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Sample records for boreal scots pine

  1. Scots pine chemotypic characterization in a boreal forest stand

    NASA Astrophysics Data System (ADS)

    Bäck, J. K.; Aalto, J.; Henriksson, M.; Hakola, H.; Rinne, J.

    2009-12-01

    Branch scale VOC emissions and above-canopy VOC concentrations have been characterized in several long-term studies in a mature boreal Scots pine (Pinus sylvestris L.) stand in southern Finland, SMEAR II measuring station. The above-canopy monoterpene concentrations in the site have been dominated by α-pinene, which on an average is three times more abundant than the second most common monoterpene, D3-carene. On the contrary, in the branch scale measurements D3-carene is 4-5 times more abundant than α-pinene. The emitted monoterpene mixture has significant implications on air chemistry at the boundary layer, and thus a more detailed understanding on how the emissions vary within the stand is needed. To clarify the variation in the monoterpene emission mixture within the SMEAR II Scots pine population, we collected branches from 40 trees with a systematic sampling scheme, and brought them into the laboratory where we measured their emission spectrum with a gas chromatograph-mass spectrometer (GC-MS). Branches were collected from southward facing direction of the mid-canopy, and stored in cold before collecting the emissions from the topmost part of the branch into Tenax TA adsorbent. Large differences in emission spectrum were seen between the studied pine trees. α-pinene and D3-carene formed together 63-96% of the branch monoterpene emissions. Only in one tree β-pinene emissions overruled these two major components. A significant proportion (22.5%) of the pine population could be characterized as high carene emitters, i.e. their D3-carene emissions were more than 50% larger than their α-pinene emissions. In minimum the α-pinene emissions were only one tenth of the D3-carene emissions. Terpinolene emission was positively correlated with the high D3-carene emissions. Five trees (12.5%) emitted mostly α- and β-pinenes, and in these branches only remnants of D3-carene (less than 10% of total monoterpene emissions) were measured. Camphene, limonene and

  2. Computations on frost damage to Scots pine under climatic warming in boreal conditions

    SciTech Connect

    Kellomaeki, S.; Haenninen, H.; Kolstroem, M.

    1995-02-01

    To investigate the risk of frost damage to Scots pine (Pinus sylvestris L.) in northern regions under climatic warming, a submodel for such damage to trees was included in a forest ecosystem model of the gap type. An annual growth multiplier describing the effects of frost was calculated with the help of simulated daily frost hardiness and daily minimum temperature. The annual growth multiplier was used in the main ecosystem model when simulating the development of a tree stand using a time step of one year. Simulations of the growth and development of Scots pine stands in southern Finland (61{degrees} N) under an elevating temperature indicated that climatic warming could increase the risk of frost damage due to premature onset of growth during warm spells in the late winter and early spring. Risk of frost damage implies uncertainty in yield expectations from boreal forest ecosystems in the event of climatic warming. 38 refs., 9 figs., 4 tabs.

  3. Chemodiversity in terpene emissions at a boreal Scots pine stand

    NASA Astrophysics Data System (ADS)

    Bäck, J.; Aalto, J.; Henriksson, M.; Hakola, H.; He, Q.; Boy, M.

    2011-10-01

    Atmospheric chemistry in background areas is strongly influenced by natural vegetation. Coniferous forests are known to produce large quantities of volatile vapors, especially terpenes to the surrounding air. These compounds are reactive in the atmosphere, and contribute to the formation and growth of atmospheric new particles. Our aim was to analyze the variability of mono- and sesquiterpene emissions between Scots pine trees, in order to clarify the potential errors caused by using emission data obtained from only a few trees in atmospheric chemistry models. We also aimed at testing if stand history and seed origin has an influence on the chemotypic diversity. The inherited, chemotypic variability in mono- and sesquiterpene emission was studied in a seemingly homogeneous 47-yr-old stand in Southern Finland, where two areas differing in their stand regeneration history could be distinguished. Sampling was conducted in August 2009. Terpene concentrations in the air had been measured at the same site for seven years prior to branch sampling for chemotypes. Two main compounds, α-pinene and Δ3-carene formed together 40-97% of the monoterpene proportions in both the branch emissions and in the air concentrations. The data showed a bimodal distribution in emission composition, in particular in Δ3-carene emission within the studied population. 10% of the trees emitted mainly α-pinene and no Δ3-carene at all, whereas 20% of the trees where characterized as high Δ3-carene emitters (Δ3-carene forming >80% of total emitted monoterpene spectrum). An intermediate group of trees emitted equal amounts of both α-pinene and Δ3-carene. The emission pattern of trees at the area established using seeding as the artificial regeneration method differed from the naturally regenerated or planted trees, being mainly high Δ3-carene emitters. Some differences were also seen in e.g. camphene and limonene emissions between chemotypes, but sesquiterpene emissions did not differ

  4. Above- and belowground fluxes of CH4 from boreal shrubs and Scots pine

    NASA Astrophysics Data System (ADS)

    Halmeenmäki, Elisa; Heinonsalo, Jussi; Santalahti, Minna; Putkinen, Anuliina; Fritze, Hannu; Pihlatie, Mari

    2016-04-01

    Boreal upland forests are considered as an important sink for the greenhouse gas methane (CH4) due to CH4 oxidizing microbes in the soil. However, recent evidence suggests that vegetation can act as a significant source of CH4. Also, preliminary measurements indicate occasional emissions of CH4 above the tree canopies of a boreal forest. Nevertheless, the sources and the mechanisms of the observed CH4 emissions are still mostly unknown. Furthermore, the majority of CH4 flux studies have been conducted with the soil chamber method, thus not considering the role of the vegetation itself. We conducted a laboratory experiment to study separately the above- and belowground CH4 fluxes of bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), heather (Calluna vulgaris), and Scots pine (Pinus sylvestris), which were grown in microcosms. The above- and belowground fluxes of the plants were measured separately, and these fluxes were compared to fluxes of microcosms containing only humus soil. In addition to the flux measurements, we analysed the CH4 producing archaea (methanogens) and the CH4 consuming bacteria (methanotrophs) with the qPCR method to discover whether these microbes contribute to the CH4 exchange from the plant material and the soil. The results of the flux measurements indicate that the humus soil with roots of lingonberry, heather, and Scots pine consume CH4 compared to bare humus soil. Simultaneously, the shoots of heather and Scots pine emit small amounts of CH4. We did not find detectable amounts of methanogens from any of the samples, suggesting the produced CH4 could be of non-microbial origin, or produced by very small population of methanogens. Based on the first preliminary results, methanotrophs were present in all the studied plant species, and especially in high amounts in the rooted soils, thus implying that the methanotrophs could be responsible of the CH4 uptake in the root-soil systems.

  5. Effects of snow condition on microbial respiration of Scots pine needle litter in a boreal forest

    NASA Astrophysics Data System (ADS)

    Ohnuki, Masataka; Domisch, Timo; Dannoura, Masako; Ataka, Mioko; Finér, Leena; Repo, Tapani; Osawa, Akira

    2016-04-01

    Climate warming scenarios predict decreasing snow depths and increasing winter precipitation in boreal forests ("rain on snow"). I These conditions may affect the decomposition and the microbial respiration of leaf litter, contributing a major part of tree litters, To understand how different snow conditions during winter would affect the microbial respiration of Scots pine needle litter in a boreal forest, we conducted a laboratory experiment using needle litter of two age classes (newly dropped and older litter). The experiment simulated four different winter treatments, followed by spring and early summer : (1) ambient snow cover (SNOW), (2) Compressed snow and ice encasement (ICE), (3) frozen flood (FLOOD) and (4) no snow cover at all (NO SNOW). The experiment was carried out in four walk-in dasotrons (n=3) with soil temperatures of -2° C and air temperatures of 2° C during winter and increased to 15° C and 20° C during spring, respectively . Needle litter samples were collected three times (prior to the winter, just after winter and at the end of the experiment). We evaluated the microbial respiration from the litter at several temperatures (-5° C, 0° C, 5° C and 12° C), the SIR index (an index estimating the microbial biomass), and the C/N ratio .And we calculated Q10 value (index of microbial respiration activity) using microbial respiration data. We found significant differences in microbial respiration between the newly dropped and older litter at the beginning and at the end of the experiment. However, there were no significant differences in Q10 value and the SIR (index of microbial biomass) between the different winter treatments. All samples showed decrease of microbial activity with time. Finally, we conclude that the winter snow conditions with mild air temperatures as used in our experiment, are not detrimentally affecting the Scots pine needle litter decomposition and its respiration.

  6. Seasonal and inter-annual variability of energy exchange above a boreal Scots pine forest

    NASA Astrophysics Data System (ADS)

    Launiainen, S.

    2010-12-01

    Twelve-years of eddy-covariance measurements conducted above a boreal Scots pine forest in Hyytiälä, Southern Finland, were analyzed to assess the seasonal and inter-annual variability of surface conductance (gs) and energy partitioning. The gs had distinct annual course, driven by the seasonal cycle of the Scots pine. Low gs (2-3 mm s-1 in April) cause the sensible heat flux to peak in May-June while evapotranspiration takes over later in July-August when gs is typically 5-7 mm s-1. Hence, during normal years Bowen ratio decreases from 4-6 in April to 0.7-0.9 in August. Sensitivity of gs to ambient vapor pressure deficit (D) was relatively constant but the reference value at D = 1 kPa varied seasonally and between years. Only two drought episodes when volumetric soil moisture content in upper mineral soil decreased below 0.15 m3 m-3 occurred during the period. Below this threshold value, transpiration was strongly reduced, which promoted sensible heat exchange increasing Bowen ratio to 3-4. Annual evapotranspiration varied between 218 and 361 mm and accounted between 50% and 90% of equilibrium evaporation. The forest floor contributed between 16 and 25% of the total evapotranspiration on annual scale. The fraction stayed similar over the observed range of environmental conditions including drought periods. The inter-annual variability of evapotranspiration could not be linked to any mean climate variable while the summertime sensible heat flux and net radiation were well explained by global radiation. The energy balance closure varied annually between 0.66 and 0.95 and had a distinct seasonal cycle with worse closure in spring when a large proportion of available energy is partitioned into sensible heat.

  7. Seasonal and inter annual variability of energy exchange above a boreal Scots pine forest

    NASA Astrophysics Data System (ADS)

    Launiainen, S.

    2010-08-01

    Twelve-years of eddy-covariance measurements conducted above a boreal Scots pine forest in Hyytiälä, Southern Finland, were analyzed to assess the seasonal and inter-annual variability of surface conductance (gs) and energy partitioning. The gs had distinct annual course, driven by the seasonal cycle of the Scots pine. Low gs (2-3 mm s-1 in April) restricted transpiration in springtime and caused the sensible heat flux to peak in May-June while evapotranspiration takes over later in July-August when gs is typically 5-7 mm s-1. Hence, during normal years Bowen ratio decreases from 4-6 in April to 0.7-0.9 in August. Sensitivity of gs to ambient vapor pressure deficit (D) was relatively constant but the reference value at D=1 kPa varied seasonally and between years. Only two drought episodes when volumetric soil moisture content in upper mineral soil decreased below 0.15 m3 m-3 occurred during the period. Below this threshold value transpiration was strongly reduced, which promoted sensible heat exchange increasing Bowen ratio to 3-4. Annual evapotranspiration varied between 218 and 361 mm and accounted between 50% and 90% of equilibrium evaporation. The forest floor contributed between 16 and 25% of the total evapotranspiration on annual scale. The fraction stayed similar over the observed range of environmental conditions including drought. The inter-annual variability of evapotranspiration could not be linked to any mean climate parameter while the summertime sensible heat flux and net radiation were well explained by global radiation. The energy balance closure varied annually between 0.66 and 0.95 and had a distinct seasonal cycle with worse closure in spring when large proportion of available energy is partitioned into sensible heat.

  8. Long-term nitrogen additions and the intrinsic water-use efficiency of boreal Scots pine.

    NASA Astrophysics Data System (ADS)

    Marshall, John; Wallin, Göran; Linder, Sune; Lundmark, Tomas; Näsholm, Torgny

    2015-04-01

    Nitrogen fertilization nearly always increases productivity in boreal forests, at least in terms of wood production, but it is unclear how. In a mature (80 yrs. old) Scots pine forest in northern Sweden, we tested the extent to which nitrogen fertilization increased intrinsic photosynthetic water-use efficiency. We measured δ13C both discretely, in biweekly phloem sampling, and continuously, by monitoring of bole respiration. The original experiment was designed as a test of eddy covariance methods and is not therefore strictly replicated. Nonetheless, we compared phloem contents among fifteen trees from each plot and stem respiration from four per plot. The treatments included addition of 100 kg N/ha for eight years and a control. Phloem contents have the advantage of integrating over the whole canopy and undergoing complete and rapid turnover. Their disadvantage is that some have observed isotopic drift with transport down the length of the stem, presumably as a result of preferential export and/or reloading. We also measured the isotopic composition of stem respiration from four trees on each plot using a Picarro G1101-I CRDS attached to the vent flow from a continuous gas-exchange system. We detected consistent differences in δ13C between the treatments in phloem contents. Within each treatment, the phloem δ13C was negatively correlated with antecedent temperature (R2= 0.65) and no other measured climate variable. The isotopic composition of stem CO2 efflux will be compared to that of phloem contents. However, when converted to intrinsic water-use efficiency, the increase amounted to only about 4%. This is a small relative to the near doubling in wood production. Although we were able to detect a clear and consistent increase in water-use efficiency with N-fertilization, it constitutes but a minor cause of the observed increase in wood production.

  9. Autumn temperature and carbon balance of a boreal Scots pine forest in Southern Finland

    NASA Astrophysics Data System (ADS)

    Vesala, T.; Launiainen, S.; Kolari, P.; Pumpanen, J.; Sevanto, S.; Hari, P.; Nikinmaa, E.; Kaski, P.; Mannila, H.; Ukkonen, E.; Piao, S. L.; Ciais, P.

    2010-01-01

    We analyzed the dynamics of carbon balance components: gross primary production (GPP) and total ecosystem respiration (TER), of a boreal Scots pine forest in Southern Finland. The main focus is on investigations of environmental drivers of GPP and TER and how they affect the inter-annual variation in the carbon balance in autumn (September-December). We used standard climate data and CO2 exchange measurements collected by the eddy covariance (EC) technique over 11 years. EC data revealed that increasing autumn temperature significantly enhances TER: the temperature sensitivity was 9.5 gC m-2 °C-1 for the period September-October (early autumn when high radiation levels still occur) and 3.8 gC m-2 °C-1 for November-December (late autumn with suppressed radiation level). The cumulative GPP was practically independent of the temperature in early autumn. In late autumn, air temperature could explain part of the variation in GPP but the temperature sensitivity was very weak, less than 1 gC m-2 °C-1. Two models, a stand photosynthesis model (COCA) and a global vegetation model (ORCHIDEE), were used for estimating stand GPP and its sensitivity to the temperature. The ORCHIDEE model was tested against the observations of GPP derived from EC data. The stand photosynthesis model COCA predicted that under a predescribed 3-6 °C temperature increase, the temperature sensitivity of 4-5 gC m-2 °C-1 in GPP may appear in early autumn. The analysis by the ORCHIDEE model revealed the model sensitivity to the temporal treatment of meteorological forcing. The model predictions were similar to observed ones when the site level 1/2-hourly time step was applied, but the results calculated by using daily meteorological forcing, interpolated to 1/2-hourly time step, were biased. This is due to the nonlinear relationship between the processes and the environmental factors.

  10. Modelling and measurement of solar induced fluorescence in a boreal scots pine canopy

    NASA Astrophysics Data System (ADS)

    Nichol, C. J.; Drolet, G.; Atherton, J.; Wade, T. J.; Porcar-Castell, A.; Levula, J.; Nikinmaa, E.; Vesala, T.

    2012-12-01

    temperature and photo-inhibition must be taken into account. We further present the strengths and weaknesses of retrieving Fs from field based radiance measurements in a strongly seasonal Scots pine canopy in boreal Finland, and explore the utility of Fs to track the seasonality in ecosystem photosynthetic light use efficiency and gross primary productivity.

  11. Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest

    NASA Astrophysics Data System (ADS)

    Taipale, R.; Kajos, M. K.; Patokoski, J.; Rantala, P.; Ruuskanen, T. M.; Rinne, J.

    2011-08-01

    Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis at the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a correlation analysis and a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May-August 2007, the monthly medians of daytime emissions were 200, 290, 180, and 200 μg m-2 h-1. The emissions were partly light dependent, probably due to de novo biosynthesis. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30 % and 46 %. Although the monthly changes were not significant, the ratio always differed statistically from zero, suggesting that the role of de novo biosynthesis was observable. Given the uncertainties in this study, we conclude that more accurate estimates of the contribution of de novo emissions are required for improving monoterpene emission algorithms for Scots pine dominated forests.

  12. Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest

    NASA Astrophysics Data System (ADS)

    Taipale, R.; Kajos, M. K.; Patokoski, J.; Rantala, P.; Ruuskanen, T. M.; Rinne, J.

    2010-11-01

    Monoterpene emissions from Scots pine have traditionally been assumed to originate as evaporation from specialized storage pools. More recently, the significance of de novo emissions, originating directly from monoterpene biosynthesis, has been recognized. To study the role of biosynthesis in the ecosystem scale, we measured monoterpene emissions from a Scots pine dominated forest in southern Finland using the disjunct eddy covariance method combined with proton transfer reaction mass spectrometry. The interpretation of the measurements was based on a hybrid emission algorithm describing both de novo and pool emissions. During the measurement period May-August 2007, the monthly medians of daytime emissions were 170, 280, 180, and 180 μg m-2 h-1. The emission potential for both de novo and pool emissions exhibited a decreasing summertime trend. The ratio of the de novo emission potential to the total emission potential varied between 30% and 46%. Although the monthly changes were not significant, the ratio always differed statistically from zero, i.e., the role of de novo biosynthesis was evident. The hybrid approach showed promising potential for the improvement of the ecosystem scale emission modelling. Given this feature and the significant role of biosynthesis, we recommend incorporating both de novo and pool emissions into the monoterpene emission algorithms for Scots pine dominated forests.

  13. Diurnal patterns in Scots pine stem oleoresin pressure in a boreal forest.

    PubMed

    Rissanen, K; Hölttä, T; Vanhatalo, A; Aalto, J; Nikinmaa, E; Rita, H; Bäck, J

    2016-03-01

    Coniferous tree stems contain large amounts of oleoresin under positive pressure in the resin ducts. Studies in North-American pines indicated that the stem oleoresin exudation pressure (OEP) correlates negatively with transpiration rate and soil water content. However, it is not known how the OEP changes affect the emissions of volatile vapours from the trees. We measured the OEP, xylem diameter changes indicating changes in xylem water potential and monoterpene emissions under field conditions in mature Scots pine (Pinus sylvestris L.) trees in southern Finland. Contrary to earlier reports, the diurnal OEP changes were positively correlated with temperature and transpiration rate. OEP was lowest at the top part of the stem, where water potentials were also more negative, and often closely linked to ambient temperature and stem monoterpene emissions. However, occasionally OEP was affected by sudden changes in vapour pressure deficit (VPD), indicating the importance of xylem water potential on OEP as well. We conclude that the oleoresin storage pools in tree stems are in a dynamic relationship with ambient temperature and xylem water potential, and that the canopy monoterpene emission rates may therefore be also regulated by whole tree processes and not only by the conditions prevailing in the upper canopy. PMID:26385487

  14. Nitrogen Fertilization Modifies the Phenology of Ground CO2 Efflux in a Boreal Scots Pine Forest

    NASA Astrophysics Data System (ADS)

    Marshall, J. D.; Näsholm, T.; Linder, S.; Tarvainen, L.; Peichl, M.; Lundmark, T.

    2015-12-01

    Problems with the extraction of ecosystem respiration rates from eddy covariance data have led to renewed interest in chamber-based estimates of CO2 efflux from near the ground surface. However, chamber measurements frequently have their own issues. Here we describe the results of a study using large (≈2 m radius), transparent chambers over intact ground vegetation to describe the net efflux of CO2 and its environmental controls during the growing season at Rosinedal, a research site in northern Sweden. Measurements were made at thirty-minute intervals over the course of three growing seasons in a heavily fertilized and an unfertilized Scots pine stand. Ammonium nitrate was added at rates of 100 kg N ha-1 for the first five years, after which the rate was halved but the additions continued. The CO2 efflux results were simultaneously fitted to a nonlinear model describing the exponential increase in dark efflux with temperature, the Michaelis-Menten saturation of light-driven CO2 uptake in photosynthesis, the reduction in efflux due to soil drying, and a residual term that we ascribe to weekly shifts in the photosynthate partitioning of canopy trees to belowground processes. We found the expected exponential increase in dark efflux with temperature, however the net efflux in daytime was often negative, reflecting the high GPP of the ground vegetation, especially in dense canopies of bilberry (Vaccinium myrtillus L.). There was a clear reduction in dark efflux under dry conditions. The empirical phenology parameters increased sharply in early July, around the time that leaf expansion and rapid cambial growth were completed. This increase was more pronounced on the control plot than on the fertilized plot, consistent with expectations based on the notion that N fertilization should favor aboveground partitioning. The empirical "partitioning coefficient" shifted net efflux by nearly as much as the seasonal temperature range. Dark efflux of CO2 was nearly halved as a

  15. Field and controlled environment measurements show strong seasonal acclimation in photosynthesis and respiration potential in boreal Scots pine.

    PubMed

    Kolari, Pasi; Chan, Tommy; Porcar-Castell, Albert; Bäck, Jaana; Nikinmaa, Eero; Juurola, Eija

    2014-01-01

    Understanding the seasonality of photosynthesis in boreal evergreen trees and its control by the environment requires separation of the instantaneous and slow responses, as well as the dynamics of light reactions, carbon reactions, and respiration. We determined the seasonality of photosynthetic light response and respiration parameters of Scots pine (Pinus sylvestris L.) in the field in southern Finland and in controlled laboratory conditions. CO2 exchange and chlorophyll fluorescence were measured in the field using a continuously operated automated chamber setup and fluorescence monitoring systems. We also carried out monthly measurements of photosynthetic light, CO2 and temperature responses in standard conditions with a portable IRGA and fluorometer instrument. The field and response measurements indicated strong seasonal variability in the state of the photosynthetic machinery with a deep downregulation during winter. Despite the downregulation, the photosynthetic machinery retained a significant capacity during winter, which was not visible in the field measurements. Light-saturated photosynthesis (P sat) and the initial slope of the photosynthetic light response (α) obtained in standard conditions were up to 20% of their respective summertime values. Respiration also showed seasonal acclimation with peak values of respiration in standard temperature in spring and decline in autumn. Spring recovery of all photosynthetic parameters could be predicted with temperature history. On the other hand, the operating quantum yield of photosystem II and the initial slope of photosynthetic light response stayed almost at the summertime level until late autumn while at the same time P sat decreased following the prevailing temperature. Comparison of photosynthetic parameters with the environmental drivers suggests that light and minimum temperature are also decisive factors in the seasonal acclimation of photosynthesis in boreal evergreen trees. PMID:25566291

  16. Field and controlled environment measurements show strong seasonal acclimation in photosynthesis and respiration potential in boreal Scots pine

    PubMed Central

    Kolari, Pasi; Chan, Tommy; Porcar-Castell, Albert; Bäck, Jaana; Nikinmaa, Eero; Juurola, Eija

    2014-01-01

    Understanding the seasonality of photosynthesis in boreal evergreen trees and its control by the environment requires separation of the instantaneous and slow responses, as well as the dynamics of light reactions, carbon reactions, and respiration. We determined the seasonality of photosynthetic light response and respiration parameters of Scots pine (Pinus sylvestris L.) in the field in southern Finland and in controlled laboratory conditions. CO2 exchange and chlorophyll fluorescence were measured in the field using a continuously operated automated chamber setup and fluorescence monitoring systems. We also carried out monthly measurements of photosynthetic light, CO2 and temperature responses in standard conditions with a portable IRGA and fluorometer instrument. The field and response measurements indicated strong seasonal variability in the state of the photosynthetic machinery with a deep downregulation during winter. Despite the downregulation, the photosynthetic machinery retained a significant capacity during winter, which was not visible in the field measurements. Light-saturated photosynthesis (Psat) and the initial slope of the photosynthetic light response (α) obtained in standard conditions were up to 20% of their respective summertime values. Respiration also showed seasonal acclimation with peak values of respiration in standard temperature in spring and decline in autumn. Spring recovery of all photosynthetic parameters could be predicted with temperature history. On the other hand, the operating quantum yield of photosystem II and the initial slope of photosynthetic light response stayed almost at the summertime level until late autumn while at the same time Psat decreased following the prevailing temperature. Comparison of photosynthetic parameters with the environmental drivers suggests that light and minimum temperature are also decisive factors in the seasonal acclimation of photosynthesis in boreal evergreen trees. PMID:25566291

  17. Gas-phase alkylamines in a boreal Scots pine forest air

    NASA Astrophysics Data System (ADS)

    Kieloaho, Antti-Jussi; Hellén, Heidi; Hakola, Hannele; Manninen, Hanna E.; Nieminen, Tuomo; Kulmala, Markku; Pihlatie, Mari

    2013-12-01

    Alkylamines are highly reactive volatile nitrogen compounds that may take part in aerosol formation and growth in the atmosphere in boreal forests. We measured alkylamine concentrations from May to October 2011 in a boreal forest at the SMEAR II station in Hyytiälä, southern Finland. The weekly air samples were collected in phosphoric acid-impregnated fiberglass filters through a polytetrafluoroethylene (PTFE) filter and analyzed with a high performance liquid chromatography electrospray ionization ion-trap mass spectrometer. Ethylamine (EA) and dimethylamine (DMA), propylamine (PA) and trimethylamine (TMA), and diethylamine (DEA) were observed on levels above the detection limits, while butylamine and triethylamine were under the detection limits. The highest concentrations for EA + DMA (157 ± 20 pptV) and PA + TMA (102 ± 61 pptV) were observed from September to October. For DEA the seasonal course was different and the highest concentrations were measured during the summer (max 15.5 ± 0.5 pptV, early July). The amine concentrations were compared with those of ambient air ions, other trace gases (O3, NO, NOx and CO and monoterpenes), and with soil and air temperatures and litterfall. Positive and negative cluster ions did not correlate with the amine concentration measured. However, peaks in the positive and negative intermediate ions showing similar concentrations occurred simultaneously with peaks in EA + DMA and DEA during the summer. The number of new particle formation days followed the sum of the alkylamine concentrations observed during the autumn. The autumnal monoterpene emissions from the forest floor and litterfall maxima coincided with the elevated or peaked EA + DMA and PA + TMA concentrations. Similar to the monoterpene concentrations in the forest air, amine concentrations seem to be linked with vegetation, soil activity, and litterfall, and rather than with other trace gases in the atmosphere.

  18. Seasonal variations in gas-phase alkyl amines in the ambient air of a boreal Scots pine forest

    NASA Astrophysics Data System (ADS)

    Kieloaho, Antti-Jussi; Hellén, Heidi; Hakola, Hannele; Manninen, Hanna; Pihlatie, Mari

    2013-04-01

    Alkyl amines are highly reactive volatile nitrogen compounds that have been suggested to take part in aerosol formation and growth in the atmosphere. Despite this, the sources of these compounds are unknown and there are no long-term measurements available. We measured alkyl amine concentrations from May to October in 2011 in the trunk space of a boreal forest at the SMEAR II station in Hyytiälä, Southern Finland (61°51'N, 24°17'E, 180 m a.s.l.). The weekly air samples were collected into phosphoric acid impregnated glass fibre filters through PTFE filter and analysed by high performance liquid chromatography electrospray ionisation ion trap mass spectrometer (Agilent 1100 series LC/MSD trap). Ethylamine and dimethylamine (EA+DMA), propylamine and trimetylamine (PA+TMA) and diethylamine (DEA) were observed on levels above the detection limits. The highest concentrations were observed from September to October for EA+DMA (157±20 ppt) and for PA+TMA (102±61 ppt). Mixing ratios of EA+DMA also peaked on weeks 24th, 30th and 35th and TMA+PA on week 36th; however, these peaks were approximately half of those observed in the autumn. DEA annual curve was different than that of the other amines. Instead of the autumn peaks, the highest mixing ratios were measured during the summer (max 15.5±0.5 ppt , early July). In the autumn the DEA mixing ratios were slightly higher than in early spring, however about half of that measured in the summer. Amine concentrations were compared to cluster ion and monoterpene concentrations, monoterpene emissions, and to soil and air temperatures and litterfall. Positive and negative cluster ions did not correlate with the measured amine concentrations. However, during the summer, peaks in positive cluster ions occurred simultaneously with peaks in EA+DMA and DEA. During the autumn, negative cluster ions peaked with EA+DMA. Autumnal monoterpene emissions from the forest floor coincide with the elevated or peaked EA+DMA and PA

  19. Diel cycles of isoprenoids in the emissions of Norway spruce, four Scots pine chemotypes, and in Boreal forest ambient air during HUMPPA-COPEC-2010

    NASA Astrophysics Data System (ADS)

    Yassaa, N.; Song, W.; Lelieveld, J.; Vanhatalo, A.; Bäck, J.; Williams, J.

    2012-04-01

    Branch enclosure based emission rates of monoterpenes and sesquiterpenes from four Scots pines (Pinus sylvestris) and one Norway spruce (Picea abies), as well as the ambient mixing ratios of monoterpenes were determined during the HUMPPA-COPEC 2010 summer campaign. Differences in chemical composition and in emission strength were observed between the different trees, which confirmed that they represented different chemotypes. The chemotypes of Scots pine can be classified according to species with high, no and intermediate content of Δ-3-carene. The "non-Δ-3-carene" chemotype was found to be the strongest emitter of monoterpenes. From this chemotype, β-myrcene, a very reactive monoterpene, was the dominant species accounting for more than 32% of the total emission rates of isoprenoids followed by β-phellandrene (~27%). Myrcene fluxes ranged from 0.8 to 24 μg g-1 (dw) h-1. α-Farnesene was the dominant sesquiterpene species, with average emission rates of 318 ng g-1 (dw) h-1. In the high Δ-3-carene chemotype, more than 48% of the total monoterpene emission was Δ-3-carene. The average Δ-3-carene emission rate, circa 609 ng g-1 (dw) h-1 reported here is consistent with the previously reported summer season value. The monoterpene emissions from spruce were dominated by limonene (35%), β-phellandrene (15%), α-pinene (14%) and eucalyptol (9%). Total spruce monoterpene emissions ranged from 0.55 up to 12.2 μg g-1 (dw) h-1. Overall the total terpene flux (monoterpenes + sesquiterpenes) from all studied tree species varied from 230 ng g-1 (dw) h-1 up to 66 μg g-1 (dw) h-1. Total ambient monoterpenes (including α-pinene, Δ-3-carene, β-pinene and β-myrcene) measured during the campaign varied in mixing ratio from a few pptv to over one ppbv. The most abundant biogenic VOCs measured above the canopy were α-pinene and Δ-3-carene, and these two compounds together contributed more than 50% of the total monoterpenes. The ambient data reflect the emission rate

  20. Diel cycles of isoprenoids in the emissions of Norway spruce, four Scots pine chemotypes, and in Boreal forest ambient air during HUMPPA-COPEC-2010

    NASA Astrophysics Data System (ADS)

    Yassaa, N.; Song, W.; Lelieveld, J.; Vanhatalo, A.; Bäck, J.; Williams, J.

    2012-08-01

    Branch enclosure based emission rates of monoterpenes and sesquiterpenes from four Scots pines (Pinus sylvestris) and one Norway spruce (Picea abies), as well as the ambient mixing ratios of monoterpenes were determined during the HUMPPA-COPEC 2010 summer campaign. Differences in chemical composition and in emission strength were observed between the different trees, which confirmed that they represented different chemotypes. The chemotypes of Scots pine can be classified according to species with high, no and intermediate content of Δ-3-carene. The "non-Δ-3-carene" chemotype was found to be the strongest emitter of monoterpenes. From this chemotype, β-myrcene, a very reactive monoterpene, was the dominant species accounting for more than 32 % of the total emission rates of isoprenoids followed by β-phellandrene (~27%). Myrcene fluxes ranged from 0.8 to 24 μg g-1 (dw) h-1. α-Farnesene was the dominant sesquiterpene species, with average emission rates of 318 ng g-1 (dw) h-1. In the high Δ-3-carene chemotype, more than 48% of the total monoterpene emission was Δ-3-carene. The average Δ-3-carene emission rate (from chemotype 3), circa 609 ng g-1 (dw) h-1 reported here is consistent with the previously reported summer season value. Daily maximum temperatures varied between 20 and 35 °C during the measurements. The monoterpene emissions from spruce were dominated by limonene (35%), β-phellandrene (15%), α-pinene (14%) and eucalyptol (9%). Total spruce monoterpene emissions ranged from 0.55 up to 12.2 μg g-1 (dw) h-1. Overall the total terpene flux (monoterpenes + sesquiterpenes) from all studied tree species varied from 230 ng g-1 (dw) h-1 up to 66 μg g-1 (dw) h-1. Total ambient monoterpenes (including α-pinene, Δ-3-carene, β-pinene and β-myrcene) measured during the campaign varied in mixing ratio from a few pptv to over one ppbv. The most abundant biogenic VOC measured above the canopy were α-pinene and Δ-3-carene, and these two compounds together

  1. Diel cycles of isoprenoids in the emissions of Norway spruce, different Scots pine chemotypes, and in Boreal forest ambient air during HUMPPA-COPEC-2010

    NASA Astrophysics Data System (ADS)

    Yassaa, N.; Williams, J.; Song, W.; Vanhatalo, A.; Bäck, J.; Lelieveld, J.

    2012-04-01

    Cuvette based emission rates of monoterpenes and sesquiterpenes from four chemotypes of Scots pine (Pinus sylvestris) and one chemotype of Norway spruce (Picea abies) as well as the ambient mixing ratios of monoterpenes were determined during HUMPPA-COPEC 2010 summer campaign. Differences in chemical composition as well as in emission strength were observed between the different chemotypes. The chemotypes of Scots pine can be classified according to species with high, no and intermediate content of Δ3-carene. The "no- Δ3-carene" chemotype was found to be the strongest emitter of monoterpenes. From this chemotype, β-myrcene, a very reactive organic gas, was the dominant species accounting for more than 35 % of the total emission rates of isoprenoids followed by ß-phellandrene (~34%). Myrcene emission rates ranged from 0.8 up to 24 µg/g (dw)/h. α-farnesene was the dominant sesquiterpene species, with measured average emission rates of 318 ng/g (dw)/h. In the high Δ3-carene chemotype, which is the most studied in Hyytiälä, Δ3-carene was more than 48 % of the total monoterpene emission. The mean Δ3-carene emission rate, circa 609 ng/g (dw)/h reported here is consistent with the previously reported value during the same season. The terpene emission from spruce was dominated by limonene (35%), ß-phellandrene (15%), α-pinene (14 %) and eucalyptol (9%). Total spruce monoterpene emissions ranged from 0.549 up to 12.2 µg/g (dw)/h. Overall the total terpene flux (monoterpenes + sesquiterpenes) from all studied plant species varied from 230 ng/g (dw)/h up to 66 µg/g (dw)/h. The total ambient monoterpenes (including α-pinene, Δ3-carene, ß-pinene and ß-myrcene) measured during the campaign varied in mixing ratio from a few ppt to over one ppb. The most abundant biogenic VOCs measured above the canopy were α-pinene and Δ3-carene and these two compounds together contributed more than 50% of the total monoterpenes. The diel cycles of isoprenoid mixing ratios

  2. Monoterpene emissions from Scots pine and Norwegian spruce

    NASA Astrophysics Data System (ADS)

    Janson, Robert W.

    1993-02-01

    Rates of monoterpene emissions from Scots pine (Pinus sylvestris) and Norwegian spruce (Picea abies) have been measured at four sites in Sweden with a dynamic flow chamber technique. Forest floor emissions have been made in the pine forest with the static chamber technique. Sampling was done with Tenax TA and analysis and detection by GC and ion trap detection. The compounds Δ3-carene and α-pinene were the predominant terpenes emitted from the crown and floor of the Scots pine forest. Alpha-pinene was the main terpene emitted from Norwegian spruce at the sites in southern and central Sweden, while Δ3-carene was predominant at the northern site. The relative composition of the emission of both species underwent changes in early spring and fall. Emission rates, normalized to temperature, were seen to vary diurnally with a maximum at midday, and seasonally with maxima in early May and October, and a summer maximum in June-July. The possible dependence of the emission rate on needle growth rate and other plant-physiological processes is discussed. A higher emission rate and different relative composition of the emission was seen to occur when the vegetation was wet, as compared to dry vegetation. The emission from the pine forest floor was seen to have a composition different from that of the crown and a seasonality of the rate similar to that of the crown. The ground emission could not be explained by sources in the litter or ground vegetation alone, and it is suggested that the root system of the trees is also an emission source. The emission rate from the pine forest floor was of the order of 30% of the crown emission. The July rate of emission from the crown of Scots pine, normalized to 20°C and averaged over four sites in Sweden, was 0.8 ± 0.4 μg (gdw (grams dry weight) h)-1, and for Norwegian spruce, 0.5 ± 0.7 μg(gdw h)-1. It would seem that previous regional and global estimates of hydrocarbon fluxes to the atmosphere have used emission factors which are

  3. Monoterpene emissions from Scots pine and Norwegian spruce

    SciTech Connect

    Janson, R.W. )

    1993-02-20

    Rates of monoterpene emissions from Scots pine (Pinus sylvestris) and Norwegian spruce (Picea abies) have been measured at four sites in Sweden with a dynamic flow chamber technique. Forest floor emissions have been made in the pine forest with the static chamber technique. The compounds [Delta][sup 3]-carene and [alpha]-pinene were the predominant terpenes emitted from the crown and floor of the Scots pine forest. Alpha-pinene was the main terpene emitted from Norwegian spruce at the sites in southern and central Sweden, while [Delta][sup 3]-carene was predominant at the northern site. Emission rates, normalized to temperature, were seen to vary diurnally with a maximum at midday, and seasonally with maxima in early May and October, and a summer maximum in June-July. The possible dependence of the emission rate on needle growth rate and other plant-physiological processes is discussed. A higher emission rate and different relative composition of the emission was seen to occur when the vegetation was wet, as compared to dry vegetation. The emission from the pine forest floor was seen to have a composition different from that of the crown and a seasonality of the rate similar to that of the crown. The ground emission could not be explained by sources in the litter or ground vegetation alone, and it is suggested that the root system of the trees is also an emission source. The emission rate from the pine forest floor was of the order of 30% of the crown emission. The July rate of emission from the crown of Scots pine, normalized to 20[degrees]C and averaged over four sites in Sweden, was 0.8 [plus minus] 0.4 [mu]g (gdw (grams dry weight) h)[sup [minus]1], and for Norwegian spruce, 0.5 [plus minus] 0.7 [mu]g(gdw h)[sup [minus]1]. It would seem that previous regional and global estimates of hydrocarbon fluxes to the atmosphere have used emission factors which are too high for boreal coniferous forests. 52 refs., 8 figs., 9 tabs.

  4. Responses of Scots pine to waterlogging during growing season

    NASA Astrophysics Data System (ADS)

    Repo, Tapani; Launiainen, Samuli; Lehto, Tarja; Sutinen, Sirkka; Ruhanen, Hanna; Heiskanen, Juha; Laurén, Ari; Silvennoinen, Raimo; Vapaavuori, Elina; Finér, Leena

    2016-04-01

    For the future management and sustainable use of boreal forests it is crucial to consider the rate and strength of tree responses to an elevated water table and the concurrent oxygen limitations, especially in peatlands. We examined the response dynamics of 7-year-old Scots pine (Pinus sylvestris L.) seedlings to a five-week waterlogging (WL) during a growing season in a root lab experiment. WL took place after shoot elongation had ended whereas growth of the trunk diameter was still in progress. We monitored shoots and roots before, during and after WL treatment. Relations between the shoot and root responses, the latter being the primary target of the WL stress, will be discussed. We hypothesize that root responses, in terms of growth by minirhizotron imaging, will appear with delay as compared with the first symptoms in physiology of above-ground organs.

  5. Flux agreement above a Scots pine plantation

    NASA Astrophysics Data System (ADS)

    Gay, L. W.; Vogt, R.; Bernhofer, Ch.; Blanford, J. H.

    1996-03-01

    The surface energy exchange of 12m high Scots pine plantation at Hartheim, Germany, was measured with a variety of methods during a 11-day period of fine weather in mid-May 1992. Net radiation and rate of thermal storage were measured with conventional net radiometers, soil heat flux discs and temperature-based storage models. The turbulent fluxes discussed in this report were obtained with an interchanging Bowen ratio energy budget system (BREB, at 14 m), two one-propeller eddy correlation systems (OPEC systems 1 and 2 at 17m), a 1-dimensional sonic eddy correlation system (SEC system 3) at 15 m, all on one “low” tower, and a 3-dimensional sonic eddy correlation system (SEC system 22) at 22 m on the “high” tower that was about 46 m distant. All systems measured sensible and latent heat (H and LE) directly, except for OPEC systems 1 and 2 which estimated LE as a residual term in the surface energy balance. Closure of turbulent fluxes from the two SEC systems was around 80% for daytime and 30% for night, with closure of 1-dimensional SEC system 3 exceeding that of 3-dimensional SEC system 22. The night measurements of turbulent fluxes contained considerable uncertainty, especially with the BREB system where measured gradients often yielded erroneous fluxes due to problems inherent in the method (i.e., computational instability as Bowen's ratio approaches -1). Also, both eddy correlation system designs (OPEC and SEC) appeared to underestimate |H| during stable conditions at night. In addition, both sonic systems (1- and 3-dimensional) underestimated |LE| during stable conditions. The underestimate of |H| at night generated residual estimates of OPEC LE containing a “phantom dew” error that erroneously decreased daily LE totals by about 10 percent. These special night problems are circumvented here by comparing results for daytime periods only, rather than for full days. To summarize, turbulent fluxes on the low tower from OPEC system 2 and the adjacent

  6. Modeling of bud break of Scots pine in northern Finland in 1908-2014.

    PubMed

    Salminen, Hannu; Jalkanen, Risto

    2015-01-01

    Bud break and height-growth of Scots pine (Pinus sylvestris L.) in the northern boreal zone in Lapland, Finland, was followed through the entire growing seasons in the periods 2001-2003 and 2008-2010 in sapling stands in two different locations in northern Finland set some 250 km apart along a latitudinal transect. Field measurements continued at the southern site also in 2011-2013. Air temperature was recorded hourly at the sites. A simple optimization algorithm (GA) was used to adjust parameters of the models predicting the timing of bud break of Scots pine in order to minimize the difference between observed and predicted dates. The models giving the best performance and century-long daily temperatures were used to reconstruct bud-break time series. The temperature observations were recorded for the period 1908-2014 in Sodankylä, which is located in-between the sapling stands in the north-south direction and for the period 1877-2014 in Karasjok, which is in Norway about 145 km north-west from the northernmost stand of this study. On average buds began to extend in the beginning of May in the southernmost stand and in mid-May in the northernmost stands, and the variation between years was in the range of 3 weeks. A simple day-length-triggered (fixed date) model predicted most accurately the date of bud break; root mean square error (RMSE) was 2 and 4 days in the northern and southern site, respectively. The reconstructed bud-break series indicated that based on temperature observations from Sodankylä, growth onset of Scots pine has clearly advanced since the 1960s, though it currently matches that of the early 1920s and early 1950s. The temperature record from Karasjok indicated a similar variation, though there was a weak linear trend advancing bud break by about 3-4 days over a 100-year period. PMID:25798141

  7. Do multiple herbivores maintain chemical diversity of Scots pine monoterpenes?

    PubMed Central

    Iason, Glenn R.; O'Reilly-Wapstra, Julianne M.; Brewer, Mark J.; Summers, Ron W.; Moore, Ben D.

