bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence de la monensine sur la composition lipidique et protéique des culots membranaires chez Botrytis cinerea Pers. et Sclerotium rolfsii Sacc.
Authors: Koulali Yahya , Fonvieille Jean Louis , Es-Sgaouri Abbes , Dargent Robert
Published: April 2011

Membranes of young hyphae of Botrytis cinerea and Sclerotium rolfsii in the presence or absence of monensin were isolated and their chemical content was determined. Monensin induced a reduction of protein/lipid and sterol/phospholipid ratios. These modifications show that monensin affects vesicular traffic and also both the normal biosynthesis and growth.Key words: monensin, membranes, Botrytis cinerea, Sclerotium rolfsii.
Foliar fungal endophytes from two species of the mangrove Rhizophora
Authors: Suryanarayanan T S , Kumaresan V , Johnson J A
Published: April 2011

Endophytic fungi were isolated from leaves of Rhizophora apiculata Bl. and Rhizophora mucronata Lamk., two typical mangrove plants growing in the Pichavaram mangrove of Tamil Nadu, Southern India. Three hundred leaf segments from each plant species were sampled during dry and rainy months. More endophytes could be isolated during the rainy months than during the dry period. Hyphomycetes and sterile forms were more prevalent than ascomycetes or coelomycetes. Sporormiella minima, Acremonium sp. strain MG1 and a sterile fungus (MG90) were isolated from both plants irrespective of the season. Some endophytes were common to both plants, although a few appeared to be host specific. This is the first report on fungal endophytes in leaves of mangrove plants in India.Key words: endophytic fungi, Rhizophora apiculata, Rhizophora mucronata, mangrove, leaves.
The antimutagenic properties of a polysaccharide produced by Bifidobacterium longum and its cultured milk against some heterocyclic amines
Authors: Sreekumar O , Hosono A
Published: April 2011

The antimutagenicity and fermentation pattern of three Bifidobacterium longum strains (B. longum, B. longum PS+, and B. longum PS-) in skim milk were studied. The increase in fermentation time significantly increased antimutagenicity with all strains tested against the mutagenicity of both 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) in an Ames-like test using streptomycin-dependent strain SD510 of Salmonella typhimurium TA98. Bifidobacterium longum PS+, a polysaccharide-producing strain, had a longer lag phase but showed the highest inhibition percentage against both mutagens tested. The viability of B. longum PS+ cells was not affected by the low pH of 4.1, probably owing to the protection offered by the polysaccharide produced. The antimutagenicity of the fermented milk against Trp-P-1 was dose dependent. The strains were also able to bind with different amino acid pyrolysates, and B. longum showed the highest binding. Acetone extracts of fermented skim milk dissolved in water showed less antimutagenicity than extracts dissolved in dimethylsulfoxide. The isolated crude polysaccharide from B. longum PS+ showed a dose-dependent inhibition of the mutagenicity of Trp-P-1. Thus, we conclude that the polysaccharide of B. longum PS+ can be used as an antimutagen.Key words: Bifidobacterium longum, polysaccharides, fermented milk, heterocyclic amines.
Group-specific differentiation of Rhizobium from clover species by PCR amplification of 23S rDNA sequences
Authors: Tesfaye Mesfin , Holl F Brian
Published: April 2011

Two 20-bp primers that provide group-specific detection of Rhizobium spp. by polymerase chain reaction (PCR) have been used to differentiate strains that belong to different effectiveness groups within the Rhizobium-Trifolium cross-inoculation group. The target for DNA amplification was a 370-bp fragment of the 23S rDNA region. Analysis of additional root-nodule forming, as well as root-associated bacterial species by PCR-primer assay revealed that variability within this 20-bp segment of the 23S rDNA region may be widespread and provide an effective identification tool. Our data suggest that strains of Rhizobium isolated from the perennial clover Trifolium semipilosum may be phylogenetically more closely related to Rhizobium etli.Key words: Rhizobium, Trifolium, detection, PCR, rDNA.
Esterase activity and release of ethyl esters of medium-chain fatty acids by Saccharomyces cerevisiae during anaerobic growth
Authors: Bardi Laura , Crivelli Cristina , Marzona Mario
Published: April 2011

During anaerobic fermentation, Saccharomyces cerevisiae releases large amounts of medium-chain fatty acids (MCFAs) and related ethyl esters which are very important for aromatic quality of fermented beverages. The physiological function of ester synthesis is not yet understood. As MCFAs are toxic, their conversion to esters has been proposed to be a detoxification mechanism. Esterases possess ester synthesizing ability. Throughout an anaerobic fermentation of a lipid-free synthetic medium carried out with a S. cerevisiae strain selected for wine making, we have monitored MCFA and ethyl ester production and, at the same time, measured growth and esterasic activity of intact cells. Because no correlation was found between the concentration of each fatty acid and its ethyl ester, there is no evidence that ester synthesis reduces the toxicity of MCFAs. Esterasic activity did not show any correlation with ester synthesis, but it was related to the release of MCFAs. A model is proposed in which ester synthesis is a consequence of the arrest of lipid biosynthesis resulting from a lack of oxygen. Under these conditions, an excess of acyl coenzyme A is produced, and acyl esters are formed as secondary products of reactions aimed at recovering free coenzyme A.Key words: yeast, esterase, medium-chain fatty acids, toxicity, ethyl esters.
Cell extensions in pkc1 mutants of Saccharomyces cerevisiae
Authors: Azuma M , Torii S , Kato J , Ooshima H
Published: April 2011

