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Sample records for mature spruce forest

  1. Carbon and Nitrogen Pools and Fluxes in Adjacent Mature Norway Spruce and European Beech Forests

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    Filip Oulehle

    2016-11-01

    Full Text Available We compared two adjacent mature forest ecosystem types (spruce vs. beech to unravel the fate of assimilated carbon (C and the cycling of organic and inorganic nitrogen (N without the risk of the confounding influences of climatic and site differences when comparing different sites. The stock of C in biomass was higher (258 t·ha−1 in the older (150 years beech stand compared to the younger (80 years planted spruce stand (192 t·ha−1, whereas N biomass pools were comparable (1450 kg·ha−1. Significantly higher C and N soil pools were measured in the beech stand, both in forest floor and mineral soil. Cumulative annual CO2 soil efflux was similar among stands, i.e., 9.87 t·ha−1·year−1 of C in the spruce stand and 9.01 t·ha−1·year−1 in the beech stand. Soil temperature explained 78% (Q10 = 3.7 and 72% (Q10 = 4.2 of variability in CO2 soil efflux in the spruce and beech stand, respectively. However, the rather tight N cycle in the spruce stand prevented inorganic N losses, whereas losses were higher in the beech stand and were dominated by nitrate in the mineral soil. Our results highlighted the long-term consequences of forest management on C and N cycling.

  2. Composition and Elevation of Spruce Forests Affect Susceptibility to Bark Beetle Attacks: Implications for Forest Management

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    Massimo Faccoli

    2014-01-01

    Full Text Available The spruce bark beetle, Ips typographus (L. (Coleoptera: Curculionidae, Scolytinae, is one of the most destructive insects infesting spruce forests in Europe. Data concerning infestations of I. typographus occurring over the last 19 years (1994–2012 on the Southern Alps were analyzed in seven spruce forest types: (1 pure spruce plantations; (2 pure spruce reforestations; (3 pure spruce mountain forests; (4 pure spruce alpine forests; (5 spruce-conifer mixed forests; (6 spruce-broadleaf mixed forests; and (7 spruce-conifer-broadleaf mixed forests. The collected data included the amount of I. typographus damage and the location and composition of the infested forests. The results indicate that different forest types are differently susceptible to I. typographus. Plantations, reforestations and mountain spruce forests show mean damage and mean number of infestations higher than other forest types. Within pure spruce forests, alpine forests growing at high elevations (>1300 m suffer low damage. Furthermore, the mean number of infestation spots recorded annually in the different spruce forest types is negatively correlated with a Naturality Index value. The results suggest that forest composition and elevation are the main factors driving the risk of I. typographus damage. A new management strategy for some spruce forest types is needed, with a progressive reduction of pure spruce forests at low altitude and an increase of broadleaf composition.

  3. Organic halogens in spruce forest throughfall

    DEFF Research Database (Denmark)

    Öberg, G.; Johansen, C.; Grøn, C.

    1998-01-01

    . No relationship between the position of the collectors and the forest edge or dominating wind-direction was found, suggesting that dry deposition was not a major source. The concentration of organic halogens was related to that of organic carbon and decreased from the tree-trunk and outwards. In addition......, the concentrations were higher during the growing season than during the dormant season. This indicates that the major part of the organic carbon and organic halogens in spruce forest throughfall originates from canopy leachates or other internal sources. (C) 1998 Elsevier Science Ltd.......Deposition of dissolved organic halogens by throughfall was determined in a small spruce forest site in Denmark (56 degrees 28'N, 8 degrees 24'E). The mean annual deposition of dissolved organic halogens was 377 g ha(-1)yr(-1), and larger than the general deposition by precipitation...

  4. The vegetation of spruce forests in the Pinega State Reserve

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    Sergey Yu. Popov

    2016-08-01

    Full Text Available The Pinega Natural State Reserve is located in the Arkhangelsk Province in the northern taiga subzone. Spruce forests represent the dominant vegetation formation of its territory. The vegetation of this forest is classified, based on 192 phytosociological descriptions. It reveals 12 associations, which represent 7 groups of associations. Detailed characteristics of these syntaxa, including analysis of their biodiversity, are provided. The revealed syntaxa differ both in species composition and environmental conditions: moisture, nutrition, nitrogen availability and acidity. Most poor conditions in terms of mineral nutrition occupy sphagnous spruce forests and bilberry-dominated spruce forests, while under the richest conditions varioherbaceous, humidoherbaceous and nemoral-herbaceous spruce forests occur. The Pinega Reserve is the only locality, where the Piceetum rubo saxatilis-vacciniosum association occurs in the northern taiga subzone.

  5. Morphogenetic Litter Types of Bog Spruce Forests

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    T. T. Efremova

    2015-02-01

    Full Text Available For the first time the representation of moss litter morphogenetic structure of valley-riverside and streamside spruce forests was determined for the wetland intermountain area of Kuznetsk Alatau. In general, the litter of (green moss-hypnum spruce forest can be characterized as medium thickness (9–17 cm with high storage of organic matter (77–99 t/ha, which differs in neutral environmental conditions pH 6.8–7.0 and high percentage of ash 11–28 %. Formation litter types were identified, which depend on the content of mineral inclusions in organogenic substrate and the degree of its drainage. The differentiation of litter subhorizons was performed, visual diagnostic indicators of fermentative layers were characterized, and additional (indexes to indicate their specificity were developed. Peat- and peaty-fermentative, humified-fermentative and (black mold humus-fermentative layers were selected. Peat- and peaty-fermentative layers are characterized by content of platy peat macroaggregates of coarse vegetable composition, the presence of abundant fungal mycelium and soil animals are the primary decomposers – myriopoda, gastropoda mollusks. Humified-fermentative layers are identified by including the newly formed amorphous humus-like substances, nutty-granular structural parts of humus nature and soil animals’ humificators – enchytraeids and earthworms. (Black mold humus-fermentative layers are diagnosed by indicators with similar humified-fermentative, but differ from them in clay-humus composition of nutty-granular blue-grey parts. The nomenclature and classification of moss litter were developed on the basis of their diagnostic characteristics of fermentative layers – peat, peaty, reduced peaty, (black mold humus-peaty, reduced (black mold humus-peaty. Using the method of discriminant analysis, we revealed that the physical-chemical properties, mainly percentage of ash and decomposition degree of plant substrate, objectively

  6. Controls on moss evaporation in a boreal black spruce forest

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Arp, W.J.; Chapin, F.S.

    2004-01-01

    [1] Mosses are an important component of the boreal forest, but little is known about their contribution to ecosystem carbon, water, and energy exchange. We studied the role of mosses in boreal forest evapotranspiration by conducting two experiments in a black spruce forest in Fairbanks, Alaska.

  7. Fertilization Changes Chemical Defense in Needles of Mature Norway Spruce (Picea abies

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    Line Nybakken

    2018-06-01

    Full Text Available Nitrogen availability limits growth in most boreal forests. However, parts of the boreal zone receive significant levels of nitrogen deposition. At the same time, forests are fertilized to increase volume growth and carbon sequestration. No matter the source, increasing nitrogen in the boreal forest ecosystem will influence the resource situation for its primary producers, the plants, with possible implications for their defensive chemistry. In general, fertilization reduces phenolic compound concentrations in trees, but existing evidence mainly comes from studies on young plants. Given the role of the phenolic compounds in protection against herbivores and other forest pests, it is important to know if phenolics are reduced with fertilization also in mature trees. The evergreen Norway spruce is long-lived, and it is reasonable that defensive strategies could change from the juvenile to the reproductive and mature phases. In addition, as the needles are kept for several years, defense could also change with needle age. We sampled current and previous year needles from an N fertilization experiment in a Norway spruce forest landscape in south-central Norway to which N had been added annually for 13 years. We analyzed total nitrogen (N and carbon (C, as well as low-molecular phenolics and condensed tannins. Needles from fertilized trees had higher N than those from controls plots, and fertilization decreased concentrations of many flavonoids, as well as condensed tannins in current year needles. In previous year needles, some stilbenes and condensed tannins were higher in fertilized trees. In control trees, the total phenolic concentration was almost five times as high in previous year needles compared with those from the current year, and there were great compositional differences. Previous year needles contained highest concentrations of acetophenone and stilbenes, while in the current year needles the flavonoids, and especially coumaroyl

  8. Lessons from native spruce forests in Alaska: managing Sitka spruce plantations worldwide to benefit biodiversity and ecosystem services

    Science.gov (United States)

    Robert L. Deal; Paul Hennon; Richard O' Hanlon; David D' Amore

    2014-01-01

    There is increasing interest worldwide in managing forests to maintain or improve biodiversity, enhance ecosystem services and assure long-term sustainability of forest resources. An important goal of forest management is to increase stand diversity, provide wildlife habitat and improve forest species diversity. We synthesize results from natural spruce forests in...

  9. Liming effects on the chemical composition of the organic surface layer of a mature Norway spruce stand (Picea abies [L.] Karst.)

    NARCIS (Netherlands)

    Rosenberg, W.; Nierop, K.G.J.; Knicker, H.; Jager, de P.A.; Kreutzer, K.; Weiá, T.

    2003-01-01

    The application of lime in a mature Norway spruce (Picea abies [L.] Karst.) forest in southern Germany induced major changes in the activity of soil organisms and root growth. Since this may influence the chemical compostion of the soil organic matter (SOM) of the organic surface layer, its

  10. Short-term effects of forest disturbances on soil nematode communities in European mountain spruce forests.

    Science.gov (United States)

    Čerevková, A; Renčo, M; Cagáň, L

    2013-09-01

    The nematode communities in spruce forests were compared with the short-term effects of forest damage, caused by windstorm, wildfire and management practices of forest soils. Soil samples were collected in June and October from 2006 to 2008 in four different sites: (1) forest unaffected by the wind (REF); (2) storm-felled forest with salvaged timber (EXT); (3) modified forest affected by timber salvage (wood removal) and forest fire (FIR); and (4) storm-felled forest where timber had been left unsalvaged (NEX). Nematode analysis showed that the dominant species in all four investigated sites were Acrobeloides nanus and Eudorylaimus silvaticus. An increase of A. nanus (35% of the total nematode abundance) in the first year in the FIR site led to the highest total abundance of nematodes compared with other sites, where nematode abundance reached the same level in the third year. In the FIR site bacterial feeders appeared to be the most representative trophic group, although in the second and third year, after disturbance, the abundance of this trophic group gradually decreased. In the NEX site, the number of nematode species, population densities and Maturity Index were similar to that recorded for the FIR site. In EXT and NEX sites, the other dominant species was the plant parasitic nematode Paratylenchus microdorus. Analyses of nematodes extracted from different forest soil samples showed that the highest number of species and diversity index for species (H'spp) were in the REF site. Differences between the nematode fauna in REF and other localities were clearly depicted by cluster analysis. The greatest Structure Index and Enrichment Index values were also in REF. In the EXT site, the number of nematode species, their abundance, H'spp and Maturity Index were not significantly different from those recorded in the reference site.

  11. Fire severity unaffected by spruce beetle outbreak in spruce-fir forests in southwestern Colorado.

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    Andrus, Robert A; Veblen, Thomas T; Harvey, Brian J; Hart, Sarah J

    2016-04-01

    Recent large and severe outbreaks of native bark beetles have raised concern among the general public and land managers about potential for amplified fire activity in western North America. To date, the majority of studies examining bark beetle outbreaks and subsequent fire severity in the U.S. Rocky Mountains have focused on outbreaks of mountain pine beetle (MPB; Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests, but few studies, particularly field studies, have addressed the effects of the severity of spruce beetle (Dendroctonus rufipennis Kirby) infestation on subsequent fire severity in subalpine Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) forests. In Colorado, the annual area infested by spruce beetle outbreaks is rapidly rising, while MPB outbreaks are subsiding; therefore understanding this relationship is of growing importance. We collected extensive field data in subalpine forests in the eastern San Juan Mountains, southwestern Colorado, USA, to investigate whether a gray-stage (fire) spruce beetle infestation affected fire severity. Contrary to the expectation that bark beetle infestation alters subsequent fire severity, correlation and multivariate generalized linear regression analysis revealed no influence of pre-fire spruce beetle severity on nearly all field or remotely sensed measurements of fire severity. Findings were consistent across moderate and extreme burning conditions. In comparison to severity of the pre-fire beetle outbreak, we found that topography, pre-outbreak basal area, and weather conditions exerted a stronger effect on fire severity. Our finding that beetle infestation did not alter fire severity is consistent with previous retrospective studies examining fire activity following other bark beetle outbreaks and reiterates the overriding influence of climate that creates conditions conducive to large, high-severity fires in the subalpine zone of Colorado. Both bark beetle outbreaks and

  12. Mountain Norway spruce forests: Needle supply and its nutrient content

    Czech Academy of Sciences Publication Activity Database

    Kovářová, Marcela; Vacek, S.

    2003-01-01

    Roč. 49, - (2003), s. 327-332 ISSN 1212-4834 R&D Projects: GA AV ČR KSK6005114; GA ČR GA206/99/1416 Institutional research plan: CEZ:AV0Z6005908 Keywords : Šumava Mts. * Mountain Norway spruce forest * needle mass Subject RIV: EF - Botanics

  13. Long-term landscape changes in a subalpine spruce-fir forest in central Utah, USA

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    Jesse L. Morris1

    2015-12-01

    Full Text Available Background: In Western North America, increasing wildfire and outbreaks of native bark beetles have been mediated by warming climate conditions. Bioclimatic models forecast the loss of key high elevation species throughout the region. This study uses retrospective vegetation and fire history data to reconstruct the drivers of past disturbance and environmental change. Understanding the relationship among climate, antecedent disturbances, and the legacy effects of settlement-era logging can help identify the patterns and processes that create landscapes susceptible to bark beetle epidemics. Methods: Our analysis uses data from lake sediment cores, stand inventories, and historical records. Sediment cores were dated with radiometric techniques (14C and 210Pb/137Cs and subsampled for pollen and charcoal to maximize the temporal resolution during the historical period (1800 CE to present and to provide environmental baseline data (last 10,500 years. Pollen data for spruce were calibrated to carbon biomass (C t/ha using standard allometric equations and a transfer function. Charcoal samples were analyzed with statistical models to facilitate peak detection and determine fire recurrence intervals. Results: The Wasatch Plateau has been dominated by Engelmann spruce forests for the last ~10,500 years, with subalpine fir becoming more prominent since 6000 years ago. This landscape has experienced a dynamic fire regime, where burning events are more frequent and of higher magnitude during the last 3000 years. Two important disturbances have impacted Engelmann spruce in the historical period: 1 high-grade logging during the late 19th century; and (2 a high severity spruce beetle outbreak in the late 20th century that killed >90 % of mature spruce (>10 cm dbh. Conclusions: Our study shows that spruce-dominated forests in this region are resilient to a range of climate and disturbance regimes. Several lines of evidence suggest that 19th century logging

  14. Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst)

    International Nuclear Information System (INIS)

    Nikolova, Petia S.; Andersen, Christian P.; Blaschke, Helmut; Matyssek, Rainer; Haeberle, Karl-Heinz

    2010-01-01

    The effects of experimentally elevated O 3 on soil respiration rates, standing fine-root biomass, fine-root production and δ 13 C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O 3 under beech and spruce, and was related to O 3 -stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O 3 on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O 3 regime. δ 13 C signature of newly formed fine-roots was consistent with the differing g s of beech and spruce, and indicated stomatal limitation by O 3 in beech and by drought in spruce. Our study showed that drought can override the stimulating O 3 effects on fine-root dynamics and soil respiration in mature beech and spruce forests. - Drought has the capacity to override the stimulating ozone effect on soil respiration in adult European beech/Norway spruce forest.

