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Sample records for european larch larix

  1. Larix P. Mill.: larch

    Treesearch

    Raymond C. Shearer

    2008-01-01

    The larches - Larix P. Mill. - of the world are usually grouped into 10 species that are widely distributed over much of the mountainous, cooler regions of the Northern Hemisphere (Hora 1981; Krussmann 1985; Ostenfeld and Larsen 1930; Rehder 1940; Schmidt 1995). Some species dominate at the northern limits of boreal forests and others occur above subalpine forests (...

  2. The folivore guild on larch (Larix decidua) in the alps

    Treesearch

    W. Baltensweiler

    1991-01-01

    The term "guild" describes a group of organisms that exploit the same class of resources in a similar manner (Root 1967, Mattson et al. 1988). This study focuses on six members of the folivore guild of subalpine larch, Larix deciduas, in Switzerland--five lepidopterans and one hymenopteran. From 1949 to 1979, Auer (1977) sampled populations...

  3. Carbon dioxide exchange of larch (Larix gmelinii) cones during development.

    PubMed

    Wang, Wenjie; Zu, Yuangang; Cui, Song; Hirano, Takashi; Watanabe, Yoko; Koike, Takayoshi

    2006-10-01

    Larch (Larix gmelinii (Rupr.) Rupr.) cone scales are green, but little is known of their photosynthetic role in cone development or about how they differ in gas exchange characteristics from needle leaves. In contrast to leaf photosynthesis (Pleaf), we found that stomatal regulation of cone photosynthetic rate (Pcone) was marginal because the photosynthetic carbon came from internal recycling of respiratory carbon dioxide (CO2). Photosynthetic recycling of respired CO2 was confirmed by the finding that the intercellular CO2 concentration (Ci) in cone scales was much higher than ambient [CO2]; also, there was a positive correlation between Pcone and Ci, whereas Pleaf was almost constant as Ci varied. Low chlorophyll (Chl) concentration was a limiting factor for Pcone, but not for Pleaf, as indicated by the correlation between Pcone and chlorophyll concentration. Moreover, chlorophyll utilization efficiency (Psat/Chl a+b) for cone scales was lower than that for leaves. In both cones and leaves, nitrogen (N) was positively correlated with photosynthetic capacity (P), but the P/N value was much lower for cones than for leaves. For both organs, the ratio of respiration to N was broadly similar. Although mature cones have no photosynthetic capacity, Pcone of young cones was as high as 5.3 micromol m(-2) s(-1), about 1.26 times the value of Pleaf, and accounted for the refixation of 30-40% of the respiratory CO2 produced by cones, equivalent to the photosynthetic capacity of a bundle of short shoots near each cone. Thus, Pcone may be an important additional source of photosynthate for cones, given the weak assimilating capacity of leaves that are not fully expanded during cone development.

  4. Pathogenicity of the pinewood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings

    PubMed Central

    Mamiya, Y.; Shoji, T.

    2009-01-01

    Pathogenicity of the pine wood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings was tested with inoculation experiments under nursery conditions. Water suspensions of nematodes (mixed stages cultured on Botrytis cinerea or dispersal fourth-stage juveniles (DJ4) extracted from the adult Japanese pine sawyer, Monochamus alternatus) were injected into the stems of 2- and 3-year-old Japanese larch and Japanese black pine, Pinus thunbergii, seedlings growing in a nursery. In another treatment, Japanese pine sawyer adults holding DJ4 were released under a net that covered the upper half of the seedlings. Regardless of nematode inoculation method, Japanese larch seedlings were as susceptible as Japanese black pine seedlings to B. xylophilus under nursery conditions. The rate of disease development was similar on larch and pine seedlings. Nematode population densities were lower in the stems of dead larch seedlings than in the stems of dead pine seedlings. Histopathological observations revealed that the distribution of nematodes in the stems of dead larch seedlings was mostly limited to the cortex, phloem and cambial zone. Traumatic resin canal formation was one of the most characteristic symptoms in larch seedlings which was dissimilar to that in pine seedlings. PMID:22661789

  5. Pathogenicity of the pinewood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings.

    PubMed

    Mamiya, Y; Shoji, T

    2009-06-01

    Pathogenicity of the pine wood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings was tested with inoculation experiments under nursery conditions. Water suspensions of nematodes (mixed stages cultured on Botrytis cinerea or dispersal fourth-stage juveniles (DJ4) extracted from the adult Japanese pine sawyer, Monochamus alternatus) were injected into the stems of 2- and 3-year-old Japanese larch and Japanese black pine, Pinus thunbergii, seedlings growing in a nursery. In another treatment, Japanese pine sawyer adults holding DJ4 were released under a net that covered the upper half of the seedlings. Regardless of nematode inoculation method, Japanese larch seedlings were as susceptible as Japanese black pine seedlings to B. xylophilus under nursery conditions. The rate of disease development was similar on larch and pine seedlings. Nematode population densities were lower in the stems of dead larch seedlings than in the stems of dead pine seedlings. Histopathological observations revealed that the distribution of nematodes in the stems of dead larch seedlings was mostly limited to the cortex, phloem and cambial zone. Traumatic resin canal formation was one of the most characteristic symptoms in larch seedlings which was dissimilar to that in pine seedlings.

  6. Assessing mortality and regeneration of larch (Larix laricina) after a 1999-2004 landscape level outbreak of the larch sawfly (Pristiphora erichsonii) in Alaska (Project WC-EM-08-03)

    Treesearch

    Roger Burnside; Mark Schultz; Nicholas Lisuzzo; James Kruse

    2013-01-01

    Larch sawfly (LSF) (Pristiphora erichsonii) is an invasive defoliator in Alaska. Based on aerial survey data, this insect has impacted an estimated 600,000 to 700,000 acres of eastern larch (Larix laricina) stands in Alaska during a 6-year period between 1999 and 2004. Mortality of larch within the sawfly-defoliated area was 80 percent or more (...

  7. Hybrid larch (Larix x eurolepis Henry): a good candidate for cadmium phytoremediation?

    PubMed

    Moudouma, Chris Fabien Moussavou; Riou, Catherine; Gloaguen, Vincent; Saladin, Gaëlle

    2013-03-01

    Studies related to phytoremediation by conifers are still at their beginning. Thus, we investigated the ability of a hybrid larch (Larix x eurolepis) to accumulate cadmium (Cd). One-month-old clonal plantlets grown in vitro were exposed for 1 week to a high Cd concentration (1.5 mM). No significant effect was observed on root and shoot biomass, root length, and needle number as a result of Cd treatment. Leaf photosynthetic pigment content and total soluble protein concentration in roots and shoots remained unchanged compared to control plantlets. Taken together, these results suggested that hybrid larch tolerated Cd in our conditions. The high Cd concentration in shoots (200 μg Cd gram(-1) dry weight) showed the good capacity of larch to translocate Cd and thus a potential use of this species for phytoremediation. Furthermore, under our conditions, phytochelatin biosynthesis pathway was slightly stimulated, suggesting that this pathway did not reach the threshold and/or another mechanism of Cd storage may be involved to explain larch tolerance to Cd.

  8. Structure and Composition of Natural Gmelin Larch (Larix gmelinii var. gmelinii) Forests in Response to Spatial Climatic Changes

    PubMed Central

    Zhang, Jingli; Zhou, Yong; Zhou, Guangsheng; Xiao, Chunwang

    2013-01-01

    Background Many theoretical researches predicted that the larch species would decrease drastically in China under future climatic changes. However, responses of the structural and compositional changes of Gmelin larch (Larix gmelinii var. gmelinii) forests to climatic changes have rarely been reported. Methodology/Principal Findings Field survey was conducted to examine the structures and compositions of natural Gmelin larch forests along a climatic gradient. Stepwise linear regression analyses incorporating linear and quadratic components of climatic and non-climatic factors were performed on the structural and compositional attributes of those natural Gmelin larch forests. Isothermality, Max Temperature of Warmest Month (TempWarmestMonth), Precipitation of Wettest Month (PrecipWettestMonth), Precipitation Seasonality (PrecipSeasonality) and Precipitation of Driest Quarter (PrecipDriestQuarter) were observed to be effective climatic factors in controlling structure and composition of Gmelin larch forests. Isothermality significantly affected total basal area of larch, while TempWarmestMonth, PrecipWettestMonth and PrecipSeasonality significantly affected total basal area of Mongolian pine, and PrecipDriestQuarter significantly affected mean DBH of larch, stand density of larch and total basal area of spruce and fir. Conclusions/Significance The summer and winter temperatures and precipitations are all predicted to increase in future in Northeast China. Our results showed the increase of total basal area of spruce and fir, the suppression of regeneration and the decrease of stand density of larch under increased winter precipitation, and the decrease of total basal area of larch under increased summer temperature in the region of current Gmelin larch forest. Therefore, we suggest that larch would decrease and spruce and fir would increase in the region of future Gmelin larch forest. PMID:23824710

  9. Container volume and growing density influence western larch (Larix occidentalis Nutt.) seedling development during nursery culture and establishment

    Treesearch

    Matthew M. Aghai; Jeremiah R. Pinto; Anthony S. Davis

    2014-01-01

    Larch tree species (Larix Mill.) are both ecologically and commercially valuable in their native range and are the focus of many restoration, afforestation, and commercial reforestation efforts in the boreal forests of the northern hemisphere. Land use change, shifting climate, and poor natural regeneration are making it increasingly difficult to establish the species...

  10. Cajander larch (Larix cajanderi) biomass distribution, fire regime and post-fire recovery in northeastern Siberia

    NASA Astrophysics Data System (ADS)

    Berner, L. T.; Beck, P. S. A.; Loranty, M. M.; Alexander, H. D.; Mack, M. C.; Goetz, S. J.

    2012-06-01

    Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes, and post-disturbance ecosystem recovery. Our primary objective here was to analyze post-fire accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated ca. 1969-2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≥ 25 yr, 271 ± 26 g m-2, n=66 [mean ± SE]) and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33-38 yr, 746 ± 100 g m-2, n=32), though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr-1 × 104 km-2 than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr-1 × 104 km-2. The MODIS burned area maps underestimated the total area burned in this region from 2000-2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery were strongly associated (r2≍0

  11. Cajander larch (Larix cajanderi) biomass distribution, fire regime and post-fire recovery in northeastern Siberia

    NASA Astrophysics Data System (ADS)

    Berner, L. T.; Beck, P. S. A.; Loranty, M. M.; Alexander, H. D.; Mack, M. C.; Goetz, S. J.

    2012-10-01

    Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes and post-disturbance ecosystem recovery. Our primary objective here was to analyse post-fire accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated c. 1966-2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≤ 25 yr, 271 ± 26 g m-2, n = 66 [mean ± SE]) and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33-38 yr, 746 ± 100 g m-2, n = 32), though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr-1 × 104 km-2) than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr-1 × 104 km-2). The MODIS burned area maps underestimated the total area burned in this region from 2000-2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery were strongly associated (r2 ≈ 0

  12. 76 FR 52543 - European Larch Canker; Expansion of Regulated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... (44 U.S.C. 3501 et seq.). List of Subjects in 7 CFR Part 301 Agricultural commodities, Plant diseases... disease caused by a fungus that can kill mature and immature species of the genus Larix (larch) and... and around the regulated areas. Since APHIS established the ELC regulations, Maine's survey data have...

  13. Screening larch in vitro for resistance to Mycosphaerella laricina

    Treesearch

    M.E. Ostry; Paula M. Pijut; D.D. Skilling

    1991-01-01

    Needle blight of larch caused by Mycosphaerella laricina seriously limits the productivity of susceptible trees in the north central and northeastern United States. Adventitious shoots, derived from cotyledon tissue culture, of selected European larch (Larix decidua) and a hybrid larch were inoculated in vitro with three isolates...

  14. Neural cell activation by phenolic compounds from the Siberian larch (Larix sibirica).

    PubMed

    Loers, Gabriele; Yashunsky, Dmitry V; Nifantiev, Nikolay E; Schachner, Melitta

    2014-07-25

    Small organic phenolic compounds from natural sources have attracted increasing attention due to their potential to ameliorate the serious consequences of acute and chronic traumata of the mammalian nervous system. In this contribution, it is reported that phenols from the knot zones of Siberian larch (Larix sibirica) wood, namely, the antioxidant flavonoid (+)-dihydroquercetin (1) and the lignans (-)-secoisolariciresinol (2) and (+)-isolariciresinol (3), affect migration and outgrowth of neurites/processes from cultured neurons and glial cells of embryonic and early postnatal mice. Compounds 1-3, which were available in preparative amounts, enhanced neurite outgrowth from cerebellar granule neurons, dorsal root ganglion neurons, and motoneurons, as well as process formation of Schwann cells in a dose-dependent manner in the low nanomolar range. Migration of cultured astrocytes was inhibited by 1-3, and migration of neurons out of cerebellar explants was enhanced by 1. These observations provide evidence for the neuroactive features of these phenolic compounds in enhancing the beneficial properties of neurons and reducing the inhibitory properties of activated astrocytes in an in vitro setting and encourage the further investigation of these effects in vivo, in animal models of acute and chronic neurological diseases.

  15. Late-Holocene Expansion of Eastern Larch ( Larix laricina[Du Roi] K. Koch) in Northwestern Québec

    NASA Astrophysics Data System (ADS)

    Peñalba, M. Cristina; Payette, Serge

    1997-07-01

    The Holocene expansion of eastern larch ( Larix laricina[Du Roi] K. Koch) at the edge of its geographical range in northwestern Québec was reconstructed using pollen and macrofossils from peat deposits. Because Larixis a poor pollen producer, the total pollen sum of 300-500 grains per spectrum was supplied by an additional survey of 2000 grains. However, the use of 2000 pollen counts did not give a better Larixrecord. The combination of both pollen and macrofossil analyses offered greater opportunities to estimate the time of arrival of eastern larch at the edge of its distributional range. Along the study transect, eastern larch established east of 75° W long before 2000 yr B.P. but not sooner than 5000 yr B.P., whereas it arrived much later, after 1500 yr B.P., in most sites west of 75° W within a migration corridor around 57° 45' N. The macrofossil record is completely different between the eastern sites, with high frequencies and densities, and the western sites where larch occurs sporadically with few remains only, concentrated in the upper part of the peat profiles. The colonization pattern of eastern larch was patchy in time and space, as suggested by the available macrofossil records, present distributional pattern in the area, and age structure of extant populations. The establishment of disjunct larch populations in the westernmost sites most likely proceeded from long-distance transport. The spatial-temporal pattern of eastern larch west of 74° W may have been influenced by the site conditions associated with late deglaciation in central northern Québec.

  16. Monoterpene emissions from needles of hybrid larch F1 (Larix gmelinii var. japonica × Larix kaempferi) grown under elevated carbon dioxide and ozone

    NASA Astrophysics Data System (ADS)

    Mochizuki, Tomoki; Watanabe, Makoto; Koike, Takayoshi; Tani, Akira

    2017-01-01

    We measured monoterpene emissions from needles of hybrid larch F1 (Larix gmelinii var. japonica × Larix kaempferi) to evaluate the response of monoterpene emission rates and their composition to elevated CO2 (600 μmol mol-1) and O3 (60 nmol mol-1) conditions. The dominant monoterpenes were α-pinene and β-pinene. The emission rate of total monoterpenes significantly decreased under elevated CO2 conditions (P < 0.05). The ratio of carbon emission in the form of monoterpenes to photosynthetically fixed carbon also significantly decreased under elevated CO2 conditions. By contrast, elevated O3 did not significantly affect the emission rate of total monoterpenes. The ratios of α-pinene/β-pinene, limonene/β-pinene, and myrcene/β-pinene were all significantly decreased by O3 exposure (P < 0.05). High reactivity of α-pinene, limonene, and myrcene when combining with O3 may be able to mitigate oxidative damage inside the larch needles. No significant combined effects of elevated CO2 and O3 on individual or total monoterpene emissions were detected.

  17. Expression patterns of LmAP2L1 and LmAP2L2 encoding two-APETALA2 domain proteins during somatic embryogenesis and germination of hybrid larch (Larix x marschlinsii).

    PubMed

    Guillaumot, Damien; Lelu-Walter, Marie-Anne; Germot, Agnès; Meytraud, Fanny; Gastinel, Louis; Riou-Khamlichi, Catherine

    2008-06-16

    Two APETALA2 domain transcription factors were characterized first in angiosperms, and, recently, in several gymnosperms. These proteins are involved in several processes, from flowering to embryogenesis in Arabidopsis thaliana. We extrapolated this result to hybrid larch (Larixxmarschlinsii Coaz) resulting from a cross between European (Larix decidua) and Japanese (Larix kaempferi) larches. Somatic embryogenesis is well described and controlled for this Pinaceae. We characterized two-AP2 domain genes: LmAP2L1 and LmAP2L2. Phylogenetic analysis confirmed that LmAP2L1 and LmAP2L2 were orthologous to Norway spruce PaAP2L1 and PaAP2L2 and that L1 forms appeared to be specific to Pinaceae. RT-PCR analysis showed that larch APETALA2 was differentially expressed during late somatic embryogenesis and during the first steps of germination. Whereas LmAP2L2 was constitutively expressed during this process, LmAP2L1 expression appeared only during late somatic embryogenesis, when embryos were able to germinate. Further, LmAP2L1 appeared to be the preferentially expressed form during embryo germination. Thus, LmAP2L1 seems to be a valuable molecular marker for hybrid larch late somatic embryogenesis and could play a role during post-embryonic development.

  18. Physiological responses of the hybrid larch (Larix × eurolepis Henry) to cadmium exposure and distribution of cadmium in plantlets.

    PubMed

    Bonet, Amandine; Lelu-Walter, Marie-Anne; Faugeron, Céline; Gloaguen, Vincent; Saladin, Gaëlle

    2016-05-01

    Phytoextraction of Cd is a growing biotechnology although we currently know few Cd hyperaccumulators, i.e., plant species able to accumulate at least 0.1 mg Cd g(-1) dry weight in aerial organs. Owing their deep root system and high biomass, trees are more and more preferred to herbaceous species for phytoextraction. Assuming that conifers could be relevant models under cold climates, we investigated cadmium tolerance of the hybrid larch Larix × eurolepis Henry (Larix decidua × Larix kaempferi) and the efficiency of this species to store this metal. In vitro grown larches were chosen in order to reduce time of exposure and to more rapidly evaluate their potential efficiency to accumulate Cd. One-month-old plantlets were exposed for 2 and 4 weeks to 250 and 500 μM Cd. Results showed that they tolerated a 4-week exposure to 250 μM Cd, whereas the content of photosynthetic pigment strongly dropped in plantlets growing in the presence of 500 μM Cd. In the presence of 250 μM Cd, shoot growth slightly decreased but photosynthetic pigment and total soluble carbohydrate contents were not modified and no lipid peroxidation was detected. In addition, these plantlets accumulated proline, particularly in shoots (two to three times more than control). In roots, Cd concentration in the intracellular fraction was always higher than in the cell wall fraction contrary to shoots where Cd concentration in the cell wall fraction increased with time and Cd concentration in the medium. In shoots, Cd concentration was lower than in roots with a ratio of 0.2 after 4 weeks of exposure but stayed around 0.2 mg g(-1) dry weight, thus a value higher than the threshold requested for Cd hyperaccumulators. Hybrid larch would thus be a relevant candidate for field test of Cd phytoextraction.

  19. Herbicide Trials on European Larch in Northern Wisconsin

    Treesearch

    Daniel A. Netzer

    1984-01-01

    Herbicides of 17 different rates and formulations were oversprayed on newly planted 1-0 European larch seedlings in teh spring of 1983 at the recommended rates. Simazine, bifenox, oxyfluorfen, promamide, and oryzalin provided adequate weed control with no damage to the larch. Height growth at the end of the first growing season was one-and-a-half times greater in the...

  20. Soil respiration of the Dahurian Larch (Larix gmelinii) forest and the response to fire disturbance in Da Xing'an Mountains, China

    Treesearch

    Tongxin Hu; Long Sun; Haiqing Hu; David R. Weise; Futao Guo

    2017-01-01

    Despite the high frequency of wildfire disturbances in boreal forests in China, the effects of wildfires on soil respiration are not yet well understood. We examined the effects of fire severity on the soil respiration rate (Rs) and its component change in a Dahurian Larch (Larix gmelinii) in Northeast China. The results showed...

  1. Ecological indicators of forest degradation after forest fire and clear-cutting in the Siberian larch (Larix sibirica) stand of Mongolia

    Treesearch

    Y.D. Park; D.K. Lee; J.A. Stanturf; S.Y. Woo; D. Zoyo

    2009-01-01

    This study was conducted to investigate ecological indicators of forest degradation after forest fire and clear-cutting in the Siberian larch (Larix sibirica Ledeb.) stand of Mongolia. The species abundance and biodiversity indices were higher in burned and clear-cut stands than those of reference stand, but boreal understory species, such as Vaccinium vitis-idaea,...

  2. SR-XRFA in Biogeochemical Studies: Elemental Composition of Larch Tissues (Larix cajanderi Mayr.) of the Kuranakh Gold ore Field (Russia, Yakutia)

    NASA Astrophysics Data System (ADS)

    Artamonova, Svetlana Yu.; Zhuravskaya, Alla N.

    Technogenic impact on the elemental composition of larch (Larix cajanderi Mayr.) in the Kuranakh Gold ore field (Russia, Yakutia) is considered. Elemental composition of the larch tissues was determined by means of X-ray fluorescence measurements with synchrotron radiation at the "Siberian Synchrotron and Terahertz Radiation Center" based on VEPP-3 of the Budker Institute of Nuclear Physics SB RAS. Comprehensive possibilities of the X-ray fluorescence measurements along with the simple preparation of biological samples, allowed us to carry out valuable biogeochemical studies. New data on the accumulation of macroelements K, Ca, Mn, Fe, biophilic microelements Cu, Zn, chalcophilous Mo, Pb, Ag, As, Sb, Ga, Cd, Tl, rare lithophilous Rb, Sr, Zr, Y, Nb, in the tissues of larch (Larix cajanderi Mayr.) of the natural taiga landscape and the tailing dump in the Kuranakh Gold ore field were obtained. The results allow us to assess both natural and technogenic biogeochemical anomalous aureole of gold mining areas.

  3. Polysaccharide arabinogalactan from larch Larix sibirica as carrier for molecules of salicylic and acetylsalicylic acid: preparation, physicochemical and pharmacological study.

    PubMed

    Chistyachenko, Yulia S; Dushkin, Alexandr V; Polyakov, Nikolay E; Khvostov, Mikhail V; Tolstikova, Tatyana G; Tolstikov, Genrikh A; Lyakhov, Nikolay Z

    2015-05-01

    Inclusion complexes of salicylic acid (SA) and acetylsalicylic acid (aspirin, ASA) with polysaccharide arabinogalactan (AG) from larch wood Larix sibirica and Larix gmelinii were synthesized using mechanochemical technology. In the present study, we have investigated physicochemical properties of the synthesized complexes in solid state and in aqueous solutions as well as their anti-aggregation and ulcerogenic activity. The evidence of the complexes formation was obtained by nuclear magnetic resonance (NMR) relaxation technique. It was shown that in aqueous solution the molecules of SA and ASA are in fast exchange between the complex with AG macromolecules and solution. The stability constant of aspirin complex was calculated. It was shown that mechanochemically synthesized complexes are more stable when compared to the complex obtained by mixing solutions of the components. Complexes of ASA show two-fold increase of anti-platelet effect. It allows to reduce the dose of the antithrombotic drug and its ulcerogenic activity. These results substantiate the possibility to design new preparations on the basis of ASA with increased activity and safety.

  4. Larch (Larix kaempferi) xylem parenchyma cells respond to subfreezing temperature by deep supercooling.

    PubMed

    Kasuga, Jun; Takata, Naoki; Yamane, Kenichi; Kuroda, Katsushi; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    In previous studies, xylem parenchyma cells (XPCs) in the boreal softwood species larch, which has thick and rigid walls similar to those of XPCs in boreal hardwood species, were shown to respond to subfreezing temperature by deep supercooling during summer but change their freezing behavior to extracellular freezing during winter. In this study, we re-examined freezing behavior of XPCs in larch by observation of deep etching of frozen samples as well as observation of re-warmed samples after freezing using a cryo-scanning electron microscope. The results showed that XPCs in larch adapts to subfreezing temperature by deep supercooling throughout all seasons. Such freezing behavior is the same as that of XPCs in boreal hardwood species.

  5. Stratification requirements for germination of western larch (Larix occidentalis Nutt.) seed.

    Treesearch

    Frank C. Sorenson

    1990-01-01

    A northeast Washington collection of western larch seeds was stratified for 0,10, 20, 40, and 80 days and incubated at 55, 64, and 73 °F. The germination percentage of filled seeds and speed and uniformity of germination were improved by long stratification, particularly at the lowest incubation temperature. Stratified seeds were also nursery sown in early April and...

  6. In vivo assessment of an industrial waste product as a feed additive in dairy cows: Effects of larch (Larix decidua L.) sawdust on blood parameters and milk composition.

    PubMed

    Tedesco, D; Garavaglia, L; Spagnuolo, M S; Pferschy-Wenzig, E M; Bauer, R; Franz, C

    2015-12-01

    When larch (Larix spp.) is processed in the wood industry, the sawdust is currently disposed of as waste or used as combustible material, even though it is rich in biologically active compounds. In this study the effect of larch sawdust supplementation on blood parameters as well as milk composition was examined in healthy mid-lactating dairy cows. Twenty-four multiparous Italian Friesian dairy cows were assigned to groups receiving either 300 g/day/cow of larch sawdust or a control diet, and treatments were continued for a 20 day period. Milk parameters were unaffected by treatment. A lower plasma total protein concentration was observed and can be attributed to a decrease in globulin concentration. A lower plasma urea concentration was also detected in the larch group. Moreover, biomarkers of liver function were influenced by the treatment. Total bilirubin was lower in larch-treated animals, and cholesterol tended to be lower. In addition, an interaction between day and treatment was observed for very low density lipoprotein. The concentration of other parameters, including reactive oxygen metabolites, superoxide dismutase, glutathione peroxidase and nitrotyrosine, did not differ between treatments. The observed benefits, together with the good palatability, make larch sawdust a promising candidate for the development of beneficial feed supplements for livestock. Further studies will be useful, particularly to evaluate its efficacy in different health conditions.

  7. Larch Dwarf Mistletoe (FIDL)

    Treesearch

    Jerome S. Beatty; Gregory M. Filip; Robert L. Mathiason

    1997-01-01

    Larch dwarf mistletoe (Arceuthobium laricis (Piper) St. John) is a common and damaging parasite of western larch (Larix occidentalis Nutt.) in the Pacific Northwest and southern British Columbia. Larch dwarf mistletoe occurs commonly throughout the range of western larch in British Columbia, northern and central Idaho, western Montana and east of the Cascades in...

  8. 76 FR 81359 - European Larch Canker; Expansion of Regulated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ...), Lachnellula willkommi (Dasycypha), is a serious plant disease caused by a fungus that can kill mature and... Agricultural commodities, Plant diseases and pests, Quarantine, Reporting and recordkeeping requirements... Animal and Plant Health Inspection Service 7 CFR Part 301 European Larch Canker; Expansion of Regulated...

  9. Timing and duration of European larch growing season along altitudinal gradients in the Swiss Alps.

    PubMed

    Moser, Lea; Fonti, Patrick; Büntgen, Ulf; Esper, Jan; Luterbacher, Jürg; Franzen, Julia; Frank, David

    2010-02-01

    The 2007 European larch (Larix decidua Mill.) growing season was monitored along two elevational transects in the Lötschental valley in the Swiss Alps. Phenological observations and weekly microcore sampling of 28 larch trees were conducted between April and October 2007 at seven study sites regularly spaced from 1350 to 2150 m a.s.l. on northwest- and southeast-facing slopes. The developmental stages of nearly 75,000 individual cells assessed on 1200 thin sections were used to investigate the links between the trees' thermal regimes and growth phases including the beginning and ending of cell enlargement, wall thickening and maturation of the stem wood. Needles appeared approximately 3-4 weeks earlier than stem growth. The duration of ring formation lasted from mid-May to the end of October, with the length of the growing season decreasing along elevation from 137 to 101 days. The onset of the different growing seasons changed by 3-4 days per 100 m elevation; the ending of the growing season, however, appeared minimally related to altitude. If associated with the monitored altitudinal lapse rate of -0.5 degrees C per 100 m, these results translate into a lengthening of the growing season by approximately 7 days per degree Celsius. This study provides new data on the timing and duration of basic growth processes and contributes to quantification of the impacts of global warming on tree growth and productivity.

  10. Gene expression associated with increased supercooling capability in xylem parenchyma cells of larch (Larix kaempferi).

    PubMed

    Takata, Naoki; Kasuga, Jun; Takezawa, Daisuke; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    Xylem parenchyma cells (XPCs) in larch adapt to subfreezing temperatures by deep supercooling, while cortical parenchyma cells (CPCs) undergo extracellular freezing. The temperature limits of supercooling in XPCs changed seasonally from -30 degrees C during summer to -60 degrees C during winter as measured by freezing resistance. Artificial deacclimation of larch twigs collected in winter reduced the supercooling capability from -60 degrees C to -30 degrees C. As an approach to clarify the mechanisms underlying the change in supercooling capability of larch XPCs, genes expressed in association with increased supercooling capability were examined. By differential screening and differential display analysis, 30 genes were found to be expressed in association with increased supercooling capability in XPCs. These 30 genes were categorized into several groups according to their functions: signal transduction factors, metabolic enzymes, late embryogenesis abundant proteins, heat shock proteins, protein synthesis and chromatin constructed proteins, defence response proteins, membrane transporters, metal-binding proteins, and functionally unknown proteins. All of these genes were expressed most abundantly during winter, and their expression was reduced or disappeared during summer. The expression of all of the genes was significantly reduced or disappeared with deacclimation of winter twigs. Interestingly, all but one of the genes were expressed more abundantly in the xylem than in the cortex. Eleven of the 30 genes were thought to be novel cold-induced genes. The results suggest that change in the supercooling capability of XPCs is associated with expression of genes, including genes whose functions have not been identified, and also indicate that gene products that have been thought to play a role in dehydration tolerance by extracellular freezing also have a function by deep supercooling.

  11. Southern montane populations did not contribute to the recolonization of West Siberian Plain by Siberian larch (Larix sibirica): a range-wide analysis of cytoplasmic markers.

    PubMed

    Semerikov, Vladimir L; Semerikova, Svetlana A; Polezhaeva, Maria A; Kosintsev, Pavel A; Lascoux, Martin

    2013-10-01

    While many species were confined to southern latitudes during the last glaciations, there has lately been mounting evidence that some of the most cold-tolerant species were actually able to survive close to the ice sheets. The contribution of these higher latitude outposts to the main recolonization thrust remains, however, untested. In the present study, we use the first range-wide survey of genetic diversity at cytoplasmic markers in Siberian larch (Larix sibirica; four mitochondrial (mt) DNA loci and five chloroplast (cp) DNA SSR loci) to (i) assess the relative contributions of southern and central areas to the current L. sibirica distribution range; and (ii) date the last major population expansion in both L. sibirica and adjacent Larix species. The geographic distribution of cpDNA variation was uninformative, but that of mitotypes clearly indicates that the southernmost populations, located in Mongolia and the Tien-Shan and Sayan Mountain ranges, had a very limited contribution to the current populations of the central and northern parts of the range. It also suggests that the contribution of the high latitude cryptic refugia was geographically limited and that most of the current West Siberian Plain larch populations likely originated in the foothills of the Sayan Mountains. Interestingly, the main population expansion detected through Approximate Bayesian Computation (ABC) in all four larch species investigated here pre-dates the LGM, with a mode in a range of 220,000-1,340,000 years BP. Hence, L. sibirica, like other major conifer species of the boreal forest, was strongly affected by climatic events pre-dating the Last Glacial Maximum.

  12. The Effect of Soil Manganese on Japanese Larch (Larix Leptolepis Sieb. and Zucc.) Seedlings in the Greenhouse

    Treesearch

    Callie Jo Schweitzer; William E. Sharpe; Pamela J. Edwards

    1999-01-01

    Preliminary analysis of 9 year old Japanese larch trees and soil subjected to appliitions of triple ambient annual nitrogen (N) and sulfur (S) deposftfon revealed elevated available soil and foliar manganese (Mn) levels and decreased growth compared to controls. A greenhouse study was conducted in which Japanese larch seedlings were grown in geld collected soil...

  13. Genetic variation, phenotypic stability, and repeatability of drought response in European larch throughout 50 years in a common garden experiment

    PubMed Central

    George, Jan-Peter; Grabner, Michael; Karanitsch-Ackerl, Sandra; Mayer, Konrad; Weißenbacher, Lambert; Schueler, Silvio

    2017-01-01

    Abstract Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degree of genetic determination in a 50-year-old common garden experiment in the drought-prone northeastern Austria. Tree ring data from larch provenances originating from across the species' natural range were used to estimate the drought reaction in four consecutive drought events (1977, 1981, 1990–1994, and 2003) with extremely low standardized precipitation- and evapotranspiration-index values that affected growth in all provenances. We found significant differences among provenances across the four drought periods for the trees’ capacity to withstand drought (resistance) and for their capacity to reach pre-drought growth levels after drought (resilience). Provenances from the species' northern distribution limit in the Polish lowlands were found to be more drought resistant and showed higher stability across all drought periods than provenances from mountainous habitats at the southern fringe. The degree of genetic determination, as estimated by the repeatability, ranged up to 0.39, but significantly differed among provenances, indicating varying degrees of natural selection at the provenance origin. Generally, the relationship between the provenances’ source climate and drought behavior was weak, suggesting that the contrasting patterns of drought response are a result of both genetic divergence out of different refugial lineages and local adaptation to summer or winter drought conditions. Our analysis suggests that European larch posseses high genetic variation among and within provenances that can be used for assisted migration and breeding programs. PMID

  14. Genetic variation, phenotypic stability, and repeatability of drought response in European larch throughout 50 years in a common garden experiment.

    PubMed

    George, Jan-Peter; Grabner, Michael; Karanitsch-Ackerl, Sandra; Mayer, Konrad; Weißenbacher, Lambert; Schueler, Silvio

    2016-09-26

    Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degree of genetic determination in a 50-year-old common garden experiment in the drought-prone northeastern Austria. Tree ring data from larch provenances originating from across the species' natural range were used to estimate the drought reaction in four consecutive drought events (1977, 1981, 1990-1994, and 2003) with extremely low standardized precipitation- and evapotranspiration-index values that affected growth in all provenances. We found significant differences among provenances across the four drought periods for the trees' capacity to withstand drought (resistance) and for their capacity to reach pre-drought growth levels after drought (resilience). Provenances from the species' northern distribution limit in the Polish lowlands were found to be more drought resistant and showed higher stability across all drought periods than provenances from mountainous habitats at the southern fringe. The degree of genetic determination, as estimated by the repeatability, ranged up to 0.39, but significantly differed among provenances, indicating varying degrees of natural selection at the provenance origin. Generally, the relationship between the provenances' source climate and drought behavior was weak, suggesting that the contrasting patterns of drought response are a result of both genetic divergence out of different refugial lineages and local adaptation to summer or winter drought conditions. Our analysis suggests that European larch posseses high genetic variation among and within provenances that can be used for assisted migration and breeding programs.

  15. Genetic variation, phenotypic stability, and repeatability of drought response in European larch throughout 50 years in a common garden experiment.

    PubMed

    George, Jan-Peter; Grabner, Michael; Karanitsch-Ackerl, Sandra; Mayer, Konrad; Weißenbacher, Lambert; Schueler, Silvio; Mäkelä, Annikki

    2017-01-31

    Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degree of genetic determination in a 50-year-old common garden experiment in the drought-prone northeastern Austria. Tree ring data from larch provenances originating from across the species' natural range were used to estimate the drought reaction in four consecutive drought events (1977, 1981, 1990–1994, and 2003) with extremely low standardized precipitation- and evapotranspiration-index values that affected growth in all provenances. We found significant differences among provenances across the four drought periods for the trees’ capacity to withstand drought (resistance) and for their capacity to reach pre-drought growth levels after drought (resilience). Provenances from the species' northern distribution limit in the Polish lowlands were found to be more drought resistant and showed higher stability across all drought periods than provenances from mountainous habitats at the southern fringe. The degree of genetic determination, as estimated by the repeatability, ranged up to 0.39, but significantly differed among provenances, indicating varying degrees of natural selection at the provenance origin. Generally, the relationship between the provenances’ source climate and drought behavior was weak, suggesting that the contrasting patterns of drought response are a result of both genetic divergence out of different refugial lineages and local adaptation to summer or winter drought conditions. Our analysis suggests that European larch posseses high genetic variation among and within provenances that can be used for assisted migration and breeding programs.

  16. Plasticity in gas-exchange physiology of mature Scots pine and European larch drive short- and long-term adjustments to changes in water availability.

    PubMed

    Feichtinger, Linda M; Siegwolf, Rolf T W; Gessler, Arthur; Buchmann, Nina; Lévesque, Mathieu; Rigling, Andreas

    2017-09-01

    Adjustment mechanisms of trees to changes in soil-water availability over long periods are poorly understood, but crucial to improve estimates of forest development in a changing climate. We compared mature trees of Scots pine (Pinus sylvestris) and European larch (Larix decidua) growing along water-permeable channels (irrigated) and under natural conditions (control) at three sites in inner-Alpine dry valleys. At two sites, the irrigation had been stopped in the 1980s. We combined measurements of basal area increment (BAI), tree height and gas-exchange physiology (Δ(13) C) for the period 1970-2009. At one site, the Δ(13) C of irrigated pine trees was higher than that of the control in all years, while at the other sites, it differed in pine and larch only in years with dry climatic conditions. During the first decade after the sudden change in water availability, the BAI and Δ(13) C of originally irrigated pine and larch trees decreased instantly, but subsequently reached higher levels than those of the control by 2009 (15 years afterwards). We found a high plasticity in the gas-exchange physiology of pine and larch and site-specific responses to changes in water availability. Our study highlights the ability of trees to adjust to new conditions, thus showing high resilience. © 2017 John Wiley & Sons Ltd.

  17. Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

    NASA Astrophysics Data System (ADS)

    Petrillo, Marta; Cherubini, Paolo; Fravolini, Giulia; Marchetti, Marco; Ascher-Jenull, Judith; Schärer, Michael; Synal, Hans-Arno; Bertoldi, Daniela; Camin, Federica; Larcher, Roberto; Egli, Markus

    2016-03-01

    100 years in larch CWD. Consequently, the decay of Picea abies and Larix decidua is very low. Several uncertainties, however, remain: 14C dating of CWD from decay classes 4 and 5 and having a pre-bomb age is often difficult (large age range due to methodological constraints) and fall rates of both European larch and Norway spruce are missing.

  18. An iTRAQ-Based Proteomics Approach to Clarify the Molecular Physiology of Somatic Embryo Development in Prince Rupprecht's Larch (Larix principis-rupprechtii Mayr)

    PubMed Central

    Zhao, Jian; Li, Hui; Fu, Shuangbin; Chen, Bo; Sun, Wenting; Zhang, Junqi; Zhang, Jinfeng

    2015-01-01

    Prince Rupprecht's larch (Larix principis-rupprechtii Mayr) is a native high-value forest tree species in North China whose clonal propagation through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. To date, research has focused on clarifying the molecular mechanism of SE, but proteomic studies are still in the early stages. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) analysis was performed on three developmental stages of SE in L. principis-rupprechtii in an attempt to identify a wide range of proteins that are regulated differentially during this process. Proteins were extracted and analyzed from the pro-embryogenic mass (PEM), globular embryo (GE), and cotyledon embryo (CE) stages of embryo development. We detected 503 proteins in total and identified 96 proteins expressed differentially during different developmental stages. The identified proteins were analyzed further to provide information about their expression patterns and functions during SE. Four clusters of proteins based on shared expression profiles were generated. Functional analysis showed that proteins involved in primary metabolism, phosphorylation, and oxidation reduction were upregulated during somatic embryo development. This work provides novel insights into the process of larch embryo development in vitro and a basis for further study of the biological process and opportunities for practical application of this knowledge. PMID:25781987

  19. Release and retention patterns of organic compounds and nutrients after the cold period in foliar litterfall of pure European larch, common beech and red oak plantations in Lithuania

    NASA Astrophysics Data System (ADS)

    Čiuldienė, D.; Aleinikovienė, J.; Muraškienė, M.; Marozas, V.; Armolaitis, K.

    2017-01-01

    This study was carried out in alien warmth-tolerant forest plantations of red oak ( Quercus rubra), common beech ( Fagus sylvatica) and European larch ( Larix decidua). We compared the changes in foliar litterfall mass and biochemical composition after five months of cold period. The mean mass of fresh foliar litterfall collected in late autumn was 30% higher in red oak compared to the larch and beech plantations. After the cold period, the reduction of foliar litterfall mass did not exceed 10% in any of the studied plantations. The fresh foliar litterfall of red oak was the richest in cellular fibre and easily decomposable glucose and nutrients such as P and Mg, larch was distinguished by the highest lignin, N, K and Ca concentrations, while beech fresh foliar litterfall was the poorest in the aforementioned nutrients. After the cold period, the changes in the biochemical composition of foliar litterfall revealed different patterns. In the spring, the beech and red oak foliar litterfall was the richest in N, P and Ca, meanwhile the larch foliar litterfall still had the highest concentration of lignin but, in contrast to the autumn, was the poorest in nutrients. After the cold period Lignin: N, C: N and C: P ratios reached critical values indicating that the foliar litterfall of beech and red oak had started to decompose. The highest lignin concentration and the highest and most stable Lignin: N, C: N, C: P and N: P ratios after the cold period indicated that the slowest foliar litterfall decomposition took place in the larch plantation.

  20. Growth and Hydrologic Influence of European Larch and Red Pine 10 Years After Planting

    Treesearch

    Alfred Ray Harris; Richard S. Sartz

    1972-01-01

    Ten years after planting, European larch and red pine diameters averaged 11.2 and 9.6 cm, and heights averaged 9.7 and 5.1 m. Litter on the larch plots was twice as heavy as on the pine and unplanted conrtol plots. Organic carbon content of the top 5 cm of soil appeared to reflect vegetation differences, but soil bulk density did not. The amount of water depleted by...

  1. Within-Range Translocations and Their Consequences in European Larch

    PubMed Central

    Wagner, Stefanie; Liepelt, Sascha; Gerber, Sophie; Petit, Rémy J.

    2015-01-01

    In contrast to biological invasions, translocations of individuals within a species range are understudied, due to difficulties in systematically detecting them. This results in limited knowledge about the corresponding processes and uncertainties regarding the status of extant populations. European larch, a forest tree whose fragmented native distribution is restricted to the Alps and to other Central European mountains, has been massively planted for at least 300 years. Here we focus on the genetic characterization of translocations having taken place within its native range. Microsatellite variation at 13 nuclear loci and sequence data of two mitochondrial DNA fragments were analyzed on the basis of a comprehensive range-wide population sample. Two complementary methods (Geneclass and Structure) were used to infer translocation events based on nuclear data whereas mitochondrial data were used for validation of these inferences. Using Geneclass, we found translocation events in a majority of populations. Additional cases of translocation and many instances of admixture were identified using Structure, thanks to the clear-cut ancestral genetic structure detected in this species. In particular, a strong divide between Alpine and Central European populations, also apparent at mitochondrial markers, helped uncover details on translocation events and related processes. Translocations and associated admixture events were found to be heterogeneously distributed across the species range, with a particularly high frequency in Central Europe. Furthermore, translocations frequently involved multiple geographic sources, some of which were over-represented. Our study illustrates the importance of range-wide investigations for tracing translocations back to their origins and for revealing some of their consequences. It provides some first clues for developing suitable conservation and management strategies. PMID:26000791

  2. Identification of a novel factor, vanillyl benzyl ether, which inhibits somatic embryogenesis of Japanese larch (Larix leptolepis Gordon).

    PubMed

    Umehara, Mikihisa; Ogita, Shinjiro; Sasamoto, Hamako; Koshino, Hiroyuki; Asami, Tadao; Fujioka, Shozo; Yoshida, Shigeo; Kamada, Hiroshi

    2005-03-01

    In contrast to angiosperms, some gymnosperms form well-developed suspensors in somatic embryogenesis. This characteristic makes it easy to study suspensor biology. In cultures with high cell densities, somatic embryogenesis of Japanese larch, especially the suspensor development, is strongly inhibited due to factor(s) that are released by the cells into the culture medium. In this study, we purified and identified one of the inhibitory factors present in high-cell-density conditioned medium (HCM) of larch cells. The factor with the strongest inhibitory activity was purified by dialysis, extraction by ethyl acetate, octadecylsilyl (ODS) column chromatography and high-performance liquid chromatography (HPLC). The inhibitory factor was identified as vanillyl benzyl ether (VBE) by physicochemical analysis. This compound was first isolated from natural resources. Authentic VBE inhibited somatic embryo formation in Japanese larch, and the inhibitory effect in the suspensor was stronger than in the embryo proper. Furthermore, quantification of VBE by HPLC demonstrated that VBE accumulates at high concentrations in HCM. These results suggest that VBE is a novel negative regulator of somatic embryogenesis.

  3. Monitoring climate-driven interannual variability of European Larch phenology in an alpine environment: results of the REPHLEX project

    NASA Astrophysics Data System (ADS)

    Busetto, L.; Migliavacca, M.; Cremonese, E.; Colombo, R.; Galvagno, M.; Morra di Cella, U.; Pari, E.; Siniscalco, C.

    2009-04-01

    In this contribute we present the results of the REPHLEX experiment (REmote sensing of PHenology Larix Experiment), conducted by the Environmental Dynamics Remote Sensing Laboratory of the University of Milano-Bicocca, by the Regional Protection Agency of the Aosta Valley and by Vegetation Biology Department of the University of Torino. The project was aimed at developing appropriate techniques for monitoring the interannual variability of European Larch (Larix decidua Mill.) phenological cycle in the Alpine region of Valle d'Aosta (Northern Italy), and to evaluate its relationships with environmental and climatic drivers. This was achieved by combining field observations, phenological models and satellite remote sensing. Phenological field observations were weekly conducted in 8 test sites during 2005, 2006 and 2007 in order to determine the dates of completion of different phenological phases of the analyzed Larch stands. MODIS 250 16-days composite NDVI data (Product MOD13Q1 - v005) acquired from TERRA platform for the 2000-2007 time period were used to estimate budburst and senescence dates, as well as the length of the growing season. With this aim, NDVI time series were fitted with a double logistic curve, and the dates corresponding to different characteristic points of the curve (maximum of the first derivative and zeroes of the third and fourth derivative) were determined. The comparison between MODIS estimated dates and field data showed that the points of the fitted NDVI curve that allow to better estimate larch phenological dates are the zeroes of its third derivative, which allowed to estimate the start and the end of the growing season with Mean Absolute Errors (MAE) of about 6 and 4 days, respectively. This result is particularly significant since to our knowledge these inflection points have never been used for the estimation of phenological dates in previous studies. Start and end of season were also estimated by applying the Spring Warming and the

  4. Control of origin of larch wood: discrimination between European (Austrian) and Siberian origin by stable isotope analysis.

    PubMed

    Horacek, Micha; Jakusch, Michael; Krehan, Hannes

    2009-12-01

    Most of the coniferous wood of non-European origin that is imported into the European Union (EU) has to be inspected phytosanitarily, to prevent the introduction and spread of harmful pests in EU territory. Wood importers have been caught declaring Siberian larch wood as being of European origin to save the costs of the inspection. Therefore, an unequivocal method has to be developed in addition to the traditional analysis of the tree ring density to identify incorrect declarations of larch wood origin. For this purpose, delta18O and delta13C analyses have been carried out to check if Siberian larch wood can be discriminated from European larch. Measurements have been carried out on bulk wood samples, as the method has to be designed to be as simple as possible. The results show an overlapping of the Siberian and Austrian delta13C, and no overlapping for the delta18O values. Copyright 2009 John Wiley & Sons, Ltd.

  5. European larch phenology in the Alps: can we grasp the role of ecological factors by combining field observations and inverse modelling?

    PubMed

    Migliavacca, M; Cremonese, E; Colombo, R; Busetto, L; Galvagno, M; Ganis, L; Meroni, M; Pari, E; Rossini, M; Siniscalco, C; Morra di Cella, U

    2008-09-01

    Vegetation phenology is strongly influenced by climatic factors. Climate changes may cause phenological variations, especially in the Alps which are considered to be extremely vulnerable to global warming. The main goal of our study is to analyze European larch (Larix decidua Mill.) phenology in alpine environments and the role of the ecological factors involved, using an integrated approach based on accurate field observations and modelling techniques. We present 2 years of field-collected larch phenological data, obtained following a specifically designed observation protocol. We observed that both spring and autumn larch phenology is strongly influenced by altitude. We propose an approach for the optimization of a spring warming model (SW) and the growing season index model (GSI) consisting of a model inversion technique, based on simulated look-up tables (LUTs), that provides robust parameter estimates. The optimized models showed excellent agreement between modelled and observed data: the SW model predicts the beginning of the growing season (B(GS)) with a mean RMSE of 4 days, while GSI gives a prediction of the growing season length (L(GS)) with a RMSE of 5 days. Moreover, we showed that the original GSI parameters led to consistent errors, while the optimized ones significantly increased model accuracy. Finally, we used GSI to investigate interactions of ecological factors during springtime development and autumn senescence. We found that temperature is the most effective factor during spring recovery while photoperiod plays an important role during autumn senescence: photoperiod shows a contrasting effect with altitude decreasing its influence with increasing altitude.

  6. Bud gall midges - potential invaders on larches in North America

    Treesearch

    Yuri N. Baranchikov

    2007-01-01

    Larch bud gall midges (Diptera: Cecidomyiidae) form a specialized group of gall insects inhabiting buds of larch (Larix) in the northern Palaearctic Region. Currently there are four described species in this group. Dasineura kellneri Henschel is found in Central Europe and infests Larix decidua; D....

  7. Larix decidua δ(18)O tree-ring cellulose mainly reflects the isotopic signature of winter snow in a high-altitude glacial valley of the European Alps.

    PubMed

    Leonelli, Giovanni; Battipaglia, Giovanna; Cherubini, Paolo; Saurer, Matthias; Siegwolf, Rolf T W; Maugeri, Maurizio; Stenni, Barbara; Fusco, Stella; Maggi, Valter; Pelfini, Manuela

    2017-02-01

    We analyzed the chronologies of cellulose stable isotopes (δ(13)C and δ(18)O) and tree-ring widths from European larch (Larix decidua) in a high-altitude site (2190ma.s.l.) at the bottom of a glacial valley in the Italian Alps, and investigated their dependence on monthly meteorological variables and δ(18)O precipitation values. The δ(18)O of tree-ring cellulose appears to be strongly driven by the δ(18)O of winter snowfall (November to March), which suggests that larch trees mostly use the snow-melt water of the previous winter during the growing season. This water, which also comes from the slope streams and from the underground flow of nearby steep slopes, infiltrates the soil in the valley bottom. The tree-ring cellulose δ(18)O values were also found to be influenced by the August precipitation δ(18)O and mean temperature. The associated regression model shows that the δ(18)O chronology from the tree rings explains up to 34% of the variance in the winter precipitation δ(18)O record, demonstrating the potential for reconstructing the δ(18)O isotopic composition of past winter precipitation in the study region. Unlike most other tree-ring studies that focus on growing season signals, in our study the summer signal was small and the winter signal dominant due to the special conditions of the glacial valley. Site topography, geomorphology and soil characteristics in particular influence the stable isotope signal in tree-ring cellulose. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Disturbance and climate signal in Norway spruce and European larch dendrochronological series

    NASA Astrophysics Data System (ADS)

    Střelcová, Katarína; Fleischer, Peter, Jr.; Fleischer, Peter, Sr.; Holeksa, Jan; Zelo, Tomas; Vido, Jaroslav

    2017-04-01

    Norway spruce and European larch, dominant natural tree species in the Tatra Mountains (Slovakia), might be seriously threatened by projected climate change and intensified disturbance regime. Regional climate change scenarios project +2 °C increases in the 2050-2070 period and relatively stable precipitation regime when compared to long term normal. Such a climate change might shift both species on the edge of their bioclimatological conditions. Tree ring width is a good indicator of climate and disturbance impact on tree growth. The aim of our study was to identify abrupt growth changes indicating climatological stress on spruce and larch. We analysed local historical meteorological data (1890-2016) to reveal occurrence of such events in past. We hypothesize that number of stress days is increasing as a consequence of changing climate. Using band dendrometers we identified growth changes on five mature spruce and five larch trees during the 2008-2016 period. Each specific growth period was characterized by set of climatological parameters and indexes. Standardized precipitation index (SPI) and rate of photosynthesis (GPP) coincided well with abrupt growth decline, indicating physiological stress. These stress stimulating conditions were identified in past along historical climate records and verified on two-hundred tree cross sections. We applied combined step and trend intervention detection (CSTID) method for minimizing the effects of disturbance in tree ring width chronologies and enhance the climate signals.

  9. A 520 year record of summer sunshine for the eastern European Alps based on stable carbon isotopes in larch tree rings

    NASA Astrophysics Data System (ADS)

    Hafner, Polona; McCarroll, Danny; Robertson, Iain; Loader, Neil J.; Gagen, Mary; Young, Giles HF; Bale, Roderick J.; Sonninen, Eloni; Levanič, Tom

    2014-08-01

    A 520-year stable carbon isotope chronology from tree ring cellulose in high altitude larch trees ( Larix decidua Mill.), from the eastern European Alps, correlates more strongly with summer temperature than with summer sunshine hours. However, when instrumental records of temperature and sunshine diverge after AD1980, the tree ring time series does not follow warming summer temperatures but more closely tracks summer sunshine trends. When the tree ring stable carbon isotope record is used to reconstruct summer temperature the reconstruction is not robust. Reconstructed temperatures prior to the twentieth century are higher than regional instrumental records, and the evolution of temperature conflicts with other regional temperature reconstructions. It is concluded that sunshine is the dominant control on carbon isotope fractionation in these trees, via the influence of photosynthetic rate on the internal partial pressure of CO2, and that high summer (July-August) sunshine hours is a suitable target for climate reconstruction. We thus present the first reconstruction of summer sunshine for the eastern Alps and compare it with the regional temperature evolution.

  10. Introduced and Native Parasitoid Wasps Associated With Larch Casebearer (Lepidoptera: Coleophoridae) in Western Larch

    Treesearch

    M. Miller-Pierce; D. C. Shaw; A. Demarco; P. T. Oester

    2015-01-01

    The larch casebearer [Coleophora laricella (Hubner)], a non-native insect, continues to impact western larch (Larix occidentalis Nutt.) through defoliation events in the Pacific Northwest. Biological control programs starting in the 1960s released seven species of parasitoid wasps to control C. laricella...

  11. Influence of Long-Term Thinning on the Biomass Carbon and Soil Respiration in a Larch (Larix gmelinii) Forest in Northeastern China

    PubMed Central

    Wang, Huimei; Liu, Wei; Wang, Wenjie; Zu, Yuangang

    2013-01-01

    Thinning management is used to improve timber production, but only a few data are available on how it influences ecosystem C sink capacity. This study aims to clarify the effects of thinning on C sinks of larch plantations, the most widespread forests in Northeastern China. Both C influx from biomass production and C efflux from each soil respiration component and its temperature sensitivity were determined for scaling-up ecosystem C sink estimation: microbial composition is measured for clarifying mechanism for respiratory changes from thinning treatment. Thinning management induced 6.23 mol C m−2 yr−1 increase in biomass C, while the decrease in heterotrophic respiration (R h) at the thinned sites (0.9 mol C m−2 yr−1) has enhanced 14% of this biomass C increase. This decrease in R h was a sum of the 42% decrease (4.1 mol C m−2 yr−1) in litter respiration and 3.2 mol C m−2 yr−1 more CO2 efflux from mineral soil in thinned sites compared with unthinned control. Increases in temperature, temperature sensitivity, alteration of litters, and microbial composition may be responsible for the contrary changes in R h from mineral soil and litter respiration, respectively. These findings manifested that thinning management of larch plantations could enhance biomass accumulation and decrease respiratory efflux from soil, which resulted in the effectiveness improvement in sequestrating C in forest ecosystems. PMID:23710153

  12. Influence of long-term thinning on the biomass carbon and soil respiration in a larch (Larix gmelinii) forest in Northeastern China.

    PubMed

    Wang, Huimei; Liu, Wei; Wang, Wenjie; Zu, Yuangang

    2013-01-01

    Thinning management is used to improve timber production, but only a few data are available on how it influences ecosystem C sink capacity. This study aims to clarify the effects of thinning on C sinks of larch plantations, the most widespread forests in Northeastern China. Both C influx from biomass production and C efflux from each soil respiration component and its temperature sensitivity were determined for scaling-up ecosystem C sink estimation: microbial composition is measured for clarifying mechanism for respiratory changes from thinning treatment. Thinning management induced 6.23 mol C m⁻² yr⁻¹ increase in biomass C, while the decrease in heterotrophic respiration (R(h)) at the thinned sites (0.9 mol C m⁻²  yr⁻¹) has enhanced 14% of this biomass C increase. This decrease in R(h) was a sum of the 42% decrease (4.1 mol C m⁻²  yr⁻¹) in litter respiration and 3.2 mol C m⁻² yr⁻¹ more CO₂ efflux from mineral soil in thinned sites compared with unthinned control. Increases in temperature, temperature sensitivity, alteration of litters, and microbial composition may be responsible for the contrary changes in R h from mineral soil and litter respiration, respectively. These findings manifested that thinning management of larch plantations could enhance biomass accumulation and decrease respiratory efflux from soil, which resulted in the effectiveness improvement in sequestrating C in forest ecosystems.

  13. Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

    NASA Astrophysics Data System (ADS)

    Petrillo, M.; Cherubini, P.; Fravolini, G.; Ascher, J.; Schärer, M.; Synal, H.-A.; Bertoldi, D.; Camin, F.; Larcher, R.; Egli, M.

    2015-09-01

    Due to the large size and highly heterogeneous spatial distribution of deadwood, the time scales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests have been poorly investigated and are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the five-decay class system commonly employed for forest surveys, based on a macromorphological and visual assessment. For the decay classes 1 to 3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) and some others not having enough tree rings, radiocarbon dating was used. In addition, density, cellulose and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model. In the decay classes 1 to 3, the ages of the CWD were similar varying between 1 and 54 years for spruce and 3 and 40 years for larch with no significant differences between the classes; classes 1-3 are therefore not indicative for deadwood age. We found, however, distinct tree species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were 0.012 to 0.018 yr-1 for spruce and 0.005 to 0.012 yr-1 for larch. Cellulose and lignin time trends half-lives (using a multiple-exponential model) could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 yr for spruce and 50 yr for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD.

  14. Larch Casebearer in Western Larch

    Treesearch

    Scott Tunnock; Roger B. Ryan

    1995-01-01

    The larch casebearer (Coleophora laricella (Hubner), a native of Europe, was introduced into North America in 1886. The insect, which probably entered on planting stock, now infests almost all species of larch and tamarack in the United States.

  15. Drought response of five conifer species under contrasting water availability suggests high vulnerability of Norway spruce and European larch.

    PubMed

    Lévesque, Mathieu; Saurer, Matthias; Siegwolf, Rolf; Eilmann, Britta; Brang, Peter; Bugmann, Harald; Rigling, Andreas

    2013-10-01

    The ability of tree species to cope with anticipated decrease in water availability is still poorly understood. We evaluated the potential of Norway spruce, Scots pine, European larch, black pine, and Douglas-fir to withstand drought in a drier future climate by analyzing their past growth and physiological responses at a xeric and a mesic site in Central Europe using dendroecological methods. Earlywood, latewood, and total ring width, as well as the δ(13) C and δ(18) O in early- and latewood were measured and statistically related to a multiscalar soil water deficit index from 1961 to 2009. At the xeric site, δ(13) C values of all species were strongly linked to water deficits that lasted longer than 11 months, indicating a long-term cumulative effect on the carbon pool. Trees at the xeric site were particularly sensitive to soil water recharge in the preceding autumn and early spring. The native species European larch and Norway spruce, growing close to their dry distribution limit at the xeric site, were found to be the most vulnerable species to soil water deficits. At the mesic site, summer water availability was critical for all species, whereas water availability prior to the growing season was less important. Trees at the mesic were more vulnerable to water deficits of shorter duration than the xeric site. We conclude that if summers become drier, trees growing on mesic sites will undergo significant growth reductions, whereas at their dry distribution limit in the Alps, tree growth of the highly sensitive spruce and larch may collapse, likely inducing dieback and compromising the provision of ecosystem services. However, the magnitude of these changes will be mediated strongly by soil water recharge in winter and thus water availability at the beginning of the growing season. © 2013 John Wiley & Sons Ltd.

  16. Integrating proximal and satellite optical data for the analysis of ecosystem carbon uptake and plant phenology at the European larch Specnet site

    NASA Astrophysics Data System (ADS)

    Galvagno, Marta; Gamon, John; Cremonese, Edoardo; Garrity, Steven; Huemmrich, K. Fred; Filippa, Gianluca; Morra di Cella, Umberto; Rossini, Micol

    2017-04-01

    Automated canopy-level optical sampling in tandem with ecosystem-atmosphere flux observations is continuously carried on at a variety of ecosystems through the Specnet network (http://specnet.info/). Specifically, 9 sites within US and Europe were selected since 2015, to investigate the use of novel NDVI and PRI low-cost sensors for the analysis of ecosystem functioning and phenology. Different plant functional types, such as grasslands, deciduous, and evergreen forests belong to the network, here we present specific data from the larch (Larix decidua Mill.) forest Italian site. Three automated NDVI and three automated PRI spectral reflectance sensors (Decagon Devices Inc.) were installed in 2015 on the top of the 20-meters eddy covariance tower, pointing toward the west, north, and east orientations. An additional system, composed by one NDVI and PRI system was installed to monitor the understory component. The objective of this analysis is the comparison between these in-situ inexpensive sensors, independent NDVI and PRI sensors (Skye Instruments) previously installed on the 20-meters tower and satellite-derived NDVI. Both MODIS and Sentinel NDVI data were used for the comparison. Moreover, the newly derived chlorophyll/carotenoid index (CCI, Gamon et al. 2016), computed as the normalized difference between the NDVI red band and PRI 532 nm band, was tested to estimate the seasonal pattern of daily Gross Primary Productivity (GPP) of the larch forest. Results showed that the seasonality of NDVI was comparable among in-situ sensors and satellite data, though orientation-specific differences were observed. Both NDVI and CCI tracked daily GPP, but with different sensitivity to its seasonality. Future analysis will be directed toward a comparison between this site-based results with the other sites within the Specnet network.

  17. Container configuration influences western larch and big sagebrush seedling development

    Treesearch

    Matthew Mehdi. Aghai

    2012-01-01

    Big sagebrush (Artemisia tridentata Nutt.), a woody shrub, and western larch (Larix occidentalis Nutt.), a deciduous conifer, are among many western North American species that have suffered a decline in presence and natural regeneration across their native ranges. These species are economically, ecologically, and intrinsically valuable, therefore many current...

  18. Eight-year tree growth following prescribed underburning in a western Montana Douglas-fir/western larch stand

    Treesearch

    Elizabeth D. Reinhardt; Kevin C. Ryan

    1988-01-01

    Eight-year tree growth of western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii) was measured following prescribed underburning on burned and control plots in western Montana. Western larch on bun.ed plots had reduced radial growth in the first year following fire but increased growth in the next 7 years....

  19. Maturation in Larch 1

    PubMed Central

    Hutchison, Keith W.; Sherman, Christopher D.; Weber, Jill; Smith, Sandra Schiller; Singer, Patricia B.; Greenwood, Michael S.

    1990-01-01

    The effect of maturation on the morphological and photosynthetic characteristics, as well as the expression of two genes involved in photosynthesis in the developing, current year foliage of Eastern larch (Larix laricina [Du Roi]) is described. These effects were observed on foliage during the third growing season after grafting of scions from trees of different ages onto 2 year old rootstock. Specific leaf weight (gram dry weight per square meter), leaf cross-sectional area (per square millimeter), and chlorophyll content (milligram per gram dry weight) all increase with increasing age in long shoot foliage from both indoor- and outdoor-grown trees. Net photosynthesis (NPS) (mole of CO2 per square millimeter per second) increases with age on indoor- but not outdoor-grown trees. NPS also increases with increased chlorophyll content, but outdoor-grown scions of all ages had higher chlorophyll content, and chlorophyll does not appear to be limiting for NPS outdoors. To extend these studies of maturation-related differences in foliar morphology and physiology to the molecular genetic level, sequences were cloned from the cab and rbsS gene families of larch. Both cab and rbcS gene families are expressed in foliage but not in roots, and they are expressed in light-grown seedlings of larch but only at very low levels in dark-grown seedlings (~2% of light-grown seedlings). Steady-state cab mRNA levels are relatively higher (~40%) in newly expanding short shoot foliage from juvenile plants compared to mature plants. Unlike cab, the expression of the rbcS gene family did not seem to vary with age. These data show that the maturation-related changes in morphological and physiological phenotypes are associated with changes in gene expression. No causal relationship has been established, however. Indeed, we conclude that the faster growth of juvenile scions reported previously (MS Greenwood, CA Hopper, KW Hutchison [1989] Plant Physiol 90: 406-412) is not due to increased NPS

  20. Maturation in Larch 1

    PubMed Central

    Greenwood, Michael S.; Hopper, Catherine A.; Hutchison, Keith W.