To obtain information on cell wall synthesis and its relationship to morphology, we examined the induction of cell extensions of yeast upon the addition of isoamyl alcohol in osmotically fragile mutants that had mutations in genes related to the cell integrity pathway through activation of the mitogen-activated protein kinase cascade. We found that isoamyl alcohol induces cell extensions in pkc1 deletion mutants but not in mutants with mutations in genes positioned downstream or upstream of the PKC1 gene. These results suggest that Pkc1p functions not only in the integrity pathway but also in the induction. We characterized the elongated cells; many had two or more nuclei. We found no difference in cell surface structure between round and elongated cells from the results of chitin staining and cell wall extraction. Actin cytoskeleton was organized in elongated cells, as well as round cells. Cytochalasin D (0.08 mg/mL) inhibited the formation of actin cable but did not affect the induction of cell extensions.Key words: Saccharomyces cerevisiae, pkc1, isoamyl alcohol, cell extension.
Output scale, technical change, and productivity in the Canadian pulp and paper industry
Authors: Hailu Atakelty , Veeman Terrence S
Published: April 2011

Input distance function and index number methods are used to analyze productivity and efficiency in the Canadian pulp and paper industry. Productivity growth is decomposed into components that have different managerial and policy implications. The conventional productivity measures from the study are also compared with environmentally sensitive measures that take into account changes in pollutant outputs. The paper finds that most of the productivity growth indicated by index number methods is due to output scale effects rather than true productivity growth resulting from technical progress or improvements in the degree of productive efficiency. Researchers are advised to employ methods that allow for the identification of different productivity growth components. The results also show that conventional measures that ignore pollution abatement activities understate true productivity growth in the industry.
The influence of forest site on rate and extent of soil compaction and profile disturbance of skid trails during ground-based harvesting
Authors: Williamson J R , Neilsen W A
Published: April 2011

Soil compaction has been considered a principal form of damage associated with logging, restricting root growth and reducing productivity. The rate and extent of soil compaction on skid trails was measured at six field locations covering a range of dry and wet forests. Data was collected for up to 21 passes of a laden logging machine. A similar extent of compaction, averaging 0.17 g·cm-3 increase in total soil bulk density (BD), was recorded for all field sites despite substantial site and soil differences. On average, 62% of the compaction in the top 10 cm of the soil occurred after only one pass of a laden logging machine. The environment under which soils had formed played a major role in determining the BD of the undisturbed soil. Compaction was strongly related to the original BD, forest type, and soil parent material. Soil strengths obtained in the field fell below levels found to restrict root growth. However, reduction in macropores, and the effect of that on aeration and drainage could reduce tree growth. On the wettest soils logged, machine forces displaced topsoils rather than causing compaction in situ. Recommended logging methods and implications for the development of sustainability indices are discussed.
Seedling emergence of Pinus sylvestris in characterized seedbed substrates under different moisture conditions
Authors: Oleskog Gunilla , Grip Harald , Bergsten Urban , Sahlén Kenneth
Published: April 2011

Establishment of Scots pine (Pinus sylvestris L.) stands from seed is often unsuccessful because of unsuitable environmental conditions, such as limited soil moisture or air humidity. Improved seedling emergence could be achieved by soil preparation if site-specific optimal seedbeds were specified. Therefore the effects of seedbed substrates (13 characterized mixtures of sand, silt, and organic matter) on seedling emergence were determined after 14-day emergence tests in small laboratory chambers with four moisture conditions (2 levels of relative air humidity (RH), 95 and 65%, in combination with 2 levels of substrate water tension, 3 and 10 kPa). Seeds were placed in (partially buried) and on noncompacted and compacted substrates. At 95% RH, seedling emergence was 80 to 95% (seed lot maximum 94%) regardless of the substrate, with the exception of seeds placed in silt substrates (30-70%). At 65% RH, seedling emergence was 90% on silt, but considerably lower on organic matter and sand substrates, where organic admixture improved emergence for sand, but had a neutral or negative effect for silt. At 65% RH, partial seed burial, i.e., with good seed-substrate contact, improved emergence for organic matter and sand substrates, but impaired emergence for pure silt in noncompacted substrates at 3 kPa soil water tension. The effect of compaction on emergence was small for most substrates and had an effect only at 65% RH and 10 kPa tension. Seedling emergence and soil hydraulic conductivity at 3 kPa water tension and 95% RH were negatively correlated for partially buried seeds, but regardless of seed position, they were positively correlated at 10 kPa tension and 65% RH. These results can be used as guiding principles for the creation of seedbed substrates and seeding techniques.
Underplanted conifer seedling survival and growth in thinned Douglas-fir stands
Authors: Brandeis Thomas J , Newton Michael , Cole Elizabeth C
Published: April 2011