  15. Performance of the Forest Vegetation Simulator in managed white spruce plantations influenced by eastern spruce budworm in northern Minnesota

    Science.gov (United States)

    Matthew B. Russell; Anthony W. D' Amato; Michael A. Albers; Christopher W. Woodall; Klaus J. Puettmann; Michael R. Saunders; Curtis L. VanderSchaaf

    2015-01-01

    Silvicultural strategies such as thinning may minimize productivity losses from a variety of forest disturbances, including forest insects. This study analyzed the 10-year postthinning response of stands and individual trees in thinned white spruce (Picea glauca [Moench] Voss) plantations in northern Minnesota, USA, with light to moderate defoliation...

  16. Using maximum entropy modeling to identify and prioritize red spruce forest habitat in West Virginia

    Science.gov (United States)

    Nathan R. Beane; James S. Rentch; Thomas M. Schuler

    2013-01-01

    Red spruce forests in West Virginia are found in island-like distributions at high elevations and provide essential habitat for the endangered Cheat Mountain salamander and the recently delisted Virginia northern flying squirrel. Therefore, it is important to identify restoration priorities of red spruce forests. Maximum entropy modeling was used to identify areas of...

  17. Nesting ecology of boreal forest birds following a massive outbreak of spruce beetles

    Science.gov (United States)

    Matsuoka, S.M.; Handel, C.M.

    2007-01-01

    We studied breeding dark-eyed juncos (Junco hyemalis), yellow-rumped warblers (Dendroica coronata), and spruce-nesting birds from 1997 to 1998 among forests with different levels of spruce (Picea spp.) mortality following an outbreak of spruce beetles (Dendroctonus rufipennis) in Alaska, USA. We identified species using live and beetle-killed spruce for nest sites and monitored nests to determine how the outbreak influenced avian habitat selection and reproduction. We tested predictions that 1) nesting success of ground-nesting juncos would increase with spruce mortality due to proliferation of understory vegetation available to conceal nests from predators, 2) nesting success of canopy-nesting warblers would decrease with spruce mortality due to fewer live spruce in which to conceal nests, and 3) both species would alter nest-site selection in response to disturbance. Juncos did not benefit from changes in understory vegetation; nesting success in highly disturbed stands (46%) was comparable to that in undisturbed habitats throughout their range. In stands with low spruce mortality, nesting success of juncos was low (5%) and corresponded with high densities of red squirrels (Tamiasciurus hudsonicus). Yellow-rumped warblers nested exclusively in spruce, but success did not vary with spruce mortality. As disturbance increased, nesting warblers switched from selecting forest patches with high densities of live white spruce (Picea glauca) to patches with beetle-killed spruce. Warblers also placed nests in large-diameter live or beetle-killed spruce, depending on which was more abundant in the stand, with no differences in nesting success. Five of the 12 other species of spruce-nesting birds also used beetle-killed spruce as nest sites. Because beetle-killed spruce can remain standing for >50 years, even highly disturbed stands provide an important breeding resource for boreal forest birds. We recommend that boreal forest managers preserve uncut blocks of infested

  18. Modelling long-term water yield effects of forest management in a Norway spruce forest

    Czech Academy of Sciences Publication Activity Database

    Yu, X.; Lamačová, A.; Duffy, Ch.; Krám, P.; Hruška, Jakub; White, T.; Bhatt, G.

    2015-01-01

    Roč. 60, č. 2 (2015), s. 174-191 ISSN 0262-6667 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : Lysina critical zone observatory * PIHM * Norway spruce * forest management Subject RIV: EH - Ecology, Behaviour Impact factor: 2.182, year: 2015

  19. Windstorms as mediator of soil nematode community changes: Evidence from European spruce forest

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    Renčo M.

    2017-03-01

    Full Text Available Nematode communities in a Norway spruce forest in High Tatra National Park, Slovakia were monitored for the period of several years (2006 and 2013. Unfortunately, in May 2014 natural windstorm damaged the forest. This disastrous event, together with preliminary obtained results allowed us to compare the direct impact of windstorm damage of forest habitat on soil nematode assemblages. The forest destruction by windstorm had a significant effect on the total nematode abundance, the abundance of omnivores and herbivores, as well as the nematode species diversity. The most dominant species, representing 55 % of the total nematode fauna, in the plot studied were Acrobeloides nanus followed by Malenchus exiguus, Filenchus vulgaris, Plectus communis, Plectus parvus and Tylencholaimus mirabilis. The abundance of bacterivorous signifi cantly increased after the windstorm, meanwhile the abundance of omnivores, fungivores, and herbivores ectoparasites and epidermal/root hair feeders showed an opposite trend. Of the evaluative indicators, Shannon species diversity (H’spp, maturity index (MI, maturity index 2-5 (MI2-5, sigma maturity index (ΣMI, enrichment index (EI and structure index (SI decreased significantly after windstorm. The EI and SI indexes characterized soil ecosystems before windstorm (2006 - 2013 as maturing with low or moderate disturbance, but soil ecosystems shortly after the windstorm (2014 were degraded and nutrient depleted. This also corresponded with graphical display of metabolic footprints characteristics of soil food web. Overall, the nematode communities differed significantly before and after forest damage. These results suggest the role of nematode communities as indicators of environment condition quality or its disruption.

  20. Formation of chloroform in spruce forest soil - results from laboratory incubation studies

    DEFF Research Database (Denmark)

    Haselmann, K.F.; Laturnus, F.; Svensmark, B.

    2000-01-01

    The release of chloroform, 1,1,1-trichloroethane, tetrachloromethane, trichloroethene and tetrachloroethene from an organic rich spruce forest soil was studied in laboratory incubation experiments by dynamic headspace analysis, thermodesorption and gas chromatography. Performance parameters...... are presented for the dynamic headspace system. For spruce forest soil, the results showed a significant increase in chloroform concentration in the headspace under aerobic conditions over a period of seven days, whereas the concentration of the other compounds remained fairly constant. A biogenic formation...

  1. Ecology and silviculture of the spruce-fir forests of eastern North America

    Science.gov (United States)

    Marinus. Westveld

    1953-01-01

    Using the climax forest as a guide to growing the species best suited to the climate and the site, the author offers a silvicultural system for managing the spruce-fir forests of eastern North America. Based on ecological principles, such silviculture is aimed to bring about forests that are inherently healthy and have a natural resistance to insects and disease.

  2. Using silviculture to influence carbon sequestration in southern Appalachian spruce-fir forests

    Science.gov (United States)

    Patrick T. Moore; R. Justin DeRose; James N. Long; Helga. van Miegroet

    2012-01-01

    Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled....

  3. Densities of breeding birds and changes in vegetation in an alaskan boreal forest following a massive disturbance by spruce beetles

    Science.gov (United States)

    Matsuoka, S.M.; Handel, C.M.; Ruthrauff, D.R.

    2001-01-01

    We examined bird and plant communities among forest stands with different levels of spruce mortality following a large outbreak of spruce beetles (Dendroctonus rufipennis (Kirby)) in the Copper River Basin, Alaska. Spruce beetles avoided stands with black spruce (Picea mariana) and selectively killed larger diameter white spruce (Picea glauca), thereby altering forest structure and increasing the dominance of black spruce in the region. Alders (Alnus sp.) and crowberry (Empetrum nigrum) were more abundant in areas with heavy spruce mortality, possibly a response to the death of overstory spruce. Grasses and herbaceous plants did not proliferate as has been recorded following outbreaks in more coastal Alaskan forests. Two species closely tied to coniferous habitats, the tree-nesting Ruby-crowned Kinglet (Regulus calendula) and the red squirrel (Tamiasciurus hudsonicus), a major nest predator, were less abundant in forest stands with high spruce mortality than in low-mortality stands. Understory-nesting birds as a group were more abundant in forest stands with high levels of spruce mortality, although the response of individual bird species to tree mortality was variable. Birds breeding in stands with high spruce mortality likely benefited reproductively from lower squirrel densities and a greater abundance of shrubs to conceal nests from predators.

  4. Space sequestration below ground in old-growth spruce-beech forests-signs for facilitation?

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    Bolte, Andreas; Kampf, Friederike; Hilbrig, Lutz

    2013-01-01

    Scientists are currently debating the effects of mixing tree species for the complementary resource acquisition in forest ecosystems. In four unmanaged old-growth spruce-beech forests in strict nature reserves in southern Sweden and northern Germany we assessed forest structure and fine rooting profiles and traits (≤2 mm) by fine root sampling and the analysis of fine root morphology and biomass. These studies were conducted in selected tree groups with four different interspecific competition perspectives: (1) spruce as a central tree, (2) spruce as competitor, (3) beech as a central tree, and (4) beech as competitor. Mean values of life fine root attributes like biomass (FRB), length (FRL), and root area index (RAI) were significantly lower for spruce than for beech in mixed stands. Vertical profiles of fine root attributes adjusted to one unit of basal area (BA) exhibited partial root system stratification when central beech is growing with spruce competitors. In this constellation, beech was able to raise its specific root length (SRL) and therefore soil exploration efficiency in the subsoil, while increasing root biomass partitioning into deeper soil layers. According to relative values of fine root attributes (rFRA), asymmetric below-ground competition was observed favoring beech over spruce, in particular when central beech trees are admixed with spruce competitors. We conclude that beech fine rooting is facilitated in the presence of spruce by lowering competitive pressure compared to intraspecific competition whereas the competitive pressure for spruce is increased by beech admixture. Our findings underline the need of spatially differentiated approaches to assess interspecific competition below ground. Single-tree approaches and simulations of below-ground competition are required to focus rather on microsites populated by tree specimens as the basic spatial study area.

  5. Space sequestration below ground in old-growth spruce-beech forests – signs for facilitation?

    Directory of Open Access Journals (Sweden)

    Andreas eBolte

    2013-08-01

    Full Text Available Scientists are currently debating the effects of mixing tree species for the complementary resource acquisition in forest ecosystems. In four unmanaged old-growth spruce-beech forests in strict nature reserves in southern Sweden and northern Germany we assessed forest structure and fine rooting profiles and traits (≤ 2 mm by fine root sampling and the analysis of fine root morphology and biomass. These studies were conducted in selected tree groups with four different interspecific competition perspectives: (1 spruce as a central tree, (2 spruce as competitor, (3 beech as a central tree, and (4 beech as competitor. Mean values of life fine root attributes like biomass (FRB, length (FRL, and root area index (RAI were significantly lower for spruce than for beech in mixed stands. Vertical profiles of fine root attributes adjusted to one unit of basal area (BA exhibited partial root system stratification when central beech is growing with spruce competitors. In this constellation, beech was able to raise its specific root length (SRL and therefore soil exploration efficiency in the subsoil, while increasing root biomass partitioning into deeper soil layers. According to relative values of fine root attributes (rFRA, asymmetric below-ground competition was observed favoring beech over spruce, in particular when central beech trees are admixed with spruce competitors. We conclude that beech fine rooting is facilitated in the presence of spruce by lowering competitive pressure compared to intraspecific competition whereas the competitive pressure for spruce is increased by beech admixture. Our findings underline the need of spatially differentiated approaches to assess interspecific competition below ground. Single-tree approaches and simulations of below-ground competition are required to focus rather on microsites populated by tree specimens as the basic spatial study area.

  6. Biological and Energy Productivity of Natural Spruce Forests in the Ukrainian Carpathians

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    R. D. Vasilishyn

    2014-10-01

    Full Text Available The modern practice of forestry production in Ukraine, which is in the process of implementing the conceptual changes in forest management and harmonization of its basic approaches to the basics of sustainable development, requires a significant expansion of the current regulatory and informational tools used to assess the ecological functions of forests. For this purpose, during the 2012–2014, as part of an international project GESAPU, models and tables of bioproductivity for forest tree species in Ukraine were completed. The article presents the results of modeling the dynamics of the conversion coefficients for the main components of phytomass of modal natural spruce forests of the Carpathian region of Ukraine based on information from 32 plots in the database of «Forest Phytomass of Ukraine». According to the state forest accounting of Ukraine as of January 1, 2011, the spruce forests in the Ukrainian Carpathians cover an area of 426.2 thousand ha, 45 % of which are spruce of natural origin. To evaluate the productivity of modal dynamics of pure and mixed spruce stands, the study developed models of the stock and overall productivity, derived by Bertalanffy growth function. On the basis of these models, normative reference tables of biological productivity of natural modal spruce forests of the Ukrainian Carpathians were developed. To successfully meet the challenges of evaluating the energy possibilities of forestry of Ukraine, the study used tables of energetic productivity of investigated stands. Built on the basis of the tables of bioproductivity, they reflect the dynamic processes of energy storage in the phytomass components and can be used in forest management to predict volumes of energetic woods.

