouse-grown and 45 field-grown yellow birch, Betulaalleghaniensis Britt. Inoculated and noninoculated wounds were wrapped with a clear plastic wrap. The healing process of external wound closure by callus and internal compartmentalization of tissues extant before wounding was observed. Treated wounds showed a fourfold to fivefold increase in wound closure after 30 days for greenhouse-grown trees and after 45 days for field-grown trees. Effects of internal defense reactions that occur after injury were histologically examined. Compartmentalization of the wounded tissue was stimulated by treatment with A. tumefaciens. Abundant vessel plugging and an enhanced zone of cells, which formed after wounding, served to compartmentalize the wound. Although the effect of A. tumefaciens against antagonistic microorganisms is uncertain, the natural defense reactions of the tree were intensified while accelerating wound closure.
Microbial Respiration and Exchangeable Ammonium in Podzol Organic Horizon Materials Treated with Urea
Authors: Salonius Peter O. , Mahendrappa M. K.
Published: May 2008

Microbial activity was stimulated more in litter (L) and fermentation (F) than in humus (H) horizon materials by the addition of urea. Both pH and soluble carbon in water extracts were increased by urea treatment. Immobilization of nitrogen from the added urea was greatest in the L horizon materials followed in order by the materials from the F and H horizons. The relevance of these results to field practice is discussed.
Effects of thinning on biomass growth in young Populustremuloides plots
Authors: Hocker Jr. H. W.
Published: May 2008

Stem, branch, and leaf biomass and leaf-area index (LAI) were estimated for 4 years of growth in plots of thinned and unthinned 7-year-old Populustremuloides Michx. In 1978, transmitted photosynthetically active radiation (PAR) was monitored to estimate percent PAR transmitted. Four years after thinning total aboveground biomass and LAI in the thinned plots exceeded prethinning levels, but were still much less than in the unthinned plots. Leaf biomass and LAI in the unthinned plots increased to 3900 kg ha−1 and 5.7, respectively, but were still increasing in the thinned plots. Annual net stem and branch production during the study was relatively constant at about 5300 kg ha−1 year−1 in the unthinned plots, while net production in the thinned plots was still increasing. Transmitted PAR attenuated rapidly to LAI 3.5, approaching asymptote near LAI 5. Results suggest that, in the short term, thinning of young stands will decrease total aboveground biomass, but net annual biomass accumulation may not be greatly different between thinned and unthinned stands. LAI 3.5 may be an acceptable value for 11-year-old stands but should be permitted to increase to near LAI 5 in older stands.
Augmentation de la concentration des sédiments en suspension suite à l'exploitation forestière et durée de l'effet
Authors: Plamondon André P.
Published: May 2008

The concentration of inorganic and organic suspended sediments is analysed in seven streams subject to different cutting procedures. Skidding the logs across the streams maintains the concentration of the inorganic and organic fractions above 1000 and 500 mg/L, respectively, with maxima reaching 197 000 and 65 000 mg/L. The concentrations generally remain under 35 mg/L when the stream is protected by a buffer zone. This zone may be a strip of standing trees or a width of soil untouched by the skidders. Disturbances of small tributaries frequently increases the concentration levels in the main stream above 100 mg/L with maxima reaching 960 and 2030 mg/L for the inorganic and organic fractions, respectively. The supplementary input of particulate matter becomes negligible 1 year after logging, except in Linière stream. There is no direct relation between the width of the green strip and the input of suspended sediments. The best protective measure is the conservation of a buffer zone along all the watercourses. This strip of unperturbed soil should be about 10 to 15 m wide.
The relation between first-season bud morphology and second-season shoot morphology of jack pine seedlings
Authors: Kremer Antoine , Larson Philip R.
Published: May 2008