In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had been thinned to basal areas ranging from 16 to 31 m2/ha. Understory vegetation was treated with a broadcast herbicide application prior to thinning, a directed release herbicide application 2 years later, or no treatment beyond harvest disturbance. Residual overstory density was negatively correlated with percent survival for all four species. Broadcast herbicide application improved survival of grand fir and western hemlock. Western redcedar, grand fir, and western hemlock stem volumes were inversely related to overstory tree density, and this effect increased over time. There was a strong indication that this was also the case for Douglas-fir. Reduction of competing understory vegetation resulted in larger fourth-year stem volumes in grand fir and western hemlock.
Some physiological properties of Cryptomeria japonica leaves from Kanto, Japan: potential factors causing tree decline
Authors: Takamatsu T , Sase H , Takada J
Published: April 2011

Japanese cedar (Cryptomeria japonica D. Don) has been declining in urban areas of Japan. We examined if the decline was associated with physiological deterioration of leaves and resulting water stress. Leaves from three locations (severe decline, slight decline, and healthy) were analyzed for minimum transpiration rates (MT), amounts of epicuticular wax (EW), contact angles (CA), fractions of unhealthy stomata (US), cuticular thickness, and leaching of elements (LE). Anthropogenic elements (e.g., antimony (Sb)) in aerosols on the leaves were also analyzed by neutron activation analysis. MT, US, and amounts of Sb were 2, 15, and 10 times greater, respectively, at the severe decline location compared with the healthy location. LE was also greater at the severe decline location than at the slight decline and healthy locations. In contrast, CA was greatest at the healthy location and least at the severe decline location. MT correlated with the values obtained from a linear trinomial function that included EW, CA, and US as variables (r = 0.872, P < 0.01), and US correlated with amounts of Sb in aerosols (r = 0.939, P < 0.01). Therefore, it is likely that the deterioration of epicuticular wax and stomatal unhealthiness resulting mainly from clogging with aerosols, in combination with environmental aridification, have placed C. japonica under chronic and sometimes fatal water stress, causing tree decline.
Uncertainty in surface-fire history: the case of ponderosa pine forests in the western United States
Authors: Baker William L , Ehle Donna
Published: April 2011

Present understanding of fire ecology in forests subject to surface fires is based on fire-scar evidence. We present theory and empirical results that suggest that fire-history data have uncertainties and biases when used to estimate the population mean fire interval (FI) or other parameters of the fire regime. First, the population mean FI is difficult to estimate precisely because of unrecorded fires and can only be shown to lie in a broad range. Second, the interval between tree origin and first fire scar estimates a real fire-free interval that warrants inclusion in mean-FI calculations. Finally, inadequate sampling and targeting of multiple-scarred trees and high scar densities bias mean FIs toward shorter intervals. In ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the western United States, these uncertainties and biases suggest that reported mean FIs of 2-25 years significantly underestimate population mean FIs, which instead may be between 22 and 308 years. We suggest that uncertainty be explicitly stated in fire-history results by bracketing the range of possible population mean FIs. Research and improved methods may narrow the range, but there is no statistical or other method that can eliminate all uncertainty. Longer mean FIs in ponderosa pine forests suggest that (i) surface fire is still important, but less so in maintaining forest structure, and (ii) some dense patches of trees may have occurred in the pre-Euro-American landscape. Creation of low-density forest structure across all parts of ponderosa pine landscapes, particularly in valuable parks and reserves, is not supported by these results.
Seasonal root growth of Scots pine seedlings in relation to shoot phenology, carbohydrate status, and nutrient supply
Authors: Iivonen S , Rikala R , Vapaavuori E
Published: April 2011

To ascertain whether the growth rhythm of roots differs from that of the shoot, the seasonal pattern of dry mass allocation was determined in 1-year-old Scots pine (Pinus sylvestris L.) seedlings. Gas exchange, chlorophyll fluorescence, and the dynamics of starch and soluble sugars were examined to understand the role of stored carbon and that of current photosynthates in meeting the sink demand of plant organs. In this growth-chamber experiment, hydroponic cultures supplied the seedlings with low (0.25 mM N) or high (2.5 mM N) nutrient level. The climatic conditions in the chamber simulated the weather conditions from May to mid-October in southern Finland. Root growth was most intense at the end of the growing season, at which time shoot growth slowed down. Nutrient level did not affect the growth rhythm of the roots, but the total production of root biomass was favoured by high level of nutrients. The response of root growth to root zone temperature (RZT) was not the same over the growing season, indicating that the sensitivity of root growth to RZT depends on the growth phase of the seedling. The growth rhythm of the roots is probably regulated by several internal and external factors and their interactions, including RZT and availability of photosynthates.
Differences in needle morphology between blister rust resistant and susceptible western white pine stocks
Authors: Woo Kwan-Soo , Fins Lauren , McDonald Geral I , Wiese Maurice V
Published: April 2011