    1989-01-01

    The time course of maturation in eastern larch (Larix laricina [Du Roi] K. Koch) was examined by grafting scions from trees of different ages onto 2-year-old root stock and following scion development for several years. Height, diameter, foliar chlorophyll content, and rooting ability of scion-derived cuttings all varied linearly as a function of log10 age. Chlorophyll content (milligrams per gram of dry weight) increased while height, diameter, and ability to root decreased with age (P < 0.01). The tendency toward orthotropic growth and branch formation per centimeter of main stem decreased abruptly between age 1 and 5 years (P < 0.01). Total chlorophyll content of both long and short shoot foliage increased by 30 to 50% with increasing age, but the chlorophyll a/b ratio did not change. Also, juvenile long shoot needles were significantly longer than mature (P < 0.01). Surprisingly, the juvenile scions produced more total strobili over two successive years, but the mature scions produced a significantly higher proportion of male strobili (P < 0.001 year 1; P < 0.02 year 2). The age-related changes in foliar traits were not associated with changes in DNA methylation between juvenile and mature scions. Using HPLC, we found that 20% of foliar DNA cytosine residues were methylated in both scion types. Images Figure 1 PMID:16666785

  1. Ophiostoma kryptum sp. nov. from Larix decidua and Picea abies in Europe, similar to O. minus.

    PubMed

    Jacobs, Karin; Kirisits, Thomas

    2003-10-01

    An unknown species of Ophiostoma was isolated from European larch (Larix decidua) infested by Tetropium gabrieli (Coleoptera: Cerambycidae) and Norway spruce (Picea abies) infested by Tetropium sp. in Austria. The fungus is similar to O. minus, but distinguished from it by the ecology, colony morphologies on OA and MEA, and phylogenetic analysis of aligned DNA sequences of the ITS region of the rDNA operon and the partial beta-tubulin gene. It is described here as O. kryptum sp. nov. The new species readily produces perithecia with short necks and reniform ascospores, and has Hyalorhinocladiella and Leptographium-like anamorphs. Circumstantial evidence suggests that Tetropium spp. act as vectors of O. kryptum. O. minus and O. kryptum represent additional examples of morphologically similar, yet genetically and ecologically distinct species in the genus Ophiostoma. The new combination, O. crenulatum comb. nov. (syn. CeratocYstiopsis crenulata), is also made.

  2. Larch dwarf mistletoe not found on alpine larch

    Treesearch

    Robert L. Mathiasen; Brian W. Geils; Clinton E. Carlson; Frank G. Hawksworth

    1995-01-01

    Reports of larch dwarf mistletoe parasitizing alpine larch are based on two collections of this host/parasite combination made by J.R. Weir in Montana during the early 1900s. Examination of host material from these collections indicates that the host is western larch, not alpine larch as previously reported. Attempts to locate larch dwarf mistletoe on alpine larch were...

  3. Does larch arabinogalactan enhance immune function? A review of mechanistic and clinical trials.

    PubMed

    Dion, Carine; Chappuis, Eric; Ripoll, Christophe

    2016-01-01

    The common cold is a viral infection with important economic burdens in Western countries. The research and development of nutritional solutions to reduce the incidence and severity of colds today is a major focus of interest, and larch arabinogalactan seems to be a promising supportive agent. Arabinogalactan has been consumed by humans for thousands of years and is found in a variety of common vegetables as well as in medicinal herbs. The major commercial sources of this long, densely branched, high-molecular-weight polysaccharide are North American larch trees. The aim of this article is to review the immunomodulatory effects of larch arabinogalactan derived from Larix laricina and Larix occidentalis (North American Larix species) and more specifically its role in the resistance to common cold infections. In cell and animal models, larch arabinogalactan is capable of enhancing natural killer cells and macrophages as well as the secretion of pro-inflammatory cytokines. In humans a clinical study demonstrated that larch arabinogalactan increased the body's potential to defend against common cold infection. Larch arabinogalactan decreased the incidence of cold episodes by 23 %. Improvements of serum antigen-specific IgG and IgE response to Streptococcus pneumoniae and tetanus vaccination suggesting a B cell dependent mechanism have been reported in vaccination studies with larch arabinogalactan, while the absence of response following influenza vaccination suggests the involvement of a T cell dependent mechanism. These observations suggest a role for larch arabinogalactan in the improvement of cold infections, although the mode of action remains to be further explored. Different hypotheses can be envisaged as larch arabinogalactan can possibly act indirectly through microbiota-dependent mechanisms and/or have a direct effect on the immune system via the gut-associated lymphoid tissue (GALT).

  4. Oxyfluorfen strongly affects Larix occidentalis but minimally affects Sagina procumbens in a bareroot nursery

    Treesearch

    R. Kasten Dumroese; Jasmine L. Williams; Jeremy R. Pinto; Peng Zhang

    2014-01-01

    Our objective was to evaluate oxyfluorfen for control of birdseye pearlwort (Sagina procumbens L.) in a bareroot nursery crop of western larch (Larix occidentalis Nutt.) seedlings. Oxyfluorfen applied at rates up to 0.56 kg a.i./ha in a split-plot experiment with combinations and frequencies of pre- and postemergence sprays gave minimal control of birdseye pearlwort....

  5. Water Relation Parameters of Embryogenic Cultures and Seedlings of Larch

    PubMed Central

    Livingston, Nigel J.; von Aderkas, Patrick; Fuchs, Edgar E.; Reaney, Martin J. T.

    1992-01-01

    Changes in the water relations parameters of developing somatic embryogenic and xygotic European larch (Larix decidua) were studied. Water release curves were generated by suspending tissue samples over unsaturated NaCl solutions until they reached vapor equilibration with the surrounding air. Twenty solutions were used whose water potentials ranged from −0.05 to −10 MPa. Water release curves were obtained by plotting paired values of tissue relative water content (RWC) and solution potential. Curves were derived for embryonic larch at various stages of development and for hypocotyls and roots from germinated zygotic and somatic embryos. The ability to resist dehydration increased markedly with development. Stage 1 tissue, which consisted of clusters of loosely associated nonchlorophyllous cells, had extremely low bulk elastic modulus (ε) (1.91 MPa) and apoplastic water content (A) (0.023), relatively high osmotic potential (Ψπ) (−0.53 MPa), and lost turgor at 0.56 RWC. In contrast, mature embryoids with primary roots, hypocotyl, and cotyledons (stage 3) had an almost 4-fold increase in A (0.089), significantly higher ε (3.49 MPa), and lower Ψπ (−0.88 MPa) and lost turgor at 0.66 RWC. Hypocotyl tissue from germinated somatic embryos lost turgor at 0.74 RWC and had higher ε, A, and solute accumulation than pregerminated tissue. Hypocotyl tissue resisted dehydration more strongly than root tissue, and differences between root and hypocotyl water relation parameters were more pronounced in xygotic than in somatic seedlings. Highest dehydration resistance was in zygotic hypocotyls. The characterization of the water relations of tissue cultures should allow the development of more consistent and reliable desiccation protocols to induce maturation of embryos and produce synchronously germinating seed. PMID:16653121

  6. Incidence of decay fungi in stumps of two thinned western larch stands in northeastern Oregon.

    Treesearch

    Gregory M. Filip; Catherine A. Parks; Kenneth W. Seidel; Frances F. Lombard

    1987-01-01

    Incidence of decay fungi was measured in stumps from two thinned western larch (Larix occidentalis Nutt.) stands (9 and 15 years after thinning), one precommercially thinned and one commercially thinned, in northeastern Oregon. Ten species of decay fungi were positively identified from 180 stumps. Two root pathogenic species, ...

  7. Biology and behavior of a larch bud moth, Zeiraphera sp., in Alaska.

    Treesearch

    Richard A. Werner

    1980-01-01

    A possibly new species or subspecies of larch bud moth of the genus Zeiraphera, closely related to Z. improbana (Walker), was found associated with tamarack, Larix laricina (Du Roi) K. Koch, stands in interior Alaska. An outbreak occurred during 1975 and 1976 over an area of 240 000 ha (590,000 acres)....

  8. A western larch-engelmann spruce spacing study in eastern Oregon: results after 10 years.

    Treesearch

    K.W. Seidel

    1984-01-01

    The 10-year growth response from a spacing study in an even-aged stand of western larch (Larix occidentalis Nutt.) and Engelmann spruce (Picea engelmannii Parry ex Engelm.), thinned at age 10 to 9- and 15-foot spacings, was measured in eastern Oregon. Both basal area and total cubic volume increment per acre increased at the...

  9. Performance of red pine and Japanese larch planted on anthracite coal-breaker refuse

    Treesearch

    Miroslaw M. Czapowskyj

    1973-01-01

    Red pine (Pinus resinosa Ait.) and Japanese larch (Larix leptolepis (Sieb. and Zucc.) Gord.) seedlings were planted on coal-breaker refuse with all combinations of two levels of lime, two levels of fertilizer, and four mulch treatments. The site was highly unfavorable as a medium for tree growth, and the 4-year results show...

  10. Nursery cultural practices to achieve targets: A case study in western larch irrigation

    Treesearch

    Anthony S. Davis; Robert F. Keefe

    2011-01-01

    Nursery cultural practices are used to help growers achieve pre-determined size and physiological targets for seedlings. In that regard, irrigation is used to accelerate or slow growth and as a trigger for changing growth phase. In a case study highlighting the effects of irrigation on seedling development, western larch (Larix occidentalis Nutt.) seedlings were grown...

  11. Connecting overwintering success of eastern larch beetle to health of tamarack. Chapter 16

    Treesearch

    Robert C. Venette; Abigail J. Walter

    2012-01-01

    Michigan, Wisconsin, Maine, and Minnesota have experienced extensive mortality of tamarack (eastern larch) (Larix laricina). The Minnesota Department of Natural Resources reported tamarack mortality on 54,000 acres of Minnesota forests between 2001 and 2006 (Minnesota Department of Natural Resources 2006). Although the exact cause of tree mortality...

  12. Ecological impacts and management strategies for western larch in the face of climate-change

    Treesearch

    Gerald E. Rehfeldt; Barry C. Jaquish

    2010-01-01

    Approximately 185,000 forest inventory and ecological plots from both USA and Canada were used to predict the contemporary distribution of western larch (Larix occidentalis Nutt.) from climate variables. The random forests algorithm, using an 8-variable model, produced an overall error rate of about 2.9 %, nearly all of which consisted of predicting presence at...

  13. Seasonal course of photosynthetic efficiency in Larix decidua Mill. in response to temperature and change in pigment composition during senescence.

    PubMed

    Galvagno, M; Rossini, M; Migliavacca, M; Cremonese, E; Colombo, R; Morra di Cella, U

    2013-11-01

    This manuscript presents a study aimed at characterizing the seasonal course of photosynthetic capacity of an alpine deciduous conifer, European larch (Larix decidua Mill.), based on chlorophyll fluorescence measurements and photosynthetic pigment analysis. The study focused on the characterization of autumn senescence events which (contrary to bud-burst) are still scarcely investigated. The study was conducted on two natural European larch stands in the northwestern Italian Alps during two consecutive years. The results show that photosynthetic efficiency as assessed by fluorescence measurements was controlled by variations in air and soil temperature. Photosynthesis responded to variations in maximum air and soil temperature in a delayed way, with a varying lag depending on the seasonal period considered. The analysis of photosynthetic efficiency and pigment decline at the end of the growing season identified two senescence phases. During early senescence, plants manifested only the beginning of needle decolouration, while during late senescence pigment degradation led to a loss in photosynthetic efficiency. This behavior indicates that the beginning of needle yellowing and the decline in photosynthetic efficiency can occur at different times-a finding that should be considered in order to improve models of ecosystem processes.

  14. Height growth to age 8 of larch species and hybrids in Wisconsin.

    Treesearch

    Don E. Riemenschneider; Hans Nienstaedt

    1983-01-01

    Height growth of tamarack; Siberian, European and Japanese larch; and hybrids between the European and Japanese larch were compared in an 8-year-old test in north-central Wisconsin. Hybrids were tallest and best reached 469 cm (15.4 feet) in mean height at age 8 years from seed. Hybrids exceeded European larch mean height by 12% and tamarack by 23%. Breeding...

  15. Resin duct size and density as ecophysiological traits in fire scars of Pseudotsuga menziesii and Larix occidentalis

    Treesearch

    Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

    2014-01-01

    Resin ducts (RDs) are features present in most conifer species as defence structures against pests and pathogens; however, little is known about RD expression in trees following fire injury. This study investigates changes in RD size and density in fire scars of Douglas fir (Pseudotsuga menziesii) and western larch (Larix occidentalis) as a means to evaluate the...

  16. Effect of fall-applied nitrogen on growth, nitrogen storage, and frost hardiness of bareroot Larix olgensis seedlings

    Treesearch

    Guolei Li; Yong Liu; Yan Zhu; Qingmei Li; R. Kasten Dumroese

    2012-01-01

    Nursery response of evergreen trees to fall fertilization has been studied widely, but little attention has been given to deciduous trees. Bareroot Olga Bay larch (Larix olgensis Henry) seedlings were fertilized in the nursery with urea at four rates (0, 30, 60, 90 kg N ha-1), with half of each rate applied on two dates (September 16 and October 1, 2009). The seedlings...

  17. New labdane diterpenes from the stem bark of Larix laricina.

    PubMed

    Pichette, André; Lavoie, Serge; Morin, Pierre; Mshvildadze, Vakhtang; Lebrun, Maxime; Legault, Jean

    2006-10-01

    Two new labdane diterpenes, cis-19-hydroxyabienol (1) and 8alpha-hydroxy-12Z,14-labdadien-19-al (2), along with another labdane described for the first time in the genus Larix, 19-acetoxy-13S-hydroxy-8(17),14-labdadiene (3) and a stilbene, 3-methoxy-3,3',5'-trihydroxystilbene (4), were isolated from the stem bark of Larch (Larix laricina). Their structures were established by standard chemical and spectroscopic methods. Compounds 2 and 3 were shown to be moderately cytotoxic against A-549, DLD-1 and normal skin fibroblast cell lines, WS1. Compound 1 was found to be selectively active against colon carcinoma cell lines, DLD-1.

  18. Growth and yield of western larch in response to several density levels and two thinning methods: 15-year results.

    Treesearch

    K.W. Seidel

    1986-01-01

    The 15-year growth response from a levels-of-growing-stock study in an even-aged western larch (Larix occidentalis Nutt.) stand, first thinned from above and below at age 55, was measured in northeastern Oregon. Basal area and volume growth increased with stand density for both thinning methods, whereas diameter growth decreased. Attacks of the...

  19. Rockfall and snow avalanche impacts leave different anatomical signatures in tree rings of juvenile Larix decidua.

    PubMed

    Stoffel, Markus; Hitz, Oliver M

    2008-11-01

    Rockfall and snow avalanche events often cause injury to European larch (Larix decidua Mill.) trees, giving rise to the formation of callus tissue and tangential rows of traumatic resin ducts (TRDs). We analyzed and quantified anatomical reactions of juvenile trees injured before the start of the growing season by snow avalanches (15 trees, 324 cross sections) or rockfalls (18 trees, 270 cross sections). Traumatic resin ducts were observed in the growth ring formed following injury in 94.3% of the rockfall samples and 87.3% of the snow avalanche samples. Traumatic resin ducts were formed at the beginning of the new annual ring around wounds caused by rockfalls. In contrast, in trees injured by snow avalanches, TRDs were not formed until after the formation of several rows of early earlywood (EE) tracheids (mean +/- SD = 4.19 +/- 2.56 rows). The dimensions of the EE tracheids observed in the snow avalanche samples were greatly reduced in the tissues bordering the wound, with radial width reaching an average of only 50% and lumen cross-sectional area an average of only 46% of pre-event values. It is therefore possible to differentiate injuries due to past snow avalanches from injuries due to rockfall based on anatomical growth reactions in the tissues bordering scars.

  20. Influence of topographic heterogeneity on the abandance of larch forest in eastern Siberia

    NASA Astrophysics Data System (ADS)

    Sato, H.; Kobayashi, H.

    2016-12-01

    In eastern Siberia, larches (Larix spp.) often exist in pure stands, constructing the world's largest coniferous forest, of which changes can significantly affect the earth's albedo and the global carbon balance. We have conducted simulation studies for this vegetation, aiming to forecast its structures and functions under changing climate (1, 2). In previous studies of simulating vegetation at large geographical scales, the examining area is divided into coarse grid cells such as 0.5 * 0.5 degree resolution, and topographical heterogeneities within each grid cell are just ignored. However, in Siberian larch area, which is located on the environmental edge of existence of forest ecosystem, abundance of larch trees largely depends on topographic condition at the scale of tens to hundreds meters. We, therefore, analyzed patterns of within-grid-scale heterogeneity of larch LAI as a function of topographic condition, and examined its underlying reason. For this analysis, larch LAI was estimated for each 1/112 degree from the SPOT-VEGETATION data, and topographic properties such as angularity and aspect direction were estimated form the ASTER-GDEM data. Through this analysis, we found that, for example, sign of correlation between angularity and larch LAI depends on hydrological condition on the grid cell. We then refined the hydrological sub-model of our vegetation model SEIB-DGVM, and validated whether the modified model can reconstruct these patterns, and examined its impact on the estimation of biomass and vegetation productivity of entire larch region. -- References --1. Sato, H., et al. (2010). "Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM." Forest Ecology and Management 259(3): 301-311.2. Sato, H., et al. (2016). "Endurance of larch forest ecosystems in eastern Siberia under warming trends." Ecology and Evolution

  1. Endurance of larch forest ecosystems in eastern Siberia under warming trends

    NASA Astrophysics Data System (ADS)

    Sato, H.; Iwahana, G.; Ohta, T.

    2015-12-01

    The larch (Larix spp.) forest in eastern Siberia is the world's largest coniferous forest. However, its existence depends on near-surface permafrost, which increases water availability for trees, and the boundary of the forest closely follows the permafrost zone. Therefore, the degradation of near-surface permafrost due to forecasted warming trends during the 21st century is expected to affect the larch forest in Siberia. However, predictions of how warming trends will affect this forest vary greatly, and many uncertainties remain about land-atmospheric interactions within the ecosystem. We developed an integrated land surface model to analyze how the Siberian larch forest will react to current warming trends. This model analyzed interactions between vegetation dynamics and thermo-hydrology and showed that, under climatic conditions predicted by the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathway (RCP) scenarios 2.6 and 8.5, annual larch net primary production (NPP) increased about 2 and 3 times, respectively, by the end of 21st century compared with that in the 20th century. Soil water content during larch growing season showed no obvious trend, even after decay of surface permafrost and accompanying sub-surface runoff. A sensitivity test showed that the forecasted warming and pluvial trends extended leafing days of larches and reduced water shortages during the growing season, thereby increasing productivity.

  2. Comprehensive Spectral Signal Investigation of a Larch Forest Combining - and Satellite-Based Measurements

    NASA Astrophysics Data System (ADS)

    Landmann, J. M.; Rutzinger, M.; Bremer, M.; chmidtner, K.

    2016-06-01

    Collecting comprehensive knowledge about spectral signals in areas composed by complex structured objects is a challenging task in remote sensing. In the case of vegetation, shadow effects on reflectance are especially difficult to determine. This work analyzes a larch forest stand (Larix decidua MILL.) in Pinnis Valley (Tyrol, Austria). The main goal is extracting the larch spectral signal on Landsat 8 (LS8) Operational Land Imager (OLI) images using ground measurements with the Cropscan Multispectral Radiometer with five bands (MSR5) simultaneously to satellite overpasses in summer 2015. First, the relationship between field spectrometer and OLI data on a cultivated grassland area next to the forest stand is investigated. Median ground measurements for each of the grassland parcels serve for calculation of the mean difference between the two sensors. Differences are used as "bias correction" for field spectrometer values. In the main step, spectral unmixing of the OLI images is applied to the larch forest, specifying the larch tree spectral signal based on corrected field spectrometer measurements of the larch understory. In order to determine larch tree and shadow fractions on OLI pixels, a representative 3D tree shape is used to construct a digital forest. Benefits of this approach are the computational savings compared to a radiative transfer modeling. Remaining shortcomings are the limited capability to consider exact tree shapes and nonlinear processes. Different methods to implement shadows are tested and spectral vegetation indices like the Normalized Difference Vegetation Index (NDVI) and Greenness Index (GI) can be computed even without considering shadows.

  3. Climate-Induced Larch Growth Response Within the Central Siberian Permafrost Zone

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Ranson, Kenneth J.; Im, Sergei T.; Petrov, Il'ya A.

    2015-01-01

    Aim: estimation of larch (Larix gmelinii) growth response to current climate changes. Location: permafrost area within the northern part of Central Siberia (approximately 65.8 deg N, 98.5 deg E). Method: analysis of dendrochronological data, climate variables, drought index SPEI, GPP (gross primary production) and EVI vegetation index (both Aqua/MODIS satellite derived), and soil water content anomalies (GRACE satellite measurements of equivalent water thickness anomalies, EWTA). Results: larch tree ring width (TRW) correlated with previous year August precipitation (r = 0.63), snow accumulation (r = 0.61), soil water anomalies (r = 0.79), early summer temperatures and water vapor pressure (r = 0.73 and r = 0.69, respectively), May and June drought index (r = 0.68-0.82). There are significant positive trends of TRW since late 1980s and GPP since the year 2000. Mean TRW increased by about 50%, which is similar to post-Little Ice Age warming. TRW correlated with GPP and EVI of larch stands (r = 0.68-0.69). Main conclusions: within the permafrost zone of central Siberia larch TRW growth is limited by early summer temperatures, available water from snowmelt, water accumulated within soil in the previous year, and permafrost thaw water. Water stress is one of the limiting factors of larch growth. Larch TRW growth and GPP increased during recent decades.

  4. Climate-Induced Larch Growth Response Within the Central Siberian Permafrost Zone

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Ranson, Kenneth J.; Im, Sergei T.; Petrov, Il'ya A.

    2015-01-01

    Aim: estimation of larch (Larix gmelinii) growth response to current climate changes. Location: permafrost area within the northern part of Central Siberia (approximately 65.8 deg N, 98.5 deg E). Method: analysis of dendrochronological data, climate variables, drought index SPEI, GPP (gross primary production) and EVI vegetation index (both Aqua/MODIS satellite derived), and soil water content anomalies (GRACE satellite measurements of equivalent water thickness anomalies, EWTA). Results: larch tree ring width (TRW) correlated with previous year August precipitation (r = 0.63), snow accumulation (r = 0.61), soil water anomalies (r = 0.79), early summer temperatures and water vapor pressure (r = 0.73 and r = 0.69, respectively), May and June drought index (r = 0.68-0.82). There are significant positive trends of TRW since late 1980s and GPP since the year 2000. Mean TRW increased by about 50%, which is similar to post-Little Ice Age warming. TRW correlated with GPP and EVI of larch stands (r = 0.68-0.69). Main conclusions: within the permafrost zone of central Siberia larch TRW growth is limited by early summer temperatures, available water from snowmelt, water accumulated within soil in the previous year, and permafrost thaw water. Water stress is one of the limiting factors of larch growth. Larch TRW growth and GPP increased during recent decades.

  5. Endurance of larch forest ecosystems in eastern Siberia under warming trends.

    PubMed

    Sato, Hisashi; Kobayashi, Hideki; Iwahana, Go; Ohta, Takeshi

    2016-08-01

    The larch (Larix spp.) forest in eastern Siberia is the world's largest coniferous forest. Its persistence is considered to depend on near-surface permafrost, and thus, forecast warming over the 21st century and consequent degradation of near-surface permafrost is expected to affect the larch forest in Siberia. However, predictions of these effects vary greatly, and many uncertainties remain about land - atmosphere interactions within the ecosystem. We developed an integrated land surface model to analyze how the Siberian larch forest will react to current warming trends. This model analyzed interactions between vegetation dynamics and thermo-hydrology, although it does not consider many processes those are considered to affect productivity response to a changing climate (e.g., nitrogen limitation, waterlogged soil, heat stress, and change in species composition). The model showed that, under climatic conditions predicted under gradual and rapid warming, the annual net primary production of larch increased about 2 and 3 times, respectively, by the end of the 21st century compared with that in the previous century. Soil water content during the larch-growing season showed no obvious trend, even when surface permafrost was allowed to decay and result in subsurface runoff. A sensitivity test showed that the forecast temperature and precipitation trends extended larch leafing days and reduced water shortages during the growing season, thereby increasing productivity. The integrated model also satisfactorily reconstructed latitudinal gradients in permafrost presence, soil moisture, tree leaf area index, and biomass over the entire larch-dominated area in eastern Siberia. Projected changes to ecosystem hydrology and larch productivity at this geographical scale were consistent with those from site-level simulation. This study reduces the uncertainty surrounding the impact of current climate trends on this globally important carbon reservoir, and it demonstrates the need

  6. Inhibition of melanin production by a combination of Siberian larch and pomegranate fruit extracts.

    PubMed

    Diwakar, Ganesh; Rana, Jatinder; Scholten, Jeffrey D

    2012-09-01

    In an effort to find botanicals containing polyphenolic compounds with the capacity to inhibit melanin biosynthesis, we identified a novel combination of Siberian larch (Larix sibirica) extract, standardized to 80% taxifolin, and pomegranate fruit (Punica granatum) extract, containing 20% punicalagins, that demonstrates a synergistic reduction of melanin biosynthesis in Melan-a cells. The combination of Siberian larch and pomegranate extracts (1:1) produced a 2-fold reduction in melanin content compared to Siberian larch or pomegranate extracts alone with no corresponding effect on cell viability. Siberian larch and pomegranate fruit extracts inhibited expression of melanocyte specific genes, tyrosinase (Tyr), microphthalmia transcription factor (Mitf), and melanosome structural proteins (Pmel17 and Mart1) but did not inhibit tyrosinase enzyme activity. These results suggest that the mechanism of inhibition of melanin biosynthesis by Siberian larch and pomegranate extracts, alone and in combination, is through downregulation of melanocyte specific genes and not due to inhibition of tyrosinase enzyme activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Long-term change in the sensitivity of tree-ring growth to climate forcing in Larix decidua.

    PubMed

    Carrer, Marco; Urbinati, Carlo

    2006-01-01

    Tree rings are widely used long-term proxy data which, if combined with long-term instrumental climate records, can provide excellent information on global climate variability. This research aimed to determine whether interannual climate-growth responses in Alpine treeline forests are stationary over time. We used tree-ring width chronologies of Larix decidua (European larch) from 17 sites and monthly temperatures and precipitation data for the period 1800-1999. Climate-growth relationships were assessed with correlation and response functions, and their stationarity and consistency over time were measured using moving correlation. Tree-ring chronologies showed similar interannual variations over the last two centuries, suggesting that the same climatic factors synchronously limited growth at most sites. The most sensitive variables showed significant transient responses varying within the time period, indicating a possible deviation from the uniformitarian principle applied to dendroclimatology. If these findings are confirmed in future studies on other species and in other regions, we suggest that time-dependent variables should be taken into account to avoid overestimation of treeline advance, future forest carbon storage in temperature-limited environments and inaccurate reconstruction of past climate variability.

  8. Larch Litter Removal Has No Significant Effect On Runoff

    Treesearch

    Richard S. Startz; David N. Tolsted

    1974-01-01

    Runoff was measured on paired litter-removed, litter-left plots in an 11-year-old European larch plantation. On five of the six pairs of plots, the plot with the litter left intact yielded more runoff. however, the differences were neither statistically nor hydrologically significant.

  9. Introduced and Native Parasitoid Wasps Associated With Larch Casebearer (Lepidoptera: Coleophoridae) in Western Larch.

    PubMed

    Miller-Pierce, M; Shaw, D C; Demarco, A; Oester, P T

    2015-02-01

    The larch casebearer [Coleophora laricella (Hubner)], a non-native insect, continues to impact western larch (Larix occidentalis Nutt.) through defoliation events in the Pacific Northwest. Biological control programs starting in the 1960s released seven species of parasitoid wasps to control C. laricella outbreaks. However, information about current population dynamics of C. laricella and associated parasitoids remains lacking. Therefore, the goal of this study was to document the presence, current distributions, densities, and parasitism rates of introduced and native parasitoid wasps occurring on C. laricella throughout the Northwestern U.S. range of L. occidentalis. We sampled L. occidentalis trees at multiple sites in Oregon, Washington, Idaho, and Montana. C. laricella was present at all sites with average state densities ranging from 6.2 to 13.1 moths/100 buds. We recovered two introduced hymenopteran biological control agents; Agathis pumila (Ratzeburg: Braconidae) at 79% of the sites, and Chrysocharis laricinellae (Ratzeburg: Eulophidae) at 63% of the sites. Fourteen species of native parasitic wasps were also recovered. The most common species were: Bracon sp., Spilochalcis albifrons, and Mesopolobus sp. The average native species parasitism rate across the four states was 9.0%, which was higher than the introduced species Ch. laricinellae (2.9%), but not as high as A. pumila (19.3%). While survey results suggest that native species may be more important for the control of C. laricella than previously thought, A. pumila remains the major source of regional control. However, further research is needed to better understand how introduced and native parasitoids interact to control invasive pest populations. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Tree-ring growth patterns and climatic signals along a vertical transect of larch sites in the Simplon and Rhône Valleys (Switzerland)

    NASA Astrophysics Data System (ADS)

    Riechelmann, Dana F. C.; Esper, Jan

    2017-04-01

    State-of-the-art millennial long temperature reconstructions from the European Alps integrate wood samples of Larix decidua Mill. from the Lötschental and Simplon regions in Switzerland (Büntgen et al., 2005; 2006). Some of the oldest samples that enable the extension of the time-series back into the first millennium AD are obtained from old buildings in Simplon Village, through the precise location of these samples and the elevation of sampling sites remain unknown. We here evaluate the growth characteristics of larch tree-ring width data along a vertical transect in the Simplon and Rhône valleys. 330 trees from nine sites in 985, 1100, 1400, 1575, 1710, 1712, 1900, 2020, and 2150 m asl have been sampled and analysed for their climate signals. The results indicate a stronger temperature signal in the tree-ring width with increasing elevation. The lower the sites the more a drought signal is imprinted in the ring width data. The intermediate site at 1400 m asl does not show any pronounced climate signal. A comparison of growth patterns of living-tree sites with samples from the historical buildings in Simplon Village (Riechelmann et al., 2013) indicates the construction timber to origin from intermediate to higher elevations. We therefore do not expect strong temperature signal from these timbers. References: Büntgen, U., Esper, J., Frank, D.C., Nicolussi, K., Schmidhalter, M., 2005. A 1052-year tree-ring proxy for Alpine summer temperatures. Climate Dynamics 25: 141-153. Büntgen, U., Frank, D.C., Nievergelt, D., Esper J., 2006. Summer temperature variations in the European Alps, A.D. 755-2004. Journal of Climate 19: 5606-5623. Riechelmann, D.F.C., Schmidhalter, M., Büntgen, U., Esper, J., 2013. Extending a high-elevation larch ring width chronology from the Simplon region in the Swiss Alps over the past millenium. TRACE 11:103-108.

  11. Fire Return Interval Within the Northern Boundary of the Larch Forest

    NASA Technical Reports Server (NTRS)

    Kharuk, V. I.; Dvinskaya, M. L.; Ranson, K. J.

    2011-01-01

    Larch (Larix spp.) dominant forests compose a large proportion of the forests of Russia (i.e., about 40% of forested areas). These forests range from the Yenisei ridge on the west to the Pacific Ocean on the east, and from Lake Baikal on the south to the 73rd parallel in the north. Larch stands comprise the world s northern most forest at Ary-Mas (72 deg 28' N, 102 deg 15' E). Larch dominated forests occupy about 70% of the permafrost areas in Siberia. Larch forms high closure stands as well as open forests, and is found mainly over permafrost, where other tree species barely survive. Wildfires are typical for this territory with the majority occurring as ground fires due to low crown closure. Due to the thin active layer in permafrost soils and a dense lichen-moss cover, ground fires may cause stand mortality. The vast areas of larch-dominant forests is generally considered as a "carbon sink"; however, positive long-term temperature trends at higher latitudes are expected to result in an increase of fire frequency, and thus may convert this area to a source for greenhouse gases. There are recent observations regarding the increase of fire frequency within non-protected territories. Surprisingly, there are few publications on fire chronoseqences for the huge forested territory between the Ural Mountains and the Pacific Ocean. Also there is a general understanding that bimodal (late spring -- early summer and late summer-beginning of fall) fire seasonal distribution in the south becomes uni-modal (late spring -- early summer) in the north. The purpose of this study is to investigate the wildfire history at the northern edge of the zone of larch dominance.

  12. Chemical basis of differential feeding behavior of the larch sawfly,Pristiphora erichsonii (Hartig).

    PubMed

    Ohigashi, H; Wagner, M R; Mastumura, F; Benjamin, D M

    1981-05-01

    The machanisms by which the larvae of the larch sawfly,Pristiphora erichsonii (Hartig), are prevented from feeding on the single needles of the new shoot of tamarack,Larix laricina (DuRoi) K. Koch, were studied. As a result of extensive purification attempts, five deterrent chemicals were isolated and identified. They are: abietic, dehydroabietic, 12-methoxyabietic, sandaracopimaric, and isopimaric acid. These chemicals, particularly the first two, are abundant in mid-July to August in the single needles and, apparently, provide the basis for the deterrency against the larval feeding.

  13. Water relations and photosynthetic performance in Larix sibirica growing in the forest-steppe ecotone of northern Mongolia.

    PubMed

    Dulamsuren, Choimaa; Hauck, Markus; Bader, Martin; Osokhjargal, Dalaikhuu; Oyungerel, Shagjjav; Nyambayar, Suran; Runge, Michael; Leuschner, Christoph

    2009-01-01

    Shoot water relations were studied in Siberian larch (Larix sibirica Ledeb.) trees growing at the borderline between taiga and steppe in northern Mongolia. Larix sibirica is the main tree species in these forests covering 80% of Mongolia's forested area. Minimum shoot water potentials (Psi(m)) close to the point of zero turgor (Psi(0)) repeatedly recorded throughout the growing season suggest that the water relations in L. sibirica were often critical. The Psi(m) varied in close relation to the atmospheric vapor pressure deficit, whereas Psi(0) was correlated with monthly precipitation. Young larch trees growing at the forest line to the steppe were more susceptible to drought than mature trees at the same sites. Furthermore, isolated trees growing on the steppe exhibited lower Psi(m) and recovered to a lower degree from drought overnight than the trees at the forest line. Indications of drought stress in L. sibirica were obtained in two study areas in Mongolia's forest-steppe ecotone: one in the mountain taiga of the western Khentey in northernmost Mongolia, the other in the forest-steppe at the southern distribution limit of L. sibirica on Mt. Bogd Uul, southern Khentey. Larix sibirica growing in riverine taiga with contact to the groundwater table was better water-supplied than the larch trees growing at the forest line to the steppe. Larch trees from the interior of light taiga forests on north-facing slopes, however, exhibited more critical water relations than the trees at the forest line. Frequent drought stress in mature trees and even more in young larch trees at the forest-steppe borderline suggests that L. sibirica does not have the potential to encroach on the steppe under the present climate, except in a sequence of exceptionally moist and cool years. A regression of the present borderline between forest and steppe is likely to occur, as average temperatures are increasing everywhere and precipitation is decreasing regionally in Mongolia's taiga forest

  14. [Nucleotide diversity and linkage disequilibrium of adaptive significant genes in Larix (Pinaceae)].

    PubMed

    Semerikov, V L; Semerikova, S A; Polezhaeva, M A

    2013-09-01

    Nucleotide polymorphism in genes potentially responsible for the adaptation to the latitudinal gradient of climate was investigated in the Siberian larch (Larix sibirica). The genes were selected among those previously studied in Douglas fir (Pseudotsuga menziesii), the variability of which indicates the influence of selection or shows the association with phenotypic traits that are important for adaptation to low temperatures and to geographically heterogeneous environment. Nucleotide sequences of eight genes, including coding and noncoding regions, were amplified and sequenced using newly developed primers specific to Larix. The sample size was 123 megagametophytes per locus in L. sibirica and 16.2 in L. occidentalis, which was taken as the out-group. The length of the sequenced fragments was 246-1700 bp. Nucleotide polymorphism π averaged 0.00536 (0.002 - 0.008), and haplotype diversity was H(d): 0.822 (0.625-0.948). Tajima's D was negative in all fragments and significant in three, while statistics D* and F* was significant in three and four segments, respectively, and F(s) was significant in three. This may indicate the presence of purifying selection on these genes or population growth. The HKA test revealed no significant deviations from the neutral model of evolution in all genes. The recombination parameter ρ/θ = 0.28 was close to the value obtained from P. menziesii. To investigate the association of polymorphic sites (factor) in these eight genes to the latitude of investigated individuals (trait), the generalized linear model (GLM) was used taking into account the population structure. After the False Discovery Rate correction no significant associations were found. The age of the split of American and Eurasian Larix lineages based on the nucleotide differences in the eight genes between L. sibirica and L. occidentalis is estimated to be 12 million years, which is much younger than the age of the most ancient Larix discoveries.

  15. Climate-Driven Changes Within the Larch Forest of Northern Siberia

    NASA Astrophysics Data System (ADS)

    Kharuk, V.

    2015-12-01

    Thanks to the support of NASA's Carbon Cycle and Ecosystem Focus Area programs, joint NASA/ Siberian Branch of the Russian Academy of Sciences studies have been conducted throughout Siberia. The overall objective has been to obtain field and satellite measurements to examine carbon stocks and track changes in forests across this vast area. In this presentation, we discuss some of the finding from this 25+ year collaboration' i.e., observed climate-driven changes within larch communities in northern Siberia. Field measurements and satellite data, including Terra/MODIS, Landsat, GRACE and QuickBird were used for analysis of forest conditions. The following results will be discussed. (1). At the northern limit of larch (Larix gmelinii) range (i.e.,~72°N) tree mortality was observed during the cooling period from the 16th century to the beginning of the 19th century. Post- Little Ice Age (LIA) trees re-establishment followed warming temperatures by the middle of the19th century. The current tree line has recovered to the pre-LIA line location although tree heights and stand densities are comparatively lower. The mean rate of upward migration was found to be 0.35 m yr-1 (with a range of 0.21-0.58). (2) The migration of the "dark needle conifers" (DNC: Abies sibirica, Pinus sibirica, Picea obovata) into the southern margin zone of larch dominated forest was documented. Meanwhile, within the traditional DNC range decline and mortality of both Siberian pine and fir were observed and attributed, primarily, due to an increased drought. (3) Within Central Siberia larch growth is limited by early summer temperatures and available water from thawing permafrost. Larch tree ring width (TRW) correlated with early summer temperatures and water vapor pressure (r = 0.73 and r = 0.69, respectively), drought (SPEI; r = 0.68-0.82), snow accumulation (r = 0.61), previous year precipitation (r = 0.63) and soil water anomalies (r = 0.79). Larch TRW growth and Gross Primary Productivity

  16. A Physicochemical and Pharmacological Study of the Newly Synthesized Complex of Albendazole and the Polysaccharide Arabinogalactan from Larch Wood.

    PubMed

    Chistyachenko, Yulia S; Meteleva, Elizaveta S; Pakharukova, Maria Y; Katokhin, Aleksey V; Khvostov, Mikhail V; Varlamova, Anastasiya I; Glamazdin, Igor I; Khalikov, Salavat S; Polyakov, Nikolay E; Arkhipov, Ivan A; Tolstikova, Tatyana G; Mordvinov, Viatcheslav A; Dushkin, Alexander V; Lyakhov, Nikolay Z

    2015-01-01

    Inclusion complexes of albendazole (ABZ) with the polysaccharide arabinogalactan from larch wood Larix sibirica and Larix gmelinii were synthesized using a solid-state mechanochemical technology. We investigated physicochemical properties of the synthesized complexes in the solid state and in aqueous solutions as well as their anthelmintic activity against Trichinella spiralis, Hymenolepis nаna, Fasciola hepatica, Opisthorchis felineus, and mixed nematodoses of sheep. Formation of the complexes was demonstrated by means of intrinsic solubility and the NMR relaxation method. The mechanochemically synthesized complexes were more stable in comparison with the complex produced by mixing solutions of the components. The complexes of ABZ showed anthelmintic activity at 10-fold lower doses than did free ABZ. The complexes also showed lower acute toxicity and hepatotoxicity. These results suggest that it is possible to design new drugs on the basis of the ABZ:arabinogalactan complex that are safer and more effective than albendazole.

  17. [Induction of androgenic cultures in Siberian larch].

    PubMed

    Ivanova, A N; Tret'iakova, I N; Viazovetskova, A S

    2006-01-01

    Male generative buds of the Siberian larch have no organic quiescence during the autumn-winter period and are capable of completing the development of male generative structures under favorable conditions. When microsporophylls of the Siberian larch were cultivated on medium MS with 0.2 mg/l 2,4-D, embryoids of two types were obtained: directly from the microspore body and via formation of organogenic callus. This means that in the Siberian larch, direct and indirect androgenesis in vitro is possible. The Siberian larch pollen was first germinated in vitro, which was enhanced by pretreatment with hydrogen peroxide.

  18. Characterization of condensed tannins and carbohydrates in hot water bark extracts of European softwood species.

    PubMed

    Bianchi, Sauro; Kroslakova, Ivana; Janzon, Ron; Mayer, Ingo; Saake, Bodo; Pichelin, Frédéric

    2015-12-01

    Condensed tannins extracted from European softwood bark are recognized as alternatives to synthetic phenolics. The extraction is generally performed in hot water, leading to simultaneous extraction of other bark constituents such as carbohydrates, phenolic monomers and salts. Characterization of the extract's composition and identification of the extracted tannins' molecular structure are needed to better identify potential applications. Bark from Silver fir (Abies alba [Mill.]), European larch (Larix decidua [Mill.]), Norway spruce (Picea abies [Karst.]), Douglas fir (Pseudotsuga menziesii [Mirb.]) and Scots pine (Pinus sylvestris [L.]) were extracted in water at 60°C. The amounts of phenolic monomers, condensed tannins, carbohydrates, and inorganic compounds in the extract were determined. The molecular structures of condensed tannins and carbohydrates were also investigated (HPLC-UV combined with thiolysis, MALDI-TOF mass spectrometry, anion exchange chromatography). Distinct extract compositions and tannin structures were found in each of the analysed species. Procyanidins were the most ubiquitous tannins. The presence of phenolic glucosides in the tannin oligomers was suggested. Polysaccharides such as arabinans, arabinogalactans and glucans represented an important fraction of all extracts. Compared to traditionally used species (Mimosa and Quebracho) higher viscosities as well as faster chemical reactivities are expected in the analysed species. The most promising species for a bark tannin extraction was found to be larch, while the least encouraging results were detected in pine. A better knowledge of the interaction between the various extracted compounds is deemed an important matter for investigation in the context of industrial applications of such extracts.

  19. Genetic relationship among eurasian and american larix species based on allozymes

    PubMed

    Semerikov; Lascoux

    1999-07-01

    Genetic variation at 16 allozyme loci was studied in both American (Larix occidentalis Nutt., L. laricina (Du Roi) C. Koch, L. lyallii Parl.) and Eurasian (L. sibirica Ledeb., L. gmelinii Rupr., L. olgensis A. Henry, L. kaempferi (Lamb.) Carr. (=L. leptolepis (Sieb. et Zucc.) Endl.), L. kamtschatica (Rupr.) Carr. and L. decidua (Mill. )) larch species. Species with a limited range, such as L. olgensis and L. lyallii, had lower genetic variation than species with a wider range. Population differentiation within species was of the same order of magnitude among species. The resulting phylogeny indicates a clear separation between American and Eurasian species. This result is in agreement with recent palaeontological findings that suggest that gene flow between American and Eurasian species has been unlikely since the last glaciation.

  20. Wildfires dynamic in the larch dominance zone

    NASA Astrophysics Data System (ADS)

    Kharuk, Viacheslav I.; Ranson, K. Jon; Dvinskaya, Maria L.

    2008-01-01

    A fire return intervals (FRI) for zone of larch dominance and ``larch-mixed taiga'' ecotone was studied. Extreme fire events were connected with summer air temperature deviations. Average FRI determined from stem fire scar dating was 82 +/- 7 years for the zone of larch dominance, and 77 +/- 20 for the ``larch-mixed taiga'' ecotone. For the zone of larch dominance FRI on north-east facing slopes was 86 +/- 11 years, for south-west facing slopes at 61 +/- 8 years, for flat terrain at 68 +/- 14 years, and for bogs 139 +/- 17 years. FRI decreased from 101 years in the 19th century to 65 years in the 20th century, for the zone of larch dominance, and from 97 years to 50 years for the ``larch-mixed taiga'' ecotone. A climate and anthropogenic impact on this phenomenon was analyzed. The decrease of FRI may interfere with climate-driven migration of competitor species into zone of larch dominance, affecting biodiversity at high latitudes.

  1. Inheritance of mitochondrial DNA in the conifer Larix.

    PubMed

    Deverno, L L; Charest, P J; Bonen, L

    1993-04-01

    Restriction fragment length polymorphisms between Larix leptolepis and Larix decidua were identified in heterologous hybridization experiments, using wheat mitochondrial DNA probes specific for atp9, coxI, nad3/rps12, and orf25. Analysis of eight individuals of each reciprocal hybrid of these two species revealed that mitochondrial DNA was maternally inherited. Furthermore, sequences homologous to wheat orf25 were also identified in Larix gmelini, Larix siberica, Larix olgensis, and Larix laricina, as well as Ginkgo biloba, Picea mariana, Picea glauca and Pinus contorta.

  2. Zn isotope fractionation in a pristine larch forest on permafrost-dominated soils in Central Siberia.

    PubMed

    Viers, Jerome; Prokushkin, Anatoly S; Pokrovsky, Oleg S; Kirdyanov, Alexander V; Zouiten, Cyril; Chmeleff, Jerome; Meheut, Merlin; Chabaux, Francois; Oliva, Priscia; Dupré, Bernard

    2015-01-01

    Stable Zn isotopes fractionation was studied in main biogeochemical compartments of a pristine larch forest of Central Siberia developed over continuous permafrost basalt rocks. Two north- and south-oriented watershed slopes having distinctly different vegetation biomass and active layer depth were used as natural proxy for predicting possible future climate changes occurring in this region. In addition, peat bog zone exhibiting totally different vegetation, hydrology and soil temperature regime has been studied. The isotopic composition of soil profile from Central Siberia is rather constant with a δ(66)Zn value around 0.2‰ close to the value of various basalts. Zn isotopic composition in mosses (Sphagnum fuscum and Pleurozium schreberi) exhibits differences between surface layers presenting values from 0.14 to 0.2‰ and bottom layers presenting significantly higher values (0.5 - 0.7‰) than the underlain mineral surface. The humification of both dead moss and larch needles leads to retain the fraction where Zn bound most strongly thus releasing the lighter isotopes in solution and preserving the heavy isotopes in the humification products, in general accord with previous experimental and modeling works [GCA 75:7632-7643, 2011]. The larch (Larix gmelinii) from North and South-facing slopes is enriched in heavy isotopes compared to soil reservoir while larch from Sphagnum peatbog is enriched in light isotopes. This difference may result from stronger complexation of Zn by organic ligands and humification products in the peat bog compared to mineral surfaces in North- and South-facing slope. During the course of the growing period, Zn followed the behavior of macronutrients with a decrease of concentration from June to September. During this period, an enrichment of larch needles by heavier Zn isotopes is observed in the various habitats. We suggest that the increase of the depth of rooting zone, and the decrease of DOC and Zn concentration in soil solution

  3. Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica

    PubMed Central

    Dulamsuren, Choimaa; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

    2010-01-01

    Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia’s forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140–490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century. PMID:20571829

  4. Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica.

    PubMed

    Dulamsuren, Choimaa; Hauck, Markus; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

    2010-08-01

    Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia's forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140-490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century.

  5. Long-term precommercial thinning effects on Larix occidentalis (western larch) tree and stand characteristics

    Treesearch

    Michael S. Schaedel; Andrew J. Larson; David L. R. Affleck; R. Travis Belote; John M. Goodburn; David K. Wright; Elaine Kennedy. Sutherland

    2017-01-01

    Precommercial thinning (PCT) is used to increase tree size and shorten harvest rotation time. Short-term results from PCT studies often show a trade-off between individual-tree growth and net stand yield, while longer-term effects of PCT on tree growth and stand yield are less well documented. We used a 54-year-old PCT study to test long-term effects of forest density...

  6. Tracing fresh assimilates through Larix decidua exposed to elevated CO₂ and soil warming at the alpine treeline using compound-specific stable isotope analysis.

    PubMed

    Streit, Kathrin; Rinne, Katja T; Hagedorn, Frank; Dawes, Melissa A; Saurer, Matthias; Hoch, Günter; Werner, Roland A; Buchmann, Nina; Siegwolf, Rolf T W

    2013-02-01

    How will carbon source-sink relations of 35-yr-old larch trees (Larix decidua) at the alpine treeline respond to changes in atmospheric CO(2) and climate? We evaluated the effects of previously elevated CO(2) concentrations (9 yr, 580 ppm, ended the previous season) and ongoing soil warming (4 yr, + 4°C). Larch branches were pulse labeled (50 at% (13)CO(2)) in July 2010 to trace fresh assimilates through tissues (buds, needles, bark and wood) and non-structural carbon compounds (NCC; starch, lipids, individual sugars) using compound-specific isotope analysis. Nine years of elevated CO(2) did not lead to increased NCC concentrations, nor did soil warming increase NCC transfer velocities. By contrast, we found slower transfer velocities and higher NCC concentrations than reported in the literature for lowland larch. As a result of low dilution with older carbon, sucrose and glucose showed the highest maximum (13)C labels, whereas labels were lower for starch, lipids and pinitol. Label residence times in needles were shorter for sucrose and starch (c. 2 d) than for glucose (c. 6 d). Although our treatments showed no persistent effect on larch carbon relations, low temperature at high altitudes clearly induced a limitation of sink activities (growth, respiration, root exudation), expressed in slower carbon transfer and higher NCC concentrations.

  7. L'Arche: Its Philosophy and Ideology.

    ERIC Educational Resources Information Center

    Sumarah, John

    1986-01-01

    The L'Arche movement in mental retardation based upon the work of J. Vanier stresses the value of the disabled person, the importance of mutual relationships, the importance of a sense of community, and the spiritual dimension. (CL)

  8. Spatial variations in larch needle and soil δ(15)N at a forest-grassland boundary in northern Mongolia.

    PubMed

    Fujiyoshi, Lei; Sugimoto, Atsuko; Tsukuura, Akemi; Kitayama, Asami; Lopez Caceres, M Larry; Mijidsuren, Byambasuren; Saraadanbazar, Ariunaa; Tsujimura, Maki

    2017-03-01

    The spatial patterns of plant and soil δ(15)N and associated processes in the N cycle were investigated at a forest-grassland boundary in northern Mongolia. Needles of Larix sibirica Ledeb. and soils collected from two study areas were analysed to calculate the differences in δ(15)N between needle and soil (Δδ(15)N). Δδ(15)N showed a clear variation, ranging from -8 ‰ in the forest to -2 ‰ in the grassland boundary, and corresponded to the accumulation of organic layer. In the forest, the separation of available N produced in the soil with (15)N-depleted N uptake by larch and (15)N-enriched N immobilization by microorganisms was proposed to cause large Δδ(15)N, whereas in the grassland boundary, small Δδ(15)N was explained by the transport of the most available N into larch. The divergence of available N between larch and microorganisms in the soil, and the accumulation of diverged N in the organic layer control the variation in Δδ(15)N.

  9. Growth-climate relations of Larix decidua and Pinus cembra in an inner-alpine dry valley

    NASA Astrophysics Data System (ADS)

    Obojes, Nikolaus; Meurer, Armin; Tasser, Erich; Mayr, Stefan; Oberhuber, Walter; Tappeiner, Ulrike

    2016-04-01

    Due to climate change, increasing temperatures and decreasing precipitation are expected for the southern part of the Alps. To estimate possible effects on growth conditions in mountain forests we investigated climate to tree growth relations along an elevation gradient in one of the driest regions in the Alps, the LTSER site Matsch/Mazia in South Tyrol, Italy. Besides Picea abies (27%), Larix decidua (42%) and Pinus cembra (25%) are the two most abundant tree species in the study area. While Pinus cembra is restricted to the sub-alpine zone, Larix decidua is ranging from the lowest parts of the study area up to the tree line, especially at lower elevations also due to reforestation efforts of heavily eroding pastures in the past 120 years and traditional silvopastural systems which promote Larch. The reaction of the two species to changing climatic conditions during the last 150 years were analyzed by relating tree ring width of Larix decidua from 8 sites at elevations from 1070 to 2430 m a.s.l. and of Pinus cembra from 5 sites ranging from 2030 to 2430 m a.s.l. at SE- and NW-exposed slopes to temperature and precipitation records from the nearby station at Marienberg (1310 m a.s.l.) dating back to 1860. Overall, basal area increment was highest at sites at about 2000 m a.s.l and decreased at higher and for Larch at lower sites. At lower elevations up to 1750 m a.s.l. growth rates of Larix decidua generally decreased during the last 15 years, especially during and after the 2003 heat wave, after increasing from the 1950s to the 1980s . On the contrary, at elevations of more than 2000 m a.s.l., growth of both Larch and Pinus cembra increased since the 1990s. Growth-climate correlations and extreme year analysis show a similar results: at low-elevation sites, growth was correlated positively to precipitation and reacted positively to wet and cold years and negatively to hot and dry years. On the other hand, growth was positively correlated to temperature at the

  10. Attraction of the gypsy moth to volatile organic compounds (VOCs) of damaged Dahurian larch.

    PubMed

    Li, Jing; Valimaki, Sanna; Shi, Juan; Zong, Shixiang; Luo, Youqing; Heliovaara, Kari

    2012-01-01

    Olfactory responses of the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae), a major defoliator of deciduous trees, were examined in Inner Mongolia, China. We studied whether the gypsy moth adults are attracted by the major volatile organic compounds (VOCs) of damaged Larix gmelinii (Dahurian larch) foliage and compared the attractiveness of the plant volatiles with that of the synthetic sex pheromone. Our results indicated that the VOCs of the Dahurian larch were effective in attracting gypsy moth males especially during the peak flight period. The VOCs also attracted moths significantly better than the sex pheromone of the moth. Our study is the first trial to show the responses of adult gypsy moths to volatile compounds emitted from a host plant. Electroantennogram responses of L. gmelinii volatiles on gypsy moths supported our field observations. A synergistic effect between host plant volatiles and sex pheromone was also obvious, and both can be jointly applied as a new attractant method or population management strategy of the gypsy moth.

  11. Magnesium isotopes in permafrost-dominated Central Siberian larch forest watersheds

    NASA Astrophysics Data System (ADS)

    Mavromatis, Vasileios; Prokushkin, Anatoly S.; Pokrovsky, Oleg S.; Viers, Jérôme; Korets, Mikhail A.

    2014-12-01

    To unravel the Mg isotope fractionation pathways within the continuous permafrost zone in the larch deciduous forest of Central Siberia, we measured the Mg isotopic composition of two large Siberian rivers (Nizhnaya Tunguska and Kochechum, which flow into the Yenisey), a small forested stream, and the major fluid and solid sources of Mg in the watershed: atmospheric precipitates, surface suprapermafrost flow, interstitial soil solutions, plant biomass, litter and mineral soils. The obtained results indicate a significant seasonal variation in riverine water Mg isotope signatures. During the winter baseflow, the Mg isotope composition of large rivers is significantly lighter than the source basaltic rocks and the atmospheric depositions. These differences support the presence of fluids enriched in lighter Mg isotopes, such as those affected by the mineral precipitation of secondary silicates or fluids that dissolve sedimentary carbonate rocks. During the spring flood and in the summer and fall seasons, the river fluid δ26Mg values increased by 0.2-0.3‰ and approached the Mg isotope composition of the ground vegetation (dwarf shrubs, mosses) and the soil organic horizon. Overall, the riverine waters were 0.3-0.7‰ lighter than the unaltered bedrock and the deep minerals soil horizons. The Mg isotopic compositions of Larix gmelinii organs (i.e., stem wood, roots and needles) exhibit a low variability. However, an enrichment of 0.2-0.3‰ in the δ26Mg of larch needles in the course of the growing season, from June to September can be observed. This enrichment most likely demonstrates uptake of isotopically heavier Mg by the plant in addition to the progressive thawing of the mineral soil (deepening of the active layer of the soil). Overall, the Mg isotope approach indicates the important contribution of vegetation (larch needles, mosses and dwarf shrubs) to the riverine Mg isotope signature and helps to reveal the contribution of isotopically light carbonate rocks

  12. Genetic aftereffects of increased temperature in Larix

    Treesearch

    Michael S. Greenwood; Keith W. Hutchinson

    1996-01-01

    We tested the hypothesis that temperature during gametogenesis and embryogenesis can affect progeny genotype and phenotype. Identical crosses were made among cloned parents of Larix spp. inside and outside a greenhouse, where the temperature inside averaged 4?C above the outside temperature. Significant growth differences as a function of crossing...

  13. Isolation, characterization and expression analysis of the BABY BOOM (BBM) gene from Larix kaempferi × L. olgensis during adventitious rooting.

    PubMed

    Li, Kui-Peng; Sun, Xiao-Mei; Han, Hua; Zhang, Shou-Gong

    2014-11-10

    The full-length cDNA and genomic sequences of the BABY BOOM (BBM) gene, designated LkBBM, were isolated from Larix kaempferi × Larix olgensis. The 3324 bp cDNA was cloned and its open reading frame (ORF) consists of 2370 nucleotides. The deduced 789 amino acid protein contains two AP2 domains and a BBM specific motif. Four conserved motifs between BBM and PLT were identified, which may be conducive to the similar function of BBM and PLT. The three dimensional (3D) structure of LkBBM was predicted and β-sheets in the AP2-R2 domain of LkBBM might recognize the specific base pairs in the major groove. Analysis of the LkBBM gene structure indicates that the gene has eight introns and nine exons. In the 5'-flanking promoter region of LkBBM, many important potential cis-acting elements were identified, such as the TATABOX5 element (a functional TATA element), ROOTMOTIFTAPOX1 element (element of root specificity), AUXREPSIAA4 element (element involved in auxin responsiveness and gene expression in root meristem), MYB1AT element (element involved in MYB recognition), ARR1AT element (element involved in cytokinin responsiveness), GARE1OSREP1 element (element involved in gibberellin responsiveness) and PYRIMIDINEBOXHVEPB1 element (element involved in abscisic acid responsiveness), which all suggested that the expression of LkBBM is highly regulated. Compared with gene expression levels in the stem, stem tip and leaf, LkBBM shows a specific expression in the root, which indicates that LkBBM plays a key role in regulating the development and growth of root in larch. In the processing of larch adventitious root formation, LkBBM started to express on the eighth day after rooting treatment and its transcript level increased continuously afterwards. According to the gene characteristics, LkBBM is proposed as a molecular marker for root primordia of larch, and the initial period of LkBBM expression may be the formation period of root primordia in the processing of adventitious

  14. [Seasonal development of phloem in Siberian larch stems].

    PubMed

    Antonova, G F; Stasova, V V

    2008-01-01

    The seasonal development of phloem in the stems of Siberian larch (Larix sibirica Ldb.) was studied over two seasons on 50-60-year-old trees growing in a natural stand in the Siberian forest-steppe zone. Trees at the age of 20-25 years were used to study metabolites in differentiating and mature phloem elements, cambial zone, and radially growing xylem cells in the period of early and late wood formation. The development of the current-year phloem in the stems of 50-60-year-old trees started, depending on climatic conditions, in the second-third decades of May, 10-20 days before the xylem formation, and ended together with the shoot growth cessation in late July. Monitoring of the seasonal activity of cambium producing phloem sieve cells and the duration of their differentiation compared to the xylem derivatives in the cambium demonstrated that the top production of phloem and xylem cells could coincide or not coincide during the season, while their differentiation activity was always in antiphase. Sieve cells in the early phloem are separated from those in the late phloem by a layer of tannin-containing cells, which are formed in the period when late xylem formation starts. The starch content in the structural elements of phloem depends on the state of annual xylem layer development. The content of low molecular weight carbohydrates, amino acids, organic acids, and phenols in phloem cells, cambial zone, and xylem derivatives of the cambium depends on the cell type and developmental stage as well as on the type of forming wood (early or late) differing by the cell wall parameters and, hence, by the requirement for assimilates. Significant differences in the dynamics of substances per dry weight and cell were observed during cell development.

  15. Recovery of snow-bent young western larch

    Treesearch

    Wyman C. Schmidt; Jack A. Schmidt

    1979-01-01

    This paper illustrates how much, how long it takes, and the method in which young western larch responds to snow bend. A 13-year-old vigorous larch stand was flattened by a heavy, wet snow in June 1966 in northwestern Montana. We recorded photographically how two different crown classes (dominant and nondominant) of young larch subjected to four levels of snow beud (...

  16. Resin duct size and density as ecophysiological traits in fire scars of Pseudotsuga menziesii and Larix occidentalis

    PubMed Central

    Arbellay, Estelle; Stoffel, Markus; Sutherland, Elaine K.; Smith, Kevin T.; Falk, Donald A.

    2014-01-01

    Background and Aims Resin ducts (RDs) are features present in most conifer species as defence structures against pests and pathogens; however, little is known about RD expression in trees following fire injury. This study investigates changes in RD size and density in fire scars of Douglas fir (Pseudotsuga menziesii) and western larch (Larix occidentalis) as a means to evaluate the ecophysiological significance of traumatic resinosis for tree defence and survival. Methods Transverse and tangential microsections were prepared for light microscopy and image analysis in order to analyse axial and radial RDs, respectively. Epithelial cells of RDs and fusiform rays associated with radial RDs were also examined. RDs were compared between normal xylem and wound xylem at four different section heights along the fire-injured stem. Key Results Following fire injury, P. menziesii axial RDs narrowed by 38–43 % in the first year after injury, and the magnitude of this change increased with stem height. Larix occidentalis axial RDs widened by 46–50 % in the second year after injury. Radial RDs were of equivalent size in P. menziesii, but widened by 162–214 % in L. occidentalis. Fusiform rays were larger following fire injury, by 4–14 % in P. menziesii and by 23–38 % in L. occidentalis. Furthermore, axial RD density increased in both species due to the formation of tangential rows of traumatic RDs, especially in the first and second years after injury. However, radial RD density did not change significantly. Conclusions These results highlight traumatic resinosis as a species-specific response. Pseudotsuga menziesii produce RDs of equivalent or reduced size, whereas L. occidentalis produce wider RDs in both the axial and radial duct system, thereby increasing resin biosynthesis and accumulation within the whole tree. Larix occidentalis thus appears to allocate more energy to defence than P. menziesii. PMID:25122653

  17. Wildfires in Northern Siberian Larch Dominated Communities

    NASA Technical Reports Server (NTRS)

    Khaurk, Viacheslav I.; Ranson, Kenneth J.; Dvinskaya, Maria L.; Im, Sergey T.

    2011-01-01

    The fire history of the northern larch forests within the permafrost zone in a portion of northern Siberia (approx 66 deg N, 100 deg E) was studied. Since there is little to no human activities in this area fires within the study area were mostly caused by lightning. Fire return intervals (FRI) were estimated based on burn marks on tree stems and dates of tree natality. FRI values varied from 130 yr to 350 yr with 200 +/- 50 yr mean. In southerly larch dominated communities FRI was found to be shorter (77 +/- 20 yr at approx 61 deg. N, and 82 +/- 7 at 64 deg N), and longer at the northern boundary (approx 71 deg) of larch stands (320 +/- 50 yr). During the Little Ice Age period in the 16th to 18th centuries FRI was approximately twice as long as recorded in this study. Fire caused changes in the soil including increases in soil drainage and permafrost thawing depth and a radial growth increase of about 2 times (with more than 6 times observed). This effect may simulate the predicted warming impact on the larch growth in the permafrost zone.

  18. Toxicity of aerosols to larch casebearer larvae

    Treesearch

    Robert L. Lyon; Margaret E. May

    1970-01-01

    Six insecticides were tested in the laboratory as aerosols against larch casebeare1 larvae. Their toxicity was determined by both direct contact and residual contact on filter paper. All six were highly toxic at less than 1.05 µg/ cm2 (the equivalent of 1.5 oz./acre). In decreasing order of toxicity at LD90 (direct contact...

  19. Carbon and nitrogen status of litterfall, litter decomposition and soil in even-aged larch, red pine and rigitaeda pine plantations.

    PubMed

    Kim, Choonsig; Jeong, Jaeyeob; Cho, Hyun-Seo; Son, Yowhan

    2010-07-01

    The carbon (C) and nitrogen (N) status in forest ecosystems can change upon establishment of plantations because different tree species have different nutrient cycling mechanisms. This study was carried out to evaluate C and N status of litterfall, litter decomposition and soil in three adjacent plantations consisting of one deciduous (larch: Larix leptolepis) and two evergreen (red pine: Pinus densiflora; rigitaeda pine: P. rigida x P. taeda) species planted in the same year (1963). Both the pine plantations showed comparatively higher C input from needle litter but significantly lower N concentration and input than the larch plantation (P < 0.05). During the decomposition process, the deciduous larch needle litter showed low C concentration and C remaining in soil, but high N concentration and N remaining in soil compared to the two evergreen pine needle litters. However, the soil C and N concentration and their content at a soil depth of 0-10 cm were not affected significantly (P > 0.05) by the plantation type. These results demonstrate the existence of considerable variation in C and N status resulting from needle litter input and litter decomposition in these three plantations grown at sites with similar environmental conditions.