    2011-01-01

    A central issue in our understanding of the evolution of the diversity of plant secondary metabolites (PSMs) is whether or not compounds are functional, conferring an advantage to the plant, or non-functional. We examine the hypothesis that the diversity of monoterpene PSMs within a plant species (Scots pine Pinus sylvestris) may be explained by different compounds acting as defences against high-impact herbivores operating at different life stages. We also hypothesize that pairwise coevolution, with uncorrelated interactions, is more likely to result in greater PSM diversity, than diffuse coevolution. We tested whether up to 13 different monoterpenes in Scots pine were inhibitory to herbivory by slugs (Arion ater), bank voles (Clethrionomys glareolus), red deer (Cervus elaphus) and capercaillie (Tetrao urogallus), each of which attack trees at a different life stage. Plants containing more α-pinene were avoided by both slugs and capercaillie, which may act as reinforcing selective agents for this dominant defensive compound. Herbivory by red deer and capercaillie were, respectively, weakly negatively associated with δ3-carene, and strongly negatively correlated with the minor compound β-ocimene. Three of the four herbivores are probably contributory selective agents on some of the terpenes, and thus maintain some, but by no means all, of the phytochemical diversity in the species. The correlated defensive function of α-pinene against slugs and capercaillie is consistent with diffuse coevolutionary processes. PMID:21444308

  8. Quantitative characterization of clumping in Scots pine crowns

    PubMed Central

    Stenberg, Pauline; Mõttus, Matti; Rautiainen, Miina; Sievänen, Risto

    2014-01-01

    Background and Aims Proper characterization of the clumped structure of forests is needed for calculation of the absorbed radiation and photosynthetic production by a canopy. This study examined the dependency of crown-level clumping on tree size and growth conditions in Scots pine (Pinus sylvestris), and determined the ability of statistical canopy radiation models to quantify the degree of self-shading within crowns as a result of the clumping effect. Methods Twelve 3-D Scots pine trees were generated using an application of the LIGNUM model, and the crown-level clumping as quantified by the crown silhouette to total needle area ratio (STARcrown) was calculated. The results were compared with those produced by the stochastic approach of modelling tree crowns as geometric shapes filled with a random medium. Key Results Crown clumping was independent of tree height, needle area and growth conditions. The results supported the capability of the stochastic approach in characterizing clumping in crowns given that the outer shell of the tree crown is well represented. Conclusions Variation in the whole-stand clumping index is induced by differences in the spatial pattern of trees as a function of, for example, stand age rather than by changes in the degree of self-shading within individual crowns as they grow bigger. PMID:24431344

  9. Medicinal properties, in vitro protocols and secondary metabolite analyses of scots pine.

    PubMed

    Häggman, Hely; Pirttilä, Anna Maria; Niemi, Karoliina; Sarjala, Tytti; Julkunen-Tiitto, Riitta

    2009-01-01

    Scots pine (Pinus sylvestris L.) is known as an economically important forest tree with a wide distribution throughout the Northern hemisphere. Recently, the species has also become recognized as a novel source of functional food and bioactive compounds with medicinal properties. The present paper provides up-to-date information on protocols for somatic embryogenesis (i.e., the most promising in vitro method for vegetative propagation of Scots pine). Endophyte protocols cover the topics of endophyte isolation, identification and elimination from in vitro cultures. Moreover, the protocols for secondary metabolite analyses are described in order to emphasize the emerging role of Scots pine as a medicinal plant. PMID:19521833

  10. Endobacteria in some ectomycorrhiza of Scots pine (Pinus sylvestris).

    PubMed

    Izumi, Hironari; Anderson, Ian C; Alexander, Ian J; Killham, Ken; Moore, Edward R B

    2006-04-01

    The diversity of cultivable endobacteria associated with four different ectomycorrhizal morphotypes (Suillus flavidus, Suillus variegatus, Russula paludosa and Russula sp.) of Scots pine (Pinus sylvestris) was analysed by restriction fragment length polymorphism profiling of PCR-amplified rDNA intergenic spacer regions and by sequence analyses of 16S rRNA genes. Ectomycorrhizal root tip surface-sterilization methods were developed and assessed for their efficiencies. Bacterial communities from surface-sterilized ectomycorrhizal root tips were different from those of ectomycorrhizal root tips without surface-sterilization for all the morphotypes studied. Endobacteria belonging to the genera Pseudomonas, Burkholderia and Bacillus were isolated from more than one ectomycorrhizal morphotype, whereas species of Rahnella, Janthinobacterium and Rhodococcus were only isolated from the single morphotypes of S. variegatus, R. paludosa and Russula sp., respectively. Some of the isolated endobacteria utilized fungal sugars more readily than typical plant sugars in carbon utilization assays. PMID:16542403

  11. Duration of shoot elongation in Scots pine varies within the crown and between years

    PubMed Central

    Schiestl-Aalto, Pauliina; Nikinmaa, Eero; Mäkelä, Annikki

    2013-01-01

    Background and Aims Shoot elongation in boreal and temperate trees typically follows a sigmoid pattern where the onset and cessation of growth are related to accumulated effective temperature (thermal time). Previous studies on leader shoots suggest that while the maximum daily growth rate depends on the availability of resources to the shoot, the duration of the growth period may be an adaptation to long-term temperature conditions. However, other results indicate that the growth period may be longer in faster growing lateral shoots with higher availability of resources. This study investigates the interactions between the rate of elongation and the duration of the growth period in units of thermal time in lateral shoots of Scots pine (Pinus sylvestris). Methods Length development of 202 lateral shoots were measured approximately three times per week during seven growing seasons in 2–5 trees per year in a mature stand and in three trees during one growing season in a sapling stand. A dynamic shoot growth model was adapted for the analysis to determine (1) the maximum growth rate and (2) the thermal time reached at growth completion. The relationship between those two parameters and its variation between trees and years was analysed using linear mixed models. Key Results The shoots with higher maximum growth rate within a crown continued to grow for a longer period in any one year. Higher July–August temperature of the previous summer implied a higher requirement of thermal time for growth completion. Conclusions The results provide evidence that the requirement of thermal time for completion of lateral shoot extension in Scots pine may interact with resource availability to the shoot both from year to year and among shoots in a crown each year. If growing season temperatures rise in the future, this will affect not only the rate of shoot growth but its duration also. PMID:23985987

  12. Nutritional and pathogenic fungi associated with the pine engraver beetle trigger comparable defenses in Scots pine.

    PubMed

    Villari, Caterina; Battisti, Andrea; Chakraborty, Sourav; Michelozzi, Marco; Bonello, Pierluigi; Faccoli, Massimo

    2012-07-01

    Conifer bark beetles are often associated with fungal complexes whose components have different ecological roles. Some associated species are nutritionally obligate fungi, serving as nourishment to the larvae, whereas others are pathogenic blue-stain fungi known to be involved in the interaction with host defenses. In this study we characterized the local and systemic defense responses of Scots pine (Pinus sylvestris L.) against Ophiostoma brunneo-ciliatum Math. (a blue-stain pathogen) and Hyalorhinocladiella macrospora (Franke-Grosm.) Harr. (a nutritional fungus). These fungi are the principal associates of the pine engraver beetle, Ips acuminatus (Gyll.). Host responses were studied following inoculation with the fungi, singly and as a fungal complex, and by identifying and quantifying terpenoids, phenolic compounds and lignin. Although the length of the necrotic lesions differed between control (wound) and fungal treatments, only two compounds (pinosylvin monomethyl ether and (+)-α-pinene) were significantly affected by the presence of the fungi, indicating that Scots pine has a generic, rather than specific, induced response. The fact that both nutritional and blue-stain fungi triggered comparable induced defense responses suggests that even a non-pathogenic fungus may participate in exhausting host plant defenses, indirectly assisting in the beetle establishment process. Our findings contribute to the further development of current theory on the role of associated fungal complexes in bark beetle ecology. PMID:22718525

  13. Scots pine (Pinus sylvestris) bark composition and degradation by fungi: potential substrate for bioremediation.

    PubMed

    Valentín, Lara; Kluczek-Turpeinen, Beata; Willför, Stefan; Hemming, Jarl; Hatakka, Annele; Steffen, Kari; Tuomela, Marja

    2010-04-01

    The composition of Scots pine bark, its degradation, and the production of hydrolytic and ligninolytic enzymes were evaluated during 90 days of incubation with Phanerochaete velutina and Stropharia rugosoannulata. The aim was to evaluate if pine bark can be a suitable fungal substrate for bioremediation applications. The original pine bark contained 45% lignin, 25% cellulose, and 15% hemicellulose. Resin acids were the most predominant lipophilic extractives, followed by sitosterol and unsaturated fatty acids, such as linoleic and oleic acids. Both fungi degraded all main components of bark, specially cellulose (79% loss by P. velutina). During cultivation on pine bark, fungi also degraded sitosterol, produced malic acid, and oxidated unsaturated fatty acids. The most predominant enzymes produced by both fungi were cellulase and manganese peroxidase. The results indicate that Scots pine bark supports enzyme production and provides nutrients to fungi, thus pine bark may be suitable fungal substrate for bioremediation. PMID:20005699

  14. Feast and famine: previous defoliation limiting survival of pine processionary caterpillar Thaumetopoea pityocampa in Scots pine Pinus sylvestris

    NASA Astrophysics Data System (ADS)

    Hódar, José A.; Zamora, Regino; Castro, Jorge; Baraza, Elena

    2004-12-01

    This study analyses the consequences of previous defoliation on the survival of the larvae of the pine processionary moth Thaumetopoea pityocampa (Denis and Schiffermüller) feeding on relict Scots pine Pinus sylvestris (L.) ssp. nevadensis Christ in the Sierra Nevada mountains (SE Spain). Egg batches of the pine processionary moth were placed on four groups of Scots pines that underwent different periods of herbivory. The larval survival was related to the nitrogen content, fibre, phenolics and terpenes in the needles. Larval survival was higher in undefoliated pines, lower in pines defoliated two consecutive years, and intermediate in pines defoliated only one year, suggesting a direct relationship between previous defoliation and larval survival. In contrast, none of the characteristics of the needles showed a clear relationship with larval survival. The resulting reduction in larval number also affects the capacity of the larvae to develop during winter, because it hampered nest warming. Thus, previous defoliation limits, although it does not impede, the possibility of repeated defoliation on Scots pine.

  15. Tree water relations can trigger monoterpene emissions from Scots pine stems during spring recovery

    NASA Astrophysics Data System (ADS)

    Vanhatalo, A.; Chan, T.; Aalto, J.; Korhonen, J. F.; Kolari, P.; Hölttä, T.; Nikinmaa, E.; Bäck, J.

    2015-09-01

    Tree canopies are known to emit large amounts of VOCs (volatile organic compounds) such as monoterpenes into the surrounding air. High VOC emission rates from boreal forests have been observed during the transition from winter to summer activity. The most important sources of these are considered to be the green foliage, understory vegetation and soil organisms, but emissions from the living stand woody compartments have so far not been quantified. We analyzed whether the non-foliar components could partially explain the springtime high emission rates. We measured the monoterpene emissions from Scots pine (Pinus sylvestris L.) stem and shoots during the dehardening phase of trees in field conditions in two consecutive springs. We observed a large, transient monoterpene burst from the stem, while the shoot monoterpene emissions remained low. The burst lasted about 12 h. Simultaneously, an unusual nighttime sap flow and a non-systematic diurnal pattern of tree diameter were detected. Hence, we suggest that the monoterpene burst was a consequence of the recovery of the stem from wintertime, and likely related to the refilling of embolized tracheids and/or phenological changes in the living cells of the stem. This indicates that the dominant processes and environmental drivers triggering the monoterpene emissions are different between the stem and the foliage.

  16. [Specific Features of Scots Pine Seeds Formation in the Remote Period after the Chernobyl NPP Accident].

    PubMed

    Geras'kin, S A; Vasiliev, D V; Kuzmenkov, A G

    2015-01-01

    The results of long-term (2007-2011) observations on the quality of seed progeny in Scots pine populations inhabiting the sites within the Bryansk region contaminated as a result of the Chernobyl NPP accident are presented. Formed under the chronic exposure seeds are characterized by a high interannual variability, which is largely determined by weather conditions. PMID:26863784

  17. Estimating Scots Pine Tree Mortality Using High Resolution Multispectral Images

    NASA Astrophysics Data System (ADS)

    Buriak, L.; Sukhinin, A. I.; Conard, S. G.; Ivanova, G. A.; McRae, D. J.; Soja, A. J.; Okhotkina, E.

    2010-12-01

    Scots pine (Pinus sylvestris) forest stands of central Siberia are characterized by a mixed-severity fire regime that is dominated by low- to high-severity surface fires, with crown fires occurring less frequently. The purpose of this study was to link ground measurements with air-borne and satellite observations of active wildfires and older fire scars to better estimate tree mortality remotely. Data from field sampling on experimental fires and wildfires were linked with intermediate-resolution satellite (Landsat Enhanced Thematic Mapper) data to estimate fire severity and carbon emissions. Results are being applied to Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, MERIS, Landsat-ETM, SPOT (i.e., low, middle and high spatial resolution), to understand their remote-sensing capability for mapping fire severity, as indicated by tree mortality. Tree mortality depends on fireline intensity, residence time, and the physiological effects on the cambium layer, foliage and roots. We have correlated tree mortality measured after fires of varying severity with NDVI and other Chlorophyll Indexes to model tree mortality on a landscape scale. The field data obtained on experimental and wildfires are being analyzed and compared with intermediate-resolution satellite data (Landsat7-ETM) to help estimate fire severity, emissions, and carbon balance. In addition, it is being used to monitor immediate ecosystem fire effects (e.g., tree mortality) and long-term postfire vegetation recovery. These data are also being used to validate AVHRR , MODIS, and MERIS estimates of burn area. We studied burned areas in the Angara Region of central Siberia (northeast of Lake Baikal) for which both ground data and satellite data (ENVISAT-MERIS, Spot4, Landsat5, Landsat7-ETM) were available for the 2003 - 2004 and 2006 - 2008 periods. Ground validation was conducted on seventy sample plots established on burned sites differing in

  18. Moderate stress responses and specific changes in polyamine metabolism characterize Scots pine somatic embryogenesis.

    PubMed

    Salo, Heikki M; Sarjala, Tytti; Jokela, Anne; Häggman, Hely; Vuosku, Jaana

    2016-03-01

    Somatic embryogenesis (SE) is one of the methods with the highest potential for the vegetative propagation of commercially important coniferous species. However, many conifers, including Scots pine (Pinus sylvestris L.), are recalcitrant to SE and a better understanding of the mechanisms behind the SE process is needed. In Scots pine SE cultures, embryo production is commonly induced by the removal of auxin, addition of abscisic acid (ABA) and the desiccation of cell masses by polyethylene glycol (PEG). In the present study, we focus on the possible link between the induction of somatic embryo formation and cellular stress responses such as hydrogen peroxide protection, DNA repair, changes in polyamine (PA) metabolism and autophagy. Cellular PA contents and the expression of the PA metabolism genes arginine decarboxylase (ADC), spermidine synthase (SPDS), thermospermine synthase (ACL5) and diamine oxidase (DAO) were analyzed, as well as the expression of catalase (CAT), DNA repair genes (RAD51, KU80) and autophagy-related genes (ATG5, ATG8) throughout the induction of somatic embryo formation in Scots pine SE cultures. Among the embryo-producing SE lines, the expression of ADC, SPDS, ACL5, DAO, CAT, RAD51, KU80 and ATG8 showed consistent profiles. Furthermore, the overall low expression of the stress-related genes suggests that cells in those SE lines were not stressed but recognized the ABA+PEG treatment as a signal to trigger the embryogenic pathway. In those SE lines that were unable to produce embryos, cells seemed to experience the ABA+PEG treatment mostly as osmotic stress and activated a wide range of stress defense mechanisms. Altogether, our results suggest that the direction to the embryogenic pathway is connected with cellular stress responses in Scots pine SE cultures. Thus, the manipulation of stress response pathways may provide a way to enhance somatic embryo production in recalcitrant Scots pine SE lines. PMID:26786537

  19. Organic nitrogen uptake of Scots pine seedlings is independent of current carbohydrate supply.

    PubMed

    Gruffman, Linda; Palmroth, Sari; Näsholm, Torgny

    2013-06-01

    In boreal forests, seedling establishment is limited by various factors including soil nitrogen (N) availability. Seedlings may absorb N from soil in a variety of inorganic and organic forms; however, the energy and thus carbohydrate requirements for uptake and assimilation of N vary with N source. We studied the importance of current photoassimilates for the acquisition and allocation of different N sources by Scots pine (Pinus sylvestris (L.)) seedlings. Girdling was used as a tool to impair phloem transport of photoassimilates, and hence gradually deprive roots of carbohydrates. Seedlings were cultivated in a greenhouse on equimolar N concentrations of one of the N sources-arginine, ammonium or nitrate-and then girdled prior to a pulse-chase uptake experiment with isotopically labeled N sources. Girdling proved to be efficient in decreasing levels of soluble sugars and starch in the roots. Uptake rate of arginine N was highest, intermediate for ammonium N and lowest for nitrate N. Moreover, the uptake of arginine N was unaffected by girdling, while the uptake of the two inorganic N sources decreased to 45-56% of the ungirdled controls. In arginine-treated seedlings, 95-96% of the acquired arginine N resided in the roots, whereas a significant shift in the N distribution toward the shoot was evident in girdled seedlings treated with inorganic N. This spatial shift was especially pronounced in nitrate-treated seedlings suggesting that the reduction and following incorporation into roots was limited by the availability of current photoassimilates. These results suggest that there are energetic benefits for seedlings to utilize organic N sources, particularly under circumstances where carbohydrate supply is limited. Hence, these putative benefits might be of importance for the survival and growth of seedlings when carbohydrate reserves are depleted in early growing season, or in light-limited environments, such as those sustained by continuous cover forestry systems

  20. Features of Scots pine radial growth in conditions of provenance trial

    NASA Astrophysics Data System (ADS)

    Kuzmin, S.

    2012-12-01

    Provenance trial of Scots pine in Boguchany forestry of Krasnoyarsk krai is conducted on two different soils - dark-grey loam forest soil and sod-podzol sandy soil. Complex of negative factors for plant growth and development appears in dry conditions of sandy soil. It could results in decrease of resistance to diseases. Sandy soils in different climatic zones have such common traits as low absorbing capacity, poorness of elemental nutrition, low microbiological activity and moisture capacity, very high water permeability. But Scots pine trees growing in such conditions could have certain advantages and perspectives of use. In the scope of climate change (global warming) the study of Scots pine growth on sandy soil become urgent because of more frequent appearance of dry seasons. Purpose of the work is revelation of radial growth features of Scots pine with different origin in dry conditions of sandy soil and assessment of external factors influence. The main feature of radial growth of majority of studied pine provenances in conditions of sandy soil is presence of significant variation of increment with distinct decline in 25-years old with loss of tree rings in a number of cases. The reason of it is complex of factors: deficit of June precipitation and next following outbreak of fungal disease. Found «frost rings» for all trees of studied clymatypes in 1992 are the consequence of temperature decline from May 21 to June 2 - from 23 C degrees up to 2 C. Perspective climatypes with biggest radial increments and least sensitivity to fungal disease were revealed.

  1. Diverging Drought Resistance of Scots Pine Provenances Revealed by Infrared Thermography

    PubMed Central

    Seidel, Hannes; Schunk, Christian; Matiu, Michael; Menzel, Annette

    2016-01-01

    With recent climate changes, Scots pine (Pinus sylvestris L.) forests have been affected by die-off events. Assisted migration of adapted provenances mitigates drought impacts and promotes forest regeneration. Although suitable provenances are difficult to identify by traditional ecophysiological techniques, which are time consuming and invasive, plant water status can be easily assessed by infrared thermography. Thus, we examined the stress responses of 2-year-old potted Scots pine seedlings from six provenances (Bulgaria, France, Germany, Italy, Poland, and Spain) based on two thermal indices (crop water stress index and stomatal conductance index). Both indices were derived from infrared images during a 6-week drought/control treatment in a greenhouse in the summer of 2013. The pines were monitored during the stress and subsequent recovery period. After controlling for fluctuating environmental conditions, soil moisture or treatment-specific water supply was the most important driver of drought stress. The stress magnitude and response to soil water deficit depended on provenance. Under moderate drought conditions, pines from western and eastern Mediterranean provenances (Bulgaria, France, and Spain) expressed lower stress levels than those from both continental provenances (Germany and Poland). Moreover, pines from continental provenances were less resilient (showed less recovery after the stress period) than Mediterranean pines. Under extreme drought, all provenances were equally stressed with almost no significant differences in their thermal indices. Provenance-specific differences in drought resistance, which are associated with factors such as summer precipitation at the origin of Scots pine seedlings, may offer promising tracks of adaptation to future drought risks.

  2. Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine

    PubMed Central

    2014-01-01

    Background Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. Results All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Conclusions Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass. PMID:24641769

  3. Photosynthetic electron transport adjustments in overwintering Scots pine (Pinus sylvestris L.).

    PubMed

    Ivanov, A G; Sane, P V; Zeinalov, Y; Malmberg, G; Gardeström, P; Huner, N P; Oquist, G

    2001-08-01

    As shown before [C. Ottander et al. (1995) Planta 197:176-183], there is a severe inhibition of the photosystem (PS) II photochemical efficiency of Scots pine (Pinus sylvestris L.) during the winter. In contrast, the in vivo PSI photochemistry is less inhibited during winter as shown by in vivo measurements of deltaA820/A820 (P700+). There was also an enhanced cyclic electron transfer around PSI in winter-stressed needles as indicated by 4-fold faster reduction kinetics of P700+. The differential functional stability of PSII and PSI was accompanied by a 3.7-fold higher intersystem electron pool size, and a 5-fold increase in the stromal electron pool available for P700+ reduction. There was also a strong reduction of the QB band in the thermoluminescence glow curve and markedly slower Q-A re-oxidation in needles of winter pine, indicating an inhibition of electron transfer between QA and QB. The data presented indicate that the plastoquinone pool is largely reduced in winter pine, and that this reduced state is likely to be of metabolic rather than photochemical origin. The retention of PSI photochemistry, and the suggested metabolic reduction of the plastoquinone pool in winter stressed needles of Scots pine are discussed in terms of the need for enhanced photoprotection of the needles during the winter and the role of metabolically supplied energy for the recovery of photosynthesis from winter stress in evergreens. PMID:11556790

  4. Features of Scots pine radial growth in conditions of provenance trial.

    NASA Astrophysics Data System (ADS)

    Kuzmin, Sergey; Kuzmina, Nina

    2013-04-01

    Provenance trial of Scots pine in Boguchany forestry of Krasnoyarsk krai is conducted on two different soils - dark-grey loam forest soil and sod-podzol sandy soil. Complex of negative factors for plant growth and development appears in dry conditions of sandy soil. It could results in decrease of resistance to diseases. Sandy soils in different climatic zones have such common traits as low absorbing capacity, poorness of elemental nutrition, low microbiological activity and moisture capacity, very high water permeability. But Scots pine trees growing in such conditions could have certain advantages and perspectives of use. In the scope of climate change (global warming) the study of Scots pine growth on sandy soil become urgent because of more frequent appearance of dry seasons. Purpose of the work is revelation of radial growth features of Scots pine with different origin in dry conditions of sandy soil and assessment of external factors influence. The main feature of radial growth of majority of studied pine provenances in conditions of sandy soil is presence of significant variation of increment with distinct decline in 25-years old with loss of tree rings in a number of cases. The reason of it is complex of factors: deficit of June precipitation and next following outbreak of fungal disease. Found «frost rings» for all trees of studied clymatypes in 1992 are the consequence of temperature decline from May 21 to June 2 - from 23 down to 2 degree Celsius. Perspective climatypes with biggest radial increments and least sensitivity to fungal disease were revealed. Eniseysk and Vikhorevka (from Krasnoyarsk krai and Irkutsk oblast)provenances of pine have the biggest radial increments, the least sensitivity to Cenangium dieback and smallest increments decline. These climatypes are in the group of perspective provenances and in present time they are recommended for wide trial in the region for future use in plantation forest growing. Kandalaksha (Murmansk oblast

  5. Characterization of the photosynthetic apparatus in cortical bark chlorenchyma of Scots pine.

    PubMed

    Ivanov, Alexander G; Krol, Marianna; Sveshnikov, Dimitri; Malmberg, Gunilla; Gardeström, Per; Hurry, Vaughan; Oquist, Gunnar; Huner, Norman P A

    2006-05-01

    Winter-induced inhibition of photosynthesis in Scots pine (Pinus sylvestris L.) needles is accompanied by a 65% reduction of the maximum photochemical efficiency of photosystem II (PSII), measured as Fv/Fm, but relatively stable photosystem I (PSI) activity. In contrast, the photochemical efficiency of PSII in bark chlorenchyma of Scots pine twigs was shown to be well preserved, while PSI capacity was severely decreased. Low-temperature (77 K) chlorophyll fluorescence measurements also revealed lower relative fluorescence intensity emitted from PSI in bark chlorenchyma compared to needles regardless of the growing season. Nondenaturating SDS-PAGE analysis of the chlorophyll-protein complexes also revealed much lower abundance of LHCI and the CPI band related to light harvesting and the core complex of PSI, respectively, in bark chlorenchyma. These changes were associated with a 38% reduction in the total amount of chlorophyll in the bark chlorenchyma relative to winter needles, but the Chl a/b ratio and carotenoid composition were similar in the two tissues. As distinct from winter pine needles exhibiting ATP/ADP ratio of 11.3, the total adenylate content in winter bark chlorenchyma was 2.5-fold higher and the estimated ATP/ADP ratio was 20.7. The photochemical efficiency of PSII in needles attached to the twig recovered significantly faster (28-30 h) then in detached needles. Fluorescence quenching analysis revealed a high reduction state of Q(A) and the PQ-pool in the green bark tissue. The role of bark chlorenchyma and its photochemical performance during the recovery of photosynthesis from winter stress in Scots pine is discussed. PMID:16333639

  6. Mistletoe (Viscum album) infestation in the Scots pine stimulates drought-dependent oxidative damage in summer.

    PubMed

    Mutlu, Salih; Ilhan, Veli; Turkoglu, Halil Ibrahim

    2016-04-01

    This study sought to contribute to the understanding of the detrimental effect of the mistletoe (Viscum albumL.), a hemiparasitic plant, on the mortality of the Scots pine (Pinus sylvestrisL.). Fieldwork was conducted in the town of Kelkit (Gumushane province, Turkey) from April to October in 2013. Pine needles of similar ages were removed from the branches of mistletoe-infested and noninfested Scots pine plants, then transported to the laboratory and used as research materials. The effects of the mistletoe on the Scots pine during infestation were evaluated by determining the levels of water, electrolyte leakage (EL), malondialdehyde (MDA, being a product of lipid peroxidation) and reactive oxygen species (ROS) such as superoxide anion (O2 (-•)), hydrogen peroxide (H2O2) and hydroxyl radical ((•)OH). In addition, the activities of antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were measured in the same samples. The highest level of drought stress was found in summer (especially in August) as a result of the lowest water content in the soil and the highest average temperature occurring in these months. The drought stress induced by mistletoe infestation caused a regular decrease in water content, while it increased the levels of EL, MDA and ROS (H2O2, O2 (-•)and(•)OH). The infestation also stimulated the activities of CAT and POX, with the exception of SOD. On the other hand, in August, when the drought conditions were the harshest, the levels of EL and MDA, which are two of the most important indicator parameters for oxidative stress, as well as the levels of H2O2and(•)OH, which are two of the ROS leading to oxidative stress, reached the highest values in both infested and noninfested needles, whereas the O2 (-•)level decreased. For the same period and needles, CAT activity increased, while SOD activity decreased. Peroxidase activity, however, did not exhibit a significant change. Our findings indicate

  7. Influence of solar UV radiation on the nitrogen metabolism in needles of Scots pine (Pinus sylvestris L.).

    PubMed

    Krywult, Marek; Smykla, Jerzy; Kinnunen, Heli; Martz, Françoise; Sutinen, Marja-Liisa; Lakkala, Kaisa; Turunen, Minna

    2008-12-01

    Needles of 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied in an ultraviolet (UV) exclusion field experiment (from 2000 to 2002) in northern Finland (67 degrees N). The chambers held filters that excluded both UV-B and UV-A, excluded UV-B only, transmitted all UV (control), or lacked filters (ambient). UV-B/UV-A exclusion decreased nitrate reductase (NR) activity of 1-year-old needles of Scots pines compared to the controls. The proportion of free amino acids varied in the range 1.08-1.94% of total proteins, and was significantly higher in needles of saplings grown under UV-B/UV-A exclusion compared to the controls or UV-B exclusion. NR activity correlated with air temperature, indicating a "chamber effect". The study showed that both UV irradiance and increasing temperature are significant modulators of nitrogen (N) metabolism in Scots pine needles. PMID:18508165

  8. Diversity of fungi in organic soils under a moorland--Scots pine (Pinus sylvestris L.) gradient.

    PubMed

    Anderson, Ian C; Campbell, Colin D; Prosser, James I

    2003-11-01

    The conservation and regeneration of native Scots pine (Pinus sylvestris L.) woodlands is being actively encouraged by conservation agencies in the UK because of their high biodiversity value. In the present study, the consequences of regeneration on terrestrial fungal communities was determined in three parallel transects running from open moorland, through an intermediate zone showing seedling colonization, into a mature Scots pine forest at Abernethy Forest, Cairngorm, Scotland. Soil cores were taken at 18 m intervals along each 180 m transect, and the diversity of the soil fungal community was investigated by DGGE and sequence analysis of ITS fragments PCR-amplified from DNA extracted from soil. Analysis of DGGE profiles generated for two of the three transects indicates a clear shift in the community from the moorland region of the transects to the forest region. Whereas a few bands were present at all sampling points across the transects, the majority of bands were unique to either the moorland or forest samples. FASTA database searches of ITS sequence data generated from excised DGGE bands revealed the closest species match for each band. In some cases, the similarity of ITS sequences to database sequences was poor, but the remaining sequences were most closely related to ITS sequences of both mycorrhizal and non-mycorrhizal fungi. The data are discussed in relation to the effect of native pine woodland expansion on the soil fungal community. PMID:14641592

  9. Soil temperature and intermittent frost modulate the rate of recovery of photosynthesis in Scots pine under simulated spring conditions.

    PubMed

    Ensminger, Ingo; Schmidt, Lilian; Lloyd, Jon

    2008-01-01

    An earlier onset of photosynthesis in spring for boreal forest trees is predicted as the climate warms, yet the importance of soil vs air temperatures for spring recovery remains to be determined. Effects of various soil- and air-temperature conditions on spring recovery of photosynthesis in Scots pine (Pinus sylvestris) seedlings were assessed under controlled environmental conditions. Using winter-acclimated seedlings, photosynthetic responses were followed after transfer to different simulated spring conditions. Recovery rates for photosynthetic electron transport and net CO(2) uptake were slower in plants from cold or frozen soil compared with controls. In addition, a greater fraction of light absorbed was not used photochemically, but was dissipated thermally via xanthophyll cycle pigments. Intermittent frost events decreased photosynthetic capacity and increased thermal energy dissipation. Within a few days after frost events, photosynthetic capacity recovered to prefrost levels. After 18 d under spring conditions, no difference in the optimum quantum yield of photosynthesis was observed between seedlings that had been exposed to intermittent frost and control plants. These results show that, if air temperatures remain favourable and spells of subfreezing air temperatures are only of short duration, intermittent frost events delay but do not severely inhibit photosynthetic recovery in evergreen conifers during spring. Cold and/or frozen soils exert much stronger inhibitory effects on the recovery process, but they do not totally inhibit it. PMID:18181961

  10. Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances.

    PubMed

    Seidel, Hannes; Menzel, Annette

    2016-01-01

    Seedling establishment is a critical part of the life cycle, thus seedling survival might be even more important for forest persistence under recent and future climate change. Scots pine forests have been disproportionally more affected by climate change triggered forest-dieback. Nevertheless, some Scots pine provenances might prove resilient to future drought events because of the species' large distributional range, genetic diversity, and adaptation potential. However, there is a lack of knowledge on provenance-specific survival under severe drought events and on how acclimation alters survival rates in Scots pine seedlings. We therefore conducted two drought-induced mortality experiments with potted Scots pine seedlings in a greenhouse. In the first experiment, 760 three-year-old seedlings from 12 different provenances of the south-western distribution range were subjected to the same treatment followed by the mortality experiment in 2014. In the second experiment, we addressed the question of whether acclimation to re-occurring drought stress events and to elevated temperature might decrease mortality rates. Thus, 139 four-year-old seedlings from France, Germany, and Poland were subjected to different temperature regimes (2012-2014) and drought treatments (2013-2014) before the mortality experiment in 2015. Provenances clearly differed in their hazard of drought-induced mortality, which was only partly related to the climate of their origin. Drought acclimation decreased the hazard of drought-induced mortality. Above-ground dry weight and height were the main determinants for the hazard of mortality, i.e., heavier and taller seedlings were more prone to mortality. Consequently, Scots pine seedlings exhibit a considerable provenance-specific acclimation potential against drought mortality and the selection of suitable provenances might thus facilitate seedling establishment and the persistence of Scots pine forest. PMID:27458477

  11. Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances

    PubMed Central

    Seidel, Hannes; Menzel, Annette

    2016-01-01

    Seedling establishment is a critical part of the life cycle, thus seedling survival might be even more important for forest persistence under recent and future climate change. Scots pine forests have been disproportionally more affected by climate change triggered forest-dieback. Nevertheless, some Scots pine provenances might prove resilient to future drought events because of the species’ large distributional range, genetic diversity, and adaptation potential. However, there is a lack of knowledge on provenance-specific survival under severe drought events and on how acclimation alters survival rates in Scots pine seedlings. We therefore conducted two drought-induced mortality experiments with potted Scots pine seedlings in a greenhouse. In the first experiment, 760 three-year-old seedlings from 12 different provenances of the south-western distribution range were subjected to the same treatment followed by the mortality experiment in 2014. In the second experiment, we addressed the question of whether acclimation to re-occurring drought stress events and to elevated temperature might decrease mortality rates. Thus, 139 four-year-old seedlings from France, Germany, and Poland were subjected to different temperature regimes (2012–2014) and drought treatments (2013–2014) before the mortality experiment in 2015. Provenances clearly differed in their hazard of drought-induced mortality, which was only partly related to the climate of their origin. Drought acclimation decreased the hazard of drought-induced mortality. Above-ground dry weight and height were the main determinants for the hazard of mortality, i.e., heavier and taller seedlings were more prone to mortality. Consequently, Scots pine seedlings exhibit a considerable provenance-specific acclimation potential against drought mortality and the selection of suitable provenances might thus facilitate seedling establishment and the persistence of Scots pine forest. PMID:27458477

  12. Intraspecific variability in functional traits matters: case study of Scots pine.

    PubMed

    Laforest-Lapointe, Isabelle; Martínez-Vilalta, Jordi; Retana, Javier

    2014-08-01

    Although intraspecific trait variability is an important component of species ecological plasticity and niche breadth, its implications for community and functional ecology have not been thoroughly explored. We characterized the intraspecific functional trait variability of Scots pine (Pinus sylvestris) in Catalonia (NE Spain) in order to (1) compare it to the interspecific trait variability of trees in the same region, (2) explore the relationships among functional traits and the relationships between them and stand and climatic variables, and (3) study the role of functional trait variability as a determinant of radial growth. We considered five traits: wood density (WD), maximum tree height (H max), leaf nitrogen content (Nmass), specific leaf area (SLA), and leaf biomass-to-sapwood area ratio (B L:A S). A unique dataset was obtained from the Ecological and Forest Inventory of Catalonia (IEFC), including data from 406 plots. Intraspecific trait variation was substantial for all traits, with coefficients of variation ranging between 8% for WD and 24% for B L:A S. In some cases, correlations among functional traits differed from those reported across species (e.g., H max and WD were positively related, whereas SLA and Nmass were uncorrelated). Overall, our model accounted for 47% of the spatial variability in Scots pine radial growth. Our study emphasizes the hierarchy of factors that determine intraspecific variations in functional traits in Scots pine and their strong association with spatial variability in radial growth. We claim that intraspecific trait variation is an important determinant of responses of plants to changes in climate and other environmental factors, and should be included in predictive models of vegetation dynamics. PMID:24850418

  13. Cytogenetic response of Scots pine (Pinus sylvestris Linnaeus, 1753) (Pinaceae) to heavy metals

    PubMed Central

    Belousov, Mikhail Vladimirovich; Mashkina, Olga Sergeyevna; Popov, Vasily Nikolayevich

    2012-01-01

    Abstract We studied cytogenetic reactions of Scots pine seedlings to heavy metals – lead, cupric and zinc nitrates applied at concentrations 0.5 to 2000 µM. We determined the range of concentrations of heavy metals that causes mutagenic effect. Lead was found to cause the strongest genotoxicity as manifested by significant increase in the frequency of pathological mitosis, occurrence of fragmentations and agglutinations of chromosomes, various types of bridges, and a significant number of the micronuclei which were absent in the control. Possible cytogenetic mechanisms of the cytotoxic action of heavy metals are discussed. PMID:24260654

  14. Harmful effects of atmospheric nitrous acid on the physiological status of Scots pine trees.

    PubMed

    Sakugawa, Hiroshi; Cape, J Neil

    2007-06-01

    An open top chamber experiment was carried out in the summer of 2003 to examine the effect of nitrous acid (HONO) gas on the physiological status of Scots pine saplings (Pinus sylvestris). Four-year-old pine trees were exposed to two different levels of HONO gas (at ca. 2.5 ppb and 5.0 ppb) and a control (filtered air) from early evening to early morning (18:00-6:00), in duplicate open top chambers. Significant decreases in the ratios of chlorophylls a to b, an increase in the carbon to nitrogen (C/N) ratio, and a reduction of maximum yield of PS II (F(v)/F(m)) in pine needles were also observed after the 2 months' fumigation. Cation contents of pine needles were also decreased by the fumigation with HONO gas. The results could be explained by the harmful effects of OH radicals, generated from photolysis of HONO gas, and/or aqueous phase HONO (NO(2)(-)/HONO), on the photosynthetic capacity of pine needles. PMID:17400347

  15. Spatial and temporal ecology of Scots pine ectomycorrhizas.

    PubMed

    Pickles, Brian J; Genney, David R; Potts, Jacqueline M; Lennon, Jack J; Anderson, Ian C; Alexander, Ian J

    2010-05-01

    Spatial analysis was used to explore the distribution of individual species in an ectomycorrhizal (ECM) fungal community to address: whether mycorrhizas of individual ECM fungal species were patchily distributed, and at what scale; and what the causes of this patchiness might be. Ectomycorrhizas were extracted from spatially explicit samples of the surface organic horizons of a pine plantation. The number of mycorrhizas of each ECM fungal species was recorded using morphotyping combined with internal transcribed spacer (ITS) sequencing. Semivariograms, kriging and cluster analyses were used to determine both the extent and scale of spatial autocorrelation in species abundances, potential interactions between species, and change over time. The mycorrhizas of some, but not all, ECM fungal species were patchily distributed and the size of patches differed between species. The relative abundance of individual ECM fungal species and the position of patches of ectomycorrhizas changed between years. Spatial and temporal analysis revealed a dynamic ECM fungal community with many interspecific interactions taking place, despite the homogeneity of the host community. The spatial pattern of mycorrhizas was influenced by the underlying distribution of fine roots, but local root density was in turn influenced by the presence of specific fungal species. PMID:20202132

  16. Assessment of growth and stemwood quality of Scots pine on territory influenced by alkaline industrial dust.

    PubMed

    Mandre, Malle; Kask, Regino; Pikk, Jaak; Ots, Katri

    2008-03-01

    Long-term influence of alkaline dust (pH 12.3-12.7) pollution emitted over 40 years from a cement plant in Estonia was the reason of alkalisation (pH 6.7-7.9) and high concentrations of K, Ca and Mg in the soil of affected territories. Although dust emission has diminished during the last 10 years, the imbalances in nutrition substrate and their influence on the growth of trees are notable up to now. The study of morphological and physical properties of 70-80-year-old Scots pine (Pinus sylvestris L.) crown, stems and stemwood from three different air pollution zones showed serious deviations in comparison with a relatively healthy forest in an unpolluted area. The specimens from polluted trees, if compared to reference site, showed significantly smaller height growth, radial increment and width of annual rings of sapwood. In heartwood wider annual rings were found in polluted areas. In the period of heartwood formation the dust pollution level emitted from the plant was relatively modest and cement dust, which contains elements necessary for mineral nutrition of trees, may have acted as fertiliser. The moisture content in sapwood and heartwood, especially in the upper layers of stems, was lower in the polluted area than in reference site trees. Regression analysis revealed a strong dependence between latewood percentage and sapwood or heartwood in stems of Scots pine in all sample plots. PMID:17508259

  17. Analysis and simulation of dynamic response behavior of Scots pine trees to wind loading.

    PubMed

    Schindler, Dirk; Fugmann, Hannes; Mayer, Helmut

    2013-11-01

    This paper presents an empirical approach for the decomposition, simulation, and reconstruction of wind-induced stem displacement of plantation-grown Scots pine trees. Results from singular spectrum analysis (SSA) allow a low-dimensional characterization of the complex and complicated tree motion patterns in response to non-destructive wind excitation. Since motion of the sample trees was dominated by sway in the first mode, the application of SSA on time series of sample trees' stem displacement yielded characteristic and distinguishable non-oscillatory trend components, quasi-oscillatory sway, and noise, of which only the non-oscillatory components were correlated directly with wind characteristics. Although sway in the range of the dominant damped fundamental frequency dominated the measured stem displacement signals, it was almost decoupled from near-surface airflow. The ability to discriminate SSA-components is demonstrated based on correlation and spectral analysis. These SSA-components, as well as wind speed measured in the canopy space of the Scots pine forest, were used to train neural networks, which could then reasonably simulate tree response to wind excitation. PMID:23196785

  18. Effects of a long-term heavy-metal pollution on Scots pine forests

    NASA Astrophysics Data System (ADS)

    Nieminen, T. M.

    2003-05-01

    The major source of Cu and Ni emissions in Finland is a Cu-Ni smelter at Harjavalta. The mean, lO-year Cu:Ni ratio of emissions derived from smelting activities is about 3:1. However, the corresponding ratio in the organic layer in an adjacent Scots pine stand is 12:1, suggesting that Cu is retained more efficiently than Ni in the surface soil. The experimentally estimated rate of Cu uptake by the roots of pine seedlings cultivated in smelterpolluted soil was higher than the corresponding Ni uptake rate, but Ni transport from the roots to the shoot was more efficient than that of Cu. This is in agreement with an exposure experiment in which the lethal metal threshold in pine roots was found to be much lower for Ni (less than 100 mg kg^{-1}) than for Cu (less than 1000 mg kg^{-1}). The overall metal uptake rates of the pine seedlings were relatively low and had no reducing effect on the metal concentrations in the soil.

  19. A Functional and Structural Mongolian Scots Pine (Pinus sylvestris var. mongolica) Model Integrating Architecture, Biomass and Effects of Precipitation

    PubMed Central

    Wang, Feng; Letort, Véronique; Lu, Qi; Bai, Xuefeng; Guo, Yan; de Reffye, Philippe; Li, Baoguo

    2012-01-01

    Mongolian Scots pine (Pinus sylvestris var. mongolica) is one of the principal tree species in the network of Three-North Shelterbelt for windbreak and sand stabilisation in China. The functions of shelterbelts are highly correlated with the architecture and eco-physiological processes of individual tree. Thus, model-assisted analysis of canopy architecture and function dynamic in Mongolian Scots pine is of value for better understanding its role and behaviour within shelterbelt ecosystems in these arid and semiarid regions. We present here a single-tree functional and structural model, derived from the GreenLab model, which is adapted for young Mongolian Scots pines by incorporation of plant biomass production, allocation, allometric rules and soil water dynamics. The model is calibrated and validated based on experimental measurements taken on Mongolian Scots pines in 2007 and 2006 under local meteorological conditions. Measurements include plant biomass, topology and geometry, as well as soil attributes and standard meteorological data. After calibration, the model allows reconstruction of three-dimensional (3D) canopy architecture and biomass dynamics for trees from one- to six-year-old at the same site using meteorological data for the six years from 2001 to 2006. Sensitivity analysis indicates that rainfall variation has more influence on biomass increment than on architecture, and the internode and needle compartments and the aboveground biomass respond linearly to increases in precipitation. Sensitivity analysis also shows that the balance between internode and needle growth varies only slightly within the range of precipitations considered here. The model is expected to be used to investigate the growth of Mongolian Scots pines in other regions with different soils and climates. PMID:22927982

  20. A functional and structural Mongolian Scots pine (Pinus sylvestris var. mongolica) model integrating architecture, biomass and effects of precipitation.

    PubMed

    Wang, Feng; Letort, Véronique; Lu, Qi; Bai, Xuefeng; Guo, Yan; de Reffye, Philippe; Li, Baoguo

    2012-01-01

    Mongolian Scots pine (Pinus sylvestris var. mongolica) is one of the principal tree species in the network of Three-North Shelterbelt for windbreak and sand stabilisation in China. The functions of shelterbelts are highly correlated with the architecture and eco-physiological processes of individual tree. Thus, model-assisted analysis of canopy architecture and function dynamic in Mongolian Scots pine is of value for better understanding its role and behaviour within shelterbelt ecosystems in these arid and semiarid regions. We present here a single-tree functional and structural model, derived from the GreenLab model, which is adapted for young Mongolian Scots pines by incorporation of plant biomass production, allocation, allometric rules and soil water dynamics. The model is calibrated and validated based on experimental measurements taken on Mongolian Scots pines in 2007 and 2006 under local meteorological conditions. Measurements include plant biomass, topology and geometry, as well as soil attributes and standard meteorological data. After calibration, the model allows reconstruction of three-dimensional (3D) canopy architecture and biomass dynamics for trees from one- to six-year-old at the same site using meteorological data for the six years from 2001 to 2006. Sensitivity analysis indicates that rainfall variation has more influence on biomass increment than on architecture, and the internode and needle compartments and the aboveground biomass respond linearly to increases in precipitation. Sensitivity analysis also shows that the balance between internode and needle growth varies only slightly within the range of precipitations considered here. The model is expected to be used to investigate the growth of Mongolian Scots pines in other regions with different soils and climates. PMID:22927982

  1. A mycobacterium isolated from tissue cultures of mature Pinus sylvestris interferes with growth of Scots pine seedlings.

    PubMed

    Laukkanen, H; Soini, H; Kontunen-Soppela, S; Hohtola, A; Viljanen, M

    2000-07-01

    We isolated a rapidly growing, pigment-producing mycobacterium from senescent tissue cultures derived from mature Scots pine (Pinus sylvestris L.). The bacterium was found in three senescent suspension cultures and in a senescent protoplast culture. Growth of Scots pine cells had ceased in all of these cultures. Exogenous contamination was eliminated by rigorous surface sterilization of the buds with hypochlorite before aseptic removal of the bud scales. Based on biochemical and physiological properties and DNA sequence comparisons, the isolated mycobacterium did not belong to any known species. Its sequence most closely resembled those of Mycobacterium obuense (97%) and M. aichiense (96%). Tissue browning was frequently observed in callus or suspension culture of Scots pine. Because the effect of the mycobacterium on growth of undifferentiated tissues that were browning was difficult to evaluate, we applied the bacterium to Scots pine seeds in aseptic conditions. Seedlings grown in the presence of the mycobacterium had shorter hypocotyls than control seedlings and seedlings cocultivated with a Pseudomonas strain known to be harmless to plants. However, hypocotyl growth of seedlings cocultivated with another mycobacterium, M. chlorophenolicum, was similar to that observed in the presence of the isolated mycobacterium. Phenylalanine ammonia-lyase activity of seedlings cocultivated with the mycobacterium isolate was significantly higher than that of control seedlings or seedlings cocultivated with M. chlorophenolicum or Pseudomotnas fluorescens. We believe that this is the first report of the isolation of mycobacteria from tissue cultures of a tree. Our finding that the mycobacterium may interfere with the growth of Scots pine in vitro warrants further study. PMID:11303582

  2. Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

    NASA Astrophysics Data System (ADS)

    Rantala, P.; Aalto, J.; Taipale, R.; Ruuskanen, T. M.; Rinne, J.