Needle traits were evaluated on three groups of western white pine (Pinus monticola Dougl.) seedlings: four open-pollinated families that ranked high for the "reduced needle lesion frequency" type of resistance to blister rust; four blister rust susceptible families; and two bulk lots from a seed orchard selected for blister rust resistance. No statistically significant differences were found for most traits in pairwise comparisons among the three groups. However, needles of susceptible families had significantly wider and larger stomata (greater area) than did those of resistant families and seed orchard lots; their stomata were also rounder (smaller ratio of stomatal length to width) than those of the seed orchard lots. Needles of the resistant stocks were significantly shorter than those from seed orchard bulks. Contact angles of water droplets on adaxial needle surfaces were also significantly larger on resistant families compared with the other genetic stocks. Results suggest the possibility of some threshold stomatal size and (or) critical stomatal shape related to infection by the blister rust fungus, Cronartium ribicola J.C. Fisch. ex Rabenh., and possible differences among the groups in wax chemistry and (or) surface textures, both of which may alter behavior of blister rust germ tubes and (or) be altered by blister rust infection.
Microorganisms Associated with Eutypellaparasitica in Acersaccharum and A. rubrum
Authors: Kliejunas J. T. , Kuntz J. E.
Published: April 2011

Many species of microorganisms were associated with Eutypellaparasitica in cankers on maple. The same species of microorganisms were present in noninoculated artificial branch and trunk wounds on maple trees and in natural wounds on sugar maple and red maple seedlings. There was little antagonistic effect of the associated microorganisms on growth of E. parasitica when paired in culture. Filtrates containing extracts of sugar maple outer bark saprophytes had no effect on spore germination or mycelial growth of E. parasitica. Isolations from branch stubs associated with natural cankers and from tissues in the trunk indicated that E. parasitica invaded tissues colonized first by other microorganisms.
Bales Versus Polybags in Cold and Frozen Overwinter Storage of Nursery Stock
Authors: Mullin R. E. , Parker J. D.
Published: April 2011

Fall lifted white spruce, white pine, and red pine were stored overwinter 1969–70 at Orono Nursery, Ontario. Frozen (−4 °C) and cold (1.5 °C) storage conditions; bales and polyethylene bags were compared. The trees were planted in the spring at three locations, both 'early' (May 5–8) and 'late' (May 26–28). This report is based on survival, height, and terminal shoot measurements to the end of the second season.Storage of white spruce was successful, the polybag was the better container, and frozen storage the better condition. White pine stored moderately successfully, and red pine storage was a failure.When planted late, fresh stock gave poor growth rates in all species. Reasonable extension of the planting season with frozen overwinter-stored stock appeared promising with white spruce. In white pine and red pine, however, late planting, even of stored stock, showed poor growth.
The Role of Free Growth in the Differentiation of Provenances of Black Spruce Piceamariana (Mill.) B.S.P.
Authors: Pollard D. F. W. , Logan K. T.
Published: April 2011

Two distinct phases of needle initiation contributed to the annual complement of needles of 4-year-old black spruce seedlings. The first phase occurred during development of the overwintering bud, and was expressed in predetermined growth. The second phase occurred in the same season as the overwintering bud was flushed, and was expressed in free growth. Ten black spruce provenances were flushed under conditions favorable or unfavorable for free growth. Variation in needle complements for overwintering buds was small and did not correlate with variation in height growth of provenances. Good correlation occurred between growth and needle complements when these included foliage initiated during any subsequent free growth. Fast growth of southern provenances grown at Chalk River, Ont. (46°00′N, 77°26′W), was interpreted as a result of less stringent requirements for free growth. Free growth potential was reduced or disappeared when the local photoperiod was shorter than that at the origin of the provenance. Free growth is characteristic of seedlings only, but advantages thus obtained by southern provenances in the first few years of growth probably establish lasting gains in height.
Some Effects of Stand Density on Biomass of Red Alder
Authors: Smith J. H.G. , DeBell D. S.
Published: April 2011

Stand density (degree of crowding of trees within stocked areas) was studied in relation to formation and yield of juvenile red alder (Alnusrubra Bong.) stands. Large variations in tree size and biomass of fully-stocked stands were associated with differences in stand density. Measurement of density in addition to stocking (the fraction of area occupied by trees) will improve biomass studies. It will also facilitate comparisons of biomass results with existing information from spacing studies and yield tables.
Floral Receptivity in American Elm
Authors: Lee Ming-Jen T. , Lester Donald T.
Published: April 2011

The pattern of floral receptivity as measured by production of viable seeds was illustrated through controlled pollinations at five stages of anthesis. Maximum viable seed was produced from pollinations made shortly before anther dehiscence.
Polyphenol Variation in Sitka Spruce
Authors: Forrest G. I.
Published: April 2011

The distribution of polyphenols in various tissues of Sitka spruce is described, with data on seasonal variation. Leaves were rich in a variety of flavonoids, but the main stem constituents were stilbenes. There was great variation both between and within provenances in most components, but evidence was obtained for differences in stilbene content attributable to provenance. Different temperature regimes caused marked differences in phenolic content, but clonal characteristics generally overrode treatment differences. High temperature favored polymeric polyphenol synthesis, while a lower temperature promoted high phenolic accumulations especially of monomeric components.
Extension and Longitudinal Growth During the Development of Red Pine Root Systems
Authors: Fayle D. C. F.
Published: April 2011