  7. A 6-year-long manipulation with soil warming and canopy nitrogen additions does not affect xylem phenology and cell production of mature black spruce

    Directory of Open Access Journals (Sweden)

    Madjelia Cangre Ebou eDAO

    2015-11-01

    Full Text Available The predicted climate warming and increased atmospheric inorganic nitrogen deposition are expected to have dramatic impacts on plant growth. However, the extent of these effects and their interactions remains unclear for boreal forest trees. The aim of this experiment was to investigate the effects of increased soil temperature and nitrogen (N depositions on stem intra-annual growth of two mature stands of black spruce [Picea mariana (Mill. BSP] in Quebec, Canada. During 2008-2013, the soil around mature trees was warmed up by 4 °C with heating cables during the growing season and precipitations containing three times the current inorganic N concentration were added by frequent canopy applications. Xylem phenology and cell production were monitored weekly from April to October. The 6-year-long experiment performed in two sites at different altitude showed no substantial effect of warming and N-depositions on xylem phenological phases of cell enlargement, wall thickening and lignification. Cell production, in terms of number of tracheids along the radius, also did not differ significantly and followed the same patterns in control and treated trees. These findings allowed the hypothesis of a medium-term effect of soil warming and N depositions on the growth of mature black spruce to be rejected.

  8. Thermal Acclimation of Photosynthesis and Respiration Differ Across Mature Conifer Species in a Boreal Forest Peatland

    Science.gov (United States)

    Dusenge, M. E.; Stinziano, J. R.; Warren, J.; Ward, E. J.; Wullschleger, S.; Hanson, P. J.; Way, D.

    2017-12-01

    Boreal forests are often assumed to be temperature-limited, and warming is therefore expected to stimulate their carbon uptake. However, much of our information on the ability of boreal conifers to acclimate photosynthesis and respiration to rising temperatures comes from seedlings. We measured net CO2 assimilation rates (A) and dark respiration (R) at 25 °C (A25 and R25) and at prevailing growth temperatures (Ag and Rg) in mature Picea mariana (spruce) and Larix laricina (tamarack) exposed to ambient, +2.25, +4.5, +6.75 and +9 °C warming treatments in open top chambers in the field at the SPRUCE experiment (MN, USA). In spruce, A25 and Ag were similar across plots in May and June. In August, spruce in warmer treatments had higher A25, an effect that was offset by warmer leaf temperatures in the Ag data. In tamarack, A25 was stimulated by warming in both June and August, an effect that was mainly offset by higher leaf temperatures when Ag was assessed in June, while in August, Ag was still slightly higher in the warmest treatments (+6.75 and +9) compared to the ambient plots. In spruce, R25 was enhanced in warm-grown trees in May, but was similar across treatments in June and August, indicating little acclimation of R. Rg slightly increased with warming treatments across the season in spruce. In contrast, R in tamarack thermally acclimated, as R25 decreased with warming. But while this acclimation generated homeostatic Rg in June, Rg in August was still highest in the warmest treatments. Our work suggests that the capacity for thermal acclimation in both photosynthesis and respiration varies among boreal tree species, which may lead to shifts in the performance of these species as the climate warms.

  9. Phytosociological studies of the forests with sessile oak and Norway spruce from South-Eastern Transylvania

    Directory of Open Access Journals (Sweden)

    Adrian Indreica

    2011-02-01

    Full Text Available The forests with sessile oak (Quercus petraea and Norway spruce (Picea abies from south-eastern Transylvania represent a peculiar type of phytocenoses, rather unusual for the present-day vegetation of Romania’s territory. Aim of the study is to provide a detailed description of the vegetation and to identify the phytosociological and typological units to which it could belong. Beside this, stand structure and regeneration status of the main tree species are illustrated. The studied area is located around Carpathian intermountain depressions Braşov and Ciuc, where vegetation had a peculiar history and today sessile oak forests on high altitude exists, interfering with spruce forests. The hypothesis of the process naturalness is supported by vegetation history in the area, climate, stand structure and peculiarities of herb layer composition (the mixture of relic of both mountain-boreal origin and south-European origin, like Vaccinium vitis-idaea, Pyrola rotundifolia and respectively Potentilla micrantha, Lathyrus venetus respectively. Sintaxonomically, studied phytocenoses with sessile oak and spruce belong mainly to acidophilus oak forests (Luzulo luzuloidis-Quercetum petraeae, but some of them resemble oak-hornbeam forests (Carici pilosae-Carpinetum, indicating a more recent change in stand structure and suggesting that not the soil, but the climate is the driving force of succession. Regeneration of sessile oak is at least satisfactory, but the expansion of spruce in such stands could seriously restrict the survival of sessile oak. A new typological unit will be appropriate,for a better management of sessile oak forests with spruce admixture.

  10. Phytosociological studies of the forests with sessile oak and Norway spruce from South-Eastern Transylvania

    Directory of Open Access Journals (Sweden)

    Adrian Indreica

    2011-06-01

    Full Text Available The forests with sessile oak (Quercus petraea and Norway spruce (Picea abies from south-eastern Transylvania represent a peculiar type of phytocenoses, rather unusual for the present-day vegetation of Romania’s territory. Aim of the study is to provide a detailed description of the vegetation and to identify the phytosociological and typological units to which it could belong. Beside this, stand structure and regeneration status of the main tree species are illustrated. The studied area is located around Carpathian intermountain depressions Brasov and Ciuc, where vegetation had a peculiar history and today sessile oak forests on high altitude exists, interfering with spruce forests. The hypothesis of the process naturalness is supported by vegetation history in the area, climate, stand structure and peculiarities of herb layer composition (the mixture of relic of both mountain-boreal origin and south-European origin, like Vaccinium vitis-idaea, Pyrola rotundifolia and respectively Potentilla micrantha, Lathyrus venetus respectively. Sintaxonomically, studied phytocenoses with sessile oak and spruce belong mainly to acidophilus oak forests (Luzulo luzuloidis-Quercetum petraeae, but some of them resemble oak-hornbeam forests (Carici pilosae-Carpinetum, indicating a more recent change in stand structure and suggesting that not the soil, but the climate is the driving force of succession. Regeneration of sessile oak is at least satisfactory, but the expansion of spruce in such stands could seriously restrict the survival of sessile oak. A new typological unit will be appropriate, for a better management of sessile oak forests with spruce admixture.

  11. Soil and soil cover changes in spruce forests after final logging

    Directory of Open Access Journals (Sweden)

    E. M. Lapteva

    2015-10-01

    Full Text Available Soil cover transformation and changes of morphological and chemical properties of Albeluvisols in clear-cuttings of middle taiga spruce forests were studied. The observed changes in structure and properties of podzolic texturally-differentiated soils at cuttings of spruce forests in the middle taiga subzone do not cause their transition to any other soil type. Soil cover of secondary deciduous-coniferous forests which replace cut forests are characterized with a varied soil contour and a combination of the main type of podzolic soils under undisturbed spruce forests. The increased surface hydromorphism in cut areas causes formation of complicated sub-types of podzolic texturally differentiated soils (podzolic surface-gley soils with microprofile of podzol and enlarges their ratio (up to 35–38 % in soil cover structure. Temporary soil over-wetting at the initial (5–10 years stage of after-cutting self-restoring vegetation succession provides for soil gleyzation, improves yield and segregation of iron compounds, increases the migratory activity of humic substances. Low content and resources of total nitrogen in forest litters mark anthropogenic transformation processes of podzolic soils at this stage. Later (in 30–40 years after logging, soils in cut areas still retain signs of hydromorphism. Forest litters are denser, less acidic and thick with a low weight ratio of organic carbon as compared with Albeluvisols of undisturbed spruce forest. The upper mineral soil horizons under secondary deciduous-coniferous forests contain larger amounts of total iron, its mobile (oxalate-dissolvable components, and Fe-Mn-concretions.

  12. Foliar and soil chemistry at red spruce sites in the Monongahela National Forest

    Science.gov (United States)

    Stephanie J. Connolly

    2010-01-01

    In 2005, soil and foliar chemistry were sampled from 10 sites in the Monongahela National Forest which support red spruce. Soils were sampled from hand-dug pits, by horizon, from the O-horizon to bedrock or 152 cm, and each pit was described fully. Replicate, archived samples also were collected.

  13. Soil Warming: Consequences for Foliar Litter Decay in a Spruce-Fir Forest in Maine, USA

    Science.gov (United States)

    Lindsey E. Rustad; Ivan J. Fernandez

    1998-01-01

    Increased rates of litter decay due to projected global warming could substantially alter the balance between C assimilation and release in forest soils, with consequent feedbacks to climate change. This study was conducted to investigate the effects of soil warming on the decomposition of red spruce (Picea rubens Sarg.) and red maple (...

  14. Aerodynamic resistance of spruce forest stand in relation to roughness length and airflow

    Czech Academy of Sciences Publication Activity Database

    Hurtalová, T.; Matějka, F.; Rožnovský, J.; Janouš, Dalibor

    2003-01-01

    Roč. 33, č. 3 (2003), s. 147-160 ISSN 1335-2806 R&D Projects: GA ČR(CZ) GA526/03/1104 Keywords : aerodynamic resistance * spruce forest stand * roughness length Subject RIV: DG - Athmosphere Sciences, Meteorology

  15. Haloperoxidase-like activity in spruce forest soil. A source of volatile halogenated organic compounds?

    DEFF Research Database (Denmark)

    Laturnus, F.; Mehrtens, G.; Grøn, C.

    1995-01-01

    Haloperoxidase-like activity was monitored in samples from a podzol soil in an uncontaminated spruce forest at Klosterhede, Denmark. Activity for the oxidation of chloride and bromide was found. The pH optima for chlorination and bromination ranged between pH 2.5 and 4: Very high activity, up to 4...

  16. Soil saprotrophic micromycetes in Norway spruce forests in the Šumava National Park

    Czech Academy of Sciences Publication Activity Database

    Nováková, Alena

    2001-01-01

    Roč. 7, - (2001), s. 177-184 ISSN 1211-7420 R&D Projects: GA ČR GA206/99/1416 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil saprotrophic micromycetes * Norway spruce forest * bark beetle Subject RIV: EH - Ecology, Behaviour

  17. Leaf physiological responses of mature Norway Spruce trees exposed to elevated carbon dioxide and temperature

    Science.gov (United States)

    Lamba, Shubhangi; Uddling, Johan; Räntfors, Mats; Hall, Marianne; Wallin, Göran

    2014-05-01

    Leaf photosynthesis, respiration and stomatal conductance exert strong control over the exchange of carbon, water and energy between the terrestrial biosphere and the atmosphere. As such, leaf physiological responses to rising atmospheric CO2 concentration ([CO2]) and temperature have important implications for the global carbon cycle and rate of ongoing global warming, as well as for local and regional hydrology and evaporative cooling. It is therefore critical to improve the understanding of plant physiological responses to elevated [CO2] and temperature, in particular for boreal and tropical ecosystems. In order to do so, we examined physiological responses of mature boreal Norway spruce trees (ca 40-years old) exposed to elevated [CO2] and temperature inside whole-tree chambers at Flakaliden research site, Northern Sweden. The trees were exposed to a factorial combination of two levels of [CO2] (ambient and doubled) and temperature (ambient and +2.8 degree C in summer and +5.6 degree C in winter). Three replicates in each of the four treatments were used. It was found that photosynthesis was increased considerably in elevated [CO2], but was not affected by the warming treatment. The maximum rate of photosynthetic carboxylation was reduced in the combined elevated [CO2] and elevated temperature treatment, but not in single factor treatments. Elevated [CO2] also strongly increased the base rate of respiration and to a lesser extent reduced the temperature sensitivity (Q10 value) of respiration; responses which may be important for the carbon balance of these trees which have a large proportion of shaded foliage. Stomatal conductance at a given VPD was reduced by elevated temperature treatment, to a degree that mostly offset the higher vapour pressure deficit in warmed air with respect to transpiration. Elevated [CO2] did not affect stomatal conductance, and thus increased the ratio of leaf internal to external [CO2]. These results indicate that the large elevated

  18. The immigration and spread of spruce forest in Norway, traced by biostratigraphical studies and radiocarbon datings. A preliminary report

    International Nuclear Information System (INIS)

    Hafsten, U.

    1985-01-01

    Pollen-analytic studies and radiocarbon datings from 86 sites, mostly ombrotrophic peatbogs, situated within the Norwegian spruce domain, show that the occupation of the areas by spruce forest was the result of a protracted spread from cast, or northeast, to west and south, which started in late pre-Christian time and was completed mainly during the Middle Ages

  19. Establishment and growth of white spruce on a boreal forest floodplain: interactions between microclimate and mammalian herbivory

    Science.gov (United States)

    Amy C. Angell; Knut. Kielland

    2009-01-01

    White spruce (Picea glauca (Moench) Voss) is a dominant species in late-successional ecosystems along the Tanana River, interior Alaska, and the most important commercial timber species in these boreal floodplain forests. Whereas white spruce commonly seed in on young terraces in early primary succession, the species does not become a conspicuous...

  20. Occurrence of spruce bark beetles in forest stands at different levels of air pollution stress

    International Nuclear Information System (INIS)

    Grodzki, Wojciech; McManus, Michael; Knizek, Milos; Meshkova, Valentina; Mihalciuc, Vasile; Novotny, Julius; Turcani, Marek; Slobodyan, Yaroslav

    2004-01-01

    The spruce bark beetle, Ips typographus (L.) is the most serious pest of mature spruce stands, mainly Norway spruce, Picea abies (L.) Karst. throughout Eurasia. A complex of weather-related events and other environmental stresses are reported to predispose spruce stands to bark beetle attack and subsequent tree mortality; however the possible role of industrial pollution as a predisposing factor to attack by this species is poorly understood. The abundance and dynamics of I. typographus populations was evaluated in 60-80 year old Norway spruce stands occurring on 10x50 ha sites in five countries within the Carpathian range that were selected in proximity to established ozone measurement sites. Data were recorded on several parameters including the volume of infested trees, captures of adult beetles in pheromone traps, number of attacks, and the presence and relative abundance of associated bark beetle species. In several cases, stands adjacent to sites with higher ozone values were associated with higher bark beetle populations. The volume of sanitary cuttings, a reflection of tree mortality, and the mean daily capture of beetles in pheromone traps were significantly higher at sites where the O 3 level was higher. However, the mean infestation density on trees was higher in plots associated with lower O 3 levels. Captures of beetles in pheromone traps and infestation densities were higher in the zone above 800 m. However, none of the relationships was conclusive, suggesting that spruce bark beetle dynamics are driven by a complex interaction of biotic and abiotic factors and not by a single parameter such as air pollution. - Air pollution (ozone) can be one of predisposing factors that increases the susceptibility of mountain Norway spruce stands to attack by Ips typographus and associated bark beetle species

  1. Combined fluorescence, reflectance, and ground measurements of a stressed Norway spruce forest for forest damage assessment

    Science.gov (United States)

    Banninger, C.