    2015-06-01

    Long-term flux measurements of volatile organic compounds (VOC) over boreal forests are rare, although the forests are known to emit considerable amounts of VOCs into the atmosphere. Thus, we measured fluxes of several VOCs and oxygenated VOCs over a Scots pine dominated boreal forest semi-continuously between May 2010 and December 2013. The VOC profiles were obtained with a proton-transfer-reaction mass-spectrometry, and the fluxes were calculated using vertical concentration profiles and the surface layer profile method connected to the Monin-Obukhov similarity theory. In total fluxes that differed significantly from zero on a monthly basis were observed for 14 out 27 measured masses. Monoterpenes had the highest net emission in all seasons and statistically significant positive fluxes were detected from March until November. Other important compounds emitted were methanol, ethanol/formic acid, acetone and isoprene/MBO. Oxygenated VOCs showed also deposition fluxes that were statistically different from zero. Isoprene/methylbutenol and monoterpene fluxes followed well the traditional isoprene algorithm and the hybrid algorithm, respectively. Emission potentials of monoterpenes were largest in late spring and fall which was possibly driven by growth processes and decaying of soil litter, respectively. Conversely, largest emission potentials of isoprene/methylbutenol were found in July. Thus, we concluded that most of the emissions of m/z 69 at the site consisted of isoprene that originated from broadleaved trees. Methanol had deposition fluxes especially before sunrise. This can be connected to water films on surfaces. Based on this assumption, we were able to build an empirical algorithm for bi-directional methanol exchange that described both emission term and deposition term. Methanol emissions were highest in May and June and deposition level increased towards fall, probably as a result of increasing relative humidity levels leading to predominance of

  3. Annual cycle of volatile organic compound exchange between a boreal pine forest and the atmosphere

    NASA Astrophysics Data System (ADS)

    Rantala, P.; Aalto, J.; Taipale, R.; Ruuskanen, T. M.; Rinne, J.

    2015-10-01

    Long-term flux measurements of volatile organic compounds (VOC) over boreal forests are rare, although the forests are known to emit considerable amounts of VOCs into the atmosphere. Thus, we measured fluxes of several VOCs and oxygenated VOCs over a Scots-pine-dominated boreal forest semi-continuously between May 2010 and December 2013. The VOC profiles were obtained with a proton transfer reaction mass spectrometry, and the fluxes were calculated using vertical concentration profiles and the surface layer profile method connected to the Monin-Obukhov similarity theory. In total fluxes that differed significantly from zero on a monthly basis were observed for 13 out of 27 measured masses. Monoterpenes had the highest net emission in all seasons and statistically significant positive fluxes were detected from March until October. Other important compounds emitted were methanol, ethanol+formic acid, acetone and isoprene+methylbutenol. Oxygenated VOCs showed also deposition fluxes that were statistically different from zero. Isoprene+methylbutenol and monoterpene fluxes followed well the traditional isoprene algorithm and the hybrid algorithm, respectively. Emission potentials of monoterpenes were largest in late spring and autumn which was possibly driven by growth processes and decaying of soil litter, respectively. Conversely, largest emission potentials of isoprene+methylbutenol were found in July. Thus, we concluded that most of the emissions of m/z 69 at the site consisted of isoprene that originated from broadleaved trees. Methanol had deposition fluxes especially before sunrise. This can be connected to water films on surfaces. Based on this assumption, we were able to build an empirical algorithm for bi-directional methanol exchange that described both emission term and deposition term. Methanol emissions were highest in May and June and deposition level increased towards autumn, probably as a result of increasing relative humidity levels leading to

  4. Influence of tree provenance on biogenic VOC emissions of Scots pine (Pinus sylvestris) stumps

    NASA Astrophysics Data System (ADS)

    Kivimäenpää, Minna; Magsarjav, Narantsetseg; Ghimire, Rajendra; Markkanen, Juha-Matti; Heijari, Juha; Vuorinen, Martti; Holopainen, Jarmo K.

    2012-12-01

    Resin-storing plant species such as conifer trees can release substantial amounts of volatile organic compounds (VOCs) into the atmosphere under stress circumstances that cause resin flow. Wounding can be induced by animals, pathogens, wind or direct mechanical damage e.g. during harvesting. In atmospheric modelling of biogenic VOCs, actively growing vegetation has been mostly considered as the source of emissions. Root systems and stumps of resin-storing conifer trees could constitute a significant store of resin after tree cutting. Therefore, we assessed the VOC emission rates from the cut surface of Scots pine stumps and estimated the average emission rates for an area with a density of 2000 stumps per ha. The experiment was conducted with trees of one Estonian and three Finnish Scots pine provenances covering a 1200 km gradient at a common garden established in central Finland in 1991. VOC emissions were dominated by monoterpenes and less than 0.1% of the total emission was sesquiterpenes. α-Pinene (7-92% of the total emissions) and 3-carene (0-76% of the total emissions) were the dominant monoterpenes. Proportions of α-pinene and camphene were significantly lower and proportions of 3-carene, sabinene, γ-terpinene and terpinolene higher in the southernmost Saaremaa provenance compared to the other provenances. Total terpene emission rates (standardised to +20 °C) from stumps varied from 27 to 1582 mg h-1 m-2 when measured within 2-3 h after tree cutting. Emission rates decreased rapidly to between 2 and 79 mg h-1 m-2 at 50 days after cutting. The estimated daily terpene emission rates on a hectare basis from freshly cut stumps at a cut tree density of 2000 per ha varied depending on provenance. Estimated emission ranges were 100-710 g ha-1 d-1 and 137-970 g ha-1 d-1 in 40 and in 60 year-old forest stands, respectively. Our result suggests that emission directly from stump surfaces could be a significant source of monoterpene emissions for a few weeks after

  5. Dynamics of leaf gas exchange, chlorophyll fluorescence and stem diameter changes during freezing and thawing of Scots pine seedlings.

    PubMed

    Lindfors, Lauri; Hölttä, Teemu; Lintunen, Anna; Porcar-Castell, Albert; Nikinmaa, Eero; Juurola, Eija

    2015-12-01

    Boreal trees experience repeated freeze-thaw cycles annually. While freezing has been extensively studied in trees, the dynamic responses occurring during the freezing and thawing remain poorly understood. At freezing and thawing, rapid changes take place in the water relations of living cells in needles and in stem. While freezing is mostly limited to extracellular spaces, living cells dehydrate, shrink and their osmotic concentration increases. We studied how the freezing-thawing dynamics reflected on leaf gas exchange, chlorophyll fluorescence and xylem and living bark diameter changes of Scots pine (Pinus sylvestris L.) saplings in controlled experiments. Photosynthetic rate quickly declined following ice nucleation and extracellular freezing in xylem and needles, almost parallel to a rapid shrinking of xylem diameter, while that of living bark followed with a slightly longer delay. While xylem and living bark diameters responded well to decreasing temperature and water potential of ice, the relationship was less consistent in the case of increasing temperature. Xylem showed strong temporal swelling at thawing suggesting water movement from bark. After thawing xylem diameter recovered to a pre-freezing level but living bark remained shrunk. We found that freezing affected photosynthesis at multiple levels. The distinct dynamics of photosynthetic rate and stomatal conductance reveals that the decreased photosynthetic rate reflects impaired dark reactions rather than stomatal closure. Freezing also inhibited the capacity of the light reactions to dissipate excess energy as heat, via non-photochemical quenching, whereas photochemical quenching of excitation energy decreased gradually with temperature in agreement with the gas exchange data. PMID:26423334

  6. Canopy Defoliation has More Impact on Carbohydrate Availability than on Hydraulic Function in Declining Scots Pine Populations

    NASA Astrophysics Data System (ADS)

    Poyatos, R.; Aguadé, D.; Gómez, M.; Mencuccini, M.; Martínez-Vilalta, J.

    2013-12-01

    Drought-induced defoliation has recently been associated with depletion of carbohydrate reserves and increased mortality risk in Scots pine (Pinus sylvestris L.) at its dry limit. Are defoliated pines hydraulically impaired compared to non-defoliated pines? Moreover, how do defoliated pines cope with potentially lethal droughts, as compared to non-defoliated pines in the same population? In order to address these questions, we measured the seasonal dynamics of sap flow and needle water potentials (2010-2012), hydraulic function and non-structural carbohydrates (NSC) (2012) in healthy and defoliated pines in the Prades mountains (NE Spain). The summer drought was mild in 2010, intense in 2012 and extremely long in 2011. Defoliated Scots pines showed higher sap flow per unit leaf area during spring, but they were more sensitive to summer drought (Figure 1). This pattern was associated with a steeper decline in soil-to-leaf hydraulic conductance, which could not be explained by differences in branch vulnerability to embolism across defoliation classes. Accordingly, the native loss of xylem conductivity in branches, measured in 2012, remained similar across defoliation classes and reached >65% at the peak of the drought. However, a steeper vulnerability curve was observed for root xylem of defoliated pines. Xylem diameter variations (2011-2012) will be used to further investigate possible differences in the aboveground/belowground partitioning of hydraulic resistance across defoliation classes. NSC levels varied across tree organs (leaves>branches>roots>trunk) and strongly declined with drought. Defoliated pines displayed reduced NSC levels throughout the study period, despite enhanced water transport capacity and increased gas exchange rates during spring. Overall, the defoliated vs. healthy status seems to be more associated to differences in carbohydrate storage and dynamics than to hydraulic differences per se. However, starch conversion to soluble sugars during

  7. Characterization of Scots pine stump-root biomass as feed-stock for gasification.

    PubMed

    Eriksson, Daniel; Weiland, Fredrik; Hedman, Henry; Stenberg, Martin; Öhrman, Olov; Lestander, Torbjörn A; Bergsten, Urban; Öhman, Marcus

    2012-01-01

    The main objective was to explore the potential for gasifying Scots pine stump-root biomass (SRB). Washed thin roots, coarse roots, stump heartwood and stump sapwood were characterized (solid wood, milling and powder characteristics) before and during industrial processing. Non-slagging gasification of the SRB fuels and a reference stem wood was successful, and the gasification parameters (synthesis gas and bottom ash characteristics) were similar. However, the heartwood fuel had high levels of extractives (≈19%) compared to the other fuels (2-8%) and thereby ≈16% higher energy contents but caused disturbances during milling, storage, feeding and gasification. SRB fuels could be sorted automatically according to their extractives and moisture contents using near-infrared spectroscopy, and their amounts and quality in forests can be predicted using routinely collected stand data, biomass functions and drill core analyses. Thus, SRB gasification has great potential and the proposed characterizations exploit it. PMID:22130078

  8. Fungal Infection Increases the Rate of Somatic Mutation in Scots Pine (Pinus sylvestris L.).

    PubMed

    Ranade, Sonali Sachin; Ganea, Laura-Stefana; Razzak, Abdur M; García Gil, M R

    2015-01-01

    Somatic mutations are transmitted during mitosis in developing somatic tissue. Somatic cells bearing the mutations can develop into reproductive (germ) cells and the somatic mutations are then passed on to the next generation of plants. Somatic mutations are a source of variation essential to evolve new defense strategies and adapt to the environment. Stem rust disease in Scots pine has a negative effect on wood quality, and thus adversely affects the economy. It is caused by the 2 most destructive fungal species in Scandinavia: Peridermium pini and Cronartium flaccidum. We studied nuclear genome stability in Scots pine under biotic stress (fungus-infected, 22 trees) compared to a control population (plantation, 20 trees). Stability was assessed as accumulation of new somatic mutations in 10 microsatellite loci selected for genotyping. Microsatellites are widely used as molecular markers in population genetics studies of plants, and are particularly used for detection of somatic mutations as their rate of mutation is of a much higher magnitude when compared with other DNA markers. We report double the rate of somatic mutation per locus in the fungus-infected trees (4.8×10(-3) mutations per locus), as compared to the controls (2.0×10(-3) mutations per locus) when individual samples were analyzed at 10 different microsatellite markers. Pearson's chi-squared test indicated a significant effect of the fungal infection which increased the number of mutations in the fungus-infected trees (χ(2) = 12.9883, df = 1, P = 0.0003134). PMID:25890976

  9. Climatic factors and reindeer grazing -- the effects on soil carbon dynamics in subarctic boreal pine forest.

    NASA Astrophysics Data System (ADS)

    Köster, Kajar; Köster, Egle; Berninger, Frank; Pumpanen, Jukka

    2016-04-01

    Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in the northern ecosystems, affecting plant diversity, soil nutrient cycling and soil organic matter decomposition. Changes caused by reindeer in vegetation have indirect effects on physical features of the soil e.g. soil microclimate, root biomass and also on soil carbon dynamics. In a field experiment in Finnish Lapland, Värriö Strict Nature Reserve (67° 46' N, 29° 35' E) we investigated how the reindeer grazing in subarctic boreal forest combined with climate (air temperature and precipitation) affects soil temperature, soil water content, and ultimately the CO2 efflux from forest soils. The study was carried out in the growing seasons of the years 2013 and 2014, where 2013 was an extremely dry year (specially the summer), and the year 2014 was a "normal" year in means of precipitations. Our study areas are located in the northern boreal subarctic coniferous forest at the zone of the last intact forest landscapes in Fennoscandia, where large areas of relatively undisturbed subarctic Scots pine (Pinus sylvestris L.) forests can still be found. We established the experiment as a split plot experiment with 2 blocks and 5 sub-plots per treatment that were divided into grazed and non-grazed parts, separated with a fence. The sample plots are located along the borderline between Finland and Russia, where the ungrazed area was excluded from reindeer already in 1918, to prevent the Finnish reindeer from going to the Russian side and there are not many reindeer on Russian side of the area. Our study showed that in subarctic mature pine forests, soil temperatures were higher, and soil water content was fluctuating more on grazed areas compared to non-grazed areas in both years. In both years, the soil water content on the grazed area was highest in June. The situation changed somewhere in the second half of July when the moisture content in the non-grazed area was higher. We found

  10. Changes in bryophyte and lichen communities on Scots pines along an alkaline dust pollution gradient.

    PubMed

    Degtjarenko, Polina; Marmor, Liis; Randlane, Tiina

    2016-09-01

    Dust pollution can cause a significant damage of environment and endanger human health. Our study aimed to investigate epiphytic lichens and bryophytes in relation to long-term alkaline dust pollution and provide new insights into the bioindicators of dust pollution. We measured the bark pH of Scots pines and the species richness and cover of two cryptogam groups in 32 sample plots in the vicinity of limestone quarries (up to ca. 3 km) in northern Estonia. The bark pH decreased gradually with increasing distance from quarries. We recorded the changes in natural epiphytic communities, resulting in diversified artificial communities on pines near the pollution source; the distance over 2 km from the quarries was sufficient to re-establish the normal acidity of the bark and natural communities of both lichens and bryophytes. The cover of lichens and the number of bryophytes are a more promising indicator of environmental conditions than individual species occurrence. We confirmed previously proposed and suggested new bioindicator species of dust pollution (e.g., Lecidella elaeochroma, Opegrapha varia, Schistidium apocarpum). Limestone quarrying activity revealed a "parapositive" impact on cryptogamic communities, meaning that quarrying might, besides disturbances of natural communities, temporarily contribute to the distribution of locally rare species. PMID:27230146

  11. Growth responses of Scots pine to climatic factors on reclaimed oil shale mined land.

    PubMed

    Metslaid, Sandra; Stanturf, John A; Hordo, Maris; Korjus, Henn; Laarmann, Diana; Kiviste, Andres

    2016-07-01

    Afforestation on reclaimed mining areas has high ecological and economic importance. However, ecosystems established on post-mining substrate can become vulnerable due to climate variability. We used tree-ring data and dendrochronological techniques to study the relationship between climate variables and annual growth of Scots pine (Pinus sylvestris L.) growing on reclaimed open cast oil shale mining areas in Northeast Estonia. Chronologies for trees of different age classes (50, 40, 30) were developed. Pearson's correlation analysis between radial growth indices and monthly climate variables revealed that precipitation in June-July and higher mean temperatures in spring season enhanced radial growth of pine plantations, while higher than average temperatures in summer months inhibited wood production. Sensitivity of radial increment to climatic factors on post-mining soils was not homogenous among the studied populations. Older trees growing on more developed soils were more sensitive to precipitation deficit in summer, while growth indices of two other stand groups (young and middle-aged) were highly correlated to temperature. High mean temperatures in August were negatively related to annual wood production in all trees, while trees in the youngest stands benefited from warmer temperatures in January. As a response to thinning, mean annual basal area increment increased up to 50 %. By managing tree competition in the closed-canopy stands, through the thinning activities, tree sensitivity and response to climate could be manipulated. PMID:26573311

  12. Effects of drought and irrigation on ecosystem functioning in a mature Scots pine forest

    NASA Astrophysics Data System (ADS)

    Dobbertin, Matthias; Brunner, Ivano; Egli, Simon; Eilmann, Britta; Graf Pannatier, Eisabeth; Schleppi, Patrick; Zingg, Andreas; Rigling, Andreas

    2010-05-01

    Climate change is expected to increase temperature and reduce summer precipitation in Switzerland. To study the expected effects of increased drought in mature forests two different approaches are in general possible: water can be partially or completely removed from the ecosystems via above- or below-canopy roofs or water can be added to already drought-prone ecosystems. Both methods have advantages and disadvantages. In our study water was added to a mature 90-year old Scots pine (Pinus sylvestris L.) forest with a few singe pubescent oaks (Quercus pubescens Willd.), located in the valley bottom of the driest region of Switzerland (Valais). In Valais, Scots pines are declining, usually with increased mortality rates following drought years. It was therefore of special interest to study here how water addition is changing forest ecosystem functioning. The irrigation experiment started in the summer of 2003. Out of eight 0.1 ha experimental plots, four were randomly selected for irrigation, the other four left as a control. Irrigation occurred during rainless nights between April and October, doubling the annual rainfall amount from 650 to 1300 mm. Irrigation water, taken from a near-by irrigation channel, added some nutrients to the plots, but nutrients which were deficient on the site, e.g. nitrogen and phosphorus, were not altered. Tree diameter, tree height and crown width were assessed before the start of the irrigation in winter 2002/2003 and after 7 years of the experiment in 2009/2010. Tree crown transparency (lack of foliage) and leaf area index (LAI) were annually assessed. Additionally, tree mortality was annually evaluated. Mycorrhizal fruit bodies were identified and counted at weekly intervals from 2003 until 2007. Root samples were taken in 2004 and 2005. In 2004 and 2005 wood formation of thirteen trees was analysed in weekly or biweekly intervals using the pinning method. These trees were felled in 2006 for stem, shoot and needle growth analysis

  13. Water availability influences morphology, mycorrhizal associations, PSII efficiency and polyamine metabolism at early growth phase of Scots pine seedlings.

    PubMed

    Muilu-Mäkelä, Riina; Vuosku, Jaana; Läärä, Esa; Saarinen, Markku; Heiskanen, Juha; Häggman, Hely; Sarjala, Tytti

    2015-03-01

    Scots pine (Pinus sylvestris L.) is adapted to various soil types with diverse water availabilities. However, Scots pine seedlings are vulnerable to abiotic stress during the early growth, when they may be exposed to both dry and wet conditions. Here, we focused on the above and below ground coping strategies of Scots pine seedlings under controlled wet, optimal and dry soil conditions by investigating morphological traits including seedling biomass, number of root tips, proportion of mycorrhizal root tips and brown needles. In addition, we studied metabolic and physiological responses including gene expression involved in biosynthesis and catabolism of polyamines (PA), PSII efficiency and the expression of the catalase (CAT) late-embryogenesis abundant protein (LEA), pyruvate decarboxylase (PDC), glutamate-cysteine ligase (GCL) and glutathione synthetase (GS) genes. We found that seedlings invested in shoots by maintaining stable shoot water content and high PSII efficiency under drought stress. Free and soluble conjugated putrescine (Put) accumulated in needles under drought stress, suggesting the role of Put in protection of photosynthesizing tissues. However, the expression of the PA biosynthesis genes, arginine decarboxylase (ADC), spermidine synthase (SPDS) and thermospermine synthase (ACL5) was not affected under drought stress whereas catabolizing genes diamino oxidase (DAO) and polyamine oxidase (PAO) were down-regulated in shoots. The morphology of the roots was affected by peat water content. Furthermore, both drought stress and water excess restricted the seedling ability to sustain a symbiotic relationship. The consistent pattern of endogenous PAs seems to be advantageous to the Scots pine seedlings also under stress conditions. PMID:25666263

  14. Scots pine bark, topsoil and pedofauna as indicators of transport pollutions in terrestrial ecosystems.

    PubMed

    Marko-Worłowska, Maria; Chrzan, Anna; Łaciak, Tomasz

    2011-01-01

    The impact of the motorway on pollution was evaluated by determining chosen heavy metals and acid reaction (pH) in the pine bark, in forest and meadow topsoil. The content of these environmental contaminants was determined in the topsoil and in the bark of around 40 year-old Scots pines (Pinus sylvestris L.) growing right next to the soil analyzed. The pollutants were examined at localities situated around 5, 200, 1500 m away from the motorway. To evaluate influence of Cd, Pb, Zn, Cu and the topsoil pH on pedofauna, five meadows localities situated 1, 20, 40, 150, 1550 m away from the motorway were examined. It was detected that in the forest habitats analyzed the bark was characterized by considerably higher acidity (pH 3.14-3.88) than the topsoil of the pines analyzed (pH 5.45-7.22). Except of Cd at locality 200 m and Cu at 1500 m from motorway, the higher concentration of heavy metals was noted in topsoil. In the meadow soil of the locality 150 m from the motorway the highest concentrations of Cd and Zn were detected. The greatest diversity of the meso and macrofauna and trophic relations the most resembling natural were detected in the area furthest away from the motorway, where the content of the heavy metals was the lowest. The lowest density and diversity of meso- and macrofauna were detected in the area situated 40 m, where the concentration of heavy metals was higher than at 1, 20 and 1550 m from the motorway situated localities. PMID:21170775

  15. Toxic effects of cadmium and zinc on ectomycorrhizal colonization of Scots pine (Pinus sylvestris L.) from soil inoculum

    SciTech Connect

    Hartley-Whitaker, J.; Cairney, J.W.G.; Meharg, A.A.

    2000-03-01

    Scots pine seedlings colonized by ectomycorrhizal (ECM) fungi from natural soil inoculum were exposed to a range of Cd or Zn concentrations to investigate the effects of metals on ECM fungi-Scots pine associations in a realistic soil environment. Experiments focused on the relationship between the sensitivity of ECM fungi and their host plants, the influence of metals on ECM community dynamics on Scots pine roots, and the effects of metal exposure on ECM colonization from soil-borne propagules. Ectomycorrhizal colonization was inhibited by Cd and Zn, with a decrease in the proportion of ECM-colonized root tips. Shoot and root biomass, total root length, and total root-tip density, however, were unaffected by Cd or Zn. A decrease in the diversity of ECM morphotypes also occurred, which could have a negative effect on tree vigor. Overall, colonization by ECM fungi was more sensitive than seedling growth to Cd and Zn, and this could have serious implications for successful tree establishment on metal-contaminated soils.

  16. Estimation of scots pine defoliation by the common pine sawfly (Diprion pini L.) using multi-temporal radar data

    NASA Astrophysics Data System (ADS)

    Latva-Kayra, Petri T.

    In 1998-2001 Finland suffered the most severe insect outbreak ever recorded, over 500,000 hectares. The outbreak was caused by the common pine sawfly ( Diprion pini L.). The outbreak has continued in the study area, Palokangas, ever since. To find a good method to monitor this type of outbreaks, the purpose of this study was to examine the efficacy of multi-temporal ERS-2 and ENVISAT SAR imagery for estimating Scots pine (Pinus sylvestris L.) defoliation. Three methods were tested: unsupervised k-means clustering, supervised linear discriminant analysis (LDA) and logistic regression. In addition, I assessed if harvested areas could be differentiated from the defoliated forest using the same methods. Two different speckle filters were used to determine the effect of filtering on the SAR imagery and subsequent results. The logistic regression performed best, producing a classification accuracy of 81.6% (kappa 0.62) with two classes (no defoliation, >20% defoliation). LDA accuracy was with two classes at best 77.7% (kappa 0.54) and k-means 72.8 (0.46). In general, the largest speckle filter, 5 x 5 image window, performed best. When additional classes were added the accuracy was usually degraded on a step-by-step basis. The results were good, but because of the restrictions in the study they should be confirmed with independent data, before full conclusions can be made that results are reliable. The restrictions include the small size field data and, thus, the problems with accuracy assessment (no separate testing data) as well as the lack of meteorological data from the imaging dates.

  17. Frost hardiness of mycorrhizal and non-mycorrhizal Scots pine under two fertilization treatments.

    PubMed

    Korhonen, Anna; Lehto, Tarja; Repo, Tapani

    2015-07-01

    Survival and functioning of mycorrhizal associations at low temperatures are not known well. In an earlier study, ectomycorrhizas did not affect the frost hardiness of Scots pine (Pinus sylvestris L.) roots, but here we studied whether differential nutrient availability would change the result and additionally, alter frost hardiness aboveground. The aim in this experiment was to compare the frost hardiness of roots and needles of mycorrhizal (Hebeloma sp.) and non-mycorrhizal Scots pine seedlings raised using two fertilization treatments and two cold-hardening regimes. The fertilization treatments were low (LF) and high (HF) application of a complete nutrient solution. Three hundred mycorrhizal and non-mycorrhizal seedlings were cultivated in growth chambers in four blocks for 16 weeks. For the first 9 weeks, the seedlings grew in long-day and high-temperature (LDHT) with low fertilization and then they were raised for 3 weeks in LDHT with either low or high fertilization. After this, half of the plants in each treatment combination remained in LDHT, and half were transferred to short-day and low-temperature (SDLT) conditions to cold acclimatize. The frost hardiness of the roots and needles was assessed using controlled freezing tests followed by electrolyte leakage tests (REL). Mycorrhizal roots were slightly more frost hardy than non-mycorrhizal roots, but only in the growing-season conditions (LDHT) in low-nutrient treatment. In LDHT and LF, the frost hardiness of the non-mycorrhizal roots was about -9 °C, and that of the non-mycorrhizal HF roots and the mycorrhizal roots in both fertilization levels was about -11 °C. However, no difference was found in the roots within the SDLT regime, and in needles, there was no difference between mycorrhizal and fertilization treatments. The frost hardiness of needles increased by SDLT treatment, being -8.5 and -14.1 °C in LDHT and SDLT, respectively. The dry mass of roots, stems, and needles was lower in LF than in

  18. Diverging drought resistance of Scots pine provenances revealed by infrared thermography and mortality

    NASA Astrophysics Data System (ADS)

    Seidel, Hannes; Schunk, Christian; Matiu, Michael; Menzel, Annette

    2016-04-01

    Climate warming and more frequent and severe drought events will alter the adaptedness and fitness of tree species. Especially, Scots pine forests have been affected above average by die-off events during the last decades. Assisted migration of adapted provenances might help alleviating impacts by recent climate change and successfully regenerating forests. However, the identification of suitable provenances based on established ecophysiological methods is time consuming, sometimes invasive, and data on provenance-specific mortality are lacking. We studied the performance, stress and survival of potted Scots pine seedlings from 12 European provenances grown in a greenhouse experiment with multiple drought and warming treatments. In this paper, we will present results of drought stress impacts monitored with four different thermal indices derived from infrared thermography imaging as well as an ample mortality study. Percent soil water deficit (PSWD) was shown to be the main driver of drought stress response in all thermal indices. In spite of wet and dry reference surfaces, however, fluctuating environmental conditions, mainly in terms of air temperature and humidity, altered the measured stress response. In linear mixed-effects models, besides PSWD and meteorological covariates, the factors provenance and provenance - PSWD interactions were included. The explanatory power of the models (R2) ranged between 0.51 to 0.83 and thus, provenance-specific responses to strong and moderate drought and subsequent recovery were revealed. However, obvious differences in the response magnitude of provenances to drought were difficult to explicitly link to general features such Mediterranean - continental type or climate at the provenances' origin. We conclude that seedlings' drought resistance may be linked to summer precipitation and their experienced stress levels are a.o. dependent on their above ground dimensions under given water supply. In respect to mortality, previous

  19. Seasonal responses of photosynthetic electron transport in Scots pine (Pinus sylvestris L.) studied by thermoluminescence.

    PubMed

    Ivanov, A G; Sane, P V; Zeinalov, Y; Simidjiev, I; Huner, N P A; Oquist, G

    2002-07-01

    The potential of photosynthesis to recover from winter stress was studied by following the thermoluminescence (TL) and chlorophyll fluorescence changes of winter pine needles during the exposure to room temperature (20 degrees C) and an irradiance of 100 micromol m(-2) s(-1). TL measurements of photosystem II (PSII) revealed that the S(2)Q(B)(-) charge recombinations (the B-band) were shifted to lower temperatures in winter pine needles, while the S(2)Q(A)(-) recombinations (the Q-band) remained close to 0 degrees C. This was accompanied by a drastically reduced (65%) PSII photochemical efficiency measured as F(v)/ F(m,) and a 20-fold faster rate of the fluorescence transient from F(o) to F(m) as compared to summer pine. A strong positive correlation between the increase in the photochemical efficiency of PSII and the increase in the relative contribution of the B-band was found during the time course of the recovery process. The seasonal dynamics of TL in Scots pine needles studied under field conditions revealed that between November and April, the contribution of the Q- and B-bands to the overall TL emission was very low (less than 5%). During spring, the relative contribution of the Q- and B-bands, corresponding to charge recombination events between the acceptor and donor sides of PSII, rapidly increased, reaching maximal values in late July. A sharp decline of the B-band was observed in late summer, followed by a gradual decrease, reaching minimal values in November. Possible mechanisms of the seasonally induced changes in the redox properties of S(2)/S(3)Q(B)(-) recombinations are discussed. It is proposed that the lowered redox potential of Q(B) in winter needles increases the population of Q(A)(-), thus enhancing the probability for non-radiative P680(+)Q(A)(-) recombination. This is suggested to enhance the radiationless dissipation of excess light within the PSII reaction center during cold acclimation and during cold winter periods. PMID:12111228

  20. Bud endophytes of Scots pine produce adenine derivatives and other compounds that affect morphology and mitigate browning of callus cultures.

    PubMed

    Pirttilä, Anna Maria; Joensuu, Päivi; Pospiech, Helmut; Jalonen, Jorma; Hohtola, Anja

    2004-06-01

    Endophytes are found in meristematic bud tissues of Scots pine (Pinus sylvestris L.) especially prior to growth, which would suggest their involvement in growth of the bud. To test this hypothesis, production of phytohormones by two bacterial (Methylobacterium extorquens, Pseudomonas synxantha) and one fungal endophyte (Rhodotorula minuta) was studied by mass spectrometry. The most common gibberellins, auxins, or cytokinins were not detected in the fractions studied. Instead, M. extorquens and R. minuta produced adenine derivatives that may be used as precursors in cytokinin biosynthesis. A plant tissue culture medium was conditioned with the endophytes, and pine tissue cultures were started on the media. Tetracycline inhibited callus production, which was restored on the endophyte-conditioned media. In addition, conditioning mitigated browning of the Scots pine explants. However, a decrease in tissue size was observed on the endophyte-conditioned media. Addition of adenosine monophosphate in the plant culture medium restored callus production and increased growth of the tissues, but had no effect on browning. Therefore, production of adenine ribosides by endophytes may play some role in the morphological effect observed in the pine tissues. PMID:15153198

  1. Genetic variability and heritability of chlorophyll a fluorescence parameters in Scots pine (Pinus sylvestris L.).

    PubMed

    Čepl, Jaroslav; Holá, Dana; Stejskal, Jan; Korecký, Jiří; Kočová, Marie; Lhotáková, Zuzana; Tomášková, Ivana; Palovská, Markéta; Rothová, Olga; Whetten, Ross W; Kaňák, Jan; Albrechtová, Jana; Lstibůrek, Milan

    2016-07-01

    Current knowledge of the genetic mechanisms underlying the inheritance of photosynthetic activity in forest trees is generally limited, yet it is essential both for various practical forestry purposes and for better understanding of broader evolutionary mechanisms. In this study, we investigated genetic variation underlying selected chlorophyll a fluorescence (ChlF) parameters in structured populations of Scots pine (Pinus sylvestris L.) grown on two sites under non-stress conditions. These parameters were derived from the OJIP part of the ChlF kinetics curve and characterize individual parts of primary photosynthetic processes associated, for example, with the exciton trapping by light-harvesting antennae, energy utilization in photosystem II (PSII) reaction centers (RCs) and its transfer further down the photosynthetic electron-transport chain. An additive relationship matrix was estimated based on pedigree reconstruction, utilizing a set of highly polymorphic single sequence repeat markers. Variance decomposition was conducted using the animal genetic evaluation mixed-linear model. The majority of ChlF parameters in the analyzed pine populations showed significant additive genetic variation. Statistically significant heritability estimates were obtained for most ChlF indices, with the exception of DI0/RC, φD0 and φP0 (Fv/Fm) parameters. Estimated heritabilities varied around the value of 0.15 with the maximal value of 0.23 in the ET0/RC parameter, which indicates electron-transport flux from QA to QB per PSII RC. No significant correlation was found between these indices and selected growth traits. Moreover, no genotype × environment interaction (G × E) was detected, i.e., no differences in genotypes' performance between sites. The absence of significant G × E in our study is interesting, given the relatively low heritability found for the majority of parameters analyzed. Therefore, we infer that polygenic variability of these indices is

  2. Structure of Scots pine defensin 1 by spectroscopic methods and computational modeling.

    PubMed

    Ermakova, Elena A; Faizullin, Dzhigangir A; Idiyatullin, Bulat Z; Khairutdinov, Bulat I; Mukhamedova, Liya N; Tarasova, Nadezhda B; Toporkova, Yana Y; Osipova, Elena V; Kovaleva, Valentina; Gogolev, Yuri V; Zuev, Yuriy F; Nesmelova, Irina V

    2016-03-01

    Defensins are part of the innate immune system in plants with activity against a broad range of pathogens, including bacteria, fungi and viruses. Several defensins from conifers, including Scots pine defensin 1 (Pinus sylvestris defensin 1, (PsDef1)) have shown a strong antifungal activity, however structural and physico-chemical properties of the family, needed for establishing the structure-dynamics-function relationships, remain poorly characterized. We use several spectroscopic and computational methods to characterize the structure, dynamics, and oligomeric state of PsDef1. The three-dimensional structure was modeled by comparative modeling using several programs (Geno3D, SWISS-MODEL, I-TASSER, Phyre(2), and FUGUE) and verified by circular dichroism (CD) and infrared (FTIR) spectroscopy. Furthermore, FTIR data indicates that the structure of PsDef1 is highly resistant to high temperatures. NMR diffusion experiments show that defensin exists in solution in the equilibrium between monomers and dimers. Four types of dimers were constructed using the HADDOCK program and compared to the known dimer structures of other plant defensins. Gaussian network model was used to characterize the internal dynamics of PsDef1 in monomer and dimer states. PsDef1 is a typical representative of P. sylvestris defensins and hence the results of this study are applicable to other members of the family. PMID:26687241

  3. Environmental monitoring of trace elements in bark of Scots pine by thick-target PIXE

    NASA Astrophysics Data System (ADS)

    Harju, L.; Saarela, K.-E.; Rajander, J.; Lill, J.-O.; Lindroos, A.; Heselius, S.-J.

    2002-04-01

    Bark samples were taken from Scots pines ( Pinus sylvestris L.) from a polluted area near a metal plant and from a relatively non-polluted site. Thick-target particle-induced X-ray emission (PIXE) was used for the analyses after different types of prepreparation of the samples. The bark samples were analysed directly by radially scanning from inner to outer bark in order to study the variability of elemental concentrations in different layers. Some clear differences were found in the chemical composition of the inner and outer bark. The lowest detection limits for the analyses of heavy metal ions were obtained by combining dry ashing at 550 °C with the PIXE method. More than 100 times higher concentrations were found for the heavy metal ions Fe, Ni, Cu, Zn, Ga, As and Pb in the bark samples from a polluted area in comparison to samples from a non-polluted area. The work demonstrated that external-beam thick-target PIXE is a sensitive and reliable method for quantitative determination of heavy metals in tree bark samples.

  4. Simulated water balance of Scots pine stands in Sweden for different climate change scenarios

    NASA Astrophysics Data System (ADS)

    Gärdenäs, Annemieke I.; Jansson, Per-Erik

    1995-03-01

    The effects of climate change on the water balance of Scots pine were studied with a coupled water and heat flow model called 'SOIL'. Two forest soil types (a silty-sand and a sand) at five locations in Sweden were chosen to represent sites with different air temperature, growing season length and precipitation excess. The simulated water balance for the period 1961-1987 was compared with those simulated with two climate change scenario schemes: one is based on increased temperature and the other on both increased temperature and increased precipitation. Different assumptions regarding the effects of changes in leaf area index and minimum canopy resistance on transpiration were studied. Water stress increased substantially in the scenarios based on increased temperature only, which prevented transpiration from increasing. But with scenarios based on simultaneous changes in temperature and precipitation, water stress increased mainly during spring and transpiration increased by 50 mm and 100 mm in northern and southern Sweden, respectively, i.e. by 30-50%. When simultaneous changes in climate and stand characteristics were assumed, transpiration increased by 30-70% with the relative change being greatest for northern Sweden. Differences in water balance between the locations and soil types were less pronounced in the climate change scenarios than in the present climate scenario.

  5. Monitoring forest structure at landscape level: a case study of Scots pine forest in NE Turkey.

    PubMed

    Terzioğlu, Salih; Başkent, Emin Zeki; Kadioğullari, Ali Ihsan

    2009-05-01

    This study aims to investigate the change in spatial-temporal configuration of secondary forest succession and generate measurements for monitoring the changes in structural plant diversity in Yalnizçam Scots pine forest in NE Turkey from 1972 to 2005. The successional stages were mapped using the combination of Geographic Information System (GIS), Global Positioning System (GPS), aerial photos and high resolution satellite images (IKONOS). Forest structure and its relationship with structural plant diversity along with its changes over time were characterized using FRAGSTATS. In terms of spatial configuration of seral stages, the total number of fragments increased from 572 to 735, and mean size of patch (MPS) decreased from 154.97 ha to 120.60 ha over 33 years. The situation resulted in forestation serving appropriate conditions for plant diversity in the area. As an overall change in study area, there was a net increase of 1823.3 ha forest during the period with an average annual forestation rate of 55.25 ha year(-1) (0.4% per year). In conclusion, the study revealed that stand type maps of forest management plans in Turkey provide a great chance to monitor the changes in structural plant diversity over time. The study further contributes to the development of a framework for effective integration of biodiversity conservation into Multiple Use Forest Management (MUFM) plans using the successional stages as a critical mechanism. PMID:18553149

  6. Fine-scale diversity and distribution of ectomycorrhizal fungal mycelium in a Scots pine forest.

    PubMed

    Anderson, Ian C; Genney, David R; Alexander, Ian J

    2014-03-01

    Ectomycorrhizal (ECM) mycelium is a key component of the ectomycorrhizal symbiosis, yet we know little regarding the fine-scale diversity and distribution of mycelium in ECM fungal communities. We collected four 20 × 20 × 2-cm(3) (800-cm(3)) slices of Scots pine (Pinus sylvestris) forest soil and divided each into 100 2 × 2 × 2-cm(3) (8-cm(3)) cubes. The presence of mycelium of ECM fungi was determined using an internal transcribed spacer (ITS) database terminal restriction fragment length polymorphism (T-RFLP) approach. As expected, many more ECM fungi were detected as mycelium than as ectomycorrhizas in a cube or slice. More surprisingly, up to one-quarter of the 43 species previously detected as ectomycorrhizas over an area of 400 m(2) could be detected in a single 8-cm(3) cube, and up to three-quarters in a single 800-cm(3) slice. ECM mycelium frequency decreased markedly with depth and there were distinct 'hotspots' of mycelium in the moss/F1 layer. Our data demonstrate a high diversity of ECM mycelium in a small (8-cm(3) ) volume of substrate, and indicate that the spatial scale at which ECM species are distributed as mycelium may be very different from the spatial scale at which they are distributed as tips. PMID:24345261

  7. Plant size, not age, regulates growth and gas exchange in grafted Scots pine trees.

    PubMed

    Vanderklein, D; Martínez-Vilalta, J; Lee, S; Mencuccini, M

    2007-01-01

    We studied the effect of scion donor-tree age on the physiology and growth of 6- to 7-year-old grafted Scots pine (Pinus sylvestris L.) trees (4 and 5 years after grafting). Physiological measurements included photosynthethetic rate, stomatal conductance, transpiration, whole plant hydraulic conductance, needle nitrogen concentration and carbon isotope composition. Growth measurements included total and component biomasses, relative growth rates and growth efficiency. Scion donor trees ranged in age from 36 to 269 years at the time of grafting. Hydraulic conductance was measured gravimetrically, applying the Ohm's law analogy, and directly, with a high-pressure flow meter. We found no effect of scion donor-tree age on any of the variables measured. There was, however, great variation within scion donor-tree age groups, which was related to the size of the grafted trees. Differences in size may have been caused by variable initial grafting success, but there was no indication that grafting success and age were related. At the stem level, hydraulic conductance scaled with total leaf area so that total conductance per unit leaf area did not vary with crown size. However, leaf specific hydraulic conductance (gravimetric), transpiration, photosynthesis and stomatal conductance declined with increasing total tree leaf area and needle width. We hypothesize that needle width is inversely related to mesophyll conductance. We conclude that canopy and needle size and not scion donor-tree age determined gas exchange in our grafted trees. PMID:17169908

  8. Interspecific differences in foliar 1 PAHs load between Scots pine, birch, and wild rosemary from three polish peat bogs.

    PubMed

    Mętrak, Monika; Aneta, Ekonomiuk; Wiłkomirski, Bogusław; Staszewski, Tomasz; Suska-Malawska, Małgorzata

    2016-08-01

    Pine needles are one of the most commonly used bioindicators of polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the main objective of the current research was the assessment of PAHs accumulation potential of Scots pine (Pinus sylvestris L.) needles in comparison to wild rosemary (Rhododendron tomentosum Harmaja) and birch (Betula spp.) leaves. Our study was carried out on three peat bogs subjected to different degree of anthropopression, which gave us also the opportunity to identify local emission sources. Pine needles had the lowest accumulation potential from all the studied species. The highest accumulation potential, and hence carcinogenic potential, was observed for wild rosemary leaves. As far as emission sources are concerned, the most pronounced influence on atmospheric PAHs loads had traditional charcoal production, resulting in great influx of heavy PAHs. Observed seasonal changes in PAHs concentrations followed the pattern of winter increase, caused mainly by heating season, and summer decrease, caused mainly by volatilization of light PAHs. PMID:27393196

  9. Response of needle sulphur and nitrogen concentrations of Scots pine versus Norway spruce to SO2 and NO2.

    PubMed

    Manninen, S; Huttunen, S

    2000-03-01

    The results of two field studies and an open-top chamber fumigation experiment showed that the response of mature Scots pine to SO(2) and NO(2) differed from that of mature Norway spruce. Moreover, the response of pine seedlings to SO(2) and NO(2) differed from that of mature trees. The greater increase in the needle total S concentrations of pine suggested more abundant stomatal uptake of SO(2) compared to spruce. Both pine seedlings and mature trees also seemed to absorb more N from atmospheric deposition. Mature pine was able to assimilate SO(4)(2-) derived from SO(2) into organic S more effectively than mature spruce at the high S and N deposition sites, whereas both pine and spruce seedlings accumulated SO(4)-S under NO(2)+SO(2) exposure. Spruce, in turn, accumulated SO(4)-S even when well supplied with N. Net assimilation of SO(4)(2-) in conifer seedlings was enhanced markedly by elevated temperature. To protect the northern coniferous forests against the harmful effects of S and N deposition, it is recommended that the critical level for SO(2) as a growing season mean be set at 5-10 microg m(-3) and NO(2) at 10-15 microg m(-3), depending on the 'effective temperature sum' and/or whether SO(2) and NO(2) occur alone or in combination. PMID:15092988

  10. [Development of New Mitochondrial DNA Markers in Scots Pine (Pinus sylvestris L.) for Population Genetic and Phylogeographic Studies].

    PubMed

    Semerikov, V L; Putintseva, Yu A; Oreshkova, N V; Semerikova, S A; Krutovsky, K V

    2015-12-01

    Fragments of genomic DNA of Scots pine (Pinus sylvestris L.) homologous to the mitochondrial DNA (mtDNA) contigs of Norway spruce (Picea abies (L.) Karst.) and loblolly pine (Pinus taeda L.) were resequenced in a sample of the Scots pine trees of European, Siberian, Mongolian and Caucasian origin in order to develop mtDNA markers. Flanking non-coding regions of some mitochondrial genes were also investigated and resequenced. Five single nucleotide polymorphisms (SNPs) and a single minisatellite locus were identified. Caucasian samples differed from the rest by three SNPs. Two SNPs have been linked to an early described marker in.the first intron of the nad7 gene, and all together revealed three haplotypes in European populations. No variable SNPs were found in the Siberian and Mongolian populations. The minisatellite locus contained 41 alleles across European, Siberian and Mongolian populations, but, this locus demonstrated a weak population differentiation (F(ST) = 0.058), probably due to its high mutation rate. PMID:27055298

  11. Detection of multiple stresses in Scots pine growing at post-mining sites using visible to near-infrared spectroscopy.