Extension of the root system and stem during the first 30 years of growth of plantation-grown red pine (Pinusresinosa Ait.) on four sites was deduced by root and stem analyses. Maximum rooting depth was reached in the first decade and maximum horizontal extension of roots was virtually complete between years 15 and 20. The main horizontal roots of red pine seldom exceed 11 m in length. Elongation of vertical and horizontal roots was examined in relation to moisture availability and some physical soil conditions. The changing relations within the tree in lineal dimensions and annual elongation of the roots and stem are illustrated. The development of intertree competition above and below ground is considered.
Influence de l'application de superphosphate et de K2SO4•MgSO4 avec l'urée à un humus de forêt de pin gris. II. Dissolution des matières humiques et rétention ionique
Authors: Carrier D. , Bernier B.
Published: April 2011

In an incubation experiment, the application of urea (224 kg N/ha) to jack pine (Pinusbanksiana Lamb.) raw humus resulted in significant amounts of water-soluble humic substances. When triple superphosphate (TSP: 48–192 kg P/ha) or potassium–magnesium sulphate (SPM: 198 kg K/ha) were applied with urea, the solubilization of humic substances was appreciably reduced. The retention of applied cations, particularly Ca and Mg, against water extraction from the humus was strongly enhanced when urea was applied with TSP and (or) SPM; TSP-phosphorous retention in the humus layer was also increased.
Resin disease: a new disease of lodgepole pine dwarf mistletoe
Authors: Mark Walter R. , Hawksworth Frank G. , Oshima Nagayoshi
Published: April 2011

A disease syndrome (termed resin disease) of Arceuthobiumamericanum on lodgepole pine is reported in Colorado, Idaho, Montana, Utah, and Wyoming. The disease effectively kills shoots from established dwarf mistletoe plants. In one area in Colorado, all of the dwarf mistletoe plants were diseased, and most of the aerial shoots were killed. Isolations from naturally infected resin disease cankers yielded 11 fungi; Alternariaalternata and Aureobasidiumpullulans were isolated most commonly. In inoculated dwarf mistletoe plants, Alternariaalternata was the most pathogenic, and it was followed closely by Aureobasidiumpullulans. Cladosporiumherbarum and Epicoccumnigrum may also play some role in disease development. Apparently, several weakly parasitic fungi can cause resin disease symptoms. A necrophylactic periderm was found in all naturally and artificially induced resin disease cankers examined and is presumably the mechanism by which dwarf mistletoe shoots are killed. The necrophylactic periderm isolates the shoots and cortical strands from the sinkers. Periderm formation apparently results from the invasion of the pine bark by the resin disease fungi.
Wood structure and production within the trunk and branches of Piceasitchensis in relation to canopy formation
Authors: Denne M. P.
Published: April 2011

The seasonal progress of wood production and variation in tracheid dimensions were followed systematically along the trunk and main branches of Piceasitchensis trees and analysed in relation to the distribution of light intensity and leaf weight as the canopy develops. The aim was to provide data towards building models to predict effects of management on within-tree patterns of wood production and structure. Tracheid production began earliest at the tips of branches towards the base of the crown; the data show that tracheid production in the main stem began earliest several internodes below the leader, its onset progressing faster and having a shorter distance to travel down the upper branches. Tracheid production appeared to cease simultaneously throughout the trunk in codominant trees; it ceased earlier in severely suppressed trees, which consequently produced little or no latewood.In the main stem, maximum ring width occurred at least one internode above that carrying maximum total leaf dry weight. Maximum rate of tracheid production occurred one or two internodes above those having maximum current leaf dry weight, several internodes above the maximum total leaf weight. In branches, rate of wood production was closely correlated with light intensity.The seasonal increase in wall thickness from early- to latewood occurred more rapidly as you progress down the main stem to below the crown in 16-year-old trees; hence, Mork latewood began progressively earlier lower down the stem; this pattern was not developed in the trunk of younger trees. In all branches, latewood began earlier at the base than at the tip, owing to a more rapid seasonal increase in wall thickness towards the branch base. Tracheid diameter increased from the leader down to midcrown. In branches, partial correlations suggest that tracheid diameter varied with light intensity at the tip but inversely with whorl number at the branch base.
The age structure of a striped maple population
Authors: Hibbs David E.
Published: April 2011

Cohort and population age structure analysis showed that, after the initially high mortality rates of the 1st year (87.5%), striped maple seedlings (Acerpensylvanicum L.) underwent practically no mortality until the age of 15. Annual mortality was up (3.8%) between the ages of 16 and 40, then dropped to a lower level (1.6%). Mortality was age dependent and generally density independent. The survivorship curve agrees well with a pattern that could be expected of a species whose strategy is gap phase replacement.
Note on the biology of Arceuthobiumpusillum
Authors: Baker Jr. Fred A. , French D. W.
Published: April 2011