Seedlings of 20 open-pollinated families of Pinusbanksiana Lamb. from the Lake States region were grown the first season in two controlled environment rooms differing only in temperature. After a period of dormancy induction followed by a period of dormancy at low temperatures, all seedlings were grown a second season in a uniform greenhouse environment. Three bud types were recognized based on first-season bud dissections and confirmed by second-season shoot analyses. Type 1 buds consisted of a proximal zone of stem units bearing primary needles and a distal zone of stem units bearing scales. Type 2 buds, with a basal whorl of long-shoot primordia, were typical of 2-year-old buds. Type 3 buds were polycyclic. They were essentially a type 2 bud superimposed on a type 1 bud. Short-shoot activity was more prevalent in type 2 and 3 buds than on type 1 buds the first season suggesting that bud morphology may be established early during seedling development. Type 1 buds were unaffected by temperature, but the frequency of type 2 buds decreased and that of type 3 buds increased in the high compared with the low temperature environment. The frequency of type 1 and 2 buds differed among provenances; type 2 buds increased slightly from north to south within the study range. Significant differences in bud types were also found among the families examined.
Nitrate formation and movement before and after clear-cutting of a monitored watershed in central New Brunswick, Canada
Authors: Krause H. H.
Published: May 2008

A watershed of 391 ha, supporting tolerant hardwoods on elevated sloping portions and softwoods on low lying areas, was clear-cut in 1978. Nitrate nitrogen was monitored over 5 years before and 3 years after clear-cutting by periodic extraction of soil solution samples and continuous sampling of the brooks draining the cut and a similar control watershed. The brooks were gauged to determine water discharge. Before clear-cutting, nitrate nitrogen was not detectable for most of the time in soil solutions under softwood cover, but occurred commonly under hardwood cover with concentrations ranging upward to 4.7 mg/L. Nitrate nitrogen in the brooks varied from undetectable to 0.3 mg/L. After clear-cutting, nitrate nitrogen increased to maximum concentrations of 13.4 mg/L, in the soil solution under hardwood cover, and 1.6 mg/L, in the main channel of the brook. Soil solution nitrogen was not changed significantly by clear-cutting of softwood stands. The 3-year cumulative nitrogen loss attributable to clear-cutting was 19.1 kg/ha. Nitrate nitrogen in soil solutions, branch, and main stream indicated that disproportionately larger amounts of nitrogen were lost from the elevated and sloping portions of the watershed than from the lower lying areas.
Stabilité phénotypique de la croissance en hauteur et cinétique journalière de la pression de sève et de la transpiration chez le pin maritime (Pinuspinaster Ait.)
Authors: Guyon J. P. , Kremer A.
Published: May 2008

A study of geographic variation of maritime pine (Pinuspinaster Ait.) 9 years old, regarding height growth, transpiration and sap pressure daily kinetics has been performed in two sites, one in coastal sand dune and the other one in a more interior well-drained sandy moor. Successive height increments were measured from the 4th to the 9th year of growth and the year × provenance interaction was investigated. Transpiration and sap pressure were measured on 2-year-old needle fascicles. Results show discriminant variations between provenances and suggest some hypotheses about the possible ways of natural selection concerning drought resistance. The provenances North Landes (France) and Leiria (Portugal) grow best and strongly react to any variation of environmental factors as reflected by the high value of the slope of their regression lines (regression of their annual mean on the overall annual mean). Such a genotypie instability coincides with an intense physiologic activity (large flux of water correlated with a strong loss of weight by transpiration, reaching after 3 min 2% of the total dry weight of the separated needles and associated with the lowest sap pressure when the sun is around zenith). On the contrary, the Morocan provenance Tamjoute shows a large stability; its daily curves of transpiration and sap pressure reach early their maximum and minimum and therefore express a stress avoidance. Between these two extreme behaviours, the provenances Cazorla (south Spain) and Porto-Vecchio (Corsica) have intermediate values of transpiration and sap pressure, and their height growth shows a relative stability of response to environmental change.
Ultraviolet reflectance from tamarack (Larixlaricina (DuRoi) K. Koch) foliage
Authors: Feeney R. C. , Marshall P. E. , Olson Jr. C. E.
Published: May 2008