    PubMed

    Zuzana, Lhotáková; Lukáš, Brodský; Lucie, Kupková; Veronika, Kopačková; Markéta, Potůčková; Jan, Mišurec; Aleš, Klement; Monika, Kovářová; Jana, Albrechtová

    2013-10-01

    Heavy metal contamination, low pH and high substrate heterogeneity are multiple stress factors that often occur at the post-mining sites and make difficult the biological reclamation. Efficient tools for detection of the status of reclaimed vegetation at post-mining sites are needed. We tested the potential of visible to near-infrared (VNIR) spectroscopy to detect multiple stresses in Scots pine (Pinus sylvestris L.) at acidic substrates rich in As. The needle chemical traits (chlorophyll a + b - Cab; carotenoids - Car; Car/Cab; relative water content - RWC; soluble phenolics; lignin contents) were tested for sensitivity to different soil conditions of post-mining sites. For Scots pine growing on degraded substrates, at least three non-specific stress indicators (RWC, photosynthetic pigments and phenolics) are required to achieve good site separability corresponding to the stress load. We constructed and validated empirical models of selected needle chemical traits using VNIR spectroscopy: calibration of Cab (R(2) = 0.97, RMSE = 0.17 mg g(-1)), RWC (R(2) = 0.88, RMSE = 1.41 mg g(-1)), Car (R(2) = 0.66, RMSE = 0.08 mg g(-1)), phenolics (R(2) = 0.64, RMSE = 23.01 mg g(-1)) and lignin (R(2) = 0.45, RMSE = 3.32 mg g(-1)). The reflectance data yielded comparable site separability with the separability calculated from the laboratory data. The presented approach has potential for large-scale monitoring of Scots pine status, thus, assessment of reclamation quality in post-mining regions using air-born or satellite hyperspectral data. PMID:24108147

  12. Excitation energy partitioning and quenching during cold acclimation in Scots pine.

    PubMed

    Sveshnikov, Dmitry; Ensminger, Ingo; Ivanov, Alexander G; Campbell, Douglas; Lloyd, Jon; Funk, Christiane; Hüner, Norman P A; Oquist, Gunnar

    2006-03-01

    We studied the influence of two irradiances on cold acclimation and recovery of photosynthesis in Scots pine (Pinus sylvestris L.) seedlings to assess mechanisms for quenching the excess energy captured by the photosynthetic apparatus. A shift in temperature from 20 to 5 degrees C caused a greater decrease in photosynthetic activity, measured by chlorophyll fluorescence and oxygen evolution, in plants exposed to moderate light (350 micromol m(-2) s(-1)) than in shaded plants (50 micromol m(-2) s(-1)). In response to the temperature shift, maximal photochemical efficiency of photosystem II (PSII), measured as the ratio of variable to maximal chlorophyll fluorescence (Fv/Fm) of dark-adapted samples, decreased to 70% in exposed seedlings, whereas shaded seedlings maintained Fv/Fm close to initial values. After a further temperature decrease to -5 degrees C, only 8% of initial Fv/Fm remained in exposed plants, whereas shaded plants retained 40% of initial Fv/Fm. Seven days after transfer from -5 to 20 degrees C, recovery of photochemical efficiency was more complete in the shaded plants than in the exposed plants (87 and 65% of the initial Fv/Fm value, respectively). In response to cold stress, the estimated functional absorption cross section per remaining PSII reaction center increased at both irradiances, but the increase was more pronounced in exposed seedlings. Estimates of energy partitioning in the needles showed a much higher dissipative component in the exposed seedlings at low temperatures, pointing to stronger development of non-photochemical quenching at moderate irradiances. The de-epoxidation state of the xanthophyll cycle pigments increased in exposed seedlings at 5 degrees C, contributing to the quenching capacity, whereas significant de-epoxidation in the shaded plants was observed only when temperatures decreased to -5 degrees C. Thermoluminescence (TL) measurements of PSII revealed that charge recombinations between the second oxidation state of Mn

  13. How surface fire in Siberian Scots pine forests affects soil organic carbon in the forest floor: Stocks, molecular structure, and conversion to black carbon (charcoal)

    NASA Astrophysics Data System (ADS)

    Czimczik, Claudia I.; Preston, Caroline M.; Schmidt, Michael W. I.; Schulze, Ernst-Detlef

    2003-03-01

    In boreal forests, fire is a frequent disturbance and converts soil organic carbon (OC) to more degradation-resistant aromatic carbon, i.e., black carbon (BC) which might act as a long-term atmospheric-carbon sink. Little is known on the effects of fires on boreal soil OC stocks and molecular composition. We studied how a surface fire affected the composition of the forest floor of Siberian Scots pine forests by comparing the bulk elemental composition, molecular structure (13C-MAS NMR), and the aromatic carbon fraction (BC and potentially interfering constituents like tannins) of unburned and burned forest floor. Fire reduced the mass of the forest floor by 60%, stocks of inorganic elements (Si, Al, Fe, K, Ca, Na, Mg, Mn) by 30-50%, and of OC, nitrogen, and sulfur by 40-50%. In contrast to typical findings from temperate forests, unburned OC consisted mainly of (di-)O-alkyl (polysaccharides) and few aromatic structures, probably due to dominant input of lichen biomass. Fire converted OC into alkyl and aromatic structures, the latter consisting of heterocyclic macromolecules and small clusters of condensed carbon. The small cluster size explained the small BC concentrations determined using a degradative molecular marker method. Fire increased BC stocks (16 g kg-1 OC) by 40% which translates into a net-conversion rate of 0.7% (0.35% of net primary production) unburned OC to BC. Here, however, BC was not a major fraction of soil OC pool in unburned or burned forest floor, either due to rapid in situ degradation or relocation.

  14. Maternal heterozygosity and progeny fitness association in an inbred Scots pine population.

    PubMed

    Abrahamsson, S; Ahlinder, J; Waldmann, P; García-Gil, M R

    2013-03-01

    Associations between heterozygosity and fitness traits have typically been investigated in populations characterized by low levels of inbreeding. We investigated the associations between standardized multilocus heterozygosity (stMLH) in mother trees (obtained from12 nuclear microsatellite markers) and five fitness traits measured in progenies from an inbred Scots pine population. The traits studied were proportion of sound seed, mean seed weight, germination rate, mean family height of one-year old seedlings under greenhouse conditions (GH) and mean family height of three-year old seedlings under field conditions (FH). The relatively high average inbreeding coefficient (F) in the population under study corresponds to a mixture of trees with different levels of co-ancestry, potentially resulting from a recent bottleneck. We used both frequentist and Bayesian methods of polynomial regression to investigate the presence of linear and non-linear relations between stMLH and each of the fitness traits. No significant associations were found for any of the traits except for GH, which displayed negative linear effect with stMLH. Negative HFC for GH could potentially be explained by the effect of heterosis caused by mating of two inbred mother trees (Lippman and Zamir 2006), or outbreeding depression at the most heterozygote trees and its negative impact on the fitness of the progeny, while their simultaneous action is also possible (Lynch. 1991). However,since this effect wasn't detected for FH, we cannot either rule out that the greenhouse conditions introduce artificial effects that disappear under more realistic field conditions. PMID:23400838

  15. Effects of zinc on Scots pine (Pinus sylvestris L.) seedlings grown in hydroculture.

    PubMed

    Ivanov, Yury V; Kartashov, Alexander V; Ivanova, Alexandra I; Savochkin, Yury V; Kuznetsov, Vladimir V

    2016-05-01

    The 6-week-old seedlings of Scots pine (Pinus sylvestris L.) showed high sensitivity to chronic exposure to zinc in hydroculture, which manifested in a significant inhibition of growth. Changes in the architecture of the root system and the suppression of its growth were shown to be the most striking effects of the toxic effect of zinc. Based on the data relating to the accumulation of zinc predominantly in the root system (by up to 35 times at 300 μM ZnSO4) and to the reduction in its translocation into the aerial organs, we concluded that P. sylvestris is related to a group of plants that exclude zinc. The seedlings developed a manganese deficiency (revealed by a reduction in Mn content in the roots and needles of up to 3.5 times at 300 μM ZnSO4) but not an iron deficiency (revealed by an increase in iron content of up to 23.7% in the roots and up to 42.3% in the needles at average). The absence of signs of oxidative stress under the effect of the zinc was detected as evidenced by the reduction in the content of malondialdehyde and 4-hydroxyalkenals in the seedling organs. The leading role of low molecular weight antioxidants in the prevention of oxidative stress in the seedling organs was suggested. Under the influence of zinc, a significant increase in the Trolox Equivalent Antioxidant Capacity of ethanol extracts of the seedling organs was found, which was caused by an increase in the total content of (+)-catechin and proanthocyanidins. PMID:26897114

  16. Function and Dynamics of Auxin and Carbohydrates during Earlywood/Latewood Transition in Scots Pine1

    PubMed Central

    Uggla, Claes; Magel, Elisabeth; Moritz, Thomas; Sundberg, Björn

    2001-01-01

    In temperate regions the annual pattern of wood development is characterized by the formation of radially narrow and thick walled latewood cells. This takes place at the later part of the growing season when cambial cell division declines. To gain new insight into the regulation of this process, micro-analytical techniques were used to visualize the distribution of indole-3-acetic acid (IAA), soluble carbohydrates, and activities of sucrose (Suc)-metabolizing enzymes across the cambial region tissues in Scots pine (Pinus sylvestris). The total amount of IAA in the cambial region did not change with latewood initiation. But its radial distribution pattern was altered, resulting in an increased concentration in the cambial meristem and its recent derivatives. Thus, initiation of latewood formation and cessation of cambial cell division is not a consequence of decreased IAA concentrations in dividing and expanding cells. Rather, IAA most likely has a role in defining the altered developmental pattern associated with latewood formation. Carbohydrates and enzyme activities showed distinctive radial distribution patterns. Suc peaked in the phloem and decreased sharply to low levels across the cambial zone, whereas fructose and glucose reached their highest levels in the maturing tracheids. Suc synthase was the dominating Suc cleaving enzyme with a peak in the secondary wall-forming tracheids and in the phloem. Soluble acid invertase peaked in dividing and expanding cells. Suc-phosphate synthase had its highest activities in the phloem. Activities of cell wall bound invertase were low. The absence of major seasonal variations indicates that carbohydrate availability is not a trigger for latewood initiation. However, steep concentration gradients of the sugars suggest a role for sugar signaling in vascular development. PMID:11299382

  17. Trait-specific responses of Scots pine to irrigation on a short vs long time scale.

    PubMed

    Feichtinger, Linda M; Eilmann, Britta; Buchmann, Nina; Rigling, Andreas

    2015-02-01

    In xeric environments, an increase in drought is related to reduced forest productivity and to enhanced mortality. However, predictions of future forest development remain difficult as the mechanisms underlying the responses of mature trees to long-term variations in water availability are not well understood. Here, we aimed to compare the adjustments in radial growth and morphological needle and shoot traits of mature Scots pine (Pinus sylvestris L.) growing along open water channels with those of control trees growing under naturally dry conditions at three sites in Valais, an inner-Alpine dry valley of Switzerland. The trees growing along two channels had been irrigated since germination (>70 years), whereas those along another previously drained channel had been irrigated only from 2010 to 2012, when the channel was re-established, and could thus be used to quantify the short-term effects of re-irrigation. Linear mixed models revealed that needle and shoot lengths as well as early- and late-wood basal area increments (BAIs) were most responsive to short-term and long-term irrigation. However, the magnitude of the response to the short-term irrigation exceeded that of the long-term irrigation. An extreme drought during the first half of 2011 led to an immediate decrease in the needle length, needle width, and early- and late-wood BAIs of the control trees, whereas the shoot length and needle numbers of control trees reacted with a 1-year delay to the extreme drought, as the shoots were responding to water availability of previous year's summer. Such negative responses to dry climatic conditions were even found in irrigated trees at one of our sites, which might be linked to tree growth becoming more sensitive to drought with increasing tree height and leaf area. In order to improve predictions of future forest development, long-term studies are necessary that consider lagged responses and adjustment processes of trees to changes in water availability. PMID

  18. The true distribution and accumulation of radiocaesium in stem of Scots pine (Pinus sylvestris L.).

    PubMed

    Thiry, Yves; Goor, Francois; Riesen, Thomas

    2002-01-01

    The radial and vertical distributions of radiocaesium, potassium and calcium were determined in two Scots pine stands (17 and 58 yr old) similarly affected by the Chernobyl fallout. For both age classes, concentrations are always the lowest in the stemwood, highest in the inner bark and intermediary levels were observed for the outer bark. Due to the cumulative character of its biomass. however. stemwood is a long-term major reservoir of 137Cs. With tree development, changes in the 137Cs radial distribution are well described by variations in the sap ascent pattern and reveal an important transfer between tree rings. It is shown that. both the biomass evolution and knowledge of the evolution of the 137Cs radial gradient are important to predicting 137Cs accumulation in wood with time. According to the common transfer factor (TF) approach, one would expect a decrease in radiocaesium accumulation with time (from 0.0047 +/- 0.0013 to 0.0035 +/- 0.0008 m2kg(-1) for the 17 and 58 yr old trees, respectively). With the wood immobilisation potential (WIP) approach, it was, however, clearly shown that additional annual uptake was highest for the older stand (3.12 +/- 0.23 Bq cm(-3) yr(-1) for the 58-year-old stand compared to 1.99 +/- 0.30 Bq cm(-3) yr(-1) for the younger stand). Following the WIP approach, it was moreover possible to distinguish between the 137Cs incorporated via the root uptake process and a possible lasting effect of interception. It is shown that, whereas for the younger stand (5 yr old at the time of the accident) root uptake contributed exclusively to the wood contamination, the former process explained only 48% of the measured total 137Cs content in the wood of the older tree. PMID:11814168

  19. Functional Multi-Locus QTL Mapping of Temporal Trends in Scots Pine Wood Traits

    PubMed Central

    Li, Zitong; Hallingbäck, Henrik R.; Abrahamsson, Sara; Fries, Anders; Gull, Bengt Andersson; Sillanpää, Mikko J.; García-Gil, M. Rosario

    2014-01-01

    Quantitative trait loci (QTL) mapping of wood properties in conifer species has focused on single time point measurements or on trait means based on heterogeneous wood samples (e.g., increment cores), thus ignoring systematic within-tree trends. In this study, functional QTL mapping was performed for a set of important wood properties in increment cores from a 17-yr-old Scots pine (Pinus sylvestris L.) full-sib family with the aim of detecting wood trait QTL for general intercepts (means) and for linear slopes by increasing cambial age. Two multi-locus functional QTL analysis approaches were proposed and their performances were compared on trait datasets comprising 2 to 9 time points, 91 to 455 individual tree measurements and genotype datasets of amplified length polymorphisms (AFLP), and single nucleotide polymorphism (SNP) markers. The first method was a multilevel LASSO analysis whereby trend parameter estimation and QTL mapping were conducted consecutively; the second method was our Bayesian linear mixed model whereby trends and underlying genetic effects were estimated simultaneously. We also compared several different hypothesis testing methods under either the LASSO or the Bayesian framework to perform QTL inference. In total, five and four significant QTL were observed for the intercepts and slopes, respectively, across wood traits such as earlywood percentage, wood density, radial fiberwidth, and spiral grain angle. Four of these QTL were represented by candidate gene SNPs, thus providing promising targets for future research in QTL mapping and molecular function. Bayesian and LASSO methods both detected similar sets of QTL given datasets that comprised large numbers of individuals. PMID:25305041

  20. Water flux estimates from a Belgian Scots pine stand: a comparison of different approaches

    NASA Astrophysics Data System (ADS)

    Meiresonne, L.; Sampson, D. A.; Kowalski, A. S.; Janssens, I. A.; Nadezhdina, N.; Cermák, J.; Van Slycken, J.; Ceulemans, R.

    2003-01-01

    Four distinct approaches, that vary markedly in the spatial and temporal resolution of their measurement and process-level outputs, are used to investigate the daily and seasonal water vapour exchange in a 70-year-old Belgian Scots pine forest. Transpiration, canopy interception, soil evaporation and evapotranspiration are simulated, using a stand-level process model (SECRETS) and a soil water balance model (WAVE). Simulated transpiration was compared with up-scaled sap flow measurements and simulated evapotranspiration to eddy covariance measurements. Reasonable agreement in the temporal trends and in the annual water balance between the two models was observed, however daily and weekly predictions often diverged. Most notably, WAVE estimated very low, to no transpiration during late autumn, winter and early spring when incident radiation fell below ˜50 W m -2 while SECRETS simulated low (0.1-0.4 mm day -1) fluxes during the same period. Both models exhibited similar daily trends in simulated transpiration when compared with sap flow estimates, although simulations from SECRETS were more closely aligned. In contrast, WAVE over-estimated transpiration during periods of no rainfall and under-estimated transpiration during rainfall. Yearly, total evapotranspiration simulated by the models were similar, i.e. 658 mm (1997) and 632 mm (1998) for WAVE and 567 mm (1997) and 619 mm (1998) for SECRETS. Maximum weekly-average evapotranspiration for WAVE exceeded 5 mm day -1, while SECRETS never exceeded 4 mm day -1. Both models, in general, simulated higher evapotranspiration than that measured with the eddy covariance technique. An impact of the soil water content in the direct relationship between the models and the eddy covariance measurements was found. The results suggest that: (1) different model formulations can reproduce similar results depending on the scale at which outputs are resolved, (2) SECRETS estimates of transpiration were well correlated with the

  1. Effects of elevated CO 2 and temperature on monoterpene emission of Scots pine ( Pinus sylvestris L.)

    NASA Astrophysics Data System (ADS)

    Räisänen, Tommi; Ryyppö, Aija; Kellomäki, Seppo

    2008-06-01

    The aim of this study was to evaluate the long-term (5 years) effects of elevated CO2 concentration (doubling of ambient CO2 concentration) and temperature (2-6 °C elevation) on the monoterpene emission of Scots pine (Pinus sylvestris L.) saplings (ca. 20 years old) grown in closed-top environmental chambers. The chamber treatments included: (1) ambient temperature and CO2, (2) ambient temperature and elevated CO2, (3) elevated temperature and ambient CO2, and (4) elevated temperature and elevated CO2. The variability of emissions during and after tree shoot growth was studied, and additionally the total cumulative emission of monoterpenes through a growing period (May-September) was estimated. When compared to the controls, the combination of elevated CO2 and temperature significantly increased normalized monoterpene emission rate for the whole growing period (+23%), whereas elevated CO2 had no significant effect (-4%), and elevated temperature even decreased (-41%) the emission rate. The increasing effect of the combination of elevated CO2 and temperature was strongest during shoot growth (+54%). After shoot growth, no significant differences in emission rate were found among the treatments. Emission modeling showed that the total amount of monoterpenes emitted from May to September was 2.38 mg gdw-1 in ambient conditions. The total emission in elevated CO2 was 5% greater and in elevated temperature 9% lesser than in ambient conditions. The combination of elevated CO2 and temperature increased the amount of emitted monoterpenes over the growing period by 126% compared to the total emission in ambient conditions.

  2. Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest

    NASA Astrophysics Data System (ADS)

    Vermeulen, M. H.; Kruijt, B. J.; Hickler, T.; Kabat, P.

    2015-07-01

    The vegetation-atmosphere carbon and water exchange at one particular site can strongly vary from year to year, and understanding this interannual variability in carbon and water exchange (IAVcw) is a critical factor in projecting future ecosystem changes. However, the mechanisms driving this IAVcw are not well understood. We used data on carbon and water fluxes from a multi-year eddy covariance study (1997-2009) in a Dutch Scots pine forest and forced a process-based ecosystem model (Lund-Potsdam-Jena General Ecosystem Simulator; LPJ-GUESS) with local data to, firstly, test whether the model can explain IAVcw and seasonal carbon and water exchange from direct environmental factors only. Initial model runs showed low correlations with estimated annual gross primary productivity (GPP) and annual actual evapotranspiration (AET), while monthly and daily fluxes showed high correlations. The model underestimated GPP and AET during winter and drought events. Secondly, we adapted the temperature inhibition function of photosynthesis to account for the observation that at this particular site, trees continue to assimilate at very low atmospheric temperatures (up to daily averages of -10 °C), resulting in a net carbon sink in winter. While we were able to improve daily and monthly simulations during winter by lowering the modelled minimum temperature threshold for photosynthesis, this did not increase explained IAVcw at the site. Thirdly, we implemented three alternative hypotheses concerning water uptake by plants in order to test which one best corresponds with the data. In particular, we analyse the effects during the 2003 heatwave. These simulations revealed a strong sensitivity of the modelled fluxes during dry and warm conditions, but no single formulation was consistently superior in reproducing the data for all timescales and the overall model-data match for IAVcw could not be improved. Most probably access to deep soil water leads to higher AET and GPP simulated

  3. Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest

    NASA Astrophysics Data System (ADS)

    Vermeulen, M. H.; Kruijt, B. J.; Hickler, T.; Kabat, P.

    2015-02-01

    Vegetation - atmosphere carbon and water exchange at one particular site can strongly vary from year to year, and understanding this interannual variability in carbon and water exchange (IAVcw) is a critical factor in projecting future ecosystem changes. However, the mechanisms driving this IAVcw are not well understood. We used data on carbon and water fluxes from a multi-year Eddy Covariance study (1997-2009) in a Dutch Scots pine forest and forced a process-based ecosystem model (LPJ-GUESS) with local data to, firstly, test whether the model can explain IAVcw and seasonal carbon and water exchange from direct environmental factors only. Initial model runs showed low correlations with estimated annual gross primary productivity (GPP) and annual actual evapotranspiration (AET), while monthly and daily fluxes showed high correlations. The model underestimated GPP and AET during winter and drought events. Secondly, we adapted the temperature inhibition function of photosynthesis to account for the observation that at this particular site, trees continue to assimilate at very low atmospheric temperatures (up to daily averages of -10 °C), resulting in a net carbon sink in winter. While we were able to improve daily and monthly simulations during winter by lowering the modelled minimum temperature threshold for photosynthesis, this did not increase explained IAVcw at the site. Thirdly, we implemented three alternative hypotheses concerning water uptake by plants in order to test which one best corresponds with the data. In particular, we analyse the effects during the 2003 heatwave. These simulations revealed a strong sensitivity of the modelled fluxes during dry and warm conditions, but no single formulation was consistently superior in reproducing the data for all time scales and the overall model-data match for IAVcw could not be improved. Most probably access to deep soil water leads to higher AET and GPP simulated during the heat wave of 2003. We conclude that

  4. Fire Impact on Carbon Emissions on Logged and Unlogged Scots pine Forest Sites in Siberia

    NASA Astrophysics Data System (ADS)

    Ivanova, G.; Kukavskaya, E.; Buryak, L.; Kalenskaya, O.; Bogorodskaya, A.; Conard, S. G.

    2012-12-01

    Fires cover millions ha of boreal forests of Russia annually, mostly in Siberia. Wildfire and forest harvesting are the major disturbances in Siberia's boreal zone. Logged areas appear to be highly susceptible to fire due to a combination of high fuel loads and accessibility for human-caused ignition. Fire spreading from logging sites to surrounding forest is a common situation in this region. Changing patterns of timber harvesting increase landscape complexity and can be expected to increase the emissions and ecosystem damage from wildfires, inhibit recovery of natural ecosystems, and exacerbate impacts of wildfire on changing climate and on air quality. Fire effects on pine stands and biomass of surface vegetation were estimated on logged and unlogged sites in the Central Siberia region as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). Fires occurring on logged areas were typically of higher severity than those in unlogged forests, but the specific effects of fire and logging varied widely among forest types and as a result of weather patterns during and prior to the fire. Consumption of surface and ground fuels in spring fires was 25% to 50% of that in summer fires. Estimated carbon emissions due to fire were 2-5 times higher on logged areas compared to undisturbed sites. Post-fire soil respiration decreases found for both site types partially offset carbon losses. Carbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions in Siberia.

  5. [Dose dependence of the frequency of morphological changes in Scots pine (Pinus sylvestris L.) in Chernobyl exclusion zone].

    PubMed

    Ioshchenko, V I; Bondar', Iu O

    2009-01-01

    Patterns and main parameters of the dynamics of radioactive contamination of organs of Scots pine in the plantations of Chernobyl zone are presented. On the basis of this data and within the frameworks of the microdosimetric approach, the dosimetric model for the apical meristem of the pine trees was created. The dose rates were calculated for the trees of the experimental array growing at three sites in the exclusion zone and one outside, which differed by three orders of magnitude of the trees' radioactive contamination levels. Comparable high, up to several Gy/y, levels of the dose rate of chronic irradiation were shown for the plantation at the Red Forest site. Such an expressed radiation factor results in a high frequency of the morphological changes at this site. The dose rate-effect dependence was formulated for this type of the radiobiological effects. PMID:19368333

  6. Seasonal and spatial variability of rainfall redistribution under Scots pine and Downy oak forests in Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Garcia-Estringana, Pablo; Latron, Jérôme; Molina, Antonio J.; Llorens, Pilar

    2013-04-01

    The large degree of temporal and spatial variability of throughfall input patterns may lead to significant changes in the volume of water that reach the soil in each location, and beyond in the hydrological response of forested hillslopes. To explore the role of vegetation in the temporal and spatial redistribution of rainfall in Mediterranean climatic conditions two contrasted stands were monitored. One is a Downy oak forest (Quercus pubescens) and the other is a Scots pine forest (Pinus sylvestris), both are located in the Vallcebre research catchments (NE Spain, 42° 12'N, 1° 49'E). These plots are representative of Mediterranean mountain areas with spontaneous afforestation by Scots pine as a consequence of the abandonment of agricultural terraces, formerly covered by Downy oaks. The monitoring design of each plot consists of a set of 20 automatic rain recorders and 40 automatic soil moisture probes located below the canopy. 100 hemispheric photographs of the canopy were used to place the instruments at representative locations (in terms of canopy cover) within the plot. Bulk rainfall, stemflow and meteorological conditions above the forest cover are also automatically recorded. Canopy cover as well as biometric characteristics of the plots are also regularly measured. This work presents the first results describing the variability of throughfall beneath each forest stand and compares the persistence of temporal patterns among stands, and for the oaks stand among the leafed and the leafless period. Furthermore, canopy structure, rainfall characteristics and meteorological conditions of rainfall events are evaluated as main drivers of throughfall redistribution.

  7. Variation and inheritance pattern in cone and seed characteristics of Scots pine (Pinus sylvestris L.) for evaluation of genetic diversity.

    PubMed

    Sevik, Hakan; Topaçoğlu, Osman

    2015-09-01

    Scots pine (Pinus sylvestris L.) is one of the most common and important forest tree species in Turkey due to usefulness of its wood to many commercial uses. This species is classified as one of the economically important tree species for Turkish Forestry in the "National Tree Breeding and Seed Production Program". The objective of the present study was to investigate variation and inheritance pattern in cone and seed characteristics of Scots pine and to evaluate variation in cone and seed characters within and among clones and grafts. The results showed that maximum CV among the clones was found for SWe (21.95), FS (16.99) and CWe (16.88). According to the results of SAS, variation between the clones is averaged at 19.2% and variation within the clones is averaged at 24.4 %. Variation between the clones ranged from 3.6% (SW) to 34.5% (TC) and variation within the clones ranged from 12.3% (SW) to 38.1% (WL). For CW, AL, AW, WW and TC, genetic variation among clones was higher than within clones. When the results of study like compared with results obtained from natural populations, it was seen that genetic variability in seed orchard which was subjected to study was quite low. This case may have dangerous results for the future of forests. PMID:26521555

  8. Dynamic relationship between the VOC emissions from a Scots pine stem and the tree water relations

    NASA Astrophysics Data System (ADS)

    Vanhatalo, Anni; Chan, Tommy; Aalto, Juho; Kolari, Pasi; Rissanen, Kaisa; Hakola, Hannele; Hölttä, Teemu; Bäck, Jaana

    2013-04-01

    The stems of coniferous trees contain huge storages of oleoresin. The composition of oleoresin depends on e.g. tree species, age, provenance, health status, and environmental conditions. Oleoresin is under pressure in the extensive network of resin ducts in wood and needles. It flows out from a mechanically damaged site to protect the tree by sealing the wounded site. Once in contact with air, volatile parts of oleoresin evaporate, and the residual compounds harden to make a solid protective seal over damaged tissues. The hardening time of the resin depends on evaporation rate of the volatiles which in turn depends on temperature. The storage is also toxic to herbivores and attracts predators that restrict the herbivore damage. Despite abundant knowledge on emissions of volatile isoprenoids from foliage, very little is known about their emissions from woody plant parts. We set up an experiment to measure emissions of isoprene and monoterpenes as well as two oxygenated VOCs, methanol and acetone, from a Scots pine (Pinus sylvestris) stem and branches. The measurements were started in early April and continued until mid-June, 2012. Simultaneously, we measured the dynamics of whole stem and xylem diameter changes, stem sap flow rate and foliage transpiration rate. These measurements were used to estimate A) pressure changes inside the living stem tissue and the water conducting xylem, B) the refilling of stem water stores after winter dehydration (the ratio of sap flow at the stem base to water loss by foliage), and C) the increase in tree water transport capacity (the ratio of maximum daily sap flow rate to the diurnal variation in xylem pressure) during spring due to winter embolism refilling and/or the temperature dependent root water uptake capacity. The results show that already very early in spring, significant VOC emissions from pine stem can be detected, and that they exhibit a diurnal cycle similar to that of ambient temperature. During the highest emission

  9. Seasonal dynamics of mobile carbohydrates and stem growth in Scots pine (Pinus sylvestris) exposed to drought

    NASA Astrophysics Data System (ADS)

    Oberhuber, Walter; Kofler, Werner; Schuster, Roman; Swidrak, Irene; Gruber, Andreas

    2014-05-01

    Tree growth requires a continuous supply of carbon as structural material and as a source for metabolic energy. To detect whether intra-annual stem growth is related to changes in carbon allocation, we monitored seasonal dynamics of shoot and radial growth and concentrations of mobile carbohydrates (NSC) in above- and belowground organs of Scots pine (Pinus sylvestris L.). The study area is situated within an inner Alpine dry environment (750 m asl, Tyrol, Austria), which is characterized by recurring drought periods at the start of the growing season in spring and limited water holding capacity of nutrient deficient, shallow stony soils. Shoot elongation was monitored on lateral branches in the canopy and stem radius changes were continuously followed by electronic band dendrometers. Daily radial stem growth and tree water deficit (ΔW) were extracted from dendrometer records. ΔW is regarded a reliable measure of drought stress in trees and develops when transpirational water loss from leaves exceeds water uptake by the root system. Daily radial stem growth and ΔW were related to environmental variables and determination of NSC was performed using specific enzymatic assays. Results revealed quite early culmination of aboveground growth rates in late April (shoot growth) and late May (radial growth), and increasing accumulation of NSC in coarse roots in June. NSC content in roots peaked at the end of July and thereafter decreased again, indicating a shift in carbon allocation after an early cessation of aboveground stem growth. ΔW was found to peak in late summer, when high temperatures prevailed. That maximum growth rates of aboveground organs peaked quite before precipitation increased during summer is related to the finding that ΔW and radial stem growth were more strongly controlled by the atmospheric environment, than by soil water content. We conclude that as a response to the seasonal development of ΔW a shift in carbon allocation from aboveground

  10. Long-term DOC-leaching from a temperate Scots pine forest (Brasschaat, Belgium).

    NASA Astrophysics Data System (ADS)

    Gielen, B.; Neirynck, J.; Janssens, I. A.

    2009-04-01

    The carbon and water balance of terrestrial ecosystems are tightly coupled. Part of the assimilated carbon is leached from the ecosystem as dissolved organic carbon (DOC). These DOC-fluxes from the ecosystem are highly uncertain and are not incorporated in most process-based models. Therefore the focus of this study is to determine the drivers of the interannual and seasonal variability of the DOC-leaching. The study site is located 20km NE of Antwerp, near Brasschaat (Belgium) and consists of an 80-year-old even aged Scots pine (Pinus sylvestris L.) stand, which belongs to a larger mixed coniferous/deciduous forest and it is part of the ICP-II and Fluxnet/CarboEurope-IP networks since 1997. We simulated the different components of the water balance (transpiration, soil evaporation canopy evaporation, soil water content, runoff and leaching) with a combination of field measurements (sap flow, eddy covariance, TDR's) and the ORCHIDEE model. DOC concentrations were measured monthly in the trough fall and at four depths in the soil from the year 2000 onwards. Here we report estimates of DOC-leaching for a six year period (2000-2006) and assess its importance in the total carbon balance of the ecosystem. Results indicate that on average 10% of yearly NEE (as measured with eddy covariance measurements) is lost as DOC in the soil. We further looked at the drivers responsible for seasonal and interannual variation of the DOC-leaching. Logically, water leaching is the main driver of the DOC-leaching, for both the seasonal and the interannual variability. The remaining variation in the DOC leaching is affected by soil temperature and pH. DOC concentrations are highest in the upper soil layer and gradually decrease with depth. This could be explained by part of the DOC being respired as CO2 and part being retained in the soil matrix by Al and Fe-oxides adsorption. Future climate scenarios predict drier summer periods and more precipitation during the winter for the north

  11. Chemodiversity of a Scots pine stand and implications for terpene air concentrations

    NASA Astrophysics Data System (ADS)

    Bäck, J.; Aalto, J.; Henriksson, M.; Hakola, H.; He, Q.; Boy, M.

    2012-02-01

    Atmospheric chemistry in background areas is strongly influenced by natural vegetation. Coniferous forests are known to produce large quantities of volatile vapors, especially terpenes. These compounds are reactive in the atmosphere, and contribute to the formation and growth of atmospheric new particles. Our aim was to analyze the variability of mono- and sesquiterpene emissions between Scots pine trees, in order to clarify the potential errors caused by using emission data obtained from only a few trees in atmospheric chemistry models. We also aimed at testing if stand history and seed origin has an influence on the chemotypic diversity. The inherited, chemotypic variability in mono- and sesquiterpene emission was studied in a seemingly homogeneous 48 yr-old stand in Southern Finland, where two areas differing in their stand regeneration history could be distinguished. Sampling was conducted in August 2009. Terpene concentrations in the air had been measured at the same site for seven years prior to branch sampling for chemotypes. Two main compounds, α-pinene and Δ3-carene formed together 40-97% of the monoterpene proportions in both the branch emissions and in the air concentrations. The data showed a bimodal distribution in emission composition, in particular in Δ3-carene emission within the studied population. 10% of the trees emitted mainly α-pinene and no Δ3-carene at all, whereas 20% of the trees where characterized as high Δ3-carene emitters (Δ3-carene forming >80% of total emitted monoterpene spectrum). An intermediate group of trees emitted equal amounts of both α-pinene and Δ3-carene. The emission pattern of trees at the area established using seeding as the artificial regeneration method differed from the naturally regenerated or planted trees, being mainly high Δ3-carene emitters. Some differences were also seen in e.g. camphene and limonene emissions between chemotypes, but sesquiterpene emissions did not differ significantly between trees

  12. Mountain pine beetle host-range expansion threatens the boreal forest.

    PubMed

    Cullingham, Catherine I; Cooke, Janice E K; Dang, Sophie; Davis, Corey S; Cooke, Barry J; Coltman, David W

    2011-05-01

    The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, in part due to the difficulty in distinguishing the parentals and their hybrids. We tested the utility of a panel of microsatellite loci optimized for both species to classify lodgepole pine, jack pine and their hybrids using simulated data. We were able to accurately classify simulated individuals, and hence applied these markers to identify the ancestry of attacked trees. Here we show for the first time successful MPB attack in natural jack pine stands at the leading edge of the epidemic. This once unsuitable habitat is now a novel environment for MPB to exploit, a potential risk which could be exacerbated by further climate change. The consequences of host-range expansion for the vast boreal ecosystem could be significant. PMID:21457381

  13. Mountain pine beetle host-range expansion threatens the boreal forest

    PubMed Central

    Cullingham, Catherine I; Cooke, Janice E K; Dang, Sophie; Davis, Corey S; Cooke, Barry J; Coltman, David W

    2011-01-01

    The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, in part due to the difficulty in distinguishing the parentals and their hybrids. We tested the utility of a panel of microsatellite loci optimized for both species to classify lodgepole pine, jack pine and their hybrids using simulated data. We were able to accurately classify simulated individuals, and hence applied these markers to identify the ancestry of attacked trees. Here we show for the first time successful MPB attack in natural jack pine stands at the leading edge of the epidemic. This once unsuitable habitat is now a novel environment for MPB to exploit, a potential risk which could be exacerbated by further climate change. The consequences of host-range expansion for the vast boreal ecosystem could be significant. PMID:21457381

  14. Tree rings of Scots pine ( Pinus sylvestris L.) as a source of information about past climate in northern Poland

    NASA Astrophysics Data System (ADS)

    Koprowski, Marcin; Przybylak, Rajmund; Zielski, Andrzej; Pospieszyńska, Aleksandra

    2012-01-01

    Scots pine ( Pinus sylvestris) is a very common tree in Polish forests, and therefore was widely used as timber. A relatively large amount of available wood allowed a long-term chronology to be built up and used as a source of information about past climate. The analysis of reconstructed indexed values of mean temperature in 51-year moving intervals allowed the recognition of the coldest periods in the years 1207-1346, 1383-1425, 1455-1482, 1533-1574, 1627-1646, and 1694-1785. The analysis of extreme wide and narrow rings forms a complementary method of examining climatic data within tree rings. The tree ring widths, early wood and late wood widths of 16 samples were assessed during the period 1581-1676. The most apparent effect is noted in the dry summer of 1616. According to previous research and our findings, temperature from February to March seems to be one of the most stable climatic factors which influenced pine growth in Poland. Correlation coefficients in the calibration and validation procedure gave promising results for temperature reconstruction from the pine chronology.

  15. Tree rings of Scots pine (Pinus sylvestris L.) as a source of information about past climate in northern Poland.

    PubMed

    Koprowski, Marcin; Przybylak, Rajmund; Zielski, Andrzej; Pospieszyńska, Aleksandra

    2012-01-01

    Scots pine (Pinus sylvestris) is a very common tree in Polish forests, and therefore was widely used as timber. A relatively large amount of available wood allowed a long-term chronology to be built up and used as a source of information about past climate. The analysis of reconstructed indexed values of mean temperature in 51-year moving intervals allowed the recognition of the coldest periods in the years 1207-1346, 1383-1425, 1455-1482, 1533-1574, 1627-1646, and 1694-1785. The analysis of extreme wide and narrow rings forms a complementary method of examining climatic data within tree rings. The tree ring widths, early wood and late wood widths of 16 samples were assessed during the period 1581-1676. The most apparent effect is noted in the dry summer of 1616. According to previous research and our findings, temperature from February to March seems to be one of the most stable climatic factors which influenced pine growth in Poland. Correlation coefficients in the calibration and validation procedure gave promising results for temperature reconstruction from the pine chronology. PMID:21174127

  16. [Population-genetic variation in Scots pine Pinus sylvestris L. from the main forest regions of Ukraine].

    PubMed

    Korshikov, I I; Kalafat, L A; Pirko, Ia V; Velikorid'ko, T I

    2005-02-01

    Using electrophoretic analysis of 22 isozyme loci controlling ten enzyme systems, we studied intrapopulation and interpopulation variation of Scots pine Pinus sylvestris L. in the main forest regions of Ukraine. In 15 of the populations examined, 76.5% of genes were polymorphic, and an average plant was shown to be heterozygous at 23.4% of the genes. The lowest and highest values of major polymorphism parameters were characteristic of respectively the relic populations of Ukrainian Carpathians and the populations from the steppe and forest-steppe zones. Nei's genetic distances between the populations varied from 0.006 to 0.031 (on average 0.016). Cluster analysis failed to show clear trends in the population distribution relative to their geographical position. PMID:15810611

  17. Impact of timber felling on the ambient monoterpene concentration of a Scots pine ( Pinus sylvestris L.) forest

    NASA Astrophysics Data System (ADS)

    Räisänen, Tommi; Ryyppö, Aija; Kellomäki, Seppo

    The biogenic VOC emissions from the forests in Finland are dominated by monoterpenes. Annually, 4000-5500 km 2 of forests are felled, which corresponds to 2-3% of the total forest land. Damaging plant organs has been found to increase the terpene emissions of conifers, and therefore tree cuttings can be expected to increase monoterpene emissions from a managed site. The aim of this study was to evaluate the effects of felling of Scots pine timber on the ambient monoterpene concentration of forest air below the canopy layer. To achieve this, three experimental plots (diameter 25 m) established in an even aged Scots pine stand (ca. 40 years) were felled manually in June 8-9 2004 with different intensities: one was clear-cut and two thinned with removal of 30% and 60% of the tree basal area. The felled biomass was left at the plots for the measurement period of June-September. The aerial monoterpene concentration was increased 2-3 fold by clear-cutting during the first 7 weeks after the felling. The increment of concentration due to the clear-cut was greater than in the thinnings, which also increased the concentration significantly compared to the control plot in untouched forest. The last concentration observations in late-September (15 weeks after felling) showed negligible differences between the plots. The amount of logging residue left at the site was respectively largest at the clear-cut plot, and the residue is considered to be the most important factor explaining the increment of the monoterpene concentration. The aerial monoterpene concentration cannot directly be used to describe the monoterpene flux of the site, and the actual increment of emitted monoterpenes due to the fellings remain unclear. However, the significant increase in the ambient concentration induced by the felling implies that there is a great potential impact on local or even regional atmospheric chemistry.

  18. Influence of canopy traits on spatio-temporal variability of throughfall in Mediterranean Downy oak and Scots pine stands

    NASA Astrophysics Data System (ADS)

    Llorens, Pilar; Garcia-Estringana, Pablo; Latron, Jérôme; Molina, Antonio J.; Gallart, Francesc

    2014-05-01

    The spatio-temporal variability of throughfall is the result of the interaction of biotic factors, related to the canopy traits, and abiotic factors, linked to the meteorological conditions. This variability may lead to significant differences in the volume of water and solutes that reach the ground in each location, and beyond in the hydrological and biogeochemical dynamics of forest soils. Two forest stands in Mediterranean climatic conditions were studied to analyse the role of biotic and abiotic factors in the temporal and spatial redistribution of throughfall. The monitored stands are a Downy oak forest (Quercus pubescens) and a Scots pine forest (Pinus sylvestris), both located in the Vallcebre research catchments (NE Spain, 42º 12'N, 1º 49'E). The study plots are representative of Mediterranean mountain areas with spontaneous afforestation by Scots pine as a consequence of the abandonment of agricultural terraces, formerly covered by Downy oaks. The monitoring design of each plot consisted of a set of 20 automatic rain recorders and 40 automatic soil moisture probes located below the canopy. 100 hemispheric photographs of the canopy were used to place the instruments at representative locations (in terms of canopy cover) within the plot. Bulk rainfall, stemflow and meteorological conditions above the forest cover were also automatically recorded. Canopy cover as well as biometric characteristics of the plots were also regularly measured. The results indicate a temporal persistence of throughfall in both stands, as observed elsewhere. However, for the oak plot the seasonal evolution of canopy traits added additional variability, with higher variability in summer and different locations of wet and dry spots depending on the season. Furthermore, this work investigates the influence of canopy structure on the spatial variability of throughfall by analysing a large set of forest parameters, from main canopy traits to detailed leaves and wood characteristics

  19. Testing phenotypic trade-offs in the chemical defence strategy of Scots pine under growth-limiting field conditions.

    PubMed

    Villari, Caterina; Faccoli, Massimo; Battisti, Andrea; Bonello, Pierluigi; Marini, Lorenzo

    2014-09-01

    Plants protect themselves from pathogens and herbivores through fine-tuned resource allocation, including trade-offs among resource investments to support constitutive and inducible defences. However, empirical research, especially concerning conifers growing under natural conditions, is still scarce. We investigated the complexity of constitutive and induced defences in a natural Scots pine (Pinus sylvestris L.) stand under growth-limiting conditions typical of alpine environments. Phenotypic trade-offs at three hierarchical levels were tested by investigating the behaviour of phenolic compounds and terpenoids of outer bark and phloem. We tested resource-derived phenotypic correlations between (i) constitutive and inducible defences vs tree ring growth, (ii) different constitutive defence metabolites and (iii) constitutive concentration and inducible variation of individual metabolites. Tree ring growth was positively correlated only with constitutive concentration of total terpenoids, and no overall phenotypic trade-offs between different constitutive defensive metabolites were found. At the lowest hierarchical level tested, i.e., at the level of relationship between constitutive and inducible variation of individual metabolites, we found that different compounds displayed different behaviours; we identified five different defensive metabolite response types, based on direction and strength of the response, regardless of tree age and growth rate. Therefore, under growth-limiting field conditions, Scots pine appears to utilize varied and complex outer bark and phloem defence chemistry, in which only part of the constitutive specialized metabolism is influenced by tree growth, and individual components do not appear to be expressed in a mutually exclusive manner in either constitutive or inducible metabolism. PMID:25194142

  20. Combined effects of ozone and nitrogen on secondary compounds, amino acids, and aphid performance in Scots pine

    SciTech Connect

    Kainulainen, P.; Holopainen, J.K.; Holopainen, T.

    2000-02-01

    Combined effects of O{sub 3} and N supply on Scots pine (Pinus sylvestris L.) were studied in two separate growth chamber experiments exposing seedlings to 0, 0.075, 0.15, and 0.3 {micro}L/L of O{sub 3} during 8 h/d, 5 d/wk for a period of 5 wk. Seedlings were fertilized with low, medium, and high levels of N. Ozone and N availability affected concentrations of several primary and secondary metabolites. More changes on metabolites were detected in Exp. 1 (with seedlings ceasing their annual growth) than in Exp. 2 (with seedlings actively growing). Overall, high O{sub 3} exposure levels significantly decreased concentrations of monoterpenes and increased concentrations of resin acids. Concentrations of total phenolics were not affected by O{sub 3} exposure. Mostly lower concentrations of monoterpenes and resin acids were found at a medium N-fertilization level than at low and high N-fertilization levels, while total phenolic concentration decreased by enhanced N availability. In Exp. 1, significantly elevated concentrations of free amino acids were found at O{sub 3} concentration of 0.3 {micro}L/L. Nitrogen availability did not have remarkable effects on amino acid concentrations. In Exp. 1, both {sub 3} and N had a significant effect on the MRGR of the aphid Schizolachnus pineti. In Exp. 2, the weight of the females and nymphs and the total number of reproduced nymphs were significantly affected by O{sub 3} and N. Only a few interaction effects were found, suggesting that the N supply does not significantly modify O{sub 3}-induced effects on studied primary and secondary compounds and aphid performance in Scots pine seedlings.

  1. Long term effects of forest fires to soil C content and soil CO_{2} efflux in hemiboreal Scots pine forests of Estonia.