Perennial aerial shoots of Arceuthobiumpusillum Peck with flabellate branching were found in Minnesota. Removal of aerial shoots, presumably by birds, from several dwarf mistletoe plants was also noted. Although rare in other host – dwarf mistletoe combinations, secondary infections are commonly found on black spruce (Piceamariana (Mill.) BSP).
Range-wide genetic variation of black spruce: reply
Authors: Morgenstern E. K.
Published: April 2011

not available
Seed input into a postfire forest site in northern Saskatchewan
Authors: Archibold O. W.
Published: April 2011

Seed traps were installed at seven sites along a transect in a burned mixedwood forest site in northern Saskatchewan to determine annual seed inputs. The seeds were returned to the laboratory for germination and identification. A total of 1698 seeds was collected in the 1977–1978 season, representing a seeding rate of 8.98 million seeds/ha. Epilobiumangustifolium L. was most abundant representing 63% of the total. Betulapapyrifera Marsh, accounted for 27.6% and Piceaglauca (Moench) Voss 6.1%. The seed count for 1978–1979 was 651 (3.44 million/ha) and represented a significant decline in herb and tree seeds.
Spatial aspects of sweetfern rust disease in northern Ontario jack pine – sweetfern stands
Authors: Gross Henry L. , Patton Robert F. , Ek Alan R.
Published: April 2011

In the jack pine – sweetfern stands of northern Ontario, jack pine (Pinusbanksiana Lamb.), sweetfern (Comptoniaperegrina [L.] Coult.), and portions of jack pine populations infected by the host-alternating sweetfern rust (Cronartiumcomptoniae Arth.) were shown to have aggregated spatial distributions. Competition with sweetfern and mortality caused by the disease affected the distribution of both jack pine and cankered jack pine. Proximity to sweetfern was the most important variable for rating the rust infection hazard. Hazard was greatest in patches of sweetfern and appeared to diminish beyond a distance of 12 m. Cankers were unusual at distances greater than 30 m. In young stands, cankered pine were concentrated in and near patches of sweetfern. In older stands the spatial character of cankered pines was a function of the percentage that survived the seedling stage, the distribution of the jack pine and sweetfern populations, and the amount of competition experienced by the cankered population.
Estimating phloem thickness in lodgepole pine stands using electrical resistance
Authors: Cole D. M. , Jensen C. E.
Published: April 2011

not available
Clonal variation in gross heat of combustion of juvenile Populus hybrids
Authors: Sastry C. B. R. , Anderson H. W.
Published: April 2011

Gross heat of combustion using an oxygen bomb calorimeter at ovendry condition was determined and analyzed for 2-year-old sprouts of 10 hybrid Populus L. clones of diverse genetic background. Values showed a clonal range of 14% from a low of 4357 cal g−1 (1 cal = 4.1868 J) to a high of 4955 cal g−1. Clones of section Aigeiros Duby (cottonwood) showed significantly greater energy potential than representatives of section Leuce Duby (aspens). There was a significant interaction of clones × sprouts indicating environmental conditions or manner of growth may influence the magnitude of clonal differences. No relationship was found between potential energy and stem specific gravity.Sample discs from a 5-year-old P. tremuloides stem and an 8-year-old P. × euramericana cl. DN-30 were also analyzed by individual growth rings. No relationship was found with density. Outer bark (rhytidome) showed higher calorific values than inner bark (secondary phloem). The possible implication in breeding poplars for energy production is discussed.
Young-growth western hemlock stand infection by Heterobasidionannosum 11 yearsm after precommercial thinning
Authors: Chavez Jr. T. D. , Edmonds R. L. , Driver C. H.
Published: April 2011

Infection level and course of spread of Heterobasidionannosum (Fr.) Bref, in a 26-year-old western hemlock(Tsugaheterophylla (Raf.) Sarg.) stand, precommercially thinned 11 years previously, was determined. Impact of infection on height and radial growth of western hemlock was also examined. Tree infection increased from a mean of 8% initially, to an average of 90% in the residual trees. Stump colonization accounted for 61% of the tree infection by H.annosum, with stumps within 61 cm of the remaining trees providing most of the inoculum. The fungus also entered through animal damage wounds. Growth rate of H. annosum was estimated at 75 cm/year with a range of 23–128 cm/year. Although there was no significant difference between infected and uninfected trees in height or radial growth, infected trees had less height and slightly more radial growth than uninfected trees.
A modeling strategy for the growth projection of managed stands
Authors: Arney James D.
Published: April 2011

Using a large data base of permanent research plots in coastal Douglas-fir, a growth projection strategy is developed. The emphasis is on stratifying growth influences into potential and modifier functions for components of diameter and height growth within a stand table. Growth periods are defined as equal increments of top height through time. The model developed is an individual-tree, distance-independent, stand-projection model.
Crown scorch volume and scorch height: estimates of postfire tree condition
Authors: Peterson David L.
Published: April 2011