  20. Analysis of genetic diversity in Larix gmelinii (Pinaceae) with RAPD and ISSR markers.

    PubMed

    Zhang, L; Zhang, H G; Li, X F

    2013-01-24

    Dahurian larch (Larix gmelinii), a deciduous conifer, is the northernmost tree, native to eastern Siberia and nearby regions of China. We used growth traits and molecular markers to assess genetic variation in different L. gmelinii growing regions; 105 individual samples were collected from seven regions of the Qingshan Forestry Centre, Heilongjiang Province, China. The greatest genetic regional variation was seen in the Youhao area, based on coefficients of variation for tree height, diameter and volume (14.73, 28.25, and 55.27%, respectively). Analysis using molecular markers showed rich genetic diversity. The RAPD and ISSR methods both indicated that most variation came from within populations. The seven regions were divided into two groups (Daxing'an and Xiaoxing'an Mountain ranges) by RAPD cluster analysis: Tianchi, Xiaojiuya, Yuanjiang, and Taiping regions were placed in the first group at a genetic distance of 0.08; while the other regions were in the second group. The correlation between RAPD markers and geographical distance was significant, with a correlation coefficient of 0.752.

  1. Effect of waterlogging on carbon isotope discrimination during photosynthesis in Larix gmelinii.

    PubMed

    Li, Fang; Sugimoto, Atsuko

    2017-08-06

    Soil moisture is a major factor controlling carbon isotope discrimination (Δ(13)C), which has been demonstrated to decrease under dry conditions in many studies; however, few studies on Δ(13)C under waterlogging condition have been conducted. In this study, a pot experiment was conducted with Larix gmelinii, a major larch species in the east Siberian Taiga, to investigate the effect of waterlogging on Δ(13)C during photosynthesis. Assimilation rate and Δ(13)CRD (instantaneous Δ(13)C calculated with Rayleigh distillation equation) decreased drastically soon after waterlogging, followed by recovery in their values, which was caused by a change in stomatal conductance. Thereafter, assimilation rate decreased gradually, whereas Δ(13)CRD decreased more gently. These results were thought to be caused by the decrease in both stomatal conductance and carboxylation. Our results indicate that extreme wet events may cause a decrease in Δ(13)C, which is important information for detecting flooding events in the past using tree-ring isotope analyses and for studying impacts of flooding on plants in areas where waterlogging might occur.

  2. Climate effects on inter- and intra-annual larch stemwood anomalies in the Mongolian forest-steppe

    NASA Astrophysics Data System (ADS)

    Khishigjargal, Mookhor; Dulamsuren, Choimaa; Leuschner, Hanns Hubert; Leuschner, Christoph; Hauck, Markus

    2014-02-01

    Climate response of tree-ring width and intra-annual wood anomalies were studied in stands of Siberian larch (Larix sibirica) on Mt. Bogd Uul in the forest-steppe ecotone of Mongolia. Climate on Mt. Bogd Uul is characterized by an increase of the annual mean temperature by 1.5 K between 1965 and 2007, the lack of a long-term trend for annual precipitation and, with it, an increase in aridity. Tree-ring width increases with increasing June precipitation of the current year (June) and increasing late summer precipitation of the previous year. In >100-year old trees, also a negative correlation of tree-ring width with the July temperature of the year prior to tree-ring formation was found. Decreasing tree-ring width with increasing snowfall in December can be explained with the protection of the frost-sensitive eggs of gypsy moth by snow cover, which is a major herbivore of larch in Mongolia and causes reduction in the annual stem increment. The most significant change in wood anatomy was the decline of wide latewood, which is attributable to the increase of summer days with a mean temperature > 15 °C and drought periods in summer without precipitation. Increasing summer drought is also thought to have caused the repeated occurrence of missing rings since the 1960s, which were not observed in the late 19th and early 20th centuries.

  3. Maturation in Larch : II. Effects of Age on Photosynthesis and Gene Expression in Developing Foliage.

    PubMed

    Hutchison, K W; Sherman, C D; Weber, J; Smith, S S; Singer, P B; Greenwood, M S

    1990-11-01

    The effect of maturation on the morphological and photosynthetic characteristics, as well as the expression of two genes involved in photosynthesis in the developing, current year foliage of Eastern larch (Larix laricina [Du Roi]) is described. These effects were observed on foliage during the third growing season after grafting of scions from trees of different ages onto 2 year old rootstock. Specific leaf weight (gram dry weight per square meter), leaf cross-sectional area (per square millimeter), and chlorophyll content (milligram per gram dry weight) all increase with increasing age in long shoot foliage from both indoor- and outdoor-grown trees. Net photosynthesis (NPS) (mole of CO(2) per square millimeter per second) increases with age on indoor- but not outdoor-grown trees. NPS also increases with increased chlorophyll content, but outdoor-grown scions of all ages had higher chlorophyll content, and chlorophyll does not appear to be limiting for NPS outdoors. To extend these studies of maturation-related differences in foliar morphology and physiology to the molecular genetic level, sequences were cloned from the cab and rbsS gene families of larch. Both cab and rbcS gene families are expressed in foliage but not in roots, and they are expressed in light-grown seedlings of larch but only at very low levels in dark-grown seedlings (~2% of light-grown seedlings). Steady-state cab mRNA levels are relatively higher (~40%) in newly expanding short shoot foliage from juvenile plants compared to mature plants. Unlike cab, the expression of the rbcS gene family did not seem to vary with age. These data show that the maturation-related changes in morphological and physiological phenotypes are associated with changes in gene expression. No causal relationship has been established, however. Indeed, we conclude that the faster growth of juvenile scions reported previously (MS Greenwood, CA Hopper, KW Hutchison [1989] Plant Physiol 90: 406-412) is not due to increased

  4. Characterization of Siberia Larch Forest from Palsar L-Band Radar and Landsat Vcf Data Trained by High-Resolution Stereo and Field Data

    NASA Astrophysics Data System (ADS)

    Ranson, J.; Sun, G.; Montesano, P. M.; Cook, B. D.

    2014-12-01

    Larch (Larix spp.) dominant forests occupy about 70% of the permafrost areas in Siberia. Improved understanding of the fate of the larch forests in the face of climate change requires a concerted long term research effort to detect and quantify ecosystem responses. Satellite data analysis offers much improved information on changes in the forest-tundra transitional zone and on forest structure in this area. The LANDSAT data and radar data such as ALOS/PALSAR provide extensive coverage at high resolution (30m pixel). In this study, the utilization of these data for regional canopy height and biomass mapping was examined. The major challenge for characterization of forest in a remote area such as Siberia is the lack of adequate number of training and validation data. The results of using GLAS waveform data to extend field measurements which has been successful in other ecosystems were found to be poor because most of the waveforms were acquired when the deciduous larch tree had no needles. In this study, the stereo optical data from high resolution spaceborne imagery (HRSI) were used to a generate canopy height model (CHM) by identifying both tree top and ground surface in these sparse forests. The regression models between the field measured canopy height, biomass and the stereo CHM were developed and the field data were extended to the forested areas within the entire stereo images, providing more data for training and validation. We compare the mapping results from two methods. One uses GLAS waveform data and the other uses high resolution stereo imagery to extrapolate field measurements. Results demonstrate the potential and limitations using high resolution stereo imagery to provide training information of sparse larch forest in Siberia.

  5. Maturation in larch : I. Effect of age on shoot growth, foliar characteristics, and DNA methylation.

    PubMed

    Greenwood, M S; Hopper, C A; Hutchison, K W

    1989-06-01

    The time course of maturation in eastern larch (Larix laricina [Du Roi] K. Koch) was examined by grafting scions from trees of different ages onto 2-year-old root stock and following scion development for several years. Height, diameter, foliar chlorophyll content, and rooting ability of scion-derived cuttings all varied linearly as a function of log(10) age. Chlorophyll content (milligrams per gram of dry weight) increased while height, diameter, and ability to root decreased with age (P < 0.01). The tendency toward orthotropic growth and branch formation per centimeter of main stem decreased abruptly between age 1 and 5 years (P < 0.01). Total chlorophyll content of both long and short shoot foliage increased by 30 to 50% with increasing age, but the chlorophyll a/b ratio did not change. Also, juvenile long shoot needles were significantly longer than mature (P < 0.01). Surprisingly, the juvenile scions produced more total strobili over two successive years, but the mature scions produced a significantly higher proportion of male strobili (P < 0.001 year 1; P < 0.02 year 2). The age-related changes in foliar traits were not associated with changes in DNA methylation between juvenile and mature scions. Using HPLC, we found that 20% of foliar DNA cytosine residues were methylated in both scion types.

  6. Tissue-Specific and Development-Dependent Accumulation of Phenylpropanoids in Larch Mycorrhizas.

    PubMed Central

    Weiss, M.; Mikolajewski, S.; Peipp, H.; Schmitt, U.; Schmidt, J.; Wray, V.; Strack, D.

    1997-01-01

    The tissue-specific and development-dependent accumulation of secondary products in roots and mycorrhizas of larch (Larix decidua Mill.; Pinaceae) was studied using high-performance liquid chromatography and histochemical methods. The compounds identified were soluble catechin, epicatechin, quercetin 3-O-[alpha]-rhamnoside, cyanidin- and peonidin 3-O-[beta]-glucoside, 4-O-[beta]-hydroxybenzoyl-O-[beta]-glucose, 4-hydroxybenzoate 4-O-[beta]-glucoside, maltol 3-O-[beta]-glucoside, and the wall-bound 4-hydroxybenzaldehyde, vanillin, and ferulate. In addition, we partially identified a tetrahydroxystilbene monoglycoside, a quercetin glycoside, and eight oligomeric proanthocyanidins. Comparison between the compounds accumulating in the apical tissue of fine roots, long roots, and in vitro grown mycorrhizas (L. decidua-Suillus tridentinus) showed elevated levels of the major compounds catechin and epicatechin as well as the minor compound 4-hydroxybenzoate 4-O-[beta]-glucoside specifically in the root apex of young mycorrhizas. The amounts of wall-bound 4-hydroxybenzaldehyde and vanillin were increased in all of the mycorrhizal sections examined. During the early stages of mycorrhization the concentrations of these compounds increased rapidly, perhaps induced by the mycorrhizal fungus. In addition, studies of L. decidua-Boletinus cavipes mycorrhizas from a natural stand showed that the central part of the subapical cortex tissue and the endodermis both accumulate massive concentrations of catechin, epicatechin, and wall-bound ferulate compared with the outer part of the cortex, where the Hartig net is being formed. PMID:12223686

  7. Internal transcribed spacer region evolution in Larix and Pseudotsuga (Pinaceae).

    PubMed

    Gernandt, D S; Liston, A

    1999-05-01

    The nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region has been characterized in the sister genera Larix and Pseudotsuga (Pinaceae). Complete sequences were obtained for seven species of Larix from North America and Eurasia and five species of Pseudotsuga from western North America and eastern Asia. ITS region lengths ranged from 1759 to 1770 bp in Larix and from 1564 to 1571 bp in Pseudotsuga. In both genera, ITS1 is three times as long as the 5.8S plus ITS2 and contains subrepeats as observed in other genera of Pinaceae. Secondary structure models predicted that the subrepeats fold into terminal stem and loop domains. ITS polymorphism detected within individuals of Larix and Pseudotsuga suggests a slow rate of concerted evolution among nrDNA loci. Except for the placement of L. sibirica, phylogenetic analyses of the ITS region agreed with previously reported restriction site analyses of Larix and Pseudotsuga. The data were not consistent with phylogenetic hypotheses for Larix based primarily upon ovulate cone characters, failing to support a derivation of the North American L. laricina from a short-bracted Eurasian lineage. The phylogenetic hypothesis did not conflict with a stepping stone model of evolution for Pseudotsuga, but a basal lineage could not be inferred for either genus.

  8. Tree Line Structure and Dynamics at the Northern Limit of the Larch Forest: Anabar Plateau, Siberia, Russia

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Ranson, Kenneth J.; Im, Sergey T.; Oskorbin, Pavel A.; Dvinskaya, Maria L.; Ovchinnikov, Dmitriy V.

    2013-01-01

    The goal of the study was to provide an analysis of climate impact before, during, and after the Little Ice Age (LIA) on the larch (Larix gmelinii) tree line at the northern extreme of Siberian forests. Recent decadal climate change impacts on the tree line, regeneration abundance, and age structure were analyzed. The location of the study area was within the forest-tundra ecotone (elevation range 170-450 m) in the Anabar Plateau, northern Siberia. Field studies were conducted along elevational transects. Tree natality/mortality and radial increment were determined based on dendrochronology analyses. Tree morphology, number of living and subfossil trees, regeneration abundance, and age structure were studied. Locations of pre-LIA, LIA, and post-LIA tree lines and refugia boundaries were established. Long-term climate variables and drought index were included in the analysis. It was found that tree mortality from the 16th century through the beginning of the 19th century caused a downward tree line recession. Sparse larch stands experienced deforestation, transforming into tundra with isolated relict trees. The maximum tree mortality and radial growth decrease were observed to have occurred at the beginning of 18th century. Now larch, at its northern boundary in Siberia, is migrating into tundra areas. Upward tree migration was induced by warming in the middle of the 19th century. Refugia played an important role in repopulation of the forest-tundra ecotone by providing a seed source and shelter for recruitment of larch regeneration. Currently this ecotone is being repopulated mainly by tree cohorts that were established after the 1930s. The last two decades of warming did not result in an acceleration of regeneration recruitment because of increased drought conditions. The regeneration line reached (but did not exceed) the pre-LIA tree line location, although contemporary tree heights and stand densities are comparatively lower than in the pre-LIA period. The mean

  9. Age-related trends in genetic parameters for Larix kaempferi and their implications for early selection

    PubMed Central

    2014-01-01

    Background Japanese larch (Larix kaempferi) has been introduced in China at the end of the 19th century, and as one successful exotic species, is becoming the preferred coniferous in northern China and sub-tropical alpine region. The rotation age is about 25-28 years for L. kaempferi as pulpwood in Henan province. Waiting for even one-half rotation age for final evaluation will be inefficient due to accumulated testing costs and delayed return on investment, which suggests that selection at an early age is highly desirable for L. kaempferi improvement programs in Henan province. In this study, we determined age trends of genetic parameters and evaluated early selection efficiency for L. kaempferi in Henan province to find out the appropriate trait for early selection and its selection age. Results Growth traits of 78 clones were measured periodically from age 2 to age 15 in a clonal trial of Larix kaempferi establishted at Son town, Henan Province. The genetic variation among clones, age-age correlations, and age trends in genetic parameters for growth traits were analyzed. Variant analysis revealed that tree height (HGT) and diameter at breast (DBH) were significant (1% level) among clones at every ages. The clonal repeatability of growth traits varied year-by-year, reaching the highest levels at different ages for different traits (0.77 at age 2 for HGT, 0.70 at age 5 for DBH and 0.66 from age 8 to age 10 for volume, respectively). The age-age genetic correlations ranged from 0.904 to 1.000 for HGT, and from 0943 to 1.000 for DBH. DBH at different ages was more genetically correlated to volume-15 than HGT. At the phenotypic level, HGT was always less correlated to volume-15 than DBH. With the estimates of efficiencies of early selection, the recommendation from present study was that the optimum age of early selection was age 2 for HGT and age 5 for DBH. Conclusions Our study showed that there were significant (1% level) on growth traits among clones at every

  10. Larch: An Analysis Package for XAFS and Related Spectroscopies

    NASA Astrophysics Data System (ADS)

    Newville, Matthew

    2013-04-01

    LARCH, a package of analysis tools for XAFS and related spectroscopies is presented. A complete rewrite of the ifeffit package, the initial release of larch preserves the core XAFS analysis procedures such as normalization, background subtraction, Fourier transforms, fitting of XANES spectra, and fitting of experimental spectra to a sum of feff Paths, with few algorithmic changes made in comparison to IFEFFIT. LARCH is written using Python and its packages for scientific programming, which gives significant improvements over IFEFFIT in the ability to handle multi-dimensional and large data sets, write complex analysis scripts, visualize data, add new functionality, and customize existing capabilities. Like the earlier version, larch can run from an interactive command line or in batch-mode, but larch can also be run as a server and accessed from clients using standard inter-process communication techniques available in a variety of computer languages. larch is freely available under an open source license. Examples of using larch are shown, future directions for development are discussed, and collaborations for adding new capabilities are actively sought.

  11. Wildfires Dynamics in Siberian Larch Forests

    NASA Technical Reports Server (NTRS)

    Ponomarev, Evgenii I.; Kharuk, Viacheslav I.; Ranson, Kenneth J.

    2016-01-01

    Wildfire number and burned area temporal dynamics within all of Siberia and along a south-north transect in central Siberia (45deg-73degN) were studied based on NOAA/AVHRR (National Oceanic and Atmospheric Administration/ Advanced Very High Resolution Radiometer) and Terra/MODIS (Moderate Resolution Imaging Spectroradiometer) data and field measurements for the period 1996-2015. In addition, fire return interval (FRI) along the south-north transect was analyzed. Both the number of forest fires and the size of the burned area increased during recent decades (p < 0.05). Significant correlations were found between forest fires, burned areas and air temperature (r = 0.5) and drought index (The Standardized Precipitation Evapotranspiration Index, SPEI) (r = 0.43). Within larch stands along the transect, wildfire frequency was strongly correlated with incoming solar radiation (r = 0.91). Fire danger period length decreased linearly from south to north along the transect. Fire return interval increased from 80 years at 62 N to 200 years at the Arctic Circle (6633' N), and to about 300 years near the northern limit of closed forest stands (about 71+ N). That increase was negatively correlated with incoming solar radiation (r = 0.95). Keywords: wildfires; drought index; larch stands; fire return interval; fire frequency; burned area; climate-induced trends in Siberian wildfires

  12. Comparison of CO2 fluxes in a larch forest on permafrost and a pine forest on non-permafrost soils in Central Siberia

    NASA Astrophysics Data System (ADS)

    Zyryanov, V.; Tchebakova, N. M.; Nakai, Y.; Zyryanova, O.; Parfenova, E. I.; Matsuura, Y.; Vygodskaya, N.

    2013-12-01

    Inter-annual and seasonal variations of energy, water and carbon fluxes and associated climate variables in a middle taiga pine (Pinus sylvestris) forest on warm sandy soils and a northern taiga larch (Larix gmelini) forest on permafrost in Central Siberia were studied from eddy covariance measurements obtained during growing seasons of 1998-2000 and 2004-2008 (except 2006) respectively. Both naturally regenerated after fire forests grew in different environments and differed by their tree stand characteristics. The pure Gmelin larch stand was 105 yr old, stem density of living trees was about 5480 trees/ha, LAI was 0.6 m2/m2, biomass (dry weight) was 0.0044 kg/m2, with average diameter of the trees at breast height 7.1 cm and mean tree height 6.8 m. The pure Scots pine stand was 215 yr old, stand structure was relatively homogenous with a stem density of 468 living trees/ha, LAI was 1.5 m2/m2, biomass (dry weight) was 10.7 kg/m2, with average diameter of the trees at breast height 28 cm and mean tree height 23 m. The climatic and soil conditions of these ecosystems were very distinctive. The habitat of the larch forest was much colder and dryer than that of the pine forest: the growing season was 1 month shorter and growing-degree days 200°C less and winters were about one month longer and colder with January temperature -37°C versus -23°C; annual precipitation was 400 mm in the larch versus 650 mm in the pine forest and maximal snow pack was 40 cm vs 70 cm. The soils were Gelisols with permafrost table within the upper 1 m in the larch stand and Pergelic Cryochrept, alluvial sandy soil with no underlying permafrost. Average daily net ecosystem exchange (NEE) was significantly smaller in the larch ecosystem - (-3-6) μmol/m2s compared to that in the pine forest (-7-8) μmol/m2s, however daily maximal NEE was about the same. Seasonal NEE in the larch forest on continuous permafrost varied from -53 to -107 and in the pine forest on non-permafrost from -180 to

  13. Maturation, topophysis and other factors in relation to rooting in Larix.

    PubMed

    Peer, K R; Greenwood, M S

    2001-03-01

    We examined effects of mist quantity, topophysis (origin of cutting in the crown of 6-year-old trees), maturation state of the donor stock, and time of sticking on rooting and root system quality of cuttings representing five full-sib hybrid larch families obtained with Larix decidua Mill., L. laricina (du Roi) K. Koch, and L. kaempferi (Lamb.) Sarg. (Sieb. and Zucc.) Gord., as parents. Mist frequency, supplemental watering and family all had highly significant effects on percentage of cuttings rooting and root system quality. The high-frequency misting regime yielded both higher rooting percentages and higher quality root systems than the low-frequency regime without supplemental watering. Supplemental watering of the rooting medium in the low-frequency misting regime increased both percent rooting and root system quality to values comparable with those obtained by cuttings in the high-frequency misting regime. Rooting of cuttings from the top, middle and bottom whorls of 5-year-old plantation grown trees tended to decline with increasing height for three of the five families. Overall, height of cutting origin did not significantly affect rooting, but when analyzed separately, two families exhibited a significant decline in rooting toward the top of the trees. Age of donor ortet (ranging from 1 to 7 years) significantly affected both percent rooting and root system quality. Rooting percentages declined linearly with age, and root system quality declined more sharply than percent rooting. The relatively poor root system quality of cuttings from ortets older than 1 year was closely associated with plagiotropic growth. Softwood cuttings (stuck in mid-July) rooted better than hardwood cuttings (stuck in early September) across all families.

  14. Relationships between root respiration rate and root morphology, chemistry and anatomy in Larix gmelinii and Fraxinus mandshurica.

    PubMed

    Jia, Shuxia; McLaughlin, Neil B; Gu, Jiacun; Li, Xingpeng; Wang, Zhengquan

    2013-06-01

    Tree roots are highly heterogeneous in form and function. Previous studies revealed that fine root respiration was related to root morphology, tissue nitrogen (N) concentration and temperature, and varied with both soil depth and season. The underlying mechanisms governing the relationship between root respiration and root morphology, chemistry and anatomy along the root branch order have not been addressed. Here, we examined these relationships of the first- to fifth-order roots for near surface roots (0-10 cm) of 22-year-old larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) plantations. Root respiration rate at 18 °C was measured by gas phase O2 electrodes across the first five branching order roots (the distal roots numbered as first order) at three times of the year. Root parameters of root diameter, specific root length (SRL), tissue N concentration, total non-structural carbohydrates (starch and soluble sugar) concentration (TNC), cortical thickness and stele diameter were also measured concurrently. With increasing root order, root diameter, TNC and the ratio of root TNC to tissue N concentration increased, while the SRL, tissue N concentration and cortical proportion decreased. Root respiration rate also monotonically decreased with increasing root order in both species. Cortical tissue (including exodermis, cortical parenchyma and endodermis) was present in the first three order roots, and cross sections of the cortex for the first-order root accounted for 68% (larch) and 86% (ash) of the total cross section of the root. Root respiration was closely related to root traits such as diameter, SRL, tissue N concentration, root TNC : tissue N ratio and stele-to-root diameter proportion among the first five orders, which explained up to 81-94% of variation in the rate of root respiration for larch and up to 83-93% for ash. These results suggest that the systematic variations of root respiration rate within tree fine root system are possibly due to the

  15. Higher climate warming sensitivity of Siberian larch in small than large forest islands in the fragmented Mongolian forest steppe.

    PubMed

    Khansaritoreh, Elmira; Dulamsuren, Choimaa; Klinge, Michael; Ariunbaatar, Tumurbaatar; Bat-Enerel, Banzragch; Batsaikhan, Ganbaatar; Ganbaatar, Kherlenchimeg; Saindovdon, Davaadorj; Yeruult, Yolk; Tsogtbaatar, Jamsran; Tuya, Daramragchaa; Leuschner, Christoph; Hauck, Markus

    2017-09-01

    Forest fragmentation has been found to affect biodiversity and ecosystem functioning in multiple ways. We asked whether forest size and isolation in fragmented woodlands influences the climate warming sensitivity of tree growth in the southern boreal forest of the Mongolian Larix sibirica forest steppe, a naturally fragmented woodland embedded in grassland, which is highly affected by warming, drought, and increasing anthropogenic forest destruction in recent time. We examined the influence of stand size and stand isolation on the growth performance of larch in forests of four different size classes located in a woodland-dominated forest-steppe area and small forest patches in a grassland-dominated area. We found increasing climate sensitivity and decreasing first-order autocorrelation of annual stemwood increment with decreasing stand size. Stemwood increment increased with previous year's June and August precipitation in the three smallest forest size classes, but not in the largest forests. In the grassland-dominated area, the tree growth dependence on summer rainfall was highest. Missing ring frequency has strongly increased since the 1970s in small, but not in large forests. In the grassland-dominated area, the increase was much greater than in the forest-dominated landscape. Forest regeneration decreased with decreasing stand size and was scarce or absent in the smallest forests. Our results suggest that the larch trees in small and isolated forest patches are far more susceptible to climate warming than in large continuous forests pointing to a grim future for the forests in this strongly warming region of the boreal forest that is also under high land use pressure. © 2017 John Wiley & Sons Ltd.

  16. Homogeneous genetic structure and variation in tree architecture of Larix kaempferi along altitudinal gradients on Mt. Fuji.

    PubMed

    Nishimura, Masao; Setoguchi, Hiroaki

    2011-03-01

    Variations in tree architecture and in the genetic structure of Larix kaempferi on Mt. Fuji were surveyed along altitudinal gradients using 11 nSSR loci. In total, 249 individuals from six populations along three trails at altitudes ranging from approximately 1,300 to 2,700 m were investigated. Gradual changes in tree architecture with increasing elevation, from erect trees to flag trees and krummholz mats, were observed in the high-altitude populations (> 2,000 m) on all trails. These findings suggest that tree architecture is correlated with the severe environmental conditions associated with increasing elevation, such as strong winds. In contrast to obvious variations in tree architecture, the genetic diversity of populations along the trails was almost uniform (H (E) = 0.717-0.762) across the altitudinal range. The results of the AMOVA and STRUCTURE analyses, and the analysis for isolation by distance pattern, suggest homogeneous genetic structuring across all populations on Mt. Fuji, while the pairwise F (ST) showed barriers to gene flow between altitudinal populations that were demarcated as high- or low-altitude populations by Abies-Tsuga forest. Although the evergreen coniferous forests on the mountainside may hinder gene flow, this may be explained by the long-distance seed dispersal of the Japanese larch and/or a short population history resulting from eruptions or slush avalanches, although evergreen coniferous forests on the mountainside may hinder gene flow.

  17. Transcriptome Analysis of mRNA and miRNA in Somatic Embryos of Larix leptolepis Subjected to Hydrogen Treatment

    PubMed Central

    Liu, Yali; Han, Suying; Ding, Xiangming; Li, Xinmin; Zhang, Lifeng; Li, Wanfeng; Xu, Haiyan; Li, Zhexin; Qi, Liwang

    2016-01-01

    Hydrogen is a therapeutic antioxidant that has been used extensively in clinical trials. It also acts as a bioactive molecule that can alleviate abiotic stress in plants. However, the biological effects of hydrogen in somatic embryos and the underlying molecular basis remain largely unknown. In this study, the morphological and physiological influence of exogenous H2 treatment during somatic embryogenesis was characterized in Larix leptolepis Gordon. The results showed that exposure to hydrogen increased the proportions of active pro-embryogenic cells and normal somatic embryos. We sequenced mRNA and microRNA (miRNA) libraries to identify global transcriptome changes at different time points during H2 treatment of larch pro-embryogenic masses (PEMs). A total of 45,393 mRNAs and 315 miRNAs were obtained. Among them, 4253 genes and 96 miRNAs were differentially expressed in the hydrogen-treated libraries compared with the control. Further, a large number of the differentially expressed mRNAs and miRNAs were related to reactive oxygen species (ROS) homeostasis and cell cycle regulation. We also identified 4399 potential target genes for 285 of the miRNAs. The differential expression data and the mRNA-miRNA interaction network described here provide new insights into the molecular mechanisms that determine the performance of PEMs exposed to H2 during somatic embryogenesis. PMID:27879674

  18. Transcriptome Analysis of mRNA and miRNA in Somatic Embryos of Larix leptolepis Subjected to Hydrogen Treatment.

    PubMed

    Liu, Yali; Han, Suying; Ding, Xiangming; Li, Xinmin; Zhang, Lifeng; Li, Wanfeng; Xu, Haiyan; Li, Zhexin; Qi, Liwang

    2016-11-22

    Hydrogen is a therapeutic antioxidant that has been used extensively in clinical trials. It also acts as a bioactive molecule that can alleviate abiotic stress in plants. However, the biological effects of hydrogen in somatic embryos and the underlying molecular basis remain largely unknown. In this study, the morphological and physiological influence of exogenous H₂ treatment during somatic embryogenesis was characterized in Larix leptolepis Gordon. The results showed that exposure to hydrogen increased the proportions of active pro-embryogenic cells and normal somatic embryos. We sequenced mRNA and microRNA (miRNA) libraries to identify global transcriptome changes at different time points during H₂ treatment of larch pro-embryogenic masses (PEMs). A total of 45,393 mRNAs and 315 miRNAs were obtained. Among them, 4253 genes and 96 miRNAs were differentially expressed in the hydrogen-treated libraries compared with the control. Further, a large number of the differentially expressed mRNAs and miRNAs were related to reactive oxygen species (ROS) homeostasis and cell cycle regulation. We also identified 4399 potential target genes for 285 of the miRNAs. The differential expression data and the mRNA-miRNA interaction network described here provide new insights into the molecular mechanisms that determine the performance of PEMs exposed to H₂ during somatic embryogenesis.

  19. Unification of Larch and Z-Based Object Models to Support Algebraically-Based Design Refinement: The Larch Perspective.

    DTIC Science & Technology

    1994-12-01

    t’NIFI(ATION OF LARCH AND 7-13ASED OBJECT MODELS TO SUIPPORT ALGEBR \\I(’.LLY-IIASEI) DESIGN [EFINE •I E’NT: TIlE LARCH I[ERSPECTIVE FIIFSIS...Container(Int, C) includes Integer, PairwiseExtension(+, E, Int, C) implies (AssociativeC(E, C), Commutative (CE for o, C for T, C for Range)) 0.2 Graph

  20. Warm season precipitation signal in δ(2) H values of wood lignin methoxyl groups from high elevation larch trees in Switzerland.

    PubMed

    Riechelmann, Dana F C; Greule, Markus; Siegwolf, Rolf T W; Anhäuser, Tobias; Esper, Jan; Keppler, Frank

    2017-10-15

    In this study, we tested stable hydrogen isotope ratios of wood lignin methoxyl groups (δ(2) Hmethoxyl values) as a palaeoclimate proxy in dendrochronology. This is a quite new method in the field of dendrochronology and the sample preparation is much simpler than the methods used before to measure δ(2) H values from wood. We measured δ(2) Hmethoxyl values in high elevation larch trees (Larix decidua Mill.) from Simplon Valley (southern Switzerland). Thirty-seven larch trees were sampled and five individuals analysed for their δ(2) Hmethoxyl values at annual (1971-2009) and pentadal resolution (1746-2009). The δ(2) Hmethoxyl values were measured as CH3 I released upon treatment of the dried wood samples with hydroiodic acid. 10-90 μL from the head-space were injected into the gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/HTC-IRMS) system. Testing the climate response of the δ(2) Hmethoxyl values, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation. The pentadally resolved δ(2) Hmethoxyl series do not show any significant correlation to climate parameters. Increased precipitation during June and July, which are on average warm and relatively dry months, results in higher δ(2) H values of the xylem water and, therefore, higher δ(2) H values in the lignin methoxyl groups. Therefore, we suggest that δ(2) Hmethoxyl values of high elevation larch trees might serve as a summer precipitation proxy. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Long-term Impacts of Fire on Permafrost Vulnerability and C loss in Siberian Larch Forests

    NASA Astrophysics Data System (ADS)

    Egan, J. E.; Natali, S.; Alexander, H. D.; Loranty, M. M.; Spawn, S.; Risk, D. A.

    2015-12-01

    In Boreal forests, which contain large stocks of terrestrial carbon (C), fires have been increasing and are expected to continue to do so as the climate becomes warmer and dryer. Here we studied the indirect, long-term effects of fire on ecosystem C cycling via changes in stand density, organic layer and thaw depth in, in Siberian larch (Larix cajanderi) forests, underlain by continuous permafrost, near Chersky, Russia. Understory net ecosystem exchange (NEE), ecosystem respiration (Reco) and thaw depth were measured for 3 growing seasons from density plots (related to fire severity) found within a 75-yr burn scar and from experimental burn plots. In 2015, Reco was partitioned, using a dual-isotope approach, to determine how fire severity alters the contribution of autotrophic and heterotrophic respiration. Reco gas samples were collected from static chambers, and at the density gradient we also collected carbon dioxide (CO2) from Reco sources (organic and mineral layer soils, above and belowground vegetation). We expect that differences in thaw depth, vegetation and organic layer related to stand density, will impact the contribution of old C sources to Reco. In the experimental burn plots, the severity of the burn and thaw depth were positively correlated, and promoted loss of old C. Following the fires in 2012, higher intensity burns decreased Reco, but 3 years later, Reco was similar across burn treatments. In the 75-yr burn, stand density significantly impacted both thaw depth and understory CO2 exchange, where higher density stands, had lower thaw depths, higher understory NEE, and C loss from young C sources that have assimilated since the fire. Decades after fire, permafrost vulnerability and C accumulation are driven by stand density, where higher-density stands have higher rates of NEE, but C loss from relatively young C.

  2. The relationship between needle sugar carbon isotope ratios and tree rings of larch in Siberia.

    PubMed

    Rinne, K T; Saurer, M; Kirdyanov, A V; Loader, N J; Bryukhanova, M V; Werner, R A; Siegwolf, R T W

    2015-11-01

    Significant gaps still exist in our knowledge about post-photosynthetic leaf level and downstream metabolic processes and isotopic fractionations. This includes their impact on the isotopic climate signal stored in the carbon isotope composition (δ(13)C) of leaf assimilates and tree rings. For the first time, we compared the seasonal δ(13)C variability of leaf sucrose with intra-annual, high-resolution δ(13)C signature of tree rings from larch (Larix gmelinii Rupr.). The trees were growing at two sites in the continuous permafrost zone of Siberia with different growth conditions. Our results indicate very similar low-frequency intra-seasonal trends of the sucrose and tree ring δ(13)C records with little or no indication for the use of 'old' photosynthates formed during the previous year(s). The comparison of leaf sucrose δ(13)C values with that in other leaf sugars and in tree rings elucidates the cause for the reported (13)C-enrichment of sink organs compared with leaves. We observed that while the average δ(13)C of all needle sugars was 1.2‰ more negative than δ(13)C value of wood, the δ(13)C value of the transport sugar sucrose was on an average 1.0‰ more positive than that of wood. Our study shows a high potential of the combined use of compound-specific isotope analysis of sugars (leaf and phloem) with intra-annual tree ring δ(13)C measurements for deepening our understanding about the mechanisms controlling the isotope variability in tree rings under different environmental conditions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Early and late seasonal carbon sequestration and allocation in larch trees growing on permafrost in Central Siberia

    NASA Astrophysics Data System (ADS)

    Masyagina, Oxana; Prokushkin, Anatoly; Kirdyanov, Alexander; Artyukhov, Aleksey; Udalova, Tatiana; Senchenkov, Sergey; Rublev, Aleksey

    2014-05-01

    Despite large geographic extent of deciduous conifer species Larix gmelinii, its seasonal photosynthetic activity and translocation of photoassimilated carbon within a tree remain poorly studied. To get better insight into productivity of larch trees growing on permafrost soils in Siberian larch biome we aimed to analyze dynamics of foliage parameters (i.e. leaf area, biomass, %N, %P etc.), seasonal dynamics of photosynthetic activity and apply whole tree labeling by 13CO2, which is powerful and effective tool for tracing newly developed assimilates translocation to tissues and organs of a tree (Kagawa et al., 2006; Keel et al., 2012). Experimental plot has been established in mature 105 year-old larch stand located within the continuous permafrost area near Tura settlement (Central Siberia, 64o17'13" N, 100o11'55" E, 148 m a.s.l.). Trees selected for experiments represented mean tree of the stand. Measurements of seasonal photosynthetic activity and foliar biomass sampling were arranged from early growing season (June 8, 2013) until yellowing and senescence of needles on September 17, 2013. Labeling by 13C in whole tree chamber was conducted by three pulses ([CO2]max ≤ 2,500 ppmv, 13CO2 (30% v/v)) at the early (June) and late (August) phase of growing season for different trees in 3 replicates each time. Both early season and late season labeling experiments demonstrated high rate of 13CO2 assimilation and respective enrichment of needle tissues by 13C: δ13C increased from -28.7 up to +670‰ just after labeling. However, there was distinct post-labeling dynamics of needle δ13C among two seasonal experiments. At the early season 13C depletion in labeled needles was slower, and δ13C approached after 40 days ca. +110 ‰ and remained constant till senescence. In the late season (August) needles were losing labeled C with much faster rate and approached only +1.5 ‰ upon senescence (28 days exposition). These findings suggest that in early season ca. 20% of

  4. Climatic interpretation of tree-ring methoxyl d2H time-series from a central alpine larch forest

    NASA Astrophysics Data System (ADS)

    Riechelmann, Dana F. C.; Greule, Markus; Siegwolf, Rolf T. W.; Esper, Jan; Keppler, Frank

    2017-04-01

    We measured stable hydrogen isotope ratios of lignin methoxyl groups (d2HLM) in high elevation larch trees (Larix decidua Mill.) from the Simplon Valley in southern Switzerland. Thirty-seven larch trees were sampled and five individuals analysed for their d2HLM values at annual (1971-2009) and pentadal resolution (1746-2009). Testing the climate response of the d2HLM series, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation and weaker but negative correlation with June/July temperature. In addition, a negative correlation with June-August d2H in precipitation of the nearby GNIP station in Locarno is observed. The pentadally resolved d2HLM series show no significant correlation to climate parameters. The positive correlation of the annually resolved data to summer precipitation is uncommon to d2H measurements from tree-rings (Feakins et al., 2013; Helle and Schleser, 2004; McCarroll and Loader, 2004; Mischel et al., 2015; White et al., 1994). However, we explain the positive association with warm season hydroclimate as follows: methoxyl groups of lignin are directly formed from tissues in the xylem water. More precipitation during June and July, which are on average relatively dry month, results in higher d2H values of the xylem water and therefore, higher d2H value in the lignin methoxyl groups. Therefore, we suggest that d2HLM values of high elevation larch trees might likely serve as a summer precipitation proxy. References: Feakins, S.J., Ellsworth, P.V., Sternberg, L.d.S.L., 2013. Lignin methoxyl hydrogen isotope rations in a coastal ecosystem. Geochimica et Cosmochimica Acta, 121: 54-66. Helle, G., Schleser, G.H., 2004. Interpreting Climate Proxies from Tree-rings. In: Fischer, H., Floeser, G., Kumke, T., Lohmann, G., Miller, H., Negendank, J.F.W., et al., editors. The Climate in Historical Times. Springer Berlin Heidelberg, pp. 129-148. McCarroll, D., Loader, N.J., 2004. Stable isotopes in tree rings. Quaternary

  5. Climate signal in d13C of wood lignin methoxyl groups from high-elevation alpine larch trees

    NASA Astrophysics Data System (ADS)

    Reichelmann, Dana; Greule, Markus; Treydte, Kerstin; Keppler, Frank; Esper, Jan

    2015-04-01

    Tree-rings of high alpine larch trees (Larix decidua) were investigated by a recently established method that measures d13C values of the wood lignin methoxyl groups (Greule et al. 2009). The resulting d13C time series were tested for their potential as a climate proxy. For this 37 larch trees were sampled at the tree line near Simplon Village (Southern Switzerland). They were analysed for their tree-ring width (TRW) and from five individuals d13C of the wood lignin methoxyl groups (d13Cmethoxyl) were measured at annual resolution from 1971-2009 and at pentadal resolution from 1747-2009. The d13Cmethoxyl chronologies were corrected for the anthropogenic change in atmospheric CO2 concentration and its decreasing d13C value. Further, the physiological response of the trees to these atmospheric changes was corrected using the flexible correction factor approach of Treydte et al. (2009), which minimise the residuals with the target climate data. This approach results in the highest so far reported correction factors of 0.032 - 0.036‰/ppmv CO2, which are explained by a low water-use efficiency of deciduous larch. The climate response of the new d13Cmethoxyl proxy shows a significant correlation of 0.75 for the annually and 0.87 for the pentadally resolved data with June to August temperatures. TRW shows also significant correlations with June to August temperatures, but they are lower than the correlations observed for the d13Cmethoxyl chronologies. These results indicate the potential of d13Cmethoxyl chronologies as a summer temperature proxy from high-elevation alpine trees with an even stronger signal than reported from earlier published tree-ring width and maximum latewood density temperature reconstructions. References: Greule, M., Mosandl, A., Hamilton, J.T.G., Keppler, F., 2009. A simple rapid method to precisely determine 13C/12C ratios of plant methoxyl groups. Rapid Communications in Mass Spectrometry, 23(11): 1710-1714. Treydte, K.S., Frank, D.C., Saurer, M

  6. Effects of fertilization on the growth and development of a Japanese larch plantation in West Virginia

    Treesearch

    James N. Kochenderfer; H. Clay Smith; Jerry T. Crews

    1995-01-01

    The effects of fertilization on the growth and development of a Japanese larch plantation in central West Virginia were evaluated after 9 years. Mean height and diameter growth of the larch trees were greater on the unfertilized plots. Foliar and soil chemical analyses were used to examine this apparent anomaly. Japanese larch demonstrated an ability to grow well on a...

  7. An Intercomparison of Stable Isotopes in Tree-Ring Earlywood and Latewood from Two European Tree Line Sites

    NASA Astrophysics Data System (ADS)

    Kress, A.; Young, G. H. F.; Saurer, M.; Loader, N.; Siegwolf, R.; McCarroll, D.

    2009-04-01

    Annually resolved and replicated stable isotope series obtained from tree-rings have the potential to reconstruct climate parameters, such as temperature, at multi-millennial timescales, at all temporal frequencies as they appear to require no statistical detrending. Over such timescales, sample numbers are large and preparation is costly and time consuming. To date, many studies have utilised only latewood rather than using the entire tree-ring to maximise the annual resolution and to avoid carry-over effects from reserves. However, the old trees from tree-line locations that are required to build long chronologies often display narrow ring-widths (< 0.5 mm), making accurate earlywood-latewood separation difficult, often inaccurate and time consuming. In this study tree-ring stable isotopes from two European tree-line locations were analysed to test the homogeneity of signal between latewood, earlywood and whole-ring cellulose. Scots pine (Pinus sylvestris) from Northern Norway and European larch (Larix decidua Mill.) from Southern Switzerland were chosen as tree-ring stable isotopes at both these sites are strongly linked to temperature. As a part of the EU funded Millennium project, which seeks to investigate European climate variability over the last 1,000 years, it is essential to clarify if the separation of earlywood and latewood is necessary to obtain reliable climate reconstructions. Our results demonstrate a high common signal between isotopes from earlywood and latewood in both species, correlating strongly with summer temperature. High turnover rates and small reserve pools at these tree-line locations may account for such a high common signal between earlywood and latewood. These results suggest that, for European tree-line conifers, the separation of earlywood from latewood is unnecessary to resolve an annual isotopic signal and to make accurate climate calibrations. Indeed, using the whole-ring may even improve climate correlations and therefore

  8. Examining the response of larch needle carbohydrates to climate using compound-specific δ13C and concentration analyses

    NASA Astrophysics Data System (ADS)

    Rinne, Katja T.; Saurer, Matthias; Kirdyanov, Alexander V.; Bryukhanova, Marina V.; Prokushkin, Anatoly S.; Churakova Sidorova, Olga V.; Siegwolf, Rolf T. W.

    2016-04-01

    Little is known about the dynamics of concentrations and carbon isotope ratios of individual carbohydrates in leaves in response to climatic and physiological factors. Improved knowledge of the isotopic ratio in sugars will enhance our understanding of the tree ring isotope ratio and will help to decipher environmental conditions in retrospect more reliably. Carbohydrate samples from larch (Larix gmelinii) needles of two sites in the continuous permafrost zone of Siberia with differing growth conditions were analysed with the Compound-Specific Isotope Analysis (CSIA). We compared concentrations and carbon isotope values (δ13C) of sucrose, fructose, glucose and pinitol combined with phenological data. The results for the variability of the needle carbohydrates show high dynamics with distinct seasonal characteristics between and within the studied years with a clear link to the climatic conditions, particularly vapour pressure deficit. Compound-specific differences in δ13C values as a response to climate were detected. The δ13C of pinitol, which contributes up to 50% of total soluble carbohydrates, was almost invariant during the whole growing season. Our study provides the first in-depth characterization of compound-specific needle carbohydrate isotope variability, identifies involved mechanisms and shows the potential of such results for linking tree physiological responses to different climatic conditions.

  9. Maturation in larch: age-related changes in xylem development in the long-shoot foliage and the main stem.

    PubMed

    Takemoto, Y; Greenwood, M S

    1993-10-01

    As the meristems of eastern larch (Larix laricina (Du Roi) K. Koch) mature, they produce long-shoot foliage with progressively higher chlorophyll content and net photosynthesis and progressively lower specific leaf area (Hutchison et al. 1990). Despite the apparent increase in foliar vigor, both shoot height and diameter growth rates declined during maturation. These changes were associated with changes in xylem morphology of the vascular tissue of both the long-shoot foliage and the main stem. Although the number of xylem cells remained constant in a cross section of the foliage, their diameters increased with age. With increasing maturation, the same number of xylem cells were produced per radial file in the annual rings of the main stem, but their radial diameters decreased, which accounted for the decrease in diameter growth. There was no change in tracheid length during maturation. We conclude that the decrease in growth rate with increased maturation is not due to a decrease in physiological vigor of the foliage, but is a function of reduced sink strength of the growing shoots.

  10. Larch: X-ray Analysis for Synchrotron Applications using Python

    NASA Astrophysics Data System (ADS)

    Newville, Matthew

    2017-03-01

    Larch is an open-source library and toolkit written in Python for processing and analyzing X-ray spectroscopic data. The primary emphasis is on X-ray spectroscopic and scattering data collected at modern synchrotron sources. Larch provides a wide selection of general-purpose processing, analysis, and visualization tools for processing X-ray data; its related target application areas include X-ray absorption fine structure (XAFS), micro-X-ray fluorescence (XRF) maps, quantitative X-ray fluorescence, X-ray absorption near edge spectroscopy (XANES), and X-ray standing waves and surface scattering. Larch provides a complete set of XAFS Analysis tools and has support for visualizing and analyzing XRF maps and spectra, and additional tools for X-ray spectral analysis, data handling, and general-purpose data modeling.

  11. Antennal responses of the two host races of the larch bud moth, Zeiraphera diniana, to larch and cembran pine volatiles.

    PubMed

    Syed, Z; Guerin, P M; Baltensweiler, W

    2003-07-01

    The larch bud moth (LBM) Zeiraphera diniana Guenée causes defoliation on larch in the Alps at 8- to 10-year intervals, after which populations crash. There are two LBM host races, one on larch and the other on cembran pine. These host races are morphologically indistinguishable as adults but they differ genetically in larval color types. Furthermore, females of each host race produce distinct pheromone blends and show oviposition preferences for their respective hosts. It is not clear to what extent host choice contributes to assortative mating in the LBM. Here, we compare the olfactory sensitivities of the two host races to the odors of fresh foliage of the host plants using the electroantennogram (EAG) technique, and the responses of the two host races to volatiles collected from the two host plants as analyzed by gas-chromatography-linked antennographic detection (GC-EAD). Both sexes of the larch and cembran host races show the same EAG responses to vapors of fresh larch and cembran pine foliage. Fifteen plant volatiles identified as chemostimuli by GC-EAD from larch and cembran pine odors elicited the same antennogram responses from the two host races. However, the GC-EAD analyses indicate that the number and quantity of chemostimuli emanating from each host plant is different. It is, therefore, most probably the array of olfactory receptors responding to the bouquet of volatiles unique to each host plant that underlies the host preferences of the two races. What remains open is the extent to which the similarity of the olfactory systems may contribute to cross-attraction. The fact that LBM individuals with intermediate characteristics between the two host races exist, suggests that olfactory perception does not hinder gene flow and contributes to sustained genetic diversity within the species Z. diniana.

  12. Effect of nitrogen fertilizer, root branch order and temperature on respiration and tissue N concentration of fine roots in Larix gmelinii and Fraxinus mandshurica.

    PubMed

    Jia, Shuxia; Wang, Zhengquan; Li, Xingpeng; Zhang, Xiaoping; McLaughlin, Neil B

    2011-07-01

    Root respiration is closely related to root morphology, yet it is unclear precisely how to distinguish respiration-related root physiological functions within the branching fine root system. Root respiration and tissue N concentration were examined for different N fertilization treatments, sampling dates, branch orders and temperatures of larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) using the excised roots method. The results showed that N fertilization enhanced both root respiration and tissue N concentration for all five branch orders. The greatest increases in average root respiration for N fertilization treatment were 13.30% in larch and 18.25% in ash at 6°C. However, N fertilization did not change the seasonal dynamics of root respiration. Both root respiration and root tissue N concentration decreased with increase in root branch order. First-order (finest) roots exhibited the highest respiration rates and tissue N concentrations out of the five root branch orders examined. There was a highly significant linear relationship between fine root N concentration and root respiration rate. Root N concentration explained >60% of the variation in respiration rate at any given combination of root order and temperature. Root respiration showed a classical exponential relationship with temperature, with the Q(10) for root respiration in roots of different branching orders ranging from 1.62 to 2.20. The variation in root respiration by order illustrates that first-order roots are more metabolically active, suggesting that roots at different branch order positions have different physiological functions. The highly significant relationship between root respiration at different branch orders and root tissue N concentration suggests that root tissue N concentration may be used as a surrogate for root respiration, simplifying future research into the C dynamics of rooting systems.

  13. How does western spruce budworm feeding affect western larch?

    Treesearch

    David G. Fellin; Wyman C. Schmidt

    1973-01-01

    This pictorial describes how western spruce budworm larvae feed on young western larch and the trees' responses to this damage. Larvae feed not only on the current year's foliage-their usual diet on most coniferous hosts-but also sever stems of current year's shoots. Multiple-topped, bushlike trees develop in direct response to the amount and type of...

  14. Effects of larch defenses on xylophagous insect guilds

    Treesearch

    Galina I. Girs; Victor M. Yanovsky

    1991-01-01

    One of the best studies of a xylophage consortium is the case of larch insects by Isaev and Girs (1975). In their book, a basic theory was presented about host responses to xylophagous insects injury. According to their concept of "sliding resistance," different trunk-infesting insect species have different reactions to the tree's defenses and invade the...

  15. Emissions of biogenic volatile organic compounds and subsequent formation of secondary organic aerosols in a Larix kaempferi forest

    NASA Astrophysics Data System (ADS)

    Mochizuki, T.; Miyazaki, Y.; Ono, K.; Wada, R.; Takahashi, Y.; Saigusa, N.; Kawamura, K.; Tani, A.

    2015-04-01

    We conducted simultaneous measurements of concentrations and above-canopy fluxes of isoprene and α-pinene, along with their oxidation products in aerosols in a Larix kaempferi (Japanese larch) forest in summer 2012. Vertical profiles of isoprene showed the maximum concentration near the forest floor with a peak around noon, whereas oxidation products of isoprene, i.e., methacrolein (MACR) and methyl vinyl ketone (MVK), showed higher concentrations near the canopy level of the forest. The vertical profile suggests large emissions of isoprene near the forest floor, likely due to Dryopteris crassirhizoma (a fern species), and the subsequent reaction within the canopy. The concentrations of α-pinene also showed highest values near the forest floor with maximums in the early morning and late afternoon. The vertical profiles of α-pinene suggest its large emissions from soil and litter in addition to emissions from L. kaempferi leaves at the forest site. Isoprene and its oxidation products in aerosols exhibited similar diurnal variations within the forest canopy, providing evidence for secondary organic aerosol (SOA) formation via oxidation of isoprene most likely emitted from the forest floor. Although high abundance of α-pinene was observed in the morning, its oxidation products in aerosols showed peaks in daytime, due to a time lag between the emission and atmospheric reactions of α-pinene to form SOA. Positive matrix factorization (PMF) analysis indicated that anthropogenic influence is the most important factor contributing to the elevated concentrations of molecular oxidation products of isoprene- (> 64%) and α-pinene-derived SOA (> 57%). The combination of the measured fluxes and vertical profiles of biogenic volatile organic compounds (BVOCs) suggests that the inflow of anthropogenic precursors/aerosols likely enhanced the formation of both isoprene- and α-pinene-SOA within the forest canopy even when the BVOC flux was relatively low. This study highlights

  16. Tandem repeat DNA localizing on the proximal DAPI bands of chromosomes in Larix, Pinaceae.

    PubMed

    Hizume, Masahiro; Shibata, Fukashi; Matsumoto, Ayako; Maruyama, Yukie; Hayashi, Eiji; Kondo, Teiji; Kondo, Katsuhiko; Zhang, Shozo; Hong, Deyuan

    2002-08-01

    Repetitive DNA was cloned from HindIII-digested genomic DNA of Larix leptolepis. The repetitive DNA was about 170 bp long, had an AT content of 67%, and was organized tandemly in the genome. Using fluorescence in situ hybridization and subsequent DAPI banding, the repetitive DNA was localized in DAPI bands at the proximal region of one arm of chromosomes in L. leptolepis and Larix chinensis. Southern blot hybridization to genomic DNA of seven species and five varieties probed with cloned repetitive DNA showed that the repetitive DNA family was present in a tandem organization in genomes of all Larix taxa examined. In addition to the 170-bp sequence, a 220-bp sequence belonging to the same DNA family was also present in 10 taxa. The 220-bp repeat unit was a partial duplication of the 170-bp repeat unit. The 220-bp repeat unit was more abundant in L. chinensis and Larix potaninii var. macrocarpa than in other taxa. The repetitive DNA composed 2.0-3.4% of the genome in most taxa and 0.3 and 0.5% of the genome in L. chinensis and L. potaninii var. macrocarpa, respectively. The unique distribution of the 220-bp repeat unit in Larix indicates the close relationship of these two species. In the family Pinaceae, the LPD (Larix proximal DAPI band specific repeat sequence family) family sequence is widely distributed, but their amount is very small except in the genus Larix. The abundant LPD family in Larix will occur after its speciation.

  17. Trace element concentrations in needles and bark of Larix Sibirica within the Mo-W ore field (Buryat Republic, Russia)

    NASA Astrophysics Data System (ADS)

    Timofeev, Ivan; Kosheleva, Natalia

    2016-04-01

    The present study aims to assess the changes in the trace element (TE) composition of Larix Sibirica species growing in the impact area of Dzhida Mo-W plant in the Zakamensk city. The objectives of the study were: (1) to reveal the biogeochemical background features and changes in the TE composition of larch needles and bark in the mining region; (2) to determine patterns of spatial distribution of TE content in larch organs; (3) to assess the ecological state of larch plantation in different land-use zones of the city. A landscape-geochemical survey of the territory was carried out in summer of 2013. Total of 21 mixed (taken from 3-5 trees) samples of needles and bark were collected in undisturbed and different land-use areas. The bulk contents of TEs in dry plant samples were analyzed by mass spectrometry with induced coupled plasma. Sixteen priority pollutants were selected for thorough analysis, including elements of hazard classes I (Zn, As, Pb, Cd), II (Cr, Co, Ni, Cu, Mo, Sb), III (V, Sr, Ba, W), and some others (Sn, Bi). Concentrations of TEs (C_b) in background trees were compared with the global clarks (C_g) for annual increment of terrestrial vegetation (Dobrovol'skii 2003) via calculating the global enrichment EF_g=C_b/Cg and dispersion factors DF_g=C_g/C_b}. The concentrations of the elements in the urban samples Ci were grouped depending on the type of land use and compared with the background (C_b) via calculating the local enrichment EF_l=C_i/Cb and dispersion factors DF_l=C_b/C_i. The ecological state of the urban plants was diagnosed using three TE ratios. The Fe/Mn ratio represents photosynthetic activity with optimum value 1.5-2.5. The Pb/Mn ratio characterizes balance between technogenic and biophilic elements, its value for unpolluted terrestrial plants is 0.006. The Cu/Zn ratio determines the proportionality in the provision of enzyme synthesis with these metals, its optimum value is 0.27. TE composition of needles of background larch is

  18. Effect of warming on larch trees in the Asian southern border of the boreal forest, Mongolia and China in the 20th century.

    NASA Astrophysics Data System (ADS)

    Lopez Caceres, Maximo Larry; Cho, Qiqin; Nobori, Yoshihiro; Takeda, Kazuo; Byambasuren, Mijidsuren; Zhang, Yandong; Sugimoto, Atsuko

    2016-04-01

    In recent decades air temperature (Ta) has been increasing steadily around the globe and it is reported that in the last 40 years Ta in Mongolia alone has increased by about 2.1 deg.C. The boreal region as a whole is expected to experience changes due to atmospheric drying, permafrost degradation, increases in the frequency of forest fires and other factors that will lead to a shift of the forest ecosystems northward. The southern border of the boreal forest distributes in northern Mongolia and northeast China, which as transition areas are more sensitive to changes. In a 500 km long south-north transect of larch forests extending in each of these two countries, larch forest sites were chosen (Larix sibirica in Mongolia and Larix gmeliini in China). Studies until now have used only tree-ring analysis to determined past and recent climate in Mongolia and China. However, isotope analysis has not been coupled with this analysis to give a wider overview of the environmental changes taking place in these regions. Therefore in this study tree core samples were collected for tree-ring and carbon isotope analysis to be coupled with available meteorological data. These data indicate that in the last four decades, the northernmost site of the selected transect has experienced the largest increase in Ta, but nevertheless the annual Ta in the southernmost site remained several degrees higher. On the other hand precipitation shows a very slight increase in the central and northernmost sites while an insignificant decrease is observed in the southernmost site. Tree-ring analysis shows that for most of the 20th century tree ring growth had lower inter-annual variability until the beginning of the 1970's but from then on the annual variability has increased. Unlike the results of the tree-ring analysis, the carbon isotope analysis revealed that until the 1970's the increases in the drying atmospheric conditions (higher temperature-no changes in rainfall) were not present but the

  19. Intraseasonal carbon sequestration and allocation in larch trees growing on permafrost in Siberia after (13)C labeling (two seasons of 2013-2014 observation).

    PubMed

    Masyagina, Oxana; Prokushkin, Anatoly; Kirdyanov, Alexander; Artyukhov, Aleksey; Udalova, Tatiana; Senchenkov, Sergey; Rublev, Aleksey

    2016-12-01

    This research is an attempt to study seasonal translocation patterns of photoassimilated carbon within trees of one of the high latitudes widespread deciduous conifer species Larix gmelinii (Rupr. Rupr). For this purpose, we applied whole-tree labeling by (13)CO2, which is a powerful and effective tool for tracing newly developed assimilates translocation to tissues and organs of a tree. Experimental plot has been established in a mature 105-year-old larch stand located within the continuous permafrost area near Tura settlement (Central Siberia, 64°17'13″N, 100°11'55″E, 148 m a.s.l.). Measurements of seasonal photosynthetic activity and foliage parameters (i.e., leaf length, area, biomass, etc.), and sampling were arranged from early growing season (June 8, 2013; May 14, 2014) until yellowing and senescence of needles (September 17, 2013; September 14, 2014). Labeling by (13)C of the tree branch (June 2013, for 3 branch replicates in 3 different trees) and the whole tree was conducted at early (June 2014), middle (July 2014), and late (August 2013) phase of growing season (for different trees in 3 replicates each time) by three pulses [(CO2)max = 3000-4000 ppmv, (13)CO2 (30 % v/v)]. We found at least two different patterns of carbon translocation associated with larch CO2 assimilation depending on needle phenology. In early period of growing season (June), (13)C appearing in newly developed needles is a result of remobilized storage material use for growth purposes. Then approximately at the end of June, growth processes is switching to storage processes lasting to the end of growing season.

  20. q-deformations and the dynamics of the larch bud-moth population cycles

    NASA Astrophysics Data System (ADS)

    Iyengar, Sudharsana V.; Balakrishnan, J.

    2014-07-01

    The concept of q-deformation of numbers is applied here to improve and modify a tritrophic population dynamics model to understand defoliation of the coniferous larch trees due to outbreaks of the larch bud-moth insect population. The results are in qualitative agreement with observed behavior, with the larch needle lengths, bud-moth population and parasitoid populations all showing 9-period cycles which are mutually synchronized.

  1. Year-round measurements of net ecosystem CO2 flux over a montane larch forest in Mongolia

    NASA Astrophysics Data System (ADS)

    Li, Sheng-Gong; Asanuma, Jun; Kotani, Ayumi; Eugster, Werner; Davaa, Gombo; Oyunbaatar, Dambaravjaa; Sugita, Michiaki

    2005-05-01

    Mongolian boreal forest merits special attention since it is located in the transitional area between the southern Siberian boreal forest and the Asian steppe zone, a vulnerable region being potentially affected by global warming and anthropogenic activities. This paper presents the first full-year-long continuous measurements of net ecosystem CO2 flux (NEE) made over a montane larch (Larix sibirica Ledeb.) forest in Mongolia from 25 March 2003 to 24 March 2004 (366 days) using the eddy covariance technique. The hourly maximum uptake was -10.1 μmol m-2 s-1. The maximum daily uptake of -4.0 g C m-2 d-1 (negative NEE values denote net carbon uptake by the canopy from the atmosphere) occurred in July. The annual cumulative NEE was -85 g C m-2, indicating that the forest acted as a net sink of CO2. We examined the responses of NEE to environmental conditions in the growing season from May to September. Both daytime 30-min mean and daily integrated NEE responded to incident photosynthetically active radiation (PAR) in a rectangular hyperbolic fashion. Model results show that the apparent quantum yield (α) was -0.0133 ± 0.0011 μmol CO2 per μmol of photons, and the bulk light use efficiency (LUE) on the daily basis was -6.7 mmol CO2 per mole of PAR photons over the entire growing season for this forest. Additionally, daily integrated NEE was also a linear function of the normalized difference vegetation index (NDVI), a linear function of mean daily air temperature (Ta), and a quadratic polynomial function of daily means of the atmospheric water vapor pressure deficit (VPD). Among these factors, LAI (as measured by NDVI) was dominant in affecting the dynamics of NEE, followed by Ta. Lower Ta was limiting the growth rate of this montane larch forest. As daily means of VPD exceeded 1.2 kPa, net CO2 uptake by the canopy declined. Nevertheless, water stress was not observed as a problem for the forest growth.

  2. Implications of fire-mediated changes in larch forest structure on leaf litter inputs, organic layer accumulation, and permafrost dynamics

    NASA Astrophysics Data System (ADS)

    Ganzlin, P.; Alexander, H. D.; Petronio, B.; Natali, S.; Davydov, S.

    2012-12-01

    The boreal forest is an expansive biome and stores the majority of the world's above and belowground carbon stocks. These forests are very vulnerable to changes in global climate. As climate warms and dries, boreal forest ecosystems are expected to experience greater fire activity. An increase in fire activity will likely lead to greater consumption of the soil organic layer (SOL), the thick layer of undecomposed mosses and other plant materials lying above the mineral soil. Because the SOL serves as a natural barrier to seed germination, a reduction in SOL depth could increase tree seedling establishment during post-fire succession. This could ultimately lead to stands of greater density, with potentially cascading effects on belowground carbon dynamics due to density-driven changes in understory microenvironment and leaf litter inputs, especially in forests dominated by deciduous species. In permafrost-affected regions, organic soil materials - especially mosses - are important insulators of permafrost and the high content of thermally protected carbon it contains. In order to assess the importance of fire-mediated changes in stand density on permafrost dynamics, we surveyed forests of Cajander Larch (Larix cajander) surrounding the Northeast Science Station in far northeastern Siberia. Two sets of low and high-density stands were selected to establish a natural density gradient in these forests. In each stand we evaluated stand density effects on aboveground biomass, leaf litter inputs, moss abundance, organic layer depth, and permafrost thaw depth. Here we show that the low-density larch stands had significantly higher moss abundance, green moss depth, and organic layer depth. The insulating organic layer was nearly 25% shallower in high-density stands, which was accompanied by a nearly 50% increase in depth of seasonal permafrost thaw. In addition to density, stand biomass and landscape position may also be very important factors in determining litter inputs

  3. Site-specific water-use strategies of mountain pine and larch to cope with recent climate change.

    PubMed

    Churakova Sidorova, Olga V; Saurer, Matthias; Bryukhanova, Marina V; Siegwolf, Rolf T W; Bigler, Christof

    2016-08-01

    We aim to achieve a mechanistic understanding of the eco-physiological processes in Larix decidua and Pinus mugo var. uncinata growing on north- and south-facing aspects in the Swiss National Park in order to distinguish the short- and long-term effects of a changing climate. To strengthen the interpretation of the δ(18)O signal in tree rings and its coherence with the main factors and processes driving evaporative δ(18)O needle water enrichment, we analyzed the δ(18)O in needle, xylem and soil water over the growing season in 2013 and applied the mechanistic Craig-Gordon model (1965) for the short-term responses. We found that δ(18)O needle water strongly reflected the variability of relative humidity mainly for larch, while only δ(18)O in pine xylem water showed a strong link to δ(18)O in precipitation. Larger differences in offsets between modeled and measured δ(18)O needle water for both species from the south-facing aspects were detected, which could be explained by the high transpiration rates. Different soil water and needle water responses for the two species indicate different water-use strategies, further modulated by the site conditions. To reveal the long-term physiological response of the studied trees to recent and past climate changes, we analyzed δ(13)C and δ(18)O in wood chronologies from 1900 to 2013. Summer temperatures as well as summer and annual amount of precipitations are important factors for growth of both studied species from both aspects. However, mountain pine trees reduced sensitivity to temperature changes, while precipitation changes come to play an important role for the period from 1980 to 2013. Intrinsic water-use efficiency (WUEi) calculated for larch trees since the 1990s reached a saturation point at elevated CO2 Divergent trends between pine WUEi and δ(18)O are most likely indicative of a decline of mountain pine trees and are also reflected in decoupling mechanisms in the isotope signals between needles and tree

  4. Nitrogen cycle inferred by δ15N in larch stand in northern Mongolia

    NASA Astrophysics Data System (ADS)

    Hayashi, Mika; Lopez C., Maximo Larry; Nobori, Yoshihiro; Byambasuren, Mijidsuren; Boy, Jens

    2017-04-01

    Mongolia represents the southernmost border of boreal forests and therefore is more sensitive to climate change. In boreal regions forest grow under N-limited conditions and for this reason rely on ectomycorrhizal fungi for the uptake of inorganic and dissolved organic N from the soil solution. A drastic increase in air temperature and a decrease or almost no change in summer precipitation has led to a severe climate induced drought that is expected to impact the nitrogen cycle in this region. Until now there has been no study on the nitrogen dynamics and especially not by means of stable isotope in the entire Eurasian boreal forests. Thus, in this study we evaluate the effect of spatial and climatic characteristics on the soil-tree N exchange in three representative larch forest stands (Larix sibirica) in the forest-steppe zone of central Mongolia. The results showed significant differences in the soil available N content and the influence that this difference exerts on the level of N fractionation from roots to leaves. In this study we observed heavier d15N in fine roots than in short roots (where the ectomycorrhizal fungi is attached) which was used as a proxy for soil available d15N. This value did not match total N d15N in any of the three sites selected for this study even though total N d15N has been used in previous studies as a proxy for available N d15N. Higher fractionation was observed in forest stands where available N was more limited indicating a heavier reliance on ectomycorrhizal fungi for inorganic N uptake. Coincidentally, the site with less available N was the southern site with the lowest precipitation. The opposite was found in the northern sites where available N was higher and thus fractionation showed lower values. Different tree tissues (fine and short-roots, stem, leaves) and litter showed multiple, intra-plant processes that influenced the isotope signal of the source-sink nitrogen dynamics.