    1991-01-01

    The detection and monitoring of stress and damage in forested areas is of utmost importance to forest managers for planning purposes. Remote sensing are the most suitable means to obtain this information. This requires that remote sensing data employed in a forest survey be properly chosen and utilized for their ability to measure canopy spectral features directly related to key tree and canopy properties that are indicators of forest health and vitality. Plant reflectance in the visible to short wave IR regions (400 to 2500 nm) provides information on its biochemical, biophysical, and morphological make up, whereas plant fluorescence in the 400 to 750 nm region is more indicative of the capacity and functioning of its photosynthetic apparatus. A measure of both these spectral properties can be used to provide an accurate assessment of stress and damage within the forest canopy. Foliar chlorophyll and nitrogen are essential biochemical constituents required for the proper functioning and maintenance of a plant's biological processes. Chlorophyll-a is the prime reactive center for photosynthesis, by which a plant converts CO2 and H2O into necessary plant products. Nitrogen forms an important component of the amino-acids, enzymes, proteins, alkaloids, and cyanogenic compounds that make up a plant, including its pigments. Both chlorophyll and nitrogen have characteristic absorption features in the visible to short wave IR region. By measuring the wavelength position and depth of these features and the fluorescence response of the foliage, the health and vitality of a canopy can be ascertained. Examples for a stressed Norway spruce forest in south-eastern Austria are presented.

  2. Structure and productivity of mixed spruce and fir forests on Mt. Kopaonik

    Directory of Open Access Journals (Sweden)

    Šljukić Biljana

    2017-01-01

    Full Text Available The subject of this research are mixed forests of spruce and fir in the area of NP Kopaonik, which belong to the community of spruce and fir - Abieti-Piceetum abietis Mišić et Popović, 1978. The basis for the study of the structural development and production potential of these forests are data from 12 sample plots, with the average size of 0.18 ha. In terms of coenoecological affiliation all the sample plots belong to the group of ecological units - forests of spruce and fir (Abieti-Piceetum abietis, Mišić et Popović, 1978 on acid brown and brown podzolic soils, which are differentiated into 5 ecological units: Abieti-Piceetum abietis oxalidetosum on brown podzolic soil, Abieti-Piceetum abietis oxalidetosum on acid brown soil, Abieti-Piceetum abietis vaccinietosum on brown podzolic soil, Abieti-Piceetum abietis typicum on brown podzolic soil and Abieti-Piceetum abietis Dr.ymetosum on brown pozolic soil. In structural terms, these forests are characterized by very diverse structural forms, ranging from the structure of even-aged stands to typical multi-storey, unevenaged-aged stands. The form of cumulative curves of tree distribution is in most cases determined by spruce as the dominant species. At the same time, thin and medium-thick trees dominate, while the presence of stems with large dimensions is minimal. The average volume of these forestse is 777 m3•ha-1, with a mixture ratio of 0.7: 0.3 in favor of spruce. The average value of the current volume increment is 14 m3•ha-1, with a 68% share of spruce and 32% of fir. The percentage of increment ranges from 1.6% to 2.5% in all sample plots and is somewhat higher for fir. The site potential, stand characteristics and relations among the tree species have resulted in structural complexity, high productivity and ecological stability of these forests. Therefore, future forest management should avoid radical measures and procedures that would violate the established relationships and

  3. Experimental versus modelled water use in mature Norway spruce (Picea abies exposed to elevated CO2

    Directory of Open Access Journals (Sweden)

    Sebastian eLeuzinger

    2012-10-01

    Full Text Available Rising levels of atmospheric CO2 have often been reported to reduce plant water use. Such behaviour is also predicted by standard equations relating photosynthesis, stomatal conductance, and atmospheric CO2 concentration, which form the core of global dynamic vegetation models (DGVMs. Here, we provide first results from a free air CO2 enrichment (FACE experiment with naturally growing, mature (35 m Picea abies (L. (Norway spruce and compare them to simulations by the DGVM LPJ-GUESS. We monitored sap flow, stem water deficit, stomatal conductance, leaf water potential and soil moisture in five 35-40 m tall CO2-treated (550 ppm trees over two seasons. Using LPJ-GUESS, we simulated this experiment using climate data from a nearby weather station. While the model predicted a stable reduction of transpiration of between 9 and 18 % (at concentrations of 550-700ppm atmospheric CO2, the combined evidence from various methods characterising water use in our experimental trees suggest no changes in response to future CO2 concentrations. The discrepancy between the modelled and the experimental results may be a scaling issue: while dynamic vegetation models correctly predict leaf-level responses, they may not sufficiently account for the processes involved at the canopy and ecosystem scale, which could mitigate the first-order stomatal response.

  4. A comparison of structural characteristics and ecological factors between forest reserves and managed silver fir - Norway spruce forests in Slovenia

    International Nuclear Information System (INIS)

    Marinšek, A.; Diaci, J.

    2011-01-01

    In order to examine ecological, floristic and structural differences between the forest stands of managed and unmanaged silver fir - Norway spruce forests (Bazzanio trilobatae-Abietetum albae), twelve sample plots (25x25 m) were established in forest reserves and managed forests. Within the plots, subplots and microplots we conducted phytosociological and pedological surveys, analyses of the stand structure, natural regeneration and estimation of solar radiation. We determined that there are no significant differences in floristic composition and ecological factors between managed forest and forest reserve stands. The only variables that were significantly different were the solar radiation variables (ISF; TSF; DSF), vertical structure (cover indexes (CI)) and stand basal area. Small differences in the composition and the structure of the vegetation indicate that, as far as ecosystematic changes are concerned, managing these forests is not as significant as the soil conditions. Solar radiation had a major influence on natural regeneration. Indirect solar radiation seemed to be more important than direct solar radiation. We found a statistically significant positive correlation between silver fir and Norway spruce regeneration and indirect solar radiation and confirmed that the management of light is a significant factor in the management of regeneration. Another trend that was detected was an increase in the number of beech, which will have quite a large proportion in the upper tree layer of the next generation, especially in forest reserves

  5. Utilization of hyperspectral image optical indices to assess the Norway spruce forest health status

    Czech Academy of Sciences Publication Activity Database

    Mišurec, J.; Kopáčková, V.; Lhotáková, Z.; Hanuš, Jan; Weyermann, J.; Entcheva-Campbel, P.; Albrechtová, J.

    2012-01-01

    Roč. 6, JUN 2012 (2012), 63545-1-63545-25 ISSN 1931-3195 R&D Projects: GA ČR GA205/09/1989 Institutional research plan: CEZ:AV0Z60870520 Keywords : chlorophyll * optical indices * Norway spruce * continuum removal * HyMap * actual physiological status * Sokolov basin * forest management Subject RIV: CE - Biochemistry Impact factor: 0.876, year: 2012

  6. Management intensity affects traits of soil microarthropod community in montane spruce forest

    Czech Academy of Sciences Publication Activity Database

    Farská, Jitka; Prejzková, Kristýna; Rusek, Josef

    2014-01-01

    Roč. 75, March (2014), s. 71-79 ISSN 0929-1393 R&D Projects: GA ČR GA526/03/1259; GA ČR GAP504/12/1218; GA MŠk LC06066 Grant - others:GAJU(CZ) 143/2010/P Institutional support: RVO:60077344 Keywords : Oribatida * Collembola * spruce forest * trait * management intensity Subject RIV: EH - Ecology, Behaviour Impact factor: 2.644, year: 2014

  7. Ozone flux over a Norway spruce forest and correlation with net ecosystem production

    International Nuclear Information System (INIS)

    Zapletal, Milos; Cudlin, Pavel; Chroust, Petr; Urban, Otmar; Pokorny, Radek; Edwards-Jonasova, Magda; Czerny, Radek; Janous, Dalibor; Taufarova, Klara; Vecera, Zbynek; Mikuska, Pavel; Paoletti, Elena

    2011-01-01

    Daily ozone deposition flux to a Norway spruce forest in Czech Republic was measured using the gradient method in July and August 2008. Results were in good agreement with a deposition flux model. The mean daily stomatal uptake of ozone was around 47% of total deposition. Average deposition velocity was 0.39 cm s -1 and 0.36 cm s -1 by the gradient method and the deposition model, respectively. Measured and modelled non-stomatal uptake was around 0.2 cm s -1 . In addition, net ecosystem production (NEP) was measured by using Eddy Covariance and correlations with O 3 concentrations at 15 m a.g.l., total deposition and stomatal uptake were tested. Total deposition and stomatal uptake of ozone significantly decreased NEP, especially by high intensities of solar radiation. - Highlights: → We estimate ozone deposition flux to a Norway spruce forest using the gradient method and model. → The mean stomatal uptake of ozone is approximately 47% of the total deposition. → We measure net ecosystem production (NEP) using Eddy Covariance. → We test whether elevated total deposition and stomatal uptake of O 3 imply a reduction of NEP. → Deposition and stomatal uptake of O 3 decrease NEP, especially by high intensities of solar radiation. - Net ecosystem production of a Norway spruce forest decreases with increasing deposition and stomatal uptake of ozone.

  8. Tradeoffs between hydraulic and mechanical stress responses of mature Norway spruce trunk wood.

    Science.gov (United States)

    Rosner, Sabine; Klein, Andrea; Müller, Ulrich; Karlsson, Bo

    2008-08-01

    We tested the effects of growth characteristics and basic density on hydraulic and mechanical properties of mature Norway spruce (Picea abies (L.) Karst.) wood from six 24-year-old clones, grown on two sites in southern Sweden differing in water availability. Hydraulic parameters assessed were specific hydraulic conductivity at full saturation (ks100) and vulnerability to cavitation (Psi50), mechanical parameters included bending strength (sigma b), modulus of elasticity (MOE), compression strength (sigma a) and Young's modulus (E). Basic density, diameter at breast height, tree height, and hydraulic and mechanical parameters varied considerably among clones. Clonal means of hydraulic and mechanical properties were strongly related to basic density and to growth parameters across sites, especially to diameter at breast height. Compared with stem wood of slower growing clones, stem wood of rapidly growing clones had significantly lower basic density, lower sigma b, MOE, sigma a and E, was more vulnerable to cavitation, but had higher ks100. Basic density was negatively correlated to Psi50 and ks100. We therefore found a tradeoff between Psi50 and ks100. Clones with high basic density had significantly lower hydraulic vulnerability, but also lower hydraulic conductivity at full saturation and thus less rapid growth than clones with low basic density. This tradeoff involved a negative relationship between Psi50 and sigma b as well as MOE, and between ks100 and sigma b, MOE and sigma a. Basic density and Psi50 showed no site-specific differences, but tree height, diameter at breast height, ks100 and mechanical strength and stiffness were significantly lower at the drier site. Basic density had no influence on the site-dependent differences in hydraulic and mechanical properties, but was strongly negatively related to diameter at breast height. Selecting for growth may thus lead not only to a reduction in mechanical strength and stiffness but also to a reduction in

  9. Microbial Activity in Forest Soil Under Beech, Spruce, Douglas Fir and Fir

    Directory of Open Access Journals (Sweden)

    Hajnal-Jafari Timea

    2016-08-01

    Full Text Available The aim of this research was to investigate the microbial activity in forest soil from different sites under deciduous and coniferous trees in Serbia. One site on Stara planina was under beech trees (Fagus sp. while another under mixture of spruce (Picea sp. and Douglas fir (Pseudotsuga sp.. The site on Kopaonik was under mixture of beech (Fagus sp. and spruce (Picea sp. trees. The site on Tara was dominantly under fir (Abies sp., beech (Fagus sp. and spruce (Picea sp.. The total number of bacteria, the number of actinobacteria, fungi and microorganisms involved in N and C cycles were determined using standard method of agar plates. The activities of dehydrogenase and ß-glucosidase enzymes were measured by spectrophotometric methods. The microbial activity was affected by tree species and sampling time. The highest dehydrogenase activity, total number of bacteria, number of actinobacteria, aminoheterotrophs, amylolytic and cellulolytic microorganisms were determined in soil under beech trees. The highest total number of fungi and number of pectinolytic microorganisms were determined in soil under spruce and Douglas fir trees. The correlation analyses proved the existence of statistically significant interdependency among investigated parameters.