In salvage operations after wildfire, timber managers need to identify those trees most likely to die. Crown scorch volume and scorch height are commonly used to estimate damage to conifers after fire. Calculated crown scorch volume based on scorch height and tree dimensions was compared with observed crown scorch volume for four common conifer species of the northern Rocky Mountains. Calculated crown scorch volume was significantly greater than observed crown scorch volume for all species. The overestimates are the result of differences among species and trees of varying crown shape. When postfire tree condition was evaluated from observed crown scorch volume rather than from measured scorch height, crown damage was estimated with greater accuracy. Functions that estimate postfire tree mortality based on crown damage should be based on observed crown scorch volume rather than scorch height.
Shoot morphology and growth pattern in seedlings of Pinusbrutia provenances
Authors: Calamassi Roberto , Falusi Mauro , Mugnai Laura
Published: April 2011

The process of primary growth in 2-year-old seedlings of six Pinusbrutia Ten. provenances is described. At the end of the first growing season, two types of shoot morphology were observed: type 1, a terminal winter bud, and type 2, a terminal rosette of primary needles protecting the meristematic apex. During the 2nd year the seedlings exhibited a succession of shoots (varying in number from one to five), each of which was due to the elongation of a new apical bud. Morphological observations along with an anatomical examination of the winter bud led to the conclusion that the growth pattern in juvenile P. brutia is monocyclic with a variable number of summer shoots (using the terminology proposed by Lanner (Lanner, R.M. 1976. In Tree physiology and yield improvement. Editedby M.G.R. Cannell and F.T. Last. Academic Press, London, pp. 223-243)). The provenances studied differed both in growth potential and in seasonal growth pattern (differences in number of shoots, ratio of spring shoot to total growth, growth rate). Two groups could be identified: (i) the provenances of the island of Crete, which had a low growth potential and short growing season, and (ii) the high-altitude provenances of inland Turkey, with high growth potential and a growth rate that peaked in summer.
Bud and shoot development in Piceaengelmannii in response to cone induction treatments
Authors: Owens John N. , Simpson Sheila J.
Published: April 2011

Apical size, mitotic index and developmental anatomy, and lateral shoot mitotic index and cell elongation were assessed in potted ramets of Piceaengelmannii (Parry) under seven cone-induction treatments using various combinations of drought, heat, and gibberellin A4/7. In control trees lateral shoot elongation resulted primarily from cell divisions before vegetative bud flush and cell elongation following bud flush. The most rapid phase of shoot elongation occurred as the mitotic index decreased and cell elongation increased. The best cone induction occurred with treatments that retarded apical mitotic index and shifted the time of apical differentiation until lateral shoot elongation was completed or nearly completed. Most terminal apices resumed development when heat and gibberellin A4/7 treatments ended, but a few remained latent. There is a complex relationship among apical development, elongation of the subtending shoot, and reproductive bud differentiation that is not considered in most cone-induction treatments and often leads to quite variable results even within a species.
Stomatal conductance in three conifer species at different elevations during summer in Wyoming
Authors: Carter Gregory A. , Smith William K. , Hadley Julian L.
Published: April 2011

Stomatal conductances to water vapor diffusion in Engelmann spruce (Piceaengelmannii Parry ex Engelm.), subalpine fir (Abieslasiocarpa (Hook.) Nutt.), and lodgepole pine (Pinuscontorta Engelm.) were compared to determine environmental influences on conductance at higher (3220 m) and lower (2860 m) elevations in the central Rocky Mountains. Measurements were taken on clear days, and soil water potentials remained at or greater than −0.1 MPa. Interspecific differences were small between spruce and fir at either site, but pine conductance was generally higher than spruce or fir at 2860 m. Daily maximum conductance in spruce and fir at 3220 m did not increase above 1.0 mm s−1 until daily minimum air temperature (early morning) increased to near 1 °C in early summer. Increases in maximum conductance above 2.0 mm s−1 occurred at both elevations when minimum air temperature rose above approximately 5 °C. At the lower elevation site, increases in maximum conductance during late July and mid-August appeared to depend strongly on soil temperature increasing above 7–8 °C. The persistence of cold soil temperatures in the highest elevations of the subalpine forest may serve to inhibit stomatal opening in spruce and fir in comparison to spruce, fir, and pine in lower elevation forests.
Cyclophytic effects on wood structure in Pinus radiata D. Don. I. Densitometry and grain angle
Authors: Dodd Richard S. , Walker Nancy K.
Published: April 2011

Wood structural characteristics were compared in 11-year-old Pinusradiata trees from hedge- and tree-form donors (H and T) to examine the effects of apical ageing (cyclophysis) on wood formation. Although the differences were small, T plants tended to produce wood with narrower growth rings and lower density in the first two rings. T plants showed a greater contrast between density at the end of one growth ring and the beginning of the next. The lower mean growth ring density in T plants was mainly due to a lower earlywood density with little difference in latewood density or latewood percentage. Although differences in density from early- to late-wood were greater in T plants, there was no difference between H and T plants in within-ring density variation. This was due to greater fluctuations in density across growth rings of H plants, perhaps because these plants were less buffered against the environment. Differences in wood structure between H and T plants were not the same for all clones, as shown by significant interactions in the analyses of variance. These different responses may have resulted from differences in the effectiveness of hedging in slowing apical maturation, or from differences in rates of maturation.
Blowdown and stand development in a Colorado subalpine forest
Authors: Veblen Thomas T. , Hadley Keith S. , Reid Marion S. , Rebertus Alan J.
Published: April 2011