    NASA Astrophysics Data System (ADS)

    Köster, Kajar; Metslaid, Marek; Orumaa, Argo; Parro, Kristi; Jõgiste, Kalev; Berninger, Frank; Pumpanen, Jukka; Köster, Egle

    2016-04-01

    Fire is the primary process which organizes the physical and biological attributes of the boreal biome and influences energy flows and biogeochemical cycles, particularly the carbon (C) cycle. Especially the soil organic matter pool in boreal forests is an important C storage with a long C turnover time, but fire frequencies that are expected to increase with changing climate, can change that. We compared the initial recovery of C pools and CO2 efflux following fire disturbances in Scots pine (Pinus sylvesteris L.) stands with different time since fire. The study areas are located in hemiboreal vegetation zone, in northwestern Estonia, in Vihterpalu. Six areas (with extensive fires 200 ha and more) were chosen for study: fire in a year 1837, 1940, 1951, 1982, 1997, and 2008. In all areas we are dealing with stand replacing fires where all (or almost all) of the stand was destroyed by fire. On every area we established three permanent sample plots. Soil respiration was measured manually from all sample plots (measuring interval of two - three weeks). Manual chamber measurements are performed on 5 collars (north - south orientated and the distance between collars is 5 m) at each sample plot from May till November 2015. To characterize the soil C and N content and fine root biomass at the sites, 5 soil cores (0.5 m long and 0.05 m in diameter) were taken from each sample plot. Our results show that forest fire has a substantial effect on the C content in the top soil layer, but not in the humus layer and in mineral soil layers. Soil respiration showed similar chronological response to the time since the forest fire indicating that substantial proportion of the respiration was originating from the very top of the soil. Soil respiration values were lowest on the area where the fire was in a year 2008 and the respiration values followed also seasonal pattern being highest in August and lowest in May and November. The CO2 effluxes were lowest on newly burned area through

  2. The lodgepole × jack pine hybrid zone in Alberta, Canada: a stepping stone for the mountain pine beetle on its journey East across the boreal forest?

    PubMed

    Lusebrink, Inka; Erbilgin, Nadir; Evenden, Maya L

    2013-09-01

    Historical data show that outbreaks of the tree killing mountain pine beetle are often preceded by periods of drought. Global climate change impacts drought frequency and severity and is implicated in the range expansion of the mountain pine beetle into formerly unsuitable habitats. Its expanded range has recently reached the lodgepole × jack pine hybrid zone in central Alberta, Canada, which could act as a transition from its historical lodgepole pine host to a jack pine host present in the boreal forest. This field study tested the effects of water limitation on chemical defenses of mature trees against mountain pine beetle-associated microorganisms and on beetle brood success in lodgepole × jack pine hybrid trees. Tree chemical defenses as measured by monoterpene emission from tree boles and monoterpene concentration in needles were greater in trees that experienced water deficit compared to well-watered trees. Myrcene was identified as specific defensive compound, since it significantly increased upon inoculation with dead mountain pine beetles. Beetles reared in bolts from trees that experienced water deficit emerged with a higher fat content, demonstrating for the first time experimentally that drought conditions benefit mountain pine beetles. Further, our study demonstrated that volatile chemical emission from tree boles and phloem chemistry place the hybrid tree chemotype in-between lodgepole pine and jack pine, which might facilitate the host shift from lodgepole pine to jack pine. PMID:23955061

  3. Chronic irradiation of Scots pine trees (Pinus sylvestris) in the Chernobyl exclusion zone: dosimetry and radiobiological effects.

    PubMed

    Yoschenko, Vasyl I; Kashparov, Valery A; Melnychuk, Maxim D; Levchuk, Svjatoslav E; Bondar, Yulia O; Lazarev, Mykola; Yoschenko, Maria I; Farfán, Eduardo B; Jannik, G Timothy

    2011-10-01

    To identify effects of chronic internal and external radiation exposure for components of terrestrial ecosystems, a comprehensive study of Scots pine trees in the Chernobyl Exclusion Zone was performed. The experimental plan included over 1,100 young trees (up to 20 y old) selected from areas with varying levels of radioactive contamination. These pine trees were planted after the 1986 Chernobyl Nuclear Power Plant accident mainly to prevent radionuclide resuspension and soil erosion. For each tree, the major morphological parameters and radioactive contamination values were identified. Cytological analyses were performed for selected trees representing all dose rate ranges. A specially developed dosimetric model capable of taking into account radiation from the incorporated radionuclides in the trees was developed for the apical meristem. The calculated dose rates for the trees in the study varied within three orders of magnitude, from close to background values in the control area (about 5 mGy y(-1)) to approximately 7 Gy y(-1) in the Red Forest area located in the immediate vicinity of the Chernobyl Nuclear Power Plant site. Dose rate/effect relationships for morphological changes and cytogenetic defects were identified, and correlations for radiation effects occurring on the morphological and cellular level were established. PMID:21878765

  4. CHRONIC IRRADIATION OF SCOTS PINE TREES (PINUS SYLVESTRIS) IN THE CHERNOBYL EXCLUSION ZONE: DOSIMETRY AND RADIOBIOLOGICAL EFFECTS

    SciTech Connect

    Farfan, E.; Jannik, T.

    2011-10-01

    To identify effects of chronic internal and external radiation exposure for components of terrestrial ecosystems, a comprehensive study of Scots pine trees in the Chernobyl Exclusion Zone was performed. The experimental plan included over 1,100 young trees (up to 20 years old) selected from areas with varying levels of radioactive contamination. These pine trees were planted after the 1986 Chernobyl Nuclear Power Plant accident mainly to prevent radionuclide resuspension and soil erosion. For each tree, the major morphological parameters and radioactive contamination values were identified. Cytological analyses were performed for selected trees representing all dose rate ranges. A specially developed dosimetric model capable of taking into account radiation from the incorporated radionuclides in the trees was developed for the apical meristem. The calculated dose rates for the trees in the study varied within three orders of magnitude, from close to background values in the control area (about 5 mGy y{sup -1}) to approximately 7 Gy y{sup -1} in the Red Forest area located in the immediate vicinity of the Chernobyl Nuclear Power Plant site. Dose rate/effect relationships for morphological changes and cytogenetic defects were identified and correlations for radiation effects occurring on the morphological and cellular level were established.

  5. Changes in cellular structures and enzymatic activities during browning of Scots pine callus derived from mature buds.

    PubMed

    Laukkanen, Hanna; Rautiainen, Lea; Taulavuori, Erja; Hohtola, Anja

    2000-04-01

    Visible browning is a typical feature of callus cultures derived from shoot tips of mature Scots pine (Pinus sylvestris L.). Because the ability of callus to regenerate is low, we determined the effect of browning on growth and changes in cellular structure during culture. Striking alterations in cellular structure were detected by LM (light microscopy), EM (electron microscopy) and SEM (scanning electron microscopy). Accumulation of phenolic substances was shown by histochemical staining. Staining for beta-glucosidase activity of soluble proteins that had been subjected to polyacrylamide gel electrophoresis indicated lignification of cells. The measured growth rate of callus was low compared with a hypothetical growth curve. Peroxidase activity increased rapidly soon after the start of the culture period, but especially between the second and third weeks of culture. At this time, the degradation of cell membranes and browning began coincident with the loss of chlorophyll. We conclude that browning is associated with cell disorganization and eventual cell death, making tissue culture of mature pine especially difficult. PMID:12651442

  6. Shift in ectomycorrhizal community composition in Scots pine (Pinus sylvestris L.) seedling roots as a response to nickel deposition and removal of lichen cover.

    PubMed

    Markkola, A M; Ahonen-Jonnarth, U; Roitto, M; Strömmer, R; Hyvärinen, M

    2002-01-01

    Scots pine seedlings were exposed to wet-deposited nickel (Ni) and removal of lichen cover in a dry heath Scots pine forest. Ni deposition affected the colonization of roots by indigenous ectomycorrhizal fungi in contrasting ways in intact and skimmed quadrats. Highest frequencies of tubercle morphotypes of ectomycorrhiza were found in quadrats exposed to 100 mg m(-2) year(-1) Ni in lichen covered treatment, while in skimmed quadrats these peaked after the treatment with 10 mg Ni m(-2) year(-1). Removal of the lichen layer increased the value of diversity index (H') of ectomycorrhizal fungal community, probably due to the increase in the evenness of the morphotype distribution. Lichen removal seemed also to improve the condition of the short roots, as the frequencies of poor and senescent short roots were decreased by the removal. PMID:12442803

  7. The use of plants as regular food in ancient subarctic economies: a case study based on Sami use of Scots pine innerbark.

    PubMed

    Bergman, Ingela; Östlund, Lars; Zackrisson, Olle

    2004-01-01

    This study combines ethnological, historical, and dendroecological data from areas north of the Arctic Circle to analyze cultural aspects of Sami use of Scots pine (Pinus sylvestris L.) inner bark as regular food. Bark was peeled in June when trees were at the peak of sapping, leaving a strip of undamaged cambium so the tree survived. As a result, it is possible to date bark-peeling episodes using dendrochronology. The paper argues that the use of Scots pine inner bark reflects Sami religious beliefs, ethical concerns, and concepts of time, all expressed in the process of peeling the bark. A well-developed terminology and a set of specially designed tools reveal the technology involved in bark peeling. Consistent patterns with respect to the direction and size of peeling scars found across the region demonstrate common values and standards. Peeling direction patterns and ceremonial meals relating to bark probably reflect ritual practices connected to the sun deity, Biejvve. PMID:21774149

  8. Artificial recharge of groundwater through sprinkling infiltration: impacts on forest soil and the nutrient status and growth of Scots pine.

    PubMed

    Nöjd, Pekka; Lindroos, Antti-Jussi; Smolander, Aino; Derome, John; Lumme, Ilari; Helmisaari, Heljä-Sisko

    2009-05-01

    We studied the chemical changes in forest soil and the effects on Scots pine trees caused by continuous sprinkling infiltration over a period of two years, followed by a recovery period of two years. Infiltration increased the water input onto the forest soil by a factor of approximately 1000. After one year of infiltration, the pH of the organic layer had risen from about 4.0 to 6.7. The NH(4)-N concentration in the organic layer increased, most probably due to the NH(4) ions in the infiltration water, as the net N mineralization rate did not increase. Sprinkling infiltration initiated nitrification in the mineral soil. Macronutrient concentrations generally increased in the organic layer and mineral soil. An exception, however, was the concentration of extractable phosphorus, which decreased strongly during the infiltration period and did not show a recovery within two years. The NO(3)-N and K concentrations had reverted back to their initial level during the two-year recovery period, while the concentrations of Ca, Mg and NH(4)-N were still elevated. Nutrient concentrations in the pine needles increased on the infiltrated plots. However, the needle P concentration increased, despite the decrease in plant-available P in the soil. Despite the increase in the nutrient status, there were some visible signs of chlorosis in the current-year needles after two years of infiltration. The radial growth of the pines more than doubled on the infiltrated plots, which suggests that the very large increase in the water input onto the forest floor had no adverse effect on the functioning of the trees. However, a monitoring period of four years is not sufficient for detecting potential long term detrimental effects on forest trees. PMID:19269680

  9. Rapid changes in the range limits of Scots pine 4000 years ago

    SciTech Connect

    Gear, A.J.; Huntley, B. )

    1991-02-01

    Paleoecological data provide estimates of response rates to past climate changes. Fossil Pinus sylvestris stumps in far northern Scotland demonstrate former presence of pine trees where conventional pollen evidence of pine forests is lacking. Radiocarbon, dendrochronological, and fine temporal-resolution palynological data show that pine forest were present for about four centuries some 4,000 years ago; the forests expanded and then retreated rapidly some 70 to 80 kilometers. Despite the rapidity of this response to climate change, it occurred at rates slower by an order of magnitude than those necessary to maintain equilibrium with forecast climate changes attributed to the greenhouse effect.

  10. Effect of attract and kill formulations and application rates on trap catches of European pine shoot moth (Lepidoptera: Tortricidae) and shoot damage in Scots pine saplings.

    PubMed

    Sukovata, Lidia; Kolk, Andrzej; Cieślak, Marek

    2004-10-01

    Attract and kill technology was tested for management of European pine shoot moth, Rhyacionia buoliana (Denis & Schiffermüller), in 4-6-yr-old Scots pine, Pinus sylvestris L., plantations managed by Jablonna and Pultusk Forest Districts, Poland. In 2001, two formulations based on ricinoleic acid and hydrocarbon fraction (petroleum jelly) in combination with (E)-9-dodecenyl acetate, the sex pheromone of the pine shoot moth; permethrin as a contact insecticide; and Tinuvin UV absorber were used. In 2002, different formulations and application rates of the attracticide based on petroleum jelly were tested. Significantly reduced trap catches occurred in plots treated with three attracticide formulations [Rhykil-1 (with Tinuvin UV absorber), Rhykil-2 (with a new UV absorber, 3,3'-dihydroxy-2,2'-bipyridyl), and Rhykil-3 (without the insecticide)] at 3,000 droplets per hectare in comparison with those in control plots, suggesting that all formulations were highly effective. Significantly lower catches than in control plots also were observed when Rhykil-1 was applied at 1000, 2,000, and 3,000 droplets per hectare. However, only slight reduction of shoot damage in treated plots was observed in both experiments. The formulation without the insecticide had similar efficacy to that of the formulation combined with the insecticide. In 2003, the Rhykil-2 attracticide was tested at 250, 500, and 1000 droplets per hectare. Although there were no significant differences in trap catches between treated and control plots, shoot damage level was reduced substantially in all treated plots. These results suggest that attract and kill technology may be used at rates lower than 1000 droplets per hectare for management of R. buoliana; however, its "kill" effect should be confirmed in further studies. PMID:15568351

  11. Soil respiration shifts as drought-induced tree substitution advances from Scots pine to Holm oak forest

    NASA Astrophysics Data System (ADS)

    Barba, Josep; Curiel Yuste, Jorge; Poyatos, Rafael; Janssens, Ivan A.; Lloret, Francisco

    2014-05-01

    There is more and more evidences that the current global warming trend and the increase of frequency and intensity of drought events during the last decades in the Northern hemisphere are currently producing an increment of drought-induced forest die-off events, being the Mediterranean region one of the most affected areas. This drought-induced mortality could lead in a vegetation shift with unpredicted consequences in carbon pools, where soils are the most determinant factor in this carbon balance as they contain over two-thirds of carbon on forest ecosystems. There are several uncertainties related on the interaction between soil, environmental conditions and vegetation shifts that could modify their capability to be net carbon sinks or sources in a warming context. We studied soil respiration and its heterotrophic (RH) and autotrophic (Ra) (split in fine roots [Rr] and mycorrhizal respiration [Rs]) components in a mixed Mediterranean forest where Scots pine (Pinus sylvestris L.) are suffering from drought-induced die-off and replaced by Holm oak (Quercus ilex L.) as the dominant tree species. Soil respiration fluxes and its fractions were measured every two weeks during one year at four stages of the substitution process (non defoliated pines [NDP], defoliated pines [DFP], dead pines [DP] and Holm oak [HO]), using the mesh exclusion method. The aims were (i) to describe soil respiration fluxes in a drought-induced secondary successional process, (ii) to test whether the changes in vegetation affected soil respiration fluxes and (iii) to determine the influence of environmental and abiotic variables on the different soil respiration fractions. Total soil respiration was 10.10±6.17 TC ha-1 y-1, RH represented the 67% of the total, Ra represented the 34% of the total, and Rr and Rs were the 22 and 12%, respectively. Significant differences were found in total soil respiration and RH between NDP and HO, being lower in HO than in NDP (34% in total and 48% in RH). No

  12. Nitrogen fertilizer factory effects on the amino acid and nitrogen content in the needles of Scots pine.

    PubMed

    Kupsinskiene, E

    2001-12-01

    The aim of the research was to evaluate the content of amino acids in the needles of Pinus sylvestris growing in the area affected by a nitrogen fertilizer factory and to compare them with other parameters of needles, trees, and sites. Three young-age stands of Scots pine were selected at a distance of 0.5 km, 5 km, and 17 km from the factory. Examination of the current-year needles in winter of the year 2000 revealed significant (p < 0.05) differences between the site at a 0.5-km distance from the factory and the site at a 17-km distance from the factory--with the site closest to the factory showing the highest concentrations of protein (119%), total arginine (166%), total other amino acids (depending on amino acid, the effect ranged between 119 and 149%), free arginine (771%), other free amino acids (glutamic acid, threonine, serine, lysine--depending on amino acid, the effect ranged between 162 and 234%), also the longest needles, widest diameter, largest surface area, and heaviest dry weight (respectively, 133, 110, 136, and 169%). The gradient of nitrogen concentration in the needles was assessed on the selected plots over the period of 1995-2000, with the highest concentration (depending on year, 119 to 153%) documented in the site located 0.5 km from the factory. Significant correlations were determined between the total amino acid contents (r = 0.448 -0.939, p < 0.05), some free amino acid (arginine, aspartic acid, glutamic acid, lysine, threonine, and serine) contents (r = 0.418 - 0.975, p < 0.05), and air pollutant concentration at the sites, the distance between the sites and the factory, and characteristics of the needles. No correlation was found between free or total arginine content and defoliation or retention of the needles. In conclusion, it was revealed that elevated mean monthly concentration of ammonia (26 microg m(-3)) near the nitrogen fertilizer factory caused changes in nitrogen metabolism, especially increasing (nearly eight times

  13. Ozone uptake and effects on transpiration, net photosynthesis, and dark respiration in Scots pine. [Pinus sylvestris L

    SciTech Connect

    Skaerby, L.; Troeng, E.; Bostroem, C.

    1987-09-01

    Ozone uptake, transpiration, net photosynthesis, and dark respiration were studied in the field by using an open gas exchange system in a 20-year-old stand of Scots pine (Pinus sylvestris L.). A current shoot was treated with ozone concentrations ranging from 120 to 400 ..mu..g x m/sup -3/ during one month. During daytime there was a linear relationship between ozone concentration and ozone uptake, and the deposition rate varied between 0.05 and 0.13 cm x s/sup -1/. Ozone at the highest concentrations seemed to decrease transpiration somewhat during daytime. At night, ozone was taken up only at the highest concentration. Both transpiration and stomatal conductance increased at night when ozone concentration was 250..mu..g x m/sup -3/ and higher. There was no significant influence on the net photosynthetic performance during exposure to ozone. Dark respiration, however, increased throughout the experimental period, and the accumulated respiration was about 60% higher for the ozone-exposed shoot at the end of the experiment.

  14. Branch age and light conditions determine leaf-area-specific conductivity in current shoots of Scots pine.

    PubMed

    Grönlund, Leila; Hölttä, Teemu; Mäkelä, Annikki

    2016-08-01

    Shoot size and other shoot properties more or less follow the availability of light, but there is also evidence that the topological position in a tree crown has an influence on shoot development. Whether the hydraulic properties of new shoots are more regulated by the light or the position affects the shoot acclimation to changing light conditions and thereby to changing evaporative demand. We investigated the leaf-area-specific conductivity (and its components sapwood-specific conductivity and Huber value) of the current-year shoots of Scots pine (Pinus sylvestris L.) in relation to light environment and topological position in three different tree classes. The light environment was quantified in terms of simulated transpiration and the topological position was quantified by parent branch age. Sample shoot measurements included length, basal and tip diameter, hydraulic conductivity of the shoot, tracheid area and density, and specific leaf area. In our results, the leaf-area-specific conductivity of new shoots declined with parent branch age and increased with simulated transpiration rate of the shoot. The relation to transpiration demand seemed more decisive, since it gave higher R(2) values than branch age and explained the differences between the tree classes. The trend of leaf-area-specific conductivity with simulated transpiration was closely related to Huber value, whereas the trend of leaf-area-specific conductivity with parent branch age was related to a similar trend in sapwood-specific conductivity. PMID:27217528

  15. Balancing the risks of hydraulic failure and carbon starvation: a twig scale analysis in declining Scots pine

    PubMed Central

    Torres‐Ruiz, José M.; Poyatos, Rafael; Martinez‐Vilalta, Jordi; Meir, Patrick; Cochard, Hervé; Mencuccini, Maurizio

    2015-01-01

    Abstract Understanding physiological processes involved in drought‐induced mortality is important for predicting the future of forests and for modelling the carbon and water cycles. Recent research has highlighted the variable risks of carbon starvation and hydraulic failure in drought‐exposed trees. However, little is known about the specific responses of leaves and supporting twigs, despite their critical role in balancing carbon acquisition and water loss. Comparing healthy (non‐defoliated) and unhealthy (defoliated) Scots pine at the same site, we measured the physiological variables involved in regulating carbon and water resources. Defoliated trees showed different responses to summer drought compared with non‐defoliated trees. Defoliated trees maintained gas exchange while non‐defoliated trees reduced photosynthesis and transpiration during the drought period. At the branch scale, very few differences were observed in non‐structural carbohydrate concentrations between health classes. However, defoliated trees tended to have lower water potentials and smaller hydraulic safety margins. While non‐defoliated trees showed a typical response to drought for an isohydric species, the physiology appears to be driven in defoliated trees by the need to maintain carbon resources in twigs. These responses put defoliated trees at higher risk of branch hydraulic failure and help explain the interaction between carbon starvation and hydraulic failure in dying trees. PMID:25997464

  16. Fungal succession in relation to volatile organic compounds emissions from Scots pine and Norway spruce leaf litter-decomposing fungi

    NASA Astrophysics Data System (ADS)

    Isidorov, Valery; Tyszkiewicz, Zofia; Pirożnikow, Ewa

    2016-04-01

    Leaf litter fungi are partly responsible for decomposition of dead material, nutrient mobilization and gas fluxes in forest ecosystems. It can be assumed that microbial destruction of dead plant materials is an important source of volatile organic compounds (VOCs) emitted into the atmosphere from terrestrial ecosystems. However, little information is available on both the composition of fungal VOCs and their producers whose community can be changed at different stages of litter decomposition. The fungal community succession was investigated in a litter bag experiment with Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) needle litter. The succession process can be divided into a several stages controlled mostly by changes in litter quality. At the very first stages of decomposition the needle litter was colonized by ascomycetes which can use readily available carbohydrates. At the later stages, the predominance of Trichoderma sp., the known producers of cellulolytic enzymes, was documented. To investigate the fungi-derived VOCs, eight fungi species were isolated. As a result of gas chromatographic analyses, as many as 75C2sbnd C15 fungal volatile compounds were identified. Most components detected in emissions were very reactive substances: the principal groups of VOCs were formed by monoterpenes, carbonyl compounds and aliphatic alcohols. It was found that production of VOCs by fungi is species specific: only 10 metabolites were emitted into the gas phase by all eight species. The reported data confirm that the leave litter decomposition is important source of reactive organic compounds under the forest canopy.

  17. Estimation of temporal and spatial variations in groundwater recharge in unconfined sand aquifers using Scots pine inventories

    NASA Astrophysics Data System (ADS)

    Ala-aho, P.; Rossi, P. M.; Kløve, B.

    2015-04-01

    Climate change and land use are rapidly changing the amount and temporal distribution of recharge in northern aquifers. This paper presents a novel method for distributing Monte Carlo simulations of 1-D sandy sediment profile spatially to estimate transient recharge in an unconfined esker aquifer. The modelling approach uses data-based estimates for the most important parameters controlling the total amount (canopy cover) and timing (thickness of the unsaturated zone) of groundwater recharge. Scots pine canopy was parameterized to leaf area index (LAI) using forestry inventory data. Uncertainty in the parameters controlling sediment hydraulic properties and evapotranspiration (ET) was carried over from the Monte Carlo runs to the final recharge estimates. Different mechanisms for lake, soil, and snow evaporation and transpiration were used in the model set-up. Finally, the model output was validated with independent recharge estimates using the water table fluctuation (WTF) method and baseflow estimation. The results indicated that LAI is important in controlling total recharge amount. Soil evaporation (SE) compensated for transpiration for areas with low LAI values, which may be significant in optimal management of forestry and recharge. Different forest management scenarios tested with the model showed differences in annual recharge of up to 100 mm. The uncertainty in recharge estimates arising from the simulation parameters was lower than the interannual variation caused by climate conditions. It proved important to take unsaturated thickness and vegetation cover into account when estimating spatially and temporally distributed recharge in sandy unconfined aquifers.

  18. [Genetic variability in Scots pine populations from the Bryansk region contaminated by radioactive pollutants as a result of the Chernobyl NPP accident].

    PubMed

    Geras'kin, S A; Vanina, Iu S; Dikarev, V G; Novikova, T A; Udalova, A A; Spiridonov, S I

    2009-01-01

    The method of isozymic analysis of megagametophytes is used for an estimation of genetic variability in populations of Scots pine (Pinus sylvestris L.), inhabiting contrast on the level of radioactive contamination (60-17800 Bq/kg on 137Cs) sites in the Bryansk region, undergone to radioactive pollution as a result of the Chernobyl accident. Values of all investigated parameters of genetic variability (heterozygosity, frequency of polymorphic loci, Jivotovski index) and frequencies of the mutations for loss of enzymatic activity increase with a doze absorbed by critical organs of pine trees. Presented data show that a high level of mutation occurrence is intrinsic for descendants (seeds) of pine trees in the investigated populations, and genetic diversity in the populations is essentially conditioned by radiation exposure. PMID:19507681

  19. Carbon and water vapour exchange in a recently burned east boreal jack pine stand, Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Nugent, K.; Strachan, I. B.

    2013-12-01

    The circumpolar boreal forest is an extensive carbon (C) reservoir, storing an estimated 88 petagrams (Pg) of C in vegetation biomass with an additional 471 PgC residing within the soil itself. In the North American boreal, fire disturbance acts as the main stand-renewing agent along an approximate 100-year return interval. However, recent studies suggest that fire intensity and severity are increasing, driven by disproportionate climate warming of the northern latitudes. While estimates of direct C emissions from combustion are becoming more accurate, indirect loss due to post-fire effects on decomposition and regeneration has only recently become a focus of research. Paradoxically, it has been estimated that post-fire C releases are in the order of three times the amount directly released during initial combustion. In this study, we examine carbon and water exchange in a 6-year old, post-burn, jack pine stand located in the eastern James Bay region of the Canadian boreal; an area currently under-represented in fire studies. Over 1.5 years, covering two growing seasons and the spring and fall transitions, we measured net CO2 and energy exchange at the ecosystem level using an eddy covariance tower, and supplemented this with chamber measurements of soil respiration. At this stage of recovery, while demonstrating diurnal and seasonal patterns of exchange, overall the site was a net source of C and water to the atmosphere with brief periods of C sink.

  20. Increased Needle Nitrogen Contents Did Not Improve Shoot Photosynthetic Performance of Mature Nitrogen-Poor Scots Pine Trees

    PubMed Central

    Tarvainen, Lasse; Lutz, Martina; Räntfors, Mats; Näsholm, Torgny; Wallin, Göran

    2016-01-01

    Numerous studies have shown that temperate and boreal forests are limited by nitrogen (N) availability. However, few studies have provided a detailed account of how carbon (C) acquisition of such forests reacts to increasing N supply. We combined measurements of needle-scale biochemical photosynthetic capacities and continuous observations of shoot-scale photosynthetic performance from several canopy positions with simple mechanistic modeling to evaluate the photosynthetic responses of mature N-poor boreal Pinus sylvestris to N fertilization. The measurements were carried out in August 2013 on 90-year-old pine trees growing at Rosinedalsheden research site in northern Sweden. In spite of a nearly doubling of needle N content in response to the fertilization, no effect on the long-term shoot-scale C uptake was recorded. This lack of N-effect was due to strong light limitation of photosynthesis in all investigated canopy positions. The effect of greater N availability on needle photosynthetic capacities was also constrained by development of foliar phosphorus (P) deficiency following N addition. Thus, P deficiency and accumulation of N in arginine appeared to contribute toward lower shoot-scale nitrogen-use efficiency in the fertilized trees, thereby additionally constraining tree-scale responses to increasing N availability. On the whole our study suggests that the C uptake response of the studied N-poor boreal P. sylvestris stand to enhanced N availability is constrained by the efficiency with which the additional N is utilized. This efficiency, in turn, depends on the ability of the trees to use the greater N availability for additional light capture. For stands that have not reached canopy closure, increase in leaf area following N fertilization would be the most effective way for improving light capture and C uptake while for mature stands an increased leaf area may have a rather limited effect on light capture owing to increased self-shading. This raises the

  1. Increased Needle Nitrogen Contents Did Not Improve Shoot Photosynthetic Performance of Mature Nitrogen-Poor Scots Pine Trees.

    PubMed

    Tarvainen, Lasse; Lutz, Martina; Räntfors, Mats; Näsholm, Torgny; Wallin, Göran

    2016-01-01

    Numerous studies have shown that temperate and boreal forests are limited by nitrogen (N) availability. However, few studies have provided a detailed account of how carbon (C) acquisition of such forests reacts to increasing N supply. We combined measurements of needle-scale biochemical photosynthetic capacities and continuous observations of shoot-scale photosynthetic performance from several canopy positions with simple mechanistic modeling to evaluate the photosynthetic responses of mature N-poor boreal Pinus sylvestris to N fertilization. The measurements were carried out in August 2013 on 90-year-old pine trees growing at Rosinedalsheden research site in northern Sweden. In spite of a nearly doubling of needle N content in response to the fertilization, no effect on the long-term shoot-scale C uptake was recorded. This lack of N-effect was due to strong light limitation of photosynthesis in all investigated canopy positions. The effect of greater N availability on needle photosynthetic capacities was also constrained by development of foliar phosphorus (P) deficiency following N addition. Thus, P deficiency and accumulation of N in arginine appeared to contribute toward lower shoot-scale nitrogen-use efficiency in the fertilized trees, thereby additionally constraining tree-scale responses to increasing N availability. On the whole our study suggests that the C uptake response of the studied N-poor boreal P. sylvestris stand to enhanced N availability is constrained by the efficiency with which the additional N is utilized. This efficiency, in turn, depends on the ability of the trees to use the greater N availability for additional light capture. For stands that have not reached canopy closure, increase in leaf area following N fertilization would be the most effective way for improving light capture and C uptake while for mature stands an increased leaf area may have a rather limited effect on light capture owing to increased self-shading. This raises the

  2. Increase of apatite dissolution rate by Scots pine roots associated or not with Burkholderia glathei PML1(12)Rp in open-system flow microcosms

    NASA Astrophysics Data System (ADS)

    Calvaruso, Christophe; Turpault, Marie-Pierre; Frey-Klett, Pascale; Uroz, Stéphane; Pierret, Marie-Claire; Tosheva, Zornitza; Kies, Antoine

    2013-04-01

    The release of nutritive elements through apatite dissolution represents the main source of phosphorus, calcium, and several micronutrients (e.g., Zn, Cu) for organisms in non-fertilized forest ecosystems. The aim of this study was to quantify, for the first time, the dissolution rate of apatite grains by tree roots that were or were not associated with a mineral weathering bacterial strain, and by various acids known to be produced by tree roots and soil bacterial strains in open-system flow microcosms. In addition, we explored whether the mobilization of trace elements (including rare earth elements) upon apatite dissolution was affected by the presence of trees and associated microorganisms. The dissolution rate of apatite by Scots pine plants that were or were not inoculated with the strain Burkholderia glathei PML1(12)Rp, and by inorganic (nitric) and organic (citric, oxalic and gluconic) acids at pH 5.5, 4.8, 3.8, 3.5, 3.0, and 2.0 was monitored in two controlled experiments: "plant-bacteria interaction" and "inorganic and organic acids". Analyses of the outlet solutions in the "plant-bacteria interaction" experiment showed that Scots pine roots and B. glathei PML1(12)Rp produced protons and organic acids such as gluconate, oxalate, acetate, and lactate. The weathering budget calculation revealed that Scots pines (with or without PML1(12)Rp) significantly increased (factor > 10) the release of Ca, P, As, Sr, Zn, U, Y, and rare earth elements such as Ce, La, Nd from apatite, compared to control abiotic treatment. Scanning electron microscopy observation confirmed traces of apatite dissolution in contact of roots. Most dissolved elements were taken up by Scots pine roots, i.e., approximately 50% of Ca, 70% of P, 30% of As, 70% of Sr, 90% of Zn, and 100% of U, Y, and rare earth elements. Interestingly, no significant additional effect due to the bacterial strain PML1(12)Rp on apatite dissolution and Scots pine nutrition and growth was observed. The "inorganic

  3. Effects of copper deficiency and copper toxicity on organogenesis and some physiological and biochemical responses of Scots pine (Pinus sylvestris L.) seedlings grown in hydroculture.

    PubMed

    Ivanov, Yury V; Kartashov, Alexander V; Ivanova, Alexandra I; Savochkin, Yury V; Kuznetsov, Vladimir V

    2016-09-01

    The morphological, physiological, and biochemical parameters of 6-week-old seedlings of Scots pine (Pinus sylvestris L.) were studied under deficiency (1.2 nM) and chronic exposure to copper (0.32, 1, 2.5, 5, and 10 μM CuSO4) in hydroculture. The deposit of copper in the seed allowed the seedlings to develop under copper deficiency without visible disruption of growth. The high sensitivity of Scots pine to the toxic effects of copper was shown, which manifested as a significant inhibition of growth and development. The loss of dominance of the main root and a strong inhibition of lateral root development pointed to a lack of adaptive reorganization of the root system architecture under copper excess. A preferential accumulation of copper in the root and a minor translocation in aerial organs confirmed that Scots pine belongs to a group of plants that exclude copper. Selective impairment in the absorption of manganese was discovered, under both deficiency and excess of copper in the nutrient solution, which was independent of the degree of development of the root system. Following 10 μM CuSO4 exposure, the absorption of manganese and iron from the nutrient solution was completely suppressed, and the development of seedlings was secured by the stock of these micronutrients in the seed. The absence of signs of oxidative stress in the seedling organs was shown under deficiency and excess of copper, as evidenced by the steady content of malondialdehyde and 4-hydroxyalkenals. Against this background, no changes in total superoxide dismutase activity in the organs of seedlings were revealed, and the increased content of low-molecular-weight antioxidants was observed in the roots under 1 μM and in the needles under 5 μM CuSO4 exposures. PMID:27225009

  4. Ozone fumigation under dark/light conditions of Norway Spruce (Picea Abies) and Scots Pine (Pinus Sylvestris)

    NASA Astrophysics Data System (ADS)

    Canaval, Eva; Jud, Werner; Hansel, Armin

    2015-04-01

    Norway Spruce (Picea abies) and Scots Pine (Pinus sylvestris) represent dominating tree species in the northern hemisphere. Thus, the understanding of their ozone sensitivity in the light of the expected increasing ozone levels in the future is of great importance. In our experiments we investigated the emissions of volatile organic compounds (VOCs) of 3-4 year old Norway Spruce and Scots Pine seedlings under ozone fumigation (50-150 ppbv) and dark/light conditions. For the experiments the plants were placed in a setup with inert materials including a glass cuvette equipped with a turbulent air inlet and sensors for monitoring a large range of meteorological parameters. Typical conditions were 20-25°C and a relative humidity of 70-90 % for both plant species. A fast gas exchange rate was used to minimize reactions of ozone in the gas phase. A Switchable-Reagent-Ion-Time-of-Flight-MS (SRI-ToF-MS) was used to analyze the VOCs at the cuvette outlet in real-time during changing ozone and light levels. The use of H3O+ and NO+ as reagent ions allows the separation of certain isomers (e.g. aldehydes and ketones) due to different reaction pathways depending on the functional groups of the molecules. Within the Picea abies experiments the ozone loss, defined as the difference of the ozone concentration between cuvette inlet and outlet, remained nearly constant at the transition from dark to light. This indicates that a major part of the supplied ozone is depleted non-stomatally. In contrast the ozone loss increased by 50 % at the transition from dark to light conditions within Pinus sylvestris experiments. In this case the stomata represent the dominant loss channel. Since maximally 0.1% of the ozone loss could be explained by gas phase reactions with monoterpenes and sesquiterpenes, we suggest that ozone reactions on the surface of Picea abies represent the major sink in this case and lead to an light-independent ozone loss. This is supported by the fact that we detected

  5. Response of soil organic layer characteristics to different amounts of logging residue in a Scots pine thinning stand

    NASA Astrophysics Data System (ADS)

    Smolander, Aino; Kitunen, Veikko; Tamminen, Pekka; Kukkola, Mikko

    2010-05-01

    Since there is an increasing demand for production of bioenergy, forest management using logging residue from both clear-cutting and thinning stands is becoming more common. Therefore there is a need of information how this whole-tree harvest, as compared to the traditional stem-only harvest, changes forest soil characteristics in long-term. The aim of this study was to investigate the effects of logging residue removal on soil microbial processes related to C and N cycling and on two major groups of plant secondary compounds, phenolic compounds and terpenes. These two groups of compounds were of interest since logging residue contains the highest proportion of most of these compounds. In addition, certain phenolic compounds and terpenes have been shown to regulate N transformations in forests soils. The study site was a young Scots pine stand in central Finland. It was thinned and four different amounts of logging residue, consisting of needles and tree branches, were distributed around a tree: 0, 40, 80 and 120 kg of fresh logging residue on a circle (diameter 2.5 m) around a tree. Samples were taken from the organic layer (F+H) four years after the treatment. Two highest amounts of logging residue increased both C and net N mineralization and glucose-induced respiration, but the amount of logging residue did not affect microbial biomass C or N. There were not any large differences between the treatments in the concentrations of mono, sesqui-, di- or triterpenes, although some terpenes showed an increase with the highest amount of residues. Amount of logging residue did not clearly affect the concentrations of volatile monoterpenes in soil atmosphere.

  6. Biotic and abiotic factors affecting stemflow variability in downy oak and Scots pine stands in Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Cayuela, Carles; Garcia-Estringana, Pablo; Latron, Jérôme; Llorens, Pilar

    2015-04-01

    Although stemflow is only a small portion of rainfall, it may represent an important local input of water and nutrients at the plant stem. Previous studies have shown that stemflow has a significant influence on hydrological and biogeochemical processes. Stemflow volume is affected by many biotic factors as species, age, branch or bark characteristics. Moreover, the seasonality of the rainfall regime in Mediterranean areas, which includes both frontal rainfall events and short convective storms, can add complexity to the rainfall-stemflow relationship. This work investigates stemflow dynamics and the influence of biotic and abiotic factors on stemflow rates in two Mediterranean stands during the leafed period - from May to October. The monitored stands are a Downy oak forest (Quercus pubescens) and a Scots pine forest (Pinus sylvestris), both located in the Vallcebre research catchments (NE Spain, 42° 12'N, 1° 49'E). The monitoring design of each plot consists of 7 stemflow rings connected to tipping-buckets, bulk rainfall measured in a nearby clearing and meteorological conditions above the canopies. All data were recorded at 5 min interval. Biometric characteristics of the measured trees were also measured. The analysis of 39 rainfall events (65% smaller than 10 mm) shows that stemflow accounted for less than 1% of the bulk rainfall in both stands. Results also show that, on average, the rainfall amount required for the start of the stemflow and the time delay between the beginning of the precipitation and the start of stemflow are higher in the Downy oak forest. As suggested by stemflow funneling ratios, these differences might be linked to the canopy structure and bark water storage capacity of the trees, indicating that during low magnitude events, oaks have more difficulty to reach storage capacity. The role of other biotic and abiotic parameters on stemflow variability in both stands is still under investigation.

  7. Regional scale gradients of climate and nitrogen deposition drive variation in ectomycorrhizal fungal communities associated with native Scots pine.

    PubMed

    Jarvis, S; Woodward, S; Alexander, I J; Taylor, A F S

    2013-06-01

    Ectomycorrhizal fungi commonly associate with the roots of forest trees where they enhance nutrient and water uptake, promote seedling establishment and have an important role in forest nutrient cycling. Predicting the response of ectomycorrhizal fungi to environmental change is an important step to maintaining forest productivity in the future. These predictions are currently limited by an incomplete understanding of the relative significance of environmental drivers in determining the community composition of ectomycorrhizal (ECM) fungi at large spatial scales. To identify patterns of community composition in ECM fungi along regional scale gradients of climate and nitrogen deposition in Scotland, fungal communities were analysed from 15 seminatural Scots pine (Pinus sylvestris L.) forests. Fungal taxa were identified by sequencing of the ITS rDNA region using fungal-specific primers. Nonmetric multidimensional scaling was used to assess the significance of 16 climatic, pollutant and edaphic variables on community composition. Vector fitting showed that there was a strong influence of rainfall and soil moisture on community composition at the species level, and a smaller impact of temperature on the abundance of ectomycorrhizal exploration types. Nitrogen deposition was also found to be important in determining community composition, but only when the forest experiencing the highest deposition (9.8 kg N ha(-1)  yr(-1) ) was included in the analysis. This finding supports previously published critical load estimates for ectomycorrhizal fungi of 5-10 kg N ha(-1)  yr(-1) . This work demonstrates that both climate and nitrogen deposition can drive gradients of fungal community composition at a regional scale. PMID:23505218

  8. Impacts of soil moisture on de novo monoterpene emissions from European beech, Holm oak, Scots pine, and Norway spruce

    NASA Astrophysics Data System (ADS)

    Wu, C.; Pullinen, I.; Andres, S.; Carriero, G.; Fares, S.; Goldbach, H.; Hacker, L.; Kasal, T.; Kiendler-Scharr, A.; Kleist, E.; Paoletti, E.; Wahner, A.; Wildt, J.; Mentel, Th. F.

    2015-01-01

    Impacts of soil moisture on de novo monoterpene (MT) emissions from Holm oak, European beech, Scots pine, and Norway spruce were studied in laboratory experiments. The volumetric water content of the soil, Θ, was used as the reference quantity to parameterize the dependency of MT emissions on soil moisture and to characterize the severity of the drought. When Θ dropped from 0.4 m3 × m-3 to ~0.2 m3 × m-3 slight increases of de novo MT emissions were observed but with further progressing drought the emissions decreased to almost zero. In most cases the increases of MT emissions observed under conditions of mild drought were explainable by increases of leaf temperature due to lowered transpirational cooling. When Θ fell below certain thresholds, MT emissions decreased simultaneously with Θ and the relationship between Θ and MT emissions was approximately linear. The thresholds of Θ (0.044-0.19 m3 × m-3) were determined, as well as other parameters required to describe the soil moisture dependence of de novo MT emissions for application in the Model of Emissions of Gases and Aerosols from Nature, MEGAN. A factorial approach was found appropriate to describe the impacts of Θ, temperature, and light. Temperature and Θ influenced the emissions largely independently from each other, and, in a similar manner, light intensity and Θ acted independently on de novo MT emissions. The use of Θ as the reference quantity in a factorial approach was tenable in predicting constitutive de novo MT emissions when Θ changed on a time scale of days. Empirical parameterization with Θ as a reference was only unsuccessful when soil moisture changed rapidly

  9. Impacts of soil moisture on de-novo monoterpene emissions from European beech, Holm oak, Scots pine, and Norway spruce

    NASA Astrophysics Data System (ADS)

    Wu, C.; Pullinen, I.; Andres, S.; Carriero, G.; Fares, S.; Goldbach, H.; Hacker, L.; Kasal, T.; Kiendler-Scharr, A.; Kleist, E.; Paoletti, E.; Wahner, A.; Wildt, J.; Mentel, T. F.

    2014-09-01

    Impacts of soil moisture on de-novo monoterpene (MT) emissions from Holm oak, European beech, Scots pine, and Norway spruce were studied in laboratory experiments. The volumetric water content of the soil, Θ, was used as reference quantity to parameterize the dependency of MT emissions on soil moisture and to characterize the severity of the drought. When Θ dropped from 0.4 m3 m-3 to ~ 0.2 m3 m-3 slight increases of de-novo MT emissions were observed but with further progressing drought the emissions decreased to almost zero. The increases of MT emissions observed under conditions of mild drought were explainable by increases of leaf temperature due to lowered transpirational cooling. When Θ fell below certain thresholds, MT emissions decreased simultaneously with Θ and the relationship between Θ and MT emissions was approximately linear. The thresholds of Θ (0.044-0.19 m3 m-3) were determined as well other parameters required to describe the soil moisture dependence of de-novo MT emissions for application in the Model of Emissions of Gases and Aerosols from Nature, MEGAN. A factorial approach was found appropriate to describe the impacts of Θ, temperature, and light. Temperature and Θ influenced the emissions largely independent from each other, and, in a similar manner, light intensity and Θ acted independently on de-novo MT emissions. The use of Θ as reference quantity in a factorial approach was tenable in predicting constitutive de-novo MT emissions when Θ changed on a time scale of days. Only when soil moisture changed suddenly empirical parameterization with Θ as a reference was unsuccessful.

  10. Ectomycorrhizal fungi and exogenous auxins influence root and mycorrhiza formation of Scots pine hypocotyl cuttings in vitro.

    PubMed

    Niemi, K; Vuorinen, T; Ernstsen, A; Häggman, H

    2002-12-01

    We studied the ability of the ectomycorrhizal (ECM) fungi, Pisolithus tinctorius (Pers.) Coker and Couch and Paxillus involutus (Batsch) Fr. (Strain H), to produce indole-3-acetic acid (IAA) and to affect the formation and growth of roots on Scots pine (Pinus sylvestris L.) hypocotyl cuttings in vitro. Effects of indole-3-butyric acid (IBA) and the auxin transport inhibitor, 2,3,5-triiodobenzoic acid (TIBA), on rooting and the cutting-fungus interaction were also studied. Both fungi produced IAA in the absence of exogenous tryptophan, but the mycelium and culture filtrate of Pisolithus tinctorius contained higher concentrations of free and conjugated IAA than the mycelium and culture filtrate of Paxillus involutus. Inoculation with either fungus or short-term application of culture filtrate of either fungus to the base of hypocotyl cuttings enhanced root formation. Inoculation with either fungus was even more effective in enhancing root formation than treatment of the hypocotyl bases with IBA. Fungal IAA production was not directly correlated with root formation, because rooting was enhanced more by Paxillus involutus than by Pisolithus tinctorius. This suggests that, in addition to IAA, other fungal components play an important role in root formation. Treatment with 5 microM TIBA increased the rooting percentage of non-inoculated cuttings, as well as of cuttings inoculated with Pisolithus tinctorius, perhaps as a result of accumulation of IAA at the cutting base. However, the marked reduction in growth of Pisolithus tinctorius in the presence of TIBA suggests that the effects of TIBA on rooting are complicated and not solely related to IAA metabolism. The high IAA-producer, Pisolithus tinctorius, formed mycorrhizas, and the IBA treatment increased mycorrhizal frequency in this species, whereas TIBA decreased it. Paxillus involutus did not form mycorrhizas, indicating that a low concentration of IAA together with other fungal components were sufficient to stimulate

  11. Processes, dynamics and modelling of radiocaesium cycling in a chronosequence of Chernobyl-contaminated Scots pine (Pinus sylvestris L.) plantations.