Examination of aerial, multispectral scanner images indicated that Larixlaricina (DuRoi) K. Koch foliage was much more reflective of ultraviolet light than was foliage of other woody species in the local area. This was confirmed in spectrophotometric studies. Young L. laricina needles reflected about 10% of incident ultraviolet light whereas foliage of 10 other woody species and 2 understory herbaceous species reflected less than 6%. The higher reflectivity of L. laricina needles was lost if cuticular waxes were removed from young needles or if needles were exposed to weathering for more than 2 months. The role of ultraviolet reflectivity is unclear, but the phenomenon may be a useful tool to identify L. laricina in multispectral images.
A new technique for estimating root system activity
Authors: Dunsworth B. G. , Kumi J. W.
Published: May 2008

A preliminary investigation of the use of mitotic indexing for quantifying root system activity in Pseudotsugamenziesii (Mirb.) Franco and Abiesamabilis (Dougl.) Forbes seedlings during the fall of 1981 indicated that the technique was sensitive enough to detect seasonal variability in both species.
A geometrical tree volume model based on the location of the centre of gravity of the bole
Authors: Forslund Robert R.
Published: May 2008

not available
Sulfur processing in forest soil and litter along an elevational and vegetative gradient
Authors: Watwood Mary E. , Fitzgerald John W. , Gosz James R.
Published: May 2008

O2 litter and A1 horizon soil samples from various locations within the Santa Fe and Cibola National Forests of New Mexico were assayed for sulfate adsorption, organic S formation, and organic S solubilization and mineralization (mobilization). During a 48-h incubation, samples of O2 litter were found to adsorb between 1.6 and 4.1 nmol g−1 of added sulfate S and to form 2.0 to 9.8 nmol g−1 of organic S from this anion. Between 17 and 48% of this organic S was mobilized within 24 h. A1 horizon soils adsorbed 1.2 to 4.9 nmol g−1 of added sulfate S and formed between 1.6 and 4.8 nmol g−1 of organic S during 48 h. Between 20 and 50% of this organic S was mobilized within 24 h. Estimations of S-accumulation potentials for both horizons were made from these determinations. Intrinsic S pools were quantified to determine the S status of the samples prior to incubation. Carbon-bonded forms of S were found to predominate in samples from both horizons, while ester sulfate accounted for most of the remaining S. Sample pH, moisture content, and total carbon content were also determined. Attempts were made to correlate these characteristics and S pool sizes with laboratory determined potentials for sulfate adsorption, organic S formation, and mobilization. For some sites, relationships were established between sulfate adsorption, soil pH, and total C, whereas the total S and organic S content of most samples agreed well with organic S formation potentials.
Effects of root zone temperature on root initiation and elongation in red pine seedlings
Authors: Andersen Chris P. , Sucoff Edward I. , Dixon Robert K.
Published: May 2008

The influence of root zone temperature on root initiation, root elongation, and soluble sugars in roots and shoots was investigated in a glasshouse using 2-0 red pine (Pinusresinosa Ait.) seedlings lifted from a northern Minnesota nursery. Seedlings were potted in a sandy loam soil and grown in chambers where root systems were maintained at 8, 12, 16, or 20 °C for 27 days; seedling shoots were exposed to ambient glasshouse conditions. Total new root length was positively correlated with soil temperature 14, 20, and 27 days after planting, with significantly more new root growth at 20 °C than at other temperatures. The greatest number of new roots occurred at 16 °C; the least, at 8 °C. Total soluble sugar concentrations in stem tissue decreased slightly as root temperature increased. Sugar concentrations in roots were similar at all temperatures. The results suggest that root elongation is suppressed more than root tip formation when red pine seedlings are exposed to the cool soil temperatures typically found during spring and fall outplanting.
The determinants of ocean freight costs for forest products
Authors: Wisdom Harold W. , Jones Kevin S.
Published: May 2008