  10. The wind and fire disturbance in Central European mountain spruce forests: the regeneration after four years

    Directory of Open Access Journals (Sweden)

    Monika Budzáková

    2013-03-01

    Full Text Available A strong windstorm in November 2004 resulted in a huge blown-down spruce forest area in the southern part of the Tatra National Park in the Western Carpathians in Slovakia, Central Europe. The aim of this work is to study the vegetation composition of spruce forest at differently managed sites four years after this disturbance. Four study areas were selected for this purpose: (i an area where the fallen trees were extracted and new seedlings were planted; (ii an area, which was hit by a forest fire after the extraction; (iii an area where no active management was applied; (iv a reference forest unaffected by such disturbance. A total of 100 plots were selected, 25 of each area type. The result of DCA and CCA analyses consistently indicated that after this short period the non-extracted and extracted areas are currently most similar to the reference forest area, while the fire affected area differed. A one-way ANOVA comparing species cover for the different plot sizes indicated some significant differences between the extracted and non-extracted plots. The abundance of certain species commonly occurring in spruce forests, such as Dyopteris carthusiana agg., Vaccinium myrtillus and Avenella flexuosa, correlated weli with the non-extracted plots, compared to the extracted plots. Coverage of these species was lowest on burned plots. The lowest Shannon-Wiener’s diversity values were recorded in burned plots. This was most likely a consequence of mono-dominant competitive species spread, (mainly Chamerion angustifolium which profited from the altered ecological conditions following the fire. Although some differences were also registered in the Shannon-Wiener diversity index between the remaining research plots, however these were not statistically significant. The most important results of our investigations include the extensive influence of fire disturbance on vegetation. Study revealed that the wind-disturbed area is able to regenerate

  11. TALL HERB SPRUCE FORESTS AS CLIMAX COMMUNITIES ON LOWLAND SWAMPS OF BRYANSK POLESIE

    Directory of Open Access Journals (Sweden)

    O. I. Evstigneev

    2017-09-01

    Full Text Available Nettle grey alder forests are a dominant forest type on lowland swamps in the Bryansk Polesie. They are formed as a result of repeated cuttings in the place of tall herb spruce forests. Tall herb spruce forests are very rare communities in the vegetation cover in this area due to clear cutting, melioration and peat extraction. An assessment of the succession status of tall herb spruce forests and nettle grey alder forests was carried out in this paper. The criteria of climax state and succession state of communities, developed for Eastern European forests, were used. These criteria are based on the degree of intensity of the following signs in the community: 1 the completeness of species composition of tree synusia; 2 the ontogenetic structure of tree species cenopopulation; 3 the gap-mosaic stand structure; 4 the diversity of microsites in soil cover; 5 the completeness of species composition and ecological-coenotic diversity of vascular species. We showed that tall herb spruce forest, as opposed to black alder forest, is close to communities of the climax type. This is evidenced by the following features of cenosis: firstly, all tree species in the area that covers the Bryansk Polesie and that are able to grow on lowland swamps are represented in the spruce forest (Alnus glutinosa, Betula pubescens, Fraxinus excelsior, Padus avium, Picea abies, Salix pentandra, Sorbus aucuparia, Ulmus glabra. Secondly, a steady turnover of generations is carried out in the cenopopulations of main edificators (Picea abies and Alnus glutinosa. This is evidenced by the complete and left-sided structure of their ontogenetic spectrum. Thirdly, a system of asynchronously developing gaps (parcels, which are formed on the site of old tree falls, is formed in the community. This ensures the continuous renewal of spruce and alder populations and creates conditions for the regeneration of other tree species. Fourthly, the structure of biogenic microsites has been formed

  12. A 4-year record of sitka spruce and western hemlock seed fall on the Cascade Head Experimental Forest.

    Science.gov (United States)

    Robert H. Ruth; Carl M. Berntsen

    1955-01-01

    Four years' measurement of seed fall in the spruce-hemlock type on the Cascade Head Experimental Forest indicates that an ample supply of seed is distributed over clear-cut areas under staggered-setting cutting. The largest tract sampled was 81 acres; in spite of a seed crop failure in 1950, it received an average of 243,000 viable spruce and hemlock seeds per...

  13. Forest floor carbon exchange of a boreal black spruce forest in eastern North America

    Science.gov (United States)

    Bergeron, O.; Margolis, H. A.; Coursolle, C.

    2009-09-01

    This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow (5 cm) soil temperature explained 67-86% of the variation in Rs-auto for all ground cover types, while deeper (50 and 100 cm) soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pff-max) saturated at low irradiance levels (~200 μmol m-2 s-1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pff-max was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5-8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied from 13 to 24% over the snow-free period and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17

  14. Forest Floor Carbon Exchange of a Boreal Black Spruce Forest in Eastern Canada

    Science.gov (United States)

    Bergeron, O.; Margolis, H. A.; Coursolle, C.

    2009-06-01

    This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow soil temperature explained 67-86% of the variation in Rs-auto for all ground cover types, while deeper soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pffmax) saturated at low irradiance levels (~200 μmol m-2 s-1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pffmax was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5-8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied seasonally from 13 to 24% and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17-18% of Peco depending on the year and the

  15. Biochemical indicators for novel forest decline in spruce

    International Nuclear Information System (INIS)

    Baur, M.; Lauchert, U.; Wild, A.

    1998-01-01

    The impact of air pollution on 24 stands of spruce trees in several regions in Germany was investigated. We looked for evidence of biochemical and physiological change at the level of the photosynthetic thylakoid membranes as well as for changes in the antioxidative system in two year old needles. We observed that, as the chlorophyll content decreases in the needles, the among of D1 protein declines far more rapidly in relation to the redox components P700 and cytochrome f. Consequently, the PSII/PSI stoichiometry keeps dropping to progressively lower, meaning unfavorable, values at the chlorophyll content diminishes. This is particularly the case in the higher elevation characteristically increases while the D1 protein content falls. The higher α-tocopherol values, however, are obviously neither able to protect the D1 protein from degradation nor to compensate for the higher oxidative stress. Apart from that the ascorbate/tocopherol ratios remained in the majority of cases in the unfavorable range of far below 10, where an effective protection of the membranes from free radicals is not guaranteed. This then is mirrored in the increased degradation of D1 and the lower PSII/PSI ratio

  16. Effects of bark beetle attack on canopy fuel flammability and crown fire potential in lodgepole pine and Engelmann spruce forests

    Science.gov (United States)

    Wesley G. Page; Martin E. Alexander; Michael J. Jenkins

    2015-01-01

    Large wildland fires in conifer forests typically involve some degree of crowning, with their initiation and propagation dependent upon several characteristics of the canopy fuels. Recent outbreaks of mountain pine beetle (Dendroctonus ponderosae Hopkins) in lodgepole pine (Pinus contorta Dougl. var. latifolia E ngelm.) forests and spruce beetle (Dendroctonus...

  17. Ecophysiology of seedling establishment in contrasting spruce-fir forests of southern Appalachian and Rocky Mountain ecotones, USA

    Science.gov (United States)

    William K. Smith; Keith N.C. Reinhardt; Daniel M. Johnson

    2010-01-01

    Fraser fir (Abies fraseri [Pursh] Poiret) and red spruce (Picea rubens Sarg.) occur as codominant trees in six relic, mountain-top populations that make up the high-elevation forests of the Southern Appalachian Mountains (SA). These two relic species of the former boreal forest have experienced a significant decline over the past...

  18. Susceptibility of burned black spruce (Picea mariana) forests to non-native plant invasions in interior Alaska

    Science.gov (United States)

    Katie V. Spellman; Christa P.H. Mulder; Teresa N. Hollingsworth

    2014-01-01

    As climate rapidly warms at high-latitudes, the boreal forest faces the simultaneous threats of increasing invasive plant abundances and increasing area burned by wildfire. Highly flammable and widespread black spruce (Picea mariana) forest represents a boreal habitat that may be increasingly susceptible to non-native plant invasion. This study assess the role of burn...

  19. Central-European mountain spruce (Picea abies (L.) Karst.) forests: regeneration of tree species after a bark beetle outbreak

    Czech Academy of Sciences Publication Activity Database

    Jonášová, Magda; Prach, Karel

    2004-01-01

    Roč. 23, č. 1 (2004), s. 15-27 ISSN 0925-8574 Institutional research plan: CEZ:AV0Z6087904 Keywords : forest management * mountain spruce forest * natural regeneration Subject RIV: GK - Forestry Impact factor: 0.890, year: 2004 http://www.sciencedirect.com

  20. Ecological Factors Influencing Norway Spruce Regeneration on Nurse Logs in a Subalpine Virgin Forest

    Directory of Open Access Journals (Sweden)

    Sophie Stroheker

    2018-03-01

    Full Text Available Regeneration of Picea abies in high-elevation mountain forests often depends on the presence of coarse woody debris (CWD, as logs provide sites with more favorable conditions for spruce regeneration compared to the forest floor. However, there is little quantitative knowledge on the factors that are conducive to or hindering spruce establishment on CWD. We examined spruce regeneration on CWD by sampling 303 plots (50 cm × 50 cm each on 56 downed logs in a virgin forest in the Swiss Alps. Variables describing microsite conditions were measured, and fungi were isolated from wood samples. To investigate the relationship between the ecological factors and establishment success, two models were fitted with seedling and sapling density as response variables, respectively. Besides log diameter, the models identified different ecological factors as significant for seedling and sapling establishment, i.e., regeneration depends on different factors in different development stages. Seedling density depended on the type of rot, log inclination, and decay stage. Sapling density depended mainly on light availability, cover by bark and moss, the time of tree fall, and the distance between the log surface and the forest floor. A total of 22 polypore fungi were isolated from the wood samples, four of them being threatened species. White- and brown-rot fungi were found in all decay stages. The visual assessment of the type of rot in the field corresponded in only 15% of cases to the type of rot caused by the isolated fungi; hence caution is needed when making field assessments of rot types.

  1. Stable carbon isotope analysis reveals widespread drought stress in boreal black spruce forests.

    Science.gov (United States)

    Walker, Xanthe J; Mack, Michelle C; Johnstone, Jill F

    2015-08-01

    Unprecedented rates of climate warming over the past century have resulted in increased forest stress and mortality worldwide. Decreased tree growth in association with increasing temperatures is generally accepted as a signal of temperature-induced drought stress. However, variations in tree growth alone do not reveal the physiological mechanisms behind recent changes in tree growth. Examining stable carbon isotope composition of tree rings in addition to tree growth can provide a secondary line of evidence for physiological drought stress. In this study, we examined patterns of black spruce growth and carbon isotopic composition in tree rings in response to climate warming and drying in the boreal forest of interior Alaska. We examined trees at three nested scales: landscape, toposequence, and a subsample of trees within the toposequence. At each scale, we studied the potential effects of differences in microclimate and moisture availability by sampling on northern and southern aspects. We found that black spruce radial growth responded negatively to monthly metrics of temperature at all examined scales, and we examined ∆(13)C responses on a subsample of trees as representative of the wider region. The negative ∆(13)C responses to temperature reveal that black spruce trees are experiencing moisture stress on both northern and southern aspects. Contrary to our expectations, ∆(13)C from trees on the northern aspect exhibited the strongest drought signal. Our results highlight the prominence of drought stress in the boreal forest of interior Alaska. We conclude that if temperatures continue to warm, we can expect drought-induced productivity declines across large regions of the boreal forest, even for trees located in cool and moist landscape positions. © 2015 John Wiley & Sons Ltd.

  2. The complete nitrogen cycle of an N-saturated spruce forest ecosystem.

    Science.gov (United States)

    Kreutzer, K; Butterbach-Bahl, K; Rennenberg, H; Papen, H

    2009-09-01

    Long-term nitrogen deposition into forest ecosystems has turned many forests in Central Europe and North America from N-limited to N-saturated systems, with consequences for climate as well as air and groundwater quality. However, complete quantification of processes that convert the N deposited and contributed to ecosystem N cycling is scarce. In this study, we provide the first complete quantification of external and internal N fluxes in an old-growth spruce forest, the Höglwald, Bavaria, Germany, exposed to high chronic N deposition. In this forest, N cycling is dominated by high rates of mineralisation of soil organic matter, nitrification and immobilisation of ammonium and nitrate into microbial biomass. The amount of ammonium available is sufficient to cover the entire N demand of the spruce trees. The data demonstrate the existence of a highly dynamic internal N cycle within the soil, driven by growth and death of the microbial biomass, which turns over approximately seven times each year. Although input and output fluxes are of high environmental significance, they are low compared to the internal fluxes mediated by microbial activity.

  3. Development of Somatic Embryo Maturation and Growing Techniques of Norway Spruce Emblings towards Large-Scale Field Testing

    Directory of Open Access Journals (Sweden)

    Mikko Tikkinen

    2018-06-01

    Full Text Available The possibility to utilize non-additive genetic gain in planting stock has increased the interest towards vegetative propagation. In Finland, the increased planting of Norway spruce combined with fluctuant seed yields has resulted in shortages of improved regeneration material. Somatic embryogenesis is an attractive method to rapidly facilitate breeding results, not in the least, because juvenile propagation material can be cryostored for decades. Further development of technology for the somatic embryogenesis of Norway spruce is essential, as the high cost of somatic embryo plants (emblings limits deployment. We examined the effects of maturation media varying in abscisic acid (20, 30 or 60 µM and polyethylene glycol 4000 (PEG concentrations, as well as the effect of cryopreservation cycles on embryo production, and the effects of two growing techniques on embling survival and growth. Embryo production and nursery performance of 712 genotypes from 12 full-sib families were evaluated. Most embryos per gram of fresh embryogenic mass (296 ± 31 were obtained by using 30 µM abscisic acid without PEG in the maturation media. Transplanting the emblings into nursery after one-week in vitro germination resulted in 77% survival and the tallest emblings after the first growing season. Genotypes with good production properties were found in all families.

  4. Historical and projected carbon balance of mature black spruce ecosystems across north america: The role of carbon-nitrogen interactions

    Science.gov (United States)

    Clein, Joy S.; McGuire, A.D.; Zhang, X.; Kicklighter, D.W.; Melillo, J.M.; Wofsy, S.C.; Jarvis, P.G.; Massheder, J.M.

    2002-01-01

    simulated NEP (R2 = 0.36, 0.20 for coupled and uncoupled simulations, respectively) was similar to the correlations at the northern site. To evaluate the role of N dynamics in C balance of black spruce ecosystems across North America, we simulated historical and projected C dynamics from 1900 to 2100 with a global-based climatology at 0.5?? resolution (latitude ?? longitude) with both the coupled and uncoupled parameterizations of TEM. From analyses at the northern site, several consistent patterns emerge. There was greater inter-annual variability in net primary production (NPP) simulated by the uncoupled parameterization as compared to the coupled parameterization, which led to substantial differences in inter-annual variability in NEP between the parameterizations. The divergence between NPP and heterotrophic respiration was greater in the uncoupled simulation, resulting in more C sequestration during the projected period. These responses were the result of fundamentally different responses of the coupled and uncoupled parameterizations to changes in CO2 and climate. Across North American black spruce ecosystems, the range of simulated decadal changes in C storage was substantially greater for the uncoupled parameterization than for the coupled parameterization. Analysis of the spatial variability in decadal responses of C dynamics revealed that C fluxes simulated by the coupled and uncoupled parameterizations have different sensitivities to climate and that the climate sensitivities of the fluxes change over the temporal scope of the simulations. The results of this study suggest that uncertainties can be reduced through (1) factorial studies focused on elucidating the role of C and N interactions in the response of mature black spruce ecosystems to manipulations of atmospheric CO2 and climate, (2) establishment of a network of continuous, long-term measurements of C dynamics across the range of mature black spruce ecosystems in North America, and (3) ancillary

  5. Growth of mature boreal Norway spruce was not affected by elevated [CO(2)] and/or air temperature unless nutrient availability was improved.