    PubMed

    Goor, François; Thiry, Yves

    2004-06-01

    In a large forested area affected by the Chernobyl radioactive fallout, especially in CIS, the lasting recycling of radiocaesium (137Cs) by the trees is a source of long-term contamination of woody products. The quantitative description of the 137Cs dynamics in contaminated forest is a prerequisite to predictive modelling and further management of such territories. Three even-aged mono-specific Scots pine stands (17, 37 and 57 years old) were selected in a contaminated woodland in southeastern Belarus to constitute an adequate chronosequence. We determined the potassium and radiocaesium annual fluxes involved in the biological cycling in each stand using a well-documented calculation methodology. Qualitatively, 137Cs was shown to be rapidly recycled in trees through the same pathways as K and to redistribute similarly between the tree components. Compared to K, a higher fraction of 137Cs, corresponding to about the half of the annual uptake, is immobilised in perennial organs. With tree development, trunk wood and bark become prevailing sinks for 137Cs since they represent an increasing pool of biomass. In the pine chronosequence, the current root absorption, respectively, mobilizes 0.53, 0.32 and 0.31% year(-1) of the total 137Cs pool in soil. Variations in the 137Cs uptake do not reflect differences in the 137Cs balance between stands. In the two older stands, 51 and 71% of the current tree contamination are related to earlier accumulation subsequent to the initial fallout interception and recycling. The soil is the dominant source of long-term tree contamination. A simple modelling based on the measured 137Cs fluxes indicates that, for young stands, radioactive decay-corrected contamination would stabilize after reaching a maximum of 25 years after the 137Cs deposition. Stemwood presents a maximum of 15 years after the deposition and decrease afterwards mainly through radioactive decay. In the older stands, the decontamination is constant without local maximum

  12. Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and metals in scots pine (Pinus sylvestris) needles from Eastern and Northern Europe: Spatiotemporal patterns, and potential sources.

    PubMed

    Holt, Eva; Kočan, Anton; Klánová, Jana; Assefa, Anteneh; Wiberg, Karin

    2016-08-01

    Pine needles were sampled to determine levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and metals in Scots pine (Pinus sylvestris) needles at industrial, urban and background sites in Sweden (SW), Czech Republic (CZ) and Slovakia (SK). Spatial and temporal patterns of PCDD/Fs in pine needles were investigated and principal component analysis (PCA) used to determine spatial patterns, potential sources and transport of PCDD/Fs. Levels of PCDD/Fs in pine needles were generally greatest near to industrial sites (Ʃ2,3,7,8-PCDD/Fs (lower bound (LB)): 6 ng kg(-1) - 190 ng kg(-1)) compared to urban and background sites (Ʃ2,3,7,8-PCDD/Fs (LB): 0.90 ng kg(-1) - 20 ng kg(-1)). Using metal contamination in pine needles helped to detect spatial patterns and separate local thermal sources of PCDD/Fs. PMID:27160632

  13. AmeriFlux CA-Qcu Quebec - Eastern Boreal, Black Spruce/Jack Pine Cutover

    SciTech Connect

    Margolis, Hank A.

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site CA-Qcu Quebec - Eastern Boreal, Black Spruce/Jack Pine Cutover. Site Description - The ground is gently rolling with a weak slope (<5%). In mesic areas (designated as well to moderately well drained areas, according to the Canadian System of Soil Classification (Agriculture Canada Expert Committee on Soil Survey, 1983)), the soil is a ferro-humic to humic podzol covered by an organic layer having an average depth of 26 cm (Fig. 1). In humid areas, the soil is organic (imperfectly to poorly drained) with an average organic layer of 125 cm. Mesic areas accounted for approximately 75% of the total surface area of the footprint and humid areas accounted for 25%. Full-time continuous measurements eneded in 2011. Intermittent measurements are on-going as resources permit.

  14. Fire Impact on Surface Fuels and Carbon Emissions in Scots pine Logged Sites of Siberia

    NASA Astrophysics Data System (ADS)

    Ivanova, G. A.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Ivanov, V. A.; Zhila, S. V.; Conard, S. G.

    2012-04-01

    Forest fire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares. Logged sites are characterized by higher fire hazard than forest sites due great amounts of logging slash, which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population. Both legal and illegal logging are also increasing rapidly in many forest areas of Siberia. Fire effects on forest overstory, subcanopy woody layer, and ground vegetation biomass were estimated on logged vs. unlogged sites in the Central Siberia region in 2009-2012 as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). Dead down woody fuels are significantly less at unburned/logged area of dry southern regions compared to more humid northern regions. Fuel consumption was typically less in spring fires than during summer fires. Fire-caused carbon emissions on logged sites appeared to be twice that on unlogged sites. Soil respiration is less at logged areas compared to undisturbed forest. After fire soil respiration decreases both at logged and unlogged areas. arbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

  15. Influence of Climatic Type of Year on Beech and Scots Pine Eustress

    NASA Astrophysics Data System (ADS)

    Lyubenova, Mariyana; Chikalanov, Alexandre; van Bodegom, Peter; Kattge, Jens; Popova, Silvia; Zlateva, Plamena

    2016-04-01

    The present study deals with the relationships of climate types and the periods with low radial stem growth of black pine and beech locations in Europe. The identification of climatic types (CT) and eustress caused CT, their relative participation in the period of 1901-2009 by locations, the manifestation of main adverse type, led periodically to reduction of tree ring width, as well as the comparison of obtained types by precipitations and the SPI classes were the subjects of investigation. The analyses demonstrated that despite the local differences, the stress impact of dry and wet years, especially if they are accompanied by the cold or hot regimes, is well expressed. The successive changes of climate types at least two years before the eustress year are also relevant. The application of climatic types to study the relationship with trees eustress is more applicable when there are no large deviations in temperatures or precipitations by years and locations. The demonstrated holistic analyses are applicable for the forest areas monitoring and management. Key words Pinus sylvestris L., Fagus sylvatica L., climatic type, SPI, eustress, SPPAM application, SPI

  16. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds in Scots pine ( Pinus sylvestris) wood . Part II. Hydrophilic compounds

    NASA Astrophysics Data System (ADS)

    Nuopponen, M.; Willför, S.; Jääskeläinen, A.-S.; Vuorinen, T.

    2004-11-01

    Hydrophilic extracts of Scots pine ( Pinus sylvestris) heartwood and sapwood and a solid Scots pine knotwood sample were studied by UV resonance Raman spectroscopy (UVRRS). In addition, UVRR spectra of two hydrophilic model compounds (pinosylvin and chrysin) were analysed. UV Raman spectra were collected using 244 and 257 nm excitation wavelengths. The chemical composition of the acetone:water (95:5 v/v) extracts were also determined by gas chromatography. The aromatic and oleophilic structures of pinosylvin and chrysin showed three intense resonance enhanced bands in the spectral region of 1649-1548 cm -1. Pinosylvin showed also a relatively intense band in the aromatic substitution region at 996 cm -1. The spectra of the heartwood acetone:water extract showed many bands typical of pinosylvin. In addition, the extract included bands distinctive for resin and fatty acids. The sapwood acetone:water extract showed bands due to oleophilic structures at 1655-1650 cm -1. The extract probably also contained oligomeric lignans because the UVRR spectra were in parts similar to that of guaiacyl lignin. The characteristic band of pinosylvin (996 cm -1) was detected in the UVRR spectrum of the resin rich knotwood. In addition, several other bands typical for wood resin were observed, which indicated that the wood resin in the knotwood was resonance enhanced even more than lignin.

  17. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds in Scots pine (Pinus sylvestris) wood. Part II. Hydrophilic compounds.

    PubMed

    Nuopponen, M; Willför, S; Jääskeläinen, A-S; Vuorinen, T

    2004-11-01

    Hydrophilic extracts of Scots pine (Pinus sylvestris) heartwood and sapwood and a solid Scots pine knotwood sample were studied by UV resonance Raman spectroscopy (UVRRS). In addition, UVRR spectra of two hydrophilic model compounds (pinosylvin and chrysin) were analysed. UV Raman spectra were collected using 244 and 257 nm excitation wavelengths. The chemical composition of the acetone:water (95:5 v/v) extracts were also determined by gas chromatography. The aromatic and oleophilic structures of pinosylvin and chrysin showed three intense resonance enhanced bands in the spectral region of 1649-1548 cm(-1). Pinosylvin showed also a relatively intense band in the aromatic substitution region at 996 cm(-1). The spectra of the heartwood acetone:water extract showed many bands typical of pinosylvin. In addition, the extract included bands distinctive for resin and fatty acids. The sapwood acetone:water extract showed bands due to oleophilic structures at 1655-1650 cm(-1). The extract probably also contained oligomeric lignans because the UVRR spectra were in parts similar to that of guaiacyl lignin. The characteristic band of pinosylvin (996 cm(-1)) was detected in the UVRR spectrum of the resin rich knotwood. In addition, several other bands typical for wood resin were observed, which indicated that the wood resin in the knotwood was resonance enhanced even more than lignin. PMID:15477131

  18. Evidence that the negative relationship between seed mass and relative growth rate is not physiological but linked to species identity: a within-family analysis of Scots pine.

    PubMed

    Castro, Jorge; Reich, Peter B; Sánchez-Miranda, Angela; Guerrero, Juan D

    2008-07-01

    Seed mass and relative growth rate (RGR) are important determinants of early seedling growth, and hence seedling establishment. Although a positive interspecific relationship between seed mass and seedling dry mass is well established, much less is known about the relationships among seed mass, seedling mass and RGR within species. We examined relationships among seed mass, seedling mass and RGR within and among maternal plant lines of Scots pine (Pinus sylvestris L.). To assess the effects of seed mass and maternal origin on RGR, individual seeds from two seed crops (years 2004 and 2005) of ten maternal plants growing under nursery conditions were weighed and then germinated. Seed mass was strongly determined by maternal plant, and seedling mass was largely determined by seed mass, with a positive correlation between these variables both across and within maternal plants. In contrast, RGR was weakly related to seed mass, with no consistent pattern in the sign of the relationship. It is well known that species differ in RGR and that RGR is related to seed mass across species. Lack of consistent evidence for this relationship within maternal lines, and for Scots pine overall, suggests that the relationship is not directly causal, but reflects consistent evolutionary covariation in these two physiologically independent traits. PMID:18450572

  19. Effects of male fecundity, interindividual distance and anisotropic pollen dispersal on mating success in a Scots pine (Pinus sylvestris) seed orchard.

    PubMed

    Torimaru, T; Wennström, U; Lindgren, D; Wang, X-R

    2012-03-01

    Quantifying the effect of pollen dispersal and flowering traits on mating success is essential for understanding evolutionary responses to changing environments and establishing strategies for forest tree breeding. This study examined, quantitatively, the effects of male fecundity, interindividual distance and anisotropic pollen dispersal on the mating success of Scots pine (Pinus sylvestris), utilizing a well-mapped Scots pine seed orchard. Paternity analysis of 1021 seeds sampled from 87 trees representing 28 clones showed that 53% of the seeds had at least one potential pollen parent within the orchard. Pronounced variation in paternal contribution was observed among clones. Variations in pollen production explained up to 78% of the variation in mating success, which was 11.2 times greater for clones producing the largest amount of pollen than for clones producing the least pollen. Mating success also varied with intertree distance and direction, which explained up to 28% of the variance. Fertilization between neighboring trees 2.3 m apart was 2.4 times more frequent than between trees 4.6 m apart, and up to 12.4 times higher for trees downwind of the presumed prevailing wind direction than for upwind trees. The effective number of pollen donors recorded in the seed orchard (12.2) was smaller than the theoretical expectation (19.7). Based on the empirical observations, a mating model that best describes the gene dispersal pattern in clonal seed orchards was constructed. PMID:21897440

  20. Has Scots pine (Pinus sylvestris) co-evolved with Dothistroma septosporum in Scotland? Evidence for spatial heterogeneity in the susceptibility of native provenances.

    PubMed

    Perry, Annika; Brown, Anna V; Cavers, Stephen; Cottrell, Joan E; Ennos, Richard A

    2016-09-01

    Spatial heterogeneity in pathogen pressure leads to genetic variation in, and evolution of, disease-related traits among host populations. In contrast, hosts are expected to be highly susceptible to exotic pathogens as there has been no evolution of defence responses. Host response to pathogens can therefore be an indicator of a novel or endemic pathosystem. Currently, the most significant threat to native British Scots pine (Pinus sylvestris) forests is Dothistroma needle blight (DNB) caused by the foliar pathogen Dothistroma septosporum which is presumed to be exotic. A progeny-provenance trial of 6-year-old Scots pine, comprising eight native provenances each with four families in six blocks, was translocated in April 2013 to a clear-fell site in Galloway adjacent to a DNB-infected forest. Susceptibility to D. septosporum, measured as DNB severity (estimated percentage nongreen current-year needles), was assessed visually over 2 years (2013-2014 and 2014-2015; two assessments per year). There were highly significant differences in susceptibility among provenances but not among families for each annual assessment. Provenance mean susceptibility to D. septosporum was negatively and significantly associated with water-related variables at site of origin, potentially due to the evolution of low susceptibility in the host in response to high historical pathogen pressure. PMID:27606006

  1. The HartX-synthesis: An experimental approach to water and carbon exchange of a Scots pine plantation

    NASA Astrophysics Data System (ADS)

    Bernhofer, Ch.; Gay, L. W.; Granier, A.; Joss, U.; Kessler, A.; Köstner, B.; Siegwolf, R.; Tenhunen, J. D.; Vogt, R.

    1996-03-01

    In May 1992 during the interdisciplinary measurement campaign HartX (Hartheim eXperiment), several independent estimates of stand water vapor flux were compared at a 12-m high Scots pine ( Pinus silvestris) plantation on a flat fluvial terrace of the Rhine close to Freiburg, Germany. Weather during the HartX period was characterized by ten consecutive clear days with exceptionally high input of available energy for this time of year and with a slowly shifting diurnal pattern in atmospheric variables like vapor pressure deficit. Methods utilized to quantify components of stand water flux included porometry measurements on understory graminoid leaves and on pine needles and three different techniques for determining individual tree xylem sap flow. Micrometeorological methods included eddy covariance and eddy covariance energy balance techniques with six independent systems on two towers separated by 40 m. Additionally, Bowen ratio energy balance estimates of water flux were conducted and measurements of the gradients in water vapor, CO2, and trace gases within and above the stand were carried out with an additional, portable 30 m high telescoping mast. Biologically-based estimates of overstory transpiration were obtained by up-scaling tree sap flow rates to stand level via cumulative sapwood area. Tree transpiration contributed between 2.2 and 2.6 mm/day to ET for a tree leaf area index (LAI) of 2.8. The pine stand had an understory dominated by sedge and grass species with overall average LAI of 1.5. Mechanistic canopy gas exchange models that quantify both water vapor and CO2 exchange were applied to both understory and tree needle ecosystem compartments. Thus, the transpiration by graminoid species was estimated at approximately 20% of total stand ET. The modelled estimates for understory contribution to stand water flux compared well with micrometeorologically-based determinations. Maximum carbon gain was estimated from the canopy models at approximately 425 mmol

  2. The effect of internal and external nitrogen on needle litter decomposition in a Dutch scots pine forest.

    NASA Astrophysics Data System (ADS)

    Tietema, A.; Wessels, W.

    2009-04-01

    A litterbag experiment was carried out in 2001 in a Scots pine (Pinus sylvestris L.) stand in the southern part of The Netherlands, near Ysselsteyn. The region is characterized by high atmoshpheric nitrogen (N) deposition of about 58 kg N ha-1 yr-1. In the winter of 1988-1989 the high N deposition was experimentally decreased to pre-industrial N deposition rates by means of a transparent roof installed about 2-3 m above the forest floor. Decomposition of needles was studied under the roof in the low N deposition plot (about 6 kg N ha-1 yr-1) and in the ambient plot outside the roof, receiving natural N deposition. Needles were separately sampled from the low and the ambient deposition plot and incubated separately in both plots. This made it possible to examine the effect of internal N (origin of needles) and external N (deposition during incubation) in the different stages of decomposition. The original litter revealed significant negative correlations between N content and lignin-to-N ratio, Mn and Ca concentration were found. The lignin content was negatively correlated to Ca and Mn concentration. The N content of the litter increased from 1.3 % to the maximum of 2.0 % during the first 12-18 months. A C/N ratio of 26 was reached within 12 months. During the first three months 30 % of the mass loss occurred in all litter types. After 12 months only 60 % of the original mass remained. Decomposition for the first 18 months mass was lower for both litter types incubated in the low deposition plot. Then the decomposition rate for the low N needles in the high N plot flattened off. No difference in decomposition rate of the litter originating from low or high deposition plots was found during the whole incubation period. This would indicate that external deposition N is more important than internal tissue N in determining the decomposition rate and that low N deposition retarded decomposition in this initial stage of the decomposition process.

  3. The Intracellular Scots Pine Shoot Symbiont Methylobacterium extorquens DSM13060 Aggregates around the Host Nucleus and Encodes Eukaryote-Like Proteins

    PubMed Central

    Koskimäki, Janne J.; Pirttilä, Anna Maria; Ihantola, Emmi-Leena; Halonen, Outi

    2015-01-01

    ABSTRACT Endophytes are microbes that inhabit plant tissues without any apparent signs of infection, often fundamentally altering plant phenotypes. While endophytes are typically studied in plant roots, where they colonize the apoplast or dead cells, Methylobacterium extorquens strain DSM13060 is a facultatively intracellular symbiont of the meristematic cells of Scots pine (Pinus sylvestris L.) shoot tips. The bacterium promotes host growth and development without the production of known plant growth-stimulating factors. Our objective was to examine intracellular colonization by M. extorquens DSM13060 of Scots pine and sequence its genome to identify novel molecular mechanisms potentially involved in intracellular colonization and plant growth promotion. Reporter construct analysis of known growth promotion genes demonstrated that these were only weakly active inside the plant or not expressed at all. We found that bacterial cells accumulate near the nucleus in intact, living pine cells, pointing to host nuclear processes as the target of the symbiont’s activity. Genome analysis identified a set of eukaryote-like functions that are common as effectors in intracellular bacterial pathogens, supporting the notion of intracellular bacterial activity. These include ankyrin repeats, transcription factors, and host-defense silencing functions and may be secreted by a recently imported type IV secretion system. Potential factors involved in host growth include three copies of phospholipase A2, an enzyme that is rare in bacteria but implicated in a range of plant cellular processes, and proteins putatively involved in gibberellin biosynthesis. Our results describe a novel endophytic niche and create a foundation for postgenomic studies of a symbiosis with potential applications in forestry and agriculture. PMID:25805725

  4. Effect of raw humus under two adult Scots pine stands on ectomycorrhization, nutritional status, nitrogen uptake, phosphorus uptake and growth of Pinus sylvestris seedlings.

    PubMed

    Schulz, Horst; Schäfer, Tina; Storbeck, Veronika; Härtling, Sigrid; Rudloff, Renate; Köck, Margret; Buscot, François

    2012-01-01

    Ectomycorrhiza (EM) formation improves tree growth and nutrient acquisition, particularly that of nitrogen (N). Few studies have coupled the effects of naturally occurring EM morphotypes to the nutrition of host trees. To investigate this, pine seedlings were grown on raw humus substrates collected at two forest sites, R2 and R3. Ectomycorrhiza morphotypes were identified, and their respective N uptake rates from organic (2-(13)C, (15)N-glycine) and inorganic ((15)NH(4)Cl, Na(15)NO(3), (15)NH(4)NO(3), NH(4)(15)NO(3)) sources as well as their phosphate uptake rates were determined. Subsequently, the growth and nutritional status of the seedlings were analyzed. Two dominant EM morphotypes displayed significantly different mycorrhization rates in the two substrates. Rhizopogon luteolus Fr. (RL) was dominant in R2 and Suillus bovinus (Pers.) Kuntze (SB) was dominant in R3. (15)N uptake of RL EM was at all times higher than that of SB EM. Phosphate uptake rates by the EM morphotypes did not differ significantly. The number of RL EM correlated negatively and the number of SB EM correlated positively with pine growth rate. Increased arginine concentrations and critical P/N ratios in needles indicated nutrient imbalances of pine seedlings from humus R2, predominantly mycorrhizal with RL. We conclude that different N supply in raw humus under Scots pine stands can induce shifts in the EM frequency of pine seedlings, and this may lead to EM formation by fungal strains with different ability to support tree growth. PMID:22184278

  5. The role of defoliation and root rot pathogen infection in driving the mode of drought-related physiological decline in Scots pine (Pinus sylvestris L.).

    PubMed

    Aguadé, D; Poyatos, R; Gómez, M; Oliva, J; Martínez-Vilalta, J

    2015-03-01

    Drought-related tree die-off episodes have been observed in all vegetated continents. Despite much research effort, however, the multiple interactions between carbon starvation, hydraulic failure and biotic agents in driving tree mortality under field conditions are still not well understood. We analysed the seasonal variability of non-structural carbohydrates (NSCs) in four organs (leaves, branches, trunk and roots), the vulnerability to embolism in roots and branches, native embolism (percentage loss of hydraulic conductivity (PLC)) in branches and the presence of root rot pathogens in defoliated and non-defoliated individuals in a declining Scots pine (Pinus sylvestris L.) population in the NE Iberian Peninsula in 2012, which included a particularly dry and warm summer. No differences were observed between defoliated and non-defoliated pines in hydraulic parameters, except for a higher vulnerability to embolism at pressures below -2 MPa in roots of defoliated pines. No differences were found between defoliation classes in branch PLC. Total NSC (TNSC, soluble sugars plus starch) values decreased during drought, particularly in leaves. Defoliation reduced TNSC levels across tree organs, especially just before (June) and during (August) drought. Root rot infection by the fungal pathogen Onnia P. Karst spp. was detected but it did not appear to be associated to tree defoliation. However, Onnia infection was associated with reduced leaf-specific hydraulic conductivity and sapwood depth, and thus contributed to hydraulic impairment, especially in defoliated pines. Infection was also associated with virtually depleted root starch reserves during and after drought in defoliated pines. Moreover, defoliated and infected trees tended to show lower basal area increment. Overall, our results show the intertwined nature of physiological mechanisms leading to drought-induced mortality and the inherent difficulty of isolating their contribution under field conditions. PMID

  6. Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands.

    PubMed

    Boxman, Andries W; Peters, Roy C J H; Roelofs, Jan G M

    2008-12-01

    In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (-40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO3(-) and SO4(2-) have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem. PMID:18457906

  7. Assessing environmental and physiological controls over water relations in a Scots pine (Pinus sylvestris L.) stand through analyses of stable isotope composition of water and organic matter.

    PubMed

    Brandes, Elke; Wenninger, Jochen; Koeniger, Paul; Schindler, Dirk; Rennenberg, Heinz; Leibundgut, Christian; Mayer, Helmut; Gessler, Arthur

    2007-01-01

    This study investigated the influence of meteorological, pedospheric and physiological factors on the water relations of Scots pine, as characterized by the origin of water taken up, by xylem transport as well as by carbon isotope discrimination (Delta13C) and oxygen isotope enrichment (Delta18O) of newly assimilated organic matter. For more than 1 year, we quantified delta2H and delta18O of potential water sources and xylem water as well as Delta13C and Delta18O in twig and trunk phloem organic matter biweekly, and related these values to continuously measured or modelled meteorological parameters, soil water content, stand transpiration (ST) and canopy stomatal conductance (G(s)). During the growing season, delta18O and delta2H of xylem water were generally in a range comparable to soil water from a depth of 2-20 cm. Long residence time of water in the tracheids uncoupled the isotopic signals of xylem and soil water in winter. Delta18O but not Delta13C in phloem organic matter was directly indicative of recent environmental conditions during the whole year. Delta18O could be described applying a model that included 18O fractionation associated with water exchange between leaf and atmosphere, and with the production of organic matter as well as the influence of transpiration. Phloem Delta13C was assumed to be concertedly influenced by G(s) and photosynthetically active radiation (PAR) (as a proxy for photosynthetic capacity). We conclude that isotope signatures can be used as effective tools (1) to characterize the seasonal dynamics in source and xylem water, and (2) to assess environmental effects on transpiration and G(s) of Scots pine, thus helping to understand and predict potential impacts of climate change on trees and forest ecosystems. PMID:17177880

  8. Influence of throughfall spatial and temporal patterns on soil moisture variability under Downy oak and Scots pine stands in Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Llorens, Pilar; Garcia-Estringana, Pablo; Cayuela, Carles; Latron, Jérôme; Molina, Antonio; Gallart, Francesc

    2015-04-01

    Temporal and spatial variability of throughfall and stemflow patterns, due to differences in forest structure and seasonality of Mediterranean climate, may lead to significant changes in the volume of water that locally reaches the soil, with a potential effect on groundwater recharge and on hydrological response of forested hillslopes. Two forest stands in Mediterranean climatic conditions were studied to explore the role of vegetation on the temporal and spatial redistribution of rainfall. One is a Downy oak forest (Quercus pubescens) and the other is a Scots pine forest (Pinus sylvestris), both located in the Vallcebre research catchments (NE Spain, 42° 12'N, 1° 49'E). These plots are representative of Mediterranean mountain areas with spontaneous afforestation by Scots pine as a consequence of the abandonment of agricultural terraces, formerly covered by Downy oaks. The monitoring design of each plot consists of 20 automatic rain recorders to measuring throughfall, 7 stemflow rings connected to tipping-buckets and 40 automatic soil moisture probes. All data were recorded each 5 min. Bulk rainfall and meteorological conditions above both forest covers were also recorded, and canopy cover and biometric characteristics of the plots were measured. Results indicate a marked temporal stability of throughfall in both stands, and a lower persistence of spatial patterns in the leafless period than in the leafed one in the oaks stand. Moreover, in the oaks plot the ranks of gauges in the leafed and leafless periods were not significantly correlated, indicating different wet and dry hotspots in each season. The spatial distribution of throughfall varied significantly depending on rainfall volume, with small events having larger variability, whereas large events tended to homogenize the relative differences in point throughfall. Soil water content spatial variability increased with increasing soil water content, but direct dependence of soil water content variability on

  9. Short-term responses of soil chemistry, needle macronutrients and tree growth to clinker dust and fertiliser in a stand of Scots pine.

    PubMed

    Klõšeiko, Jaan; Ots, Katri; Kuznetsova, Tatjana; Pärn, Henn; Mandre, Malle

    2011-10-01

    Waste management of clinker dust by spreading it on forest soil was studied in a 25-year-old Scots pine stand on acidic sandy soil. Clinker dust (0.5 kg m⁻²), fertiliser (N, P, K, Mg, 0.05 kg m⁻²; N 190 kg ha⁻¹) and untreated soil were applied on 120-m² plots in four replicates. The fertiliser was included to confirm the nutrient limitation in the stand. Clinker dust increased the soil pH by 1.2 units relative to the pH of 4.6 in the untreated soil by the second year. Soil K and Mg concentrations were larger in the dust and fertiliser treatments. Nutrient diagnostics indicated that needles of untreated trees were deficient in N and K. Fertiliser treatment indicated that the growth of trees was limited by N, since the fertiliser tended to increase needle K, N, N/P, needle dry mass and diameters of stem and shoots. By an auxiliary dataset, no effects of the dust and fertiliser on possible excess of the micronutrient Mn were observed. Clinker dust increased needle K concentration, but due to the N limitation, there was no increase in the growth of stems, branches, shoots and needles. It was concluded that in plots of 120 m² application of clinker dust at a rate of 0.5 kg m⁻² was safe for the 21-year-old Scots pine stand in this trial on an acid nutrient-poor sandy soil during 4 years after the treatment. PMID:21161587

  10. The radial increment and stemwood element concentrations of Scots pine in the area influenced by the Narva power plants in Northeast Estonia.

    PubMed

    Ots, Katri; Reisner, Vaike

    2007-07-01

    In the northeastern part of Estonia, near the town of Narva, there are two large oil shale fueled power plants, Baltic PP and Estonian PP. On burning oil shale the main atmospheric pollutants are fly ash, sulphur oxides and nitrogen oxides. The radial increment was measured and concentrations of Ca and Cu were estimated in the stemwood of Scots pine (Pinus sylvestris L.) from four sites in the influence area of the Narva power plants. Increment cores were taken also from two sites in an unpolluted area located 112 and 120 km northwest from the Estonian PP. The stands selected for investigation were similar as to their edaphic conditions and forest survey indicators (75- to 80-year-old (Oxalis-) Myrtillus-type pine stands of 0.7-0.8 density and of quality class II). The strongest effect of air pollution on radial increment was observed on the sampling site in the direction of dominating winds at a distance of 22 km to northeast from the Estonian PP. Using the annual rings, the core samples were divided into five-year sections (1945-1949; 1950-1954 etc.). The concentration of Ca increased and that of Cu decreased from the youngest, outermost annual rings towards the centre of the stem. High concentrations of Ca and Cu in stemwood in 1970-1974 may be due to the launching of the Estonian PP in 1969 in addition to the Baltic PP, which has operated since 1959. PMID:17242973

  11. Fluorescence measurements show stronger cold inhibition of photosynthetic light reactions in Scots pine compared to Norway spruce as well as during spring compared to autumn.

    PubMed

    Linkosalo, Tapio; Heikkinen, Juha; Pulkkinen, Pertti; Mäkipää, Raisa

    2014-01-01

    We studied the photosynthetic activity of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst) in relation to air temperature changes from March 2013 to February 2014. We measured the chlorophyll fluorescence of approximately 50 trees of each species growing in southern Finland. Fluorescence was measured 1-3 times per week. We began by measuring shoots present in late winter (i.e., March 2013) before including new shoots once they started to elongate in spring. By July, when the spring shoots had achieved similar fluorescence levels to the older ones, we proceeded to measure the new shoots only. We analyzed the data by fitting a sigmoidal model containing four parameters to link sliding averages of temperature and fluorescence. A parameter defining the temperature range over which predicted fluorescence increased most rapidly was the most informative with in describing temperature dependence of fluorescence. The model generated similar fluorescence patterns for both species, but differences were observed for critical temperature and needle age. Down regulation of the light reaction was stronger in spring than in autumn. Pine showed more conservative control of the photosynthetic light reactions, which were activated later in spring and more readily attenuated in autumn. Under the assumption of a close correlation of fluorescence and photosynthesis, spruce should therefore benefit more than pine from the increased photosynthetic potential during warmer springs, but be more likely to suffer frost damage with a sudden cooling following a warm period. The winter of 2013-2014 was unusually mild and similar to future conditions predicted by global climate models. During the mild winter, the activity of photosynthetic light reactions of both conifers, especially spruce, remained high. Because light levels during winter are too low for photosynthesis, this activity may translate to a net carbon loss due to respiration. PMID:24982664

  12. Fluorescence measurements show stronger cold inhibition of photosynthetic light reactions in Scots pine compared to Norway spruce as well as during spring compared to autumn

    PubMed Central

    Linkosalo, Tapio; Heikkinen, Juha; Pulkkinen, Pertti; Mäkipää, Raisa

    2014-01-01

    We studied the photosynthetic activity of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst) in relation to air temperature changes from March 2013 to February 2014. We measured the chlorophyll fluorescence of approximately 50 trees of each species growing in southern Finland. Fluorescence was measured 1–3 times per week. We began by measuring shoots present in late winter (i.e., March 2013) before including new shoots once they started to elongate in spring. By July, when the spring shoots had achieved similar fluorescence levels to the older ones, we proceeded to measure the new shoots only. We analyzed the data by fitting a sigmoidal model containing four parameters to link sliding averages of temperature and fluorescence. A parameter defining the temperature range over which predicted fluorescence increased most rapidly was the most informative with in describing temperature dependence of fluorescence. The model generated similar fluorescence patterns for both species, but differences were observed for critical temperature and needle age. Down regulation of the light reaction was stronger in spring than in autumn. Pine showed more conservative control of the photosynthetic light reactions, which were activated later in spring and more readily attenuated in autumn. Under the assumption of a close correlation of fluorescence and photosynthesis, spruce should therefore benefit more than pine from the increased photosynthetic potential during warmer springs, but be more likely to suffer frost damage with a sudden cooling following a warm period. The winter of 2013–2014 was unusually mild and similar to future conditions predicted by global climate models. During the mild winter, the activity of photosynthetic light reactions of both conifers, especially spruce, remained high. Because light levels during winter are too low for photosynthesis, this activity may translate to a net carbon loss due to respiration. PMID:24982664

  13. Acetone and monoterpene emissions from the boreal forest in northern Europe

    NASA Astrophysics Data System (ADS)

    Janson, Robert; de Serves, Claes

    Acetone is a ubiquitous component of the atmosphere which, by its photolysis, can play an important role in photochemical reactions in the free troposphere. This paper investigates the biogenic source of acetone from Scots pine ( Pinus sylvestris) and Norway spruce ( Picea abies) in the Scandinavian boreal zone. Branch emission measurements of acetone, monoterpenes, and isoprene were made with an all-Teflon flow-through branch chamber from five specimens of Scots pine at three sites in Sweden and Finland, and from one specimen of Norway spruce at one site in Sweden. Acetone samples were taken with SepPak™ DNPH cartridges, monoterpenes with Tenax TA, and isoprene with 3 l electropolished canisters. Acetone was found to dominate the carbonyl emission of both Scots pine and Norway spruce, as large as the monoterpene emissions and for Norway spruce, as the isoprene emission. The average standard emission rate (30°C) and average β-coefficient for the temperature correlation for 5 specimens of Scots pine were 870 ng C gdw -1 h -1 (gdw=gram dry weight) and 0.12, respectively. For the monoterpenes the values were 900 ng C gdw -1 h -1 and 0.12, respectively. The standard emission rate (30°C) for acetone from Norway spruce was 265 ng C gdw -1 h -1, but the sparsity of data, along with the unusual weather conditions at the time of the measurements, precludes the establishment of a summertime best estimate emission factor.

  14. Comparisons of xylem sap flow and water vapour flux at the stand level and derivation of canopy conductance for Scots pine

    NASA Astrophysics Data System (ADS)

    Granier, A.; Biron, P.; Köstner, B.; Gay, L. W.; Najjar, G.

    1996-03-01

    Simultaneous measurements of xylem sap flow and water vapour flux over a Scots pine ( Pinus sylvestris) forest (Hartheim, Germany), were carried out during the Hartheim Experiment (HartX), an intensive observation campaign of the international programme REKLIP. Sap flow was measured every 30 min using both radial constant heating (Granier, 1985) and two types of Cermak sap flowmeters installed on 24 trees selected to cover a wide range of the diameter classes of the stand (min 8 cm; max 17.5 cm). Available energy was high during the observation period (5.5 to 6.9 mm.day-1), and daily cumulated sap flow on a ground area basis varied between 2.0 and 2.7 mm day-1 depending on climate conditions. Maximum hourly values of sap flow reached 0.33 mm h-1, i.e., 230 W m-2. Comparisons of sap flow with water vapour flux as measured with two OPEC (One Propeller Eddy Correlation, University of Arizona) systems showed a time lag between the two methods, sap flow lagging about 90 min behind vapour flux. After taking into account this time lag in the sap flow data set, a good agreement was found between both methods: sap flow = 0.745* vapour flux, r 2 = 0.86. The difference between the two estimates was due to understory transpiration. Canopy conductance ( g c ) was calculated from sap flow measurements using the reverse form of Penman-Monteith equation and climatic data measured 4 m above the canopy. Variations of g c were well correlated ( r 2 = 0.85) with global radiation ( R) and vapour pressure deficit ( vpd). The quantitative expression for g c = f ( R, vpd) was very similar to that previously found with maritime pine ( Pinus pinaster) in the forest of Les Landes, South Western France.

  15. Impact of Scots pine (Pinus sylvestris L.) plantings on long term (137)Cs and (90)Sr recycling from a waste burial site in the Chernobyl Red Forest.

    PubMed

    Thiry, Yves; Colle, Claude; Yoschenko, Vasyl; Levchuk, Svjatoslav; Van Hees, May; Hurtevent, Pierre; Kashparov, Valery

    2009-12-01

    Plantings of Scots pine (Pinus sylvestris L.) on a waste burial site in the Chernobyl Red Forest was shown to greatly influence the long term redistribution of radioactivity contained in sub-surfaces trenches. After 15 years of growth, aboveground biomass of the average tree growing on waste trench no.22 had accumulated 1.7 times more (137)Cs than that of trees growing off the trench, and 5.4 times more (90)Sr. At the scale of the trench and according to an average tree density of 3300 trees/ha for the study zone, tree contamination would correspond to 0.024% of the (137)Cs and 2.52% of the (90)Sr contained in the buried waste material. A quantitative description of the radionuclide cycling showed a potential for trees to annually extract up to 0.82% of the (90)Sr pool in the trench and 0.0038% of the (137)Cs. A preferential (90)Sr uptake from the deep soil is envisioned while pine roots would take up (137)Cs mostly from less contaminated shallow soil layers. The current upward flux of (90)Sr through vegetation appeared at least equal to downward loss in waste material leaching as reported by Dewiere et al. (2004, Journal of Environmental Radioactivity 74, 139-150). Using a prospective calculation model, we estimated that maximum (90)Sr cycling can be expected to occur at 40 years post-planting, resulting in 12% of the current (90)Sr content in the trench transferred to surface soils through biomass turnover and 7% stored in tree biomass. These results are preliminary, although based on accurate methodology. A more integrated ecosystem study leading to the coupling between biological and geochemical models of radionuclide cycling within the Red Forest seems opportune. Such a study would help in the adequate management of that new forest and the waste trenches upon which they reside. PMID:19525043

  16. Uptake of ¹³⁷Cs by berries, mushrooms and needles of Scots pine in peatland forests after wood ash application.

    PubMed

    Vetikko, Virve; Rantavaara, Aino; Moilanen, Mikko

    2010-12-01

    Increasing use of wood fuels for energy production in Finland since the 1990s implies that large quantities of the generated ashes will be available for forest fertilization. The aim of this study was to analyse the effect of wood ash application on ¹³⁷Cs activity concentrations in Scots pine (Pinus sylvestris L.) needles and certain berries and mushrooms on drained peatlands. The study was based on field experiments carried out on two mires in Finland in 1997-1998. Two different types of wood ash were applied at dosages of 3500, 3700, 10 500 and 11 100 kg ha⁻¹. Wood ash did not increase ¹³⁷Cs activity concentration in plants in the second growing season following application. On the contrary, a decrease in ¹³⁷Cs activity concentration was seen in the plants of the ecosystem on drained peatlands. This result is of importance, for instance, when recycling of ash is being planned. PMID:20864229

  17. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine ( Pinus sylvestris) wood . Part I: Lipophilic compounds

    NASA Astrophysics Data System (ADS)

    Nuopponen, M.; Willför, S.; Jääskeläinen, A.-S.; Sundberg, A.; Vuorinen, T.

    2004-11-01

    The wood resin in Scots pine ( Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm -1. Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at ˜1650 cm -1 due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin.

  18. A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine (Pinus sylvestris) wood. Part I: lipophilic compounds.

    PubMed

    Nuopponen, M; Willför, S; Jääskeläinen, A-S; Sundberg, A; Vuorinen, T

    2004-11-01

    The wood resin in Scots pine (Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 nm. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm(-1). Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at approximately 1650 cm(-1) due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin. PMID:15477130

  19. Particulate pollutants are capable to 'degrade' epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.).

    PubMed

    Burkhardt, Juergen; Pariyar, Shyam

    2014-01-01

    Air pollution causes the amorphous appearance of epicuticular waxes in conifers, usually called wax 'degradation' or 'erosion', which is often correlated with tree damage symptoms, e.g., winter desiccation. Previous investigations concentrated on wax chemistry, with little success. Here, we address the hypothesis that both 'wax degradation' and decreasing drought tolerance of trees may result from physical factors following the deposition of salt particles onto the needles. Pine seedlings were sprayed with dry aerosols or 50 mM solutions of different salts. The needles underwent humidity changes within an environmental scanning electron microscope, causing salt expansion on the surface and into the epistomatal chambers. The development of amorphous wax appearance by deliquescent salts covering tubular wax fibrils was demonstrated. The minimum epidermal conductance of the sprayed pine seedlings increased. Aerosol deposition potentially 'degrades' waxes and decreases tree drought tolerance. These effects have not been adequately considered thus far in air pollution research. PMID:23791043

  20. Evidences on the Ability of Mycorrhizal Genus Piloderma to Use Organic Nitrogen and Deliver It to Scots Pine

    PubMed Central

    Heinonsalo, Jussi; Sun, Hui; Santalahti, Minna; Bäcklund, Kirsi; Hari, Pertti; Pumpanen, Jukka

    2015-01-01

    Ectomycorrhizal (ECM) symbiosis has been proposed to link plant photosynthesis and soil organic matter (SOM) decomposition through the production of fungal enzymes which promote SOM degradation and nitrogen (N) uptake. However, laboratory and field evidence for the existence of these processes are rare. Piloderma sp., a common ECM genus in boreal forest soil, was chosen as model mycorrhiza for this study. The abundance of Piloderma sp. was studied in root tips and soil over one growing season and in winter. Protease production was measured from ectomycorrhiza and soil solution in the field and pure fungal cultures. We also tested the effect of Piloderma olivaceum on host plant organic N nutrition in the laboratory. The results showed that Piloderma sp. was highly abundant in the field and produced extracellular proteases, which correlated positively with the gross primary production, temperature and soil respiration. In the laboratory, Piloderma olivaceum could improve the ability of Pinus sylvestris L. to utilize N from extragenous proteins. We suggest that ECM fungi, although potentially retaining N in their hyphae, are important in forest C and N cycling due to their ability to access proteinaeous N. As Piloderma sp. abundance appeared to be seasonally highly variable, recycling of fungal-bound N after hyphal death may therefore be of primary importance for the N cycling in boreal ecosystems. PMID:26132469

  1. Evidences on the Ability of Mycorrhizal Genus Piloderma to Use Organic Nitrogen and Deliver It to Scots Pine.

    PubMed

    Heinonsalo, Jussi; Sun, Hui; Santalahti, Minna; Bäcklund, Kirsi; Hari, Pertti; Pumpanen, Jukka

    2015-01-01

    Ectomycorrhizal (ECM) symbiosis has been proposed to link plant photosynthesis and soil organic matter (SOM) decomposition through the production of fungal enzymes which promote SOM degradation and nitrogen (N) uptake. However, laboratory and field evidence for the existence of these processes are rare. Piloderma sp., a common ECM genus in boreal forest soil, was chosen as model mycorrhiza for this study. The abundance of Piloderma sp. was studied in root tips and soil over one growing season and in winter. Protease production was measured from ectomycorrhiza and soil solution in the field and pure fungal cultures. We also tested the effect of Piloderma olivaceum on host plant organic N nutrition in the laboratory. The results showed that Piloderma sp. was highly abundant in the field and produced extracellular proteases, which correlated positively with the gross primary production, temperature and soil respiration. In the laboratory, Piloderma olivaceum could improve the ability of Pinus sylvestris L. to utilize N from extragenous proteins. We suggest that ECM fungi, although potentially retaining N in their hyphae, are important in forest C and N cycling due to their ability to access proteinaeous N. As Piloderma sp. abundance appeared to be seasonally highly variable, recycling of fungal-bound N after hyphal death may therefore be of primary importance for the N cycling in boreal ecosystems. PMID:26132469

  2. Tree rings provide early warning signals of jack pine mortality across a moisture gradient in the southern boreal forest

    NASA Astrophysics Data System (ADS)

    Mamet, S. D.; Chun, K. P.; Metsaranta, J. M.; Barr, A. G.; Johnstone, J. F.

    2015-08-01

    Recent declines in productivity and tree survival have been widely observed in boreal forests. We used early warning signals (EWS) in tree ring data to anticipate premature mortality in jack pine (Pinus banksiana)—an extensive and dominant species occurring across the moisture-limited southern boreal forest in North America. We sampled tree rings from 113 living and 84 dead trees in three soil moisture regimes (subxeric, submesic, subhygric) in central Saskatchewan, Canada. We reconstructed annual increments of tree basal area to investigate (1) whether we could detect EWS related to mortality of individual trees, and (2) how water availability and tree growth history may explain the mortality warning signs. EWS were evident as punctuated changes in growth patterns prior to transition to an alternative state of reduced growth before dying. This transition was likely triggered by a combination of severe drought and insect outbreak. Higher moisture availability associated with a soil moisture gradient did not appear to reduce tree sensitivity to stress-induced mortality. Our results suggest tree rings offer considerable potential for detecting critical transitions in tree growth, which are linked to premature mortality.

  3. Carbon balance of an old hemi-boreal pine forest in Southern Estonia determined by different methods

    NASA Astrophysics Data System (ADS)

    Soosaar, Kaido; Repp, Kalev; Lõhmus, Krista; Uri, Veiko; Rannik, Kaire; Krasnova, Alisa; Ostonen, Ivika; Kukumägi, Mai; Maddison, Martin; Mander, Ülo

    2016-04-01

    The Soontaga Forest Station is located in hemi-boreal 200-years old pine forest (South Estonia; 58o01'N 26o04'E) with a second layer of spruce. The station has the instrumentation to assess the exchange of carbon dioxide (net ecosystem exchange, NEE), soil respiration, tree biomass (above and below ground biomass) and different environmental and meteorological parameters. In this study we quantified carbon balance by analyzing eddy-covariance CO2 flux data (carbon exchange) vs chamber-based measurements (ecosystem respiration) and CO2assimilation (soil and biomass). The annual NEE in this mature coniferous forest was -2.3 t C ha yr‑1, showing a clear diurnal and seasonal trend. During the daytime in summer the forest sequestered CO2, while during the night and late night CO2 emitted from the ecosystem to the atmosphere. Within the growing period, the sequestration of CO2 by plants was greater than soil respiration. Thus, the ecosystem sequestered carbon. Most of the carbon is bound in tree biomass (above and below ground biomass) but as well into soil, while the sequestration in soil increases with stand age. In addition, the biomass of understory, especially belowground litter, is playing essential part in carbon input. A modelling approach of long-term C budget in the Soontaga pine forest is presented.