A theoretical model is developed to demonstrate that product stowage, unit value, and competition are important determinants of ocean transportation costs, in addition to distance. Empirical estimates of the model are made to test whether the nondistance factors are of practical importance. The results indicate that they are. Although distance is an important determinant of transport cost, differences in competition can lead to significant differences in rates among routes of essentially the same distance. Product stowage and unit value are important determinants of differences in rates among products. Failure to recognize the influence of factors in addition to distance will distort trade-flow predictions. The distortion will be greatest in those cases where the trade model predicts significant changes in either domestic production or demand.
Nutrient, moisture, and light relations in 5-year-old Douglas-fir plantations under variable competition
Authors: Cole Elizabeth C. , Newton Michael
Published: May 2008

Competition for soil nutrients, moisture, and light was examined in 5-year-old plantations of young coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) growing at 17- to 123-cm spacings, alone or with either of two competitors, grass (Elymus spp. and Agrostistenuis L.) or red alder (Alnusrubra Bong.), on three different site types in the Oregon Coast Range. Douglas-fir foliar nitrogen concentration and total and available soil nitrogen did not differ significantly by competitor species; however, foliar phosphorus was higher in the grass treatments. Both foliar nitrogen and phosphorus concentrations were significantly lower at high planting densities. Predawn moisture stress varied with site, competitor, and density, the lowest stresses occurring at low densities where Douglas-fir was growing alone. Canopy light penetration varied with competitor, density, and height above ground, the lowest values occurring under the red alder canopy. Grass competed with Douglas-fir seedlings primarily for moisture until crown closure eliminated the grass. Nodulated red alder did not increase soil or Douglas-fir foliar nitrogen on any site or at any density, but competition from red alder trees reduced available light and moisture for Douglas-fir. Regardless of competitor type, high density resulted in increased demands on resources.
Vegetation composition on recent landslides in the Cascade Mountains of western Oregon
Authors: Miles D. W. R. , Swanson F. J.
Published: May 2008

Shallow, rapid landslides are common events and significant causes of vegetation disturbance in the Pacific Northwest. Landslides remove surface soil and above- and below-ground biomass from steep slopes and deposit them downslope or in streams. Vegetation cover and frequency were sampled on 25 landslides aged 6–28 years in the Cascade Mountains of western Oregon. Landslides sampled were debris avalanches ranging in surface area from 36 to 1287 m2, in elevation from 460 to 1100 m, and in slope from 40 to 173%. The landslides originated in undisturbed forests, recently harvested tracts of timber, road cuts, and road fills. Substrates within landslide areas were separated into five types and the vegetation cover was estimated for each: bedrock, 19%; secondary erosion, 25%; primary scar, 51%; secondary deposition, 57%; primary deposition, 71%. Vegetation cover averaged 51% overall and cover ranged from 7 to 88% among landslide sites. No relation between landslide age and vegetation cover was established. Pseudotsugamenziesii (Mirb.) Franco was the most common tree species overall and dominated all substrates except bedrock, where no single tree species occurred on more than 20% of the plots. Rubusursinus Cham. & Schlecht. was the most common shrub species on all substrates. Anaphalismargaritacea (L.) B & H and Trientalislatifolia Hook, were the most common herb species on all substrates except bedrock, where annual Epilobium spp. were most common.
The influence of time of precommercial thinning on the colonization of Douglas-fir by three species of root-colonizing insects
Authors: Witcosky J. J. , Schowalter T. D. , Hansen E. M.
Published: May 2008

In plantations of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in western Oregon, precommercial thinning resulted in significantly increased abundances of insect vectors of black-stain root disease. Hylastesnigrinus (Mann.), Pissodesfasciatus LeC, and Steremniuscarinatus (Boh.) were monitored for 2 years (1983 and 1984) in unthinned plots and in plots thinned in September 1982, January 1983, or May 1983. Abundances of these beetle species were significantly higher in thinned plots, relative to unthinned plots. However, the numbers of H. nigrinus and P. fasciatus caught by unbaited traps in plots thinned in May was reduced relative to plots thinned in September or January. These results suggest that time of thinning can be manipulated to reduce the activity of these vectors in plantations that are mechanically thinned.