    Science.gov (United States)

    Sigurdsson, Bjarni D; Medhurst, Jane L; Wallin, Göran; Eggertsson, Olafur; Linder, Sune

    2013-11-01

    The growth responses of mature Norway spruce (Picea abies (L.) Karst.) trees exposed to elevated [CO(2)] (CE; 670-700 ppm) and long-term optimized nutrient availability or elevated air temperature (TE; ±3.9 °C) were studied in situ in northern Sweden in two 3 year field experiments using 12 whole-tree chambers in ca. 40-year-old forest. The first experiment (Exp. I) studied the interactions between CE and nutrient availability and the second (Exp. II) between CE and TE. It should be noted that only air temperature was elevated in Exp. II, while soil temperature was maintained close to ambient. In Exp. I, CE significantly increased the mean annual height increment, stem volume and biomass increment during the treatment period (25, 28, and 22%, respectively) when nutrients were supplied. There was, however, no significant positive CE effect found at the low natural nutrient availability. In Exp. II, which was conducted at the natural site fertility, neither CE nor TE significantly affected height or stem increment. It is concluded that the low nutrient availability (mainly nitrogen) in the boreal forests is likely to restrict their response to the continuous rise in [CO(2)] and/or TE.

  6. Measurements of ammonia concentrations, fluxes and dry deposition velocities to a spruce forest 1991-1995

    DEFF Research Database (Denmark)

    Andersen, H.V.; Hovmand, M.F.; Hummelshøj, P.

    1999-01-01

    The dry deposition velocities and fluxes of ammonia have been estimated from measurements of the vertical gradient of ammonia and micrometeorology above a spruce forest in western Jutland, Denmark. Measurements have been made in seven periods, each lasting about one week and covering all seasons...... measuring period characterized by easterly winds with dry conditions and high ammonia concentrations, and the emissions might relate to evaporation from ammonia saturated surfaces or emission from mineralization in the forest soil. In general, relatively high net deposition velocities were observed during...... at conditions with easterly winds, the air have passed central Jutland with large emission areas. Some of the relatively low deposition velocities or emissions were observed during conditions with low ammonia concentration and westerly winds. These observations might relate to a compensation point of the forest...

  7. Natural regeneration ecology of a secondary altimontane spruce forests at Jelendol

    OpenAIRE

    Rozman, Elizabeta; Diaci, Jurij

    2008-01-01

    Natural regeneration of altimontane spruce forests at Jelendol is retarded dueto many factors. In autumn 2003, gaps of different size and parts of the surrounding stand were covered with a 5 x 5 grid m to define sampling plots. Atotal of 227 plots with 1,5 x 1,5 m in size were installed to analyse generalregeneration conditions and inhibitors. The following ecological parameters were estimated on each plot: micro relief, inclination, soil depth,ground cover, direct and diffuse solar radiation...

  8. Genetic variability and health of Norway spruce stands in the Regional Directorate of the State Forests in Krosno

    Directory of Open Access Journals (Sweden)

    Gutkowska Justyna

    2017-03-01

    Full Text Available The study was conducted in 2015 in six spruce stands situated in different forest districts administratively belonging to the Regional Directorate of State Forests in Krosno. Each spruce population was represented by 30 trees and assessed in terms of their current health status. Genetic analyses were performed on shoot samples from each tree using nine nuclear DNA markers and one mitochondrial DNA marker (nad1. The health status of the trees was described according to the classification developed by Szczepkowski and Tarasiuk (2005 and the correlation between health classes and the level of genetic variability was computed with STATISTICA (α = 0.05.

  9. Forest floor carbon exchange of a boreal black spruce forest in eastern North America

    Directory of Open Access Journals (Sweden)

    O. Bergeron

    2009-09-01

    Full Text Available This study reports continuous automated measurements of forest floor carbon (C exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto and forest floor photosynthesis (Pff to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj and Pff (Pff-eco relative to that of total ecosystem respiration (Re and photosynthesis (Peco, respectively, were also quantified.

    Shallow (5 cm soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper (50 and 100 cm soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring.

    Maximum photosynthetic capacity of the forest floor (Pff-max saturated at low irradiance levels (~200 μmol m−2 s−1 and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pff-max was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two

  10. Vertical divergence of fogwater fluxes above a spruce forest

    Science.gov (United States)

    Burkard, R.; Eugster, W.; Wrzesinsky, T.; Klemm, O.

    Two almost identical eddy covariance measurement setups were used to measure the fogwater fluxes to a forest ecosystem in the "Fichtelgebirge" mountains (Waldstein research site, 786 m a.s.l.) in Germany. During the first experiment, an intercomparison was carried out with both setups running simultaneously at the same measuring height on a meteorological tower, 12.5 m above the forest canopy. The results confirmed a close agreement of the turbulent fluxes between the two setups, and allowed to intercalibrate liquid water content (LWC) and gravitational fluxes. During the second experiment, the setups were mounted at a height of 12.5 and 3 m above the canopy, respectively. For the 22 fog events, a persistent negative flux divergence was observed with a greater downward flux at the upper level. To extrapolate the turbulent liquid water fluxes measured at height z to the canopy of height hc, a conversion factor 1/[1+0.116( z- hc)] was determined. For the fluxes of nonvolatile ions, no such correction is necessary since the net evaporation of the fog droplets appears to be the primary cause of the vertical flux divergence. Although the net evaporation reduces the liquid water flux reaching the canopy, it is not expected to change the absolute amount of ions dissolved in fogwater.

  11. Decomposition of soil organic matter from boreal black spruce forest: Environmental and chemical controls

    Science.gov (United States)

    Wickland, K.P.; Neff, J.C.

    2008-01-01

    Black spruce forests are a dominant covertype in the boreal forest region, and they inhabit landscapes that span a wide range of hydrologic and thermal conditions. These forests often have large stores of soil organic carbon. Recent increases in temperature at northern latitudes may be stimulating decomposition rates of this soil carbon. It is unclear, however, how changes in environmental conditions influence decomposition in these systems, and if substrate controls of decomposition vary with hydrologic and thermal regime. We addressed these issues by investigating the effects of temperature, moisture, and organic matter chemical characteristics on decomposition of fibric soil horizons from three black spruce forest sites. The sites varied in drainage and permafrost, and included a "Well Drained" site where permafrost was absent, and "Moderately well Drained" and "Poorly Drained" sites where permafrost was present at about 0.5 m depth. Samples collected from each site were incubated at five different moisture contents (2, 25, 50, 75, and 100% saturation) and two different temperatures (10??C and 20??C) in a full factorial design for two months. Organic matter chemistry was analyzed using pyrolysis gas chromatography-mass spectrometry prior to incubation, and after incubation on soils held at 20??C, 50% saturation. Mean cumulative mineralization, normalized to initial carbon content, ranged from 0.2% to 4.7%, and was dependent on temperature, moisture, and site. The effect of temperature on mineralization was significantly influenced by moisture content, as mineralization was greatest at 20??C and 50-75% saturation. While the relative effects of temperature and moisture were similar for all soils, mineralization rates were significantly greater for samples from the "Well Drained" site compared to the other sites. Variations in the relative abundances of polysaccharide-derivatives and compounds of undetermined source (such as toluene, phenol, 4-methyl phenol, and

  12. Allocation pattern and accumulation potential of carbon stock in natural spruce forests in northwest China

    Directory of Open Access Journals (Sweden)

    Jun-Wei Yue

    2018-05-01

    Full Text Available Background The spruce forests are dominant communities in northwest China, and play a key role in national carbon budgets. However, the patterns of carbon stock distribution and accumulation potential across stand ages are poorly documented. Methods We investigated the carbon stocks in biomass and soil in the natural spruce forests in the region by surveys on 39 plots. Biomass of tree components were estimated using allometric equations previously established based on tree height and diameter at breast height, while biomass in understory (shrub and herb and forest floor were determined by total harvesting method. Fine root biomass was estimated by soil coring technique. Carbon stocks in various biomass components and soil (0–100 cm were estimated by analyzing the carbon content of each component. Results The results showed that carbon stock in these forest ecosystems can be as high as 510.1 t ha−1, with an average of 449.4 t ha−1. Carbon stock ranged from 28.1 to 93.9 t ha−1 and from 0.6 to 8.7 t ha−1 with stand ages in trees and deadwoods, respectively. The proportion of shrubs, herbs, fine roots, litter and deadwoods ranged from 0.1% to 1% of the total ecosystem carbon, and was age-independent. Fine roots and deadwood which contribute to about 2% of the biomass carbon should be attached considerable weight in the investigation of natural forests. Soil carbon stock did not show a changing trend with stand age, ranging from 254.2 to 420.0 t ha−1 with an average of 358.7 t ha−1. The average value of carbon sequestration potential for these forests was estimated as 29.4 t ha−1, with the lower aged ones being the dominant contributor. The maximum carbon sequestration rate was 2.47 t ha−1 year−1 appearing in the growth stage of 37–56 years. Conclusion The carbon stock in biomass was the major contributor to the increment of carbon stock in ecosystems. Stand age is not a good predictor of soil carbon stocks and accurate

  13. Ground vegetation dynamics in mountain spruce (Picea abies (L.) Karsten) forests recovering after air pollution stress impact

    Czech Academy of Sciences Publication Activity Database

    Vávrová, Eva; Cudlín, O.; Vavříček, D.; Cudlín, Pavel

    2009-01-01

    Roč. 205, č. 2 (2009), s. 305-321 ISSN 1385-0237 R&D Projects: GA MŠk(CZ) OC 141 Institutional research plan: CEZ:AV0Z60870520 Keywords : forest decline * norway spruce * microsite conditions * recovery * understorey layer Subject RIV: GK - Forestry Impact factor: 1.567, year: 2009

  14. The historical role of Ips hauseri (Coleoptera: Curculionidae) in the spruce forest of Ile-Alatausky and Medeo National Parks

    Science.gov (United States)

    N. Mukhamadiev; A. Lynch; C. O' Connor; A. Sagitov; N. Ashikbaev; I. Panyushkina

    2014-01-01

    On 17 May and 27 June 2011 severe cyclonic storms damaged several hundred hectares of spruce forest (Picea schrenkiana) in the Tian Shan Mountains. Bark beetle populations increased rapidly in dead and damaged trees, particularly Ips hauseri, I. typographus, I. sexdentatus, and Piiyogenesperfossus (all Coleoptera: Curculionidae), and there is concern about the...

  15. Building Resilience into Sitka Spruce (Picea sitchensis (Bong. Carr. Forests in Scotland in Response to the Threat of Climate Change

    Directory of Open Access Journals (Sweden)

    Andrew D. Cameron

    2015-02-01

    Full Text Available It is expected that a warming climate will have an impact on the future productivity of European spruce forests. In Scotland, Sitka spruce (Picea sitchensis (Bong. Carr. dominates the commercial forestry sector and there is growing pressure to develop alternative management strategies to limit potential economic losses through climate change. This review considers management options to increase the resilience of Sitka spruce dominated forests in Scotland. Given the considerable uncertainty over the potential long-term impacts of climate change, it is recommended that Sitka spruce should continue to be planted where it already grows well. However, new planting and restocking should be established in mixtures where silviculturally practicable, even if no-thin regimes are adopted, to spread future risks of damage. Three potentially compatible species with Sitka spruce are western hemlock (Tsuga heterophylla (Raf. Sarg., grand fir (Abies grandis (Lamb. Lindl. and Douglas fir (Pseudotsuga menziesii (Mirb. Franco and all form natural mixtures in its native range in North America. The predicted windier climate will require a range of management inputs, such as early cutting of extraction racks and early selective thinning, to improve stability. The potential to improve resilience to particularly abiotic damage through transforming even-aged stands into irregular structures and limiting the overall size of the growing stock is discussed.

  16. Changes of Soil Enzyme Activities in Different Restoration Ages of Spruce Forests on the Eastern Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-mei; BAO Wei-kai; PANG Xue-yong; WU Ning; ZHOU Guo-yi

    2005-01-01

    Six soil enzymes (invertase, acid phosphatase, proteinase, catalase, peroxidase and polyphenoloxidase ) were chosen for investigation under different spruce forests with restoration ages of 4,10,16 years and an old-growth spruce forest over 400 years old in the eastern Qinghai-Tibet Plateau, China. Results showed that the activities of invertase, phosphatase, proteinase, catalase and peroxidase decreased in newly restored forests except for pholyphenoloxidase. With the development of forests after restoration, the activities of invertase, acid phosphadase, proteinase increased gradually. Our study also indicated that the soil enzyme activities were associated with surface soils and decreased with depths. This result suggested that in the earlier restoration stage the application of organic fertilizer may be more effective by surface addition to soils than deep addition.

  17. Climatic control of stand thinning in unmanaged spruce forests of the southern taiga in European Russia

    International Nuclear Information System (INIS)

    Vygodskaya, N.N.; Schulze, E.D.; Tchebakova, N.M.

    2002-01-01

    The demography of Picea abies trees was studied over a period of about 30 yr on permanent plots in six forest types of an unmanaged forest located in a forest reserve of the Southern Taiga, NW of Moscow. This study encompassed a broad range of conditions that are typical for old growth spruce forests in the boreal region, including sites with a high water table and well drained sites, podzolic soils, acidic soils and organic soils. At all sites stand density, tree height, breast height diameter and age has been periodically recorded since 1968. Tree density ranged between 178 and 1035 trees/ha for spruce and between 232 and 1168 trees/ha for the whole stand, including mainly Betula and Populus. Biomass ranged between 5.4 and 170 tdw/ha for spruce and between 33 to 198 tdw/ha for the whole stand. Averaged over a long period of time, biomass did not change with stand density according to the self-thinning rule. In fact, on most sites biomass remained almost constant in the long term, while stand density decreased. The study demonstrates that the loss of living trees was not regulated by competitive interactions between trees, but by disturbances caused by climatic events. Dry years caused losses of minor and younger trees without affecting biomass. In contrast, periodic storms resulted in a loss of biomass without affecting density, except for extreme events, where the whole stand may fall. Dry years followed by wet years enhance the effect on stand density. Since mainly younger trees were lost, the apparent average age of the stand increased more than real time (20% for Picea). Average mortality was 2.8 ± 0.5% yr 1 for spruce. Thus, the forest is turned over once every 160-180 yr by disturbances. The demography of dead trees shows that the rate of decay depends on the way the tree died. Storm causes uprooting and stem breakage, where living trees fall to the forest floor and decay with a mean residence time (t1/2) of about 16 yr (decomposition rate constant k d = 0

  18. Comparing modern and presettlement forest dynamics of a subboreal wilderness: Does spruce budworm enhance fire risk?

    Science.gov (United States)

    Sturtevant, Brian R.; Miranda, Brian R.; Shinneman, Douglas J.; Gustafson, Eric J.; Wolter, Peter T.