  5. The impact of an inverse climate-isotope relationship in soil water on the oxygen-isotope composition of Larix gmelinii in Siberia.

    PubMed

    Saurer, Matthias; Kirdyanov, Alexander V; Prokushkin, Anatoly S; Rinne, Katja T; Siegwolf, Rolf T W

    2016-02-01

    Stable oxygen isotope ratios (δ(18) O) in trees from high latitude ecosystems are valuable sources of information for recent and past environmental changes, but the interpretation is hampered by the complex hydrology of forests growing under permafrost conditions, where only a shallow layer of soil thaws in summer. We investigated larch trees (Larix gmelinii) at two sites with contrasting soil conditions in Siberia and determined δ(18) O of water from different soil depths, roots, twigs, and needles as well as δ(18) O of soluble carbohydrates regularly over two growing seasons. A comparison of results from the 2 yrs revealed an unexpected 'inverse' climate-isotope relationship, as dry and warm summer conditions resulted in lower soil and root δ(18) O values. This was due to a stronger uptake of isotopically depleted water pools originating from melted permafrost or previous winter snow. We developed a conceptual framework that considers the dependence of soil water profiles on climatic conditions for explaining δ(18) O in needle water, needle soluble carbohydrates and stem cellulose. The negative feedback of drought conditions on the source isotope value could explain decreasing tree-ring δ(18) O trends in a warming climate and is likely relevant in many ecosystems, where a soil isotope gradient with depth is observed. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  6. Impact of climate change on larch budmoth cyclic outbreaks.

    PubMed

    Iyengar, Sudharsana V; Balakrishnan, Janaki; Kurths, Jürgen

    2016-06-13

    Periodic outbreaks of the larch budmoth Zeiraphera diniana population (and the massive forest defoliation they engender) have been recorded in the Alps over the centuries and are known for their remarkable regularity. But these have been conspicuously absent since 1981. On the other hand, budmoth outbreaks have been historically unknown in the larches of the Carpathian Tatra mountains. To resolve this puzzle, we propose here a model which includes the influence of climate and explains both the 8-9 year periodicity in the budmoth cycle and the variations from this, as well as the absence of cycles. We successfully capture the observed trend of relative frequencies of outbreaks, reproducing the dominant periodicities seen. We contend that the apparent collapse of the cycle in 1981 is due to changing climatic conditions following a tipping point and propose the recurrence of the cycle with a changed periodicity of 40 years - the next outbreak could occur in 2021. Our model also predicts longer cycles.

  7. Impact of climate change on larch budmoth cyclic outbreaks

    NASA Astrophysics Data System (ADS)

    Iyengar, Sudharsana V.; Balakrishnan, Janaki; Kurths, Jürgen

    2016-06-01

    Periodic outbreaks of the larch budmoth Zeiraphera diniana population (and the massive forest defoliation they engender) have been recorded in the Alps over the centuries and are known for their remarkable regularity. But these have been conspicuously absent since 1981. On the other hand, budmoth outbreaks have been historically unknown in the larches of the Carpathian Tatra mountains. To resolve this puzzle, we propose here a model which includes the influence of climate and explains both the 8–9 year periodicity in the budmoth cycle and the variations from this, as well as the absence of cycles. We successfully capture the observed trend of relative frequencies of outbreaks, reproducing the dominant periodicities seen. We contend that the apparent collapse of the cycle in 1981 is due to changing climatic conditions following a tipping point and propose the recurrence of the cycle with a changed periodicity of 40 years – the next outbreak could occur in 2021. Our model also predicts longer cycles.

  8. Testing aerially applied Orthene for control of larch casebearer.

    Treesearch

    John S. Hard; Stanley Meso; Michael Haskett

    1979-01-01

    Orthene was tested in a randomized block experiment to determine efficacy against larch casebearer. Needlemining larval populations were sprayed in September 1976 by helicopter with 0.5 lb Orthene/gal water/acre (560 g a.i/9.3 l/ha). Spray deposit was sampled with Kromekote cards. Plot mean larval populations, spray deposit, and defoliation index were analyzed to...

  9. Fourier transform infra-red spectroscopy using an attenuated total reflection probe to distinguish between Japanese larch, pine and citrus plants in healthy and diseased states

    NASA Astrophysics Data System (ADS)

    Gandolfo, D. S.; Mortimer, H.; Woodhall, J. W.; Boonham, N.

    2016-06-01

    FTIR spectroscopy coupled with an Attenuated Total Reflection (ATR) sampling probe has been demonstrated as a technique for detecting disease in plants. Spectral differences were detected in Japanese Larch (Larix kaempferi) infected with Phytophthora ramorum at 3403 cm-1 and 1730 cm-1, from pine (Pinus spp.) infected with Bursaphelenchus xylophilus at 1070 cm-1, 1425 cm-1, 1621 cm-1 and 3403 cm-1 and from citrus (Citrus spp.) infected with 'Candidatus liberibacter' at 960 cm-1, 1087 cm-1, 1109 cm-1, 1154 cm-1, 1225 cm-1, 1385 cm-1, 1462 cm-1, 1707 cm-1, 2882 cm-1, 2982 cm-1 and 3650 cm-1. A spectral marker in healthy citrus has been identified as Pentanone but is absent from the diseased sample spectra. This agrees with recent work by Aksenov, 2014. Additionally, the spectral signature of Cutin was identified in the spectra of Pinus spp. and Citrus spp. and is consistent with work by Dubis, 1999 and Heredia-Guerrero, 2014.

  10. Examining the response of needle carbohydrates from Siberian larch trees to climate using compound-specific δ(13) C and concentration analyses.

    PubMed

    Rinne, K T; Saurer, M; Kirdyanov, A V; Bryukhanova, M V; Prokushkin, A S; Churakova Sidorova, O V; Siegwolf, R T W

    2015-11-01

    Little is known about the dynamics of concentrations and carbon isotope ratios of individual carbohydrates in leaves in response to climatic and physiological factors. Improved knowledge of the isotopic ratio in sugars will enhance our understanding of the tree ring isotope ratio and will help to decipher environmental conditions in retrospect more reliably. Carbohydrate samples from larch (Larix gmelinii) needles of two sites in the continuous permafrost zone of Siberia with differing growth conditions were analysed with the Compound-Specific Isotope Analysis (CSIA). We compared concentrations and carbon isotope values (δ(13) C) of sucrose, fructose, glucose and pinitol combined with phenological data. The results for the variability of the needle carbohydrates show high dynamics with distinct seasonal characteristics between and within the studied years with a clear link to the climatic conditions, particularly vapour pressure deficit. Compound-specific differences in δ(13) C values as a response to climate were detected. The δ(13) C of pinitol, which contributes up to 50% of total soluble carbohydrates, was almost invariant during the whole growing season. Our study provides the first in-depth characterization of compound-specific needle carbohydrate isotope variability, identifies involved mechanisms and shows the potential of such results for linking tree physiological responses to different climatic conditions. © 2015 John Wiley & Sons Ltd.

  11. Transcriptomic Response to Nitric Oxide Treatment in Larix olgensis Henry

    PubMed Central

    Hu, Xiaoqing; Yang, Jingli; Li, Chenghao

    2015-01-01

    Larix olgensis Henry is an important coniferous species found in plantation forests in northeastern China, but it is vulnerable to pathogens. Nitric oxide (NO) is an important molecule involved in plant resistance to pathogens. To study the regulatory role of NO at the transcriptional level, we characterized the transcriptomic response of L. olgensis seedlings to sodium nitroprusside (SNP, NO donor) using Illumina sequencing and de novo transcriptome assembly. A significant number of putative metabolic pathways and functions associated with the unique sequences were identified. Genes related to plant pathogen infection (FLS2, WRKY33, MAPKKK, and PR1) were upregulated with SNP treatment. This report describes the potential contribution of NO to disease resistance in L. olgensis as induced by biotic stress. Our results provide a substantial contribution to the genomic and transcriptomic resources for L. olgensis, as well as expanding our understanding of the involvement of NO in defense responses at the transcriptional level. PMID:26633380

  12. Effect of nursery nitrogen application of bare-root Larix olgensis seedlings on growth, nitrogen uptake and initial field performance.

    PubMed

    Li, Guo Lei; Zhu, Yan; Liu, Yong; Jiang, Le; Shi, Wenhui; Liu, Jiajia; Wang, Jiaxi; Cheng, Zhongqian

    2013-01-01

    Nursery nitrogen application has been used to improve seedling quality. The technique has received little attention with bare-root seedlings and their subsequent field performance on weed competition sites. Our research objective was to examine responses of one- and two- year-old bare-root Olga Bay larch (Larix olgensis Henry) seedlings to nursery nitrogen supplements and subsequent one-year field performance on a competitive site. The fertilizer levels (kg N ha(-1)) were 0 (control), 60 (conventional fertilization, 60 C), 120 (additional nitrogen applied two times, 120 L), 180 (additional nitrogen applied three times, 180 L) and N were applied in increments of 30 kg ha(-1 )at 15-day interval to maintain a base nutrient level Although pre-planting morphological attributes and nitrogen status of one-year-old (la) seedlings were more sensitive to 60 C than for two-year-old (2a) seedlings, the conventional application failed to enhance their field survival (15.6% vs 17.8%), relative height growth (89.0% vs 79.6%), and relative diameter growth (17.0% vs 22.9%). The la seedlings' field survival (15.6% for 0, 17.8% for 60 C) and 2a seedlings' relative height growth rate (11.0% for 0, 8.9% for 60 C) were not increased significantly until they were provided the 120 L (survival of 23.3% for la, relative height growth rate of 15.0% for 2a). According to pre-planting attributes and field performance, optimum nursery nitrogen application was 120 L for the 2a seedlings and 180 L for la seedlings. Except for component nitrogen concentration, pre-planting morphological attributes and component N content for the 2a seedlings were as much 3.3 to 37.7 times that of la seedlings. In conclusion, the contrasting survival of poor (15.6%-28.9%) for la seedlings and high (84.4%-91.1%) for 2a seedlings indicated that additional nitrogen fertilizer would not equal the benefits of an another year's growth in the nursery. Successful reforestation could not be fulfilled by la seedlings

  13. Emissions of biogenic volatile organic compounds and subsequent formation of secondary organic aerosols in a Larix kaempferi forest

    NASA Astrophysics Data System (ADS)

    Mochizuki, T.; Miyazaki, Y.; Ono, K.; Wada, R.; Takahashi, Y.; Saigusa, N.; Kawamura, K.; Tani, A.

    2015-10-01

    We conducted simultaneous measurements of concentrations and above-canopy fluxes of isoprene and α-pinene, along with their oxidation products in aerosols in a Larix kaempferi (Japanese larch) forest in summer 2012. Vertical profiles of isoprene showed the maximum concentration near the forest floor with a peak around noon, whereas oxidation products of isoprene, i.e., methacrolein (MACR) and methyl vinyl ketone (MVK), showed higher concentrations near the canopy level of the forest. The vertical profile suggests large emissions of isoprene near the forest floor, likely due to Dryopteris crassirhizoma (a fern species), and the subsequent reaction within the canopy. The concentrations of α-pinene also showed highest values near the forest floor, with maximums in the early morning and late afternoon. The vertical profiles of α-pinene suggest its large emissions from soil and litter in addition to emissions from L. kaempferi leaves at the forest site. Isoprene and its oxidation products in aerosols exhibited similar diurnal variations within the forest canopy, providing evidence of secondary organic aerosol (SOA) formation via oxidation of isoprene most likely emitted from the forest floor. Although high abundance of α-pinene was observed in the morning, its oxidation products in aerosols showed peaks in daytime, due to a time lag between the emission and atmospheric reactions of α-pinene to form SOA. Positive matrix factorization (PMF) analysis indicated that anthropogenic influence is the most important factor contributing to the elevated concentrations of molecular oxidation products of isoprene- (> 64 %) and α-pinene-derived SOA (> 57 %). The combination of the measured fluxes and vertical profiles of biogenic volatile organic compounds (BVOCs) suggests that the inflow of anthropogenic precursors/aerosols likely enhanced the formation of both isoprene SOA and α-pinene SOA within the forest canopy even when the BVOC flux was relatively low. This study

  14. Impact of climate change on larch budmoth cyclic outbreaks

    PubMed Central

    Iyengar, Sudharsana V.; Balakrishnan, Janaki; Kurths, Jürgen

    2016-01-01

    Periodic outbreaks of the larch budmoth Zeiraphera diniana population (and the massive forest defoliation they engender) have been recorded in the Alps over the centuries and are known for their remarkable regularity. But these have been conspicuously absent since 1981. On the other hand, budmoth outbreaks have been historically unknown in the larches of the Carpathian Tatra mountains. To resolve this puzzle, we propose here a model which includes the influence of climate and explains both the 8–9 year periodicity in the budmoth cycle and the variations from this, as well as the absence of cycles. We successfully capture the observed trend of relative frequencies of outbreaks, reproducing the dominant periodicities seen. We contend that the apparent collapse of the cycle in 1981 is due to changing climatic conditions following a tipping point and propose the recurrence of the cycle with a changed periodicity of 40 years – the next outbreak could occur in 2021. Our model also predicts longer cycles. PMID:27293118

  15. mRNA accumulation in the Cajal bodies of the diplotene larch microsporocyte.

    PubMed

    Smoliński, Dariusz Jan; Kołowerzo, Agnieszka

    2012-02-01

    In microsporocytes of the European larch, we demonstrated the presence of several mRNAs in spherical nuclear bodies. In the nuclei of microsporocytes, we observed up to 12 bodies, ranging from 0.5 to 6 μm in diameter, during the prophase of the first meiotic division. Our previous studies revealed the presence of polyadenylated RNA (poly(A) RNA) in these bodies, but did not confirm the presence of nascent transcripts or splicing factors of the SR family. The lack of these molecules precludes the bodies from being the sites of synthesis and early maturation of primary transcripts (Kołowerzo et al., Protoplasma 236:13-19, 2009). However, the bodies serve as sites for the accumulation of splicing machinery, including the Sm proteins and small nuclear RNAs. Characteristic ultrastructures and the molecular composition of the nuclear bodies, which contain poly(A) RNA, are indicative of Cajal bodies (CBs). Here, we demonstrated the presence of several housekeeping gene transcripts--α-tubulin, pectin methylesterase, peroxidase and catalase, ATPase, and inositol-3-phosphate synthase--in CBs. Additionally, we observed transcripts of the RNA polymerase II subunits RPB2 and RPB10 RNA pol II and the core spliceosome proteins mRNA SmD1, SmD2, and SmE. The co-localization of nascent transcripts and mRNAs indicates that mRNA accumulation/storage, particularly in CBs, occurs in the nucleus of microsporocytes.

  16. Skyline logging productivity under alternative harvesting prescriptions and levels of utilization in larch-fir stands

    Treesearch

    Rulon B. Gardner

    1980-01-01

    Larch-fir stands in northwest Montana were experimentally logged to determine the influence of increasingly intensive levels of utilization upon rates of yarding production, under three different silvicultural prescriptions. Variables influencing rate of production were also identified.

  17. Recent (1977-1980) releases of imported larch casebearer parasites for biological control.

    Treesearch

    Roger B. Ryan

    1981-01-01

    Releases of Diadegma laricinellum (Hymenoptera: Ichneumonidae), Dicladocerus westwoodii, Dicladocerus japonicus, Chrysocharis laricinellae, Elachertus argissaj, Necremnus metalarus (Hymenoptera: Eulophidae), and Agathis pumila (Hymenoptera: Braconidae) for biological control of the larch casebearer in...

  18. Site index, height growth, normal yields and stocking levels for larch in Oregon and Washington.

    Treesearch

    P.H. Cochran

    1985-01-01

    Even-aged stands of larch in Oregon and Washington have cubic volume yields similar to yields from larch in Idaho and Montana. Site index values derived from the heights of the single tallest tree on 1/5-acre plots at an age at breast height of 50 years range from 50 to 110 feet. These values have the same index to productivity as the site index values of 30 to 90 feet...

  19. Wildfires Dynamics in Mid-Siberian Larch Dominated Communities

    NASA Technical Reports Server (NTRS)

    Kharuk, V. I.; Ranson. K. J.; Dvinskaya, M. L.

    2003-01-01

    The longterm wildfire dynamics, including fire return interval (FRI), in Siberian larch communities were examined. A wildfire chronology encompassing the 15th through the 20th centuries was developed from analyzing tree stem fire scars. Two methods were used to calculate the time interval between fires: 1) direct counting of annual tree growth rings between stem fire scars and 2) the next earlier fire date was estimated from growth ring analysis and added to the first estimate. Average FRI determined from stem fire scar dating was 82 plus or minus 7 using Method I or 95 plus or minus 7 when age of the next earlier fire was inferred from observed larch regeneration structure (Method II). FRI was also found to be dependent on site topography. FRI on north-east facing slopes was 86 plus or minus 11 years (105 plus or minus 12). FRI on south-west facing slopes was significantly less at 61 plus or minus 8 (73 plus ot minus 8) years. Flat terrain showed little difference between methods 68 plus or minus 14 (70 plus or minus 13). This was also the case for bogs, but FRI was much longer; 139 plus or minus 17 (138 plus ot minus 18). The maximum number of annual fires occurred with periods of 36 and 82 years on average. The temporal trend in the FRI decreased from 101 years in the 19 th century to 65 years in the 20th century. The effect of post-fire forest recovery on depth to permafrost was also estimated. After initial melting from increased local temperatures permafrost depth decreased at a rate of 0.3 cm/yr on average as forest canopies developed.

  20. Wildfires Dynamics in Mid-Siberian Larch Dominated Communities

    NASA Technical Reports Server (NTRS)

    Kharuk, V. I.; Ranson. K. J.; Dvinskaya, M. L.

    2003-01-01

    The longterm wildfire dynamics, including fire return interval (FRI), in Siberian larch communities were examined. A wildfire chronology encompassing the 15th through the 20th centuries was developed from analyzing tree stem fire scars. Two methods were used to calculate the time interval between fires: 1) direct counting of annual tree growth rings between stem fire scars and 2) the next earlier fire date was estimated from growth ring analysis and added to the first estimate. Average FRI determined from stem fire scar dating was 82 plus or minus 7 using Method I or 95 plus or minus 7 when age of the next earlier fire was inferred from observed larch regeneration structure (Method II). FRI was also found to be dependent on site topography. FRI on north-east facing slopes was 86 plus or minus 11 years (105 plus or minus 12). FRI on south-west facing slopes was significantly less at 61 plus or minus 8 (73 plus ot minus 8) years. Flat terrain showed little difference between methods 68 plus or minus 14 (70 plus or minus 13). This was also the case for bogs, but FRI was much longer; 139 plus or minus 17 (138 plus ot minus 18). The maximum number of annual fires occurred with periods of 36 and 82 years on average. The temporal trend in the FRI decreased from 101 years in the 19 th century to 65 years in the 20th century. The effect of post-fire forest recovery on depth to permafrost was also estimated. After initial melting from increased local temperatures permafrost depth decreased at a rate of 0.3 cm/yr on average as forest canopies developed.

  1. Dissimilar responses of larch stands in northern Siberia to increasing temperatures-a field and simulation based study.

    PubMed

    Wieczorek, Mareike; Kruse, Stefan; Epp, Laura S; Kolmogorov, Alexei; Nikolaev, Anatoly N; Heinrich, Ingo; Jeltsch, Florian; Pestryakova, Lyudmila A; Zibulski, Romy; Herzschuh, Ulrike

    2017-09-01

    Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. In our study, which was conducted in the Taimyr Depression in the North Siberian Lowlands, w present a combined field- and model-based approach helping us to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that tree density is highest in the forest-tundra, and average tree size decreases from closed forest to single-tree tundra. Age-structure analyses indicate that the trees in the closed forest and forest-tundra have been present for at least ~240 yr. At all sites except the most southerly ones, past establishment is positively correlated with regional temperature increase. In the single-tree tundra, however, a change in growth form from krummholz to erect trees, beginning ~130 yr ago, rather than establishment date has been recorded. Seed mass decreases from south to north, while seed quantity increases. Simulations with LAVESI (Larix Vegetation Simulator) further suggest that relative density changes strongly in response to a warming signal in the forest-tundra while intra-specific competition limits densification in the closed forest and seed limitation hinders densification in the single-tree tundra. We find striking differences in strength and timing of responses to recent climate warming. While forest-tundra stands recently densified, recruitment is almost non-existent at the southern and northern end of the ecotone due to autecological processes. Palaeo-treelines may therefore

  2. [Application of competition index in assessing intraspecific and interspecific spatial relations between manchurian ash and dahurian larch].

    PubMed

    Wang, Z; Wu, G; Wang, J

    2000-10-01

    The competition among trees within a stand includes aboveground and underground parts. How to determine the zone of competition influence is important for predicting tree growth. We divide the zone into two parts: one part is defined as inside radius, the distance from nearest competitors to subject tree, in which, the competition influence is the sum of both aboveground and underground; the another part is defined as outside radius, the distance of competitors to subject tree, where the competition influence comes mostly from underground. Thus, the competition index, based upon the divided two radii, could be decomposed into different components. We used the data of manchurian ash(MA) (Fraxinus mandshurica) and dahurian larch(DL) (Larix gmelini) from pure and mixed stands to analyze the competition influence of aboveground and underground in inside and of underground in outside radius. The results show that for MA in pure stand, the competition effect was 59.06% from inside radius, and 40.94% from outside radius. For DL in pure stand, the competition effects in both radii were 71.31% and 28.69%, respectively. There was a stronger competition influence in inside than in outside radius. Underground competitions were the important issues for both species in pure stands. In a mixed stand of MA and DL, there were two species in both radii, and the effects of competition came from intraspecific and interspecific competitors. For subject tree of MA, the effect of interspecific competition was 49.55%, and that of intraspecific was 50.45%. For subject tree of DL, the effects were 81.11% and 18.89%, respectively. DL displayed a stronger interspecific competition than MA in the zone of competition influence, and was a main effect of competition on MA. For subject tree of MA, the effect of competition from inside radius was 25.33%, which was the sum of competition influence from aboveground and underground, and about 74.67% was from outside radius. For subject tree of DL

  3. Terpenoid emissions from fully grown East Siberian Larix cajanderi trees

    NASA Astrophysics Data System (ADS)

    Kajos, M. K.; Hakola, H.; Holst, T.; Nieminen, T.; Tarvainen, V.; Maximov, T.; Petäjä, T.; Arneth, A.; Rinne, J.

    2013-03-01

    While emissions of many volatile compounds, such as terpenoids, have been studied quite intensively in North American and Scandinavian boreal forests, the vast Siberian boreal forests have remained largely unexplored by experimental emission studies. In this study the shoot scale terpenoid emission rates from mature Larix cajanderi trees growing in their natural habitat in Eastern Siberia were measured. Dynamic flow-through enclosure technique was applied for adsorbent sampling (Tenax-TA and Carbopack-B used as adsorbents), and the samples were analysed offline with a gas chromatograph. The emissions were dominated by monoterpenes, which constituted between 61 and 92% of the total emission. About half of the monoterpene emissions comprised of Δ3-carene; α- and β-pinene had significant emissions as well. Linalool emissions were also substantial, especially in June. Sesquiterpenes accounted for less than 3% and isoprene less than 1% of the total emissions. Based on the measured emission rates, the relative atmospheric concentration of each compound was estimated. Monoterpenes were the species with the highest relative concentration, while linalool and sesquiterpenes had a notably smaller contribution to the estimated atmospheric concentration than to the emission rates. Temperature dependent pool algorithm with a constant β (0.09 °C-1 for monoterpenes and 0.143 °C-1 for sesquiterpenes) was used to normalize the measured emission data. For monoterpenes the emission potential varied between 0.5-18.5 μg gdw-1 h-1 and for sesquiterpenes between 0.02 and 0.4 μg gdw-1 h-1.

  4. [CO2 flux characteristics and their influence on the carbon budget of a larch plantation in Maoershan region of Northeast China].

    PubMed

    Qiu, Ling; Zu, Yuan-Gang; Wang, Wen-Jie; Sun, Wei; Su, Dong-Xue; Zheng, Guang-Yu

    2011-01-01

    From January to December 2008, the CO2 flux in a larch plantation (Larix gmeilinii) in Maoershan region of Shangzhi County, Heilongliang Province was measured by eddy covanance method, and the diurnal changes of leaf photosynthetic rate were measured in growth season (from May to October). There existed differences in the net ecosystem exchange (NEE) of the plantation in different time periods under the effects of environmental factors. In the afternoon (12:00-24:00), the NEE changed more slowly with the variation of vapor pressure deficit (VPD) than in the morning (0:00-12:00); and in the morning, tbe light use efficiency was 0.6284 mol x mol(-1), 14% more than that in afternoon. The NEE increased with increasing temperature, and the increment in the morning was 50% higher than that in the afternoon (air temperature > 15 degrees C). These differences in responding to environmental changes led to 88% NEE implemented in the morning, and only 12% NEE implemented in the afternoon. The annual gross ecosystem productivity (GEP) in the morning took a percentage of 60%, and that in afternoon took 40%. These findings were supported by the observation at leaf level, i.e., on average of whole growth season, the leaf photosynthetic capacity in the morning was over 2-fold higher than that in afternoon. Generally, the annual NEE, ecosystem respiration (Re), and GEP of the plantation in 2008 were 263-264 g C x m(-2), 718-725 g C x m(-2), and 981-989 g C x m(-2), respectively.

  5. Terpenoid emissions from fully grown east Siberian Larix cajanderi trees

    NASA Astrophysics Data System (ADS)

    Kajos, M. K.; Hakola, H.; Holst, T.; Nieminen, T.; Tarvainen, V.; Maximov, T.; Petäjä, T.; Arneth, A.; Rinne, J.

    2013-07-01

    While emissions of many biogenic volatile organic compounds (BVOCs), such as terpenoids, have been studied quite intensively in North American and Scandinavian boreal forests, the vast Siberian boreal forests have remained largely unexplored by experimental emission studies. In this study the shoot-scale terpenoid emission rates from two mature Larix cajanderi trees growing in their natural habitat in eastern Siberia were measured at the Spasskaya Pad flux measurement site (62°15´18.4" N, 129°37´07.9" E) located on the western bank of the Lena river. The measurements were conducted during three campaigns: 3-24 June, 8-26 July, and 14-30 August, in the summer of 2009. A dynamic flow-through enclosure technique was applied for adsorbent sampling, and the samples were analysed offline with a gas chromatograph. Between 29 and 45 samples were taken from each shoot during all three campaigns. Seven different monoterpenes, six different sesquiterpenes, linalool isoprene, and 2-methyl-3-buten-2-ol (MBO) were identified. The monthly median value of the total terpenoid emissions varied between 0.006 and 10.6 μg gdw-1 h-1. The emissions were dominated by monoterpenes, which constituted between 61 and 92% of the total emissions. About half of the monoterpene emissions were comprised of Δ 3-carene; α- and β-pinene had significant emissions as well. Linalool emissions were also substantial, comprising 3-37% of the total emissions, especially in June. Sesquiterpenes accounted for less than 3% and isoprene less than 1% of the total emissions. Based on the measured emission rates, the relative atmospheric concentration of each compound was estimated. Monoterpenes were the species with the highest relative concentration, while linalool and sesquiterpenes had a notably smaller contribution to the estimated atmospheric concentration than to the emission rates. A temperature-dependent pool algorithm with a constant β (0.09 °C-1 for monoterpenes and 0.143 °C-1 for

  6. Stand-level factors associated with resurging mortality from eastern larch beetle (Dendroctonus simplex LeConte)

    Treesearch

    Susan J. Crocker; Greg C. Liknes; Fraser R. McKee; Jana S. Albers; Brian H. Aukema

    2016-01-01

    The current outbreak of eastern larch beetle (Dendroctonus simplex LeConte) in Minnesota, USA, ongoing since 2000, has been characterized with a severity and duration unprecedented in previous outbreaks within the state. This study investigates the relationship between tamarack mortality due to eastern larch beetle and extant stand and site...

  7. Tree-ring evidence for the historical absence of cyclic larch budmoth outbreaks in the Tatra Mountains

    Treesearch

    Oliver Konter; Jan Esper; Andrew Liebhold; Tomas Kyncl; Lea Schneider; Elisabeth Düthorn; Ulf. Buntgen

    2015-01-01

    The absence of larch budmoth outbreaks and subsequent consequences on tree rings together with a distinct climate–growth relationship enhance the dendroclimatic potential of larch ring width data from the Tatra Mountains. Regular population oscillations are generally considered to arise from trophic interactions, though it is unclear how such cycles are...

  8. Duff mound consumption and cambium injury for centuries-old western larch from prescribed burning in western Montana

    Treesearch

    Michael G. Harrington

    2012-01-01

    Western larch is one of the most fire-adapted conifers in western North America. Its historical perpetuation depended upon regular fire disturbances, which creates open stand conditions and mineral seedbeds. A stand of 200- to 500-year-old larch in western Montana with deep duff mounds resulting from an unusually long 150-year fire-free period was mechanically thinned...

  9. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65+degN). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 +/- 49 years (based on firescars) and 106 +/- 36 years (based on firescars and tree natality dates). FRIs were increased with latitude increase and observed to be about 80 years at 64N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approx.71+degN). Northward FRIs increase correlated with incoming solar radiation (r = -0.95). Post- Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. Keywords Fire ecology Fire history Fire frequency Siberian wildfires Larch forests Climate change

  10. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65+degN). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 +/- 49 years (based on firescars) and 106 +/- 36 years (based on firescars and tree natality dates). FRIs were increased with latitude increase and observed to be about 80 years at 64N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approx.71+degN). Northward FRIs increase correlated with incoming solar radiation (r = -0.95). Post- Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. Keywords Fire ecology Fire history Fire frequency Siberian wildfires Larch forests Climate change

  11. Flocculation of Microcystis aeruginosa using modified larch tannin.

    PubMed

    Wang, Li; Liang, Wenyan; Yu, Jian; Liang, Zhixia; Ruan, Lingling; Zhang, Yuanchun

    2013-06-04

    To flocculate the cyanobacterium Microcystis aeruginosa from water, larch tannin, a natural polymer, was modified by Mannich reaction to obtain a flocculant, named A-TN, which was then quaternized to yield another flocculant, named Q-TN. A-TN and Q-TN were characterized by Fourier transform infrared spectra (FTIR) and zeta potential analysis. The effects of the flocculation parameters, e.g., dosage, pH, cell density, culture time, and extracellular organic materials, were studied. The results showed that Q-TN was effective under a wider range of pH values than A-TN and could work under a pH of 9.0, whereas A-TN could work only under a pH of 7.0. For algal samples with densities from 1 × 10(8) to 5 × 10(9) cells/L, the optimum dosages of Q-TN to achieve more than 90% removal efficiency ranged from 0.5 to 20 mg/L, and the optimum dosages had a good linear relationship with cell density. Furthermore, the required dosage of Q-TN clearly increased along with the algae culture time, most of which was consumed by the extracellular organic materials (EOM) excreted from the cells. The spectra of the three-dimensional excitation-emission matrix showed that 100% of simple aromatic proteins and 78.8% of protein-like substances in the EOM could be removed by Q-TN. However, Q-TN was less effective in humic/fulvic-like substance flocculation. Q-TN functioned to settle the algae cells and a large amount of their metabolites effectively.

  12. Application of Ionic Liquids in the Microwave-Assisted Extraction of Proanthocyanidins from Larix gmelini Bark

    PubMed Central

    Yang, Lei; Sun, Xiaowei; Yang, Fengjian; Zhao, Chunjian; Zhang, Lin; Zu, Yuangang

    2012-01-01

    Ionic liquid based, microwave-assisted extraction (ILMAE) was successfully applied to the extraction of proanthocyanidins from Larix gmelini bark. In this work, in order to evaluate the performance of ionic liquids in the microwave-assisted extraction process, a series of 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were evaluated for extraction yield, and 1-butyl-3-methylimidazolium bromide was selected as the optimal solvent. In addition, the ILMAE procedure for the proanthocyanidins was optimized and compared with other conventional extraction techniques. Under the optimized conditions, satisfactory extraction yield of the proanthocyanidins was obtained. Relative to other methods, the proposed approach provided higher extraction yield and lower energy consumption. The Larix gmelini bark samples before and after extraction were analyzed by Thermal gravimetric analysis, Fourier-transform infrared spectroscopy and characterized by scanning electron microscopy. The results showed that the ILMAE method is a simple and efficient technique for sample preparation. PMID:22606036

  13. Biomass production of 4- to 9-year-old intensively cultured Larix eurolepis grown in

    Treesearch

    J. Zavitkovski; Allen L. Lundgren; Terry Strong

    1983-01-01

    Intensively cultured Larix eurolepis at age 9 averaged 7.6 m in height and, depending on the spacing, 2.3 to 6.4 cm in d.b.h. The total stem-branch biomass for all spacing tested (0.1 to 1.5 m2) averaged 67 mt/ha and the mean annual biomass increment 7.4 mt/ha. The "Scotch Plaid" design appears suitable for comparative studies dealing with spacing and...

  14. Biomass Production of 12-Year-Old Intensively Cultured Larix Eurolepis

    Treesearch

    Jerry Zavitkovski; Terry Strong

    1984-01-01

    Between 9 and 12 years Larix eurolepis grew annually about 1.3 m in height and 0.6 cm in diameter. In plots with 0.8 to 1.5 m(2) of growing space, total woody biomass increased from 70.1 to 98.8 mt/ha, and the mean annual biomass increment from 7.8 to 8.2 mt/ha.

  15. Significance of phytohormones in Siberian larch-bud gall midge interaction

    Treesearch

    Rida M. Matrenina

    1991-01-01

    Interrelations of the bud gall midge and the Siberian larch are of scientific and practical interest because of the bud gall midge's role as a plant endoparasite. We know that attack by the gall midge sets off a reaction in the entire plant. Invasion by the insect results in a certain interaction between physiological mechanisms of the insect and the plant which...

  16. Geographic variation, genetic structure, and conservation unit designation in the Larch Mountain salamander (Plethodon larselli).

    Treesearch

    R. Steven Wagner; Mark P. Miller; Charles M. Crisafulli; Susan M. Haig

    2005-01-01

    The Larch Mountain salamander (Plethodon larselli Burns, 1954) is an endemic species in the Pacific northwestern United States facing threats related to habitat destruction. To facilitate development of conservation strategies, we used DNA sequences and RAPDs (random amplified polymorphic DNA) to examine differences among populations of this...

  17. Response of larch root development to annual changes of water conditions in eastern Siberia

    NASA Astrophysics Data System (ADS)

    Takenaka, Chisato; Miyahara, Mie; Ohta, Takeshi; Maximov, Trofim C.

    2016-06-01

    Eastern Siberia is characterized by continuous permafrost, and has recently been exposed to the effects of climate change. Larch, which is the dominant tree species, has been subject to major environmental changes including fluctuations in soil water content. The purpose of this study was to clarify the responses of mature larch tree roots to changes in soil water conditions. We established a treatment plot in a larch forest, and artificially changed the soil water conditions by covering the ground surface with a vinyl sheet, and from 2004 to 2006 monitored root development through root windows. The vinyl sheet maintained high levels of soil water content, even though the ambient conditions varied from dry in 2004 to wet in 2005 and dry in 2006. In the treatment plot the plants adapted to the wet conditions by decreasing vertical root development. In contrast, roots of plants in the control plot developed to the subsurface layer, even in 2005, and did not develop vertically in 2006 despite the drought. We conclude that larch adapted to the annual changes in soil water content by changing the vertical distribution of roots, and that this reflected a memory effect.

  18. Guide to understory burning in ponderosa pine-larch-fir forests in the Intermountain West

    Treesearch

    Bruce M. Kilgore; George A. Curtis

    1987-01-01

    Summarizes the objectives, prescriptions, and techniques used in prescribed burning beneath the canopy of ponderosa pine stands, and stands of ponderosa pine mixed with western larch, Douglas-fir, and grand fir. Information was derived from 12 districts in two USDA Forest Service Regions and seven National Forests in Montana and Oregon.

  19. Preliminary guidelines for prescribed burning under standing timber in western larch/douglas-fir forests

    Treesearch

    Rodney A. Norum

    1977-01-01

    Guidelines are offered for safe, effective fire treatments in western larch/Douglas-fir forests. Describes procedures for estimating and limiting the scorching of tree crows. Provides a method for predicting percentage of the forest floor that will be burned down to mineral soil.

  20. The Seeley Lake larch: Living link to indian and frontier history

    Treesearch

    Stephen F. Arno

    2010-01-01

    Western Montana’s Big Blackfoot River was once the gateway to a magnificent forest and the conduit that fed an immense sawmill. Epic log drives once choked the waterway full of timber each spring. The Big Blackfoot drainage was known for its majestic, centuries-old ponderosa pine and western larch trees. Although stately old ponderosas were widely distributed across...

  1. Pest Risk Assessment of the Importation of Larch from Siberia and the Soviet Far East

    Treesearch

    USDA Forest Service

    1991-01-01

    Several timber companies in the United States have expressed an interest in importing unprocessed larch logs from Siberia and the Soviet Far East. A variety of exotic forest pests, including insects, nematodes, and fungi, can be transported on or in logs. Many of these organisms can survive in transit and have a high potential to colonize suitable hosts near ports of...

  2. Factors promoting larch dominance in Eastern Siberia: fire versus growth performance and implications for carbon dynamics

    NASA Astrophysics Data System (ADS)

    Schulze, E.-D.; Wirth, C.; Mollicone, D.; von Lüpke, N.; Ziegler, W.; Achard, F.; Mund, M.; Prokushkin, A.; Scherbina, S.

    2012-01-01

    The relative roles of fire and climate in determining canopy species composition and aboveground carbon stocks were investigated. Measurements were made along a transect extending from the dark taiga zone of Central Siberia, where Picea and Abies dominate the canopy, into the Larix zone of Eastern Siberia. We test the hypotheses that the change in canopy species composition is based (1) on climate-driven performance only, (2) on fire only, or (3) on fire-performance interactions. We show that the evergreen conifers Picea obovata and Abies sibirica are the natural late-successional species both in Central and Eastern Siberia, provided there has been no fire for an extended period of time. There are no changes in the climate-driven performance of the observed species. Fire appears to be the main factor explaining the dominance of Larix. Of lesser influence were longitude, hydrology and active-layer thickness. Stand-replacing fires decreased from 300 to 50 yr between the Yenisei Ridge and the upper Tunguska. Repeated non-stand-replacing surface fires eliminated the regeneration of Abies and Picea. With every 100 yr since the last fire, the percentage of Larix decreased by 20 %. Biomass of stems of single trees did not show signs of age-related decline. Relative diameter increment was 0.41 ± 0.20 % at breast height and stem volume increased linearly over time with a rate of about 0.36 t C ha-1 yr-1 independent of age class and species. Stand volumes reached about 130 t C ha-1 (equivalent to about 520 m3 ha-1). Individual trees of Larix were older than 600 yr. The maximum age and biomass seemed to be limited by fungal rot of heart wood. 60 % of old Larix and Picea and 30 % of Pinus sibirica trees were affected by stem rot. Implications for the future role of fire and of plant diseases are discussed.

  3. Seasonal Changes in Remote Vegetation Indices and Net Photosynthesis of Japanese Larch Needles

    NASA Astrophysics Data System (ADS)

    Nishida, K.; Nakaji, T.; Oguma, H.; Fujinuma, Y.

    2004-12-01

    We investigated the seasonal pattern of four kinds of remote vegetation indices (NDVI, PRI, [(1/rRedEdge)-(1/rNIR)] and [(1/rGreen)-(1/rNIR)]) and their correlation to photosynthetic activity in the needle leaves of Japanese larch. In the 42-year-old larch forest (Tomakomai, Japan), the diurnal courses of spectral reflectance and gas exchange rates of larch needles were periodically investigated during early June to late October in 2003. In the Tomakomai larch forest, expansion of short-shoot needles was started from mid-May, and yellow color change of the needle leaves was observed in late October. The seasonal pattern of index value differed among the vegetation indices. For example, daytime mean NDVI showed constant value from late June to early October. The [(1/rRedEdge)-(1/rNIR)] and PRI were increased during summer, and their peak were observed in July and August, respectively. Although the values of NDVI, PRI and [(1/rRedEdge)-(1/rNIR)] were depressed in late October with autumn senescence of the needles, the [(1/rGreen)-(1/rNIR)] in larch needles was not changed even in yellow colored needles. Consequently, correlation of these vegetation indices and seasonal changed photosynthetic parameters such as net photosynthetic rate (Pn) and photosynthetic light use efficiency (LUE) also differed among the indices. Although the PRI, NDVI and [(1/rRedEdge)-(1/rNIR)] positively correlated with daily maximum Pn and daily means of Pn and LUE, no correlation was found between [(1/rGreen)-(1/rNIR)] and the measured photosynthetic parameters. Based on the results of Pearson_fs correlation test, PRI and [(1/rRedEdge)-(1/rNIR)] were considered to be most useful index for the estimations of seasonal changes in Pn and LUE, respectively.

  4. [Characteristics of available P in the rhizosphere soil in pure Juglans mandshurica and Larix gmelinii and their mixed plantation].

    PubMed

    Chen, Yongliang; Han, Shijie; Zhou, Yumei; Zou, Chunjing; Zhang, Junhui

    2002-07-01

    The rhizosphere and non-rhizosphere soils were sampled in the pure and mixed plantations of Juglans mandshurica and Larix gmelinii by peeling the adhering soil of the roots, and the available P content were analyzed. The results showed that the available P content in the rhizosphere soil in the pure Larix gmelinii was 55.8% higher than that in the non-rhizosphere soil, while the available P content in the pure Juglans mandshurica was higher than that in the non-rhizosphere soil by 10.1%. The roots of Larix gmelinii had important effect on mobilizing P in the rhizosphere soil. The available P content in rhizosphere soil of Juglans mandshurica in the mixed plantation was higher than that in the pure plantation by 45.2% due to the effects of the roots of Larix gmelinii. The mechanism by which the available P content in the rhizosphere soil of Larix gmelinii was much higher was elucidated by means of P absorption, P desorption, and inorganic P gradation.

  5. Siberian larch forests and the ion content of thaw lakes form a geochemically functional entity.

    PubMed

    Herzschuh, Ulrike; Pestryakova, Luidmila A; Savelieva, Larissa A; Heinecke, Liv; Böhmer, Thomas; Biskaborn, Boris K; Andreev, Andrei; Ramisch, Arne; Shinneman, Avery L C; Birks, H John B

    2013-01-01

    Siberian larch forests growing on shallow permafrost soils have not, until now, been considered to be controlling the abiotic and biotic characteristics of the vast number of thaw-lake ecosystems. Here we show, using four independent data sets (a modern data set from 201 lakes from the tundra to taiga, and three lake-core records), that lake-water geochemistry in Yakutia is highly correlated with vegetation. Alkalinity increases with catchment forest density. We postulate that in this arid area, higher evapotranspiration in larch forests compared with that in the tundra vegetation leads to local salt accumulation in soils. Solutes are transported to nearby thaw lakes during rain events and snow melt, but are not fully transported into rivers, because there is no continuous groundwater flow within permafrost soils. This implies that potentially large shifts in the chemical characteristics of aquatic ecosystems to known warming are absent because of the slow response of catchment forests to climate change.

  6. Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Dvinskaya, Mariya L.; Petrov, Ilya A.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Fire history within the northern larch forests of Central Siberia was studied (65 + deg N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase and observed to be about 80 years at 64 deg N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approximately 71 deg + N). Northward FRI increase correlated with incoming solar radiation (r = -0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase.

  7. [The intensity of phytodetrite decomposition in Larch Forest of the permafrost zone in central Siberia].

    PubMed

    Prokushkin, S G; Prokushkin, A S; Sorokin, N D

    2014-01-01

    Based on the results of long-term investigations, quantitative assessment ofphytodetrite mineralization rates is provided. Their role in the biological cycle of larch stands growing in the permafrost zone of Central Evenkia is discussed. It is demonstrated that their destruction in the subshrub-sphagnum and cowberry-green moss larch stands is extremely slow, the plant litter contains the most cecalcitrant organic matter demonstrating the lowest decomposition coefficient of 0.03-0.04 year(-1), whereas fresh components of the plant litter have 3- to 4-fold higher values. An insignificant input of N and C from the analyzed mortmass to the soil has been registered. It has been revealed that the changes in N and C in the decomposition components are closely related to the quantitative dynamics (biomass) of microorganisms, such as hydrolytics and, especially, micromicetes.

  8. Results after 20 years from a western larch levels-of-growing-stock study.

    Treesearch

    K.W. Seidel

    1987-01-01

    The 20-year growth response from a levels-of-growing-stock study in an even-aged western larch stand in eastern Oregon, first thinned at age 33, showed that trees growing at low stand densities grew more rapidly in diameter than trees in high-density plots. Height growth was relatively uniform among density levels. Both basal-area and total cubic-volume increment...

  9. Variability in understory evapotranspiration with overstory density in Siberian larch forests

    NASA Astrophysics Data System (ADS)

    Tobio, A.; Loranty, M. M.; Kropp, H.; Pena, H., III; Alexander, H. D.; Natali, S.; Kholodov, A. L.

    2016-12-01

    Arctic ecosystems are changing rapidly in response to amplified rates of climate change. Increased vegetation productivity, altered ecosystem carbon and hydrologic cycling, and increased wildfire severity are among the key responses to changing permafrost and climate conditions. Boreal larch forests in northeastern Siberia are a critical but understudied ecosystem affected by these modifications. Understory vegetation in these ecosystems, which typically have low canopy cover, may account for half of all water fluxes. Despite the potential importance of the understory for ecosystem water exchange, there has been relatively little research examining variability in understory evapotranspiration in boreal larch forests. In particular, the water balance of understory shrubs and mosses is largely undefined and could provide insight on how understory vegetation and our changing climate interact. This is especially important because both observed increases in vegetation productivity and wildfire severity could lead to increases in forests density, altering the proportional contributions of over- and understory vegetation to whole ecosystem evapotranspiration. In order to better understand variability in understory evapotranspiration we measured in larch forests with differing overstory density and permafrost conditions that likely vary as a consequence of fire severity. We used the static chamber technique to measure fluxes across a range of understory vegetation types and environmental conditions. In general, we found that the understory vegetation in low density stands transpires more than that in high density stands. This tends to be correlated with a larger amount of aboveground biomass in the low density stands, and an increase in solar radiation, due to less shading by overstory trees. These results will help us to better understand water balances, evapotranspiration variability, and productivity changes associated with climate on understory vegetation. Additionally

  10. Study on adsorption and remediation of heavy metals by poplar and larch in contaminated soil.

    PubMed

    Wang, Xin; Jia, Youngfeng

    2010-08-01

    Field experiments at the Shenyang Experimental Station of Ecology were conducted to study the adsorption, accumulation, and remediation of heavy metals by poplar and larch grown in artificially contaminated soil. The soil was spiked with a combination of Cd, Cu, and Zn at concentrations of 1.5, 100, and 200 mg.kg(-1), respectively. The results showed that the biomass of poplar (Populus canadensis Moench) was lower by 26.0% in the soil spiked with a mixture of Cd, Cu, and Zn, compared with the control. Concentrations of Cd in poplar leaf and Cu in poplar roots in the treated soil were 4.11 and 14.55 mg kg(-1), respectively, which are much greater than in corresponding controls. The migration of heavy metals in woody plant body was in the order Cd > Zn > Cu. Poplar had higher metal concentrations in aboveground tissues and a higher biomass compared with larch of the same age and therefore is potentially more suitable for remediation. In the heavy metal-polluted soil of this study, phytoremediation by poplar may take 56 and 245 years for Cd and Cu, respectively, for meeting the soil standards of heavy metals, and the corresponding phytoremediation times by larch would take 211 and 438 years. The research findings could be used as a basis to develop ecological engineering technologies for environmental control and remediation of pollution caused by heavy metals in soils.

  11. [Effects of exotic Larix kaempferi on forest soil quality and bacterial diversity].

    PubMed

    Yang, Xin; Cao, Jing; Dong, Mao-Xing; Ma, Xiao-Jun

    2008-10-01

    The study on the soil quality and bacterial diversity under 8-30 years old exotic Larix kaempferi, native Pinus tabulaeformis, and secondary deciduous broadleaf forest stands in Xiaolong-shan Mountains of Gansu, Northwest China showed that the soil pH under different forest stands had no distinct variation, but soil moisture content was increased with increasing age of forest stands. Soil organic matter and nitrogen contents were the highest under secondary deciduous forest, followed by under L. kaermpferi, and P. tabulaeformis. However, the soils under different ages of forest stands had no obvious variations in their organic matter and nitrogen contents, suggesting that tree species was the main factor affecting soil quality. Compared with P. tabulaeformis, exotic L. kaempferi could significantly increase soil organic matter and nitrogen contents. PCR-DGGE banding patterns suggested that the soil under secondary deciduous broadleaf forest had the highest bacterial diversity, followed by under L. kaempferi, and P. tabulaeformis. The sequenced DGGE bands were classified into three bacterial groups, i. e., Proteobacteria, Cytophaga - Flavobacterium - Bacteroides, and high G + C content gram-positive type, among which, Proteobacteria occurred most frequently. Further detailed analyses suggested that the soil bacterial compositions under exotic Larix stands were more similar to each other than those under pine and secondary deciduous broadleaf forests. It was concluded that exotic L. kaempferi induced the changes of microbial diversity in the forest soils of this region.

  12. Variation in susceptibility to wind along the trunk of an isolated Larix kaempferi (Pinaceae) tree.

    PubMed

    Minamino, Ryoko; Tateno, Masaki

    2014-07-01

    • Premise of the study: The force of the wind is a significant hazard to the survival of trees and can affect tree morphology. However, the actual distribution of the stress that wind causes to a tree trunk is not well understood in spite of its expected importance to tree morphology. The uniform stress hypothesis (i.e., tree trunks take a form that equalizes the distribution of stress along the outer surface of the stem) has been tested indirectly as a model, placing high importance on the mechanical safety of a trunk, and rejected theoretically. But stress on a tree's trunk has not yet been measured directly.• Methods: Actual strains at the surface of the trunk of an isolated Larix kaempferi tree due to wind loads were measured at seven heights on the trunk for 1 yr.• Key results: During the measurement period, wind-induced stress was higher in the upper portions of the trunk than in the lower portions, regardless of wind speed, and the difference increased as wind speed increased. The deflection of the trunk recorded at each position was also larger in the upper portions than in the lower portions.• Conclusions: The results indicate that the upper portions of the trunk of an isolated Larix kaempferi tree are more susceptible to wind than are the lower portions. These results do not support the uniform stress hypothesis and suggest that another limitation (either mechanical or nonmechanical) acts on the morphology of the tree.

  13. [Aboveground biomass and nutrient distribution patterns of larch plantation in a montane region of eastern Liaoning Province, China].

    PubMed

    Yan, Tao; Zhu, Jiao-Jun; Yang, Kai; Yu, Li-Zhong

    2014-10-01

    Larch is the main timber species of forest plantations in North China. Imbalance in nutrient cycling in soil emerged due to single species composition and mono system structure of plantation. Thus it is necessary to grasp its biomass and nutrients allocation for scientific management and nutrient cycling studies of larch plantation. We measured aboveground biomass (stem, branch, bark and leaf) and nutrient concentrations (C, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn), and analyzed the patterns of accumulation and distribution of 19-year-old larch plantation with diameter at breast height of 12. 8 cm, tree height of 15. 3 m, and density of 2308 trees · hm(-2), in a montane region of eastern Liaoning Province, China. The results showed that aboveground biomass values were 70.26 kg and 162.16 t · hm(-2) for the individual tree of larch and the stand, respectively. There was a significant difference between biomass of the organs, and decreased in the order of stem > branch > bark > leaf. Nutrient accumulation was 749.94 g and 1730.86 kg · hm(-2) for the individual tree of larch and the stand, respectively. Nutrient accumulation of stem was significantly higher than that of branch, bark and leaf, whether it was macro-nutrient or micro-nutrient. Averagely, 749.94 g nutrient elements would be removed from the system when a 19-year-old larch tree was harvested. If only the stem part was removed from the system, the removal of nutrient elements could be reduced by 40.7%.

  14. Isolation and identification of chitin in the black coral Parantipathes larix (Anthozoa: Cnidaria).

    PubMed

    Bo, Marzia; Bavestrello, Giorgio; Kurek, Denis; Paasch, Silvia; Brunner, Eike; Born, René; Galli, Roberta; Stelling, Allison L; Sivkov, Viktor N; Petrova, Olga V; Vyalikh, Denis; Kummer, Kurt; Molodtsov, Serguei L; Nowak, Dorota; Nowak, Jakub; Ehrlich, Hermann

    2012-01-01

    Until now, there is a lack of knowledge about the presence of chitin in numerous representatives of corals (Cnidaria). However, investigations concerning the chitin-based skeletal organization in different coral taxa are significant from biochemical, structural, developmental, ecological and evolutionary points of view. In this paper, we present a thorough screening for the presence of chitin within the skeletal formations of a poorly investigated Mediterranean black coral, Parantipathes larix (Esper, 1792), as a typical representative of the Schizopathidae family. Using a wide array variety of techniques ((13)C solid state NMR, Fourier transform infrared (FTIR), Raman, NEXAFS, Morgan-Elson assay and Calcofluor White Staining), we unambiguously show for the first time that chitin is an important component within the skeletal stalks as well as pinnules of this coral. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. [Spatial distribution pattern and fractal analysis of Larix chinensis populations in Qinling Mountain].

    PubMed

    Guo, Hua; Wang, Xiaoan; Xiao, Yaping

    2005-02-01

    In this paper, the fractal characters of Larix chinensis populations in Qinling Mountain were studied by contiguous grid quadrate sampling method and by boxing-counting dimension and information dimension. The results showed that the high boxing-counting dimension (1.8087) and information dimension (1.7931) reflected a higher spatial occupational degree of L. chinensis populations. Judged by the dispersal index and Morisita's pattern index, L. chinensis populations clumped at three different age stages (0-25, 25-50 and over 50 years). From Greig-Smiths' mean variance analysis, the figure of pattern scale showed that L. chinensis populations clumped in 128 m2 and 512 m2, and the different age groups clumped in different scales. The pattern intensities decreased with increasing age, and tended to reduce with increasing area when detected by Kershaw's PI index. The spatial pattern characters of L. chinensis populations may be their responses to environmental factors.

  16. Post-fire stand structure impacts carbon storage within Siberian larch forests

    NASA Astrophysics Data System (ADS)

    Alexander, H. D.; Natali, S.; Loranty, M. M.; Mack, M. C.; Davydov, S. P.; Zimov, N.

    2015-12-01

    Increased fire severity within boreal forests of the Siberian Arctic has the potential to alter forest stand development thereby altering carbon (C) accumulation rates and storage during the post-fire successional interval. One potential change is increased stand density, which may result from fire consumption of the soil organic layer and changes to the seedbed that favor germination and establishment of larch trees during early succession. In this study, we evaluated above- and belowground C pools across 12 stands of varying tree density within a single 75-year old fire scar located near Cherskii, Sakha Republic, Russia. In each stand, we inventoried the size and density of larch trees and large shrubs (Salix and Betula spp.), and in combination with with allometric equations, estimated aboveground contribution to C pools. We quantified woody debris C pools using the line intercept method. We sampled belowground C pools in the soil organic layer + upper (0-10 cm) mineral soil and coarse roots (> 2 mm diameter) using sediment cores and 0.25 x 0.25-m trenches, respectively. We found that high density stands store ~ 20% more C (~7,500 g C m-2) than low density stands (~5,800 g C m-2). In high density stands, about 35% more C is stored aboveground within live larch trees (1650 g C m-2) compared to low density stands (940 g C m-2), and about 15% more C is stored in the soil organic layer and upper mineral soil. Coarse root C was 20% higher in high density stands (~475 g C m-2) compared to those with low density (~350 g C m-2). Less C was stored in large shrubs in high density stands, both in aboveground portions and coarse roots, but these amounts were relatively small (< 10% of total C pools). A fire-driven shift to denser larch stands could increase C storage, leading to a negative feedback to climate, but the combined effects of density on C dynamics, summer and winter albedo, and future fire regimes will interact to determine the magnitude of any vegetation

  17. Changing Boreal Fire Regimes: Impacts on Permafrost Soils and Forest Succession in Siberian Larch Forests

    NASA Astrophysics Data System (ADS)

    Alexander, H. D.; Mack, M. C.; Natali, S.; Loranty, M. M.; Davydov, S. P.; Zimov, N.

    2014-12-01

    Fire activity has increased across the boreal forest biome in conjuction with climate warming and drying. Because these forests contain a large proportion of global terrestrial carbon (C) stocks, there has been great interest in understanding feedbacks between a changing fire regime and climate warming. An important mechanism by which increased fire activity may alter boreal C balance is by consuming the soil organic layer (SOL). Fire removal of the SOL may alter germination microsites and tree recruitment, thereby altering forest successional trajectories and C accumulation and storage. In permafrost soils, loss of the insulating SOL can increase soil temperature and active layer depth, impacting growth and survival conditions for both soil microbes and vegetation. To assess fire severity effects on permafrost soils and tree recruitment, we conducted plot-level experimental burns in July 2012 in a larch forest near Cherskii, Siberia. We achieved four burn severity treatments based on residual SOL depths: control, low (> 8 cm), moderate (5-8 cm), and high severity (2-5 cm). For two growing seasons post-fire, we measured thaw depth, soil moisture, and soil temperature. We sowed larch seeds in fall 2012 and 2013 and quantified seedling establishment and vegetation re-growth for two growing seasons. Immediately post-fire, thaw depth increased rapidly with increasing fire severity, and this trend has persisted for two years. In 2013 and 2014, thaw depth was ~ 40 cm deeper in high severity plots compared to controls, likely due to lower summer soil insulation, higher black char cover, and higher surface soil temperatures. We observed little to no larch recruitment in unburned and low severity plots, but new seedling density was ~5 seedlings m-2 in moderate and high severity plots, which had low cover of other vegetation types and high soil moisture. Findings suggest that increased fire severity may increase larch recruitment and provide favorable soil conditions for

  18. Energy and carbon balances with phenology over the larch forests on the permafrost in northern Mongolia

    NASA Astrophysics Data System (ADS)

    Miyazaki, S.; Ishikawa, M.; Nachin, B.; Sodov, D.; Yamkhin, J.

    2012-12-01

    To clarify the heat, water carbon exchange process and dynamics by comprehensive approach, we've carried out the long term monitoring of the energy and carbon balances, the hydro-climatic, the phonological camera monitoring and sap flow measurement at the 25-m height tower and larch forest around the tower in the Udleg (48 15'43.7" N, 106 50'56.6"E, altitude: 1264m) in permafrost area of northern Mongolia since 2010. The annual range of air temperature and annual mean air temperature were about 60 degree C and -1 degree C, respectively. The annual precipitation was about 250 mm with about 90% of it from May to September. According to the image analysis of in situ camera and PAR albedo data, we clarified the seasonal variation of surface condition and phenology of larch forest. From January to March, November and December, there was continuous snow cover on the surface when the PAR albedo was about 0.15 to 0.2. In late May the leaf of larch emerged and attained the mature growth in July, and then the leaf senescence occurred in mid September. The PAR albedo shows abrupt decrease in late May and abrupt increase in mid September that coincides with the leaf emergence and senescence. The soil moisture at 10 cm depth was less than 10% before April, then it gradually increase in May to 20% in August, after that it decreases to less than 10% from October. The temporal variation of soil moisture matched to temporal variation of rainfall. The soil temperature below 3m was about -0.2 degree C in all year round that suggests that there is the permafrost. In late May the latent heat flux start to increase with soil moisture and become dominant component of energy fluxes from mid June to early September when the carbon uptake was active. From mid September to early June, the sensible heat flux was dominant component of energy fluxes when the surface was carbon source. We found that the close relationship between phenology (leaf emergence, growth and senescence) of larch trees

  19. Synthesis of nickel-incorporated larch-based carbon membranes with controllable porous structure for gas separation

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Li, Wei; Huang, Zhanhua; Liu, Shouxin

    2015-11-01

    Ni-incorporated larch-based carbon membranes have been synthesized by introducing the Ni(NO3)2 into the liquefied larch using liquefied larch sawdust as precursors and F127 as the soft template. The porous structure can be tailored by the amount of Ni(NO3)2, and the Ni and NiO nanoparticles with a size of 10 nm incorporated in the carbon frameworks. The increase in Ni(NO3)2 content can lead to the formation of disordered porous structure and shrinkage of carbon frameworks. The Ni-incorporated carbon membranes with largest pores possess highest gas permeation for N2, CO2, and O2 of 37.5, 19.8, and 55.5 m3 cm/m2 h kPa, which is larger than that of the pure carbon membranes, respectively. However, the poor ordered porous structure caused by adding large amount of Ni(NO3)2 can reduce the gas separation performance, which is attributed to the weaken of the molecular sieve function. The results indicate that the incorporation of few nanoparticles into larch-based carbon membranes can improve molecular sieve function.

  20. Growth and yield of western larch under controlled levels of stocking in the Blue Mountains of Oregon.

    Treesearch

    P.H. Cochran; K.W. Seidel

    1999-01-01

    Repeated thinning to five growing-stock levels resulted in widely differing tree sizes and volumes per acre after 30 years. Largest trees but the least cubic-volume yield per acre were produced in the heaviest thinning level, whereas highest board-foot yields were found in intermediate thinning levels. Partial defoliation by larch casebearer (Coleophora...

  1. [Postfire restoration of organic substance in the ground cover of the larch forests in the permafrost zone of central Evenkia].

    PubMed

    Prokushkin, S G; Bogdanov, V V; Prokushkin, A S; Tokareva, I V

    2011-01-01

    The role of ground fires in transformation of organic substances in the ground cover of larch stands in the permafrost zone of Central Siberia was studied, as was the postfire restoration dynamics of organic substances. Ground fires lead to a considerable decrease in concentrations and resources of organic carbon and its individual fractions in the ground cover, and restoration takes many decades.

  2. Old growth ponderosa pine and western larch stand structures: Influences of pre-1900 fires and fire exclusion. Forest Service research paper

    SciTech Connect

    Arno, S.F.; Smith, H.Y.; Krebs, M.A.

    1997-02-01

    We present data from two old growth stands on Lolo National Forest representing habitats that contrast with larch stand. One of the stands is a mixture of pine and larch on a steep upland slope and the other is larch dominated in a frost-prone valley bottom evidently at the cold limits of ponderosa pine. We also synthesize and compare age-class data, basal areas (BA), and Stand Density Indexes (SDI) for the entire range of old growth stands that we have sampled to represent the historical frequent fire types in western Montana.

  3. The effects of doubling annual N and S deposition on foliage and soil chemistry and growth of Japanese larch (Larix leptolepis Sieb. and Zucc.) in north central West Virginia

    Treesearch

    Callie J. Pickens; William E. Sharpe; Pamela J. Edwards

    1995-01-01

    Atmospheric deposition has been recognized as a significant environmental problem for several decades, but its impact on forest ecosystems in North America remains controversial. In an effort to further elucidate the impacts of atmospheric deposition to forested watersheds in the Mid-Appalachian region, several related watershed studies have been initiated by the U.S....