  4. Impacts of changing climate on the productivity of Norway spruce dominant stands with a mixture of Scots pine and birch in relation to water availability in southern and northern Finland.

    PubMed

    Ge, Zhen-Ming; Kellomäki, Seppo; Peltola, Heli; Zhou, Xiao; Wang, Kai-Yun; Väisänen, Hannu

    2011-03-01

    A process-based ecosystem model was used to assess the impacts of changing climate on net photosynthesis and total stem wood growth in relation to water availability in two unmanaged Norway spruce (Picea abies) dominant stands with a mixture of Scots pine (Pinus sylvestris) and birch (Betula sp.). The mixed stands were grown over a 100-year rotation (2000-99) in southern and northern Finland with initial species shares of 50, 25 and 25% for Norway spruce, Scots pine and birch, respectively. In addition, pure Norway spruce, Scots pine and birch stands were used as a comparison to identify whether species' response is different in mixed and pure stands. Soil type and moisture conditions (moderate drought) were expected to be the same at the beginning of the simulations irrespective of site location. Regardless of tree species, both annual net canopy photosynthesis (P(nc)) and total stem wood growth (V(s)) were, on average, lower on the southern site under the changing climate compared with the current climate (difference increasing toward the end of the rotation); the opposite was the case for the northern site. Regarding the stand water budget, evapotranspiration (E(T)) was higher under the changing climate regardless of site location. Transpiration and evaporation from the canopy affected water depletion the most. Norway spruce and birch accounted for most of the water depletion in mixed stands on both sites regardless of climatic condition. The annual soil water deficit (W(d)) was higher on the southern site under the changing climate. On the northern site, the situation was the opposite. According to our results, the growth of pure Norway spruce stands in southern Finland could be even lower than the growth of Norway spruce in mixed stands under the changing climate. The opposite was found for pure Scots pine and birch stands due to lower water depletion. This indicates that in the future the management should be properly adapted to climate change in order to

  5. Characterisation of the initial degradation stage of Scots pine (Pinus sylvestris L.) sapwood after attack by brown-rot fungus Coniophora puteana.

    PubMed

    Irbe, Ilze; Andersone, Ingeborga; Andersons, Bruno; Noldt, Guna; Dizhbite, Tatiana; Kurnosova, Nina; Nuopponen, Mari; Stewart, Derek

    2011-07-01

    In our study, early period degradation (10 days) of Scots pine (Pinus sylvestris L.) sapwood by the brown-rot fungus Coniophora puteana (Schum.: Fr.) Karst. (BAM Ebw.15) was followed at the wood chemical composition and ultrastructure-level, and highlighted the generation of reactive oxygen species (ROS). An advanced decay period of 50 days was chosen for comparison of the degradation dynamics. Scanning UV microspectrophotometry (UMSP) analyses of lignin distribution in wood cells revealed that the linkages of lignin and polysaccharides were already disrupted in the early period of fungal attack. An increase in the lignin absorption A(280) value from 0.24 (control) to 0.44 in decayed wood was attributed to its oxidative modification which has been proposed to be generated by Fenton reaction derived ROS. The wood weight loss in the initial degradation period was 2%, whilst cellulose and lignin content decreased by 6.7% and 1%, respectively. Lignin methoxyl (-OCH3) content decreased from 15.1% (control) to 14.2% in decayed wood. Diffuse reflectance Fourier-transform infrared (DRIFT) spectroscopy corroborated the moderate loss in the hemicellulose and lignin degradation accompanying degradation. Electron paramagnetic resonance spectra and spin trapping confirmed the generation of ROS, such as hydroxyl radicals (HO∙), in the early wood degradation period. Our results showed that irreversible changes in wood structure started immediately after wood colonisation by fungal hyphae and the results generated here will assist in the understanding of the biochemical mechanisms of wood biodegradation by brown-rot fungi with the ultimate aim of developing novel wood protection methods. PMID:21327804

  6. Measuring and modelling the intra-day variability of the 13CO2 & 12CO2 vertical soil profile production in a Scots pine forest

    NASA Astrophysics Data System (ADS)

    Longdoz, Bernard; Goffin, Stéphanie; Parent, Florian; Plain, Caroline; Epron, Daniel; Wylock, Christophe; Haut, Benoit; Aubinet, Marc; Maier, Martin

    2015-04-01

    Vertical profile of CO2 production (Ps) and transport, as well as their isotopic discrimination (13CO2/12CO2) should be considered to improve the soil CO2 efflux (Fs) mechanistic understanding and especially its short-term temporal variations. In this context, we propose a new methodology able to measure continuously and simultaneously Fs, the vertical soil CO2 concentration ([CO2]) profile and their respective isotopic signature (δFs and δCO2) [1]. The Ps of the different soil layers and their isotopic signature (δPs) can then be determined from these measurements by an approach considering diffusion as the only gas transport. A field campaign was conducted with this device at the Scots Pine Hartheim forest (Germany). The results [2] show (i) a Ps dependence on local temperature specific for each layer, (ii) an enrichment of δPs with soil drought, (iii) Fs and [CO2] large intra-day fluctuations non explained by the soil temperature and moisture. These fluctuations can be generated by other processes creating Ps and/or transport variability. To investigate about the nature of these processes, some sensitivity analyses have been performed with a soil CO2 model simulating both production and transport. The impacts of the introduction of advection, dispersion and phloem pressure concentration wave (through dependence of Ps on vapour pressure deficit) on intra-day Fs and [CO2] variations have been quantified. We conclude that these variations are significantly better represented when the phloem pressure wave expression is included in the simulations. The study of the processes related to CO2 production seems to be a better option than an investigation about transport to explain the intra-day Fs variability.

  7. Impact of emission from oil shale fueled power plants on the growth and foliar elemental concentrations of Scots pine in Estonia.

    PubMed

    Ots, Katri

    2003-07-01

    To study the impact of air pollution on the growth and elemental composition of conifers, 5 sample plots were established at different distances and directions from the Estonian Power Plant (Northeast Estonia) in 1999-2000. The selected stands were 75-80(85)-yr-old parts (0.05 ha) of (Oxalis)-Myrtillus site type forest of 0.7-0.8 density. The soils of all sample plots were Gleyic Podzols (Lkg) on sands. The several times higher Ca concentration in the humus horizon of the sample plot NE from the Estonian PP is caused by the prevailing westerly and southerly winds which carry more pollutants NE from the power plant than to SSW. To ascertain the effect of power plants on the growth of Scots pine (Pinus sylvestris L.), the length growth of the needles and shoots formed in 1997-2000, dry weight of 100 needles, and density of needles on the shoots were measured. As compared to the control, the strongest inhibition of growth was revealed in the sample plots situated 22 km north-east and 17 km south-west from the Estonian Power Plant. As compared to control, the needles of trees growing on sample plots closer to the power plant showed higher contents of Ca, S and Zn. The content of Mg in needles increased with distance from the pollution source. Current year needles had higher contents of Cu and Zn than older needles. Today the amounts of fly ash emitted from Narva power plants are fallen. Long-term fly ash emission has caused changes in the measurements of morphological parameters and chemical composition of needles. PMID:12841691

  8. High genetic diversity at the extreme range edge: nucleotide variation at nuclear loci in Scots pine (Pinus sylvestris L.) in Scotland

    PubMed Central

    Wachowiak, W; Salmela, M J; Ennos, R A; Iason, G; Cavers, S

    2011-01-01

    Nucleotide polymorphism at 12 nuclear loci was studied in Scots pine populations across an environmental gradient in Scotland, to evaluate the impacts of demographic history and selection on genetic diversity. At eight loci, diversity patterns were compared between Scottish and continental European populations. At these loci, a similar level of diversity (θsil=∼0.01) was found in Scottish vs mainland European populations, contrary to expectations for recent colonization, however, less rapid decay of linkage disequilibrium was observed in the former (ρ=0.0086±0.0009, ρ=0.0245±0.0022, respectively). Scottish populations also showed a deficit of rare nucleotide variants (multi-locus Tajima's D=0.316 vs D=−0.379) and differed significantly from mainland populations in allelic frequency and/or haplotype structure at several loci. Within Scotland, western populations showed slightly reduced nucleotide diversity (πtot=0.0068) compared with those from the south and east (0.0079 and 0.0083, respectively) and about three times higher recombination to diversity ratio (ρ/θ=0.71 vs 0.15 and 0.18, respectively). By comparison with results from coalescent simulations, the observed allelic frequency spectrum in the western populations was compatible with a relatively recent bottleneck (0.00175 × 4Ne generations) that reduced the population to about 2% of the present size. However, heterogeneity in the allelic frequency distribution among geographical regions in Scotland suggests that subsequent admixture of populations with different demographic histories may also have played a role. PMID:20823905

  9. Large-scale asymmetric introgression of cytoplasmic DNA reveals Holocene range displacement in a North American boreal pine complex.

    PubMed

    Godbout, Julie; Yeh, Francis C; Bousquet, Jean

    2012-08-01

    Jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta var. latifolia) are two North American boreal hard pines that hybridize in their zone of contact in western Canada. The main objective of this study was to characterize their patterns of introgression resulting from past and recent gene flow, using cytoplasmic markers having maternal or paternal inheritance. Mitochondrial DNA (mtDNA) and chloroplast DNA (cpDNA) diversity was assessed in allopatric populations of each species and in stands from the current zone of contact containing morphological hybrids. Cluster analyses were used to identify genetic discontinuities among groups of populations. A canonical analysis was also conducted to detect putative associations among cytoplasmic DNA variation, tree morphology, and site ecological features. MtDNA introgression was extensive and asymmetric: it was detected in P. banksiana populations from the hybrid zone and from allopatric areas, but not in P. contorta populations. Very weak cpDNA introgression was observed, and only in P. banksiana populations. The mtDNA introgression pattern indicated that central Canada was first colonized by migrants from a P. contorta glacial population located west of the Rocky Mountains, before being replaced by P. banksiana migrating westward during the Holocene. In contrast, extensive pollen gene flow would have erased the cpDNA traces of this ancient presence of P. contorta. Additional evidence for this process was provided by the results of canonical analysis, which indicated that the current cpDNA background of trees reflected recent pollen gene flow from the surrounding dominant species rather than historical events that took place during the postglacial colonization. PMID:22957188

  10. Carbon Emission from Forest Fires on Scots Pine Logging Sites in the Angara Region of Central Siberia

    NASA Astrophysics Data System (ADS)

    Ivanova, G. A.; Conard, S. G.; McRae, D. J.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Kovaleva, N. M.

    2010-12-01

    Wildfire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares in Siberia. Logged sites are characterized by higher fire hazard than forest sites due to the presence of generally untreated logging slash (i.e., available fuel) which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population; this increases the risk for fire ignition. Fire impacts on the overstory trees, subcanopy woody layer, and ground vegetation biomass were estimated on 14 logged and unlogged comparison sites in the Lower Angara Region in 2009-2010 as part of the NASA-funded NEESPI project, The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia. Based on calculated fuel consumption, we estimated carbon emission from fires on both logged and unlogged burned sites. Carbon emission from fires on logged sites appeared to be twice that on unlogged sites. Soil respiration decreased on both site types after fires. This reduction may partially offset fire-produced carbon emissions. Carbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

  11. Mistletoe effects on Scots pine decline following drought events: insights from within-tree spatial patterns, growth and carbohydrates.

    PubMed

    Sangüesa-Barreda, Gabriel; Linares, Juan Carlos; Camarero, J Julio

    2012-05-01

    Forest decline has been attributed to the interaction of several stressors including biotic factors such as mistletoes and climate-induced drought stress. However, few data exist on how mistletoes are spatially arranged within trees and how this spatial pattern is related to changes in radial growth, responses to drought stress and carbon use. We used dendrochronology to quantify how mistletoe (Viscum album L.) infestation and drought stress affected long-term growth patterns in Pinus sylvestris L. at different heights. Basal area increment (BAI) trends and comparisons between trees of three different infestation degrees (without mistletoe, ID1; moderately infested trees, ID2; and severely infested trees, ID3) were performed using linear mixed-effects models. To identify the main climatic drivers of tree growth tree-ring widths were converted into indexed chronologies and related to climate data using correlation functions. We performed spatial analyses of the 3D distribution of mistletoe individuals and their ages within the crowns of three severely infested pines to describe their patterns. Lastly, we quantified carbohydrate and nitrogen concentrations in needles and sapwood of branches from severely infested trees and from trees without mistletoe. Mistletoe individuals formed strongly clustered groups of similar age within tree crowns and their age increased towards the crown apex. Mistletoe infestation negatively impacted growth but this effect was stronger near the tree apex than in the rest of sampled heights, causing an average loss of 64% in BAI (loss of BAI was ∼51% at 1.3 m or near the tree base). We found that BAI of severely infested trees and moderately or non-infested trees diverged since 2001 and such divergence was magnified by drought. Infested trees had lower concentrations of soluble sugars in their needles than non-infested ones. We conclude that mistletoe infestation causes growth decline and increases the sensitivity of trees to drought

  12. Oxygen-18 and deuterium spatio-temporal variability in throughfall and stemflow in Scots pine and Downy oaks forests under Mediterranean climate

    NASA Astrophysics Data System (ADS)

    Cayuela, Carles; Sánchez-Costa, Elisenda; Latron, Jérôme; Llorens, Pilar

    2016-04-01

    Rainfall partitioning processes can be better understood complementing classical hydrometric techniques with water isotopes. Oxygen-18 and deuterium can be used to shed some light on mechanisms of rainfall evaporation from the canopies, and their relationship with canopy and meteorological variables that are not completely understood. Several mechanisms have been described to explain the differences between event-scale bulk rainfall and throughfall isotopic compositions (i.e. evaporation, selective storage, exchange with ambient vapor, residual moisture), and their relation to factors like the amount of water held in the forest canopy, rainfall intensity, time interval between rainfall events, or meteorological conditions. However, there are much fewer studies examining the spatio-temporal variability of isotopic composition in both throughfall and stemflow along rainfall events. This study aims to characterize the water stable isotopes spatio-temporal variability in throughfall and stemflow in a Downy oak (Quercus pubescens) and a Scots pine (Pinus sylvestris) forests located in the Vallcebre research catchments (NE Spain, 42° 12'N, 1° 49'E), under Mediterranean climate conditions. The isotopic sampling design of each stand consisted of one automatic sampler to sample the temporal variability of throughfall signature every 5 mm of rainfall, 10 throughfall collectors distributed within the stand to sample the spatial variability and 4 stemflow collectors. Bulk rainfall was collected with automatic samplers and bulk collectors in two open areas near each forest plot. At each stand isotopic sampling was combined with hydrometric measurements that consisted of 20 tipping buckets to measure throughfall spatial variability and 7 stemflow rings connected to tipping buckets to measure stemflow depth. Moreover, rainfall depth was measured in the open areas and meteorological variables in two towers located above canopies. The study started on May 2015 and is still in

  13. Biogenic volatile organic compounds (BVOCs) emission of Scots pine under drought stress - a 13CO2 labeling study to determine de novo and pool emissions under different treatments

    NASA Astrophysics Data System (ADS)

    Lüpke, M.

    2015-12-01

    Plants emit biogenic volatile organic compounds (BVOCs) to e.g. communicate and to defend herbivores. Yet BVOCs also impact atmospheric chemistry processes, and lead to e.g. the built up of secondary organic aerosols. Abiotic stresses, such as drought, however highly influence plant physiology and subsequently BVOCs emission rates. In this study, we investigated the effect of drought stress on BVOCs emission rates of Scots pine trees, a de novo and pool emitter, under controlled climate chamber conditions within a dynamic enclosure system consisting of four plant chambers. Isotopic labeling with 13CO2 was used to detect which ratio of emissions of BVOCs derives from actual synthesis and from storage organs under different treatments. Additionally, the synthesis rate of the BVOCs synthesis can be determined. The experiment consisted of two campaigns (July 2015 and August 2015) of two control and two treated trees respectively in four controlled dynamic chambers simultaneously. Each campaign lasted for around 21 days and can be split into five phases: adaptation, control, dry-out, drought- and re-watering phase. The actual drought phase lasted around five days. During the campaigns two samples of BVOCs emissions were sampled per day and night on thermal desorption tubes and analyzed by a gas chromatograph coupled with a mass spectrometer and a flame ionization detector. Additionally, gas exchange of water and CO2, soil moisture, as well as leaf and chamber temperature was monitored continuously. 13CO2 labeling was performed simultaneously in all chambers during the phases control, drought and re-watering for five hours respectively. During the 13CO2 labeling four BVOCs emission samples per chamber were taken to identify the labeling rate on emitted BVOCs. First results show a decrease of BVOCs emissions during the drought phase and a recovery of emission after re-watering, as well as different strength of reduction of single compounds. The degree of labeling with 13

  14. Environmental impact assessment and monetary ecosystem service valuation of an ecosystem under different future environmental change and management scenarios; a case study of a Scots pine forest.

    PubMed

    Schaubroeck, Thomas; Deckmyn, Gaby; Giot, Olivier; Campioli, Matteo; Vanpoucke, Charlotte; Verheyen, Kris; Rugani, Benedetto; Achten, Wouter; Verbeeck, Hans; Dewulf, Jo; Muys, Bart

    2016-05-15

    For a sustainable future, we must sustainably manage not only the human/industrial system but also ecosystems. To achieve the latter goal, we need to predict the responses of ecosystems and their provided services to management practices under changing environmental conditions via ecosystem models and use tools to compare the estimated provided services between the different scenarios. However, scientific articles have covered a limited amount of estimated ecosystem services and have used tools to aggregate services that contain a significant amount of subjective aspects and that represent the final result in a non-tangible unit such as 'points'. To resolve these matters, this study quantifies the environmental impact (on human health, natural systems and natural resources) in physical units and uses an ecosystem service valuation based on monetary values (including ecosystem disservices with associated negative monetary values). More specifically, the paper also focuses on the assessment of ecosystem services related to pollutant removal/generation flows, accounting for the inflow of eutrophying nitrogen (N) when assessing the effect of N leached to groundwater. Regarding water use/provisioning, evapotranspiration is alternatively considered a disservice because it implies a loss of (potential) groundwater. These approaches and improvements, relevant to all ecosystems, are demonstrated using a Scots pine stand from 2010 to 2089 for a combination of three environmental change and three management scenarios. The environmental change scenarios considered interannual climate variability trends and included alterations in temperature, precipitation, nitrogen deposition, wind speed, Particulate matter (PM) concentration and CO2 concentration. The addressed flows/ecosystem services, including disservices, are as follows: particulate matter removal, freshwater loss, CO2 sequestration, wood production, NOx emissions, NH3 uptake and nitrogen pollution/removal. The monetary

  15. Intra-seasonal dynamics in metabolic processes of 13C/12C and 18O/16O in components of Scots pine twigs from southern Siberia interpreted with a conceptual framework based on the Carbon Metabolism Oscillatory Model

    PubMed Central

    2012-01-01

    Background Carbon isotope data from conifer trees play an important role in research on the boreal forest carbon reservoir in the global carbon cycle. Carbon isotopes are routinely used to study interactions between the environment and tree growth. Moreover, carbon isotopes became an essential tool for the evaluation of carbon assimilation and transport from needles into reserve pools, as well as the allocation of stored assimilates within a tree. The successful application and interpretation of carbon isotopes rely on the coherence of isotopic fractionation modeling. This study employs a new Carbon Metabolism Oscillatory Model (CMOM) to interpret the experimental data sets on metabolic seasonal dynamics of 13C/12 C and 18O/16O ratios measured in twig components of Scots pine growing in southern Siberia (Russia). Results The dynamics of carbon isotopic variables were studied in components of Pinus sylvestris L. in light and in dark chambers during the vegetation period from 14 June to 28 July 2006. At the beginning of this period water-soluble organic matter, mostly labile sugars (including sucrose as the main component) and newly formed bulk needle material, displayed relatively “light” δ13C values (depletion in 13 C). Then, 13 C content increased again with noticeable “depletion” events in the middle of the growth period. A gradual 13 C accumulation took place in the second half of the vegetation period. Similar effects were observed both in the light and in the dark with some temporal shifts. Environmental factors did not influence the δ13C values. A gradual 12C-depletion effect was noticed in needles of the previous year. The δ13C values of sucrose and proteins from needle biomass altered independently from each other in the light chamber. A distinct negative correlation between δ13C and δ18O values was revealed for all studied variables. Conclusions The abrupt 13C depletion recorded by all tested trees for the period from June to July

  16. Singular and interactive effects of blowdown, salvage logging, and wildfire in sub-boreal pine systems

    USGS Publications Warehouse

    D'Amato, A.W.; Fraver, S.; Palik, B.J.; Bradford, J.B.; Patty, L.

    2011-01-01

    The role of disturbance in structuring vegetation is widely recognized; however, we are only beginning to understand the effects of multiple interacting disturbances on ecosystem recovery and development. Of particular interest is the impact of post-disturbance management interventions, particularly in light of the global controversy surrounding the effects of salvage logging on forest ecosystem recovery. Studies of salvage logging impacts have focused on the effects of post-disturbance salvage logging within the context of a single natural disturbance event. There have been no formal evaluations of how these effects may differ when followed in short sequence by a second, high severity natural disturbance. To evaluate the impact of this management practice within the context of multiple disturbances, we examined the structural and woody plant community responses of sub-boreal Pinus banksiana systems to a rapid sequence of disturbances. Specifically, we compared responses to Blowdown (B), Fire (F), Blowdown-Fire, and Blowdown-Salvage-Fire (BSF) and compared these to undisturbed control (C) stands. Comparisons between BF and BSF indicated that the primary effect of salvage logging was a decrease in the abundance of structural legacies, such as downed woody debris and snags. Both of these compound disturbance sequences (BF and BSF), resulted in similar woody plant communities, largely dominated by Populus tremuloides; however, there was greater homogeneity in community composition in salvage logged areas. Areas experiencing solely fire (F stands) were dominated by P. banksiana regeneration, and blowdown areas (B stands) were largely characterized by regeneration from shade tolerant conifer species. Our results suggest that salvage logging impacts on woody plant communities are diminished when followed by a second high severity disturbance; however, impacts on structural legacies persist. Provisions for the retention of snags, downed logs, and surviving trees as part

  17. Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest

    PubMed Central

    Machacova, Katerina; Bäck, Jaana; Vanhatalo, Anni; Halmeenmäki, Elisa; Kolari, Pasi; Mammarella, Ivan; Pumpanen, Jukka; Acosta, Manuel; Urban, Otmar; Pihlatie, Mari

    2016-01-01

    Boreal forests comprise 73% of the world’s coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories. PMID:26997421

  18. Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest

    NASA Astrophysics Data System (ADS)

    Machacova, Katerina; Bäck, Jaana; Vanhatalo, Anni; Halmeenmäki, Elisa; Kolari, Pasi; Mammarella, Ivan; Pumpanen, Jukka; Acosta, Manuel; Urban, Otmar; Pihlatie, Mari

    2016-03-01

    Boreal forests comprise 73% of the world’s coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories.

  19. Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest.

    PubMed

    Machacova, Katerina; Bäck, Jaana; Vanhatalo, Anni; Halmeenmäki, Elisa; Kolari, Pasi; Mammarella, Ivan; Pumpanen, Jukka; Acosta, Manuel; Urban, Otmar; Pihlatie, Mari

    2016-01-01

    Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories. PMID:26997421

  20. Scots pine needles macronutrient (N, P, K, CA, MG, and S) supply at different reclaimed mine soil substrates--as an indicator of the stability of developed forest ecosystems.

    PubMed

    Pietrzykowski, Marcin; Woś, Bartłomiej; Haus, Nicholas

    2013-09-01

    A main objective of restoration and afforestation at post-mining sites is establishing a long-term sustainable ecosystem which depends on adaptations of tree species and which in turn depends on the soil nutrient flux. The nutrient concentration (nitrogen (N), P, K, Ca, Mg, and sulfur (S)) of Scots pine needles was investigated in reclaimed mine soils (RMS) located at the following post-mining sites: a sand mine pit, spoil heap from a lignite mine, spoil heap from a S mine, and a carbonaceous spoil heap from an underground coal mine. The control plots were arranged on natural forest sites adjacent to the post-mining sites. A higher level of foliar nutrients was noted in the carbonaceous RMS, while lower levels were found in RMS on the spoil heap following lignite mining. The characteristics of the substrate were found to exert greater effect than mineral fertilization (performed at the onset of reclamation) on the tree stand characteristics, needle length and foliar nutrient concentration. While the soils and trees were most deficient in N, negative symptoms have not been noted to this date in tree stands at reclaimed mine sites. Trophic ratings were recommended based on statistical correlations and groupings between N and P contents in needles and needles length (mean length of 300 needles) while nutrient ratings were recommended from statistical differences and groupings of the RMS substrates. PMID:23404547

  1. Spatial variability of throughfall in a stand of Scots pine (Pinus sylvestris L.) with deciduous admixture as influenced by canopy cover and stem distance

    NASA Astrophysics Data System (ADS)

    Kowalska, Anna; Boczoń, Andrzej; Hildebrand, Robert; Polkowska, Żaneta

    2016-07-01

    Vegetation cover affects the amount of precipitation, its chemical composition and its spatial distribution, and this may have implications for the distribution of water, nutrients and contaminants in the subsurface soil layer. The aim of this study was a detailed diagnosis of the spatio-temporal variability in the amount of throughfall (TF) and its chemical components in a 72-year-old pine stand with an admixture of oak and birch. The spatio-temporal variability in the amount of TF water and the concentrations and deposition of the TF components were studied. The components that are exchanged in canopy (H+, K, Mg, Mn, DOC, NH4+) were more variable than the components whose TF deposition is the sum of wet and dry (including gas) deposition and which undergo little exchange in the canopy (Na, Cl, NO3-, SO42-). The spatial distribution was temporally stable, especially during the leafed period. This study also investigated the effect of the selected pine stand characteristics on the spatial distribution of throughfall and its chemical components; the characteristics included leaf area index (LAI), the proportion of the canopy covered by deciduous species and pine crowns, and the distance from the nearest tree trunk. The LAI measured during the leafed and leafless periods had the greatest effect on the spatial distribution of TF deposition. No relationship was found between the spatial distribution of the amount of TF water and (i) the LAI; (ii) the canopy cover of broadleaf species or pines; or (iii) the distance from the trunks.

  2. Biotic stress accelerates formation of climate-relevant aerosols in boreal forests

    NASA Astrophysics Data System (ADS)

    Joutsensaari, J.; Yli-Pirilä, P.; Korhonen, H.; Arola, A.; Blande, J. D.; Heijari, J.; Kivimäenpää, M.; Mikkonen, S.; Hao, L.; Miettinen, P.; Lyytikäinen-Saarenmaa, P.; Faiola, C. L.; Laaksonen, A.; Holopainen, J. K.

    2015-04-01

    Boreal forests are a major source of climate-relevant biogenic secondary organic aerosols (SOA) and will be greatly influenced by increasing temperature. Global warming is predicted to increase emissions of reactive biogenic volatile organic compounds (BVOC) from vegetation directly, but will also induce large-scale insect outbreaks, which significantly increase emissions of reactive BVOC. Thus, climate change factors could substantially accelerate the formation of biogenic SOA in the troposphere. In this study, we have combined results from field and laboratory experiments, satellite observations and global scale modelling in order to evaluate the effects of insect herbivory and large-scale outbreaks on SOA formation and the Earth's climate. Field measurements demonstrated 11-fold and 20-fold increases in monoterpene and sesquiterpene emissions, respectively, from damaged trees during a pine sawfly (Neodiprion sertifer) outbreak in eastern Finland. Laboratory chamber experiments showed that feeding by pine weevils (Hylobius abietis) increased VOC emissions from Scots pine and Norway spruce seedlings by 10-50 fold resulting in 200-1000 fold increases in SOA masses formed via ozonolysis. The influence of insect damage on aerosol concentrations in boreal forests was studied with a global chemical transport model GLOMAP and MODIS satellite observations. Global scale modelling was performed using a 10-fold increase in monoterpene emission rates and assuming 10% of the boreal forest area was experiencing outbreak. Results showed a clear increase in total particulate mass (local max. 480%) and cloud condensation nuclei concentrations (45%). Satellite observations indicated a two-fold increase in aerosol optical depth (AOD) over western Canada's pine forests in August during a bark beetle outbreak. These results suggest that more frequent insect outbreaks in a warming climate could result in substantial increase in biogenic SOA formation in the boreal zone and, thus

  3. Biotic stress accelerates formation of climate-relevant aerosols in boreal forests

    NASA Astrophysics Data System (ADS)

    Joutsensaari, J.; Yli-Pirilä, P.; Korhonen, H.; Arola, A.; Blande, J. D.; Heijari, J.; Kivimäenpää, M.; Mikkonen, S.; Hao, L.; Miettinen, P.; Lyytikäinen-Saarenmaa, P.; Faiola, C. L.; Laaksonen, A.; Holopainen, J. K.

    2015-11-01

    Boreal forests are a major source of climate-relevant biogenic secondary organic aerosols (SOAs) and will be greatly influenced by increasing temperature. Global warming is predicted to not only increase emissions of reactive biogenic volatile organic compounds (BVOCs) from vegetation directly but also induce large-scale insect outbreaks, which significantly increase emissions of reactive BVOCs. Thus, climate change factors could substantially accelerate the formation of biogenic SOAs in the troposphere. In this study, we have combined results from field and laboratory experiments, satellite observations and global-scale modelling in order to evaluate the effects of insect herbivory and large-scale outbreaks on SOA formation and the Earth's climate. Field measurements demonstrated 11-fold and 20-fold increases in monoterpene and sesquiterpene emissions respectively from damaged trees during a pine sawfly (Neodiprion sertifer) outbreak in eastern Finland. Laboratory chamber experiments showed that feeding by pine weevils (Hylobius abietis) increased VOC emissions from Scots pine and Norway spruce seedlings by 10-50 fold, resulting in 200-1000-fold increases in SOA masses formed via ozonolysis. The influence of insect damage on aerosol concentrations in boreal forests was studied with a global chemical transport model GLOMAP and MODIS satellite observations. Global-scale modelling was performed using a 10-fold increase in monoterpene emission rates and assuming 10 % of the boreal forest area was experiencing outbreak. Results showed a clear increase in total particulate mass (local max. 480 %) and cloud condensation nuclei concentrations (45 %). Satellite observations indicated a 2-fold increase in aerosol optical depth over western Canada's pine forests in August during a bark beetle outbreak. These results suggest that more frequent insect outbreaks in a warming climate could result in substantial increase in biogenic SOA formation in the boreal zone and, thus

  4. Archaeal communities in boreal forest tree rhizospheres respond to changing soil temperatures.

    PubMed

    Bomberg, Malin; Münster, Uwe; Pumpanen, Jukka; Ilvesniemi, Hannu; Heinonsalo, Jussi

    2011-07-01

    Temperature has generally great effects on both the activity and composition of microbial communities in different soils. We tested the impact of soil temperature and three different boreal forest tree species on the archaeal populations in the bulk soil, rhizosphere, and mycorrhizosphere. Scots pine, silver birch, and Norway spruce seedlings were grown in forest humus microcosms at three different temperatures, 7-11.5°C (night-day temperature), 12-16°C, and 16-22°C, of which 12-16°C represents the typical mid-summer soil temperature in Finnish forests. RNA and DNA were extracted from indigenous ectomycorrhiza, non-mycorrhizal long roots, and boreal forest humus and tested for the presence of archaea by nested PCR of the archaeal 16S rRNA gene followed by denaturing gradient gel electrophoresis (DGGE) profiling and sequencing. Methanogenic Euryarchaeota belonging to Methanolobus sp. and Methanosaeta sp. were detected on the roots and mycorrhiza. The most commonly detected archaeal 16S rRNA gene sequences belonged to group I.1c Crenarchaeota, which are typically found in boreal and alpine forest soils. Interestingly, also one sequence belonging to group I.1b Crenarchaeota was detected from Scots pine mycorrhiza although sequences of this group are usually found in agricultural and forest soils in temperate areas. Tree- and temperature-related shifts in the archaeal population structure were observed. A clear decrease in crenarchaeotal DGGE band number was seen with increasing temperature, and correspondingly, the number of euryarchaeotal DGGE bands, mostly methanogens, increased. The greatest diversity of archaeal DGGE bands was detected in Scots pine roots and mycorrhizas. No archaea were detected from humus samples from microcosms without tree seedling, indicating that the archaea found in the mycorrhizosphere and root systems were dependent on the plant host. The detection of archaeal 16S rRNA gene sequences from both RNA and DNA extractions show that the

  5. Ground-fire effects on the composition of dissolved and total organic matter in forest floor and soil solutions from Scots pine forests in Germany: new insights from solid state 13C NMR analysis

    NASA Astrophysics Data System (ADS)

    Näthe, Kerstin; Michalzik, Beate; Levia, Delphis; Steffens, Markus

    2016-04-01

    Fires represent an ecosystem disturbance and are recognized to seriously pertubate the nutrient budgets of forested ecosystems. While the effects of fires on chemical, biological, and physical soil properties have been intensively studied, especially in Mediterranean areas and North America, few investigations examined the effects of fire-induced alterations in the water-bound fluxes and the chemical composition of dissolved and particulate organic carbon and nitrogen (DOC, POC, DN, PN). The exclusion of the particulate organic matter fraction (0.45 μm < POM < 500 μm) potentially results in misleading inferences and budgeting gaps when studying the effects of fires on nutrient and energy fluxes. To our best knowledge, this is the first known study to present fire-induced changes on the composition of dissolved and total organic matter (DOM, TOM) in forest floor (FF) and soil solutions (A, B horizon) from Scots pine forests in Germany. In relation to control sites, we test the effects of low-severity fires on: (1) the composition of DOM and TOM in forest floor and soil solutions; and (2) the translocated amount of particulate in relation to DOC and DN into the subsoil. The project aims to uncover the mechanisms of water-bound organic matter transport along an ecosystem profile and its compositional changes following a fire disturbance. Forest floor and soil solutions were fortnightly sampled from March to December 2014 on fire-manipulated and control plots in a Scots pine forest in Central Germany. Shortly after the experimental duff fire in April 2014 pooled solutions samples were taken for solid-state 13C NMR spectroscopy to characterize DOM (filtered solution < 0.8μm pore size) and TOM in unfiltered solutions. Independent from fire manipulation, the composition of TOM was generally less aromatic (aromaticity index [%] according to Hatcher et al., 1981) with values between 18 (FF) - 25% (B horizon) than the DOM fraction with 23 (FF) - 27% (B horizon). For DOM

  6. Determination of de novo and pool emissions of terpenes from four common boreal/alpine trees by 13CO2 labelling and PTR-MS analysis.

    PubMed

    Ghirardo, Andrea; Koch, Kristine; Taipale, Risto; Zimmer, Ina; Schnitzler, Jörg-Peter; Rinne, Janne

    2010-05-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus, their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS, we determined the fractions of monoterpene emissions originating from de novo biosynthesis in Pinus sylvestris (58%), Picea abies (33.5%), Larix decidua (9.8%) and Betula pendula (100%). Application of the observed split between de novo and pool emissions from P. sylvestris in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand. PMID:20040067

  7. Soil moisture sensitivity of autotrophic and heterotrophic forest floor respiration in boreal xeric pine and mesic spruce forests

    NASA Astrophysics Data System (ADS)

    Ťupek, Boris; Launiainen, Samuli; Peltoniemi, Mikko; Heikkinen, Jukka; Lehtonen, Aleksi

    2016-04-01

    Litter decomposition rates of the most process based soil carbon models affected by environmental conditions are linked with soil heterotrophic CO2 emissions and serve for estimating soil carbon sequestration; thus due to the mass balance equation the variation in measured litter inputs and measured heterotrophic soil CO2 effluxes should indicate soil carbon stock changes, needed by soil carbon management for mitigation of anthropogenic CO2 emissions, if sensitivity functions of the applied model suit to the environmental conditions e.g. soil temperature and moisture. We evaluated the response forms of autotrophic and heterotrophic forest floor respiration to soil temperature and moisture in four boreal forest sites of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) by a soil trenching experiment during year 2015 in southern Finland. As expected both autotrophic and heterotrophic forest floor respiration components were primarily controlled by soil temperature and exponential regression models generally explained more than 90% of the variance. Soil moisture regression models on average explained less than 10% of the variance and the response forms varied between Gaussian for the autotrophic forest floor respiration component and linear for the heterotrophic forest floor respiration component. Although the percentage of explained variance of soil heterotrophic respiration by the soil moisture was small, the observed reduction of CO2 emissions with higher moisture levels suggested that soil moisture response of soil carbon models not accounting for the reduction due to excessive moisture should be re-evaluated in order to estimate right levels of soil carbon stock changes. Our further study will include evaluation of process based soil carbon models by the annual heterotrophic respiration and soil carbon stocks.

  8. The Effect of Bark Borer Herbivory on BVOC Emissions in Boreal Forests and Implications for SOA Formation

    NASA Astrophysics Data System (ADS)

    Faiola, Celia; Joutsensaari, Jorma; Holopainen, Jarmo; Yli-Juuti, Taina; Kokkola, Harri; Blande, James; Guenther, Alex; Virtanen, Annele

    2015-04-01

    Herbivore outbreaks are expected to increase as a result of climate change. These outbreaks can have significant effects on the emissions of biogenic volatile organic compound (BVOC) from vegetation, which contribute to the formation of secondary organic aerosol (SOA). We have synthesized the published results investigating changes to BVOC emissions from herbivory by the pine weevil, Hylobius abietis--a bark borer herbivore. Previous lab experiments have shown that bark borer herbivory on Scots pine trees increases monoterpene emissions 4-fold and sesquiterpene emissions 7-fold. Norway spruce exhibits a similar response. The BVOCs most impacted were linalool, beta-phellandrene, limonene, alpha-pinene, beta-pinene, myrcene, and sesquiterpenes like beta-farnesene, beta-bourbonene, and longifolene. The quantitative results from these studies were used to estimate potential impacts of bark borer herbivory on BVOC emissions at a regional scale using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). MEGAN was run under baseline and herbivore outbreak conditions for a typical boreal forest environment in spring. Emissions output from MEGAN was used to run a microphysical box model to estimate the SOA formation potential under baseline and outbreak conditions. This estimate could provide us with an upper limit to the potential impact of bark borer outbreaks on SOA formation in a boreal forest.

  9. Nitrogen balance along a boreal forest fire chronosequence

    NASA Astrophysics Data System (ADS)

    Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

    2016-04-01

    Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change in boreal regions. Because boreal forests comprise 30% of the global forest area, increases in the annual area burned may have significant implications for global carbon and nitrogen (N) cycles. The productivity of boreal forests is limited by low N availability. Fires cause N loss from ecosystems through oxidation and volatilization of N stored in biomass and soil. N balance may be poorly buffered against forest fires especially in sub-arctic ecosystems where atmospheric N deposition is low. Although forest fires alter N dynamics, there are little quantitative data available on N pools and fluxes through post-fire succession in sub-arctic boreal forests. We studied changes in N pools and fluxes, and the overall N balance across a 155-year forest fire chronosequence in sub-arctic Scots pine (Pinus sylvestris) forests in Värriö Strict Nature Reserve situated in Finnish Lapland (67°46' N, 29°35' E). Soil was the largest N pool in all forest age classes and comprised 69-82% of the total ecosystem N pool. The total ecosystem N pool varied from 622 kg ha-1 in the recently burned forest to 960 kg ha-1 in the 155-year-old forest. The forests were N sinks in all age classes the annual N accumulation rate being 2.28 kg ha-1 yr-1 which was distributed almost equally between soil and biomass. The observed changes in ecosystem N pools were consistent with the computed N balance 2.10 kg ha-1 yr-1 over the 155-year post-fire period (Balance= (atmospheric deposition + N fixation) - (leaching + N2O emissions)). The results indicated that N deposition is an important component of the N balance and the N outputs are small (13% of the inputs) in the studied ecosystems. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) compared to the other N fluxes. The biological N fixation increased with succession and constituted 9% of the total N

  10. Origin of monoterpene emissions from boreal tree species: Determination of de novo and pool emissions by 13CO2 labeling

    NASA Astrophysics Data System (ADS)

    Rinne, J.; Ghirardo, A.; Koch, K.; Taipale, R.; Zimmer, I.; Schnitzler, J.

    2009-12-01

    Boreal forests emit a large amount of monoterpenes into the atmosphere. Traditionally these emissions are assumed to originate as evaporation from large storage pools. Thus their diurnal cycle would depend mostly on temperature. However, there is indication that a significant part of the monoterpene emission would originate directly from de novo synthesis. By applying 13CO2 fumigation and analyzing the isotope fractions with proton transfer reaction mass spectrometry (PTR-MS) and classical GC-MS we studied the origin of monoterpene emissions from some major Eurasian boreal and alpine tree species. We determined the fractions originating from de novo biosynthesis and from large internal monoterpene storages for three coniferous tree species with specialized monoterpene storage structures and one dicotyledon species without such structures. The emission from dicotyledon species Betula pendula originated solely from the de novo synthesis. The origin of the emissions from coniferous species was mixed with varying fraction originating from de novo synthesis (Pinus sylvestris 58%, Picea abies 33.5%, Larix decidua 9.8%) and the rest from large internal monoterpene storage pools. Application of the observed fractions of emission originating from de novo synthesis and large storage pools in a hybrid emission algorithm resulted in a better description of ecosystem scale monoterpene emissions from a boreal Scots pine forest stand.

  11. Estimation of autotrophic soil respiration in a boreal forest using three different approaches

    NASA Astrophysics Data System (ADS)

    Kulmala, Liisa; Pumpanen, Jukka; Heinonsalo, Jussi

    2016-04-01

    It is generally challenging to separate autotrophic and heterotrophic soil respiration. The reason for these difficulties is connected with the intimate interaction of the key processes in soil. Root-associated microbes practically colonize the whole soil volume while decomposition processes occur in the same matrix. Therefore, autotrophic and heterotrophic processes cannot be separated in natural systems. However, there are several methods that can be used to better understand the dynamics of these two. A classical method is called 'trenching' where a trench is dug around a known volume of soil and the roots entering the soil are cut from the living trees thus blocking the C flow from them. The second way to separate autotrophic and heterotrophic respiration relies on the difference in the isotopic signature (13C) of plant-derived or decomposition-derived CO2. The third way to separate the sources is to study the differences in the short- and long-term temperature dependencies in CO2 soil emissions. This is possible especially in boreal forests where the biological activity has a strong seasonal cycle. We compared these three methods in an experiment conducted in a southern boreal middle-aged Scots pine stand in Finland. Our data provides a unique possibility to critically evaluate current methods for estimating autotrophic and heterotrophic soil respiration. The knowledge is needed to study further plant physiology and plant-microbe interactions in soil.

  12. Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest

    NASA Astrophysics Data System (ADS)

    Aaltonen, H.; Pumpanen, J.; Hakola, H.; Vesala, T.; Rasmus, S.; Bäck, J.

    2012-01-01

    Soil forms an important source for volatile organic compounds (VOCs), but in boreal forests these fluxes and their seasonal variations have not been characterized in detail, especially wintertime fluxes, which are almost completely unstudied. In this study, we measured the VOC concentrations inside a snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m-3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from the soil surface towards the snow surface, suggesting soil as being the source for terpenoids. Forest damages resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are also active and efficient VOC sources during winter and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, basically plants, have lower activity.

  13. Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest

    NASA Astrophysics Data System (ADS)

    Aaltonen, H.; Pumpanen, J.; Hakola, H.; Vesala, T.; Rasmus, S.; Bäck, J.

    2012-06-01

    Soil provides an important source of volatile organic compounds (VOCs) to atmosphere, but in boreal forests these fluxes and their seasonal variations have not been characterized in detail. Especially wintertime fluxes are almost completely unstudied. In this study, we measured the VOC concentrations inside the snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m-3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from soil surface towards the surface of the snow, suggesting soil as the source for terpenoids. Forest damages (i.e. broken treetops and branches, fallen trees) resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are active and efficient VOC sources also during winter, and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, such as plants, have lower activity.

  14. Light-induced diurnal pattern of methane exchange in a boreal forest

    NASA Astrophysics Data System (ADS)

    Sundqvist, Elin; Crill, Patrick; Mölder, Meelis; Vestin, Patrik; Lindroth, Anders

    2013-04-01

    Boreal forests represents one third of the Earth's forested land surface area and is a net sink of methane and an important component of the atmospheric methane budget. Methane is oxidized in well-aerated forest soils whereas ponds and bog soils are sources of methane. Besides the microbial processes in the soil also forest vegetation might contribute to methane exchange. Due to a recent finding of methane consumption by boreal plants that correlated with photosynthetic active radiation (PAR), we investigate the impact of PAR on soil methane exchange at vegetated plots on the forest floor. The study site, Norunda in central Sweden, is a 120 years old boreal forest stand, dominated by Scots pine and Norway spruce. We used continuous chamber measurements in combination with a high precision laser gas analyzer (Los Gatos Research), to measure the methane exchange at four different plots in July-November 2009, and April-June 2010. The ground vegetation consisted almost entirely of mosses and blueberry-shrubs. Two of the plots acted as stable sinks of methane whereas the other two plots shifted from sinks to sources during very wet periods. The preliminary results show a clear diurnal pattern of the methane exchange during the growing season, which cannot be explained by temperature. The highest consumption occurs at high PAR levels. The amplitude of the diurnal methane exchange during the growing season is in the order of 10 μmol m-2 h-1. This indicates that besides methane oxidation by methanotrophs in the soil there is an additional removal of methane at soil level by a process related to ground vegetation.

  15. Intra-annual variability of anatomical structure and δ13C values within tree rings of spruce and pine in alpine, temperate and boreal Europe

    PubMed Central

    Vaganov, Eugene A.; Skomarkova, Marina V.; Knohl, Alexander; Brand, Willi A.; Roscher, Christiane

    2009-01-01

    Tree-ring width, wood density, anatomical structure and 13C/12C ratios expressed as δ13C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, δ13C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained <20% of the variation in tree-ring width and wood density over consecutive years, while 29–58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and δ13C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The δ13C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between δ13C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the δ13C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its linkage

  16. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences

    NASA Astrophysics Data System (ADS)

    Williams, J.; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä, T.; Rinne, J.; Bäck, J.; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, T.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, N.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, N.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K.; Breitenberger, C.; Hidalgo, P. J.; Ebben, C. J.; Geiger, F. M.; Corrigan, A. L.; Russell, L. M.; Ouwersloot, H. G.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C. J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.-L.; Kulmala, M.; Lelieveld, J.