    2012-01-01

    Insect disturbance is often thought to increase fire risk through enhanced fuel loadings, particularly in coniferous forest ecosystems. Yet insect disturbances also affect successional pathways and landscape structure that interact with fire disturbances (and vice-versa) over longer time scales. We applied a landscape succession and disturbance model (LANDIS-II) to evaluate the relative strength of interactions between spruce budworm (Choristoneura fumiferana) outbreaks and fire disturbances in the Boundary Waters Canoe Area (BWCA) in northern Minnesota (USA). Disturbance interactions were evaluated for two different scenarios: presettlement forests and fire regimes vs. contemporary forests and fire regimes. Forest composition under the contemporary scenario trended toward mixtures of deciduous species (primarily Betula papyrifera and Populus spp.) and shade-tolerant conifers (Picea mariana, Abies balsamea, Thuja occidentalis), with disturbances dominated by a combination of budworm defoliation and high-severity fires. The presettlement scenario retained comparatively more “big pines” (i.e., Pinus strobus, P. resinosa) and tamarack (L. laricina), and experienced less budworm disturbance and a comparatively less-severe fire regime. Spruce budworm disturbance decreased area burned and fire severity under both scenarios when averaged across the entire 300-year simulations. Contrary to past research, area burned and fire severity during outbreak decades were each similar to that observed in non-outbreak decades. Our analyses suggest budworm disturbances within forests of the BWCA have a comparatively weak effect on long-term forest composition due to a combination of characteristics. These include strict host specificity, fine-scaled patchiness created by defoliation damage, and advance regeneration of its primary host, balsam fir (A. balsamea) that allows its host to persist despite repeated disturbances. Understanding the nature of the three-way interaction

  19. Effect of Organic Layer Thickness on Black Spruce Aging Mistakes in Canadian Boreal Forests

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    Ahmed Laamrani

    2016-03-01

    Full Text Available Boreal black spruce (Picea mariana forests are prone to developing thick organic layers (paludification. Black spruce is adapted to this environment by the continuous development of adventitious roots, masking the root collar and making it difficult to age trees. Ring counts above the root collar underestimate age of trees, but the magnitude of age underestimation of trees in relation to organic layer thickness (OLT is unknown. This age underestimation is required to produce appropriate age-correction tools to be used in land resource management. The goal of this study was to assess aging errors that are done with standard ring counts of trees growing in sites with different degrees of paludification (OLT; 0–25 cm, 26–65 cm, >65 cm. Age of 81 trees sampled at three geographical locations was determined by ring counts at ground level and at 1 m height, and real age of trees was determined by cross-dating growth rings down to the root collar (root/shoot interface. Ring counts at 1 m height underestimated age of trees by a mean of 22 years (range 13–49 and 52 years (range 14–112 in null to low vs. moderately to highly paludified stands, respectively. The percentage of aging-error explained by our linear model was relatively high (R2adj = 0.71 and showed that OLT class and age at 0-m could be used to predict total aging-error while neither DBH nor geographic location could. The resulting model has important implications for forest management to accurately estimate productivity of these forests.

  20. Yield Responses of Black Spruce to Forest Vegetation Management Treatments: Initial Responses and Rotational Projections

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    Peter F. Newton

    2012-01-01

    Full Text Available The objectives of this study were to (1 quantitatively summarize the early yield responses of black spruce (Picea mariana (Mill. B.S.P. to forest vegetation management (FVM treatments through a meta-analytical review of the scientific literature, and (2 given (1, estimate the rotational consequences of these responses through model simulation. Based on a fixed-effects meta-analytic approach using 44 treated-control yield pairs derived from 12 experiments situated throughout the Great Lakes—St. Lawrence and Canadian Boreal Forest Regions, the resultant mean effect size (response ratio and associated 95% confidence interval for basal diameter, total height, stem volume, and survival responses, were respectively: 54.7% (95% confidence limits (lower/upper: 34.8/77.6, 27.3% (15.7/40.0, 198.7% (70.3/423.5, and 2.9% (−5.5/11.8. The results also indicated that early and repeated treatments will yield the largest gains in terms of mean tree size and survival. Rotational simulations indicated that FVM treatments resulted in gains in stand-level operability (e.g., reductions of 9 and 5 yr for plantations established on poor-medium and good-excellent site qualities, resp.. The challenge of maintaining coniferous forest cover on recently disturbed sites, attaining statutory-defined free-to-grow status, and ensuring long-term productivity, suggest that FVM will continue to be an essential silvicultural treatment option when managing black spruce plantations.

  1. Is it possible and necessary to control European spruce bark beetle Ips typographus (L. outbreak in the Białowieża Forest?

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    Hilszczański Jacek

    2017-03-01

    Full Text Available In response to the information published in ‘Forest Research Papers’ (vol. 77(4, 2016, regarding the problem of the European spruce bark beetle Ips typographus (L. in the Białowieża Forest, we present our viewpoint on this issue. The role of the European spruce bark beetle in the Białowieża Forest is discussed based on the experience gained in Europe’s forests. We present the effects of I. typographus outbreaks on forest biodiversity as well as outbreak mitigation in the context of the processes taking place in semi-natural forests.

  2. Natural regeneration ecology of a secondary altimontane spruce forests at Jelendol

    International Nuclear Information System (INIS)

    Rozman, E.; Diaci, J.

    2008-01-01

    Natural regeneration of altimontane spruce forests at Jelendol is retarded due to many factors. In autumn 2003, gaps of different size and parts of the surrounding stand were covered with a 5 x 5 grid m to define sampling plots. A total of 227 plots with 1,5 x 1,5 m in size were installed to analyse general regeneration conditions and inhibitors. The following ecological parameters were estimated on each plot: micro relief, inclination, soil depth,ground cover, direct and diffuse solar radiation. Woody regeneration (density, height, height increment) and ground vegetation were recorded at each plot. Considering that N-S and E-W radiation asymmetry was explicit, the distribution of direct and diffuse radiation was divided into four groups among the plots. Spruce regeneration (28.,605 per ha) was mainly found at the edge of the large gap, though total regeneration density and radiation were not correlated. However, in both the stand and the small gaps, the lack of radiation hindered further development. This study showed that light conditions were not the only factors affecting the regeneration success at an altitude of 1,500 m. The presence of woody debris was important, while the influence of the herb layer (predominant species were Festuca altissima All. and Calamagrostis arundinacea (L.) Roth.) and soil depth proved to be negative. The impact of browsing, however, remained the main problem. (author)

  3. Negative impacts of high temperatures on growth of black spruce forests intensify with the anticipated climate warming.

    Science.gov (United States)

    Girardin, Martin P; Hogg, Edward H; Bernier, Pierre Y; Kurz, Werner A; Guo, Xiao Jing; Cyr, Guillaume

    2016-02-01

    An increasing number of studies conclude that water limitations and heat stress may hinder the capacity of black spruce (Picea mariana (Mill.) B.S.P.) trees, a dominant species of Canada's boreal forests, to grow and assimilate atmospheric carbon. However, there is currently no scientific consensus on the future of these forests over the next century in the context of widespread climate warming. The large spatial extent of black spruce forests across the Canadian boreal forest and associated variability in climate, demography, and site conditions pose challenges for projecting future climate change responses. Here we provide an evaluation of the impacts of climate warming and drying, as well as increasing [CO2 ], on the aboveground productivity of black spruce forests across Canada south of 60°N for the period 1971 to 2100. We use a new extensive network of tree-ring data obtained from Canada's National Forest Inventory, spatially explicit simulations of net primary productivity (NPP) and its drivers, and multivariate statistical modeling. We found that soil water availability is a significant driver of black spruce interannual variability in productivity across broad areas of the western to eastern Canadian boreal forest. Interannual variability in productivity was also found to be driven by autotrophic respiration in the warmest regions. In most regions, the impacts of soil water availability and respiration on interannual variability in productivity occurred during the phase of carbohydrate accumulation the year preceding tree-ring formation. Results from projections suggest an increase in the importance of soil water availability and respiration as limiting factors on NPP over the next century due to warming, but this response may vary to the extent that other factors such as carbon dioxide fertilization, and respiration acclimation to high temperature, contribute to dampening these limitations. © 2015 Her Majesty the Queen in Right of Canada. Reproduced with

  4. Physiological acclimation dampens initial effects of elevated temperature and atmospheric CO2 concentration in mature boreal Norway spruce.

    Science.gov (United States)

    Lamba, Shubhangi; Hall, Marianne; Räntfors, Mats; Chaudhary, Nitin; Linder, Sune; Way, Danielle; Uddling, Johan; Wallin, Göran

    2018-02-01

    Physiological processes of terrestrial plants regulate the land-atmosphere exchange of carbon, water, and energy, yet few studies have explored the acclimation responses of mature boreal conifer trees to climate change. Here we explored the acclimation responses of photosynthesis, respiration, and stomatal conductance to elevated temperature and/or CO 2 concentration ([CO 2 ]) in a 3-year field experiment with mature boreal Norway spruce. We found that elevated [CO 2 ] decreased photosynthetic carboxylation capacity (-23% at 25 °C) and increased shoot respiration (+64% at 15 °C), while warming had no significant effects. Shoot respiration, but not photosynthetic capacity, exhibited seasonal acclimation. Stomatal conductance at light saturation and a vapour pressure deficit of 1 kPa was unaffected by elevated [CO 2 ] but significantly decreased (-27%) by warming, and the ratio of intercellular to ambient [CO 2 ] was enhanced (+17%) by elevated [CO 2 ] and decreased (-12%) by warming. Many of these responses differ from those typically observed in temperate tree species. Our results show that long-term physiological acclimation dampens the initial stimulation of plant net carbon assimilation to elevated [CO 2 ], and of plant water use to warming. Models that do not account for these responses may thus overestimate the impacts of climate change on future boreal vegetation-atmosphere interactions. © 2017 John Wiley & Sons Ltd.

  5. Climatic Sensitivity of a Mixed Forest Association of White Spruce and Trembling Aspen at Their Southern Range Limit

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    Sophan Chhin

    2016-10-01

    Full Text Available Climatic sensitivity of white spruce (Picea glauca (Moench Voss was examined growing in association with trembling aspen (Populus tremuloides Michx. at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.

  6. PCDD/F and PCB in spruce forests of the Alps

    Energy Technology Data Exchange (ETDEWEB)

    Offenthaler, I., E-mail: ivo.offenthaler@umweltbundesamt.a [Austrian Environment Agency, Spittelauer Laende 5, 1090 Vienna (Austria); Bassan, R. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Belis, C. [Regional Agency for Environmental Protection of Lombardia (Italy); Jakobi, G.; Kirchner, M. [Helmholtz Zentrum Muenchen (German Research Centre for Environmental Health) (Germany); Kraeuchi, N. [WSL-Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Moche, W. [Austrian Environment Agency, Spittelauer Laende 5, 1090 Vienna (Austria); Schramm, K.-W. [Helmholtz Zentrum Muenchen (German Research Centre for Environmental Health) (Germany); Sedivy, I. [WSL-Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Simoncic, P. [Slovenian Forestry Institute (Slovenia); Uhl, M.; Weiss, P. [Austrian Environment Agency, Spittelauer Laende 5, 1090 Vienna (Austria)

    2009-12-15

    PCDD/F and PCB concentrations in remote mountainous spruce stands of the Central European Alps show strong geographic variation. Independent of the matrix (0.5 year old needles, humus or mineral soil), the highest pollutant levels were always found at the lateral zones of the mountain range. High levels coincided with strong precipitation, particularly along the northern margin of the study region. The most volatile PCB congener propagated farther into the colder, drier central Alps than the heavier species. Matrices with different accumulation history (needles and humus) repeatedly reflected different spatial immission patterns. Consistent with its much longer exposure, pollutant levels in humus exceeded those of needles by up to two orders of magnitude. Needle contamination varied with altitude but the vertical trends were highly variable between transsects and changed between years, too. - Dioxin-like pollution of forests in the Alps shows strong geographic variation.

  7. Using Silviculture to Influence Carbon Sequestration in Southern Appalachian Spruce-Fir Forests

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    Patrick T. Moore

    2012-06-01

    Full Text Available Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C stored in standing forest stocks and the fate of forest products derived from harvesting. Over a 100-year simulation period the even-aged scenario (250 Mg C ha1 outperformed the no-action scenario (241 Mg C ha1 in total carbon (TC sequestered. The uneven-aged scenario approached 220 Mg C ha1, but did not outperform the no-action scenario within the simulation period. While the average annual change in C (AAC of the no-action scenario approached zero, or carbon neutral, during the simulation, both the even-aged and uneven-aged scenarios surpassed the no-action by year 30 and maintained positive AAC throughout the 100-year simulation. This study demonstrates that silvicultural treatment of forest stands can increase potential C storage, but that careful consideration of: (1 accounting method (i.e., TC versus AAC; (2 fate of harvested products and; (3 length of the planning horizon (e.g., 100 years will strongly influence the evaluation of C sequestration.

  8. Landscape heterogeneity, soil climate, and carbon exchange in a boreal black spruce forest.

    Science.gov (United States)

    Dunn, Allison L; Wofsy, Steven C; v H Bright, Alfram

    2009-03-01

    We measured soil climate and the turbulent fluxes of CO2, H2O, heat, and momentum on short towers (2 m) in a 160-yr-old boreal black spruce forest in Manitoba, Canada. Two distinct land cover types were studied: a Sphagnum-dominated wetland, and a feathermoss (Pleurozium and Hylocomium)-dominated upland, both lying within the footprint of a 30-m tower, which has measured whole-forest carbon exchange since 1994. Peak summertime uptake of CO2, was higher in the wetland than for the forest as a whole due to the influence of deciduous shrubs. Soil respiration rates in the wetland were approximately three times larger than in upland soils, and 30% greater than the mean of the whole forest, reflecting decomposition of soil organic matter. Soil respiration rates in the wetland were regulated by soil temperature, which was in turn influenced by water table depth through effects on soil heat capacity and conductivity. Warmer soil temperatures and deeper water tables favored increased heterotrophic respiration. Wetland drainage was limited by frost during the first half of the growing season, leading to high, perched water tables, cool soil temperatures, and much lower respiration rates than observed later in the growing season. Whole-forest evapotranspiration increased as water tables dropped, suggesting that photosynthesis in this forest was rarely subject to water stress. Our data indicate positive feedback between soil temperature, seasonal thawing, heterotrophic respiration, and evapotranspiration. As a result, climate warming could cause covariant changes in soil temperature and water table depths that may stimulate photosynthesis and strongly promote efflux of CO2 from peat soils in boreal wetlands.