  4. Role of understory vegetation in decadal variation of water and carbon dioxide exchange over larch forest of eastern Siberia

    NASA Astrophysics Data System (ADS)

    Kotani, Ayumi; Ohta, Takeshi; Iijima, Yoshihiro; Maximov, Trofim

    2016-04-01

    This study investigated evapotranspiration and carbon dioxide exchange by the eddy covariance methods over larch-dominated forests in the middle part of the Lena basin, eastern Siberia. Forest ecosystem in this region is characterized by low precipitation, a short growing season, and extensive permafrost. Seasonal thawing permafrost supplies soil water, which is prevented to infiltrating by an impermeable frozen layer, and supports forest development. A decadal observation of hydro-meteorological variables shows inter-annual variability including extreme environmental conditions such as unusually wet active layer, which was maintained for a few years. Some mature larch trees locating poor drainage area suffered wet damage, while young birch and willow trees developed and herbs with water tolerance expanded. Compared to fluxes of the whole ecosystem, those based on the understory layer changed through the study period due to increase biomass and change of inside canopy environments; plentiful light and soil water, and enhanced turbulent mixing. Evapotranspiration from the understory layer increased and contribution to the whole forest flux reached 60%. Although this layer always acts as carbon dioxide source in seasonal average through the study period, source strength weaken and changed to temporal sink in the early summer. On contrast, contribution of the larch layer, in spite of remaining uncertainty in quantity, decreased in both of evapotranspiration and carbon dioxide uptake. Interactions between larch and understory support maintenance of this forest ecosystem. Decline of larch contribution is made up by understory growing, resulting in relatively stable whole forest exchange rate at least until this wet event.

  5. Variability in above- and belowground carbon stocks in a Siberian larch watershed

    NASA Astrophysics Data System (ADS)

    Webb, Elizabeth E.; Heard, Kathryn; Natali, Susan M.; Bunn, Andrew G.; Alexander, Heather D.; Berner, Logan T.; Kholodov, Alexander; Loranty, Michael M.; Schade, John D.; Spektor, Valentin; Zimov, Nikita

    2017-09-01

    Permafrost soils store between 1330 and 1580 Pg carbon (C), which is 3 times the amount of C in global vegetation, almost twice the amount of C in the atmosphere, and half of the global soil organic C pool. Despite the massive amount of C in permafrost, estimates of soil C storage in the high-latitude permafrost region are highly uncertain, primarily due to undersampling at all spatial scales; circumpolar soil C estimates lack sufficient continental spatial diversity, regional intensity, and replication at the field-site level. Siberian forests are particularly undersampled, yet the larch forests that dominate this region may store more than twice as much soil C as all other boreal forest types in the continuous permafrost zone combined. Here we present above- and belowground C stocks from 20 sites representing a gradient of stand age and structure in a larch watershed of the Kolyma River, near Chersky, Sakha Republic, Russia. We found that the majority of C stored in the top 1 m of the watershed was stored belowground (92 %), with 19 % in the top 10 cm of soil and 40 % in the top 30 cm. Carbon was more variable in surface soils (10 cm; coefficient of variation (CV) = 0.35 between stands) than in the top 30 cm (CV = 0.14) or soil profile to 1 m (CV = 0.20). Combined active-layer and deep frozen deposits (surface - 15 m) contained 205 kg C m-2 (yedoma, non-ice wedge) and 331 kg C m-2 (alas), which, even when accounting for landscape-level ice content, is an order of magnitude more C than that stored in the top meter of soil and 2 orders of magnitude more C than in aboveground biomass. Aboveground biomass was composed of primarily larch (53 %) but also included understory vegetation (30 %), woody debris (11 %) and snag (6 %) biomass. While aboveground biomass contained relatively little (8 %) of the C stocks in the watershed, aboveground processes were linked to thaw depth and belowground C storage. Thaw depth was negatively related to stand age, and soil C density

  6. Variability in Albedo Associated with Fire-Mediated Controls on Stand Density in Siberian Larch Forests

    NASA Astrophysics Data System (ADS)

    Loranty, M. M.; Fullmer, J.; Nguyen, C. L.; Alexander, H. D.; Natali, S.; Bunn, A. G.; Davydov, S. P.; Goetz, S. J.; Mack, M. C.

    2015-12-01

    Fire is an integral component of boreal forests, and exerts strong control over ecosystem structure and function. The frequency and spatial extent of fire controls the age-class distribution of forests on the landscape. In addition, recent evidence from North American boreal forests has show that fire severity influences post-fire succession via impacts on seedling recruitment that manifest in mature ecosystems dominated by either deciduous or coniferous tree species. The effects of fire on ecosystem structure have important climate feedback implications; changes in forest density or leaf habit can influence surface net radiation by altering the snow-masking effects of vegetation. Although Siberian larch forests occupy a more than 2.8 million km2 of the boreal biome, and are the most prevalent forests in Russia, the influence of fire severity on succession and associated surface energy dynamics are less well understood in comparison to North American boreal forests. There is evidence suggesting that increased fire severity may lead to higher density of post-fire regrowth, but the influence of stand density on surface energy dynamics remains poorly quantified. Here, we quantify the effects of stand density on albedo across the Kolyma River basin using satellite-derived albedo and fire history in conjunction with maps and field observations of ecosystem structure. During snow-free periods albedo varies little with stand density. During periods of snow cover we find consistent negative correlations between multiple metrics of canopy cover and albedo. Albedo decreased with fire recovery over the forty-year fire record for the study area. However, the range of albedo observed within individual fire scars was similar to the magnitude of albedo recovery during the study period. This result indicates the importance of variability in post-fire regrowth within individual fire scars, potentially associated with fire severity, for understanding fire effects on surface energy

  7. Extraction of dihydroquercetin from Larix gmelinii with ultrasound-assisted and microwave-assisted alternant digestion.

    PubMed

    Ma, Chunhui; Yang, Lei; Wang, Wenjie; Yang, Fengjian; Zhao, Chunjian; Zu, Yuangang

    2012-01-01

    An ultrasound and microwave assisted alternant extraction method (UMAE) was applied for extracting dihydroquercetin (DHQ) from Larix gmelinii wood. This investigation was conducted using 60% ethanol as solvent, 1:12 solid to liquid ratio, and 3 h soaking time. The optimum treatment time was ultrasound 40 min, microwave 20 min, respectively, and the extraction was performed once. Under the optimized conditions, satisfactory extraction yield of the target analyte was obtained. Relative to ultrasound-assisted or microwave-assisted method, the proposed approach provides higher extraction yield. The effect of DHQ of different concentrations and synthetic antioxidants on oxidative stability in soy bean oil stored for 20 days at different temperatures (25 °C and 60 °C) was compared. DHQ was more effective in restraining soy bean oil oxidation, and a dose-response relationship was observed. The antioxidant activity of DHQ was a little stronger than that of BHA and BHT. Soy bean oil supplemented with 0.08 mg/g DHQ exhibited favorable antioxidant effects and is preferable for effectively avoiding oxidation. The L. gmelinii wood samples before and after extraction were characterized by scanning electron microscopy. The results showed that the UMAE method is a simple and efficient technique for sample preparation.

  8. Nuclear and cytoplasmic changes associated with maturation in the vascular cambium of Larix laricina.

    PubMed

    Mellerowicz, E. J.; Riding, R. T.; Greenwood, M. S.

    1995-01-01

    We studied the effects of apical maturation on the vascular cambium of juvenile and mature scions of Larix laricina (Du Roi) K. Koch that had been grafted on seedling rootstocks. Comparisons between the juvenile and mature cambium in nuclear genome size, nuclear shape, DNA concentration, number and volume of nucleoli per nucleus, and concentration of extranuclear RNAs, proteins and insoluble carbohydrates were conducted on four occasions during the annual cycle of cambial activity and dormancy. All investigated variables exhibited strong annual oscillations, whereas differences between the two maturation stages were less prominent. Many of the differences between the two phases could be explained by delayed spring reactivation and accelerated onset of dormancy in the mature cambium compared with the juvenile cambium. At the time of reactivation and during activity, the mature cambium exhibited lower genome size, lower DNA concentration, fewer nucleoli per nucleus and a higher extranuclear concentration of insoluble carbohydrates than the juvenile cambium. The dormant mature cambium contained more extranuclear RNAs than the dormant juvenile cambium. The observed differences provide circumstantial evidence of changes in chromatin organization or functioning, or both, during maturation.

  9. Responses of black spruce (Picea mariana) and tamarack (Larix laricina) to flooding and ethylene.

    PubMed

    Islam, M Anisul; MacDonald, S Ellen; Zwiazek, Janusz J

    2003-06-01

    Black spruce (Picea mariana (Mill.) BSP) and tamarack (Larix laricina (Du Roi) K. Koch) are the predominant tree species in the boreal peatlands of Alberta, Canada, where low nutrient availability, low soil temperature and a high water table limit their growth. Effects of flooding for 28 days on morphological and physiological responses were investigated in greenhouse-grown black spruce and tamarack seedlings in a growth chamber. Flooding reduced root hydraulic conductance, net assimilation rate and stomatal conductance, and increased water-use efficiency (WUE) and needle electrolyte leakage in both species. Although flooded black spruce seedlings maintained higher net assimilation rates and stomatal conductance than flooded tamarack seedlings, flooded tamarack seedlings were able to maintain higher root hydraulic conductance than flooded black spruce seedlings. Needles of flooded black spruce developed tip necrosis and electrolyte leakage after 14 days of flooding, and these symptoms were subsequently more prominent than in needles of flooded tamarack seedlings. Flooded tamarack seedlings exhibited no visible injury symptoms and developed hypertrophied lenticels at their stem base. Application of exogenous ethylene resulted in a significant reduction in net assimilation, stomatal conductance and root respiration, whereas root hydraulic conductivity increased in both species. Thus, although flooded black spruce seedlings maintained a higher stomatal conductance and net assimilation rate than tamarack seedlings, black spruce did not cope with the deleterious effects of prolonged soil flooding and exogenous ethylene as well as tamarack.

  10. [Vegetation carbon storage in Larix gmelinii plantations in Great Xing' an Mountains].

    PubMed

    Qi, Guang; Wang, Qing-Li; Wang, Xin-Chuang; Qi, Lin; Wang, Qing-Wei; Ye, Yu-Jing; Dai, Li-Min

    2011-02-01

    Through sampling site investigation, this paper studied the carbon storage of arbor, herb, and whole vegetation in 10-, 12-, 15-, 26-, and 61-year old Larix gmelinii plantations in Huzhong Forestry Bureau of Great Xing' an Mountains, Northeast China, and 'temporal for spatial' method was employed to approach the variations of the vegetation carbon storage during the growth of the plantations. The results revealed that the vegetation carbon storage in the plantations increased with stand age, and reached 105.69 t x hm(-2) at age of 61 years, representing a marked role as a carbon sink. The L. gmelinii plantations at the ages from 15 to 26 years had the strongest capability in carbon sequestration, in which, the carbon storage in trunk occupied 54.3% -73.9% of the total carbon storage of arbor, and, with the increase of stand age, the trunk's carbon storage to the total carbon storage of arbor as well as the trunk's carbon density increased. As for the other organs, the rate of their carbon storage to the total carbon storage of arbor decreased with stand age, while their carbon density increased first but eventually leveled off or had a slight decrease till at age of 61 years. Based on these results, the rotation age for the L. gmelinii plantations in Great Xing' an Mountains would properly be lengthened to at least 60 years.

  11. [Effects of compaction on diurnal variaaton of soil respiration in Larix gmellini plantation in summer].

    PubMed

    He, Na; Wang, Li-hai

    2010-12-01

    Taking the Larix gmellinii plantation in the experimental forest farm of Northeast Forestry University as test object, and by using Li-8100 automatic instrument, the daily CO2 emission rate of soil in summer under different degrees of man-made compaction was measured, with the regression models established. There were significant differences in the diurnal variation of soil respiration rate under different degrees of man-made compaction. In CK (no compaction), the maximum value of soil respiration appeared at 15:30-17:30, and the minimum value appeared at 03:30-05:30, which were obviously lagged behind those in compaction treatments. The maximum and minimum values of soil respiration rate in main roads appeared at 09:30-11:30 and 23:30-01:30, and those in branch roads appeared at 11:30 and 01:30-03:30, respectively. In all treatments, soil respiration rate had significant correlations with surface temperature, relative humidity, and the temperature at 10 cm soil depth, but the correlation with the soil moisture at 5 cm depth tended to be not significant when the compaction degree was increasing. Compaction altered surface soil physical structure, decreased surface soil CO2 release rate.

  12. [Obstacles for natural regeneration of Larix olgensis plantations in montane regions of eastern Liaoning Province, China].

    PubMed

    Zhu, Jiao-jun; Liu, Zu-gen; Wang, He-xin

    2008-04-01

    Based on the field investigations about the seed bank, seed germination, seedling emergence, and seedling survival and growth in the Larix olgensis plantations with different thinning intensities and various ground preparations in the montane regions of eastern Liaoning Province, the main factors affecting the natural regeneration of L. olgensis were analyzed in this paper. The results showed that in the seed rain of 40 years old L. olgensis plantation, 30% of the seeds had viability, which could meet the needs of natural regeneration. The seeds in soil seed bank mainly distributed in litter layer, and the seedlings younger than one-year old emerged in April and reached the peak in June. The accumulative emergence rate of the seedlings had no significant correlation with thinning intensities, but was affected by ground preparations. The average survival rate of appeared seedlings increased with increasing thinning intensities, but the seedling growth was generally slow in the plantation stands, e.g., the seedling height was less than 6 cm, and most of the seedlings disappeared in September. In the plantation stands, it was difficult to find the L. olgensis seedlings elder than one-year; but in the clear-cut area with enough light and less ground cover, more seedlings could survive and grew well. Based on the above mentioned results, it was concluded that the main obstacles for the natural regeneration of L. olgensis plantations in montane regions of eastern Liaoning Province could be light intensity and ground cover.

  13. Homogalacturonan deesterification during pollen-ovule interaction in Larix decidua Mill.: an immunocytochemical study.

    PubMed

    Rafińska, Katarzyna; Świdziński, Michał; Bednarska-Kozakiewicz, Elżbieta

    2014-07-01

    Studies on angiosperm plants have shown that homogalacturonan present in the extracellular matrix of pistils plays an important role in the interaction with the male gametophyte. However, in gymnosperms, knowledge on the participation of HG in the pollen-ovule interaction is limited, and only a few studies on male gametophytes have been reported. Thus, the aim of this study was to determine the distribution of HG in male gametophytes and ovules during their interaction in Larix decidua Mill. The distribution of HG in pollen grains and unpollinated and pollinated ovules was investigated by immunofluorescence techniques using monoclonal antibodies that recognise high methyl-esterified HG (JIM7), low methyl-esterified HG (JIM5) and calcium cross-linked HG (2F4). All studied categories of HG were detected in the ovule. Highly methyl-esterified HG was present in the cell walls of all cells throughout the interaction; however, the distribution of low methyl-esterified and calcium cross-linked HG changed during the course of interaction. Both of these categories of HG appeared only in the apoplast and the extracellular matrix of the ovule tissues, which interact with the male gametophyte. This finding suggests that in L. decidua, low methyl-esterified and calcium cross-linked HG play an important role in pollen-ovule interaction. The last category of HG is most likely involved in adhesion between the pollen and the ovule and might provide an optimal calcium environment for pollen grain germination and pollen tube growth.

  14. Traumatic resin ducts in Larix decidua stems impacted by debris flows.

    PubMed

    Bollschweiler, Michelle; Stoffel, Markus; Schneuwly, Dominique M; Bourqui, Karin

    2008-02-01

    Following mechanical injury, stems of many conifers produce tangential rows of traumatic resin ducts (TRDs), the distribution of which has been used to date geomorphic events. However, little is known about how far TRD formation extends tangentially and axially from the point of injury or what the time course of TRD appearance is. We analyzed 28 injuries in eight Larix decidua Mill. tree stems resulting from debris flows in October 2000 and November 2004. Injuries occurred outside the period of cambial activity, and TRD formation occurred in the first layers of the growth ring formed in the year following that of injury. The axial extent of TRD formation averaged 74 cm and was greater above the injury than below it. At the height of the wound center, TRDs extended horizontally to a mean of 18% of the stem circumference excluding that portion where the cambium had been destroyed. In subsequent growth rings, TRDs, if present, were confined mainly to the height of the center of injury. Both the vertical and horizontal extent of TRD formation was related to the injury size. Within growth rings, the position of TRD formation changed with increasing distance from the wound progressing from early earlywood to later portions of the growth ring.

  15. [Effects of fertilization on nutrient concentrations of different root orders' fine roots in Larix kaempferi plantation].

    PubMed

    Yu, Li-Zhong; Ding, Guo-Quan; Zhu, Jiao-Jun; Zhang, Na; Zhang, Xiao-Peng; Ying, Hui

    2009-04-01

    With the 16 years old Larix kaempferi plantation in eastern mountain area of Liaoning Province, China as test object, this paper studied the effects of fertilization on the nutrient concentrations of five root orders' fine roots. Under fertilization, less difference was observed in the total C concentration of the fine roots. Among the five orders' fine roots, the first order's had the lowest concentration of non-structural carbohydrate (TNC) and the highest ones of N and P, while the fifth order's was in adverse. The TNC concentration increased with increasing root order, while the N and P concentrations decreased correspondingly. Fertilization only had significant effects on the N and P concentrations of the first order's fine roots. The C/N/P ratio in different orders' fine roots had significant differences, being 423 : 16 : 1 and 726 : 16 : 1 in the first and the fifth order's fine roots, respectively. With the increase of root order, the proportion of C increased significantly, while that of N varied little. N fertilization didn't change the proportion of C, while P or P + N fertilization decreased the proportions of C and N in the first three orders' fine roots at 0-10 cm soil depth or in the first two orders' fine roots at 10-20 cm soil depth.

  16. Extraction of Dihydroquercetin from Larix gmelinii with Ultrasound-Assisted and Microwave-Assisted Alternant Digestion

    PubMed Central

    Ma, Chunhui; Yang, Lei; Wang, Wenjie; Yang, Fengjian; Zhao, Chunjian; Zu, Yuangang

    2012-01-01

    An ultrasound and microwave assisted alternant extraction method (UMAE) was applied for extracting dihydroquercetin (DHQ) from Larix gmelinii wood. This investigation was conducted using 60% ethanol as solvent, 1:12 solid to liquid ratio, and 3 h soaking time. The optimum treatment time was ultrasound 40 min, microwave 20 min, respectively, and the extraction was performed once. Under the optimized conditions, satisfactory extraction yield of the target analyte was obtained. Relative to ultrasound-assisted or microwave-assisted method, the proposed approach provides higher extraction yield. The effect of DHQ of different concentrations and synthetic antioxidants on oxidative stability in soy bean oil stored for 20 days at different temperatures (25 °C and 60 °C) was compared. DHQ was more effective in restraining soy bean oil oxidation, and a dose-response relationship was observed. The antioxidant activity of DHQ was a little stronger than that of BHA and BHT. Soy bean oil supplemented with 0.08 mg/g DHQ exhibited favorable antioxidant effects and is preferable for effectively avoiding oxidation. The L. gmelinii wood samples before and after extraction were characterized by scanning electron microscopy. The results showed that the UMAE method is a simple and efficient technique for sample preparation. PMID:22942735

  17. Growth dynamics and biodiversity of larch forest after wildfire at the north of central Siberia

    SciTech Connect

    Danilin, I.

    1996-12-31

    Investigations of qualitative and quantitative changes occurring in disturbed forest communities in Siberia are now recognized as important issues, since anthropogenic stress is increasingly affecting forests from year to year and often results in irreversible decomposition of forest ecosystems over large areas. In forests of central Siberia, fire accounts for the greatest disturbance. The level of fire-caused forest destruction is noticeably high. Space imagery analysis has revealed that, from 1980 throughout 1995, the average annual forest area covered by fires was more than 500,000 ha. In as much as this is a country with permafrost soils, fires promote swamping and treeless areas. However, forests regenerate naturally on some burned areas. Forest regeneration can occur either with stand replacement (through secondary birch) or without replacement when new forests are formed by the pre-fire edificators. The second way of succession is ecologically more preferable, because the larch population is more resistant to external influences and keeps its native biodiversity.

  18. 31. View of the French lot, looking southeast, with the ...

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

    31. View of the French lot, looking southeast, with the summit of Mount Ascutney (elevation 3150 ft.) on the distant horizon at left. The meadow is flanked by a historic plantation of Norway spruce (Picea abies), dated 1887, at right; and a plantation of European larch (Larix decidua), also dated 1887, at left. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  19. 63. View of the French lot, looking southeast, with the ...

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

    63. View of the French lot, looking southeast, with the summit of Mount Ascutney (elevation 3150 ft.) on the distant horizon at left. The meadow is flanked by a historic plantation of Norway spruce (Picea abies), dated 1887, at right; and a plantation of European larch (Larix decidua), also dated 1887, at left. - Marsh-Billings-Rockefeller National Historical Park, 54 Elm Street, Woodstock, Windsor County, VT

  20. Volume and weight characteristics of a typical Douglas-fir/ western larch stand, Coram Experimental Forest, Montana

    Treesearch

    Robert E. Benson; Joyce A. Schlieter

    1980-01-01

    An over-mature Douglas-fir/western larch stand on the Coram Experimental Forest in Montana averaged about 7,300 ft3/acre (511 rn3/ha) of wood over 3 inches (7.62 cm) in diameter, and an additional 57 tons/acre (128/ha) of fine material, before harvest. After logging, using three different cutting methods and four different levels of utilization, wood residues ranged...

  1. Role of adventitious roots in water relations of tamarack (Larix laricina) seedlings exposed to flooding.

    PubMed

    Calvo-Polanco, Mónica; Señorans, Jorge; Zwiazek, Janusz J

    2012-06-27

    Flooding reduces supply of oxygen to the roots affecting plant water uptake. Some flooding-tolerant tree species including tamarack (Larix laricina (Du Roi) K. Koch) produce adventitious roots in response to flooding. These roots were reported to have higher hydraulic conductivity under flooding conditions compared with non-adventitious roots. In the present study, we examined structural and functional modifications in adventitious roots of tamarack seedlings to explain their flooding tolerance. Seedlings were subjected to the flooding treatment for six months, which resulted in an almost complete disintegration of the existing root system and its replacement with adventitious roots. We compared gas exchange parameters and water relations of flooded plants with the plants growing in well-drained soil and examined the root structures and root water transport properties. Although flooded seedlings had lower needle chlorophyll concentrations, their stomatal conductance, net photosynthesis rates and shoot water potentials were similar to non-flooded plants, indicative of flooding tolerance. Flooded adventitious roots had higher activation energy and a higher ratio of apoplastic to cell-to-cell water flow compared with non-flooded control roots as determined with the 1-hydroxypirene 3,6,8-trisulfonic acid apoplastic tracer dye. The adventitious roots in flooded plants also exhibited retarded xylem and endodermal development and accumulated numerous starch grains in the cortex. Microscopic examination of root sections treated with the PIP1 and PIP2 antibodies revealed high immunoreactivity in the cortex of non-flooded roots, as compared with flooded roots. Structural modifications of adventitious roots suggest increased contribution of apoplastic bypass to water flow. The reduced dependence of roots on the hypoxia-sensitive aquaporin-mediated water transport is likely among the main mechanisms allowing tamarack seedlings to maintain water balance and gas exchange under

  2. [Carbon and nitrogen storages and allocation in tree layers of Fraxinus mandshurica and Larix gmelinii plantations].

    PubMed

    Mei, Li; Zhang, Zhuo-Wen; Gu, Jia-Cun; Quan, Xian-Kui; Yang, Li-Jun; Huang, Dong

    2009-08-01

    By the methods of wood analysis and sequential soil core, the biomass and productivity of the tree layers in 20-year old Fraxiuns mandshurica and Larix gmelinii plantations, as well as the carbon (C) and nitrogen (N) storages in the above- and below-ground organs of the stands, were estimated. The biomass of F. mandshurica and L. gmelinii was 6815.10 g x m(-2) and 9295.95 g x m(-2), in which, stem occupied 57.32% and 58.01%, and fine roots occupied 2.67% and 1.80%, respectively. The annual productivity of F. mandshurica and L. gmelinii was 1618.16 and 2102.45 g x m(-2) x a(-1), in which, stem accounted for 39.34% and 46.70%, and fine roots accounted for 12.06% and 5.25%, respectively. The C content in the organs of F. mandshurica was lower than that of L. gmelinii, while the N content was in adverse. The C storage of F. mandshurica was lower than that of L. gmelinii, while the N storage had no significant difference between the two tree species. The biomass, productivity, and C and N storages of aboveground organs were lower for F. mandshurica than for L. gmelinii, indicating the higher construction efficiency of the aboveground part of L. gmelinii. Due to the significant differences in the C and N contents between tree species and between the organs of same tree species, the measurement should be made on different tree species and different organs to have an accurate estimation of forest C and N storages.

  3. Hydraulic properties and fine root mass of Larix sibirica along forest edge-interior gradients

    NASA Astrophysics Data System (ADS)

    Chenlemuge, Tselmeg; Dulamsuren, Choimaa; Hertel, Dietrich; Schuldt, Bernhard; Leuschner, Christoph; Hauck, Markus

    2015-02-01

    At its southernmost distribution limit in Inner Asia, the boreal forest disintegrates into forest fragments on moist sites (e.g. north-facing slopes), which are embedded in grasslands. This landscape mosaic is characterized by a much higher forest edge-to-interior ratio than in closed boreal forests. Earlier work in the forest-steppe ecotone of Mongolia has shown that Larix sibirica trees at forest edges grow faster than in the forest interior, as the more xeric environment at the edge promotes self-thinning and edges are preferentially targeted by selective logging and livestock grazing. Lowered stand density reduces competition for water in these semi-arid forests, where productivity is usually limited by summer drought. We studied how branch and coarse root hydraulic architecture and xylem conductivity, fine root biomass and necromass, and fine root morphology of L. sibirica respond to sites differing in water availability. Studying forest edge-interior gradients in two regions of western Mongolia, we found a significant reduction of branch theoretical (Kp) and empirical conductivity (Ks) in the putatively more drought-affected forest interior in the Mongolian Altai (mean precipitation: 120 mm yr-1), while no branch xylem modification occurred in the moister Khangai Mountains (215 mm yr-1). Kp and Ks were several times larger in roots than in branches, but root hydraulics were not influenced by stand density or mean annual precipitation. Very low fine root biomass: necromass ratios at all sites, and in the forest interior in particular, suggest that L. sibirica seeks to maintain a relatively high root conductivity by producing large conduits, which results in high root mortality due to embolism during drought. Our results suggest that L. sibirica is adapted to the semi-arid climate at its southernmost distribution limit by considerable plasticity of the branch hydraulic system and a small but apparently dynamic fine root system.

  4. Role of adventitious roots in water relations of tamarack (Larix laricina) seedlings exposed to flooding

    PubMed Central

    2012-01-01

    Background Flooding reduces supply of oxygen to the roots affecting plant water uptake. Some flooding-tolerant tree species including tamarack (Larix laricina (Du Roi) K. Koch) produce adventitious roots in response to flooding. These roots were reported to have higher hydraulic conductivity under flooding conditions compared with non-adventitious roots. In the present study, we examined structural and functional modifications in adventitious roots of tamarack seedlings to explain their flooding tolerance. Results Seedlings were subjected to the flooding treatment for six months, which resulted in an almost complete disintegration of the existing root system and its replacement with adventitious roots. We compared gas exchange parameters and water relations of flooded plants with the plants growing in well-drained soil and examined the root structures and root water transport properties. Although flooded seedlings had lower needle chlorophyll concentrations, their stomatal conductance, net photosynthesis rates and shoot water potentials were similar to non-flooded plants, indicative of flooding tolerance. Flooded adventitious roots had higher activation energy and a higher ratio of apoplastic to cell-to-cell water flow compared with non-flooded control roots as determined with the 1-hydroxypirene 3,6,8-trisulfonic acid apoplastic tracer dye. The adventitious roots in flooded plants also exhibited retarded xylem and endodermal development and accumulated numerous starch grains in the cortex. Microscopic examination of root sections treated with the PIP1 and PIP2 antibodies revealed high immunoreactivity in the cortex of non-flooded roots, as compared with flooded roots. Conclusions Structural modifications of adventitious roots suggest increased contribution of apoplastic bypass to water flow. The reduced dependence of roots on the hypoxia-sensitive aquaporin-mediated water transport is likely among the main mechanisms allowing tamarack seedlings to maintain water

  5. Diurnal and seasonal change in stem respiration of Larix principis-rupprechtii trees, northern China.

    PubMed

    Yang, Yan; Zhao, Miao; Xu, Xiangtao; Sun, Zhenzhong; Yin, Guodong; Piao, Shilong

    2014-01-01

    Stem respiration is a critical and uncertain component of ecosystem carbon cycle. Few studies reported diurnal change in stem respiration as well as its linkage with climate. In this study, we investigated the diurnal and seasonal change in stem respiration and its linkage with environmental factors, in larch plantations of northern China from 2010 to 2012. The stem respiration per unit surface area (RS) showed clear diurnal cycles, ranging from 1.65±0.10 to 2.69±0.15 µmol m(-2) s(-1), increased after 6∶00, peaked at 15∶00 and then decreased. Both stem temperature and air temperature show similar diurnal pattern, while the diurnal pattern of air relative humidity is just the opposite to Rs. Similar to the diurnal cycles, seasonal change in RS followed the pattern of stem temperature. RS increased from May (1.28±0.07 µmol m(-2) s(-1)) when the stem temperature was relatively low and peaked in July (3.02±0.10 µmol m(-2) s(-1)) when the stem temperature was also the highest. Further regression analyses show that RS exponentially increases with increasing temperature, and the Q10 of Rs at mid daytime (1.97±0.17 at 12∶00 and 1.96±0.10 at 15∶00) is significantly lower than that of mid nighttime (2.60±0.14 at 00∶00 and 2.71±0.25 at 03∶00) Q10. This result not only implies that Rs is more sensitive to night than day warming, but also highlights that temperature responses of Rs estimated by only daytime measurement can lead to underestimated stem respiration increase under global warming, especially considering that temperature increase is faster during nighttime.

  6. Diurnal and Seasonal Change in Stem Respiration of Larix principis-rupprechtii Trees, Northern China

    PubMed Central

    Yang, Yan; Zhao, Miao; Xu, Xiangtao; Sun, Zhenzhong; Yin, Guodong; Piao, Shilong

    2014-01-01

    Stem respiration is a critical and uncertain component of ecosystem carbon cycle. Few studies reported diurnal change in stem respiration as well as its linkage with climate. In this study, we investigated the diurnal and seasonal change in stem respiration and its linkage with environmental factors, in larch plantations of northern China from 2010 to 2012. The stem respiration per unit surface area (RS) showed clear diurnal cycles, ranging from 1.65±0.10 to 2.69±0.15 µmol m−2 s−1, increased after 6∶00, peaked at 15∶00 and then decreased. Both stem temperature and air temperature show similar diurnal pattern, while the diurnal pattern of air relative humidity is just the opposite to Rs. Similar to the diurnal cycles, seasonal change in RS followed the pattern of stem temperature. RS increased from May (1.28±0.07 µmol m−2 s−1) when the stem temperature was relatively low and peaked in July (3.02±0.10 µmol m−2 s−1) when the stem temperature was also the highest. Further regression analyses show that RS exponentially increases with increasing temperature, and the Q10 of Rs at mid daytime (1.97±0.17 at 12∶00 and 1.96±0.10 at 15∶00) is significantly lower than that of mid nighttime (2.60±0.14 at 00∶00 and 2.71±0.25 at 03∶00) Q10. This result not only implies that Rs is more sensitive to night than day warming, but also highlights that temperature responses of Rs estimated by only daytime measurement can lead to underestimated stem respiration increase under global warming, especially considering that temperature increase is faster during nighttime. PMID:24586668

  7. Fire Effects on Microbial Enzyme Activities in Larch Forests of the Siberian Arctic

    NASA Astrophysics Data System (ADS)

    Ludwig, S.; Alexander, H. D.; Bulygina, E. B.; Mann, P. J.; Natali, S.

    2012-12-01

    Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Increased fire activity will also influence the microenvironment experienced by soil microbes in disturbed soils. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After, 1 and 8 d post-fire, we measured soil organic layer depth, soil organic matter (SOM) content, soil moisture, and CO2 flux from the plots. Additionally, we leached soils and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, soluble reactive phosphorus (SRP), and chromophoric dissolved organic matter (CDOM). Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). One day post-fire, LAP activity was similarly low in all treatments, but by 8 d post-fire, LAP activity was lower in burned plots compared to control plots, likely due to increased nitrogen content with increasing burn severity. Phosphatase activity decreased with burn severity 1 d post-fire, but after 8 d, moderate and severe burn plots exhibited increased phosphatase activity. Coupled with trends in LAP activity, this suggests a switch in nutrient limitation from N to phosphorus that is more pronounced with burn severity. β-glucosidase activity similarly decreased with burn

  8. Impacts of fire on greenhouse gas emissions in larch forest stands in northeast Siberia

    NASA Astrophysics Data System (ADS)

    Kuhn, M. A.; Schade, J. D.; Alexander, H. D.; Natali, S.

    2016-12-01

    Fire severity and frequency in boreal regions underlain by permafrost have increased over the last few decades leading to amplified permafrost thaw, land slumping, and organic matter combustion. While most boreal forests are considered sinks for methane (CH4), little research has been done to determine how fire may alter methane fluxes in these systems. The goal of our research was to examine how CH4 emissions vary along a fire severity gradient in Siberian larch forests underlain by permafrost. In July 2016 we measured physical and chemical parameters and emissions of CH4 and CO2 in terrestrial and aquatic ecosystems in high severity, low severity, and unburned larch stands in a lowland region along the Kolyma River in Northeast Siberia. Results show significantly lower pH, conductivity, and dissolved oxygen from ponds in the unburned stand. While the ponds in the low-severity and high-severity stands had similar conductivity and pH, the low-severity ponds showed higher concentrations of dissolved oxygen. Interestingly, the rates of CH4 emissions from ponds in the unburned stand (mean = 120 mg C m-2 d-1) were 2-3x higher than from the high severity stand (mean = 45 mg C m-2 d-1) and two orders of magnitude higher than the low severity ponds (mean = 1 mg C m-2 d-1). We hypothesize that carbon content and water depth may be responsible for the observed differences. The unburned ponds were significantly shallower than the other stands, which may allow a quicker path for CH4 to reach the surface without oxidizing. Results also show higher carbon content in the soils underlying the unburned ponds. Additionally, high algal biomass in the ponds in the low-severity stand may be responsible for the increased dissolved oxygen concentrations and extremely low CH4 fluxes. Understanding how boreal forest fires affect the fate of soil carbon in northern permafrost regions is critical to our overall understanding of global climate change. These results suggest that not all

  9. Fire effects on methane emissions from a larch forest in Northeastern Siberia

    NASA Astrophysics Data System (ADS)

    Kuhn, M. A.; Schade, J. D.; Natali, S.; Spawn, S.

    2015-12-01

    Understanding how boreal forest fires affect the fate of soil carbon in northern permafrost regions is critical to our understanding of feedbacks from Arctic ecosystems on global climate change. The frequency and intensity of fires have been increasing across the northern boreal and tundra region. Fire makes permafrost vulnerable because it removes the insulating plant and organic layers. The removal of these insulating layers in Siberian larch forests underlain by ice and carbon rich permafrost can lead to ground subsidence and saturate soils. Saturated and anoxic soils are ideal conditions for the production of methane, which is ~30x more effective at trapping heat than carbon dioxide. Most boreal ecosystems are currently considered to be sinks for methane, but not much research has been done to study how fire may affect methane production in these regions. We predict that fires will increase methane production in boreal ecosystems underlain by permafrost due to increases in thaw depth, ice wedge thawing, and ground subsidence. This study focused on a ten-year old burn site composed of mainly larch trees and tussocks located near the bank of the Kolyma River in Northeastern Siberia. The ground of the burn site was substantially more subsided and had larger areas of surface water and saturated soils than the nearby unburned forest. We investigated the flux of methane from the surfaces of small ponds that formed over thawing ice wedges and in the subsided depressions. While previous studies have reported low dissolved organic carbon concentrations in streams affected by fire in permafrost regions, we found high DOC concentrations in pond water (21-27 mg/L). Methane fluxes from ice wedge ponds ranged from 20 to 180 mg CH4 m-2 d-1. These values are comparable to fluxes from other permafrost ecosystems including bogs, wet tundra, and fens that are considered globally significant sources of CH4. Additionally, the burned forest contained some subsided areas that were

  10. Species presence frequency and diversity in different patch types along an altitudinal gradient: Larix chinensis Beissn in Qinling Mountains (China).

    PubMed

    Huang, Minyi; Duan, Renyan; Wang, Shixiong; Wang, Zhigao; Fan, Weiyi

    2016-01-01

    Forest communities are mosaic systems composed of patches classified into four different developmental patch types: gap patch (G), building patch (B), mature patch (M) and degenerate patch (D). To study the mechanisms maintaining diversity in subalpine coniferous forests, species presence frequency and diversity in the four distinct patch types (G, B, M and D) of Larix chinensis conifer forests at three altitudinal gradients in the Qinling Mountains were analyzed. Our results were as follows: (1) Different species (or functional groups) had distinct presence frequencies in the four different patch types along the altitudinal gradient; (2) Some species or functional groups (species groups sharing similar traits and responses to the environment) only occurred in some specific patches. For seed dispersal, species using wind mainly occurred in G and D, while species using small animals mainly occurred in B and M; (3) Species composition of adjacent patch types was more similar than non-adjacent patch types, based on the lower β diversity index of the former; (4) The maximum numbers of species and two diversity indices (D' and H') were found in the middle altitudes. Various gap-forming processes and dispersal limitation may be the two major mechanisms determining species diversity in Larix chinensis coniferous forests at the patch scale.

  11. Estimation of wood stiffness and strength properties of hybrid larch by near-infrared spectroscopy.

    PubMed

    Fujimoto, Takaaki; Yamamoto, Hiroyuki; Tsuchikawa, Satoru

    2007-08-01

    This work was undertaken to investigate the feasibility of near-infrared (NIR) spectroscopy for estimating wood mechanical properties, i.e., modulus of elasticity (MOE) and modulus of rupture (MOR) in bending tests. Two sample sets having large and limited density variation were prepared to examine the effects of wood density on estimation of MOE and MOR by the NIR technique. Partial least squares (PLS) analysis was employed and it was found that the relationships between laboratory-measured and NIR-predicted values were good in the case of sample sets having large density variation. MOE could be estimated even when density variation in the sample set was limited. It was concluded that absorption bands due to the OH group in the semi-crystalline or crystalline regions of cellulose strongly influenced the calibrations for bending stiffness of hybrid larch. This was also suggested from the result that both alpha-cellulose content and cellulose crystallinity showed moderate positive correlation to wood stiffness.

  12. Temporal and Spatial Wildfire Dynamics of Northern Siberia: Larch Forests and Insect Outbreak Areas

    NASA Astrophysics Data System (ADS)

    Kharuk, Viacheslav; Antamoshkina, Olga; Ponomarev, Eugene

    2017-04-01

    Wildfire number and burned area temporal dynamics within all of Siberia and along a south-north transect in central Siberia (45 - 73°N) were studied based on NOAA/AVHRR and Terra/MODIS data and field measurements for the period since 1996. In addition, fire return interval along the south-north transect was analyzed. Third, pest outbreak (Siberian silkmoth) impact on the wildfires was studied. Both, number of forest fires and burned area in Siberia increased during recent decades. Significant correlations were found between forest fires, burned areas and air temperature (r = 0.5) and drought index (SPEI) (r = -0.43). Within larch stands along the transect wildfire frequency was strongly correlated with incoming solar radiation (r = 0.91). Fire danger period length decreased linearly from south to north along the transect. Fire return interval increased from 80 years at 62°N to 200 years at the Arctic Circle (66°33'N), and to about 300 years near the northern limit of closed forest stands ( 71+°N). That increase was negatively correlated with incoming solar radiation (r = -0.95). Siberian silkmoth outbreaks leads to an order of magnitude increase in burned area and fire frequency. Multiple fires turns former "dark needle conifer" taiga into grass and bush communities for decades.

  13. A Laser Photoacoustic Analysis of Residual CO2 and H2O in Larch Stems

    PubMed Central

    Ageev, Boris; Ponomarev, Yurii; Sapozhnikova, Valeria; Savchuk, Dmitry

    2014-01-01

    Every so often, the results obtained from investigations into the effects of varying environmental conditions on the tree growth rate at the same sites and on the change in the carbon balance in plants, using traditional methods, are found to differ widely. We believe that the reason for the ambiguity of the data has to do with failure to account for the role of the residual CO2 (and H2O) in the tree wood exhibiting a climate response. In our earlier work, the results of a laser photoacoustic gas analysis of CO2 and H2O vacuum-desorbed from disc tree rings of evergreen conifer trees were presented. In this paper, laser photoacoustic measurements of tree ring gases in deciduous conifer trees and CO2 carbon isotope composition determined by means of a mass spectrometer are given. Conclusions are made regarding the response of annual larch CO2 disc tree ring distributions to climatic parameters (temperatures and precipitation). The data about the CO2 disc content for different sites are compared. PMID:25808838

  14. Geographic variation, genetic structure and conservation unit designation in the larch mountain salamander( Plethodon larselli)

    USGS Publications Warehouse

    Wagner, R.S.; Miller, Mark P.; Crisafulli, Charles; Haig, Susan M.

    2005-01-01

    The Larch Mountain salamander (Plethodon larselli Burns, 1954) is an endemic species in the Pacific northwestern United States facing threats related to habitat destruction. To facilitate development of conservation strategies, we used DNA sequences and RAPDs (random amplified polymorphic DNA) to examine differences among populations of this species. Phylogenetic analyses of cytochrome b revealed a clade of haplotypes from populations north of the Columbia River derived from a clade containing haplotypes from the river's southwestern region. Haplotypes from southeastern populations formed a separate clade. Nucleotide diversity was reduced in northern populations relative to southern populations. These results were corroborated by analyses of RAPD loci, which revealed similar patterns of clustering and diversity. Network analyses suggested that northern populations were colonized following a range expansion mediated by individuals from populations located southwest of the river. Changes in the Columbia River's location during the Pliocene and Pleistocene likely released distributional constraints on this species, permitting their northern range expansion. Based on the barrier presented by the Columbia River's present location and differences in haplotype diversity and population structure observed between northern and southern populations, we suggest that designation of separate management units encompassing each region may assist with mitigating different threats to this species.

  15. Ozone risk assessment for an Alpine larch forest in two vegetative seasons with different approaches: comparison of POD1 and AOT40.

    PubMed

    Finco, Angelo; Marzuoli, Riccardo; Chiesa, Maria; Gerosa, Giacomo

    2017-06-12

    The upper vegetation belts like larch forests are supposed to be under great pressure because of climate change in the next decades. For this reason, the evaluation of the risks due to abiotic stressors like ozone is a key step. Two different approaches were used here: mapping AOT40 index by means of passive samplers and direct measurements of ozone deposition.Measurements of ozone fluxes using the eddy-correlation technique were carried out for the first time over a larch forest in Paspardo (I) at 1750 m a.s.l. Two field campaigns were run: the first one in 2010 from July to October and the second one in the following year from June to September. Vertical exchange of ozone, energy, and momentum were measured on a tower platform at 26 m above ground level to study fluxes dynamics over this ecosystem. Since the tower was located on a gentle slope, an "ad hoc" methodology was developed to minimize the effects of the terrain inclination. The larch forest uptake was estimated by means of a two-layer model to separate the understorey uptake from the larch one. Even if the total ozone fluxes were generally high, up to 30-40 nmol O3 m(-2) s(-1) in both years, the stomatal uptake by the larch forest was relatively low (around 15% of the total deposition).Ozone risk was assessed considering the POD1 received by the larch forest and the exposure index AOT40 estimated with both local data and data from the map obtained by the passive samplers monitoring.

  16. Tree Growth and Competition in a Betula platyphylla–Larix cajanderi Post-fire Forest in Central Kamchatka

    PubMed Central

    DOLEŽAL, JIŘÍ; ISHII, HIROAKI; VETROVA, VALENTINA P.; SUMIDA, AKIHIRO; HARA, TOSHIHIKO

    2004-01-01

    • Background and Aims Fire is the dominant disturbance in central Kamchatka boreal forests, yet patterns and mechanisms of stand recovery have not been investigated. • Methods Measurements were made of 1433 stems ≥1·3 m height and annual radial increments of 225 randomly selected trees in a 0·4-ha plot of a 53-year-old fire-origin mixed-species stand to examine the spatio-temporal variation in establishment, growth, size inequality and the mode of competition among individual trees. Growth variations were related to tree size, age and local interference with neighbours. • Key Results Betula platyphylla formed the main canopy following a fire in 1947, with Larix cajanderi and Pinus pumila progressively reinvading the lower tree and shrub stratum. Most B. platyphylla originated from sprouts in small patches (polycormons) during the first 15 post-fire years. Betula platyphylla had normal distributions of diameter and age classes, but negatively skewed height distribution, as expected from shade-intolerant, pioneer species. Larix cajanderi had fewer tall and many short individuals. The smaller and younger B. platyphylla grew disproportionately more in diameter than larger trees from 1950 to 1975, and hence stem size inequalities decreased. The reverse trend was observed from 1995 to 2000: larger trees grew more, indicating an increasing asymmetry of competition for light. Betula platyphylla had steady diameter growth in the first 25 post-fire years, after which the growth declined in smaller trees. Neighbourhood analysis showed that the decline resulted from increased competition from taller neighbours. • Conclusions The observed growth patterns suggest that mode of interactions altered during stand development from early stages of weak competition for soil resources released by fire to later stages of asymmetric competition for light. Asymmetric crown competition started later than reported in other studies, which can be attributed to the lower stem

  17. Tree growth and competition in a Betula platyphylla-Larix cajanderi post-fire forest in central Kamchatka.

    PubMed

    Dolezal, Jirí; Ishii, Hiroaki; Vetrova, Valentina P; Sumida, Akihiro; Hara, Toshihiko

    2004-09-01

    Fire is the dominant disturbance in central Kamchatka boreal forests, yet patterns and mechanisms of stand recovery have not been investigated. Measurements were made of 1433 stems > or =1.3 m height and annual radial increments of 225 randomly selected trees in a 0.4-ha plot of a 53-year-old fire-origin mixed-species stand to examine the spatio-temporal variation in establishment, growth, size inequality and the mode of competition among individual trees. Growth variations were related to tree size, age and local interference with neighbours. Betula platyphylla formed the main canopy following a fire in 1947, with Larix cajanderi and Pinus pumila progressively reinvading the lower tree and shrub stratum. Most B. platyphylla originated from sprouts in small patches (polycormons) during the first 15 post-fire years. Betula platyphylla had normal distributions of diameter and age classes, but negatively skewed height distribution, as expected from shade-intolerant, pioneer species. Larix cajanderi had fewer tall and many short individuals. The smaller and younger B. platyphylla grew disproportionately more in diameter than larger trees from 1950 to 1975, and hence stem size inequalities decreased. The reverse trend was observed from 1995 to 2000: larger trees grew more, indicating an increasing asymmetry of competition for light. Betula platyphylla had steady diameter growth in the first 25 post-fire years, after which the growth declined in smaller trees. Neighbourhood analysis showed that the decline resulted from increased competition from taller neighbours. The observed growth patterns suggest that mode of interactions altered during stand development from early stages of weak competition for soil resources released by fire to later stages of asymmetric competition for light. Asymmetric crown competition started later than reported in other studies, which can be attributed to the lower stem density leaving much space for individual growth, greater relative

  18. Biosynthesis of the microtubule-destabilizing diterpene pseudolaric acid B from golden larch involves an unusual diterpene synthase

    PubMed Central

    Mafu, Sibongile; Karunanithi, Prema Sambandaswami; Palazzo, Teresa Ann; Harrod, Bronwyn Lee; Rodriguez, Selina Marakana; Mollhoff, Iris Natalie; O’Brien, Terrence Edward; Tong, Shen; Fiehn, Oliver; Tantillo, Dean J.; Bohlmann, Jörg; Zerbe, Philipp

    2017-01-01

    The diversity of small molecules formed via plant diterpene metabolism offers a rich source of known and potentially new biopharmaceuticals. Among these, the microtubule-destabilizing activity of pseudolaric acid B (PAB) holds promise for new anticancer agents. PAB is found, perhaps uniquely, in the coniferous tree golden larch (Pseudolarix amabilis, Pxa). Here we describe the discovery and mechanistic analysis of golden larch terpene synthase 8 (PxaTPS8), an unusual diterpene synthase (diTPS) that catalyzes the first committed step in PAB biosynthesis. Mining of the golden larch root transcriptome revealed a large TPS family, including the monofunctional class I diTPS PxaTPS8, which converts geranylgeranyl diphosphate into a previously unknown 5,7-fused bicyclic diterpene, coined “pseudolaratriene.” Combined NMR and quantum chemical analysis verified the structure of pseudolaratriene, and co-occurrence with PxaTPS8 and PAB in P. amabilis tissues supports the intermediacy of pseudolaratriene in PAB metabolism. Although PxaTPS8 adopts the typical three-domain structure of diTPSs, sequence phylogeny places the enzyme with two-domain TPSs of mono- and sesqui-terpene biosynthesis. Site-directed mutagenesis of PxaTPS8 revealed several catalytic residues that, together with quantum chemical calculations, suggested a substantial divergence of PxaTPS8 from other TPSs leading to a distinct carbocation-driven reaction mechanism en route to the 5,7-trans-fused bicyclic pseudolaratriene scaffold. PxaTPS8 expression in microbial and plant hosts provided proof of concept for metabolic engineering of pseudolaratriene. PMID:28096378

  19. Climate-Induced Landsliding within the Larch Dominant Permafrost Zone of Central Siberia

    NASA Technical Reports Server (NTRS)

    Kharuk, Viacheslav I.; Shushpanov, Alexandr S.; Im, Sergei T.; Ranson, Kenneth J.

    2016-01-01

    Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62 000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and Gravity Recovery and Climate Experiment satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with t (max) > 0 deg C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

  20. Climate-induced landsliding within the larch dominant permafrost zone of central Siberia

    NASA Astrophysics Data System (ADS)

    Kharuk, Viacheslav I.; Shushpanov, Alexandr S.; Im, Sergei T.; Ranson, Kenneth J.

    2016-04-01

    Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62 000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and Gravity Recovery and Climate Experiment satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with t max > 0 °C r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

  1. Free radical generation in Pinus sylvestris and Larix decidua seeds primed with polyethylene glycol or potassium salt solutions.

    PubMed

    Naglreiter, Christina; Reichenauer, Thomas G; Goodman, Bernard A; Bolhàr-Nordenkampf, Harald R

    2005-02-01

    Electron paramagnetic resonance (EPR) spectra of Pinus sylvestris and Larix decidua seeds show that priming with PEG+200 mg kg(-1) gibberelic acid (GA(3)) results in appreciably higher free radical contents than in unprimed control samples. Only relatively minor changes in the free radical levels were observed in seeds primed with K(+) salts. However, both priming treatments have been reported previously to result in faster germination rates compared to controls without changing the germination percentage. In measurements on individual seeds of L. decidua, there were no significant differences between the mean free radical levels in viable and non-viable seeds within each treatment group. Thus, the elevation in free radical levels in the PEG+GA(3) treatments appear to be a direct consequence of the priming treatment and do not correspond to the initiation of germination.

  2. Flowering on long and short shoots of Larix laricina in response to differential timing of GA(4/7) applications.

    PubMed

    Eysteinsson, Throstur; Greenwood, Michael S.

    1995-01-01

    In Larix, reproductive buds most often occur terminally on short shoots, but they can also differentiate in lateral positions on long shoots. The phenology of long and short shoots differs considerably, with short shoots breaking bud and expanding about 5 weeks before the start of long shoot extension. Foliar sprays of GA(4/7) were applied to 160 branches on 10 greenhouse-grown Larix laricina (Du Roi) K. Koch grafts either before (early) of after (late) the start of long shoot extension, or during both periods, to test whether the timing of GA(4/7) application affects flowering on short and long shoots. All three treatments induced flowering on both long and short shoots. The early GA(4/7) treatment led to slightly, but not significantly, more flowering on short shoots than on long shoots, whereas the late GA(4/7) treatment resulted in increased flowering on both types of shoots, but primarily on long shoots. Application of GA(4/7) during both periods did not result in increased flowering over the early or late treatment alone. Based on the fact that gibberellins are metabolized rapidly in conifers and our finding that GA(4/7) applied before shoot elongation, when the bud primordia were at a very early stage of development (detectable bud differentiation only occurred several weeks later), induced flowering on long shoots, we conclude that the early GA(4/7) treatment did not affect differentiation as it was occurring, but somehow predisposed the bud primordia to differentiate reproductively.

  3. [Time lag effects of throughfall in natural Larix gmelinii forest in the north of Great Xing'an Mountains, China].

    PubMed

    Liu, Yu-jie; Man, Xiu-ling; Sheng, Hong-cai

    2015-11-01

    Based on a natural Larix gmelinii forest from Mohe Ecological Station, located in north of Great Xing' an Mountains, time lag effects of throughfall inside the Larix gmelinii forest were analyzed by measuring rainfall, throughfall and stemflow with the method of location observation. The result showed that forest throughfall, stemflow and canopy interception accounted for 76.5%, 2.6% and 20.9% of total rainfall, respectively. Time lag of rainfall inside L. gmelinii forest was found both in beginning and termination of rainfall compared to outside, and the higher the rainfall level, the shorter the time lag of throughfall. For throughfall and stemflow, variations of time lag were (67.8 ± 7.8)--(17.2 ± 3.9) min and (112.0 ± 38.8)--(48.3 ± 10.6) min, respectively. The time lag of throughfall decreased with the increasing rainfall intensity under the same rainfall level. When the rainfall intensity was greater than 2 mm · h(-1), the time lag of throughfall was shortened significantly, but it increased with prolonging the antecedent dry period before rainfall. Rainfall would be the critical factor to affect the time lag of throughfall when the antecedent dry period was longer than 48 h. Termination of throughfall also lagged when rainfall termination happened with a rainfall greater than 5.0 mm. The time lag of throughfall termination increased with increasing the rainfall intensity, but it had no significant relationship with the antecedent dry period before rainfall. However, the termination of stemflow occurred prior to rainfall, which was relevant to the rainfall level, and the smaller the rainfall level, the sooner the stemflow terminated.

  4. Variation in lateral shoot elongation patterns and hybrid vigor in full-sib families and interspecific hybrids of larch.

    PubMed

    Baltunis, Brian S.; Greenwood, Michael S.

    1999-02-01

    Time of shoot initiation and cessation, and rate and duration of lateral shoot elongation of full-sib families of Larix decidua Mill., L. laricina (Du Roi) C. Koch, and interspecific hybrids between L. decidua and L. kaempferi (Lamb.) Carrière, L. kaempferi x decidua, L. laricina x decidua, and L. laricina x kaempferi were explored in relation to hybrid vigor determined by height growth after 5 years. Height growth of L. laricina and L. decidua families was significantly less than height growth of the interspecific hybrids. Differences were observed for all lateral shoot elongation traits among L. laricina, L. decidua, and the interspecific hybrids. Lateral shoots of L. laricina families were the first to both initiate and cease elongation, and grew for the shortest period of time. Overall, the length of the shoot elongation period and date of cessation of shoot growth were significantly correlated with total height growth after 5 years, but the time of shoot initiation was not. Rate of elongation of lateral shoots was strongly correlated with growth increment in 1996, but was weakly correlated with total height growth after 5 years. Hybrid vigor in Larix seems to be partly a function of late cessation or increased duration of shoot elongation, or both.

  5. Interannual and seasonal variations in energy and carbon exchanges over the larch forests on the permafrost in northeastern Mongolia

    NASA Astrophysics Data System (ADS)

    Miyazaki, Shin; Ishikawa, Mamoru; Baatarbileg, Nachin; Damdinsuren, Sodov; Ariuntuya, Nymsambuu; Jambaljav, Yamkhin

    2014-06-01

    The larch forests on the permafrost in northeastern Mongolia are located at the southern limit of the Siberian taiga forest, which is one of the key regions for evaluating climate change effects and responses of the forest to climate change. We conducted long-term monitoring of seasonal and interannual variations in hydrometeorological elements, energy, and carbon exchange in a larch forest (48°15‧24‧‧N, 106°51‧3‧‧E, altitude: 1338 m) in northeastern Mongolia from 2010 to 2012. The annual air temperature and precipitation ranged from -0.13 °C to -1.2 °C and from 230 mm to 317 mm. The permafrost was found at a depth of 3 m. The dominant component of the energy budget was the sensible heat flux (H) from October to May (H/available energy [Ra] = 0.46; latent heat flux [LE]/Ra = 0.15), while it was the LE from June to September (H/Ra = 0.28, LE/Ra = 0.52). The annual net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (RE) were -131 to -257 gC m-2 y-1, 681-703 gC m-2 y-1, and 423-571 gC m-2 y-1, respectively. There was a remarkable response of LE and NEE to both vapor pressure deficit and surface soil water content.

  6. Effects of climate and fire on short-term vegetation recovery in the boreal larch forests of Northeastern China

    NASA Astrophysics Data System (ADS)

    Liu, Zhihua

    2016-11-01

    Understanding the influence of climate variability and fire characteristics in shaping postfire vegetation recovery will help to predict future ecosystem trajectories in boreal forests. In this study, I asked: (1) which remotely-sensed vegetation index (VI) is a good proxy for vegetation recovery? and (2) what are the relative influences of climate and fire in controlling postfire vegetation recovery in a Siberian larch forest, a globally important but poorly understood ecosystem type? Analysis showed that the shortwave infrared (SWIR) VI is a good indicator of postfire vegetation recovery in boreal larch forests. A boosted regression tree analysis showed that postfire recovery was collectively controlled by processes that controlled seed availability, as well as by site conditions and climate variability. Fire severity and its spatial variability played a dominant role in determining vegetation recovery, indicating seed availability as the primary mechanism affecting postfire forest resilience. Environmental and immediate postfire climatic conditions appear to be less important, but interact strongly with fire severity to influence postfire recovery. If future warming and fire regimes manifest as expected in this region, seed limitation and climate-induced regeneration failure will become more prevalent and severe, which may cause forests to shift to alternative stable states.

  7. Effects of climate and fire on short-term vegetation recovery in the boreal larch forests of Northeastern China.

    PubMed

    Liu, Zhihua

    2016-11-18

    Understanding the influence of climate variability and fire characteristics in shaping postfire vegetation recovery will help to predict future ecosystem trajectories in boreal forests. In this study, I asked: (1) which remotely-sensed vegetation index (VI) is a good proxy for vegetation recovery? and (2) what are the relative influences of climate and fire in controlling postfire vegetation recovery in a Siberian larch forest, a globally important but poorly understood ecosystem type? Analysis showed that the shortwave infrared (SWIR) VI is a good indicator of postfire vegetation recovery in boreal larch forests. A boosted regression tree analysis showed that postfire recovery was collectively controlled by processes that controlled seed availability, as well as by site conditions and climate variability. Fire severity and its spatial variability played a dominant role in determining vegetation recovery, indicating seed availability as the primary mechanism affecting postfire forest resilience. Environmental and immediate postfire climatic conditions appear to be less important, but interact strongly with fire severity to influence postfire recovery. If future warming and fire regimes manifest as expected in this region, seed limitation and climate-induced regeneration failure will become more prevalent and severe, which may cause forests to shift to alternative stable states.

  8. Effects of climate and fire on short-term vegetation recovery in the boreal larch forests of Northeastern China

    PubMed Central

    Liu, Zhihua

    2016-01-01

    Understanding the influence of climate variability and fire characteristics in shaping postfire vegetation recovery will help to predict future ecosystem trajectories in boreal forests. In this study, I asked: (1) which remotely-sensed vegetation index (VI) is a good proxy for vegetation recovery? and (2) what are the relative influences of climate and fire in controlling postfire vegetation recovery in a Siberian larch forest, a globally important but poorly understood ecosystem type? Analysis showed that the shortwave infrared (SWIR) VI is a good indicator of postfire vegetation recovery in boreal larch forests. A boosted regression tree analysis showed that postfire recovery was collectively controlled by processes that controlled seed availability, as well as by site conditions and climate variability. Fire severity and its spatial variability played a dominant role in determining vegetation recovery, indicating seed availability as the primary mechanism affecting postfire forest resilience. Environmental and immediate postfire climatic conditions appear to be less important, but interact strongly with fire severity to influence postfire recovery. If future warming and fire regimes manifest as expected in this region, seed limitation and climate-induced regeneration failure will become more prevalent and severe, which may cause forests to shift to alternative stable states. PMID:27857204

  9. Importance of soil moisture and N availability to larch growth and distribution in the Arctic taiga-tundra boundary ecosystem, northeastern Siberia

    NASA Astrophysics Data System (ADS)

    Liang, Maochang; Sugimoto, Atsuko; Tei, Shunsuke; Bragin, Ivan V.; Takano, Shinya; Morozumi, Tomoki; Shingubara, Ryo; Maximov, Trofim C.; Kiyashko, Serguei I.; Velivetskaya, Tatiana A.; Ignatiev, Alexander V.

    2014-12-01

    To better understand the factors controlling the growth of larch trees in Arctic taiga-tundra boundary ecosystem, we conducted field measurements of photosynthesis, tree size, nitrogen (N) content, and isotopic ratios in larch needles and soil. In addition, we observed various environmental parameters, including topography and soil moisture at four sites in the Indigirka River Basin, near Chokurdakh, northeastern Siberia. Most living larch trees grow on mounds with relatively high elevations and dry soils, indicating intolerance of high soil moisture. We found that needle δ13C was positively correlated with needle N content and needle mass, and these parameters showed spatial patterns similar to that of tree size. These results indicate that trees with high needle N content achieved higher rates of photosynthesis, which resulted in larger amounts of C assimilation and larger C allocation to needles and led to larger tree size than trees with lower needle N content. A positive correlation was also found between needle N content and soil NH 4 + pool. Thus, soil inorganic N pool may indicate N availability, which is reflected in the needle N content of the larch trees. Microtopography plays a principal role in N availability, through a change in soil moisture. Relatively dryer soil of mounds with higher elevation and larger extent causes higher rates of soil N production, leading to increased N availability for plants, in addition to larger rooting space for trees to uptake more N.

  10. A collaborative fire hazard reduction/ecosystem restoration stewardship project in a Montana mixed ponderosa pine/Douglas-fir/western larch wildland urban interface

    Treesearch

    Steve Slaughter; Laura Ward; Michael Hillis; Jim Chew; Rebecca McFarlan

    2004-01-01

    Forest Service managers and researchers designed and evaluated alternative disturbance-based fire hazard reduction/ecosystem restoration treatments in a greatly altered low-elevation ponderosa pine/Douglas-fir/western larch wildland urban interface. Collaboratively planned improvement cutting and prescribed fire treatment alternatives were evaluated in simulations of...

  11. The role of organic soil layer on the fate of Siberian larch forest and near-surface permafrost under changing climate: A simulation study

    NASA Astrophysics Data System (ADS)

    SATO, H.; Iwahana, G.; Ohta, T.

    2013-12-01

    Siberian larch forest is the largest coniferous forest region in the world. In this vast region, larch often forms nearly pure stands, regenerated by recurrent fire. This region is characterized by a short and dry growing season; the annual mean precipitation for Yakutsk was only about 240 mm. To maintain forest ecosystem under such small precipitation, underlying permafrost and seasonal soil freezing-thawing-cycle have been supposed to play important roles; (1) frozen ground inhibits percolation of soil water into deep soil layers, and (2) excess soil water at the end of growing season can be carried over until the next growing season as ice, and larch trees can use the melt water. As a proof for this explanation, geographical distribution of Siberian larch region highly coincides with continuous and discontinuous permafrost zone. Recent observations and simulation studies suggests that existences of larch forest and permafrost in subsurface layer are co-dependent; permafrost maintains the larch forest by enhancing water use efficiency of trees, while larch forest maintains permafrost by inhibiting solar radiation and preventing heat exchanges between soil and atmosphere. Owing to such complexity and absence of enough ecosystem data available, current-generation Earth System Models significantly diverse in their prediction of structure and key ecosystem functions in Siberian larch forest under changing climate. Such uncertainty should in turn expand uncertainty over predictions of climate, because Siberian larch forest should have major role in the global carbon balance with its huge area and vast potential carbon pool within the biomass and soil, and changes in boreal forest albedo can have a considerable effect on Northern Hemisphere climate. In this study, we developed an integrated ecosystem model, which treats interactions between plant-dynamics and freeze-thaw cycles. This integrated model contains a dynamic global vegetation model SEIB-DGVM, which simulates

  12. [Spatial Heterogeneity of Soil Respiration in a Planted Larch Forest in Shanxi Plateau].

    PubMed

    Yan, Jun-xia; Li, Hong-jian; Li, Jun-jian; Wu, Jiang-xing

    2015-05-01

    Based on the data from a planted larch forest in Panquangou Natural Reserve of Shanxi Province, at three sampling scales (4, 2, and 1 m, respectively), soil respiration (Rs) and its affecting factors including soil temperature at 5 cm (T5), 10 cm (T10), and 15 cm (T15) depths, soil water content (Ws), litter mass (Lw), litter moisture (Lm), soil total carbon (C), and soil total nitrogen ( N) were determined. The spatial heterogeneities of Rs and the environmental factors were further analyzed and their intrinsic correlations were established. The results of traditional statistics showed that the spatial variations of Rs and the all measured factors were in the middle range; Rs were highly significantly positively correlated with T10, T15, and N (P < 0.01); significantly positively correlated with Lm (P < 0.05); highly significantly negatively correlated with C/N ratio (P < 0.01); and not significantly correlated with T5, Ws, Lw and C (P > 0.05). Multiple stepwise regression analysis indicated that the four factors of Lm, T10, N, and Ws together accounted for 36% of Rs heterogeneity. The results of geo-statistical analysis demonstrated that Rs was in a medium spatial autocorrelation; random and structural factors accounted for 39.5% and 60.5% of Rs heterogeneity, respectively. And the factors such as climate, landform, and soil played a leading role. The results also illustrated that the ranges for soil factors were different and the range for both Rs and T10 was 25 meters. The fractal dimension of the soil index was in the following order: Lw and C/N ratio (1.95) > N (1.91) > C (1.89) > Rs (1.78) > Lm (1.77 ) > Ws (1.69) > T10 (1.42). The spatial distribution of Rs was in consistent agreement with those of T10, Lm, C, and N; but different with those of Ws and C/N ratio. With a fixed cofidence level and certain estimated accuracy, the required sampling number of each item differed, corresponding to its spatial variation degree.