    2011-10-01

    This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12 July-12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  17. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences

    NASA Astrophysics Data System (ADS)

    Williams, J.; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä, T.; Rinne, J.; Bäck, J.; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, T.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, N.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, N.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K.; Breitenberger, C.; Hidalgo, P. J.; Ebben, C. J.; Geiger, F. M.; Corrigan, A. L.; Russell, L. M.; Ouwersloot, H.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C. J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.-L.; Kulmala, M.; Lelieveld, J.

    2011-05-01

    This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12 July-12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site were characterized by a higher proportion of southerly flow. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  18. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences.

    NASA Astrophysics Data System (ADS)

    Williams, J.; Petäjä, T.

    2012-04-01

    This submission describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12th July-12th August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  19. Seasonal courses revealed that boreal trees emit methane even during winter time

    NASA Astrophysics Data System (ADS)

    Machacova, Katerina; Halmeenmäki, Elisa; Pihlatie, Mari; Urban, Otmar

    2016-04-01

    Boreal forests are considered to be a significant natural sink of methane (CH4) due to predominant soil deposition of CH4 from the atmosphere. However, plants are known to contribute to the CH4 exchange with the atmosphere. Fluxes of CH4 have been mostly studied on herbaceous plants, whereas investigations on trees, particularly boreal tree species, are sporadic. Therefore we determined CH4 fluxes from common boreal tree species: Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and silver birch (Betula pendula). The objectives were to investigate whether these tree species contribute to CH4 exchange with the atmosphere, particularly in winter, how soil water content affects these fluxes, and how trees contribute to overall forest CH4 fluxes. The measurements were performed on mature trees in the boreal forest surrounding the SMEAR II station in Finland. Fluxes of CH4 at stem and forest floor level were simultaneously measured over the whole year (from June 2014 until May 2015) using static chamber systems and quantified by gas chromatographic analyses. Our results show that the trees mostly emitted CH4 in the summer. Birch was the strongest emitter of CH4(9.5 μg CH4 m‑2stem area h‑1, medians) among the tree species studied, particularly under high soil volumetric water content (0.92 ± 0.01 m3 m‑3). Similarly, the forest floor released CH4 into the atmosphere (37 μg CH4 m‑2 soil area h‑1). Under low soil water content (0.37 ± 0.02 m3 m‑3), the flux rates from stems of birch and pine decreased but remained mostly positive (i.e. emissions), whereas forest floor reversed to sink for CH4 (-44 μg CH4 m‑2 h‑1). In contrast, spruce CH4 emissions increased with decreasing soil water content up to 0.55 μg CH4 m‑2 h‑1. In general, the emission rates of all the tree species decreased from September/October onwards. In the winter, the tree fluxes remained low, but slightly positive, and increased again in the spring. The CH4 fluxes were

  20. Measurements of aerosol chemical composition in boreal forest summer conditions

    NASA Astrophysics Data System (ADS)

    ńijälä, M.; Junninen, H.; Ehn, M.; Petäjä, T.; Vogel, A.; Hoffmann, T.; Corrigan, A.; Russell, L.; Makkonen, U.; Virkkula, A.; Mäntykenttä, J.; Kulmala, M.; Worsnop, D.

    2012-04-01

    Boreal forests are an important biome, covering vast areas of the northern hemisphere and affecting the global climate change via various feedbacks [1]. Despite having relatively few anthropogenic primary aerosol sources, they always contain a non-negligible aerosol population [2]. This study describes aerosol chemical composition measurements using Aerodyne Aerosol Mass Spectrometer (C-ToF AMS, [3]), carried out at a boreal forest area in Hyytiälä, Southern Finland. The site, Helsinki University SMEAR II measurement station [4], is situated at a homogeneous Scots pine (Pinus sylvestris) forest stand. In addition to the station's permanent aerosol, gas phase and meteorological instruments, during the HUMPPA (Hyytiälä United Measurements of Photochemistry and Particles in Air) campaign in July 2010, a very comprehensive set of atmospheric chemistry measurement instrumentation was provided by the Max Planck Institute for chemistry, Johannes Gutenberg-University, University of California and the Finnish Meteorological institute. In this study aerosol chemical composition measurements from the campaign are presented. The dominant aerosol chemical species during the campaign were the organics, although periods with elevated amounts of particulate sulfates were also seen. The overall AMS measured particle mass concentrations varied from near zero to 27 μg/m observed during a forest fire smoke episode. The AMS measured aerosol mass loadings were found to agree well with DMPS derived mass concentrations (r2=0.998). The AMS data was also compared with three other aerosol instruments. The Marga instrument [5] was used to provide a quantitative semi-online measurement of inorganic chemical compounds in particle phase. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed on daily filter samples, enabling the identification and quantification of organic aerosol subspecies. Finally an Atmospheric Pressure Chemical Ionization Ion Trap Mass Spectrometer (APCI

  1. Spectral reflectance patterns and temporal dynamics of common understory types in hemi-boreal forests in Järvselja, Estonia

    NASA Astrophysics Data System (ADS)

    Nikopensius, Maris; Raabe, Kairi; Pisek, Jan

    2014-05-01

    The knowledge about spectral properties and seasonal dynamics of understory layers in boreal forests currently holds several gaps. This introduces severe uncertainties while modelling the carbon balance of this ecosystem, which is expected to be prone to major shifts with climate change in the future. In this work the seasonal reflectance dynamics in European hemi-boreal forests are studied. The data for this study was collected at Järvselja Training and Experimental Forestry District (Estonia, 27.26°E 58.30°N). Measurements were taken in three different stands. The silver birch (Betula Pendula Roth) stand grows on typical brown gley-soil and its understory vegetation is dominated by a mixture of several grass species. The Scots pine (Pinus sylvestris) stand grows on a bog with understory vegetation composed of sparse labrador tea, cotton grass, and a continuous Sphagnum moss layer. The third stand, Norway spruce (Picea abies), grows on a Gleyi Ferric Podzol site with understory vegetation either partially missing or consisting of mosses such as Hylocomium splendens or Pleurozium schreberi [1]. The sampling design was similar to the study by Rautiainen et al. [3] in northern European boreal forests. At each study site, a 100 m long permanent transect was marked with flags. In addition, four intensive study plots (1 m × 1 m) were marked next to the transects at 20 m intervals. The field campaign lasted from May to September 2013. For each site the fractional cover of understory and understory spectra were estimated ten times i.e. every 2 to 3 weeks. Results from Järvselja forest were compared with the seasonal profiles from boreal forests in Hyytiälä, Finland [2]. References [1] A. Kuusk, M. Lang, J. Kuusk, T. Lükk, T. Nilson, M. Mõttus, M. Rautiainen, and A. Eenmäe, "Database of optical and structural data for validation of radiative transfer models", Technical Report, September 2009 [2] M. Rautiainen, M. Mõttus, J. Heiskanen, A. Akujärvi, T. Majasalmi

  2. The Snow Must Go On: Ground Ice Encasement, Snow Compaction and Absence of Snow Differently Cause Soil Hypoxia, CO2 Accumulation and Tree Seedling Damage in Boreal Forest.

    PubMed

    Martz, Françoise; Vuosku, Jaana; Ovaskainen, Anu; Stark, Sari; Rautio, Pasi

    2016-01-01

    At high latitudes, the climate has warmed at twice the rate of the global average with most changes observed in autumn, winter and spring. Increasing winter temperatures and wide temperature fluctuations are leading to more frequent rain-on-snow events and freeze-thaw cycles causing snow compaction and formation of ice layers in the snowpack, thus creating ice encasement (IE). By decreasing the snowpack insulation capacity and restricting soil-atmosphere gas exchange, modification of the snow properties may lead to colder soil but also to hypoxia and accumulation of trace gases in the subnivean environment. To test the effects of these overwintering conditions changes on plant winter survival and growth, we established a snow manipulation experiment in a coniferous forest in Northern Finland with Norway spruce and Scots pine seedlings. In addition to ambient conditions and prevention of IE, we applied three snow manipulation levels: IE created by artificial rain-on-snow events, snow compaction and complete snow removal. Snow removal led to deeper soil frost during winter, but no clear effect of IE or snow compaction done in early winter was observed on soil temperature. Hypoxia and accumulation of CO2 were highest in the IE plots but, more importantly, the duration of CO2 concentration above 5% was 17 days in IE plots compared to 0 days in ambient plots. IE was the most damaging winter condition for both species, decreasing the proportion of healthy seedlings by 47% for spruce and 76% for pine compared to ambient conditions. Seedlings in all three treatments tended to grow less than seedlings in ambient conditions but only IE had a significant effect on spruce growth. Our results demonstrate a negative impact of winter climate change on boreal forest regeneration and productivity. Changing snow conditions may thus partially mitigate the positive effect of increasing growing season temperatures on boreal forest productivity. PMID:27254100

  3. The Snow Must Go On: Ground Ice Encasement, Snow Compaction and Absence of Snow Differently Cause Soil Hypoxia, CO2 Accumulation and Tree Seedling Damage in Boreal Forest

    PubMed Central

    Vuosku, Jaana; Ovaskainen, Anu; Stark, Sari; Rautio, Pasi

    2016-01-01

    At high latitudes, the climate has warmed at twice the rate of the global average with most changes observed in autumn, winter and spring. Increasing winter temperatures and wide temperature fluctuations are leading to more frequent rain-on-snow events and freeze-thaw cycles causing snow compaction and formation of ice layers in the snowpack, thus creating ice encasement (IE). By decreasing the snowpack insulation capacity and restricting soil-atmosphere gas exchange, modification of the snow properties may lead to colder soil but also to hypoxia and accumulation of trace gases in the subnivean environment. To test the effects of these overwintering conditions changes on plant winter survival and growth, we established a snow manipulation experiment in a coniferous forest in Northern Finland with Norway spruce and Scots pine seedlings. In addition to ambient conditions and prevention of IE, we applied three snow manipulation levels: IE created by artificial rain-on-snow events, snow compaction and complete snow removal. Snow removal led to deeper soil frost during winter, but no clear effect of IE or snow compaction done in early winter was observed on soil temperature. Hypoxia and accumulation of CO2 were highest in the IE plots but, more importantly, the duration of CO2 concentration above 5% was 17 days in IE plots compared to 0 days in ambient plots. IE was the most damaging winter condition for both species, decreasing the proportion of healthy seedlings by 47% for spruce and 76% for pine compared to ambient conditions. Seedlings in all three treatments tended to grow less than seedlings in ambient conditions but only IE had a significant effect on spruce growth. Our results demonstrate a negative impact of winter climate change on boreal forest regeneration and productivity. Changing snow conditions may thus partially mitigate the positive effect of increasing growing season temperatures on boreal forest productivity. PMID:27254100

  4. Peatland pines as a proxy for water table fluctuations: disentangling tree growth, hydrology and possible human influence.

    PubMed

    Smiljanić, Marko; Seo, Jeong-Wook; Läänelaid, Alar; van der Maaten-Theunissen, Marieke; Stajić, Branko; Wilmking, Martin

    2014-12-01

    Dendrochronological investigations of Scots pine (Pinus sylvestris L.) growing on Männikjärve peatland in central Estonia showed that annual tree growth of peatland pines can be used as a proxy for past variations of water table levels. Reconstruction of past water table levels can help us to better understand the dynamics of various ecological processes in peatlands, e.g. the formation of vegetation patterns or carbon and nitrogen cycling. Männikjärve bog has one of the longest water table records in the boreal zone, continuously monitored since 1956. Common uncertainties encountered while working with peatland trees (e.g. narrow, missing and wedging rings) were in our case exacerbated with difficulties related to the instability of the relationship between tree growth and peatland environment. We hypothesized that the instable relationship was mainly due to a significant change of the limiting factor, i.e. the rise of the water table level due to human activity. To test our hypothesis we had to use several novel methods of tree-ring chronology analysis as well as to test explicitly whether undetected missing rings biased our results. Since the hypothesis that the instable relationship between tree growth and environment was caused by a change in limiting factor could not be rejected, we proceeded to find possible significant changes of past water table levels using structural analysis of the tree-ring chronologies. Our main conclusions were that peatland pines can be proxies to water table levels and that there were several shifting periods of high and low water table levels in the past 200 years. PMID:25217744

  5. N cycling and the composition of terpenes and tannins in boreal forest soils: Effects of logging residues

    NASA Astrophysics Data System (ADS)

    Smolander, Aino; Kitunen, Veikko; Kukkola, Mikko; Tamminen, Pekka

    2014-05-01

    There is increasing evidence available that certain terpenes and tannins may mediate substantial changes in nitrogen cycling processes in boreal forest soils. Terpenes and tannins are two important groups of plant secondary metabolites: Terpenes are hydrocarbons having different number of isoprene-derived units and tannins are complex polyphenolic compounds able to interact with proteins. Logging residues, consisting of fresh tree tops and branches with needles contain large amounts of terpenes and tannins. Currently there is increasing demand for forest biomass for bioenergy production. Therefore, harvesting of logging residues has become more common from both clear-cutting and thinning stands, instead of conventional stem-only harvest where logging residues are retained on the site. Our aim was to determine how logging residues affect soil N cycling processes in Scots pine and Norway spruce thinning stands in long-term, and how these processes are related to the composition of terpenes and tannins in the soil. Samples were taken from the humus layer of pine and spruce experiments which had been thinned 4-to-19 years before; in the thinning different amounts of logging residues had been distributed on the plots. Logging residues had only little effect on soil microbial biomass N or C. However, in several sites logging residues increased the rate of net N mineralization and the ratios net N mineralization/ C mineralization and net N mineralization/microbial biomass N, and these positive effects were very long-lasting. Logging residues also changed the composition of different terpenes and condensed tannins in soil. In general, with regard to the processes and ratios indicating N availability, stem-only harvest seems to be more favorable than whole-tree harvest. The results from long-term field experiments will be discussed in relation to the effects of different terpenes and tannins, observed in short-term laboratory experiments, on N cycling processes.

  6. Spatial and temporal patterns of solar-induced chlorophyll fluorescence from a Finnish boreal landscape: Comparisons from the ground up to space

    NASA Astrophysics Data System (ADS)

    Drolet, G.; Nichol, C. J.; Wade, T. J.; Porcar-Castell, A.; Nikinmaa, E.; Middleton, E.; Ong, L.; Vesala, T.; Levula, J.; Moncrieff, J. B.

    2010-12-01

    Remote sensing of the solar-induced chlorophyll fluorescence (F) by vegetation has the potential to provide important information about carbon uptake dynamics in terrestrial ecosystems. Because of the strong physiological link between F and the photosynthetic status, accurate and timely estimates of F over large areas could significantly improve the understanding and predictions of how terrestrial ecosystems respond to climate change. In the past few decades, a number of different techniques and models aimed at retrieving F from remotely sensed measurements of vegetation reflectance were developed and in this study, we took advantage of these new developments to look at the spatial and temporal patterns of F in boreal coniferous forests. The results we present here are part of a larger research project aimed at improving reflectance-based estimates of photosynthesis efficiency and carbon uptake using space-based observations of boreal vegetation. During the summer of 2010, we continuously measured Scots pine (Pinus sylvestris) canopy reflectance using a tower-based spectrometer system (USB-2000+, Ocean Optics, USA) and leaf-level fluorescence using an automated multi channel chlorophyll fluorescence system (MONI-PAM, Heinz Walz GmbH, Germany). These measurements allowed studying the temporal dynamics of canopy-level F and testing methods for extracting F from canopy reflectance. During an intensive airborne campaign in July 2010, we used the University of Edinburgh’s research aircraft equipped with a dual field-of-view spectrometer system (FieldSpec Pro, Analytical Spectral Devices, USA) to repeatedly measure vegetation hyperspectral reflectance over a large area of boreal forest which encompassed the forest canopy sampled by the tower-based system. Airborne- and tower-based estimates of F where correlated to enable studying the spatial and temporal patterns of chlorophyll fluorescence and photosynthetic status over a larger extent of this boreal landscape in

  7. Transcriptome resources and functional characterization of monoterpene synthases for two host species of the mountain pine beetle, lodgepole pine (Pinus contorta) and jack pine (Pinus banksiana)

    PubMed Central

    2013-01-01

    Background The mountain pine beetle (MPB, Dendroctonus ponderosae) epidemic has affected lodgepole pine (Pinus contorta) across an area of more than 18 million hectares of pine forests in western Canada, and is a threat to the boreal jack pine (Pinus banksiana) forest. Defence of pines against MPB and associated fungal pathogens, as well as other pests, involves oleoresin monoterpenes, which are biosynthesized by families of terpene synthases (TPSs). Volatile monoterpenes also serve as host recognition cues for MPB and as precursors for MPB pheromones. The genes responsible for terpene biosynthesis in jack pine and lodgepole pine were previously unknown. Results We report the generation and quality assessment of assembled transcriptome resources for lodgepole pine and jack pine using Sanger, Roche 454, and Illumina sequencing technologies. Assemblies revealed transcripts for approximately 20,000 - 30,000 genes from each species and assembly analyses led to the identification of candidate full-length prenyl transferase, TPS, and P450 genes of oleoresin biosynthesis. We cloned and functionally characterized, via expression of recombinant proteins in E. coli, nine different jack pine and eight different lodgepole pine mono-TPSs. The newly identified lodgepole pine and jack pine mono-TPSs include (+)-α-pinene synthases, (-)-α-pinene synthases, (-)-β-pinene synthases, (+)-3-carene synthases, and (-)-β-phellandrene synthases from each of the two species. Conclusion In the absence of genome sequences, transcriptome assemblies are important for defence gene discovery in lodgepole pine and jack pine, as demonstrated here for the terpenoid pathway genes. The product profiles of the functionally annotated mono-TPSs described here can account for the major monoterpene metabolites identified in lodgepole pine and jack pine. PMID:23679205

  8. Prevalence of ketonic carbonyl groups in submicron particles from a boreal forest in Hyytiälä, Finland during HUMPPA-COPEC 2010

    NASA Astrophysics Data System (ADS)

    Corrigan, A. L.; Russell, L. M.; Auld, J.; Song, W.; Williams, J.; Petdjd, T. T.

    2010-12-01

    The boreal forest in Hyytiälä, Finland, is a unique environment with respect to biogenic secondary organic aerosols. This site has hosted numerous field studies during the last 10 years, and nucleation events have frequently been observed above the canopy. Measurements of particle-phase organic functional groups and inorganic ions collected during the HUMPPA-COPEC10 campaign from July 12 - August 12, 2010, are compared with gas-phase biogenic and inorganic aerosol precursors to elucidate contributing factors on secondary organic aerosol formation in the Scots pine forest of Hyytiälä, Finland. Observed organic functional groups from Fourier transform infrared (FTIR) analysis of PM1 particles include alkane, carboxylic acid, organic hydroxyl, organonitrate, non-carboxylic acid carbonyl, and primary amine groups. Organic particles were also detected by aerosol mass spectrometry (AMS) and the two methods were shown to compare well. Organic particle composition is studied through a combination of factor analysis of organic functional groups (FTIR) and organic mass fragments (AMS).

  9. Scots in the Northern Fur Trade: A Middleman Minority Perspective.

    ERIC Educational Resources Information Center

    Zenner, Walter P.; Jarvenpa, Robert

    1980-01-01

    Explores the entrepreneurial role of Scots in the Canadian Northwest since the nineteenth century. Links entrepreneurship behavior with economic and social structural factors. Also discusses relations between Scots and local Indian groups. Attributes differences between Scots and other middleman minorities to the former's position in the powerful…

  10. Improving the modeling of the seasonal carbon cycle of the boreal forest with chlorophyll fluorescence measurements

    NASA Astrophysics Data System (ADS)

    Thum, Tea; Aalto, Tuula; Aurela, Mika; Laurila, Tuomas; Zaehle, Sönke

    2014-05-01

    The boreal ecosystems are characterized a very strong seasonal cycle and they are very sensitive to the climatic variables. The vegetation's deep wintertime dormancy requires a long recovery time during spring before the plants reach their full photosynthetic capacity. During this recovery time the plants are highly susceptible the night frosts. The transition period is different during spring and autumn for the evergreen plants. During spring there is plenty of light, but cold air temperatures inhibit the photosynthesis. The plants therefore experience to high stress levels, as they need to protect their photosynthetic apparatus from intense light. In autumn the air temperature and light level decrease more concurrently. To have a realistic presentation of the carbon cycle in boreal forests it is important to have these characteristics properly modeled, so that also the implications of changing seasonality under climate change can be more reliably predicted. In this study, we focus on the CO2 exchange of a Scots pine forest Sodankylä located in Finnish Lapland, 100 km north from the Arctic Circle. Micrometeorological flux measurements provide information about the exchanges of carbon, energy and water between atmosphere and vegetation. To complement these fluxes, we use dark-adapted chlorophyll fluorescence (CF) measurements, which is an optical measurement and tracks the development of the photosynthetic capacity. These two approaches combined together are very useful when we want to improve the modeling of the forest's CO2 exchange. We used two models that describe the photosynthesis with the biochemical model of Farquhar et al. The FMI-CANOPY is a canopy level model that is feasible to use in parameter estimation. We used the CF measurements of Fv/Fm, that is a measure of the maximum photosynthetic capacity, to include a seasonal development in the base rate of the maximum carboxylation rate (Vc(max)) in FMI-CANOPY. The simulation results matched the

  11. Molecular identification of Phytoplasmas infecting diseased pine trees in the UNESCO-protected Curonian Spit of Lithuania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although mainly known as pathogens that affect angiosperms, phytoplasmas have recently been detected in diseased coniferous plants. In 2008-2014, we observed, in the Curonian Spit of western Lithuania and in forests of southern Lithuania (Varena district), diseased trees of Scots pine (Pinus sylvest...

  12. Projected dynamics of abiotic risks in boreal forest ecosystems (SRES A1B, B1)

    NASA Astrophysics Data System (ADS)

    Panferov, O.; Ahrends, B.; Doering, C.; Sogachev, A.

    2009-04-01

    The ongoing climate change causes an increasing frequency of weather extremes (Leckebusch et al., 2008), which can result in wide area damage events (drought, windthrows/breaks) within boreal forest ecosystem. The damage effects, however, depend not only on the strength of a driving force itself (e.g. wind speed) but also on combinations of effecting agents and forest structure. Thus, the present study investigates the projected future developments of abiotic risks in different boreal forests during the 21st Century under conditions of SRES scenarios A1B and B1. Climate scenario data of coupled ECHAM5-MPIOM were downscaled by the regional climate model (CLM) to the spatial resolution of 0.2° x 0.2°, using daily time- steps. With these input data the small-scale modelling with coupled process based sub-models (Jansen et al., 2008) was carried out e.g. for Solling region, (Germany) calculating the water and energy balance of forest ecosystems with modified BROOK 90 (Ahrends et al., 2009) and wind loading on trees with 3D ABL model SCADIS (Panferov and Sogachev, 2008). Norway spruce and Scots pine of various ages were chosen as typical tree species for boreal forest ecosystems and cambisols, podzolic cambisols and stagnosols as typical soil types. The risks of drought and windthrow/breaks for a certain forest stand result from daily combinations of soil water characteristics, static and gust wind loads and soil texture. Damaged stands show higher vulnerability and thus - positive feedback to climate forcing (Vygodskaya et al., 2008). Therefore differences of microclimatological conditions in the remaining stand after changes in forest structure (Radler et al, 2008) were taken into account. Modell output was aggregated to 30-years periods and compared to "present conditions" of 1981-2010. The results show an increment of drought risks towards 2100 caused by changes in precipitation pattern and increase of mean air temperature, whereas the A1B scenario is

  13. Seasonality in a boreal forest ecosystem affects the use of soil temperature and moisture as predictors of soil CO2 efflux

    NASA Astrophysics Data System (ADS)

    Niinistö, S. M.; Kellomäki, S.; Silvola, J.

    2011-03-01

    Our objectives were to identify factors related to temporal variation of soil CO2 efflux in a boreal pine forest and to evaluate simple predictive models of temporal variation of soil CO2 efflux. Soil CO2 efflux was measured with a portable chamber in a Finnish Scots pine forest for three years, with a fourth year for model evaluation. Plot averages for soil CO2 efflux ranged from 0.04 to 0.90 g CO2 m-2 h-1 during the snow-free period, i.e. May-October, and from 0.04 to 0.13 g CO2 m-2 h-1 in winter. Soil temperature was a good predictor of soil CO2 efflux. A quadratic model of ln-transformed efflux explained 76-82% of the variation over the snow-free period. The results revealed strong seasonality: at a given soil temperature, soil CO2 efflux was higher later in the snow-free period than in spring and early summer. Regression coefficients for temperature (approximations of a Q10 value) of month-specific models decreased with increasing average soil temperatures. Efflux in July, the month of peak photosynthesis, showed no clear response to temperature or moisture. Inclusion of a seasonality index, degree days, improved the accuracy of temperature response models to predict efflux for the fourth year of measurements, which was not used in building of regression models. Underestimation during peak efflux (mid-July to late-August) remained uncorrected. The strong influence of the flux of photosynthates belowground and the importance of root respiration could explain the relative temperature insensitivity observed in July and together with seasonality of growth of root and root-associated mycorrhizal fungi could explain partial failure of models to predict magnitude of efflux in the peak season from mid-July to August. The effect of moisture early in the season was confounded by simultaneous advancement of the growing season and increase in temperature. In a dry year, however, the effect of drought was evident as soil CO2 efflux was some 30% smaller in September than in

  14. Variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle

    PubMed Central

    Taft, Spencer; Najar, Ahmed; Godbout, Julie; Bousquet, Jean; Erbilgin, Nadir

    2015-01-01

    The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and USA) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae), which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine's distribution, (−):(+)-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine's range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest. PMID:26042134

  15. Uptake and recycling of lead by boreal forest plants: Quantitative estimates from a site in northern Sweden

    NASA Astrophysics Data System (ADS)

    Klaminder, Jonatan; Bindler, Richard; Emteryd, Ove; Renberg, Ingemar

    2005-05-01

    As a consequence of deposition of atmospheric pollution, the lead concentration in the mor layer (the organic horizon) of remote boreal forest soils in Sweden is raised far above natural levels. How the mor will respond to decreased atmospheric pollution is not well known and is dependent on future deposition rates, downward migration losses and upward fluxes in the soil profile. Plants may contribute to the upward flux of lead by 'pumping' lead back to the mor surface through root uptake and subsequent litter fall. We use lead concentration and stable isotope ( 206Pb, 207Pb and 208Pb) measurements of forest vegetation to quantify plant uptake rates from the soil and direct from the atmosphere at two sites in northern Sweden; an undisturbed mature forest and a disturbed site with Scots pine ( Pinus sylvestris) growing on a recently exposed mineral soil (C-horizon) containing a minimum of atmospherically derived pollution lead. Analyses of forest mosses from a herbarium collection (spanning the last ˜100 yr) and soil matrix samples suggest that the atmospheric lead deposited on plants and soil has an average 206Pb/ 207Pb ratio of 1.15, while lead derived from local soil minerals has an average ratio of ˜1.47. Since the biomass of trees and field layer shrubs has an average 206Pb/ 207Pb ratio of ˜1.25, this indicates that 70% ± 10% of the inventory of 1 ± 0.8 mg Pb m -2 stored in plants in the mature forest originates from pollution. Needles, bark and apical stemwood of the pine growing on the disturbed soil, show lower 206Pb/ 207Pb ratios (as low as 1.21) than the roots and basal stemwood (having ratios > 1.36), which indicate that plants are able to incorporate lead directly from the atmosphere (˜50% of the total tree uptake). By partitioning the total uptake of lead into uptake from the atmosphere and different soil layers using an isotopic mixing model, we estimate that ˜0.03 ± 0.01, 0.02 ± 0.01 and 0.05 ± 0.01 mg Pb m -2 yr -1 (mean ± SD), is taken up

  16. AmeriFlux CA-Qfo Quebec - Eastern Boreal, Mature Black Spruce

    SciTech Connect

    Margolis, Hank A.

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site CA-Qfo Quebec - Eastern Boreal, Mature Black Spruce. Site Description - 49.69247° N / 74.34204° W, elevation of 387 mm, 90 - 100 yr old Black Spruce, Jack Pine, feather moss

  17. Greater carbon allocation to mycorrhizal fungi reduces tree nitrogen uptake in a boreal forest.

    PubMed

    Hasselquist, Niles J; Metcalfe, Daniel B; Inselsbacher, Erich; Stangl, Zsofia; Oren, Ram; Näsholm, Torgny; Högberg, Peter

    2016-04-01

    The central role that ectomycorrhizal (EM) symbioses play in the structure and function of boreal forests pivots around the common assumption that carbon (C) and nitrogen (N) are exchanged at rates favorable for plant growth. However, this may not always be the case. It has been hypothesized that the benefits mycorrhizal fungi convey to their host plants strongly depends upon the availability of C and N, both of which are rapidly changing as a result of intensified human land use and climate change. Using large-scale shading and N addition treatments, we assessed the independent and interactive effects of changes in C and N supply on the transfer of N in intact EM associations with -15 yr. old Scots pine trees. To assess the dynamics of N transfer in EM symbioses, we added trace amounts of highly enriched 5NO3(-) label to the EM-dominated mor-layer and followed the fate of the 15N label in tree foliage, fungal chitin on EM root tips, and EM sporocarps. Despite no change in leaf biomass, shading resulted in reduced tree C uptake, ca. 40% lower fungal biomass on EM root tips, and greater 15N label in tree foliage compared to unshaded control plots, where more 15N label was found in fungal biomass on EM colonized root tips. Short-term addition of N shifted the incorporation of 15N label from EM fungi to tree foliage, despite no significant changes in below-ground tree C allocation to EM fungi. Contrary to the common assumption that C and N are exchanged at rates favorable for plant growth, our results show for the first time that under N-limited conditions greater C allocation to EM fungi in the field results in reduced, not increased, N transfer to host trees. Moreover, given the ubiquitous nature of mycorrhizal symbioses, our results stress the need to incorporate mycorrhizal dynamics into process-based ecosystem models to better predict forest C and N cycles in light of global climate change. PMID:27220217

  18. Automatic determination of trunk diameter, crown base and height of scots pine (Pinus Sylvestris L.) Based on analysis of 3D point clouds gathered from multi-station terrestrial laser scanning. (Polish Title: Automatyczne okreslanie srednicy pnia, podstawy korony oraz wysokosci sosny zwyczajnej (Pinus Silvestris L.) Na podstawie analiz chmur punktow 3D pochodzacych z wielostanowiskowego naziemnego skanowania laserowego)

    NASA Astrophysics Data System (ADS)

    Ratajczak, M.; Wężyk, P.

    2015-12-01

    Rapid development of terrestrial laser scanning (TLS) in recent years resulted in its recognition and implementation in many industries, including forestry and nature conservation. The use of the 3D TLS point clouds in the process of inventory of trees and stands, as well as in the determination of their biometric features (trunk diameter, tree height, crown base, number of trunk shapes), trees and lumber size (volume of trees) is slowly becoming a practice. In addition to the measurement precision, the primary added value of TLS is the ability to automate the processing of the clouds of points 3D in the direction of the extraction of selected features of trees and stands. The paper presents the original software (GNOM) for the automatic measurement of selected features of trees, based on the cloud of points obtained by the ground laser scanner FARO. With the developed algorithms (GNOM), the location of tree trunks on the circular research surface was specified and the measurement was performed; the measurement covered the DBH (l: 1.3m), further diameters of tree trunks at different heights of the tree trunk, base of the tree crown and volume of the tree trunk (the selection measurement method), as well as the tree crown. Research works were performed in the territory of the Niepolomice Forest in an unmixed pine stand (Pinussylvestris L.) on the circular surface with a radius of 18 m, within which there were 16 pine trees (14 of them were cut down). It was characterized by a two-storey and even-aged construction (147 years old) and was devoid of undergrowth. Ground scanning was performed just before harvesting. The DBH of 16 pine trees was specified in a fully automatic way, using the algorithm GNOM with an accuracy of +2.1%, as compared to the reference measurement by the DBH measurement device. The medium, absolute measurement error in the cloud of points - using semi-automatic methods "PIXEL" (between points) and PIPE (fitting the cylinder) in the FARO Scene 5.x

  19. Penicillium expansum volatiles reduce pine weevil attraction to host plants.

    PubMed

    Azeem, Muhammad; Rajarao, Gunaratna Kuttuva; Nordenhem, Henrik; Nordlander, Göran; Borg-Karlson, Anna Karin

    2013-01-01

    The pine weevil Hylobius abietis (L.) is a severe pest of conifer seedlings in reforested areas of Europe and Asia. To identify minimally toxic and ecologically sustainable compounds for protecting newly planted seedlings, we evaluated the volatile metabolites produced by microbes isolated from H. abietis feces and frass. Female weevils deposit feces and chew bark at oviposition sites, presumably thus protecting eggs from feeding conspecifics. We hypothesize that microbes present in feces/frass are responsible for producing compounds that deter weevils. Here, we describe the isolation of a fungus from feces and frass of H. abietis and the biological activity of its volatile metabolites. The fungus was identified by morphological and molecular methods as Penicillium expansum Link ex. Thom. It was cultured on sterilized H. abietis frass medium in glass flasks, and volatiles were collected by SPME and analyzed by GC-MS. The major volatiles of the fungus were styrene and 3-methylanisole. The nutrient conditions for maximum production of styrene and 3-methylanisole were examined. Large quantities of styrene were produced when the fungus was cultured on grated pine bark with yeast extract. In a multi-choice arena test, styrene significantly reduced male and female pine weevils' attraction to cut pieces of Scots pine twigs, whereas 3-methylanisole only reduced male weevil attraction to pine twigs. These studies suggest that metabolites produced by microbes may be useful as compounds for controlling insects, and could serve as sustainable alternatives to synthetic insecticides. PMID:23297108

  20. Comparison of lodgepole and jack pine resin chemistry: implications for range expansion by the mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae)

    PubMed Central

    Pitt, Caitlin; Carroll, Allan L.; Lindgren, B. Staffan; Huber, Dezene P.W.

    2014-01-01

    The mountain pine beetle, Dendroctonus ponderosae, is a significant pest of lodgepole pine in British Columbia (BC), where it has recently reached an unprecedented outbreak level. Although it is native to western North America, the beetle can now be viewed as a native invasive because for the first time in recorded history it has begun to reproduce in native jack pine stands within the North American boreal forest. The ability of jack pine trees to defend themselves against mass attack and their suitability for brood success will play a major role in the success of this insect in a putatively new geographic range and host. Lodgepole and jack pine were sampled along a transect extending from the beetle’s historic range (central BC) to the newly invaded area east of the Rocky Mountains in north-central Alberta (AB) in Canada for constitutive phloem resin terpene levels. In addition, two populations of lodgepole pine (BC) and one population of jack pine (AB) were sampled for levels of induced phloem terpenes. Phloem resin terpenes were identified and quantified using gas chromatography. Significant differences were found in constitutive levels of terpenes between the two species of pine. Constitutive α-pinene levels – a precursor in the biosynthesis of components of the aggregation and antiaggregation pheromones of mountain pine beetle – were significantly higher in jack pine. However, lower constitutive levels of compounds known to be toxic to bark beetles, e.g., 3-carene, in jack pine suggests that this species could be poorly defended. Differences in wounding-induced responses for phloem accumulation of five major terpenes were found between the two populations of lodgepole pine and between lodgepole and jack pine. The mountain pine beetle will face a different constitutive and induced phloem resin terpene environment when locating and colonizing jack pine in its new geographic range, and this may play a significant role in the ability of the insect to

  1. Precision aspheric optics testing with SCOTS: a deflectometry approach

    NASA Astrophysics Data System (ADS)

    Su, Peng; Khreishi, Manal; Huang, Run; Su, Tianquan; Burge, James H.

    2013-04-01

    Absolute measurement with SCOTS/deflectometry is a calibration problem. We use a laser tracker to calibrate the test geometry. The performance id demonstrated with the initial measurement results from the Large Synoptic Survey Telescope tertiary mirror. Systematic errors from the camera are carefully controlled. Camera pupil imaging aberration is removed with an external aperture stop. Imaging aberration and other inherent errors are suppressed with a rotation test. Results show that the SCOTS can act as a large dynamic range, high precision, non-null test method for precision aspheric optics. The SCOTS test can achieve measurement accuracy comparable with the traditional interferometric testing.

  2. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species.

    PubMed

    Guada, Guillermo; Camarero, J Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die. PMID:27066053

  3. Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species

    PubMed Central

    Guada, Guillermo; Camarero, J. Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M. Navarro

    2016-01-01

    Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die. PMID:27066053

  4. Lichen conservation in heavily managed boreal forests.

    PubMed

    McMullin, Richard Troy; Thompson, Ian D; Newmaster, Steven G

    2013-10-01

    Lichens are an important component of the boreal forest, where they are long lived, tend to accumulate in older stands, and are a major food source for the threatened woodland caribou (Rangifer tarandus caribou). To be fully sustainable, silvicultural practices in the boreal forest must include the conservation of ecological integrity. Dominant forest management practices, however, have short-term negative effects on lichen diversity, particularly the application of herbicides. To better understand the long-term effects of forest management, we examined lichen regeneration in 35 mixed black spruce (Picea mariana) and jack pine (Pinus banksiana) forest stands across northern Ontario to determine recovery following logging and postharvest silvicultural practices. Our forest stands were 25-40 years old and had undergone 3 common sivilcultural treatments that included harvested and planted; harvested, planted, and treated with N-[phosphonomethyl] glycine (glyphosate); and harvested, planted, and treated with 2,4-dichlorophenoxyacetic acid (2,4-D). Forest stands with herbicide treatments had lower lichen biomass and higher beta and gamma diversity than planted stands that were not treated chemically or control stands. In northwestern Ontario, planted stands that were not treated chemically had significantly greater (p < 0.05) alpha diversity than stands treated with herbicides or control stands. Our results show that common silvicultural practices do not emulate natural disturbances caused by wildfires in the boreal forest for the lichen community. We suggest a reduction in the amount of chemical application be considered in areas where lichen biomass is likely to be high and where the recovery of woodland caribou is an objective. PMID:23869621

  5. Climatic dipoles drive two principal modes of North American boreal bird irruption

    PubMed Central

    Strong, Courtenay; Zuckerberg, Benjamin; Betancourt, Julio L.; Koenig, Walter D.

    2015-01-01

    Pine Siskins exemplify normally boreal seed-eating birds that can be sparse or absent across entire regions of North America in one year and then appear in large numbers the next. These dramatic avian “irruptions” are thought to stem from intermittent but broadly synchronous seed production (masting) in one year and meager seed crops in the next. A prevalent hypothesis is that widespread masting in the boreal forest at high latitudes is driven primarily by favorable climate during the two to three consecutive years required to initiate and mature seed crops in most conifers. Seed production is expensive for trees and is much reduced in the years following masting, driving boreal birds to search elsewhere for food and overwintering habitat. Despite this plausible logic, prior efforts to discover climate-irruption relationships have been inconclusive. Here, analysis of more than 2 million Pine Siskin observations from Project FeederWatch, a citizen science program, reveals two principal irruption modes (North-South and West-East), both of which are correlated with climate variability. The North-South irruption mode is, in part, influenced by winter harshness, but the predominant climate drivers of both modes manifest in the warm season as continental-scale pairs of oppositely signed precipitation and temperature anomalies (i.e., dipoles). The climate dipoles juxtapose favorable and unfavorable conditions for seed production and wintering habitat, motivating a push-pull paradigm to explain irruptions of Pine Siskins and possibly other boreal bird populations in North America. PMID:25964328

  6. Climatic dipoles drive two principal modes of North American boreal bird irruption.

    PubMed

    Strong, Courtenay; Zuckerberg, Benjamin; Betancourt, Julio L; Koenig, Walter D

    2015-05-26

    Pine Siskins exemplify normally boreal seed-eating birds that can be sparse or absent across entire regions of North America in one year and then appear in large numbers the next. These dramatic avian "irruptions" are thought to stem from intermittent but broadly synchronous seed production (masting) in one year and meager seed crops in the next. A prevalent hypothesis is that widespread masting in the boreal forest at high latitudes is driven primarily by favorable climate during the two to three consecutive years required to initiate and mature seed crops in most conifers. Seed production is expensive for trees and is much reduced in the years following masting, driving boreal birds to search elsewhere for food and overwintering habitat. Despite this plausible logic, prior efforts to discover climate-irruption relationships have been inconclusive. Here, analysis of more than 2 million Pine Siskin observations from Project FeederWatch, a citizen science program, reveals two principal irruption modes (North-South and West-East), both of which are correlated with climate variability. The North-South irruption mode is, in part, influenced by winter harshness, but the predominant climate drivers of both modes manifest in the warm season as continental-scale pairs of oppositely signed precipitation and temperature anomalies (i.e., dipoles). The climate dipoles juxtapose favorable and unfavorable conditions for seed production and wintering habitat, motivating a push-pull paradigm to explain irruptions of Pine Siskins and possibly other boreal bird populations in North America. PMID:25964328

  7. Controls over hydrocarbon emissions from boreal forest conifers

    SciTech Connect

    Lerdau, M.; Litvak, M.; Monson, R. |

    1995-06-01

    The emissions of monoterpenes and isoprene were measured from two species of conifers native to the boreal forest of Canada, jack pine, Pinus rigida, and black spruce, Picea Mariana. We examined the effects of phenology and needle age on the emissions of these compounds, and the variations in tissue concentrations of monoterpenes. We measured photosynthetic carbon uptake and hydrocarbon emissions at two sites in northern Saskatchewan under controlled light, temperatures, and CO{sub 2} concentrations, and analyzed carbon uptake rates using an infra-red gas analyzer and hydrocarbon emissions using a solid sorbent/thermal desorption system coupled to a gas chromatograph with a mass spectrometer. Our data indicate a strong effect of temperature and seasonality on emissions but only small effects of site conditions. These results suggest that regional models of hydrocarbon emissions from boreal forests should focus on temperature and phenology as the most important controlling variables.

  8. Disturbances (fire and grazing by reindeer) and soil methane fluxes -- case studies from the subarctic boreal forest of Finish Lapland.

    NASA Astrophysics Data System (ADS)

    Köster, Kajar; Köster, Egle; Berninger, Frank; Pumpanen, Jukka

    2016-04-01

    In aerobic, well-drained environments such as boreal upland forest soils, methane (CH4) is oxidized by microbes, resulting into the soils acting as a sink of atmospheric CH4. The emission of CH4 is controlled primarily by soil moisture and temperature, but also by the availability of organic carbon. Forest fires are one of the predominant natural disturbances in subarctic boreal forests that strongly influence soil moisture and soil temperature values and carbon dynamics of the soils. At the same time also the effect of reindeer (Rangifer tarandus L.) grazing on soil moisture and temperature regimes in the lichen-dominated Arctic ecosystems has been found to be considerable. By removing the lichen carpet and damaging the secondary vegetation mat, reindeer make patches of bare soil common, and these factors in combination with trampling allow for soil to warm up faster, reach higher temperatures, and reduce the soil moisture content. We studied the effect of reindeer grazing and forest fire on fluxes of CH4 in northern boreal subarctic Scots pine forest stands. The study areas are in eastern Lapland, Värriö Strict Nature Reserve, Finland (67° 46' N, 29° 35' E). The sites are situated north of the Arctic Circle, near to the northern timberline at an average of 300 m altitude. For studing the effect of fire we have established sample areas (with three replicate plots in each) in a chronosequence of 4 age classes (2 to 152 years since the last fire). The fire chronosequence consisted of four types of areas with different time since the last forest fire: i) 5 years, ii) 45 years, iii) 70 years and iv) 155 years after fire. For studing the effect of reindeer grazing (comparison of grazed and non-grazed areas) we have established the study areas (10 sample plots in total established in year 2013) along the borderline between Finland and Russia. The ungrazed area was excluded from the reindeer grazing already in 1918, to prevent the Finnish reindeer from going to the

  9. Long term implications of fire to soil C content and soil CO2 efflux in northern boreal forests

    NASA Astrophysics Data System (ADS)

    Koster, Kajar; Berninger, Frank; Pumpanen, Jukka

    2014-05-01

    Fire is the primary process which organizes the physical and biological attributes of the boreal biome and influences energy flows and biogeochemical cycles, particularly the carbon (C) cycle. Especially the soil organic matter pool in boreal forests is an important C storage with a long C turnover time, but fire frequencies that are expected to increase with changing climate, can change that. We compared the initial recovery of C pools and CO2 efflux following fire disturbance in Scots pine (Pinus sylvesteris) stands in the northern boreal forests, of eastern Lapland, Värriö Strict Nature Reserve, Finland (67°46' N, 29°35' E). The sites are situated north of the Arctic Circle, near to the northern timberline at an average of 300 m altitude. We have established 8 sample areas (with two replicate plots in each) in a chronosequence of 4 age classes (2 to 152 years since the last fire). The chronosequence consisted of four types of areas: (i) fire 2 years ago old areas, (ii) fire 42 years ago, (iii) fire around 60 years ago, (iv) fire 152years ago. The total C contents in the first 10 cm of the topsoil were highest on old areas (fire 150 years ago) and lowest on new areas (fire 2-40 years ago). The total C pool at the old site was 2411 g m-2. The area where the fire was 2 years ago had the lowest total C pools, 1474 g m-2 respectively. The lowest C pools were measured from area where the fire was 60 years ago, and from B horizon. The highest C pools were measured on old areas from top soil horizons (consisting of decomposing litter). When we compared the total C pools, the newly burned areas (areas where the fire was 2 - 40 years ago) formed one group (had similar values of total C) and old areas (areas where the fire was 60-150 years ago) formed another group with similar values. These results are also correlating to the soil respiration measurements. Soil CO2 efflux was lowest straight after the fire (0.042 mg CO2 m-2 s-1) and it reached a stable level of around

  10. 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