Stand development of a subalpine forest in the Colorado Front Range following a ca. 15-ha blowdown was examined by analyzing tree population age structures and radial growth patterns. The stand studied was initiated by a fire at the start of the 18th century and was dominated by a dense population of lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) at the time of blowdown in 1973. Before the blowdown, the subcanopy was characterized by abundant subalpine fir (Abieslasiocarpa (Hook.) Nutt.) and scarce Engelmann spruce (Piceaengelmannii (Parry) Engelm.). Comparison with an adjacent control stand, affected only slightly by the blowdown, indicates that new seedling establishment following the blowdown was slight. Instead, the response was dominated by the release of the subcanopy fir and spruce, resulting in acceleration of the successional replacement of lodgepole pine by these shade-tolerant species. Given the >300 years required for an old-growth fir and spruce stand to develop following catastrophic fire, the likelihood of a major canopy disturbance in the form of blowdown and (or) lethal insect attack is high and should be explicitly incorporated into general explanations of stand development of subalpine forests in the southern Rocky Mountains.
Differences in composition and release rate of volatiles emitted by black spruce seed cones sampled in situ versus ex situ
Authors: Turgeon Jean J , Brockerhoff Eckehard G , Lombardo Domenic A , MacDonald Linda , Grant Gary G
Published: April 2011

The volatile emissions of black spruce (Picea mariana (Mill.) BSP) seed cones still attached to a live 7 m tall tree (in situ) were compared with those of cones from the same tree that had been severed (ex situ). Volatiles were collected simultaneously with a manifold headspace sampling system, adsorbed on Porapak® Q, and the extracts analysed by capillary gas chromatography (GC) and GC - mass spectrometry. The relative abundance of the identified constituents, tricyclene, alpha- and beta-pinene, camphene, sabinene, beta-myrcene, DELTA-3-carene, p-cymene, beta-phellandrene, limonene, gamma-terpinene, alpha-terpinolene, camphor, borneol, and bornyl acetate differed quantitatively, almost qualitatively, between in situ and ex situ samples. For example, camphene and bornyl acetate represented ca. 7% and 12% of total emissions, respectively, of the volatiles from in situ cones and ca. 0.9% and <0.2%, respectively, of the volatiles from ex situ cones. beta-phellandrene and beta-pinene were consistently less abundant in extracts of in situ collections (ca. 4.5% and 22%, respectively) than in those of ex situ collections (ca. 6% and 32%, respectively). Also, the release rate of total monoterpenes from in situ seed cones was approximately twice as high as that from ex situ cones. These results indicate that ex situ sampling does not accurately depict the composition of volatile emissions by seed cones and suggest that tests for biological activity based on such compositions could lead to erroneous conclusions.
Changes in properties of epicuticular wax and the related water loss in Japanese cedar (Cryptomeria japonica) affected by anthropogenic environmental factors
Authors: Sase Hiroyuki , Takamatsu Takejiro , Yoshida Tomio , Inubushi Kazuyuki
Published: April 2011

The leaves of Cryptomeria japonica D. Don collected near an electrochemical plant (on Yakushima Island) had more wax (approximately 10% higher in 1-year leaves) and less chlorophyll (approximately 50 and 30% lower in 0- and 1-year leaves, respectively) than those from a reference area, although the trees showed no symptoms of decline. In the Kanto Plain around Tokyo (Saitama and Ibaraki), where C. japonica is declining (dieback and (or) defoliation), the amount of epicuticular wax in current-year leaves and the leaf chlorophyll content were almost equivalent to those of healthy plants in mountainous areas, but the wax eroded more rapidly (approximately 1.5 times faster). Although the C and O contents and the C/O ratio of epicuticular wax were approximately equivalent irrespective of the levels of decline, the cuticular transpiration rate, especially in 1-year leaves, was higher in Saitama (water loss: 0.92 ± 0.21%/h) and to some extent in Ibaraki (0.66 ± 0.08%/h) than in the mountainous area (0.60 ± 0.12%/h). This excessive transpiration, probably resulting from a degraded wax layer and the partial malfunctioning of stomata due to deposited aerosols, may be a significant factor causing the decline of C. japonica. Dry atmospheric conditions (e.g., rain factor <100), which have prevailed since the 1950s due to urbanization, may have inflicted additional stress on the tree.
A comparison of economic impact assessment methods: the case of forestry developments in Alberta
Authors: Alavalapati Janaki RR , Adamowicz Wiktor L , White William A
Published: April 2011

Economic impacts of forestry developments in Alberta are estimated using two interindustry approaches. The results suggest that estimates derived from input-output (I-O) models differ from those of computable general equilibrium (CGE) models. Employment and GDP estimates derived from CGE models are much smaller than those of I-O models. Unlike I-O estimates, estimates derived from CGE models are not unidirectional because of general equilibrium effects. The results also indicate that CGE models provide greater flexibility and have more potential for forest policy analysis when compared with I-O models, but they should be used with caution.