  13. Key mechanisms of metabolic changes in mountain pine and larch under drought in the Swiss National Park

    NASA Astrophysics Data System (ADS)

    Churakova, Olga; Bigler, Christof; Bryukhanova, Marina; Siegwolf, Rolf

    2014-05-01

    Forests are of great ecological, economic and social importance worldwide. In many regions they have been recently affected by water deficits during summer droughts due to increasing temperatures and shortage of precipitation (Allen et al. 2010). Climate models predict that drought frequency will continue to increase during the 21st century and beyond (CH 2011). Since the foundation of the Swiss National Park (SNP) in 1914 these forests have not been managed any more, which allows to study natural processes in these forest ecosystems. Since the 1990s, annual and spring temperatures increased in the SNP up to 0.5 ºC and 1.02 ºC, respectively, and average summer temperature increased up to 0.6 ºC. Annual precipitation decreased by 81 mm compared to the mean values (927 mm) from 1917 to 1989. Therefore, detailed studies of drought effects on the physiological functioning of trees over the last decades are needed. Recently, mortality processes of mountain pines were observed in the Swiss National Park (Bigler, Rigling 2013). It is of great interest to investigate and compare the physiological responses of mountain pine and larch to drought and to understand the mechanisms behind the mortality processes. The goal of our study is to investigate the key mechanisms of tree physiological responses to drought in the SNP using state-of-the-art methods of classical dendrochronology, tree physiology, stable isotope, and compound-specific isotope analyses. Long-term responses of mountain pine and larch trees from north- and south-facing sites to drought will be inferred from tree-ring width data. Based on climatic data a drought index will be calculated and reconstructed back in time. New chronologies for stable carbon and oxygen isotope ratios derived from both pine and larch tree-ring cellulose will provide retrospective insight into the long-term whole-plant physiological control of gas exchange derived from estimates of stomatal conductance, photosynthetic rate and

  14. Soils of postpyrogenic larch stands in Central Siberia: Morphology, physicochemical properties, and specificity of soil organic matter

    NASA Astrophysics Data System (ADS)

    Startsev, V. V.; Dymov, A. A.; Prokushkin, A. S.

    2017-08-01

    Morphological features, physicochemical properties, and specific characteristics of the organic matter of cryozems (Cryosols) under postpyrogenic larch forests affected by fires 2, 6, 22, 55, and 116 years ago are considered. The morphological changes in the soils affected by fires are manifested by the burning of the upper organic horizons with preservation of pyrogenic features in the soils for more than a century after the fire. In the first years (2 and 6 years) after the fire, the acidity of the organic horizons and their base saturation become lower. The postpyrogenic soils are characterized by the smaller contribution of the organic horizons to the total pools of soil organic carbon. In the studied cryozems, the organic carbon content is correlated with the contents of oxalate-extractable iron and aluminum. A decrease in the content of water-soluble organic compounds in the soils is observed after the fires; gradually, their content increases upon restoration of the ground cover.

  15. Diversity and community structure of ectomycorrhizal fungi associated with Larix chinensis across the alpine treeline ecotone of Taibai Mountain.

    PubMed

    Han, Qisheng; Huang, Jian; Long, Dongfeng; Wang, Xiaobing; Liu, Jianjun

    2017-03-09

    Alpine treeline ecotones represent ecosystems that are vulnerable to climate change. We investigated the ectomycorrhizal (ECM) community, which has potential to stabilize alpine ecosystems. ECM communities associated with Larix chinensis were studied in four zones along a natural ecotone from a mixed forest stand over pure forest stands, the timberline, and eventually, the treeline (3050-3450 m) in Tabai Mountain, China. Sixty operational taxonomic units (OTUs) of ECM fungi were identified by sequencing the rDNA internal transcribed spacer of ECM tips. The richness of ECM species increased with elevation. The soil C/N ratio was the most important factor explaining ECM species richness. The treeline zone harbored some unique ECM fungi whereas no unique genera were observed in the timberline and pure forest zone. Elevation and topography were equally important factors influencing ECM communities in the alpine region. We suggest that a higher diversity of the ECM fungal community associated with L. chinensis in the treeline zone could result from niche differentiation.

  16. Long-term measurement of terpenoid flux above a Larix kaempferi forest using a relaxed eddy accumulation method

    NASA Astrophysics Data System (ADS)

    Mochizuki, Tomoki; Tani, Akira; Takahashi, Yoshiyuki; Saigusa, Nobuko; Ueyama, Masahito

    2014-02-01

    Terpenoids emitted from forests contribute to the formation of secondary organic aerosols and affect the carbon budgets of forest ecosystems. To investigate seasonal variation in terpenoid flux involved in the aerosol formation and carbon budget, we measured the terpenoid flux of a Larix kaempferi forest between May 2011 and May 2012 by using a relaxed eddy accumulation method. Isoprene was emitted from a fern plant species Dryopteris crassirhizoma on the forest floor and monoterpenes from the L. kaempferi. α-Pinene was the dominant compound, but seasonal variation of the monoterpene composition was observed. High isoprene and monoterpene fluxes were observed in July and August. The total monoterpene flux was dependent on temperature, but several unusual high positive fluxes were observed after rain fall events. We found a good correlation between total monoterpene flux and volumetric soil water content (r = 0.88), and used this correlation to estimate monoterpene flux after rain events and calculate annual terpenoid emissions. Annual carbon emission in the form of total monoterpenes plus isoprene was determined to be 0.93% of the net ecosystem exchange. If we do not consider the effect of rain fall, carbon emissions may be underestimated by about 50%. Our results suggest that moisture conditions in the forest soil is a key factor controlling the monoterpene emissions from the forest ecosystem.

  17. Physiological responses of three deciduous conifers (Metasequoia glyptostroboides, Taxodium distichum and Larix laricina) to continuous light: adaptive implications for the early Tertiary polar summer.

    PubMed

    Equiza, M Alejandra; Day, Michael E; Jagels, Richard

    2006-03-01

    Polar regions were covered with extensive forests during the Cretaceous and early Tertiary, and supported trees comparable in size and productivity to those of present-day temperate forests. With a winter of total or near darkness and a summer of continuous, low-angle illumination, these temperate, high-latitude forests were characterized by a light regime without a contemporary counterpart. Although maximum irradiances were much lower than at mid-latitudes, the 24-h photoperiod provided similar integrated light flux. Taxodium, Larix and Metasequoia, three genera of deciduous conifers that occurred in paleoarctic wet forests, have extant, closely related descendents. However, the contemporary relative abundance of these genera differs greatly from that in the paleoarctic. To provide insight into attributes that favor competitive success in a continuous-light environment, we subjected saplings of these genera to a natural photoperiod or a 24-h photoperiod and measured gas exchange, chlorophyll fluorescence, non-structural carbohydrate concentrations, biomass production and carbon allocation. Exposure to continuous light significantly decreased photosynthetic capacity and quantum efficiency of photosystem II in Taxodium and Larix, but had minimal influence in Metasequoia. In midsummer, foliar starch concentration substantially increased in both Taxodium and Larix saplings grown in continuous light, which may have contributed to end-product down-regulation of photosynthetic capacity. In contrast, Metasequoia allocated photosynthate to continuous production of new foliar biomass. This difference in carbon allocation may have provided Metasequoia with a two fold advantage in the paleoarctic by minimizing depression of photosynthetic capacity and increasing photosynthetic surface.

  18. [Effects of controlled-release fertilizer and organic amendment on the construction of nutrients reserves in Larix olgensis container seedlings].

    PubMed

    Wei, Hong-xu; Xu, Cheng-yang; Ma, Lü-yi; Jiang, Li-ni

    2011-07-01

    A 2 x 2 factorial experiment was conducted to study the effect of fertilization on Larix olgensis container seedlings. 36.36 or 18.18 mg controlled-release fertilizer (CRF) N and 0 or 1.82 g FM organic amendment (OA) per seedling were applied. There were no significant responses to fertilization in the seedling height, collar diameter, biomass, and potassium (K) uptake. Applying FM OA increased the number of first-order lateral roots with a length > 1 cm (P = 0.040), the tap root length (TRL) (P = 0.012), and the ratio of TRL to seedling height (P = 0.008). Comparing with low application rate CRF N, high application rate CRF N increased the N concentration in root (P = 0.035) as well as the N reserves in stem (P = 0.005), root (P = 0.037), and stem plus root (P = 0.030), and the P reserves in stem (P = 0.047). Applying 36.36 mg CRF N plus 1.82 g FM OA increased the N concentrations in leaf and in stem plus root by 137% (P = 0.040) and 21% (P = 0.013), respectively, and the N reserves in stem (P = 0.020), root (P = 0.017), and stem plus root (P = 0.013). Vector analysis revealed that high application rate of CRF N led to the excess of seedlings N and P, while applying FM OA alleviated the N and P deficiency but led to the K depletion. For nursing L. olgensis container seedlings, a solution of CRF 18 mg N combined with 1.82 g FM OA per seedling was recommended.

  19. [Temporal variation of soil greenhouse gases fluxes in a cold-temperate Larix gmelinii forest in Inner Mongolia, China].

    PubMed

    Ma, Xiu-Zhi; Zhang, Qiu-Liang; Li, Chang-Sheng; Chen, Gao-Wa; Wang, Fei

    2012-08-01

    By using static chamber-gas chromatograph technique, an in situ measurement was conducted on the soil CH4, CO2, and N2O fluxes in a cold-temperate Larix gmelinii forest in Inner Mongolia from June to September 2007, aimed to understand the diurnal and seasonal variations of soil greenhouse gasses fluxes and their relations with the associated environmental factors in L. gmelinii forests in cold-temperate zone. In growth season, the soil in the L. gmelinii forest was the sink of atmospheric CH4, with the flux ranged from 22.3 to 107.8 microg CH4-C x m(-2) x h(-1). The mean monthly uptake of CH4 in June, July, August, and September was 34.0 +/- 7.1, 71.4 +/- 9.4, 86.3 +/- 7.9, and 40.7 +/- 6.2 microg x m(-2) x h(-1), respectively. The mean diurnal flux of soil CH4 from June to September showed the same variation trend, i. e., peaked at 10:00 am. The diurnal variation of soil CO2 flux showed an obvious double-peak, and the mean monthly CO2 flux was in the order of July > August > June > September. Soil N2O flux varied dramatically from -9.1 to 31.7 microg x m(-2) x h(-1). Soil temperature and humidity were the main factors affecting the CH4 and CO2 fluxes, and soil temperature mainly affected the N2O flux. In the L. gmelinii forest, the CH4, CO2, and N2O fluxes measured at 10:00 am could represent the diurnal CH4, CO2, and N2O fluxes on the same day.

  20. [Parameter sensitivity of simulating net primary productivity of Larix olgensis forest based on BIOME-BGC model].

    PubMed

    He, Li-hong; Wang, Hai-yan; Lei, Xiang-dong

    2016-02-01

    Model based on vegetation ecophysiological process contains many parameters, and reasonable parameter values will greatly improve simulation ability. Sensitivity analysis, as an important method to screen out the sensitive parameters, can comprehensively analyze how model parameters affect the simulation results. In this paper, we conducted parameter sensitivity analysis of BIOME-BGC model with a case study of simulating net primary productivity (NPP) of Larix olgensis forest in Wangqing, Jilin Province. First, with the contrastive analysis between field measurement data and the simulation results, we tested the BIOME-BGC model' s capability of simulating the NPP of L. olgensis forest. Then, Morris and EFAST sensitivity methods were used to screen the sensitive parameters that had strong influence on NPP. On this basis, we also quantitatively estimated the sensitivity of the screened parameters, and calculated the global, the first-order and the second-order sensitivity indices. The results showed that the BIOME-BGC model could well simulate the NPP of L. olgensis forest in the sample plot. The Morris sensitivity method provided a reliable parameter sensitivity analysis result under the condition of a relatively small sample size. The EFAST sensitivity method could quantitatively measure the impact of simulation result of a single parameter as well as the interaction between the parameters in BIOME-BGC model. The influential sensitive parameters for L. olgensis forest NPP were new stem carbon to new leaf carbon allocation and leaf carbon to nitrogen ratio, the effect of their interaction was significantly greater than the other parameter' teraction effect.

  1. [Complexity and its integrative effects of the time lags of environment factors affecting Larix gmelinii stem sap flow].

    PubMed

    Wang, Hui-Mei; Sun, Wei; Zu, Yuan-Gang; Wang, Wen-Jie

    2011-12-01

    Based on the one-year (2005) observations with a frequency of half hour on the stem sap flow of Larix gmelinii plantation trees planted in 1969 and the related environmental factors air humidity (RH), air temperature (T(air)), photosynthetic components active radiation (PAR), soil temperature (T(soil)), and soil moisture (TDR), principal analysis (PCA) and correction analysis were made on the time lag effect of the stem flow in different seasons (26 days of each season) and in a year via dislocation analysis, with the complexity and its integrative effects of the time lags of environment factors affecting the stem sap flow approached. The results showed that in different seasons and for different environmental factors, the time lag effect varied obviously. In general, the time lag of PAR was 0.5-1 hour ahead of sap flow, that of T(air) and RH was 0-2 hours ahead of or behind the sap flow, and the time lags of T(soil) and TDR were much longer or sometimes undetectable. Because of the complexity of the time lags, no evident improvements were observed in the linear correlations (R2, slope, and intercept) when the time lags based on short-term (20 days) data were used to correct the time lags based on whole year data. However, obvious improvements were found in the standardized and non-standardized correlation coefficients in stepwise multiple regressions, i.e., the time lag corrections could improve the effects of RH, but decreased the effects of PAR, T(air), and T(soil). PCA could be used to simplify the complexity. The first and the second principal components could stand for over 75% information of all the environmental factors in different seasons and in whole year. The time lags of both the first and the second principal components were 1-1.5 hours in advance of the sap flow, except in winter (no time lag effect).

  2. Ultrasound-Assisted Extraction of Arabinogalactan and Dihydroquercetin Simultaneously from Larix gmelinii as a Pretreatment for Pulping and Papermaking

    PubMed Central

    Ma, Chunhui; Yang, Lei; Li, Wei; Yue, Jinquan; Li, Jian; Zu, Yuangang

    2014-01-01

    An ultrasound-assisted extraction (UAE) method using ethanol was applied for extracting arabinogalactan (AG) and dihydroquercetin (DHQ) simultaneously from larch wood, as a pretreatment for pulping and papermaking. The extraction parameters were optimized by a Box-Behnken experimental design with the yields of AG and DHQ as the response values. Under optimum conditions (three extractions, each using 40% ethanol, for 50 min, 200 W ultrasound power and 1∶18 solid-liquid ratio), the yields of AG and DHQ were 183.4 and 36.76 mg/g, respectively. After UAE pretreated, the wood chips were used for Kraft pulping (KP) and high boiling solvent pulping (HBSP). The pulping yield after pretreatment was higher than that of untreated (the pulping yields of untreated HBSP and KP were 42.37% and 39.60%, and the pulping yields of HBSP and KP after UAE-pretreated were 44.23% and 41.50% respectively), as indicated by a lower kappa number (77.91 and 27.30 for untreated HBSP and KP; 77.01 and 26.83 for UAE-pretreated HBSP and KP). Furthermore, the characteristics of paper produced from pretreated wood chips were superior to those from the untreated chips: the basis weight was lower (85.67 and 82.48 g·cm−2 for paper from untreated KP and HBSP; 79.94 and 80.25 g·cm−2 for paper from UAE-pretreated KP and HBSP), and the tensile strengths, tearing strengths, bursting strengths, and folding strengths were higher than these of paper after UAE-pretreated, respectively. PMID:25460911

  3. Factors promoting larch dominance in central Siberia: fire versus growth performance and implications for carbon dynamics at the boundary of evergreen and deciduous conifers

    NASA Astrophysics Data System (ADS)

    Schulze, E.-D.; Wirth, C.; Mollicone, D.; von Lüpke, N.; Ziegler, W.; Achard, F.; Mund, M.; Prokushkin, A.; Scherbina, S.

    2012-04-01

    The relative role of fire and of climate in determining canopy species composition and aboveground carbon stocks were investigated. Measurements were made along a transect extending from the dark taiga zone of central Siberia, where Picea and Abies dominate the canopy, into the Larix zone of eastern Siberia. We test the hypotheses that the change in canopy species composition is based (1) on climate-driven performance only, (2) on fire only, or (3) on fire-performance interactions. We show that the evergreen conifers Picea obovata and Abies sibirica are the natural late-successional species both in central and eastern Siberia, provided there has been no fire for an extended period of time. There are no changes in performance of the observed species along the transect. Fire appears to be the main factor explaining the dominance of Larix and of soil carbon. Of lesser influence were longitude as a proxy for climate, local hydrology and active-layer thickness. We can only partially explain fire return frequency, which is not only related to climate and land cover, but also to human behavior. Stand-replacing fires decreased from 300 to 50 yrs between the Yenisei Ridge and the upper Tunguska. Repeated non-stand-replacing surface fires eliminated the regeneration of Abies and Picea. With every 100 yrs since the last fire, the percentage of Larix decreased by 20%. Biomass of stems of single trees did not show signs of age-related decline. Relative diameter increment was 0.41 ± 0.20% at breast height and stem volume increased linearly over time with a rate of about 0.36 t C ha-1 yr-1 independent of age class and species. Stand biomass reached about 130 t C ha-1(equivalent to about 520 m3 ha-1). Individual trees of Larix were older than 600 yrs. The maximum age and biomass seemed to be limited by fungal rot of heart wood. 60% of old Larix and Picea and 30% of Pinus sibirica trees were affected by stem rot. Implications for the future role of fire and of plant diseases are

  4. Fire Effects on Microbial Dynamics and C, N, and P Cycling in Larch Forests of the Siberian Arctic

    NASA Astrophysics Data System (ADS)

    Ludwig, S.; Alexander, H. D.; Mann, P. J.; Natali, S.; Schade, J. D.

    2013-12-01

    Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After 1 day, 8 days and 1 year post-fire, we measured CO2 flux from the plots, and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, PO4, and chromophoric dissolved organic matter (CDOM) from soil leachates. Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). Both 1 day and 8 days post-fire DOC, TDN, NH4, and PO4 all increased with burn severity, but by 1 year they were similar to control plots. The aromaticity and molecular weight of DOM decreased with fire severity. One day post-fire we observed a spike in phenol oxidase activity in the severe burns only, and a decline in β-glucosidase and phosphatase activity. By 8 days post-fire all enzyme activities were at the level of the control plots. 1 year post-fire LAP, β-glucosidase, and phosphatase all decreased with fire severity, parallel to a decrease in CO2 flux by fire severity. Ratios of enzymatic activity 1 year post-fire reflect a switch of resource allocation from P acquiring to N acquiring activities in more severe fires. Our results show an immediate microbial response to the short-term effects

  5. [Prediction models for ground surface fuels moisture content of Larix gmelinii stand in Daxing'anling of China based on one-hour time step].

    PubMed

    Yu, Hong-Zhou; Sen, Jin; Di, Xue-Ying

    2013-06-01

    By using the equilibrium moisture content-time lag methods of Nelson and Simard and the meteorological element regression method, this paper studied the dynamics of the moisture content of ground surface fine dead fuels under a Larix gmelinii stand on the sunny slope in Daxing' anling with a time interval of one hour, established the corresponding prediction models, and analyzed the prediction errors under different understory densities. The results showed that the prediction methods of the fuels moisture content based on one-hour time step were applicable for the typical Larix gmelinii stand in Daxing' anling. The mean absolute error and the mean relative error of Simard method was 1.1% and 8.5%, respectively, being lower than those of Nelson method and meteorological element regression method, and close to those of similar studies. On the same slopes and slope positions, the fuel moisture content varied with different understory densities, and thus, it would be necessary to select the appropriate equilibrium moisture content model for specific regional stand and position, or establish the fuel moisture content model based on specific stand when the dynamics of fuel moisture content would be investigated with a time interval of one hour.

  6. A multi-taxon approach reveals the effect of management intensity on biodiversity in Alpine larch grasslands.

    PubMed

    Nascimbene, Juri; Fontana, Veronika; Spitale, Daniel

    2014-07-15

    In the Alps, larch grasslands form one of the most pleasing aspects of the landscape. However, their effectiveness in contributing to biodiversity conservation may depend on the intensity of their management. We used a multi-taxon approach to evaluate the effects of the intensification of management practices and those of abandonment on the biodiversity of the main autotrophic organisms hosted in this habitat, including vascular plants, bryophytes, and lichens. The study was carried out in the eastern part of South Tyrol, in the Italian Alps, where the diversity patterns of these three organismal groups were compared among intensively managed, extensively managed, and abandoned stands. The management intensity was found to strongly influence the biodiversity of the organisms, with a general pattern indicating the best conditions in extensively managed stands. Both abandonment and management intensification were detrimental to biodiversity through different mechanisms that led to species loss or to major shifts in species composition. However, the most negative effects were related to management intensification, mainly due to the high nitrogen supply, providing evidence for the increasing impact of eutrophication on Alpine environments.

  7. De novo characterization of Larix gmelinii (Rupr.) Rupr. transcriptome and analysis of its gene expression induced by jasmonates.

    PubMed

    Men, Lina; Yan, Shanchun; Liu, Guanjun

    2013-08-13

    Larix gmelinii is a dominant tree species in China's boreal forests and plays an important role in the coniferous ecosystem. It is also one of the most economically important tree species in the Chinese timber industry due to excellent water resistance and anti-corrosion of its wood products. Unfortunately, in Northeast China, L. gmelinii often suffers from serious attacks by diseases and insects. The application of exogenous volatile semiochemicals may induce and enhance its resistance against insect or disease attacks; however, little is known regarding the genes and molecular mechanisms related to induced resistance. We performed de novo sequencing and assembly of the L. gmelinii transcriptome using a short read sequencing technology (Illumina). Chemical defenses of L. gmelinii seedlings were induced with jasmonic acid (JA) or methyl jasmonate (MeJA) for 6 hours. Transcriptomes were compared between seedlings induced by JA, MeJA and untreated controls using a tag-based digital gene expression profiling system. In a single run, 25,977,782 short reads were produced and 51,157 unigenes were obtained with a mean length of 517 nt. We sequenced 3 digital gene expression libraries and generated between 3.5 and 5.9 million raw tags, and obtained 52,040 reliable reference genes after removing redundancy. The expression of disease/insect-resistance genes (e.g., phenylalanine ammonialyase, coumarate 3-hydroxylase, lipoxygenase, allene oxide synthase and allene oxide cyclase) was up-regulated. The expression profiles of some abundant genes under different elicitor treatment were studied by using real-time qRT-PCR.The results showed that the expression levels of disease/insect-resistance genes in the seedling samples induced by JA and MeJA were higher than those in the control group. The seedlings induced with MeJA elicited the strongest increases in disease/insect-resistance genes. Both JA and MeJA induced seedlings of L. gmelinii showed significantly increased expression

  8. Mitigation of Drought Limitation in Photosynthesis of Larix gmelinii Saplings by Clear-cutting in East-Siberian Taiga

    NASA Astrophysics Data System (ADS)

    Saito, H.; Suzuki, M.; Iijima, H.; Onoe, T.; Yamamuro, K.; Maximov, T. C.; Takahashi, K.

    2002-12-01

    Although Larix gmelinii forest ecosystem on permafrost is frequently disturbed by human activity like logging, regeneration system is not developed because of little understanding of the eco-physiological process. In the east-Siberian ecosystem, water cycle plays an important role in the regeneration, namely the annual precipitation is only 200-250mm approximately, and the melting of permafrost after the logging changes forest to wet land called as Alas where regeneration of tree is impossible. Thus we focus the drought stress in CO2 assimilation rate in the regenerated L. gmelinii sapling under canopy, and the effects of clear-cutting. In order to evaluate the drought limitation in the CO2 assimilation rate, in this study, irrigation treatment was conduced for 10 days in understory and clear-cut area. The clear-cutting was carried out in 2000, and this experiment was carried out in 2002. The light saturated CO2 assimilation rate (Amax) was measured in the morning and the afternoon. Volumetric soil moisture content at the 15 cm of the depth was approximately 10% under canopy and 30% in clear-cut area. The midday depression of Amax was larger in understory than that in clear-cut area, especially the understoried Amax was near 0 μmol m-2 s-1. During the irrigation treatment, i.e. 10 days, the volumetric soil moisture content was kept over 30% in the both areas. After the irrigation, the Amax increased to 3.2-fold in understoried and 1.3-fold in clear-cut area in morning. The Amax in afternoon increased to 50-fold in understory and 2.5-fold in clear-cut area after the irrigation. Thus the drought limitation of Amax was larger in understory than clear-cutting area. These results suggest that (1) drought stress is major factor to limit the CO2 assimilation of the regenerated L. gmelinii saplings under canopy, and (2) clear-cutting mitigates the drought limitation in the CO2 assimilation rate during the early stage of the disturbance of clear-cutting.

  9. Adipogenic constituents from the bark of Larix laricina du Roi (K. Koch; Pinaceae), an important medicinal plant used traditionally by the Cree of Eeyou Istchee (Quebec, Canada) for the treatment of type 2 diabetes symptoms.

    PubMed

    Shang, Nan; Guerrero-Analco, José A; Musallam, Lina; Saleem, Ammar; Muhammad, Asim; Walshe-Roussel, Brendan; Cuerrier, Alain; Arnason, John T; Haddad, Pierre S

    2012-06-14

    Diabetes is a growing epidemic worldwide, especially among indigenous populations. Larix laricina was identified through an ethnobotanical survey as a traditional medicine used by Healers and Elders of the Cree of Eeyou Istchee of northern Quebec to treat symptoms of diabetes and subsequent in vitro screening confirmed its potential. We used a bioassay-guided fractionation approach to isolate the active principles responsible for the adipogenic activity of the organic extract (80% EtOH) of the bark of Larix laricina. Post-confluent 3T3-L1 cells were differentiated in the presence or absence of the crude extract, fractions or isolates of Larix laricina for 7 days, then triglycerides content was measured using AdipoRed reagent. We identified a new cycloartane triterpene (compound 1), which strongly enhanced adipogenesis in 3T3-L1 cells with an EC(50) of 7.7 μM. It is responsible for two thirds of the activity of the active fraction of Larix laricina. The structure of compound 1 was established on the basis of spectroscopic methods (IR, HREIMS, 1D and 2D NMR) as 23-oxo-3α-hydroxycycloart-24-en-26-oic acid. We also identified several known compounds, including three labdane-type diterpenes (compounds 2-4), two tetrahydrofuran-type lignans (compounds 5-6), three stilbenes (compounds 7-9), and taxifolin (compound 10). Compound 2 (13-epitorulosol) also potentiated adipogenesis (EC(50) 8.2 μM) and this is the first report of a biological activity for this compound. This is the first report of putative antidiabetic principles isolated from Larix laricina, therefore increasing the interest in medicinal plants from the Cree pharmacopeia. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Can climate variations be inferred from tree-ring parameters and stable isotopes from Larix decidua? Juvenile effects, budmoth outbreaks, and divergence issue

    NASA Astrophysics Data System (ADS)

    Daux, V.; Edouard, J. L.; Masson-Delmotte, V.; Stievenard, M.; Hoffmann, G.; Pierre, M.; Mestre, O.; Danis, P. A.; Guibal, F.

    2011-09-01

    Larch wood has been used for centuries as a building material. Hence, the study of the tree-ring width, the latewood maximal density, and the oxygen and carbon isotope composition of the cellulose of this tree provides potential and valuable insights when reconstructing past climate variability. We explore the qualities and limitations of these proxies, focusing on a forest standing the Névache valley (French Alps). The analysis of 15 trees demonstrates a small intra-tree variability in comparison with the inter-tree variability of δ 13C and δ 18O, and shows that 6 trees, at least, must be pooled to make a population-representative sample. Our results show no juvenile effect for δ 13C. Unlike tree-ring width and density, δ 13C and δ 18O are not altered by budmouth outbreaks. These two parameters therefore appear well suited for climate reconstructions, and depict a strong correlation with July-August temperature and relative humidity. The δ 18O of larch cellulose is also strongly linked with the previous winter (December-March) oxygen isotopic composition of the precipitation. This is consistent with a winter water recharge of soil and ground. The past variations of July-August maximum temperature and relative humidity were established using two different combinations of the isotopic ratios. Uncertainties on the reconstructions are estimated respectively at ± 1.4 °C and 3.6%. Inter-annual variations of temperature and relative humidity are well reproduced. However, the reconstructed July-August temperature series diverges from the instrumental one, being lower, after ca. 1990. The effects of the variation through time of the depth of source water and of the ecophysiological response of trees to rising CO 2 on the isotope composition are discussed as possible causes of divergence. This 'divergence problem' strongly questions the possibility of producing appropriate isotope-based temperature calibration.The relationships between isotopes and the July

  11. Biogeochemistry of stable Ca and radiogenic Sr isotopes in a larch-covered permafrost-dominated watershed of Central Siberia

    NASA Astrophysics Data System (ADS)

    Bagard, Marie-Laure; Schmitt, Anne-Désirée; Chabaux, François; Pokrovsky, Oleg S.; Viers, Jérôme; Stille, Peter; Labolle, François; Prokushkin, Anatoly S.

    2013-08-01

    Stable Ca and radiogenic Sr isotope compositions were measured in different compartments (stream water, soil solutions, rocks, soils and soil leachates and vegetation) of a small permafrost-dominated watershed in the Central Siberian Plateau. The Sr and Ca in the area are supplied by basalt weathering and atmospheric depositions, which significantly impact the Sr isotopic compositions. Only vegetation significantly fractionates the calcium isotopes within the watershed. These fractionations occur during Ca uptake by roots and along the transpiration stream within the larch trees and are hypothesised to be the result of chromatographic processes and Ca oxalate crystallisations during Ca circulation or storage within plant organs. Biomass degradation significantly influences the Ca isotopic compositions of soil solutions and soil leachates via the release of light Ca, and organic and organo-mineral colloids are thought to affect the Ca isotopic compositions of soil solutions by preferential scavenging of 40Ca. The imprint of organic matter degradation on the δ44/40Ca of soil solutions is much more significant for the warmer south-facing slope of the watershed than for the shallow and cold soil active layer of the north-facing slope. As a result, the available stock of biomass and the decomposition rates appear to be critical parameters that regulate the impact of vegetation on the soil-water system in permafrost areas. Finally, the obtained δ44/40Ca patterns contrast with those described for permafrost-free environments with a much lower δ44/40Ca fractionation factor between soils and plants, suggesting specific features of organic matter decomposition in permafrost environments. The biologically induced Ca isotopic fractionation observed at the soil profile scale is not pronounced at the scale of the streams and large rivers in which the δ44/40Ca signature may be controlled by the heterogeneity of lithological sources.

  12. A carbon foam with a bimodal micro–mesoporous structure prepared from larch sawdust for the gas-phase toluene adsorption

    SciTech Connect

    Liu, Shouxin; Huang, Zhanhua; Wang, Rui

    2013-07-15

    Highlights: ► Network carbon foam containing a bimodal pore distribution was prepared from Larch. ► Liquefaction route was used for the preparation of morphology controllable carbon. ► Pore structure of carbon foam was controlled through KOH activation. - Abstract: A carbon foam with a bimodal micro–mesopore distribution, was prepared by submitting larch sawdust to liquefaction, resinification, foaming, carbonization and KOH activation. The morphology, pore texture and crystal microstructure was characterized by scanning and transmission electron microscopy, nitrogen adsorption analysis and X-ray powder diffraction. A honeycomb structure with adjacent cells was observed for the precursor of carbon foam. After KOH activation, the cell wall of precursor shrunk and broke. This lead to the formation of a well-connected 3D network and developed ligament pore structure (surface area of 554–1918 m{sup 2}/g) containing bimodal pores, 2.1 and 3.9 nm in diameter. The porous carbon foam prepared at 700 °C exhibited a much higher gas-phase toluene removal than commercial activated carbon fiber owing to the 3D network and bimodal pore structure.

  13. Comparative toxicity of Acephate, Diflubenzuron, and Malathion to larvae of the Larch Casebearer, Coleophora laricella (Lepidoptera: Coleophoridae) and adults of its parasites, Chrysocharis laricinellae1 and Dicladocerus nearcticus1,2

    Treesearch

    Marion Page; Roger B Ryan; Nancy Rappaport; Fred< sup> 3< /sup> Schmidt

    1982-01-01

    Fourth-instar larch casebearer, Coleophora laricella (Hübner), was significantly less susceptible to acephate and malathion than were adults of its parasites. Chrysocharis larcinellae(Ratz.) and Dicladocerus nearcticus Yoshimoto (P0.01) than the hosts to diflubenzuron. Malathion was equally...

  14. Temporal changes of soil physic-chemical properties at different soil depths during larch afforestation by multivariate analysis of covariance

    PubMed Central

    Wang, Hui-Mei; Wang, Wen-Jie; Chen, Huanfeng; Zhang, Zhonghua; Mao, Zijun; Zu, Yuan-Gang

    2014-01-01

    Soil physic-chemical properties differ at different depths; however, differences in afforestation-induced temporal changes at different soil depths are seldom reported. By examining 19 parameters, the temporal changes and their interactions with soil depth in a large chronosequence dataset (159 plots; 636 profiles; 2544 samples) of larch plantations were checked by multivariate analysis of covariance (MANCOVA). No linear temporal changes were found in 9 parameters (N, K, N:P, available forms of N, P, K and ratios of N: available N, P: available P and K: available K), while marked linear changes were found in the rest 10 parameters. Four of them showed divergent temporal changes between surface and deep soils. At surface soils, changing rates were 262.1 g·kg−1·year−1 for SOM, 438.9 mg·g−1·year−1 for C:P, 5.3 mg·g−1·year−1 for C:K, and −3.23 mg·cm−3·year−1 for bulk density, while contrary tendencies were found in deeper soils. These divergences resulted in much moderated or no changes in the overall 80-cm soil profile. The other six parameters showed significant temporal changes for overall 0–80-cm soil profile (P: −4.10 mg·kg−1·year−1; pH: −0.0061 unit·year−1; C:N: 167.1 mg·g−1·year−1; K:P: 371.5 mg·g−1 year−1; N:K: −0.242 mg·g−1·year−1; EC: 0.169 μS·cm−1·year−1), but without significant differences at different soil depths (P > 0.05). Our findings highlight the importance of deep soils in studying physic-chemical changes of soil properties, and the temporal changes occurred in both surface and deep soils should be fully considered for forest management and soil nutrient balance. PMID:24772281

  15. Temporal changes of soil physic-chemical properties at different soil depths during larch afforestation by multivariate analysis of covariance.

    PubMed

    Wang, Hui-Mei; Wang, Wen-Jie; Chen, Huanfeng; Zhang, Zhonghua; Mao, Zijun; Zu, Yuan-Gang

    2014-04-01

    Soil physic-chemical properties differ at different depths; however, differences in afforestation-induced temporal changes at different soil depths are seldom reported. By examining 19 parameters, the temporal changes and their interactions with soil depth in a large chronosequence dataset (159 plots; 636 profiles; 2544 samples) of larch plantations were checked by multivariate analysis of covariance (MANCOVA). No linear temporal changes were found in 9 parameters (N, K, N:P, available forms of N, P, K and ratios of N: available N, P: available P and K: available K), while marked linear changes were found in the rest 10 parameters. Four of them showed divergent temporal changes between surface and deep soils. At surface soils, changing rates were 262.1 g·kg(-1)·year(-1) for SOM, 438.9 mg·g(-1)·year(-1) for C:P, 5.3 mg·g(-1)·year(-1) for C:K, and -3.23 mg·cm(-3)·year(-1) for bulk density, while contrary tendencies were found in deeper soils. These divergences resulted in much moderated or no changes in the overall 80-cm soil profile. The other six parameters showed significant temporal changes for overall 0-80-cm soil profile (P: -4.10 mg·kg(-1)·year(-1); pH: -0.0061 unit·year(-1); C:N: 167.1 mg·g(-1)·year(-1); K:P: 371.5 mg·g(-1) year(-1); N:K: -0.242 mg·g(-1)·year(-1); EC: 0.169 μS·cm(-1)·year(-1)), but without significant differences at different soil depths (P > 0.05). Our findings highlight the importance of deep soils in studying physic-chemical changes of soil properties, and the temporal changes occurred in both surface and deep soils should be fully considered for forest management and soil nutrient balance.

  16. LaAP2L1, a heterosis-associated AP2/EREBP transcription factor of Larix, increases organ size and final biomass by affecting cell proliferation in Arabidopsis.

    PubMed

    Li, Ai; Zhou, Yanan; Jin, Chuan; Song, Wenqin; Chen, Chengbin; Wang, Chunguo

    2013-11-01

    In Larix and in some crops, heterosis is prevalent and has been widely used in breeding to produce excellent varieties. However, the molecular basis of heterosis in Larix remains ambiguous. LaAP2L1, a member of the AP2/EREBP transcription factor family, has been suggested to be involved in heterosis in Larix hybrids. Here, the function and regulation of LaAP2L1 were further explored. Overexpression of LaAP2L1 led to markedly enlarged organs and heterosis-like traits in Arabidopsis. Fresh weight of leaves was almost twice as great as in vector controls. Likewise, seed yield of 35S::LaAP2L1 individual plants was >200% greater than that of control plants. The enlarged organs and heterosis-like traits displayed by 35S::LaAP2L1 plants were mainly due to enhanced cell proliferation and prolonged growth duration. At the molecular level, LaAP2L1 upregulated the expression of ANT, EBP1, and CycD3;1 and inhibited the expression of ARGOS in 35S::LaAP2L1 plants, suggesting an important molecular role of LaAP2L1 in regulating plant organ development. These findings provide new insights into the formation of heterosis in woody plants and suggest that LaAP2L1 has potential applications in breeding high-yielding crops and energy plants. In addition, 50 AP2/EREBP transcription factors, including LaAP2L1, in Larix were identified by transcriptome sequencing, and phylogenetic analysis was conducted. This provided information that will be important in further revealing the functions of these transcription factors.

  17. Effect of light conditions on anatomical and biochemical aspects of somatic and zygotic embryos of hybrid larch (Larix × marschlinsii)

    PubMed Central

    von Aderkas, Patrick; Teyssier, Caroline; Charpentier, Jean-Paul; Gutmann, Markus; Pâques, Luc; Le Metté, Claire; Ader, Kevin; Label, Philippe; Kong, Lisheng; Lelu-Walter, Marie-Anne

    2015-01-01

    Background and Aims In conifers, mature somatic embryos and zygotic embryos appear to resemble one another physiologically and morphologically. However, phenotypes of cloned conifer embryos can be strongly influenced by a number of in vitro factors and in some instances clonal variation can exceed that found in nature. This study examines whether zygotic embryos that develop within light-opaque cones differ from somatic embryos developing in dark/light conditions in vitro. Embryogenesis in larch is well understood both in situ and in vitro and thus provides a suitable system for addressing this question. Methods Features of somatic and zygotic embryos of hybrid larch, Larix × marschlinsii, were quantified, including cotyledon numbers, protein concentration and phenol chemistry. Somatic embryos were placed either in light or darkness for the entire maturation period. Embryos at different developmental stages were embedded and sectioned for histological analysis. Key Results Light, and to a lesser degree abscisic acid (ABA), influenced accumulation of protein and phenolic compounds in somatic and zygotic embryos. Dark-grown mature somatic embryos had more protein (91·77 ± 11·26 µg protein mg–1 f.wt) than either dark-grown zygotic embryos (62·40 ± 5·58) or light-grown somatic embryos (58·15 ± 10·02). Zygotic embryos never accumulated phenolic compounds at any stage, whereas somatic embryos stored phenolic compounds in the embryonal root caps and suspensors. Light induced the production of quercetrin (261·13 ± 9·2 µg g–1 d.wt) in somatic embryos. Mature zygotic embryos that were removed from seeds and placed on medium in light rapidly accumulated phenolics in the embryonal root cap and hypocotyl. Delaying germination with ABA delayed phenolic compound accumulation, restricting it to the embryonal root cap. Conclusions In larch embryos, light has a negative effect on protein accumulation, but a positive effect on phenol

  18. Effects of atmospheric and climate change at the timberline of the Central European Alps

    PubMed Central

    Wieser, Gerhard; Matyssek, Rainer; Luzian, Roland; Zwerger, Peter; Pindur, Peter; Oberhuber, Walter; Gruber, Andreas

    2011-01-01

    This review considers potential effects of atmospheric change and climate warming within the timberline ecotone of the Central European Alps. After focusing on the impacts of ozone (O3) and rising atmospheric CO2 concentration, effects of climate warming on the carbon and water balance of timberline trees and forests will be outlined towards conclusions about changes in tree growth and treeline dynamics. Presently, ambient ground-level O3 concentrations do not exert crucial stress on adult conifers at the timberline of the Central European Alps. In response to elevated atmospheric CO2 Larix decidua showed growth increase, whereas no such response was found in Pinus uncinata. Overall climate warming appears as the factor responsible for the observed growth stimulation of timberline trees. Increased seedling re-establishment in the Central European Alps however, resulted from invasion into potential habitats rather than upward migration due to climate change, although seedlings will only reach tree size upon successful coupling with the atmosphere and thus loosing the beneficial microclimate of low stature vegetation. In conclusion, future climate extremes are more likely than the gradual temperature increase to control treeline dynamics in the Central European Alps. PMID:21379395

  19. Field survey of growth and colonization of nonnative trees on mainland Alaska.

    Treesearch

    John. Alden

    2006-01-01

    Six of nine nonnative boreal conifers in three genera (Abies, Larix, and Pinus) regenerated in 11 to 31 years after they were introduced to mainland Alaska. Lodgepole pine (Pinus contorta var. latifolia Engel.) and the Siberian larches (Larix sibirica Ledeb. and...

  20. Impacts of global warming on boreal larch forest in East Siberia: simulations with a coupled carbon cycle and fire regime model

    NASA Astrophysics Data System (ADS)

    Ito, A.

    2005-12-01

    Boreal forest is one of the focal areas in the study of global warming and carbon cycle. In this study, a coupled carbon cycle and fire regime model was developed and applied to a larch forest in East Siberia, near Yakutsk. Fire regime is simulated with a cellular automaton (20 km x 20 km), in which fire ignition, propagation, and extinction are parameterized in a stochastic manner, including the effects of fuel accumulation and weather condition. For each grid, carbon cycle is simulated with a 10-box scheme, in which net biome production by photosynthesis, respiration, decomposition, and biomass burning are calculated explicitly. Model parameters were calibrated with field data of biomass, litter stock, and fire statistics; the carbon cycle scheme was examined with flux measurement data. As a result, the model successfully captured average carbon stocks, productivity, fire frequency, and biomass burning. To assess the effects of global warming, a series of simulations were performed using climatic projections based on the IPCC-SRES emission scenarios from 1990 to 2100. The range of uncertainty among the different climate models and emission scenarios was assessed by using multi-model projection data by CCCma, CCSR/NIES, GFDL, and HCCPR corresponding to the SRES A2 and B2 scenarios. The model simulations showed that global warming in the 21st century would considerably enhance the fire regime (e.g., cumulative burnt area increased by 80 to 120 percent), leading to larger carbon emission by biomass burning. The effect was so strong that growth enhancement by elevated atmospheric CO2 concentration and elongated growing period was cancelled out at landscape scale. In many cases, the larch forest was estimated to act as net carbon sources of 2 to 5 kg C m_|2 by the end of the 21st century, underscoring the importance of forest fire monitoring and management in this region.

  1. Soil Properties Related to Coniferous Seedling Height Growth in Northern Wisconsin

    Treesearch

    John J. Rawinski; James A. Bowles; Nonan V. Noste

    1980-01-01

    Soil properties (organic matter content, pH, texture, and microclimate) were related to early height growth of jack pine (Pinus banksiana, Lamb.), red pine (Pinus resinosa, Ait.), white spruce (Picea glauca, (Moench) Voss), and hybrid larch (Larix leptolepis x Larizx decidua) planted in northern Wisconsin. Based on 2-year height growth, jack pine and hybrid larch...

  2. Dynamics at the treeline: differential responses of Picea mariana and Larix laricina to climate change in eastern subarctic Québec

    NASA Astrophysics Data System (ADS)

    Dufour-Tremblay, Geneviève; Lévesque, Esther; Boudreau, Stéphane

    2012-12-01

    Treelines are known to be temperature-sensitive ecotones, and therefore could rapidly expand their range limits in response to climate warming. Observations of lack of range expansion, however, indicate that ecological constraints partly control the treeline ecotones. The main objectives of this study were to evaluate Picea mariana and Larix laricina recruitment and growth at and above the altitudinal treeline of Kangiqsualujjuaq (Nunavik), where warmer temperatures since the 1990s have already triggered shrub expansion. We mapped, harvested, dated and measured tree individuals along two altitudinal gradients from the forested stands below the treeline to hilltops. Since the 1990s, a pulse of L. laricina seedling establishment has occurred at and above the treeline. Dendrochronological analysis revealed that L. laricina underwent a rapid vertical growth and radial growth that accelerated from the 1990s. No recruitment was observed for P. mariana in response to the regional warming, suggesting a regeneration failure of this species. Our results indicated that the L. laricina colonization below and above the treeline in recent decades in response to the regional warming should modify the landscape physiognomy of the study area in the near future.

  3. Larix laricina, an Antidiabetic Alternative Treatment from the Cree of Northern Quebec Pharmacopoeia, Decreases Glycemia and Improves Insulin Sensitivity In Vivo

    PubMed Central

    Harbilas, Despina; Vallerand, Diane; Brault, Antoine; Saleem, Ammar; Arnason, John T.; Musallam, Lina; Haddad, Pierre S.

    2012-01-01

    Larix laricina K. Koch is a medicinal plant belonging to traditional pharmacopoeia of the Cree of Eeyou Istchee (Eastern James Bay area of Canada). In vitro screening studies revealed that, like metformin and rosiglitazone, it increases glucose uptake and adipogenesis, activates AMPK, and uncouples mitochondrial function. The objective of this study was to evaluate the antidiabetic and antiobesity potential of L. laricina in diet-induced obese (DIO) C57BL/6 mice. Mice were subjected for eight or sixteen weeks to a high fat diet (HFD) or HFD to which L. laricina was incorporated at 125 and 250 mg/kg either at onset (prevention study) or in the last 8 of the 16 weeks of administration of the HFD (treatment study). L. laricina effectively decreased glycemia levels, improved insulin resistance, and slightly decreased abdominal fat pad and body weights. This occurred in conjunction with increased energy expenditure as demonstrated by elevated skin temperature in the prevention study and improved mitochondrial function and ATP synthesis in the treatment protocol. L. laricina is thus a promising alternative and complementary therapeutic approach for the treatment and care of obesity and diabetes among the Cree. PMID:22888363

  4. Larix laricina, an Antidiabetic Alternative Treatment from the Cree of Northern Quebec Pharmacopoeia, Decreases Glycemia and Improves Insulin Sensitivity In Vivo.

    PubMed

    Harbilas, Despina; Vallerand, Diane; Brault, Antoine; Saleem, Ammar; Arnason, John T; Musallam, Lina; Haddad, Pierre S

    2012-01-01

    Larix laricina K. Koch is a medicinal plant belonging to traditional pharmacopoeia of the Cree of Eeyou Istchee (Eastern James Bay area of Canada). In vitro screening studies revealed that, like metformin and rosiglitazone, it increases glucose uptake and adipogenesis, activates AMPK, and uncouples mitochondrial function. The objective of this study was to evaluate the antidiabetic and antiobesity potential of L. laricina in diet-induced obese (DIO) C57BL/6 mice. Mice were subjected for eight or sixteen weeks to a high fat diet (HFD) or HFD to which L. laricina was incorporated at 125 and 250 mg/kg either at onset (prevention study) or in the last 8 of the 16 weeks of administration of the HFD (treatment study). L. laricina effectively decreased glycemia levels, improved insulin resistance, and slightly decreased abdominal fat pad and body weights. This occurred in conjunction with increased energy expenditure as demonstrated by elevated skin temperature in the prevention study and improved mitochondrial function and ATP synthesis in the treatment protocol. L. laricina is thus a promising alternative and complementary therapeutic approach for the treatment and care of obesity and diabetes among the Cree.

  5. CO2 enrichment alters diurnal stem radius fluctuations of 36-yr-old Larix decidua growing at the alpine tree line.

    PubMed

    Dawes, Melissa A; Zweifel, Roman; Dawes, Nicholas; Rixen, Christian; Hagedorn, Frank

    2014-06-01

    To understand how trees at high elevations might use water differently in the future, we investigated the effects of CO2 enrichment and soil warming (separately and combined) on the water relations of Larix decidua growing at the tree line in the Swiss Alps. We assessed diurnal stem radius fluctuations using point dendrometers and applied a hydraulic plant model using microclimate and soil water potential data as inputs. Trees exposed to CO2 enrichment for 9 yr showed smaller diurnal stem radius contractions (by 46 ± 16%) and expansions (42 ± 16%) compared with trees exposed to ambient CO2 . Additionally, there was a delay in the timing of daily maximum (40 ± 12 min) and minimum (63 ± 14 min) radius values for trees growing under elevated CO2 . Parameters optimized with the hydraulic model suggested that CO2 -enriched trees had an increased flow resistance between the xylem and bark, representing a more buffered water supply system. Soil warming did not alter diurnal fluctuation dynamics or the CO2 response. Elevated CO2 altered the hydraulic water flow and storage system within L. decidua trees, which might have contributed to enhanced growth during 9 yr of CO2 enrichment and could ultimately influence the future competitive ability of this key tree-line species.

  6. [Effects of nitrogen fertilization on seasonal dynamics of soil microbial biomass carbon and nitrogen in Larix gmelinii and Fraxinus mandshurica plantations].

    PubMed

    Jia, Shu-xi; Zhao, Yan-li; Sun, Yue; Chen, Li; Wang, Zheng-quan

    2009-09-01

    This paper studied the seasonal dynamics of soil microbial biomass C (Cmic) and N (Nmic), and of bacteria (cfu(b)), fungi (cfu(f)), and actinomyces (cfu(a)) in Larix gmelinii and Fraxinus mandshurica plantations in 2007-2008 under N fertilization. The two-year averaged soil Cmic and Nmic in L. gmelinii plantation were 13.8% and 18.3% lower than those in F. mandshurica plantation, respectively, but the soil Cmic and Nmic in the two plantations had similar seasonal patterns, being the lowest in May and the highest in September. The Cmic and Nmic, and the cfu(b), cfu(r), and cfu(a), were all greater in topsoil (0-10 cm) than in subsoil (10-20 cm), but the seasonal patterns of cfu(b), cfu(f), and cfu(a), were different from those of Cmic and Nmic. N fertilization decreased the Cmic and Nmic, and the cfu(b), cfu(f), and cfu(a), significantly, with the decrements of Cmic and Nmic being 24% and 63% in L. gmelinii plantation, and 51% and 68% in F. mandshurica, respectively, which suggested that N fertilization limited soil microbial biomass and altered soil microbial communities in the two plantations.

  7. [Effects of forest cutting on greenhouse gas emissions from Larix gmelini-Sphagnum swamps in Lesser Xing' an Mountains of Heilongjiang, China].

    PubMed

    Mu, Chang-Cheng; Wu, Yun-Xia; Li, Wan-Shu; Xu, Rui

    2010-02-01

    By using static chamber and gas chromatography methods, this paper studied the effects of clear cutting and selective cutting on the CO2, CH4, and N2O emissions from Larix gmelini-Sphagnum swamp in Lesser Xing' an Mountains. Dramatic changes in the seasonal dynamics of CH4 and N2O emissions were detected in different treatment sites. Control site absorbed CH4 in summer and emitted CH4 in autumn, and absorbed N2O in both summer and autumn; selective cutting site emitted CH4 and N2O mainly in summer; and clear cutting site emitted CH4 in summer and autumn, and absorbed N2O in summer but emitted it in autumn. Cutting pattern had less effects on the seasonal dynamics of CO2 emission. Both on the clear cutting site and on the selective cutting site, the CO2 emission was in order of summer > spring > autumn. Forest cutting altered the source and sink functions of the sites. Control site functioned as a source of CO2 and a weak sink of CH4 or N2O, while forest cutting sites had a decrease of CO2 emission by 25%, and became a weak source of N2O and a weak or strong source of CH4. Compared with that of control site, the Global Warming Potential (GWP) of selective cutting site and clear cutting site was reduced by 24.5% and increased by 3.2%, respectively.

  8. Do centennial tree-ring and stable isotope trends of Larix gmelinii (Rupr.) Rupr. indicate increasing water shortage in the Siberian north?

    PubMed

    Sidorova, Olga Vladimirovna; Siegwolf, Rolf T W; Saurer, Matthias; Shashkin, Alexander V; Knorre, Anastasia A; Prokushkin, Anatoliy S; Vaganov, Eugene A; Kirdyanov, Alexander V

    2009-10-01

    Tree-ring width of Larix gmelinii (Rupr.) Rupr., ratios of stable isotopes of C (delta(13)C) and O (delta(18)O) of whole wood and cellulose chronologies were obtained for the northern part of central Siberia (Tura, Russia) for the period 1864-2006. A strong decrease in the isotope ratios of O and C (after atmospheric delta(13)C corrections) and tree-ring width was observed for the period 1967-2005, while weather station data show a decrease in July precipitation, along with increasing July air temperature and vapor pressure deficit (VPD). Temperature at the end of May and the whole month of June mainly determines tree radial growth and marks the beginning of the vegetation period in this region. A positive correlation between tree-ring width and July precipitation was found for the calibration period 1929-2005. Positive significant correlations between C isotope chronologies and temperatures of June and July were found for whole wood and cellulose and negative relationships with July precipitation. These relationships are strengthened when the likely physiological response of trees to increased CO(2) is taken into account (by applying a recently developed delta(13)C correction). For the O isotope ratios, positive relationships with annual temperature, VPD of July and a negative correlation with annual precipitation were observed. The delta(18)O in tree rings may reflect annual rather than summer temperatures, due to the late melting of the winter snow and its contribution to the tree water supply in summer. We observed a clear change in the isotope and climate trends after the 1960s, resulting in a drastic change in the relationship between C and O isotope ratios from a negative to a positive correlation. According to isotope fractionation models, this indicates reduced stomatal conductance at a relatively constant photosynthetic rate, as a response of trees to water deficit for the last half century in this permafrost region.

  9. Effects of long-term exposure to ammonium sulfate particles on growth and gas exchange rates of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica seedlings

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Masahiro; Otani, Yoko; Li, Peiran; Nagao, Hiroshi; Lenggoro, I. Wuled; Ishida, Atsushi; Yazaki, Kenichi; Noguchi, Kyotaro; Nakaba, Satoshi; Yamane, Kenichi; Kuroda, Katsushi; Sano, Yuzou; Funada, Ryo; Izuta, Takeshi

    2014-11-01

    To clarify the effects of long-term exposure to ammonium sulfate (AS) particles on growth and physiological functions of forest tree species, seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron-size AS particles during two growing seasons from 3 June 2011 to 8 October 2012. The mean sulfate concentration in PM2.5 increased during the exposure inside the chamber in 2011 and 2012 by 2.73 and 4.32 μg SO42- m-3, respectively. No significant effects of exposure to AS particles were detected on the whole-plant dry mass of the seedlings. These results indicate that the exposure to submicrometer AS particles at the ambient level for two growing seasons did not significantly affect the growth of the seedlings. No significant effects of exposure to AS particles were found on the net photosynthetic rate in the leaves or needles of F. crenata, C. sieboldii and L. kaempferi seedlings. Also, in the previous-year needles of C. japonica seedlings, exposure to AS particles significantly reduced the net photosynthetic rate, which may be caused by the reduction in the concentration of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco). On the contrary, in current-year needles of C. japonica seedlings, net photosynthetic rate significantly increased with exposure to AS particles, which may be the result of increases in stomatal conductance and concentrations of Rubisco and chlorophyll. Furthermore, exposure to AS particles correlated with an increase in concentrations of NH4+, free amino acid and total soluble protein, suggesting that AS particles may be deliquesced, absorbed into the leaves and metabolized into amino acid and protein. These results suggest that net photosynthesis in the needles of C. japonica is relatively sensitive to submicron-size AS particles as compared with the other three tree species.

  10. [Soil microorganisms, nutrients and enzyme activity of Larix kaempferi plantation under different ages in mountainous region of eastern Liaoning Province, China].

    PubMed

    Niu, Xiao-yun; Sun, Xiao-mei; Chen, Dong-sheng; Zhang, Shou-gong

    2015-09-01

    We studied the community of soil microorganisms, enzyme activity and soil nutrients under 11-, 20-, 34-and 47-year-old Larix kaempferi plantations in mountainous region of eastern Liaoning Province to discuss the soil biological properties of L. kaempferi plantations of different stand ages and their relationships with soil nutrients. The results showed that the indexes reflecting soil micro-organisms, enzyme activity and soil nutrients of L. kaempferi plantations were the highest under the 11- or 47-year-old stand and the lowest in the 20- or 34-year-old stand. Soil productivity appeared in a decline trend with the increasing stand age, and the changes of soil microbial community structure and enzyme activity were responsive to soil degradation. The difference of fungi community was more noticeable than that of bacteria community among the plantations with different stand ages. The results of CCA showed soil nutrient and pH had no effect on seasonal difference of community structure, but had effects on community, structure among different stand ages. The total N, organic carbon, C/N, available nitrogen, exchangeable Mg2+ and pH had greater effects on bacteria community, while available P, total K and pH had greater effect on fungi community among different age forests. The main T-RFs of bacteria and fungi had higher correlation with N and P, and the fungi community had higher correlation with organic carbon and K than bacteria community. The microor-ganism community of the 11- and 47-year-old stands had greater correlation with soil nutrients and enzyme activity than that of 20- and 34-year-old stands. Consequently, soil organisms, in particular soil fungi, could be used to indicate soil degradation.

  11. Does the Genotype Have a Significant Effect on the Formation of Intra-Annual Density Fluctuations? A Case Study Using Larix decidua from Northern Poland

    PubMed Central

    Klisz, Marcin; Koprowski, Marcin; Ukalska, Joanna; Nabais, Cristina

    2016-01-01

    Intra-annual density fluctuations (IADFs) can imprint environmental conditions within the growing season and most of the research on IADFs has been focused on their climatic signal. However, to our knowledge, the genetic influence on the frequency and type of IADFs has not been evaluated. To understand if the genotype can affect the formation of IADFs we have used a common garden experiment using eight families of Larix decidua established in two neighboring forest stands in northern Poland. Four types of IADFs were identified using X-ray density profiles: latewood-like cells within earlywood (IADF-type E), latewood-like cells in the transition from early- to latewood (IADF type E+), earlywood-like cells within latewood (IADF-type L), and earlywood-like cells in the border zone between the previous and present annual ring (IADF-type L+). The influence of explanatory variables i.e., families, sites, and years on identified density fluctuations was analyzed using generalized estimating equations (GEE). We hypothesized that trees from different families will differ in terms of frequency and type of IADFs because each family will react to precipitation and temperature in a different way, depending on the origin of those trees. The most frequent fluctuation was E+ and L types on both sites. The most important factors in the formation of IADFs were the site and year, the last one reflecting the variable climatic conditions, with no significant effect of the family. However, the relation between the formation of IADFs and selected climate parameters was different between families. Although, our results did not give a significant effect of the genotype on the formation of IADFs, the different sensitivity to climatic parameters among different families indicate that there is a genetic influence. PMID:27242883

  12. [Impact of fire on carbon dynamics of Larix gmelinii forest in Daxing'an Mountains of North-East China: a simulation with CENTURY model].

    PubMed

    Fang, Dong-Ming; Zhou, Guang-Sheng; Jiang, Yan-Ling; Jia, Bing-Rui; Xu, Zhen-Zhu; Sui, Xing-Hua

    2012-09-01

    Fire is one of the important natural disturbances to forest ecosystem, giving strong impact on the ecosystem carbon dynamics. By using CENTURY model, this paper simulated the responses of the carbon budget of Larix gmelinii forest in Huzhong area of Daxing' an Mountains to different intensities of fire. The results indicated that after the fires happened, the soil total carbon pool of the forest had a slight increase in the first few years and then recovered gradually, while the stand biomass carbon pool increased after an initial decrease, with the recovery rate of carbon pool of the stand fine components being faster than that of the coarse components. The fluctuation of the carbon pools increased with the increase of fire intensity. After the fires, both the net primary productivity (NPP) of forest vegetation and the soil heterotrophic respiration increased after an initial decrease, but the recovery rate of the NPP was faster than that of soil heterotrophic respiration, resulting in the alternation of the stand functioned as a carbon source or sink. After light fire, the forest still functioned as a weak carbon sink, and quickly recovered as a carbon sink to the level before the fire happened. After other intensities fire, the forest functioned as a carbon source within 9-12 years, and then turned back to a carbon sink again. It was suggested that lower intensity forest fire could promote the regeneration of L. gmelinii forest, reduce the combustibles, and have no strong impact on the stand carbon budget, while higher intensity forest fire would lead to the serious loss of soil- and tree carbon sequestration, retard the recovery of the forest, and thereby, the forest would be a carbon source in a longer term.

  13. NPP changes of Larix chinensis estimated by tree-ring data and its response to climate change in the northern and southern slopes of Mt. Taibai, central China

    NASA Astrophysics Data System (ADS)

    Fang, O.; Xuemei, S.

    2015-12-01

    Larix chinensis is mainly distributed in timberline of Mt. Taibai in the Qinling Mountains, a critical geographic demarcation for climate and vegetation distribution in China. Combined with biomass equations and the annual diameter at breast height calculated from tree-ring widths and investigation data of sampling plots, annual biomass and net primary productivity (NPP) of L. chinensis in northern and southern slopes were estimated. Correlation and response analyses were used to illustrate the relationship between the climate and NPP. The results show that from 1949 to 2014, the biomass of L. chinensis in the pure forests increases from 54.03 to 94.43 t/ha in the northern slope and 28.32 to 55.80 t/ha in the southern slope. The NPP of L. chinensis in northern and southern slopes has varied concordantly over the past 65 years, with an average value of 0.62 and 0.42 t/(ha·a) respectively. The difference in NPPs between the northern and southern slope is decreasing for the slight decrease trend of NPP in northern slope. Temperature plays an important role in the growth of L. chinensis. Low temperature before the growing seasons (from pervious November to April) and warm conditions in the growing seasons (mainly from June to July) can increase the growth of L. chinensis. However, the relationships between NPP and temperature are different in the northern and southern slope. The NPP in southern slope is more positively correlated with the temperature in the growing seasons and there is no significant correlation relationship between the NPP and the temperature in previous winter (from pervious November to January), while the NPP in northern slope is more negatively correlated with the temperature before the growing seasons. These results will provide useful information for the future research of forest carbon cycling.

  14. Reconstructed summer Palmer Drought Severity Index since 1850 AD based on δ13C of larch tree rings in eastern Siberia

    NASA Astrophysics Data System (ADS)

    Tei, Shunsuke; Yonenobu, Hitoshi; Sugimoto, Atsuko; Ohta, Takeshi; Maximov, Trofim C.

    2015-10-01

    We present a tree-ring reconstruction of Palmer Drought Severity Index (PDSI) in Ust-Maya region (60°00‧N, 133°49‧E), central part of eastern Siberia using total ring (TR) widths and latewood (LW) δ13C chronologies from larch trees (1850-2008 AD). Summer (JJA) PDSI was correlated positively and negatively with the TR widths and LW δ13C, respectively. Using a multiple liner regression approach, we reconstructed summer PDSI using the time series of TR widths and LW δ13C. The reconstruction showed an interannual to decadal wet/dry fluctuation with several moist periods before 1950s and a severe drought event from 1991 to 1993. Comparison of the reconstruction with reconstructed July PDSI for the Yakutsk region, 300 km northwest of Ust-Maya, showed heterogeneous changes in the mean states of soil moisture, but synchronous year-to-year changes. These results indicate that regional studies are quite important to precisely depict the spatio-temporal variability of hydrological changes in the central part of eastern Siberia.

  15. Soil sustainability study in Lithuanian alien forest stands

    NASA Astrophysics Data System (ADS)

    Čiuldiene, Dovile; Skridlaite, Grazina; Žalūdiene, Gaile; Askelsson, Cecilia; Armolaitis, Kestutis

    2016-04-01

    Tree species are shifting their natural ranges in response to climate changes (Saltré et al., 2013). Northern red oak has originated from North America, but was planted in Europe already in twentieth century. At present, it is considered as invasive species in Poland and at invasive stage in the Lithuanian forests (Riepsas and Straigyte, 2008). European larch naturally grows in Central Europe, but its range has been extended by planting it as far as the Nordic countries. According to a pollen study in peat soils, European larch naturally grew in Lithuania in the sixteenth century and was reintroduced 200 years ago (Jankauskas, 1954). Therefore, the global warming could accelerate the expansion of European larch and Northern red oak into Lithuanian forests. An urgent need appeared to evaluate an impact of those warmth-tolerant species on soil mineral chemistry and quality. New results on the determination of mineral weathering rates in alien forest stands using a PROFILE soil chemistry model were obtained during a doctoral study at the Institute of Forestry. Soil minerals were studied by a Scanning Electron Microscopy at the Institute of Geology and Geography. The results provided a lot of new information on soil weathering rates in Lithuania. The 47 and 157-year-old European larch (Larix decidua Mill.), 45 and 55-year-old Northern red oak (Quercus rubra L.) plantations and adjacent perennial grasslands were chosen for this study. The soils were classified as Luvisols and were developed from glaciofluvial deposits. The PROFILE model requires data of climate conditions (mean annual temperature and precipitation), chemical parameters of atmospheric deposition, forest plantation dendrometric and chemical (wood, foliage litter fall) characteristics, soil physical characteristics and mineral composition. A cation weathering rate (sum of Ca+Mg+ K) is 30% higher in a soil under the Northern red oak than in adjacent perennial grassland. Meanwhile, cation weathering rates

  16. Larix laricina bark, a traditional medicine used by the Cree of Eeyou Istchee: Antioxidant constituents and in vitro permeability across Caco-2 cell monolayers.

    PubMed

    Yong, Yi; Saleem, Ammar; Guerrero-Analco, José A; Haddad, Pierre S; Cuerrier, Alain; Arnason, John T; Harris, Cory S; Johns, Tim

    2016-12-24

    Larix laricina, a native tree of North America, is a highly respected medicinal plant used for generations by Indigenous Peoples across its range, including the Cree of northern Québec who use the bark to treat symptoms of diabetes. This study investigates the antioxidant capacity and bioavailability of active constituents identified in L. laricina bark extracts. (1) Oxygen radical absorbance capacity (ORAC) assay was employed to test antioxidant capacity of organic extracts (80% ethanol) from bark of L. laricina as well as fractions, isolated compounds, and media samples collected during permeability assays. (2) Caco-2 cell monolayer cultures were used to determine the permeability of identified antioxidants, which were quantified in basolateral media samples using liquid chromatography - tandem mass spectrometry (HPLC-ESI-MS/MS). Crude ethanolic extract possessed strong antioxidant potential in vitro (7.1±0.3 Trolox equivalents (TE) μM/mg). Among the 16 L. laricina fractions obtained by chromatographic separation, fraction 10 (F10) showed the highest antioxidant capacity (21.8±1.7µm TE/mg). Among other identified antioxidants, the stilbene rhaponticin (isolated from F10) was the most potent (24.6±1.1µm TE/mg). Caco-2 transport studies revealed that none of the identified compounds were detectable in basolateral samples after 2-h treatment with crude extract. In monolayers treated with F10 (60% rhaponticin), small quantities of rhaponticin were increasingly detected over time in basolateral samples with an apparent permeability coefficient (Papp) of 1.86×10(-8)cm/s (0-60min). To model potential effects on blood redox status, we evaluated the antioxidant capacity of collected basolateral samples and observed enhanced activity over time after exposure to both extract and F10 (75μg/mL) relative to control. By profiling the antioxidant constituents of L. laricina bark, we identified rhaponticin as the most potent oxygen radical scavenger and observed low

  17. [Interannual variation patterns of heavy metals concentrations in tree rings of Larix gmelinii near Xilin Lead-zinc Mine, Yichun of Northeast China].

    PubMed

    Hu, Shen; Wang, Xiao-Chun; Yang, Jin-Yan

    2013-06-01

    By using dendro-environmental methods, this paper measured and analyzed the variations of five heavy metals (Pb, Cd, Zn, Cu, and Mn) concentrations in the tree rings of Larix gmelinii near Xilin Lead-zinc Mine, Yichun of Northeast China. Among the test heavy metals, the Mn concentration in the tree rings was the highest, while the Cd concentration was the lowest. The Cd, Zn, and Cu concentrations in the tree rings near the ground (0.3 m high from the ground, D0.3) were significantly higher than those at breast height (1.3 m high from the ground, D1.3), while the Pb and Mn concentrations at the two heights had less difference. In 1987-2010, the Pb concentration in the tree rings had a slight increase, but the Cd, Zn, Cu, and Mn concentrations presented a decreasing trend. The Cd concentration decreased most obviously, while the Zn, Cu, and Mn concentrations decreased after an initial increase. With the increase of tree ring width, the Pb concentration decreased, while the Cd, Zn, Cu, and Mn concentrations were in adverse. The relationships between the Pb and other four heavy metals concentrations in the tree rings near the ground and at breast height had definite differences. Near the ground, the Pb concentration showed a significant positive correlation with the other four heavy metals concentrations, but at breast height, less correlation was observed, and even, the Cd concentration decreased significantly with increasing Pb concentration. The variations of the heavy metals concentrations in the L. gmelinii tree rings could be affected by the production and mining activities of Xilin Lead-zinc Mine, an thus, it would be possible to use the Pb concentration in the tree rings to reconstruct the mining his tory of the study area. At present, the Pb concentration in the tailing wastes has polluted the surrounding environments near Xilin Lead-zinc Mine. Therefore, countermeasures should be adopted to manage the heavy metals in tailing wastes if the Mine would be

  18. European biofuel plan snagged

    SciTech Connect

    Chynoweth, E.

    1992-12-16

    European Commission proposals for a directive aimed at boosting production of biofuels have been set back by the European Parliament and will not be implemented on the January 1, 1993 deadline. Furthermore, the commission has agreed to carry out an environmental impact study on biofuels. European industrial ethanol, fatty acid, and glycerin producers oppose the directive proposals fearing distortions in their markets.

  19. European Elder (Elderberry)

    MedlinePlus

    ... Common Names: European elder, black elder, elderberry, elder flower, sambucus Latin Name: Sambucus nigra Background European elder ... Saxon word “aeld,” meaning fire. The terms “elder flower” and “elderberry” may refer to either European elder ...

  20. Secondary formation of oxalic acid and related organic species from biogenic sources in a larch forest at the northern slope of Mt. Fuji

    NASA Astrophysics Data System (ADS)

    Mochizuki, Tomoki; Kawamura, Kimitaka; Miyazaki, Yuzo; Wada, Ryuichi; Takahashi, Yoshiyuki; Saigusa, Nobuko; Tani, Akira

    2017-10-01

    To better understand the formation of water-soluble organic aerosols in the forest atmosphere, we measured low molecular weight (LMW) dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, unsaturated fatty acids (UFAs), and water-soluble organic carbon (WSOC) in aerosols from a Larix kaempferi forest located at the northern slope of Mt. Fuji, Japan, in summer 2012. Concentrations of dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and WSOC showed maxima in daytime. Relative abundance of oxalic acid in LMW dicarboxylic acids was on average 52% and its average concentration was 214 ng m-3. We found that diurnal and temporal variations of oxalic acid are different from those of isoprene and α-pinene, whereas biogenic secondary organic aerosols (BSOAs) derived from isoprene and α-pinene showed similar variations with oxalic acid. The mass concentration ratios of oxalic acid/BSOAs were relatively constant, although a large variation in the concentrations of toluene that is an anthropogenic volatile organic compound was observed. These results suggest that formation of oxalic acid is associated with the oxidation of isoprene and α-pinene with O3 and other oxidants in the forest atmosphere. In addition, concentrations of UFAs were observed, for the first time, to decrease dramatically during daytime in the forest. Mass concentration ratios of azelaic acid to UFAs showed a positive correlation with O3, suggesting that UFAs are oxidized to yield azelaic acid, which may be further decomposed to oxalic acid in the forest atmosphere. We found that contributions of oxalic acid to WSOC are significantly high ranging from 3.7 to 9.7% (average 6.0%). This study demonstrates that forest ecosystem is an important source of oxalic acid and other dicarboxylic acids in the atmosphere.

  1. Reconstruction of soil moisture for the past 100 years in eastern Siberia by using δ13C of larch tree rings

    NASA Astrophysics Data System (ADS)

    Tei, Shunsuke; Sugimoto, Atsuko; Yonenobu, Hitoshi; Yamazaki, Takeshi; Maximov, Trofim C.

    2013-07-01

    stable carbon isotope ratio (δ13C) chronology for the past 100 years was developed from larch tree rings in eastern Siberia (near Yakutsk, 62°14'N, 129°37'E), to reconstruct past soil moisture water equivalent (SWE). Based on the correlation analyses between SWE and tree ring δ13C, we developed a linear regression model for SWE in the late growing period (LGP: 15 July to 31 August) using annual tree ring δ13C, which was calculated from the combination of latewood in a current year and earlywood in the following year, and then reconstructed SWE (LGP) for 1908-2007. Reconstructed SWE was compared with factors such as the output of the land surface model, annual precipitation, and Palmer Drought Severity Index for July. From the results, the reconstructed SWE appears reasonable and shows a large variation, including repeated occurrences of severe drought and an unprecedented high soil moisture event in 2006-2007 during the past 100 years. The reconstruction also captured a past documented record of severe drought in the 1940s. Despite the generally good performance of the reconstruction, by the 1930s the estimated SWE was higher than that expected from the annual precipitation. Tree ring width and δ13C were negatively correlated in most periods. However, the negative correlation was weaker for the period from 1919 to 1925, when relatively low air temperature was observed. This result suggests that the rate of photosynthesis, together with the degree of stomata opening, also affected the tree ring δ13C during cool periods.

  2. The effects of cleared larch canopy and nitrogen supply on gas exchange and leaf traits in deciduous broad-leaved tree seedlings.

    PubMed

    Kitaoka, Satoshi; Watanabe, Yoko; Koike, Takayoshi

    2009-12-01

    To understand the leaf-level responses of successional tree species to forest gap formation and nitrogen deposition, we performed canopy clearing and nitrogen-amendment treatments in larch plantations and investigated the changes in the light-use characteristics and the leaf structure of the invading deciduous broad-leaved tree seedlings. We hypothesized that the responses of the tree seedlings to clearing and nitrogen input would reflect specific traits in the shoot development that would be related to the species-specific successional characteristics. The gap phase species Magnolia hyporeuca Siebold et Zucc. and the mid-late successional tree species Quercus mongolica Fischer ex Ledeb. var. crispula (Blume) Ohashi., which grow in or near the forest gaps, had higher light-saturated photosynthetic rates (Psat), enhanced mesophyll surface area (Smes) and increased leaf mass per area (LMA) under both the clearing treatment and the clearing with nitrogen-amendment treatment. These two species therefore increased their Psat via an increase in Smes and LMA. The LMA values of the late successional tree species Prunus ssiori F. Schmidt and Carpinus cordata Blume, which grow in the forest understory, were enhanced by the clearing treatment. However, they displayed lesser responses to the clearing treatment under which there were no marked increases in Psat or Smes values in the second year. These results indicate distinct and varied responses to disturbance regimes among the four seral tree seedlings. The Psat value largely increased in line with the increase in Smes value during the second year in M. hyporeuca and Q. mongolica. The nitrogen supply accelerated the change in LMA and increased the Smes value in the leaves of Q. mongolica.

  3. Characterization of an exo-β-1,3-D: -galactanase from Sphingomonas sp. 24T and its application to structural analysis of larch wood arabinogalactan.

    PubMed

    Sakamoto, Tatsuji; Tanaka, Hiromasa; Nishimura, Yuichi; Ishimaru, Megumi; Kasai, Naoya

    2011-06-01

    A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 °C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 °C, respectively. Galactose was released from β-1,3-D: -galactan and β-1,3-D: -galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-β-1,3-D: -galactanase. Analysis of the reaction products of β-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of β-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, β-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be β-1,6-galactotriose and β-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.

  4. Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China

    PubMed Central

    Li, Hailiang; C. Crabbe, M. James; Wang, Weiling; Ma, Lihui; Niu, Ruilong; Gao, Xing; Li, Xingxing; Zhang, Pei; Ma, Xin; Chen, Haikui

    2017-01-01

    Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. We used long-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L. principis-rupprechtii Mayr. plantation from 2012–2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type and sampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P and N:P throughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:N and C:P but lower N and N:P, and the roots had greater P and C:N but lower N, C:P and N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes a valuable contribution to the global data pool on leaf nutrition and stoichiometry. PMID:28938020

  5. Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China.

    PubMed

    Li, Hailiang; C Crabbe, M James; Xu, Fuli; Wang, Weiling; Ma, Lihui; Niu, Ruilong; Gao, Xing; Li, Xingxing; Zhang, Pei; Ma, Xin; Chen, Haikui

    2017-01-01

    Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. We used long-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L. principis-rupprechtii Mayr. plantation from 2012-2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type and sampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P and N:P throughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:N and C:P but lower N and N:P, and the roots had greater P and C:N but lower N, C:P and N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes a valuable contribution to the global data pool on leaf nutrition and stoichiometry.

  6. High-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry and gas chromatography-flame ionization detection characterization of Delta5-polyenoic fatty acids in triacylglycerols from conifer seed oils.

    PubMed

    Lísa, Miroslav; Holcapek, Michal; Rezanka, Tomás; Kabátová, Nadezda

    2007-03-30

    Edible conifer seeds can serve as a source of triacylglycerols (TGs) with unusual Delta5 unsaturated polymethylene interrupted fatty acids (UPIFAs), such as cis-5,9-octadecadienoic (taxoleic), cis-5,9,12-octadecatrienoic (pinolenic), cis-5,11-eicosadienoic (keteleeronic) and cis-5,11,14-eicosatrienoic acids (sciadonic). Conifer seed oils from European Larch (Larix decidua), Norway Spruce (Picea abies) and European Silver Fir (Abies alba) have been analyzed by non-aqueous reversed-phase high-performance liquid chromatography (NARP-HPLC) with atmospheric pressure chemical ionisation (APCI)-MS detection. The influence of different positions of double bonds in Delta5-UPIFAs on the retention and fragmentation behavior is described and used for the successful identification of TGs in each oil. TGs containing Delta5-UPIFAs have a higher retention in comparison with common TGs found in plant oils with single methylene interrupted Delta6(9)-FAs and also significantly changed relative abundances of fragment ions in APCI mass spectra. Results obtained from HPLC/MS analyses are supported by validated GC/FID analyses of fatty acid methyl esters after the transesterification. The total content of Delta5-UPIFAs is about 32% for European Larch, 27% for Norway Spruce and 20% for European Silver Fir. In total, 20 FAs with acyl chain lengths from 16 to 24 carbon atoms and from 0 to 3 double bonds have been identified in 64 triacylglycerols from 3 conifer seed oils.

  7. Carbon Allocation of 13CO2-labeled Photoassimilate in Larix gmelinii Saplings - A Physiological Basis for Isotope Dendroclimatology in Eastern Siberia.

    NASA Astrophysics Data System (ADS)

    Kagawa, A.; Sugimoto, A.; Maximov, T. C.

    2006-12-01

    also relied on stored material in some cases. Carbon isotope chronology of recent 100 years shows that the latewood 13C contains stronger climate signal than the earlywood and is significantly correlated to July temperature and July precipitation, corresponding to the timing of carbon incorporation that constitutes latewood. The results suggest the need for separating earlywood and latewood for isotope dendroclimatological study in Siberia. References: 1) Kagawa A., Sugimoto A., & Maximov, T.C. (2006) 13CO2 pulse-labelling of photoassimilates reveals carbon allocation within and between tree rings. Plant, Cell and Environment 29, 1571-1584. 2) Kagawa A., Sugimoto A., & Maximov, T. C. (2006) Seasonal course of translocation, storage, and remobilization of 13C pulse-labeled photoassimilate in naturally growing Larix gmelinii saplings. New Phytologist 171, 793-804. 3) Kagawa A., Naito D., Sugimoto A. & Maximov T. C. (2003) Effects of spatial and temporal variability in soil moisture on widths and 13C values of eastern Siberian tree rings. Journal of Geophysical Research 108 (D16), 4500, doi:10.1029/2002JD003019.

  8. 7 CFR 301.91-3 - Regulated areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES European Larch Canker Quarantine and Regulations § 301..., in which European larch canker has been found by an inspector or in which the Deputy Administrator has reason to believe that European larch canker is present, or any portion of a quarantined State...

  9. 7 CFR 301.91-3 - Regulated areas.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES European Larch Canker Quarantine and Regulations § 301..., in which European larch canker has been found by an inspector or in which the Deputy Administrator has reason to believe that European larch canker is present, or any portion of a quarantined State...

  10. 7 CFR 301.91-3 - Regulated areas.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES European Larch Canker Quarantine and Regulations § 301..., in which European larch canker has been found by an inspector or in which the Deputy Administrator has reason to believe that European larch canker is present, or any portion of a quarantined...

  11. 7 CFR 301.91-3 - Regulated areas.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES European Larch Canker Quarantine and Regulations § 301..., in which European larch canker has been found by an inspector or in which the Deputy Administrator has reason to believe that European larch canker is present, or any portion of a quarantined...

  12. 7 CFR 301.91-3 - Regulated areas.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES European Larch Canker Quarantine and Regulations § 301..., in which European larch canker has been found by an inspector or in which the Deputy Administrator has reason to believe that European larch canker is present, or any portion of a quarantined...

  13. [Biobanks European infrastructure].

    PubMed

    Kinkorová, Judita; Topolčan, Ondřej

    2016-01-01

    Biobanks are structured repositories of human tissue samples connected with specific information. They became an integral part of personalized medicine in the new millennium. At the European research area biobanks are isolated not well coordinated and connected to the network. European commission supports European infrastructure BBMRI-ERIC (Biobanks and Biomolecular Resources Research Infrastructure European Research Infrastructure Consortium), consortium of 54 members with more than 225 associated organizations, largely biobanks from over 30 countries. The aim is to support biomedical research using stored samples. Czech Republic is a member of the consortium as a national node BBMRI_CZ, consisting of five partners.

  14. Environmental factors controlling forest evapotranspiration and surface conductance on a multi-temporal scale in growing seasons of a Siberian larch forest

    NASA Astrophysics Data System (ADS)

    Yoshida, Megumi; Ohta, Takeshi; Kotani, Ayumi; Maximov, Trofim

    2010-12-01

    SummaryThe water and energy fluxes in forests fluctuate on different temporal scales, reflecting the impact of environmental factors. We examined the temporal fluctuation of the turbulent fluxes, surface conductance ( Gs), and four environmental factors (photosynthetic photon flux density [ Q], vapour pressure deficit [ D], air temperature [ T], and volumetric soil water content [ θ]) in a Siberian larch forest, using wavelet power spectra. The responses of the latent heat flux ( λE) and Gs to the environmental factors were analysed using the wavelet scale-wise correlation coefficient (SWCC) on multiple temporal scales. The observation site is characterised by underlying permafrost and a relatively short growing season. Analysis was conducted from May to September in each of 8 years during 1998-2007. The relationships between Gs and the environmental factors were evaluated with restrictive functions of a Jarvis-type surface conductance model because Gs usually has non-linear relationships to ambient factors. According to the power spectra of each factor, the largest variation was seen on a diurnal timescale for λE, the sensible heat flux ( H), Gs, and Q, whereas D and T fluctuated from diurnal to inter-seasonal timescales, and θ varied significantly over periods longer than the inter-seasonal timescales. The SWCC indicated that λE and Gs respond differently to the same ambient factors due to their respective processes; namely, λE is affected by both atmospheric demand and land surface regulation, whereas Gs is affected only by the latter. λE correlated well with Q at all timescales, as well as with D and T on intra-seasonal to interannual scales and with θ on inter-seasonal to interannual timescales. The SWCC of Gs and Q showed two peaks, on diurnal and inter-seasonal to interannual timescales, reflecting the physiological processes of plants, and D affected Gs only on an intra-seasonal timescale, which is related to meteorological changes. T and

  15. European auxiliary propulsion, 1972

    NASA Technical Reports Server (NTRS)

    Holcomb, L. B.

    1972-01-01

    The chemical and electric auxiliary propulsion technology of the United Kingdom, France, and West Germany is discussed in detail, and the propulsion technology achievements of Italy, India, Japan, and Russia are reviewed. A comparison is presented of Shell 405 catalyst and a European spontaneous hydrazine catalyst called CNESRO I. Finally, conclusions are drawn regarding future trends in European auxiliary propulsion technology development.

  16. Contrasting patterns of nucleotide diversity for four conifers of Alpine European forests

    PubMed Central

    Mosca, Elena; Eckert, Andrew J; Liechty, John D; Wegrzyn, Jill L; La Porta, Nicola; Vendramin, Giovanni G; Neale, David B

    2012-01-01

    A candidate gene approach was used to identify levels of nucleotide diversity and to identify genes departing from neutral expectations in coniferous species of the Alpine European forest. Twelve samples were collected from four species that dominate montane and subalpine forests throughout Europe: Abies alba Mill, Larix decidua Mill, Pinus cembra L., and Pinus mugo Turra. A total of 800 genes, originally resequenced in Pinus taeda L., were resequenced across 12 independent trees for each of the four species. Genes were assigned to two categories, candidate and control, defined through homology-based searches to Arabidopsis. Estimates of nucleotide diversity per site varied greatly between polymorphic candidate genes (range: 0.0004–0.1295) and among species (range: 0.0024–0.0082), but were within the previously established ranges for conifers. Tests of neutrality using stringent significance thresholds, performed under the standard neutral model, revealed one to seven outlier loci for each species. Some of these outliers encode proteins that are involved with plant stress responses and form the basis for further evolutionary enquiries. PMID:23144662

  17. Contrasting patterns of nucleotide diversity for four conifers of Alpine European forests.

    PubMed

    Mosca, Elena; Eckert, Andrew J; Liechty, John D; Wegrzyn, Jill L; La Porta, Nicola; Vendramin, Giovanni G; Neale, David B

    2012-11-01

    A candidate gene approach was used to identify levels of nucleotide diversity and to identify genes departing from neutral expectations in coniferous species of the Alpine European forest. Twelve samples were collected from four species that dominate montane and subalpine forests throughout Europe: Abies alba Mill, Larix decidua Mill, Pinus cembra L., and Pinus mugo Turra. A total of 800 genes, originally resequenced in Pinus taeda L., were resequenced across 12 independent trees for each of the four species. Genes were assigned to two categories, candidate and control, defined through homology-based searches to Arabidopsis. Estimates of nucleotide diversity per site varied greatly between polymorphic candidate genes (range: 0.0004-0.1295) and among species (range: 0.0024-0.0082), but were within the previously established ranges for conifers. Tests of neutrality using stringent significance thresholds, performed under the standard neutral model, revealed one to seven outlier loci for each species. Some of these outliers encode proteins that are involved with plant stress responses and form the basis for further evolutionary enquiries.

  18. The European Spallation Source

    SciTech Connect

    Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

    2011-04-20

    In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

  19. European journals on microbiology.

    PubMed

    Ronda, C; Vázquez, M

    1997-12-01

    A survey on the scientific journals dealing with microbiology published in Europe has been carried out. Eighteen European countries publish microbiological journals with the United Kingdom. Netherlands and Germany leading in number of journals on this specialty. Most of the European journals on microbiology are published bimonthly (27%), and English is the most common language used (54%). Most of these journals (86%) are included in some database, but only 36 (25%) are indexed in the six databases studied. Out of the 146 journals registered, 71 (49%), published in 11 European countries, are included in the 1995 Journal Citation Reports (ISI, Philadelphia).

  20. The European experience.

    PubMed

    Roels, Leo; Rahmel, Axel

    2011-04-01

    This mini-review on European experiences with tackling the problem of organ shortage for transplantation was based on a literature review of predominantly European publications dealing with the issue of organ donation from deceased donors. The authors tried to identify the most significant factors that have demonstrated to impact on donation rates from deceased donors and subsequent transplant successes. These factors include legislative measures (national laws and European Directives), optimization of the donation process, use of expanded criteria donors, innovative preservation and surgical techniques, organizational efforts, and improved allocation algorithms.

  1. European Stroke Science Workshop

    PubMed Central

    Mattle, Heinrich P.; Brainin, Michael; Chamorro, Angel; Diener, Hans Christoph; Hacke, Werner; Leys, Didier; Norrving, Bo; Ward, Nick

    2012-01-01

    The European Stroke Organisation (ESO) held its first European Stroke Science Workshop in Garmisch-Partenkirchen, Germany (15-17 December 2011). Stroke experts based in Europe were invited to present and discuss their current research. The scope of the workshop was to review the most recent findings of selected topics in stroke, to exchange ideas, to stimulate new research and to enhance collaboration between European stroke research groups. Seven scientific sessions were held, each starting with a keynote lecture to review the state of the art of the given topic, followed by 4 or 5 short presentations by experts. They were asked to limit their presentations to 10 slides containing only recent information. The meeting was organized by the executive committee of the ESO (Heinrich Mattle, chairman, Michael Brainin, Angel Chamorro, Werner Hacke, Didier Leys) and supported by the European Stroke Conference (Michael Hennerici). In this article we summarize the main contents of this successful workshop. PMID:22836350

  2. European PTTI report

    NASA Technical Reports Server (NTRS)

    Cordara, Franco; Grimaldi, Sabrina; Leschiutta, Sigfrido

    1994-01-01

    Time and frequency metrology in Europe presents some peculiar features in its three main components: research on clocks, comparisons and dissemination methods, and dissemination services. Apart from the usual activities of the national metrological laboratories, an increasing number of cooperation between the European countries are promoted inside some European organizations, such as the ECC, EFTA, EUROMET, and WECC. Cooperation between these organizations is covered. The present, evolving situation will be further influenced by the recent political changes in Eastern Europe.

  3. Preliminary Guide to the Onsite Identification and Delineation of the Wetlands of the North Atlantic United States.

    DTIC Science & Technology

    1982-05-01

    Leatherleaf) Chamaecyparis thyoides (Atlantic white cedar) Fraxinus pennsylvanica (Green ash) Larix laricina (Tamarack) Osmunda spp. (Cinnamon fern...spp. Laurel Kochia scoparia (L.) Schrad. Summer cypress Kosteletzkya virginica (L.) Presl ex Gray Marsh mallow Larix laricina (Du Roi) K. Koch Larch...f Cyperus spp. (Sedges) b PAcea mariana (Black Spru~.e) g Nymphaea odorata (Waterlily) c Lanax laricina (Tamarack) h Myrica gale (Sweet Gale) d

  4. European Education, European Citizenship? On the Role of Education in Constructing Europeanness.

    ERIC Educational Resources Information Center

    Ollikainen, Aaro

    2000-01-01

    Focuses on the role of the European Union (EU) education programs in fostering a sense of European citizenship. Addresses the five meanings given to the concept of European citizenship: (1) recognition of European heritage; (2) EU loyalty; (3) right of free movement; (4) political participation; and (5) active citizenship. (CMK)

  5. European Universe Awareness

    NASA Astrophysics Data System (ADS)

    Russo, P.; Miley, G.; Westra van Holthe, F.; Schrier, W.; Reed, S.

    2011-10-01

    The European Universe Awareness (EU-UNAWE) programme uses the beauty and grandeur of the cosmos to encourage young children, particularly those from underprivileged backgrounds, to develop an interest in science and technology and to foster a sense of global citizenship. EU-UNAWE is already active in 40 countries and comprises a global network of almost 500 astronomers, teachers and other educators. The programme was recently awarded a grant of 1.9 million euros by the European Union so that it can be further developed in five European countries and South Africa. The grant will be used to organise teacher training workshops and to develop educational materials, such as an astronomy news service for children and games. During this presentation we will outline some of the biggest achievements of EU-UNAWE to date and discuss future plans for the programme.

  6. European Composite Honeycomb Material

    NASA Astrophysics Data System (ADS)

    Tschepe, Christoph; Sauerbrey, Martin; Klebor, Maximillian; Henriksen, Torben

    2014-06-01

    A European CFRP honeycomb material for high demanding structure applications like antenna reflectors and optical benches was developed in the frame of an ESA GSTP project.The composite honeycomb was designed according to requirements defined by the European space industry. A developed manufacturing technique based on prepreg moulding enables the production of homogeneous CFRP honeycomb blocks. All characteristic material properties, including compression, tension and shear strength and CTE, were determined in a comprehensive verification test campaign. Competitiveness to comparable products was further verified by a representative breadboard.

  7. European security and France

    SciTech Connect

    deRose, A.

    1985-01-01

    A French authority on security argues for new European initiatives in the face of the ''danger represented by Soviet military power deployed in support of an imperialistic ideology.'' His proposals, including the strengthening of conventional forces without abandoning the option of the first use of nuclear weapons, are meant to give substance to President Mitterrand's declaration in 1983: ''The European nations now need to realize that their defense is also their responsibility....'' A part of the increasingly important debate in France over defense policy in Europe.

  8. European Music Year 1985.

    ERIC Educational Resources Information Center

    Alexanderson, Thomas; And Others

    1984-01-01

    Articles concerning music are included in this newsletter dedicated to cultural venture to be jointly carried out by the Council of Europe and the European communities. Many events will mark Music Year 1985, including concerts, dance performances, operas, publications, recordings, festivals, exhibitions, competitions, and conferences on musical…

  9. The European VLBI network

    NASA Technical Reports Server (NTRS)

    Schilizzi, R. T.

    1980-01-01

    The capabilities of the European very long baseline interferometry (VLBI) network are summarized. The range of baseline parameters, sensitivities, and recording and other equipment available are included. Plans for upgrading the recording facilities and the use of geostationary satellites for signal transfer and clock synchronization are discussed.

  10. Multilingualism in European Workplaces

    ERIC Educational Resources Information Center

    Gunnarsson, Britt-Louise

    2014-01-01

    This state-of-the-art article includes a review of past and recent studies on multilingualism at work in European environments. One aim is to provide the reader with a cross-cultural picture of workplace studies on various languages in Europe, another to discuss both positive and problem-based accounts of multilingualism at work. The overview…

  11. Teaching European Identities

    ERIC Educational Resources Information Center

    Raento, Pauliina

    2008-01-01

    The political, cultural and social make-up of Europe is changing fast. A new European identity is under construction, but old contradictions and diversity challenge its contents, forms and boundaries. Migration, the changing role of the nation-state and Europe's regions, the reshaping of politico-administrative and perceptional boundaries, the…

  12. European Pine Shoot Moth

    Treesearch

    William E. Miller; Arthur R. Hastings; John F. Wootten

    1961-01-01

    In the United States, the European pine shoot moth has caused much damage in young, plantations of red pine. It has been responsible for reduced planting of red pine in many areas. Although attacked trees rarely if ever die, their growth is inhibited and many are, deformed. Scotch pine and Austrian pine (Pinus nigra Arnold) are usually not so badly damaged. Swiss...

  13. European Civilization. Teacher's Manual.

    ERIC Educational Resources Information Center

    Leppert, Ella C.; Halac, Dennis

    The instructional materials in this teaching guide for Course II, Unit IV, follow and build upon a previous sequential course described in SO 003 169 offering ninth grade students a study on the development of Western European Civilization. Focus is upon four periods of high development: The High Middle Ages (12th Century), The Renaissance (15th…

  14. Trends in European English.

    ERIC Educational Resources Information Center

    Wilkinson, Robert

    It is proposed that a European variety of English without native speakers is emerging as a language of international communication in Europe. This is a consequence of many factors, including the strength of the American economy, the breadth and depth of American research in science and technology, the pervasive influence of American-style popular…

  15. European Civilization. Teacher's Manual.

    ERIC Educational Resources Information Center

    Leppert, Ella C.; Halac, Dennis

    The instructional materials in this teaching guide for Course II, Unit IV, follow and build upon a previous sequential course described in SO 003 169 offering ninth grade students a study on the development of Western European Civilization. Focus is upon four periods of high development: The High Middle Ages (12th Century), The Renaissance (15th…

  16. Teaching European Identities

    ERIC Educational Resources Information Center

    Raento, Pauliina

    2008-01-01

    The political, cultural and social make-up of Europe is changing fast. A new European identity is under construction, but old contradictions and diversity challenge its contents, forms and boundaries. Migration, the changing role of the nation-state and Europe's regions, the reshaping of politico-administrative and perceptional boundaries, the…

  17. Multilingualism in European Workplaces

    ERIC Educational Resources Information Center

    Gunnarsson, Britt-Louise

    2014-01-01

    This state-of-the-art article includes a review of past and recent studies on multilingualism at work in European environments. One aim is to provide the reader with a cross-cultural picture of workplace studies on various languages in Europe, another to discuss both positive and problem-based accounts of multilingualism at work. The overview…

  18. European Study Tour Guidelines.

    ERIC Educational Resources Information Center

    Mitchell, Vicki L.; Mitchell, Kenneth E.

    Guidelines are presented for planning and financing European study tours at the community college level. First, a rationale for incorporating study tours of Europe within the community college curriculum is presented and the benefits of such tours in providing students with experiences they could not normally have are outlined. Next, the paper…

  19. The European Mobile System (EMS)

    NASA Technical Reports Server (NTRS)

    Jongejans, A.; Rogard, R.; Mistretta, I.; Ananasso, F.

    1993-01-01

    The European Space Agency is presently procuring an L band payload in order to promote a regional European L band system coping with the specific needs of the European market. The payload, and the two communications systems to be supported, are described below. The potential market for EMS in Europe is discussed.

  20. Education and European integration

    NASA Astrophysics Data System (ADS)

    Lowe, John

    1992-11-01

    The main purpose of this article is to discuss the implications for education and training of the movement towards integration in Europe in the historic context of the creation of a single market within the European Community (EC) and the end of the Communist regimes in Central and Eastern Europe. The experience of the EC is used to illustrate trends and problems in the development of international cooperation in education and training. Common concerns and priorities throughout the new Europe are then identified and discussed. These include the pursuit of quality in schooling, efforts to serve the interests of disadvantaged learners, and the treatment of European Studies in the curriculum, including the improvement of the teaching of foreign languages.

  1. Chestnut, European (Castanea sativa).

    PubMed

    Corredoira, Elena; Valladares, Silvia; Vieitez, Ana M; Ballester, Antonio

    2015-01-01

    Development of a system for direct transfer of antifungal candidate genes into European chestnut (Castanea sativa) would provide an alternative approach to conventional breeding for production of chestnut trees that are tolerant to ink disease caused by Phytophthora spp. Overexpression of genes encoding PR proteins (such as thaumatin-like proteins), which display antifungal activity, may represent an important advance in control of the disease. We have used a chestnut thaumatin-like protein gene (CsTL1) isolated from European chestnut cotyledons and have achieved overexpression of the gene in chestnut somatic embryogenic lines used as target material. We have also acclimatized the transgenic plants and grown them on in the greenhouse. Here, we describe the various steps of the process, from the induction of somatic embryogenesis to the production of transgenic plants.

  2. Telemedicine and European law.

    PubMed

    Callens, Stefaan

    2003-01-01

    A Directive of the European Union was first published in 2000, which dealt with telemedicine as part of its provisions. This E-Commerce Directive, as it became known, was subjected to further study which revealed some problems relative to the practice of telemedicine. Among the subjects discussed in this paper are those of privacy, data protection, free movement of services, the impact of electronic communication and ethical issues.

  3. The European Spallation Source

    SciTech Connect

    Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.; Satogata, T

    2011-03-01

    The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

  4. Determining modulus of elasticity of ancient structural timber

    Treesearch

    Houjiang Zhang; Lei Zhu; Yanliang Sun; Xiping Wang; Haicheng Yan

    2011-01-01

    During maintenance of ancient timber architectures, it is important to determine mechanical properties of the wood component materials non-destructively and effectively, so that degraded members may be replaced or repaired to avoid structural failure. Experimental materials are four larch (Larix principis-rupprechtii Mayr.) components, which were taken down from the...

  5. Soil alkalinity on recent burns

    Treesearch

    Robert Marshall; Clarence. Averill

    1928-01-01

    During late July and early August, 1926, the Kaniksu National Forest in northern Idaho experienced its most severe fire damage since the advent of the white man in that region. About 125,000 acres were burned as a result of the conflagrations. The destroyed forests consisted largely of western white pine (Pinus mionticola), western larch (Larix occidentalis), Douglas...

  6. Modeling species’ realized climatic niche space and predicting their response to global warming for several western forest species with small geographic distributions

    Treesearch

    Marcus V. Warwell; Gerald E. Rehfeldt; Nicholas L. Crookston

    2010-01-01

    The Random Forests multiple regression tree was used to develop an empirically based bioclimatic model of the presence-absence of species occupying small geographic distributions in western North America. The species assessed were subalpine larch (Larix lyallii), smooth Arizona cypress (Cupressus arizonica ssp. glabra...

  7. Longevity of active Phytophthora ramorum in terminal tree hosts following the removal of primary sporulating hosts

    Treesearch

    Barnaby Wylder; Mick Biddle; Anna Harris; Joan Webber

    2017-01-01

    The Forestry Commission-managed forest estate located in Plym, Devon (southwest England) was one of the first locations in late summer 2009 to have stands of Larix kaempferi (Japanese larch) confirmed as infected with Phytophthora ramorum (EU1 lineage). The 398 ha forest had a high proportion (>30%) of

  8. Bedrock type significantly affects individual tree mortality for various conifers in the inland Northwest, U.S.A

    Treesearch

    James A. Moore; David A Hamilton; Yu Xiao; John Byrne

    2004-01-01

    Individual tree mortality models for western white pine (Pinus monticola Dougl. ex D. Don), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western larch (Larix occidentalis Nutt.) were developed using data...

  9. Changes in tracheid and ray traits in fire scars of North American conifers and their ecophysiological implications

    Treesearch

    Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

    2014-01-01

    Fire scars have been widely used as proxies for the reconstruction of fire history; however, little is known about the impact of fire injury on wood anatomy. This study investigates changes in tracheid and ray traits in fire scars of Douglas fir (Pseudotsuga menziesii), western larch (Larix occidentalis) and ponderosa pine (

  10. Assessing the threat posed by indigenous exotics: A case study of two North American bark beetle species

    Treesearch

    K. J. Dodds; D. W. Gilmore; S. J. Seybold

    2010-01-01

    The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, was detected in 2001 in northern Minnesota outside its natural range and the range of its native hosts, Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco, and western larch, Larix occidentalis Nutt. Consecutive years of...

  11. Cleaning to favor western white pine - its effects upon composition, growth, and potential values

    Treesearch

    Raymond J. Boyd

    1959-01-01

    The management of western white pine (Pinus monticola) requires the production of a high proportion of valuable white pine crop trees in order to defray the costs of protection from blister rust. Current average selling prices of lumber give white pine about $50 per m.b.f. advantage over western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga menziesii), the...

  12. Eastern European risk management

    SciTech Connect

    Honey, J.A. )

    1992-01-01

    Here the authors assess Eastern European risk management practices through the evaluation of the nuclear power plants in the region. This evaluation is limited to the Soviet-designed and -built VVER-440 pressurized water reactors (PWRs) that are currently operating in Bulgaria, Czechoslovakia, Hungary, Russia, and the Ukraine and until recently operated at Greifswald in the former East Germany. This evaluation is based on the basic design of the plants, a safety evaluation of the Greifswald facility by representatives from the Federal Republic of Germany and personal visits by the author to Greifswald and Loviisa.

  13. Biophotonics: a European perspective

    NASA Astrophysics Data System (ADS)

    Robin, Thierry; Cochard, Jacques; Breussin, Frédéric

    2013-03-01

    The objective of the present work is to determine the opportunities and challenges for Biophotonics business development in Europe for the next five years with a focus on sensors and systems: for health diagnostics and monitoring; for air, water and food safety and quality control. The development of this roadmap was initiated and supported by EPIC (The European Photonics Industry Consortium). We summarize the final roadmap data: market application segments and trends, analysis of the market access criteria, analysis of the technology trends and major bottlenecks and challenges per application.

  14. Effects of climatic conditions on radial growth and sap-flow along an elevation gradient in an inner-alpine dry valley

    NASA Astrophysics Data System (ADS)

    Obojes, Nikolaus; Newesely, Christian; Bertoldi, Giacomo; Tassser, Erich; Oberhuber, Walter; Mayr, Stefan; Tappeiner, Ulrike

    2016-04-01

    Water availability in mountain forests might change in the future due to rising temperatures and changing precipitation patterns, affecting tree water relations and growth conditions. Changing temperature and precipitation along an elevation gradient in an inner-alpine dry valley in South Tyrol-Italy were used to investigate possible effects of climate change on the transpiration and growth of European Larch (Larix decidua). Stem circumference variation of European Larch was measured for 4 years (2012-2015) with automatic band dendrometers and sap flow for 2 years (2013-2014) with trunk heat balance sensors at 3 sites at elevations of 1115 m, 1715 m, and 1990 m above sea level at a SE-exposed slope. During the first two, rather dry, years, transpiration and stem circumference were reduced during dry periods of one to three weeks at the two lower but not at the highest site. As a consequence, overall yearly radial growth was largest at the highest site in those two years. In 2014, with very high precipitation and colder summer temperatures no correlation of elevation, transpiration, and radial growth was observed. In 2015, with a dry and hot summer, initially high growth rates were strongly reduced after the end of May at the two lower sites. Overall the radial growth of Larix decidua seems to be limited by water scarcity up to an elevation of more than 1700 m a.s.l. in our study area except for unusually wet years. Our 4-year measurements were confirmed by dendro-climatic analysis of stem cores taken at five sites (the three original ones plus two additional sites at 1070 and at the forest line at 2250m) covering the last 50 to 150 years. Year ring widths were lower and highly correlated to precipitation at the lowest sites, and overall highest at the 1990 m site. Our results show that the growth of Larix decidua, which is often considered as more drought resistant than e.g. Picea abies, is limited by water availability at dry conditions in the Alps which might

  15. The European Infrasound Bulletin

    NASA Astrophysics Data System (ADS)

    Pilger, Christoph; Ceranna, Lars; Ross, J. Ole; Vergoz, Julien; Le Pichon, Alexis; Mialle, Pierrick

    2017-04-01

    The European Infrasound Bulletin highlights infrasound activity produced by mostly anthropogenic sources, recorded all over Europe and collected in the course of the ARISE project (Atmospheric dynamics Research InfraStructure in Europe). Data includes high frequency (>0.7 Hz) infrasound detections of 24 European infrasound arrays from 9 different national institutions (BGR, CEA, IRF, NORSAR, KNMI, UNIFI, IAP-Prague, NIEP, SOREQ) complemented with CTBT IMS infrasound stations. Data was acquired during 16 years of operation (from 2000 to 2015), and processed to identify and localize about 48.000 infrasound events within Europe (20°W-40°E, 30°N-72°N). The source location of these events was derived by combining at least two corresponding station detections per event. Comparisons to ground-truth sources, as e.g. Scandinavian mining activity, are provided. Relocation is performed using ray-tracing methods to estimate celerity and back-azimuth corrections based on either HWM-07/MSISE-00 climatologies or actual ECMWF wind and temperature values for each event. This study focuses on repeating infrasound events (e.g. mining blasts and supersonic flights) and on the seasonal, weekly and diurnal variation of the infrasonic activity of sources in Europe. Estimations of the detection and location capability and accuracy will be given in the course of this study to achieve a comprehensive picture of the activity of infrasound sources and capability of infrasound station in Europe.

  16. European Conference on Health Economics.

    PubMed

    Malmivaara, Antti

    2010-12-01

    The biennial European Conference on Health Economics was held in Finland this year, at the Finlandia Hall in the centre of Helsinki. The European conferences rotate among European countries and fall between the biennial world congresses organized by the International Health Economics Association (iHEA). A record attendance of approximately 800 delegates from 50 countries around the world were present at the Helsinki conference. The theme of the conference was 'Connecting Health and Economics'. All major topics of health economics were covered in the sessions. For the first time, social care economics was included in the agenda of the European Conference as a session of its own.

  17. A New Impetus for European Youth. European Commission White Paper.

    ERIC Educational Resources Information Center

    Commission of the European Communities, Brussels (Belgium).

    Despite their highly divergent situations, young people largely share the same values, ambitions, and difficulties. Despite the more complex social and economic context in which young Europeans are currently living, they are well equipped to adapt. National and European policymakers must facilitate this process of change by making young people…

  18. European Cenozoic rift system

    NASA Astrophysics Data System (ADS)

    Ziegler, Peter A.

    1992-07-01

    The European Cenozoic rift system extends from the coast of the North Sea to the Mediterranean over a distance of some 1100 km; it finds its southern prolongation in the Valencia Trough and a Plio-Pleistocene volcanic chain crossing the Atlas ranges. Development of this mega-rift was paralleled by orogenic activity in the Alps and Pyrenees. Major rift domes, accompanied by subsidence reversal of their axial grabens, developed 20-40 Ma after beginning of rifting. Uplift of the Rhenish Shield is related to progressive thermal lithospheric thinning; the Vosges-Black Forest and the Massif Central domes are probably underlain by asthenoliths emplaced at the crust/mantle boundary. Evolution of this rift system, is thought to be governed by the interaction of the Eurasian and African plates and by early phases of a plate-boundary reorganization that may lead to the break-up of the present continent assembly.

  19. Optranet: a European project

    NASA Astrophysics Data System (ADS)

    Jeanjean, Marie

    2003-10-01

    In a situation where curricula did not adjust at the required pace and many students are getting attracted out of science and technology, the shortage of skilled workers at the technician and engineer level is known to be a threat to development. In spite of a serious crisis in 2001, the trend of an increased presence of optical technologies remains unchanged and is bound to remain part of the landscape for decades. The level of investment required and the markets make Europe the best scale to plan for unified curricula and a global analysis of the human resources needs. There is no agreement on the definition of a trained optician, and European countries differ in the way they educate opticians, source of a lack of clarity and visibility which is detrimental to attracting good students and to the job market. Through its closely work with companies, OPTRANET will propose measures to enhance the adequacy and the visibility of the training offer.

  20. The European Dimension in Education.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France). Directorate of Education, Culture and Sport, Documentation Section.

    This paper addresses concerns about a European dimension in education that has been created by the enlargement of the European Union (EU) (the inclusion of Austria, Finland, and Sweden) and the gradual transformations of institutions into a future federal state. Sections of the paper include: (1) "Introduction"; (2) "Defining the…

  1. European urology: quality, impact, online.

    PubMed

    Catto, James W F; Montorsi, Francesco; Schulman, Claude

    2013-10-01

    European Urology provides contemporary, cutting-edge urologic research, guidance, and discussion. The journal continues to invite collaborative reviews, to invest in rapid but fair peer review, to seek the best research, and to serve the needs of readers and patients. Copyright © 2013 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  2. The European Dimension in Education.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France). Directorate of Education, Culture and Sport, Documentation Section.

    This paper addresses concerns about a European dimension in education that has been created by the enlargement of the European Union (EU) (the inclusion of Austria, Finland, and Sweden) and the gradual transformations of institutions into a future federal state. Sections of the paper include: (1) "Introduction"; (2) "Defining the…

  3. What Audience for European Television?

    ERIC Educational Resources Information Center

    Wendelbo, Harald Arni

    This discussion of the audience for European television argues that satellite television has taken an upside-down approach, i.e., it has begun by focusing on the hardware, and then the software, before checking to see if there would be a user at the end of the line willing to pay for the whole operation. "European television" is then…

  4. Brazilian Portuguese Ethnonymy and Europeanisms.

    ERIC Educational Resources Information Center

    Stephens, Thomas M.

    1994-01-01

    Delineates the incorporation and analyzes the impact of European borrowings in Brazilian racio-ethnic terminology. This overview covers French, Italian, Spanish, and English influences. Borrowings from European languages have had a small impact on the calculus of Brazilian racio-ethnic terms. (43 references) (Author/CK)

  5. An American Construction of European Education Space

    ERIC Educational Resources Information Center

    Silova, Iveta; Brehm, William C.

    2010-01-01

    The construction of the European education space has typically been attributed to European education policy makers, institutions, and networks. Rarely do scholars consider the role of outside, non-European actors in shaping the terrain of European education thought and practice. This article considers the construction of the European education…

  6. An American Construction of European Education Space

    ERIC Educational Resources Information Center

    Silova, Iveta; Brehm, William C.

    2010-01-01

    The construction of the European education space has typically been attributed to European education policy makers, institutions, and networks. Rarely do scholars consider the role of outside, non-European actors in shaping the terrain of European education thought and practice. This article considers the construction of the European education…

  7. Vascular surgery: the European perspective.

    PubMed

    Harris, P

    1999-09-01

    Isaac Newton, among others, observed that 'we see so far because we are standing upon the shoulders of giants'. In vascular surgery most of the giants have been European, and this is a heritage which we as Europeans can take pride in and build upon if we chose to do so. As in other areas of life, commitment is essential in order to influence the future. For vascular surgeons in Europe this means active participation in the European scientific societies for vascular surgery and in the UEMS. The main value of the EBSQ.VASC assessments to date has been to expose the uneven standards of training in vascular surgery within the European Union. Only if action follows to address these inequalities will the tactics of the European Board of Vascular Surgery be vindicated.

  8. European Citizenship and European Union Expansion: Perspectives on Europeanness and Citizenship Education from Britain and Turkey

    ERIC Educational Resources Information Center

    Wilkins, Chris; Busher, Hugh; Lawson, Tony; Acun, Ismail; Goz, Nur Leman

    2010-01-01

    This article discusses some perspectives on citizenship education in Turkey and Britain in the context of current contested discourses on the nature of European identity and of the European Union (EU). It is based on data collected during an EU-funded student teacher exchange programme between three universities in Turkey and Leicester University…

  9. The European mesothelioma epidemic

    PubMed Central

    Peto, J; Decarli, A; Vecchia, C La; Levi, F; Negri, E

    1999-01-01

    Projections for the period 1995–2029 suggest that the number of men dying from mesothelioma in Western Europe each year will almost double over the next 20 years, from 5000 in 1998 to about 9000 around 2018, and then decline, with a total of about a quarter of a million deaths over the next 35 years. The highest risk will be suffered by men born around 1945–50, of whom about 1 in 150 will die of mesothelioma. Asbestos use in Western Europe remained high until 1980, and substantial quantities are still used in several European countries. These projections are based on the fit of a simple age and birth cohort model to male pleural cancer mortality from 1970 to 1989 for six countries (Britain, France, Germany, Italy, The Netherlands and Switzerland) which together account for three-quarters of the population of Western Europe. The model was tested by comparing observed and predicted numbers of deaths for the period 1990–94. The ratio of mesothelioma to recorded pleural cancer mortality has been 1.6:1 in Britain but was assumed to be 1:1 in other countries. © 1999 Cancer Research Campaign PMID:10027347

  10. Intellectual property and biotechnology: the European debate.

    PubMed

    Brody, Baruch

    2007-06-01

    The European patent system allows for the introduction of moral issues into decisions about the granting of patents. This feature has greatly impacted European debates about the patenting of biotechnology. This essay explores the European experience, in both the European Union and the European Patent Organization. It argues that there has been great confusion surrounding these issues primarily because the Europeans have not developed a general theory about when exclusion from patentability is the best social mechanism for dealing with morally offensive technologies.

  11. A European perspective--the European clinical research infrastructures network.

    PubMed

    Demotes-Mainard, J; Kubiak, C

    2011-11-01

    Evaluating research outcomes requires multinational cooperation in clinical research for optimization of treatment strategies and comparative effectiveness research, leading to evidence-based practice and healthcare cost containment. The European Clinical Research Infrastructures Network (ECRIN) is a distributed ESFRI (European Strategy Forum on Research Infrastructures) roadmap pan-European infrastructure designed to support multinational clinical research, making Europe a single area for clinical studies, taking advantage of its population size to access patients, and unlocking latent scientific potential. Servicing multinational trials started during its preparatory phase, and ECRIN will now apply for an ERIC (European Research Infrastructures Consortium) status by 2011. By creating a single area for clinical research in Europe, this achievement will contribute to the implementation of the Europe flagship initiative 2020 'Innovation Union', whose objectives include defragmentation of the research and education capacity, tackling the major societal challenges starting with the area of healthy ageing, and removing barriers to bring ideas to the market.

  12. North European Transect

    NASA Astrophysics Data System (ADS)

    Korja, Annakaisa; Heikkinen, Pekka J.; Roslov, Yuri; Ivanova, Nina; Verba, Marc; Sakoulina, Tamara

    2010-05-01

    A nearly continuous, 3600 km long, NE-running North European Transect (NET) is combined from the existing deep seismic reflection data sets in the Baltic Sea (BABEL, 1600 km), Northern Finland (FIRE 4-4A, 580 km) and Barents Sea (1-AR, 1440 km;). The reflective image of the deep crust is highly dependent on the thickness of the sedimentary cover. The cover is few hundred meters in the Baltic sea, few tens of meters in the land areas and few kilometers in the Barents Sea area. In the Barents Sea area, the seismic image is dominated by the layered structure of the sedimentary basins and the middle and lower crust are poorly imaged. Therefore the Moho boundary in the Barents Sea has been determined from wide-angle reflections. Geologically the transect covers the transition from Phanerozoic Europe to Precambrian Europe and back to the Phanerozoic Barents Sea Shelf. It displays how Northern Europe grew around Baltica in several tectonic episodes involving the formation and destruction of Columbia/Hudsonland, Rodinia and Pangea supercontinents. The paleo plateboundaries are traversed by subvertical transparent zones suggesting transpressional and trantensional environments. The BABEL lines image how the core of Baltica was formed by sequential accretion of microcontinents and arc terranes at the old continental margin during the Svecofennian Orogeny ~1.9-1.8 Ga .When Baltica joined the Columbia supercontinent, new terranes were added to its southern edge in the Sveocbaltic Orogeny (~1.8 Ga). During the dispersal of the Columbia, the Baltic Sea failed rift was formed, rapakivi granitoids were intruded and sedimentary basins were developed. An extended plate margin structure has been imposed on the Rodinian (Sveconorwegian) and Pangean additions (Variscan-Caledonian). Major crustal thinning takes place along a series of subvertical faults across the Trans-European Suture Zone marking the transition from Phanerozoic to Proterozoic Europe. The FIRE lines in Northen Finland

  13. European MEMS foundries

    NASA Astrophysics Data System (ADS)

    Salomon, Patric R.

    2003-01-01

    According to the latest release of the NEXUS market study, the market for MEMS or Microsystems Technology (MST) is predicted to grow to $68B by the year 2005, with systems containing these components generating even higher revenues and growth. The latest advances in MST/MEMS technology have enabled the design of a new generation of microsystems that are smaller, cheaper, more reliable, and consume less power. These integrated systems bring together numerous analog/mixed signal microelectronics blocks and MEMS functions on a single chip or on two or more chips assembled within an integrated package. In spite of all these advances in technology and manufacturing, a system manufacturer either faces a substantial up-front R&D investment to create his own infrastructure and expertise, or he can use design and foundry services to get the initial product into the marketplace fast and with an affordable investment. Once he has a viable product, he can still think about his own manufacturing efforts and investments to obtain an optimized high volume manufacturing for the specific product. One of the barriers to successful exploitation of MEMS/MST technology has been the lack of access to industrial foundries capable of producing certified microsystems devices in commercial quantities, including packaging and test. This paper discusses Multi-project wafer (MPW) runs, requirements for foundries and gives some examples of foundry business models. Furthermore, this paper will give an overview on MST/MEMS services that are available in Europe, including pure commercial activities, European project activities (e.g. Europractice), and some academic services.

  14. European eye bank association.

    PubMed

    Jones, Gary L A; Ponzin, Diego; Pels, Elisabeth; Maas, Hanneke; Tullo, Andrew B; Claerhout, Ilse

    2009-01-01

    The European Eye Bank Association (EEBA) is a technical-scientific organization for eye banks. Founded in 1989 with the simple objective of sharing information on eye banking, the Association is today the leading pan-national association in Europe dedicated to the advancement of eye banking and an authoritative reference point for eye banks which work according to quality standards. The Association establishes and maintains an agreed set of medical and technical standards, promotes the collection of data on eye bank activities and processes, provides opportunities for the discussion of all aspects of eye banking practice, including eye donor selection and procurement, relevant research and development, education and training in eye banking, and maintains linkage with national and international corneal transplant communities and relevant bodies. The recent introduction of a more structured and focused committee, a permanent secretariat, the development of a website has enabled the Association to establish closer links and collaborative activities with key regulatory bodies and to provide a more constant exchange of clinical, scientific and technical ideas and best practice with fellow professionals by means of its annual meetings, the EEBA directory and website, and a regular newsletter. The EEBA is a scientific organization committed to defining minimum standards and to encouraging eye banks to maintain the highest possible standards for quality and safety. Through its annual meetings, and the collection and exchange of detailed information from member eye banks, the Association can rightly claim to speak with a confident and representative voice on eye banking in Europe. Copyright 2009 S. Karger AG, Basel.

  15. European strategies for mental health.

    PubMed

    Di Fiandra, Teresa

    2009-01-01

    The most recent developments of strategies and policies in the mental health field in Europe are related to the World Health Organization (WHO) Declaration and Action Plan on Mental Health signed by all the Ministers of Health of all Member States in the European Region (2005). The Action Plan proposes ways and means of developing comprehensive mental health policies, listing 12 areas in which challenges are indicated and detailed actions are required. Afterwards the Green Paper on Mental Health has been launched by the European Commission for the definition of an European strategy. The more precise European Pact for Mental Health and Well-being has been presented in 2008. Many other international bodies (OECD, Council of Europe, etc.) have actively worked to stress the mental health issue. All are clearly referring to the Italian model, started 30 years ago.

  16. [European general practice research agenda].

    PubMed

    Mäntyselkä, Pekka; Koskela, Tuomas

    2014-01-01

    The EGPRN (European General Practice Research Network) research agenda is a review compiling the strengths and areas of development of European general practice, based on a systematic literature survey and its versatile analysis. The research agenda is a framework paper sharpening the definition and functions of general practice as well as its significance for researchers and decisionmakers. The agenda is useful in structuring the research, evaluation of research needs, strengthening of infrastructure and strategic planning of new research.

  17. Short- and long-term efficacy of forest thinning to mitigate drought impacts in mountain forests in the European Alps.

    PubMed

    Elkin, Ché; Giuggiola, Arnaud; Rigling, Andreas; Bugmann, Harald

    2015-06-01

    In many regions of the world, drought is projected to increase under climate change, with potential negative consequences for forests and their ecosystem services (ES). Forest thinning has been proposed as a method for at least temporarily mitigating drought impacts, but its general applicability and longer-term impacts are unclear. We use a process-based forest model to upscale experimental data for evaluating the impacts of forest thinning in a drought-susceptible valley in the interior of the European Alps, with the specific aim of assessing (1) when and where thinning may be most effective and (2) the longer-term implications for forest dynamics. Simulations indicate that forests will be impacted by climate-induced increases in drought across a broad elevation range. At lower elevations, where drought is currently prevalent, thinning is projected to temporarily reduce tree mortality, but to have minor impacts on forest dynamics in the longer term. Thinning may be particularly useful at intermediate and higher elevations as a means of temporarily reducing mortality in drought-sensitive species such as Norway spruce and larch, which currently dominate these elevations. However, in the longer term, even intense thinning will likely not be sufficient to prevent a climate change induced dieback of these species, which is projected to occur under even moderate climate change. Thinning is also projected to have the largest impact on long-term forest dynamics at intermediate elevations, with the magnitude of the impact depending on the timing and intensity of thinning. More intense thinning that is done later is projected to more strongly promote a transition to more drought-tolerant species. We conclude that thinning is a viable option for temporarily reducing the negative drought impacts on forests, but that efficient implementation of thinning should be contingent on a site-specific evaluation of the near term risk of significant drought, and how thinning will

  18. European guidance: a project of the European Psychiatric Association.

    PubMed

    Gaebel, W; Möller, H-J

    2012-02-01

    Evidence based medicine is a cornerstone of modern medicine including psychiatry. Treatment practice guidelines are nowadays available for guiding mental health care mainly with a focus on specific disorders. Many important clinical situations or problems beyond treatment, however, are lacking proper guidance. It is in this scope that a European Psychiatry Association (EPA) has developed its own program, the European Guidance Project. The present special issue presents six topics out of these series of guidance documents. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  19. European courts and old people.

    PubMed

    Mulley, Graham P

    2013-09-01

    There are two major European Courts, the European Court of Justice (ECJ) and the European Court of Human Rights (ECHR). The ECJ deals with legal matters, mainly involving the interpretation of EU law and ensuring that the law is applied evenly across all 27 EU member states. The ECHR aims to make certain that civil and political rights of citizens in the 46 member states of the Council of Europe are observed. Most cases involving older citizens are about social policy (such as pension arrangements, equality, age discrimination and mandatory retirement). There have been few cases dealing with patients' rights, long-term care or housing. Referrals of selected cases involving old people should be considered if their rights are not being protected. In this Commentary, there is an account of how these Courts have evolved, together with guidance on whom to refer, to which Court, and when and how referrals should be made.

  20. European core curriculum in neurorehabilitation

    PubMed Central

    Sandrini, Giorgio; Binder, Heinrich; Hömberg, Volker; Saltuari, Leopold; Tarkka, Ina; Smania, Nicola; Corradini, Claudio; Giustini, Alessandro; Kätterer, Christian; Picari, Ledina; Diserens, Karin; Koenig, Eberhard; Geurts, Alexander; Anghelescu, Aurelian; Opara, Józef; Tonin, Paolo; Kwakkel, Gert; Golyk, Volodymyr; Onose, Gelu; Pérennou, Dominique; Picelli, Alessandro

    2017-01-01

    Summary To date, medical education lacks Europe-wide standards on neurorehabilitation. To address this, the European Federation of NeuroRehabilitation Societies (EFNR) here proposes a postgraduate neurorehabilitation training scheme. In particular, the European medical core curriculum in neurorehabilitation should include a two-year residency in a neurorehabilitation setting where trainees can gain practical experience. Furthermore, it should comprise six modules of classroom training organized as weekend seminars or summer/winter schools. In conclusion, after defining the European medical core curriculum in neurorehabilitation, the next activities of the EFNR will be to try and reach the largest possible consensus on its content among all national societies across Europe in order to further validate it and try to extend it to the other, non-medical, professionals on the neurorehabilitation team in line with their core curricula defined by each professional association. PMID:28676138

  1. European Environmental Test Facility Inventory

    NASA Astrophysics Data System (ADS)

    Popovitch, A.

    2004-08-01

    For providing the European industry with a tool enabling to identify and locate suitable test facilities, the ESA will establish and maintain a Web-based European inventory of environmental test facilities. The European Space Agency is operating a Test Centre at ESTEC Noordwijk. It is the unique place in Europe, which is geared to verify very large spacecraft. Environmental testing of systems, subsystems and components can be performed at many places all over Europe. Therefore, the inventory aims at identifying all companies/organizations active in environmental testing and inventorying their facilities as well as their main technical features and capabilities. A questionnaire will be submitted to all companies and organizations active in environmental testing in Europe and willing to appear in this inventory.

  2. European Union a New Babylon?

    NASA Astrophysics Data System (ADS)

    Mesch, F.

    2010-07-01

    The growing European Union faces growing problems in personal communication. These problems cannot be overcome only by more language courses in school. As important is a better mutual knowledge of the culture of other countries, a knowledge that can be gained only by a personal, professional stay in foreign countries. On university level, such stays are best organized by networks connecting European universities. In the broad field of measurement, this IMEKO symposium might offer a unique forum to thoroughly discuss structure and realization of such a network with all interested colleagues.

  3. Interactions between European Citizenship and Language Learning among Adolescent Europeans

    ERIC Educational Resources Information Center

    Hennebry, Mairin

    2011-01-01

    Recent enlargement of the European Union (EU) has created debate as to the suitability of current structures and policies for effectively engaging citizens and developing social cohesion. Education and specifically modern foreign language (MFL) teaching are argued by the literature to play a key role in equipping young people to interact and…

  4. Diagrams of Europeanization: European Education Governance in the Digital Age

    ERIC Educational Resources Information Center

    Decuypere, Mathias

    2016-01-01

    European education governance is increasingly affected by and effectuated through digital means. This article presents an analysis of the way in which Europe is increasingly deploying digital technologies, and more specifically websites, in order to shape and communicate its education policies. Drawing on the notion of the diagram as the…

  5. Interactions between European Citizenship and Language Learning among Adolescent Europeans

    ERIC Educational Resources Information Center

    Hennebry, Mairin

    2011-01-01

    Recent enlargement of the European Union (EU) has created debate as to the suitability of current structures and policies for effectively engaging citizens and developing social cohesion. Education and specifically modern foreign language (MFL) teaching are argued by the literature to play a key role in equipping young people to interact and…

  6. Diagrams of Europeanization: European Education Governance in the Digital Age

    ERIC Educational Resources Information Center

    Decuypere, Mathias

    2016-01-01

    European education governance is increasingly affected by and effectuated through digital means. This article presents an analysis of the way in which Europe is increasingly deploying digital technologies, and more specifically websites, in order to shape and communicate its education policies. Drawing on the notion of the diagram as the…

  7. Impact of climate warming-induced increase in drought stress on successional dynamic of a coniferous forest within a dry inner Alpine environment

    NASA Astrophysics Data System (ADS)

    Schuster, R.; Zeisler, B.; Oberhuber, W.

    2012-04-01

    Climate sensitivity of tree growth will effect the development of forest ecosystems under a warmer and drier climate by changing species composition and inducing shifts in forest distribution. We applied dendroclimatological techniques to determine impact of climate warming on radial stem growth of three native and widespread coniferous tree species of the central Austrian Alps (Norway spruce, Picea abies; European larch, Larix decidua; Scots pine, Pinus sylvestris), which grow intermixed at dry-mesic sites within a dry inner Alpine environment (750 m a.s.l., Tyrol, Austria). Time series of annual increments were developed from > 250 saplings and mature trees. Radial growth response to recent climate warming was explored by means of moving response functions (MRF) and evaluation of trends in basal area increment (BAI) for the period 1911 - 2009. Climate-growth relationships revealed significant differences among species in response to water availability. While precipitation in May - June favoured radial growth of spruce and larch, Scots pine growth mainly depended on April - May precipitation. Spruce growth was most sensitive to May - June temperature (inverse relationship). Although MRF coefficients indicated increasing drought sensitivity of all species, which is most likely related to intensified belowground competition for scarce water with increasing stand density and higher evapotranspiration rates due to climate warming, recent BAI trends strikingly differed among species. While BAI of larch was distinctly declining, spruce showed steadily increasing BAI and quite constant BAI was maintained in drought adapted Scots pine, although at lowest level of all species. Furthermore, more favourable growing conditions of spruce in recent decades are indicated by scattered natural regeneration and higher growth rates of younger trees during first decades of their lifespan. Because human interference and wildlife stock is negligible within the study area, results

  8. Integration through Europeanization: Ukraine’s Policy Towards the European Union

    DTIC Science & Technology

    2012-06-08

    Europeanization . The Orange Revolution of late 2004, and the implementation of the European Neighbourhood Policy , significantly improved Ukraine’s European ...of the European Neighbourhood Policy , significantly improved Ukraine’s European prospects. This thesis examines Ukraine’s efforts to undertake the... Neighbourhood Policy and Ukraine is one of six post-Soviet states invited to cooperate with the European Union within the multilateral

  9. European tests on materials outgassing

    NASA Technical Reports Server (NTRS)

    Zwaal, A.

    1977-01-01

    With a view to international coordination of spacecraft materials, a number of European firms and institutes performed outgassing tests on identical materials at 125 C in high vacuum. The outgassing data obtained with the different types of equipment is presented and both the results and the critical parameters are discussed.

  10. New Superpower, The European Union

    DTIC Science & Technology

    1994-05-01

    196 from Japan and 210 from the EC; in the Super Fifty non-American 27 are from the common market. It is clear that the European Union will be one of...C687e). (page 31, bottom)4 Mastrivh treaty, articulo 6Mastrich treaty, articulo 6Janes 1994, pag 31. 8ii JRATOM and Nuclear Safeguards. Darryl A

  11. European Curricula, Xenophobia and Warfare.

    ERIC Educational Resources Information Center

    Coulby, David

    1997-01-01

    Examines school and university curricula in Europe and the extent of their influence on xenophobia. Considers the pluralistic nature of the European population. Discusses the role of curriculum selection and language policy in state efforts to promote nationalism. Assesses the role of curricular systems in the actual encouragement of warfare,…

  12. Scholarships for European vet students.

    PubMed

    Egan, Jordon; Takacs, Daniella

    2017-02-25

    Every year, students from European vet schools can apply for $5000 scholarships, which aim to 'enhance the academic experience of students'. Among last year's recipients were Jordon Egan, from the Royal Veterinary College, and Daniella Takács, from the University of Veterinary Medicine in Budapest. British Veterinary Association.

  13. Mathematical Modelling in European Education

    ERIC Educational Resources Information Center

    Ferri, Rita Borromeo

    2013-01-01

    Teaching and learning of mathematical modelling has become a key competence within school curricula and educational standards in many countries of the world. The term mathematical modelling, its meaning, and how it can be implemented in mathematics lessons have been intensively discussed during several Conferences of the European Society for…

  14. Reconstructing Indo-European Syllabification

    ERIC Educational Resources Information Center

    Byrd, Andrew Miles

    2010-01-01

    The chief concern of this dissertation is to investigate a fundamental, yet unsolved problem within the phonology of Proto-Indo-European (PIE): the process of syllabification. I show that by analyzing the much more easily reconstructable word-edge clusters we may predict which types of consonant clusters can occur word-medially, provided that we…

  15. Mathematical Modelling in European Education

    ERIC Educational Resources Information Center

    Ferri, Rita Borromeo

    2013-01-01

    Teaching and learning of mathematical modelling has become a key competence within school curricula and educational standards in many countries of the world. The term mathematical modelling, its meaning, and how it can be implemented in mathematics lessons have been intensively discussed during several Conferences of the European Society for…

  16. European perspectives in thoracic surgery

    PubMed Central

    2014-01-01

    Europe, the old Continent, has been the cradle of thoracic surgery from the beginning of the last century. The structure and the activities of the European Society of Thoracic Surgeons (ESTS) activities are directed to enlighten the path, provide the tools and set the standards for a quality inspired practice in thoracic surgery. PMID:24868436

  17. Beyond "Ability": Some European Alternatives

    ERIC Educational Resources Information Center

    Wrigley, Terry

    2013-01-01

    This article draws on European approaches to differentiation that do not entail fatalistic determinism. It describes two challenging initiatives in Denmark, where democratic learning and learning for democracy are enshrined in law. Other examples come from Germany, from the Bielefeld laboratory school and a sixth form college, where planning for…

  18. The European NEO Coordination Centre

    NASA Astrophysics Data System (ADS)

    Perozzi, E.; Borgia, B.; Micheli, M.

    An operational approach to NEO (Near-Earth Object) hazard monitoring has been developed at European level within the framework of the Space Situational Awareness Program (SSA) of the European Space Agency (ESA). Through federating European assets and profiting of the expertise developed in European Universities and Research Centers, it has been possible to start the deployment of the so-called SSA NEO Segment. This initiative aims to provide a significant contribution to the worldwide effort to the discovery, follow-up and characterization of the near-Earth object population. A major achievement has been the inauguration in May 2013 of the ESA NEO Coordination Centre located at ESRIN (Frascati, Italy). The goal of the NEOCC Precursor Service operations is twofold: to make available updated information on the NEO population and the associated hazard and to contribute to optimize the NEO observational efforts. This is done by maintaining and improving a Web Portal publicly available at http://neo.ssa.esa.int and by performing follow-up observations through a network of collaborating telescopes and facilities. An overview of the SSA-NEO System and a summary of the first two years of NEOCC operations is presented.

  19. Attitudes of Europeans toward Age.

    ERIC Educational Resources Information Center

    Ageing International, 1993

    1993-01-01

    Two Commission of European Communities surveys of people over age 15 and of those over 60 demonstrated a widespread belief that older people deserve public support and services and face employment discrimination. Socioeconomic factors influenced older people's sense of security and life satisfaction. Positive intergenerational attitudes appeared.…

  20. European Year of Languages, 2001.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France). Directorate of Education, Culture and Sport, Documentation Section.

    This document is a folder full of brochures describing the activities of Council of Europe and the European Union to celebrate 2001 as a year of languages in order to celebrate the linguistic diversity of Europe and promote the many opportunities available for lifelong language learning. A number of facts and figures about the languages of Europe…

  1. OER: A European Policy Perspective

    ERIC Educational Resources Information Center

    Alquézar Sabadie, Jesús Maria; Castaño Muñoz, Jonatan; Puni, Yves; Redecker, Christine; Vuorikari, Riina

    2014-01-01

    The potential benefits of OER have led many European governments to implement policies supporting their creation and use. This chapter aims to put these OER policies in context, discussing their focus and scope and highlighting challenges and bottlenecks. On the basis of the analysis of the current state of the art, it is argued that one of main…

  2. Reconstructing Indo-European Syllabification

    ERIC Educational Resources Information Center

    Byrd, Andrew Miles

    2010-01-01

    The chief concern of this dissertation is to investigate a fundamental, yet unsolved problem within the phonology of Proto-Indo-European (PIE): the process of syllabification. I show that by analyzing the much more easily reconstructable word-edge clusters we may predict which types of consonant clusters can occur word-medially, provided that we…

  3. The European Location Framework - from National to European

    NASA Astrophysics Data System (ADS)

    Pauknerova, E.; Sidlichovsky, P.; Urbanas, S.; Med, M.

    2016-06-01

    The European Location Framework (ELF) means a technical infrastructure which will deliver authoritative, interoperable geospatial reference data from all over Europe for analysing and understanding information connected to places and features. The ELF has been developed and set up through the ELF Project, which has been realized by a consortium of partners (public, private and academic organisations) since March 2013. Their number increased from thirty to forty in the year 2016, together with a project extension from 36 to 44 months. The project is co-funded by the European Commission's Competitiveness and Innovation Framework Programme (CIP) and will end in October 2016. In broad terms, the ELF Project will deliver a unique gateway to the authoritative reference geospatial information for Europe (harmonised pan-European maps, geographic and land information) sourced from the National Mapping and Cadastral Authorities (NMCAs) around Europe and including transparent licensing. This will be provided as an online ELF web service that will deliver an up-to-date topographic base map and also as view & download services for access to the ELF datasets. To develop and build up the ELF, NMCAs are accompanied and collaborate with several research & academia institutes, a standardisation body, system integrators, software developers and application providers. The harmonisation is in progress developing and triggering a number of geo-tools like edge-matching, generalisation, transformation and others. ELF will provide also some centralised tools like Geo Locator for searching location based on geographical names, addresses and administrative units, and GeoProduct Finder for discovering the available web-services and licensing them. ELF combines national reference geo-information through the ELF platform. ELF web services will be offered to users and application developers through open source (OSKARI) and proprietary (ArcGIS Online) cloud platforms. Recently, 29 NMCAs plus the

  4. European Centre for Disease Prevention and Control.

    PubMed

    Evans, Roger

    2014-11-04

    The European Centre for Disease Prevention and Control was set up in 2005 to strengthen Europe's defences against infectious diseases. The centre is an independent agency of the European Union and is based in Stockholm, Sweden.

  5. New head picked for European Spallation Source

    NASA Astrophysics Data System (ADS)

    Banks, Michael

    2016-06-01

    The UK physicist John Womersley is to become the next director-general of the €1.8bn European Spallation Source (ESS), which is currently being built in Lund, Sweden, by a 17-member consortium of European countries.

  6. European Cargo Ship Launches to Station

    NASA Image and Video Library

    The European Space Agency's third Automated Transfer Vehicle (ATV-3) launched atop an Ariane 5 rocket from the European space port in Kourou, French Guiana, at 12:34 a.m. EDT Friday, beginning a si...

  7. Meeting US and European supplier control requirements.

    PubMed

    Donawa, Maria

    2009-01-01

    Medical device manufacturers operating under European quality system requirements are sometimes surprised to learn that their supplier control procedures do not fully meet United States (US) requirements. This article discusses important differences between US and European requirements for controlling suppliers.

  8. European physics impact - to a first approximation

    NASA Astrophysics Data System (ADS)

    Starckx, Senne

    2013-05-01

    Physics-based industries contributed around 14%, or €3800bn, to the total value of the European economy in 2010 - exceeding that of the construction and retail sectors combined - according to a report by the European Physical Society (EPS).

  9. The Imprimatur of Europe: Turkey, Europeanization, and the European Union

    DTIC Science & Technology

    1994-08-01

    barriers to Turkey’s admission to the ED, the EU’s position on Turkey’s accession, bilateral views of key EU members, and assessment of the likelihood of...circumstances found in the international system. Our purpose is to look carefully at each view with an eye towards assessing its relative ability to contribute...intergovernmental organizations like OPEC, the United Nations, and the European Union, as well as multinational corporations like IBM, Shell or Ford, and

  10. European Security: Chances for a European Defense Entity

    DTIC Science & Technology

    1991-04-12

    terms of a (military) balance between Russia , Germany, Great Britain, France and Austria-Hungary. The balance was not stable as diplomacy...defensie tegen een nieuwe achtergrond," Nederlands instituut voor internationale betrekkingen ’Clingendael,’ November 1990, p. 6, ("The image of threat...implications for Europe as a consequence of the Gulf crisis; o How to cooperate with the East European Nations. See Jan Gerritsen, " Nederland

  11. European psychotraumatology – alongside the recent European history

    PubMed Central

    Lueger-Schuster, Brigitte

    2013-01-01

    This article outlines a personal reflection of experiences within the field of traumatic stress, especially in relation to specific events, which affected the author's professional life. Conclusions for further challenges for European Society for Traumatic Stress Studies (ESTSS) are delineated. ESTSS's role in the global network of traumatic stress societies is discussed. This is a personal view of Brigitte Lueger-Schuster, president of ESTSS on behalf of the 20th birthday of ESTSS. PMID:23755321

  12. The Independent European Force: Costs of Independence

    DTIC Science & Technology

    1993-01-01

    Western European Union (WEU). Advocates of this approach see the European effort as complementary to NATO and oriented toward coalitional activities...Board Spot) Seaport ofdebarkation USAF United States Air Force WEU Western European Union 1.Introduction Background Th amunceoMentAS I in May 1991...Europe-has sparked criticism within Europe. Speaking at a miseting of the Western European Union (WEU), French Foreign Minister Roland Dumnas argued that

  13. ETUDE - European Trade Union Distance Education.

    ERIC Educational Resources Information Center

    Creanor, Linda; Walker, Steve

    2000-01-01

    Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…

  14. Our European Neighbours. Vocational Training No. 2.

    ERIC Educational Resources Information Center

    Vocational Training, 1989

    1989-01-01

    This document addresses vocational training in European countries. The document contains the following articles: (1) "Dear Readers" (Ernst Piehl and Georges Dupont); (2) "Interview with Lord Plumb, President of the European Parliament" (Georges Dupont); "The European Community's 'Ostpolitik'" (Horst G. Krenzler);…

  15. Europeanizing Education: Governing a New Policy Space

    ERIC Educational Resources Information Center

    Lawn, Martin; Grek, Sotiria

    2012-01-01

    The study of common and diverse effects in the field of education across Europe is a growing field of inquiry and research. It is the result of many actions, networks and programmes over the last few decades and the development of common European education policies. "Europeanizing Education" describes the origins of European education…

  16. How Is European Governance Configuring the EHEA?

    ERIC Educational Resources Information Center

    Magalhães, António; Veiga, Amélia; Sousa, Sofia; Ribeiro, Filipa

    2012-01-01

    This article focuses on the interaction between the European dimension driven by the creation of the European Higher Education Area (EHEA) and the development of national reforms to fulfil that objective. On the basis of data gathered in eight countries involved in EuroHESC project TRUE (Transforming European Universities), the curricular and the…

  17. Europeanizing Education: Governing a New Policy Space

    ERIC Educational Resources Information Center

    Lawn, Martin; Grek, Sotiria

    2012-01-01

    The study of common and diverse effects in the field of education across Europe is a growing field of inquiry and research. It is the result of many actions, networks and programmes over the last few decades and the development of common European education policies. "Europeanizing Education" describes the origins of European education…

  18. European Initiatives in Postgraduate Education in Gerontology

    ERIC Educational Resources Information Center

    van Rijsselt, Rene J. T.; Parkatti, Terttu; Troisi, Joseph

    2007-01-01

    This paper describes three innovative European initiatives in postgraduate education in gerontology. The first is the European Masters Program in Gerontology (EuMaG), developed as an interdisciplinary joint program, supported and delivered by 22 European universities. Second, the Nordplus initiative to increase mobility of students and staff in…

  19. European Initiatives in Postgraduate Education in Gerontology

    ERIC Educational Resources Information Center

    van Rijsselt, Rene J. T.; Parkatti, Terttu; Troisi, Joseph

    2007-01-01

    This paper describes three innovative European initiatives in postgraduate education in gerontology. The first is the European Masters Program in Gerontology (EuMaG), developed as an interdisciplinary joint program, supported and delivered by 22 European universities. Second, the Nordplus initiative to increase mobility of students and staff in…

  20. How Is European Governance Configuring the EHEA?

    ERIC Educational Resources Information Center

    Magalhães, António; Veiga, Amélia; Sousa, Sofia; Ribeiro, Filipa

    2012-01-01

    This article focuses on the interaction between the European dimension driven by the creation of the European Higher Education Area (EHEA) and the development of national reforms to fulfil that objective. On the basis of data gathered in eight countries involved in EuroHESC project TRUE (Transforming European Universities), the curricular and the…

  1. First-Ever European Space Weather Week

    NASA Astrophysics Data System (ADS)

    Simpson, Sarah

    2004-07-01

    Europe's first Space Weather Week is scheduled to take place at the European Space Agency's European Space Research and Technology Centre (ESTEC) in Noordwijk, The Netherlands, for five days beginning 29 November. Modeled after the U.S. Space Weather Week, the European agenda will highlight not only services and applications but also the crucial activity of transitioning scientific discoveries into forecasting capabilities.

  2. Making Citizens, Being European? European Symbolism in Slovenian Citizenship Education Textbooks

    ERIC Educational Resources Information Center

    Banjac, Marinko; Pušnik, Tomaž

    2015-01-01

    Citizenship education has been an important part of the European Union's (EU) agenda to integrate a European dimension into schools' curricula. The usage of European symbolism in citizenship education curriculum material has been an especially important (yet understudied) means not only to promote a distinct European identity and increase…

  3. Making Citizens, Being European? European Symbolism in Slovenian Citizenship Education Textbooks

    ERIC Educational Resources Information Center

    Banjac, Marinko; Pušnik, Tomaž

    2015-01-01

    Citizenship education has been an important part of the European Union's (EU) agenda to integrate a European dimension into schools' curricula. The usage of European symbolism in citizenship education curriculum material has been an especially important (yet understudied) means not only to promote a distinct European identity and increase…

  4. Traceability from a European perspective.

    PubMed

    Schwägele, F

    2005-09-01

    At pan-European level there is a need for traceability systems giving information on origin, processing, retailing and final destination of foodstuffs. Such systems shall enhance consumer confidence in food; enable the regulatory authorities to identify and to withdraw health hazardous and non-consumable foodstuffs from the market. Animal feeds are an element in this "food-to-farm" approach to public health. Such feedstuffs are preliminary elements of some foods for human consumption, and hence are an inherent element of the food chain. A harmonised pan-European food traceability protocol would greatly assist authorities in detecting fraud as well as dangerous substances. The food chain comprises a range of sequential and parallel stages bridging the full spectrum from agricultural production to the consumable foodstuffs by consumers. EU legislation on traceability and the technologies needed to implement this system for meat and meat products are the focus of this paper.

  5. Integrating the European Securities Settlement

    NASA Astrophysics Data System (ADS)

    Schaper, Torsten

    The cross-border securities settlement in Europe is still said to be highly inefficient. One main reason can be seen in technical barriers between the different domestic settlement systems. Beside efforts to implement industry-specific communication standards an integration of the different settlement systems is necessary. The CSD-link model, the hub and spokes model, and the European CSD model aim to integrate European securities settlement. They have in common that they address the problem of interlinkage of national Central Securities Depositories and differ essentially in the way of achieving integration. These models are evaluated from a macro-economic perspective considering transaction costs, risks, and the integration of the cross-border securities settlement process.

  6. Carbon accumulation in European forests

    NASA Astrophysics Data System (ADS)

    Ciais, P.; Schelhaas, M. J.; Zaehle, S.; Piao, S. L.; Cescatti, A.; Liski, J.; Luyssaert, S.; Le-Maire, G.; Schulze, E.-D.; Bouriaud, O.; Freibauer, A.; Valentini, R.; Nabuurs, G. J.

    2008-07-01

    European forests are intensively exploited for wood products, yet they also form a sink for carbon. European forest inventories, available for the past 50 years, can be combined with timber harvest statistics to assess changes in this carbon sink. Analysis of these data sets between 1950 and 2000 from the EU-15 countries excluding Luxembourg, plus Norway and Switzerland, reveals that there is a tight relationship between increases in forest biomass and forest ecosystem productivity but timber harvests grew more slowly. Encouragingly, the environmental conditions in combination with the type of silviculture that has been developed over the past 50 years can efficiently sequester carbon on timescales of decades, while maintaining forests that meet the demand for wood. However, a return to using wood as biofuel and hence shorter rotations in forestry could cancel out the benefits of carbon storage over the past five decades.

  7. A Larch Specification of Copying Garbage Collection

    DTIC Science & Technology

    1992-12-01

    unvisited node, and forms the head of the queue. Because of the use of unscanned and scanned pointers, CGC terminology generally uses the term unscanned for...they are obvious but long and tedious. void gc(void) { forwazdloota(o; scanUnscannedo; To show that gc satisfies its specification (figure 6) the...changing the basic algorithm, as long as forwardaddr can ignore already forwarded references. This is why forwardAddr is specified so that it can

  8. Preliminary Report on the Larch Shared Language.

    DTIC Science & Technology

    1983-10-01

    and Goguen 771 R.M. Burstall and JA. Goguen, "Putting Theories Together to Make Specifications," Proc. 5th International Joint Conference on Artiicial ... Intelligence , Cambridge, MA, 1977, 1045-1058. [Butall and Goguen 811 R.M. Burstall and JA. Goguen, "An Informal Introduction to Specifications Using

  9. European Science Notes Information Bulletin.

    DTIC Science & Technology

    1992-12-01

    Third European Conference on Diamond, Diamond-like, and Related Coatings .................. 427 M. N. Yoder, L. Kabacoff, J. E. Butler, K Doverspike, J...tions on the functionf will yield results on the the correlation E(dj[n], dk[m]) depends on H, j, k , analysis and synthesis operators. m, n and the number...structure of fully developed turbulence in the ho- goes like this: Define the functions ,•j..(x) = j , k (x) mogeneous and inhomogeneous, incompressible

  10. Evaluating the European Defense Force

    DTIC Science & Technology

    2002-05-31

    Union and the European Security and Defense Identity. From its inception following World War II, the WEU has shared a common birthright of sorts...for a merging of monetary, citizenship , and security affairs. The monetary policy is already in effect with the new Euro dollar entering...circulation in 2002. The most dramatic impact of citizenship policies is the idea of dual- citizenship of Europe and its respective states members. Finally

  11. European Union: US Hegemonic Competitor

    DTIC Science & Technology

    2001-12-01

    and the United Arab Emirates , Iraq (1997), and Iran (1997). 413 Haass, p. 236. 124 efforts at fighting domestic leftist uprisings.”414 Although...farreaching consequences for Arab willingness to work with the United States against Iraq and Libya, as well as its affects on European views towards...Number Grant Number Program Element Number Author(s) Kellar, Ronald Project Number Task Number Work Unit Number Performing Organization Name(s

  12. European Seminar on Neural Computing

    DTIC Science & Technology

    1988-08-31

    weights) There are three distinct approaches currently being of the connections between PE’s, analogous to synaptic taken for supporting neural ...for creation of dedicated re- * Connectionist models for artificial intelligence (Al) search centers, analogous to the Computer and Neural System...IONDOIL ONRL Report 8 Oo Ln 0In t m S D TIC European Seminar on Neural Computing 1 IELECTE is MAY 161990 L D % Claire Zomzely-Neurath 31 August 1988

  13. The European Board of Orthodontists.

    PubMed

    Cozzani, Mauro; Weiland, Frank

    2016-06-01

    The multiplicity of nations, languages and differing ways and levels of specialized orthodontic education in Europe lead to the need for an objective review of the quality of orthodontic care. To this purpose, The European Board of Orthodontists (EBO) was introduced. This article gives an overview of the objectives of the EBO, its development and the requirements for membership. Copyright © 2016 CEO. Published by Elsevier Masson SAS. All rights reserved.

  14. EST: The European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Collados, M.

    2008-09-01

    The European Solar Telescope (EST) is a project for a 4 meter-class ground-based telescope, to be located in the Canary Islands. The project is promoted by the European Association for Solar Telescopes (EAST), a consortium formed by research organizations from 15 European countries. EST will be optimized for studies of magnetic coupling between the deep photosphere and upper chromosphere. The project has been approved for funds by the European Union, within the FP-7 framework, to produce the design of all systems and subsystems of the telescope during the next three years. This includes the optical and optomechanical design of the telescope itself and of the instruments and their control. MCAO will be included in the optical path in a natural way to compensate for atmospheric disturbances in an optimum way. The design of EST will strongly emphasize the use of a large number of visible and near-infrared instruments simultaneously which will influence the telescope design from the very beginning. This communication will center mainly on the scientific objectives that EST will address. Generally speaking, they involve understanding how the magnetic field emerges through the solar surface, interacts with the plasma dynamics to transfer energy between different regions, and finally releases it in the form of heat or as violent events in the solar chromosphere and corona. Among the many topics of interest, one may cite, as described in the EST Science Requirements Document: small-scale flux emergence in quiet sun regions, large-scale magnetic structures, magnetic flux cancellation processes, polar magnetic fields, magnetic topology of the photosphere and chromosphere, conversion of mechanical to magnetic energy in the photosphere, wave propagation from photosphere to chromosphere, energy dissipation in the chromosphere at small and large scales, etc. The present status and future perspectives of the project will also be outlined.

  15. European Space Software Repository ESSR

    NASA Astrophysics Data System (ADS)

    Livschitz, Jakob; Blommestijn, Robert

    2016-08-01

    The paper and presentation will present the status of the ESSR (European Space Software Repository), see [1]. It will describe the development phases, outline the web portal functionality and explain the process steps behind. Not only the front-end but also the back-end will be discussed.The ESSR web portal went live ESA internal on May 15th, 2015 and live world-wide September 19th, 2015. Currently the ESSR is in operations.

  16. Brain death: the European perspective.

    PubMed

    Citerio, Giuseppe; Murphy, Paul G

    2015-04-01

    Some of the seminal steps toward the recognition and definition of brain death were European. There is a general consensus on both the medical concept of brain death in Europe as well as the minimum fundamental clinical standards that are required for its diagnosis-the absence of consciousness, brainstem reflexes, and the ability to breathe in the absence of reversible or confounding conditions. Two aspects of brain death determination are addressed in this article. The authors analyze how brain death is diagnosed across Europe, identifying both the similarities and differences that exist between countries (the latter mainly concerning ancillary tests, timing, and the number of physicians involved in the brain death determination). In addition, they describe the very considerable variations in when brain death determinations are made between and within individual European countries, and propose that they are due to differences in the end-of-life care practices in patients with irreversible brain injuries, medical attitudes, and organ donation practices. Although legislation is available to standardize the brain death diagnosis process in most individual European countries, there are still disparities across Europe as a whole. The current variation in practice makes a continental consensus for the definition of brain death imperative.

  17. International Heliophysical Year: European Activities

    NASA Astrophysics Data System (ADS)

    Briand, C.

    2007-08-01

    The First European General Assembly of the "International Heliophysical Year" (IHY) took place at the headquarters of the Centre Nationial de la Recherche Scientifique (CNRS) in Paris, France, 10-13 January 2006. There were 113 participants representing 27 nations. The science concerned with the International Heliophysical Year programme was first illustrated. Then, the status of current instruments as well as practical information on the campaign management policy was given. Twenty European National Coordinators described the progress of their IHY activities. Representatives from Egypt, Angola and the coordinator of the Balkan, Black and Caspian Sea Region also reported on the progress of IHY activities in their respective regions. People from the IHY Secretariat provided a summary of the global IHY efforts including the United Nations Basic Space Sciences Program. In the education and public outreach front, a variety of activities have been planned: TV and radio shows, board games on space weather, specific programmes for schools and universities, workshops for teachers are some of the actions that were presented by the delegates. Beyond of these national and individual initiatives, specific activities requiring European coordination were discussed. This paper provides an extended summary of the main talks and discussions that held during the meeting.

  18. [European perspectives of health telematics].

    PubMed

    Rienhoff, O; Verhey, J

    2005-06-01

    The European perspectives of the present German developments in the field of health telematics are discussed critically. It is pointed out that technical projects have been financed with considerable means in the EU, however with out having any lasting effect on the value of health telematics in the health systems of Europe. A decisive cause is that the "health" topic was not codified in the Roman contracts. The international, global market is a crucial factor for international development and thus also for the orientation of the German projects and their economical and political success. The USA plays a dominant role on the global market. Caused by different reasons a corresponding market potential in the EU cannot be expected in the foreseeable future. With regard to the new options provided by telematics, it is therefore recommended that the national health services be reorganized, thus increasing quality and efficiency. With regard to progressively individualized medical care, the subject of "health" should afterwards be included in the European contracts. In the long run, an adjustment of the systems and uniform use of telematics could be achieved. Till then the coordination between the national governments in the area of health politics is seen as the most effective means for European integration.

  19. Third European Stroke Science Workshop.

    PubMed

    Dichgans, Martin; Planas, Anna M; Biessels, Geert Jan; van der Worp, Bart; Sudlow, Cathie; Norrving, Bo; Lees, Kennedy; Mattle, Heinrich P

    2016-07-01

    Lake Eibsee, Garmisch-Partenkirchen, November 19 to 21, 2015: The European Stroke Organization convened >120 stroke experts from 27 countries to discuss latest results and hot topics in clinical, translational, and basic stroke research. Since its inception in 2011, the European Stroke Science Workshop has become a cornerstone of European Stroke Organization's academic activities and major highlight for researchers in the field. Participants include stroke researchers at all career stages who convene for plenary lectures and discussions, thus facilitating crosstalk among researchers from different fields. As in previous years, the workshop was organized into 7 scientific sessions each focusing on a major research topic. All sessions started with a keynote lecture that provided an overview on current developments and set the scene for the following presentations. The latter were short focused talks on a timely topic and included the most recent findings, including unpublished data. A new element at this year's meeting was a hot topic session in which speakers had to present a provocative concept or update sharply within 5 minutes. In the following, we summarize the key contents of the meeting. The program is provided in the online-only Data Supplement. © 2016 American Heart Association, Inc.

  20. Progress in European CELSS activities

    NASA Technical Reports Server (NTRS)

    Skoog, A. I.

    1987-01-01

    The European Controlled Ecological Life Support System (CELSS) activities started in the late 1970's with system analysis and feasibility studies of Biological Life Support Systems (BLSS). The initiation for CELSS came from the industry side in Europe, but since then planning and hardware feasibility analyses have been initiated also from customer/agency side. Despite this, it is still too early to state that a CELSS program as a concerted effort has been agreed upon in Europe. However, the general CELSS objectives were accepted as planning and possible development goals for the European effort for manned space activities, and as experimental planning topics in the life sciences community for the next decades. It is expected that ecological life support systems can be tested and implemented on a space station towards the end of this century or early in the next. For the European activities a possible scenario can be projected based on ongoing life support system development activities and the present life sciences goals.

  1. 7 CFR 301.91-5 - Issuance and cancellation of certificates and limited permits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... prevent the spread of European larch canker; and 3 An inspector may hold, seize, quarantine, treat, apply... in each case, it is determined that such movement will not result in the spread of European larch canker because the disease will be destroyed by such specified handling, utilization, or processing; (2...

  2. 7 CFR 301.91-1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... European larch canker. The plant disease known as European larch canker, Lachnellula willkommi (Dasycypha... Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE... agreement between Plant Protection and Quarantine and a person engaged in the business of growing, handling...

  3. 7 CFR 301.91-1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... European larch canker. The plant disease known as European larch canker, Lachnellula willkommi (Dasycypha... Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE... agreement between Plant Protection and Quarantine and a person engaged in the business of growing, handling...

  4. European initiatives in postgraduate education in gerontology.

    PubMed

    van Rijsselt, René J T; Parkatti, Terttu; Troisi, Joseph

    2007-01-01

    This paper describes three innovative European initiatives in postgraduate education in gerontology. The first is the European Masters Program in Gerontology (EuMaG), developed as an interdisciplinary joint program, supported and delivered by 22 European universities. Second, the Nordplus initiative to increase mobility of students and staff in the field of gerontology in the European Nordic countries is elaborated. Third, two postgraduate Gerontology and Geriatrics programs offered by the European Centre of Gerontology and Geriatrics, University of Malta are presented. In 1995, the Centre was designated a WHO Collaborating Centre for healthy aging. To provide a context for these initiatives, a short overview is presented of developments in the European Higher Education Area, and the current state and recent developments in gerontology training in Europe is elaborated. The article concludes with discussion of the feasibility and sustainability of European internationalization efforts in education and training in gerontology.

  5. Sunglasses, the European directive and the European standard.

    PubMed

    Dain, Stephen John; Ngo, Thi Phuong Thao; Cheng, Brian Barry; Hu, Angel; Teh, Adrian Ghim Boon; Tseng, Jane; Vu, Nam

    2010-05-01

    The Optics and Radiometry Laboratory (ORLAB) provides a testing service for the Australian sunglass industry to assist its compliance with the mandatory Consumer Product Safety Standard. In doing so, a number of sunglasses carrying the CE mark (in effect a claim of compliance with the European Union Personal Protective Equipment Directive) have been tested. Since there is no mandatory testing in Europe (the sunglass industry is deemed self regulating), evaluating their performance will give an insight into compliance with the Directive. Consecutive submissions to ORLAB over a period of 18 months were examined for CE marked sunglasses. The results for 646 CE marked pairs of sunglasses tested during 2003 and first half 2004 were examined and evaluated for compliance with EN 1836 (the European sunglass standard) on the basis of refractive power, prismatic power, transmittance (visible, UV and coloration) and polarization. A total of 17.3% failed EN 1836 and 3.3% were borderline (i.e. within our uncertainties of measurement of the requirement). The failures comprised: 0.9% lens defect; 12.5% polarization alignment error; 2.7% excessive vertical prism; 22.3% excessive horizontal prism; 27.7% excessive spherical power; 14.3% excessive cylindrical power; 1.8% excessive UV transmittance; and 23.2% transmittance difference between lenses (always gradient tints). With up to 20% non-compliance, self regulation is not working particularly well in providing the public with complying sunglasses.

  6. European alchemy: some traditional beliefs.

    PubMed

    Karpenko, V

    1999-01-01

    Three important doctrines of European alchemy are discussed: the Emerald Table of Hermes, the idea of transmutation, and the Elixir of Life. The analysis of these problems is focused on the 16th century, the epoch of the high flourish of alchemy in Renaissance Europe. As typical examples two works are chosen: the treatises of Jean-Pierre Fabre (1588-1658) and Alexander von Suchten (? 1520 - ? 1590). The arguments of these authors illustrate the ways how alchemists tried to defend their position in face of repeated failures. Just the 16th century stood in the sign of dramatic development of crafts, but, simultaneously, of growing interest in alchemy.

  7. European Nucleotide Archive in 2016

    PubMed Central

    Toribio, Ana Luisa; Alako, Blaise; Amid, Clara; Cerdeño-Tarrága, Ana; Clarke, Laura; Cleland, Iain; Fairley, Susan; Gibson, Richard; Goodgame, Neil; ten Hoopen, Petra; Jayathilaka, Suran; Kay, Simon; Leinonen, Rasko; Liu, Xin; Martínez-Villacorta, Josué; Pakseresht, Nima; Rajan, Jeena; Reddy, Kethi; Rosello, Marc; Silvester, Nicole; Smirnov, Dmitriy; Vaughan, Daniel; Zalunin, Vadim; Cochrane, Guy

    2017-01-01

    The European Nucleotide Archive (ENA; http://www.ebi.ac.uk/ena) offers a rich platform for data sharing, publishing and archiving and a globally comprehensive data set for onward use by the scientific community. With a broad scope spanning raw sequencing reads, genome assemblies and functional annotation, the resource provides extensive data submission, search and download facilities across web and programmatic interfaces. Here, we outline ENA content and major access modalities, highlight major developments in 2016 and outline a number of examples of data reuse from ENA. PMID:27899630

  8. European perspectives of food safety.

    PubMed

    Bánáti, Diána

    2014-08-01

    Food safety has been a growing concern among European Union (EU) citizens over the last decades. Despite the fact that food has never been safer, consumers are considerably uncertain and increasingly critical about the safety of their food. The introduction of new principles, such as the primary responsibility of producers, traceability, risk analysis, the separation of risk assessment and risk management provided a more transparent, science-based system in Europe, which can help to restore consumers' lost confidence. The present EU integrated approach to food safety 'from farm to fork' aims to assure a high level of food safety within the EU.

  9. Pharmaceutical policies in European countries.

    PubMed

    Barros, Pedro Pita

    2010-01-01

    Pharmaceutical expenditures have an important role in Europe. The attempts to control expenditure have used a wide range of policy measures. We reviewed the main measures adopted by the European Union countries, especially in countries where governments are the largest third-party payers. To complement a literature review on the topic, data was gathered from national reviews of health systems and direct inquiries to several government bodies. Almost all countries regulate prices of pharmaceutical products. Popular policy measures include international referencing to set prices (using as benchmark countries that have set lower prices), internal reference pricing systems to promote price competition in domestic markets, and positive lists for reimbursement to promote consumption of generics (including in some cases substitution by pharmacists of drugs prescribed by physicians). Despite the wide range of policy measures, it is not possible to identify a "silver bullet" to control pharmaceutical expenditures. We also identified two main policy challenges: policy coordination among countries within the European Union to maintain incentives for R&D at the global level, and the development of new relationships with the pharmaceutical industry; namely, the so-called risk-sharing agreements between the pharmaceutical industry and governments/regulators (or large third-party payers).

  10. European EVA decompression sickness risks

    NASA Astrophysics Data System (ADS)

    Vogt, Lorenz; Wenzel, Jürgen; Skoog, A. I.; Luck, S.; Svensson, Bengt

    For the first manned flight of Hermes there will be a capability of performing EVA. The European EVA Space Suit will be an anthropomorphic system with an internal pressure of 500 hPa of pure oxygen. The pressure reduction from the Hermes cabin pressure of 1013 hPa will induce a risk for Decompression Sickness (DCS) for the EVA crewmember if no adequate protective procedures are implemented. Specific decompression procedures have to be developed. From a critical review of the literature and by using knowledge gained from research conducted in the past in the fields of diving and aerospace medicine safe protective procedures are proposed for the European EVA scenario. An R factor of 1.2 and a tissue half-time ( t1/2) of 360 minutes in a single-tissue model have been identified as appropriate operational values. On the basis of an acceptable risk level of approximately 1%, oxygen prebreathing times are proposed for (a) direct pressure reduction from 1013 hPa to a suit pressure of 500 hPa, and (b) staged decompression using a 700 hPa intermediate stage in the spacecraft cabin. In addition, factors which influence individual susceptibility to DCS are identified. Recommendations are also given in the areas of crew selection and medical monitoring requirements together with therapeutic measures that can be implemented in the Hermes scenario. A method for demonstration of the validity of proposed risks and procedures is proposed.

  11. Policymaking in European healthy cities.

    PubMed

    de Leeuw, Evelyne; Green, Geoff; Spanswick, Lucy; Palmer, Nicola

    2015-06-01

    This paper assesses policy development in, with and for Healthy Cities in the European Region of the World Health Organization. Materials for the assessment were sourced through case studies, a questionnaire and statistical databases. They were compiled in a realist synthesis methodology, applying theory-based evaluation principles. Non-response analyses were applied to ascertain the degree of representatives of the high response rates for the entire network of Healthy Cities in Europe. Further measures of reliability and validity were applied, and it was found that our material was indicative of the entire network. European Healthy Cities are successful in developing local health policy across many sectors within and outside government. They were also successful in addressing 'wicked' problems around equity, governance and participation in themes such as Healthy Urban Planning. It appears that strong local leadership for policy change is driven by international collaboration and the stewardship of the World Health Organization. The processes enacted by WHO, structuring membership of the Healthy City Network (designation) and the guidance on particular themes, are identified as being important for the success of local policy development. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Sprawl in European urban areas

    NASA Astrophysics Data System (ADS)

    Prastacos, Poulicos; Lagarias, Apostolos

    2016-08-01

    In this paper the 2006 edition of the Urban Atlas database is used to tabulate areas of low development density, usually referred to as "sprawl", for many European cities. The Urban Atlas database contains information on the land use distribution in the 305 largest European cities. Twenty different land use types are recognized, with six of them representing urban fabric. Urban fabric classes are residential areas differentiated by the density of development, which is measured by the sealing degree parameter that ranges from 0% to 100% (non-developed, fully developed). Analysis is performed on the distribution of the middle to low density areas defined as those with sealing degree less than 50%. Seven different country groups in which urban areas have similar sprawl characteristics are identified and some key characteristics of sprawl are discussed. Population of an urban area is another parameter considered in the analysis. Two spatial metrics, average patch size and mean distance to the nearest neighboring patch of the same class, are used to describe proximity/separation characteristics of sprawl in the urban areas of the seven groups.

  13. The European-American exchange.

    PubMed

    Guerra, F

    1993-01-01

    The European-American exchange of infectious diseases was responsible for the demographic havoc of the native population in the New World after 1492. Prior to this date medical writers describe the presence in Spain of viral diseases like influenza, parotitis, smallpox, measles, poliomyelitis, and rabies; there were also rickettsiasis, diphtheria, salmonellosis, plague, tubercolosis, leprosy, malaria, scabies and tinea. In America, before European arrivals, there were no records of human viral diseases, though there were records of rickettsiasis, treponematosis--pinta, yaws and syphilis--leihsmaniasis, amibiasis and perhaps leprosy. With the discovery of America in 1492, Columbus's sailors were contaminated by yaws and spread this disease into Europe. In 1493 influenza, as a zoonosis, was introduced into Santo Domingo and was responsible for the annihilation of the natives of the Antilles in less than a quarter of a century; in 1518 smallpox was also introduced in Santo Domingo and then to the American continent by negro slaves: by the same means measles were introduced in 1531. The previous existence or introduction of other infectious diseases in America is also discussed.

  14. Changes in European spring phenology

    NASA Astrophysics Data System (ADS)

    Ahas, R.; Aasa, A.; Menzel, A.; Fedotova, V. G.; Scheifinger, H.

    2002-11-01

    The European phyto-phenological database of the EU 5th Framework project POSITIVE facilitated an examination of the rate and spatial pattern of changes in spring phenology across Europe. This database was collected, evaluated and composed from different national databases of Eastern and Western Europe covering the time period 1951-1998. Results show that spring phases have advanced four weeks in Western and Central Europe, and have been delayed up to two weeks in Eastern Europe. Western European spring starts earlier because of the intensive flow of warmer Atlantic air masses; the Eastern part of Europe has a different phenological rhythm and trends, that can be explained by the influence of the Siberian high. The highest rate of significant (p < 0.05) phenological change (-0.3 to -0.4 days per year) occurs in the Western Europe and Baltic Sea regions for early spring phases of hazel and colts-foot. Spring phases of birch, apple and lilac, and summer phases, such as the flowering of linden, tend to occur earlier with an average rate of -0.1 to 0.3 days per year.

  15. ALARA in European nuclear installations

    SciTech Connect

    Lefaure, C.; Croft, J.; Pfeffer, W.; Zeevaert, T.

    1995-03-01

    For over a decade the Commission of the European Community has sponsored research projects on the development and practical implementation of the Optimization principle, or as it is often referred to, ALARA. These projects have given rise to a series of successful international Optimization training courses and have provided a significant input to the periodic European Seminars on Optimization, the last one of which took place in April 1993. This paper reviews the approaches to Optimization that have development within Europe and describes the areas of work in the current project. The on-going CEC research project addresses the problem of ALARA and internal exposures, and tries to define procedures for ALARA implementation, taking account of the perception of the hazard as well as the levels of probability of exposure. The relationships between ALARA and work management, and ALARA and decommissioning of installations appear to be other fruitful research areas. Finally, this paper introduces some software for using ALARA decision aiding techniques and databases containing feed back experience developed in Europe.

  16. The new European Hubble archive

    NASA Astrophysics Data System (ADS)

    De Marchi, Guido; Arevalo, Maria; Merin, Bruno

    2016-01-01

    The European Hubble Archive (hereafter eHST), hosted at ESA's European Space Astronomy Centre, has been released for public use in October 2015. The eHST is now fully integrated with the other ESA science archives to ensure long-term preservation of the Hubble data, consisting of more than 1 million observations from 10 different scientific instruments. The public HST data, the Hubble Legacy Archive, and the high-level science data products are now all available to scientists through a single, carefully designed and user friendly web interface. In this talk, I will show how the the eHST can help boost archival research, including how to search on sources in the field of view thanks to precise footprints projected onto the sky, how to obtain enhanced previews of imaging data and interactive spectral plots, and how to directly link observations with already published papers. To maximise the scientific exploitation of Hubble's data, the eHST offers connectivity to virtual observatory tools, easily integrates with the recently released Hubble Source Catalog, and is fully accessible through ESA's archives multi-mission interface.

  17. The European LGS test facility

    NASA Astrophysics Data System (ADS)

    Myers, R. M.; Bonaccini Calia, D.; Devaney, N.; Esposito, S.; Goodsell, S. J.; Goncharov, A.; Guerra, J. C.; Guillet de Chatellus, H.; Harrison, M. A.; Holzloehner, R.; Marchetti, E.; Morris, T. J.; Pinna, E.; Pique, J.-P.; Rabien, S.; Reyes, M.; Ribak, E.; Rutten, R. G. M.; Schnetler, H.; Strachan, M.; Stuik, R.; Talbot, R. G.; Tulloch, S. M.

    2007-09-01

    A European Laser Guide Star (LGS) test facility is proposed for the 4.2m William Herschel Telescope (WHT) on La Palma. It will test the next-generation Adaptive Optics (AO) LGS technologies to aid risk mitigation of Extremely Large Telescope (ELT) LGS AO systems. In particular, critical scaling of current LGS AO technologies to ELT dimensions will be tested. For example, experiments addressing increased spot elongation, cone effect and the order of correction required. A pan-European consortium proposes to construct test facility infrastructure on the WHT for a number of risk mitigating experiments. The infrastructure includes the construction of a Nasmyth platform based controlled environment 'Ground-based Adaptive optics Innovative Laboratory' (GRAIL), an experimental test environment 'Testbed integration facility' (TIF) and some common-experiment equipment such as the Common Re-Imaging AO System. Experiments that are proposed for this facility cover the areas of laser technologies, spot elongation, LGS wavefront sensing, parallel launch concepts, Multi-Object AO, atmospheric characterisation, co-phasing and real-time control system risk mitigation.

  18. Eddy covariance measurements of annual carbon dioxide exchange in two natural ecosystems of the northwestern Italian Alps

    NASA Astrophysics Data System (ADS)

    Galvagno, Marta; Migliavacca, Mirco; Cremonese, Edoardo; Busetto, Lorenzo; Cogliati, Sergio; Colombo, Roberto; Manca, Giovanni; Meroni, Michele; Morra di Cella, Umberto; Rossini, Micol

    2010-05-01

    In consequence of the relationship between climate change and atmospheric greenhouse gases concentrations, a prime issue of recent researches is the quantification of the carbon balance of terrestrial biomes. In the last decades an increasing number of monitoring sites has recently been implemented worldwide, with the aim to better understand and quantify how inter-annual climate fluctuations affect net carbon exchange and the length of growing season over different vegetation types, land uses and climates. Eddy covariance (EC) technique is a widespread method that provide a direct measure of net carbon dioxide exchange across the biosphere-atmosphere interface by measuring the covariance between fluctuations in vertical wind velocity and CO2 mixing ratio. Two long-term monitoring sites have been equipped in the northwest Italian Alps (Aosta Valley) with the aim of quantify the annual carbon dioxide sequestration by grassland and forest ecosystems in relation to climate change. Grasslands and European larch forests (Larix decidua, Mill.) are the most representative vegetation types of this alpine region. The grassland site, located at an elevation of 2160 m asl, has been equipped in summer 2008 in an abandoned pasture with Nardus stricta as dominant species. European larch stand is located at 2050 m asl, at a distance of ~8 km from the grassland, and measurements has started in winter 2009. Both sites have been equipped with the same eddy flux system mounted at 2.5 m and 20 m above the ground in the grassland and in the larch forest, respectively. Both sites were equipped with a basic EC system: a3D sonic anemometer and an open-path infrared gas analyser (LI-7500, LICOR Inc.). Along EC the main meteorological variables are measured (e.g. air temperature, humidity, precipitation, photosynthetically active radiation, PAR, , soil water content, snow height etc..). In order to link annual sites productivity to the growing seasons length, phenological observations are

  19. The New European Wind Atlas

    NASA Astrophysics Data System (ADS)

    Lundtang Petersen, Erik

    2013-04-01

    The New European Wind Atlas 1. European wind resource assessment through a ERA-NET Plus project 1.1 The new EU Atlas The Commission decided earlier this year to issue an ERA-NET Plus call for the creation and publication of a new EU wind atlas. The atlas will cover Member states as well as Member states' exclusive economic zones, both onshore and offshore. It involved the launch of a single joint call for proposals by promoters of national and/or regional programmes, thereby allowing a more efficient use of existing financial resources. Therefore the funding scheme is that of ERA-NET Plus which implies that at least 5 MS shall commit at least 1 million Euros each and the Commission tops up with on third of the MS contribution. Basically it is the MS research programmes that will execute the project but an important part of the project is to create "open project development platforms" with associated protocols allowing a wider range of scientists worldwide to contribute. The project has a duration of 5 years. The decision on the new wind atlas was taken after several years of work by the European Wind Energy Technology Platform and the European Energy Research Alliances' Joint programme for Wind Energy. 2. Structure of the project The project will be structured around three areas of work, to be implemented in parallel: 2.1 Creation and publication of a European wind atlas in electronic form, which will include the underlying data and a new EU wind climate database. The database will at a minimum include: Wind resources and their associated uncertainty; Extreme wind; Turbulence characteristics; Adverse weather conditions; Predictability for short term prediction; Guidelines. 2.2 Development of dynamical downscaling methodologies and open-source models. The developed downscaling methodologies and models will be fully documented and made public available and will be used to produce overview maps of wind resources and relevant data at several heights and a horizontal

  20. European psychiatry: needs, challenges and structures.

    PubMed

    Höschl, Cyril

    2009-11-01

    European psychiatry stays now on the crossroad due to conceptual challenges, drifts of political power from the national to the European level, the current economical situation, arising ethical concerns and an emphasis on patients rights. The latter challenge mainly the structure of mental health care demanding a more important role of patients and families. The needs of harmonisation of research, educational, legislative, and political activities in the field of mental health on the European level are briefly discussed.

  1. European Space Weather Portal Open for Business

    NASA Astrophysics Data System (ADS)

    Staedter, Tracy

    2006-10-01

    This past spring, the European Space Agency (ESA) launched the final release of a centralized Web site designed to showcase a variety of applications, services, and data products revolving around space weather. Called SWENET (Space Weather European Network), the endeavor is expected to create more communication between European scientists and those who use space weather data products and more enthusiasm for space weather among laypeople.

  2. The Revised European Social Fund and Action to Combat Unemployment in the European Community.

    ERIC Educational Resources Information Center

    Vandamme, Francois

    1984-01-01

    The tasks of the European Social Fund, the European Economic Community's social policy instrument, were reviewed in l983 in the light of the worsening unemployment situation and the priority placed on employment and vocational training policies. (Author/SSH)

  3. EMSO: European Multidisciplinary Seafloor Observatory

    NASA Astrophysics Data System (ADS)

    Favali, P.; Partnership, Emso

    2009-04-01

    EMSO, a Research Infrastructure listed within ESFRI (European Strategy Forum on Research Infrastructures) Roadmap), is the European-scale network of multidisciplinary seafloor observatories from the Arctic to the Black Sea with the scientific objective of long-term real-time monitoring of processes related to geosphere/biosphere/hydrosphere interactions. EMSO will enhance our understanding of processes through long time series appropriate to the scale of the phenomena, constituting the new frontier of studying Earth interior, deep-sea biology and chemistry and ocean processes. EMSO will reply also to the need expressed in the frame of GMES (Global Monitoring for Environment and Security) to develop a marine segment integrated in the in situ and satellite global monitoring system. The EMSO development relays upon the synergy between the scientific community and the industry to improve the European competitiveness with respect to countries like USA/Canada, NEPTUNE, VENUS and MARS projects, Taiwan, MACHO project, and Japan, DONET project. In Europe the development of an underwater network is based on previous EU-funded projects since early '90, and presently supported by EU initiatives. The EMSO infrastructure will constitute the extension to the sea of the land-based networks. Examples of data recorded by seafloor observatories will be presented. EMSO is presently at the stage of Preparatory Phase (PP), funded in the EC FP7 Capacities Programme. The project has started in April 2008 and will last 4 years with the participation of 12 Institutions representing 12 countries. EMSO potential will be significantly increased also with the interaction with other Research Infrastructures addressed to Earth Science. 2. IFREMER-Institut Français de Recherche pour l'exploitation de la mer (France, ref. Roland Person); KDM-Konsortium Deutsche Meeresforschung e.V. (Germany, ref. Christoph Waldmann); IMI-Irish Marine Institute (Ireland, ref. Michael Gillooly); UTM-CSIC-Unidad de

  4. Assessing European wild fire vulnerability

    NASA Astrophysics Data System (ADS)

    Oehler, F.; Oliveira, S.; Barredo, J. I.; Camia, A.; Ayanz, J. San Miguel; Pettenella, D.; Mavsar, R.

    2012-04-01

    Wild fire vulnerability is a measure of potential socio-economic damage caused by a fire in a specific area. As such it is an important component of long-term fire risk management, helping policy-makers take informed decisions about adequate expenditures for fire prevention and suppression, and to target those regions at highest risk. This paper presents a first approach to assess wild fire vulnerability at the European level. A conservative approach was chosen that assesses the cost of restoring the previous land cover after a potential fire. Based on the CORINE Land Cover, a restoration cost was established for each land cover class at country level, and an average restoration time was assigned according to the recovery capacity of the land cover. The damage caused by fire was then assessed by discounting the cost of restoring the previous land cover over the restoration period. Three different vulnerability scenarios were considered assuming low, medium and high fire severity causing different levels of damage. Over Europe, the potential damage of wild land fires ranges from 10 - 13, 732 Euro*ha-1*yr-1 for low fire severity, 32 - 45,772 Euro*ha-1*yr-1 for medium fire severity and 54 - 77,812 Euro*ha-1*yr-1 for high fire severity. The least vulnerable are natural grasslands, moors and heathland and sclerophyllous vegetation, while the highest cost occurs for restoring broad-leaved forest. Preliminary validation comparing these estimates with official damage assessments for past fires shows reasonable results. The restoration cost approach allows for a straightforward, data extensive assessment of fire vulnerability at European level. A disadvantage is the inherent simplification of the evaluation procedure with the underestimation of non-markets goods and services. Thus, a second approach has been developed, valuing individual wild land goods and services and assessing their annual flow which is lost for a certain period of time in case of a fire event. However

  5. EMSO: European Multidisciplinary Seafloor Observatory

    NASA Astrophysics Data System (ADS)

    Favali, Paolo

    2010-05-01

    EMSO, a Research Infrastructure listed within ESFRI (European Strategy Forum on Research Infrastructures) Roadmap (Report 2006, http://cordis.europa.eu/esfri/roadmap.htm), is the European-scale network of multidisciplinary seafloor observatories from the Arctic to the Black Sea with the scientific objective of long-term real-time monitoring of processes related to geosphere/biosphere/hydrosphere interactions. EMSO will enhance our understanding of processes through long time series appropriate to the scale of the phenomena, constituting the new frontier of studying Earth interior, deep-sea biology and chemistry and ocean processes. The development of an underwater network is based on previous EU-funded projects since early '90 and is being supported by several EU initiatives, as the on-going ESONET-NoE, coordinated by IFREMER (2007-2011, http://www.esonet-emso.org/esonet-noe/), and aims at gathering together the Research Community of the Ocean Observatories. In 2006 the FP7 Capacities Programme launched a call for Preparatory Phase (PP) projects, that will provide the support to create the legal and organisational entities in charge of managing the infrastructures, and coordinating the financial effort among the countries. Under this call the EMSO-PP project was approved in 2007 with the coordination of INGV and the participation of other 11 Institutions of 11 countries. The project has started in April 2008 and will last 4 years. The EMSO is a key-infrastructure both for Ocean Sciences and for Solid Earth Sciences. In this respect it will enhance and complement profitably the capabilities of other European research infrastructures such as EPOS, ERICON-Aurora Borealis, and SIOS. The perspective of the synergy among EMSO and other ESFRI Research Infrastructures will be outlined. EMSO Partners: IFREMER-Institut Français de Recherche pour l'exploitation de la mer (France, ref. Roland Person); KDM-Konsortium Deutsche Meeresforschung e.V. (Germany, ref. Christoph

  6. Status of European appliance standards

    SciTech Connect

    Turiel, I.; Lebot, B.

    1992-05-01

    The European Community (EC) recently commissioned a study of the impact of potential appliance standards on electricity consumption in the twelve EC nations. This study looks at refrigerators, freezers, dishwashers, clothes washers, and clothes dryers. The impact of minimum efficiency standards on electricity use over the time period from 1995--2010 is estimated. The results of this study were presented to the EC in September of 1991. Revisions were made to the draft report and final copies sent to all interested parties. The member nations of the EC will soon consider whether they wish to implement uniform energy efficiency standards that would take effect in 1995. The results of the study described above will be presented and the political considerations will be discussed. In addition, data describing the appliance market in Europe will be presented.

  7. Carbon sequestration in European croplands.

    PubMed

    Smith, Pete; Falloon, Pete

    2005-01-01

    The Marrakech Accords allow biospheric carbon sinks and sources to be included in attempts to meet emission reduction targets for the first commitment period of the Kyoto Protocol. Forest management, cropland management, grazing land management, and re-vegetation are allowable activities under Article 3.4 of the Kyoto Protocol. Soil carbon sinks (and sources) can, therefore, be included under these activities. Croplands are estimated to be the largest biospheric source of carbon lost to the atmosphere in Europe each year, but the cropland estimate is the most uncertain among all land-use types. It is estimated that European croplands (for Europe as far east as the Urals) lose 300 Tg (C) per year, with the mean figure for the European Union estimated to be 78 Tg (C) per year (with one SD=37). National estimates for EU countries are of a similar order of magnitude on a per-area basis. There is significant potential within Europe to decrease the flux of carbon to the atmosphere from cropland, and for cropland management to sequester soil carbon, relative to the amount of carbon stored in cropland soils at present. The biological potential for carbon storage in European (EU 15) cropland is of the order of 90-120 Tg (C) per year, with a range of options available that include reduced and zero tillage, set-aside, perennial crops, deep rooting crops, more efficient use of organic amendments (animal manure, sewage sludge, cereal straw, compost), improved rotations, irrigation, bioenergy crops, extensification, organic farming, and conversion of arable land to grassland or woodland. The sequestration potential, considering only constraints on land use, amounts of raw materials and available land, is up to 45 Tg (C) per year. The realistic potential and the conservative achievable potentials may be considerably lower than the biological potential because of socioeconomic and other constraints, with a realistically achievable potential estimated to be about 20% of the

  8. Postfledging survival of European starlings

    USGS Publications Warehouse

    Krementz, D.G.; Nichols, J.D.; Hines, J.E.

    1989-01-01

    We tested the hypotheses that mass at fledging and fledge date within the breeding season affect postfledging survival in European Starlings (Sturnus vulgaris). Nestlings were weighed on day 18 after hatch and tagged with individually identifiable patagial tags. Fledge date was recorded. Marked fledglings were resighted during weekly two-day intensive observation periods for 9 weeks postfledging. Post-fledging survival and sighting probabilities were estimated for each of four groups (early or late fledging by heavy or light fledging mass). Body mass was related to post-fledging survival for birds that fledged early. Results were not clear-cut for relative fledge date, although there was weak evidence that this also influenced survival. Highest survival probability estimates occurred in the EARLY-HEAVY group, while the lowest survival estimate occurred in the LATE-LIGHT group. Sighting probabilities differed significantly among groups, emphasizing the need to estimate and compare survival using models which explicitly incorporate sighting probabilities.

  9. The European perspective for LSST

    NASA Astrophysics Data System (ADS)

    Gangler, Emmanuel

    2017-06-01

    LSST is a next generation telescope that will produce an unprecedented data flow. The project goal is to deliver data products such as images and catalogs thus enabling scientific analysis for a wide community of users. As a large scale survey, LSST data will be complementary with other facilities in a wide range of scientific domains, including data from ESA or ESO. European countries have invested in LSST since 2007, in the construction of the camera as well as in the computing effort. This latter will be instrumental in designing the next step: how to distribute LSST data to Europe. Astroinformatics challenges for LSST indeed includes not only the analysis of LSST big data, but also the practical efficiency of the data access.

  10. PRACE - The European HPC Infrastructure

    NASA Astrophysics Data System (ADS)

    Stadelmeyer, Peter

    2014-05-01

    The mission of PRACE (Partnership for Advanced Computing in Europe) is to enable high impact scientific discovery and engineering research and development across all disciplines to enhance European competitiveness for the benefit of society. PRACE seeks to realize this mission by offering world class computing and data management resources and services through a peer review process. This talk gives a general overview about PRACE and the PRACE research infrastructure (RI). PRACE is established as an international not-for-profit association and the PRACE RI is a pan-European supercomputing infrastructure which offers access to computing and data management resources at partner sites distributed throughout Europe. Besides a short summary about the organization, history, and activities of PRACE, it is explained how scientists and researchers from academia and industry from around the world can access PRACE systems and which education and training activities are offered by PRACE. The overview also contains a selection of PRACE contributions to societal challenges and ongoing activities. Examples of the latter are beside others petascaling, application benchmark suite, best practice guides for efficient use of key architectures, application enabling / scaling, new programming models, and industrial applications. The Partnership for Advanced Computing in Europe (PRACE) is an international non-profit association with its seat in Brussels. The PRACE Research Infrastructure provides a persistent world-class high performance computing service for scientists and researchers from academia and industry in Europe. The computer systems and their operations accessible through PRACE are provided by 4 PRACE members (BSC representing Spain, CINECA representing Italy, GCS representing Germany and GENCI representing France). The Implementation Phase of PRACE receives funding from the EU's Seventh Framework Programme (FP7/2007-2013) under grant agreements RI-261557, RI-283493 and RI

  11. Nutritional risk of European elderly.

    PubMed

    de Morais, C; Oliveira, B; Afonso, C; Lumbers, M; Raats, M; de Almeida, M D V

    2013-11-01

    The elderly constitute a population group with a high prevalence of non-communicable chronic diseases and high risk of malnutrition. The aim of this study was to identify factors associated to nutritional risk in free-living European elderly. The sample included 644 European citizens, free living in the community, aged 65 years or more. The sample was quota controlled for age groups (65-74, ≥75 years), gender (male/female) and living circumstances (living alone/with others). Logistic regression was performed to identify factors associated with nutritional risk. Several variables regarding socio-demographic characteristics, food choice, health status and the satisfaction with food-related life were included in the analysis. According to the recoded score of the 'Determine your nutritional health' (NSI checklist), 53% of the elderly were at nutritional risk. Nutritional risk was more likely to occur in elderly who considered that it was more important to choose foods 'easy to chew'; with lower average number of fruit and vegetables (F&V) intake episodes and lower score for general health. It was also found in non-married participants; those that did not identify changes in their appetite; and those that felt changes in health status. In this sample, the lowest nutritional risk was found for body mass index (BMI) around 18.5 kg/m(2). Country of residence, gender and age were not found to have a significant effect on nutritional risk. Attention should be drawn to the living circumstances, changes in appetite or health, the general heath perception, F&V intake, choice of foods easy to chew and having a low or high BMI.

  12. Equal Opportunities and European Educational/Vocational Policy [and] Equal Opportunities and the European Social Fund.

    ERIC Educational Resources Information Center

    Brine, Jacky

    This document contains a symposium paper and a conference paper. "Equal Opportunities and European Educational and Vocational Policy" explores the symposium theme of concepts of difference as it relates directly to the European discourse of equal opportunities and its influence on European educational and vocational policy. It outlines…

  13. EERA and Its European Conferences on Educational Research: A Patchwork of Research on European Educational Research

    ERIC Educational Resources Information Center

    Keiner, Edwin; Hofbauer, Susann

    2014-01-01

    The process of Europeanisation is closely linked to the process of an emerging European Educational Research Area and an education research identity. The European Conferences on Educational Research (ECER), European Educational Research Association (EERA) and its networks are involved in new directions and strands of educational research in…

  14. Cultural Diversity among American and European Businesspersons.

    ERIC Educational Resources Information Center

    West, Judy F.; Nixon, Judy C.

    An astute American, knowledgeable of and sensitive to cultural diversities among Europeans can communicate effectively for business success. The results of research into the communication customs of 27 European countries are presented: the Big Three (France, Germany, United Kingdom--England, Northern Ireland, Scotland, and Wales); Western…

  15. Implications of 1992 for European Telecommunications.

    ERIC Educational Resources Information Center

    Muller, Jurgen

    This paper analyzes the effect of the unified single market of 1992 on European telecommunications. The major policy aspects of the European Economic Commission's Green Paper on "The Development of the Common Market for Telecommunications Services and Equipment" are highlighted, and the effects of these policies in the equipment market…

  16. The Words That Buoy the European Impulse.

    ERIC Educational Resources Information Center

    Hogenraad, Robert; Tousignant, Nathalie; Castano, Emanuele; Bestgen, Yves; Dumoulin, Michel

    With a view on analyzing the deeper trends in the European discourse that will shape the European Union's (EU's) future, a study examined 121 speeches made by EU political leaders over the period 1985-1997 and concorded and statisticized which words were used, how often, where, and when with the help of a computer-aided content analysis engine.…

  17. European Scientific Notes, Volume 24, Number 1,

    DTIC Science & Technology

    The publication presents brief articles concerning recent developments in European scientific research. It is hoped that these articles (which do not constitute part of the scientific literature) may prove of value to both American and European scientists by disclosing interesting information well in advance of the usual scientific publications . (Author)

  18. The Future of Copyright Management: European Perspectives.

    ERIC Educational Resources Information Center

    Battisti, Michele

    This paper presents European perspectives on the future of copyright management. The first section is an overview of intellectual property rights in Europe, including differences between copyright countries and "droit d'auteur" countries. The second section addresses European Community legal policy, including examples related to the…

  19. European and Intercultural Dimension in Greek Education

    ERIC Educational Resources Information Center

    Damanakis, Michael

    2005-01-01

    Negotiations concerning Greece's accession into the European Union began as early as 1961, when a cooperation agreement was signed between Greece and the European Economic Community. These negotiations were concluded 20 years later, on 1 January 1981, when Greece became the tenth full member of the EU. The next major step in Greece's progress…

  20. Universal Services in the European Union.

    ERIC Educational Resources Information Center

    Bauer, Johannes M.

    1999-01-01

    Discusses universal service policies in the European Union. Topics include information access; the demise of the public service model; the effects of competition on universal service; financing; national implementation of member states; programs for schools and libraries; and pertinent Web sites on European universal service policy. (LRW)