  9. Height-Diameter Models for Mixed-Species Forests Consisting of Spruce, Fir, and Beech

    Directory of Open Access Journals (Sweden)

    Petráš Rudolf

    2014-06-01

    Full Text Available Height-diameter models define the general relationship between the tree height and diameter at each growth stage of the forest stand. This paper presents generalized height-diameter models for mixed-species forest stands consisting of Norway spruce (Picea abies Karst., Silver fir (Abies alba L., and European beech (Fagus sylvatica L. from Slovakia. The models were derived using two growth functions from the exponential family: the two-parameter Michailoff and three-parameter Korf functions. Generalized height-diameter functions must normally be constrained to pass through the mean stand diameter and height, and then the final growth model has only one or two parameters to be estimated. These “free” parameters are then expressed over the quadratic mean diameter, height and stand age and the final mathematical form of the model is obtained. The study material included 50 long-term experimental plots located in the Western Carpathians. The plots were established 40-50 years ago and have been repeatedly measured at 5 to 10-year intervals. The dataset includes 7,950 height measurements of spruce, 21,661 of fir and 5,794 of beech. As many as 9 regression models were derived for each species. Although the “goodness of fit” of all models showed that they were generally well suited for the data, the best results were obtained for silver fir. The coefficient of determination ranged from 0.946 to 0.948, RMSE (m was in the interval 1.94-1.97 and the bias (m was -0.031 to 0.063. Although slightly imprecise parameter estimation was established for spruce, the estimations of the regression parameters obtained for beech were quite less precise. The coefficient of determination for beech was 0.854-0.860, RMSE (m 2.67-2.72, and the bias (m ranged from -0.144 to -0.056. The majority of models using Korf’s formula produced slightly better estimations than Michailoff’s, and it proved immaterial which estimated parameter was fixed and which parameters

  10. Predicting adaptive phenotypes from multilocus genotypes in Sitka spruce (Picea sitchensis) using random forest.

    Science.gov (United States)

    Holliday, Jason A; Wang, Tongli; Aitken, Sally

    2012-09-01

    Climate is the primary driver of the distribution of tree species worldwide, and the potential for adaptive evolution will be an important factor determining the response of forests to anthropogenic climate change. Although association mapping has the potential to improve our understanding of the genomic underpinnings of climatically relevant traits, the utility of adaptive polymorphisms uncovered by such studies would be greatly enhanced by the development of integrated models that account for the phenotypic effects of multiple single-nucleotide polymorphisms (SNPs) and their interactions simultaneously. We previously reported the results of association mapping in the widespread conifer Sitka spruce (Picea sitchensis). In the current study we used the recursive partitioning algorithm 'Random Forest' to identify optimized combinations of SNPs to predict adaptive phenotypes. After adjusting for population structure, we were able to explain 37% and 30% of the phenotypic variation, respectively, in two locally adaptive traits--autumn budset timing and cold hardiness. For each trait, the leading five SNPs captured much of the phenotypic variation. To determine the role of epistasis in shaping these phenotypes, we also used a novel approach to quantify the strength and direction of pairwise interactions between SNPs and found such interactions to be common. Our results demonstrate the power of Random Forest to identify subsets of markers that are most important to climatic adaptation, and suggest that interactions among these loci may be widespread.

  11. Facilitating Oak and Hickory Regeneration in Mature Central Hardwood Forests

    Directory of Open Access Journals (Sweden)

    Eric J. Holzmueller

    2014-12-01

    Full Text Available Advanced oak and hickory regeneration is often absent in mature oak-hickory forests in the Central Hardwood Region of the United States. Prescribed fire and thinning, alone and combined, are commonly prescribed silvicultural treatments that are recommended to initiate the regeneration process. This study examined the regeneration response in three mature oak stands following four treatments: (1 thin, (2 burn, (3 thinning and burning, or (4 no treatment (control. Ten years after initial treatment, results indicate that oak and hickory seedlings had greater height and diameter in the thinning and burning treatment compared to the control and that this treatment may help facilitate desirable regeneration in mature oak-hickory forests.

  12. Are temperate mature forests buffered from invasive lianas?

    Science.gov (United States)

    Pavlovic, Noel B.; Leicht-Young, Stacey A.

    2011-01-01

    Mature and old-growth forests are often thought to be buffered against invasive species due to low levels of light and infrequent disturbance. Lianas (woody vines) and other climbing plants are also known to exhibit lower densities in older forests. As part of a larger survey of the lianas of the southern Lake Michigan region in mature and old-growth forests, the level of infestation by invasive lianas was evaluated. The only invasive liana detected in these surveys was Celastrus orbiculatus Thunb. (Celastraceae). Although this species had only attached to trees and reached the canopy in a few instances, it was present in 30% of transects surveyed, mostly as a component of the ground layer. Transects with C. orbiculatus had higher levels of soil potassium and higher liana richness than transects without. In contrast, transects with the native C. scandens had higher pH, sand content, and soil magnesium and lower organic matter compared to transects where it was absent. Celastrus orbiculatus appears to be a generalist liana since it often occurs with native lianas. Celastrus orbiculatus poses a substantial threat to mature forests as it will persist in the understory until a canopy gap or other disturbance provides the light and supports necessary for it to ascend to the canopy and damage tree species. As a result, these forests should be monitored by land managers so that C. orbiculatus eradication can occur while invasions are at low densities and restricted to the ground layer.

  13. Evaluating the Suitability of Management Strategies of Pure Norway Spruce Forests in the Black Forest Area of Southwest Germany for Adaptation to or Mitigation of Climate Change

    Science.gov (United States)

    Yousefpour, Rasoul; Hanewinkel, Marc; Le Moguédec, Gilles

    2010-02-01

    The study deals with the problem of evaluating management strategies for pure stands of Norway spruce ( Picea abies Karst) to balance adaptation to and mitigation of climate change, taking into account multiple objectives of a forest owner. A simulation and optimization approach was used to evaluate the management of a 1000 ha model Age-Class forest, representing the age-class distribution of an area of 66,000 ha of pure Norway spruce forests in the Black Forest region of Southwest Germany. Eight silvicultural scenarios comprising five forest conversion schemes which were interpreted as “adaptation” strategies which aims at increasing the proportion of Beech, that is expected to better cope with climate change than the existing Norway spruce, and three conventional strategies including a “Do-nothing” alternative classified as “mitigation”, trying to keep rather higher levels of growing stock of spruce, were simulated using the empirical growth simulator BWINPro-S. A linear programming approach was adapted to simultaneously maximize the net present values of carbon sequestration and timber production subject to the two constraints of wood even flow and partial protection of the oldest (nature protection). The optimized plan, with the global utility of 11,687 €/ha in forty years, allocated a combination of silvicultural scenarios to the entire forest area. Overall, strategies classified as “mitigation” were favored, while strategies falling into the “adaptation”-category were limited to the youngest age-classes in the optimal solution. Carbon sequestration of the “Do-nothing” alternative was between 1.72 and 1.85 million tons higher than the other alternatives for the entire forest area while the differences between the adaptation and mitigation approaches were approximately 133,000 tons. Sensitivity analysis showed that a carbon price of 21 €/ t is the threshold at which carbon sequestration is promoted, while an interest rate of above 2

  14. Fluxes of biogenic volatile organic compounds measured and modelled above a Norway spruce forest

    Science.gov (United States)

    Juráň, Stanislav; Fares, Silvano; Pallozzi, Emanuele; Guidolotti, Gabriele; Savi, Flavia; Alivernini, Alessandro; Calfapietra, Carlo; Večeřová, Kristýna; Křůmal, Kamil; Večeřa, Zbyněk; Cudlín, Pavel; Urban, Otmar

    2016-04-01

    Fluxes of biogenic volatile organic compounds (BVOCs) were investigated at Norway spruce forest at Bílý Kříž in Beskydy Mountains of the Czech Republic during the summer 2014. A proton-transfer-reaction-time-of-flight mass spectrometer (PTR-TOF-MS, Ionicon Analytik, Austria) has been coupled with eddy-covariance system. Additionally, Inverse Lagrangian Transport Model has been used to derive fluxes from concentration gradient of various monoterpenes previously absorbed into n-heptane by wet effluent diffusion denuder with consequent quantification by gas chromatography with mass spectrometry detection. Modelled data cover each one day of three years with different climatic conditions and previous precipitation patterns. Model MEGAN was run to cover all dataset with monoterpene fluxes and measured basal emission factor. Highest fluxes measured by eddy-covariance were recorded during the noon hours, represented particularly by monoterpenes and isoprene. Inverse Lagrangian Transport Model suggests most abundant monoterpene fluxes being α- and β-pinene. Principal component analysis revealed dependencies of individual monoterpene fluxes on air temperature and particularly global radiation; however, these dependencies were monoterpene specific. Relationships of monoterpene fluxes with CO2 flux and relative air humidity were found to be negative. MEGAN model correlated to eddy-covariance PTR-TOF-MS measurement evince particular differences, which will be shown and discussed. Bi-directional fluxes of oxygenated short-chain volatiles (methanol, formaldehyde, acetone, acetaldehyde, formic acid, acetic acid, methyl vinyl ketone, methacrolein, and methyl ethyl ketone) were recorded by PTR-TOF-MS. Volatiles of anthropogenic origin as benzene and toluene were likely transported from the most benzene polluted region in Europe - Ostrava city and adjacent part of Poland around Katowice, where metallurgical and coal mining industries are located. Those were accumulated during

  15. Soil evolution in spruce forest ecosystems: role and influence of humus studied by morphological approach

    Directory of Open Access Journals (Sweden)

    Chersich S

    2007-01-01

    Full Text Available In order to understand the role and the mutual influences of humus and soil in alpine spruce forest ecosystems we studied and classified 7 soil - humic profiles on the 4 main forestry dynamics: open canopy, regeneration, young stand, tree stage. We studied the role of humification process in the pedologic process involving soils and vegetations studing humic and soil horizons. Study sites are located at an altitude of 1740 m a.s.l near Pellizzano (TN, and facing to the North. The parent soil material is predominantly composed of morenic sediments, probably from Cevedale glacier lying on a substrate of tonalite from Presanella (Adamello Tertiary pluton. The soil temperature regime is frigid, while the moisture regime is udic. The characteristics observed in field were correlated with classical chemical and physical soil analyses (MIPAF 2000. In order to discriminate the dominant soil forming process, the soils were described and classified in each site according to the World Reference Base (FAO-ISRIC-ISSS 1998. Humus was described and classified using the morphological-genetic approach (Jabiol et al. 1995. The main humus forms are acid and they are for the greater part Dysmoder on PODZOLS. The main pedogenetic processes is the podzolization, locally there are also hydromorphic processes. We associate a definite humus form with a pedological process at a particular step of the forest evolution. We concluded thath the soil study for a correct pedological interpretation must take count of the characteristics of the humic epipedon.

  16. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests

    Science.gov (United States)

    Lapenis, Andrei Gennady; Lawrence, Gregory B.; Heim, Alexander; Zheng, Chengyang; Shortle, Walter

    2013-01-01

    Increased greening of northern forests, measured by the Normalized Difference Vegetation Index (NDVI), has been presented as evidence that a warmer climate has increased both net primary productivity (NPP) and the carbon sink in boreal forests. However, higher production and greener canopies may accompany changes in carbon allocation that favor foliage or fine roots over less decomposable woody biomass. Furthermore, tree core data throughout mid- and northern latitudes have revealed a divergence problem (DP), a weakening in tree ring responses to warming over the past half century that is receiving increasing attention, but remains poorly understood. Often, the same sites exhibit trend inconsistency phenomenon (TIP), namely positive, or no trends in growing season NDVI where negative trends in tree ring indexes are observed. Here we studied growth of two Norway spruce (Picea abies) stands in western Russia that exhibited both the DP and TIP but were subject to soil acidification and calcium depletion of differing timing and severity. Our results link the decline in radial growth starting in 1980 to a shift in carbon allocation from wood to roots driven by a combination of two factors: (a) soil acidification that depleted calcium and impaired root function and (b) earlier onset of the growing season that further taxed the root system. The latter change in phenology appears to act as a trigger at both sites to push trees into nutrient limitation as the demand for Ca increased with the longer growing season, thereby causing the shift in carbon allocation.

  17. Pattern recognition of spruce trees. An integrated, analytical approach to forest damage

    International Nuclear Information System (INIS)

    Simmleit, N.; Schulten, H.R.

    1989-01-01

    In-source pyrolysis-field ionization mass spectrometry was used to fingerprint old needles taken from 90-year-old Norway spruce trees (Picea abies) grown in the Taunus mountains (Federal Republic of Germany). Biometric, physiological variables and elemental compositions of needle and forest soil samples were gathered for the same trees. The mass spectral and conventional data sets were evaluated by principal-component and multiple regression analysis. The results indicate that the mass signal pattern of antioxidants, the soil acidity, the water status, and the nutritional supply of the plant contribute most to the variance of damage symptoms observed in the forest stand investigated. The visual needle loss of the canopy can be predicted by antioxidant, soil acidity, and water status parameters, whereas a further classification according to the discoloration of the needles can only be achieved by adding a soil nutrient component. It is emphasized that multivariate statistical evaluation of complex data sets should be used for the investigation of environmental problems

  18. Seedling establishment and distribution of direct radiation in slit-shaped openings of Norway spruce forests in the intermediate Alps

    International Nuclear Information System (INIS)

    Brang, P.

    1996-01-01

    Direct radiation is crucial for Norway spruce (Picea abies (L.) Karst.) seedling establishment in high-montane and subalpine spruce forests. Fisheye photography was used to estimate the daily distribution of direct radiation in small forest openings on a north-northwest and a south facing slope near Sedrun (Grisons, Switzerland). In slit-shaped openings on the north-northwest facing slope long sunflecks mostly occurred in the afternoon, when the sun shines parallel to the slit axis. This is in accordance to the silvicultural intention. However, since the stands are clumpy and therefore pervious to sunlight, the daily sunfleck distribution is fairly even notwithstanding the slit orientation, and direct radiation at noon is the dominant form of incident energy. In small circular to rectangular openings on the south facing slope direct radiation peaks at noontide. A seeding trial imitating natural seedling establishment was set in place in openings on both slopes. Based on this trial, the relations among seedling establishment, aspect, slit shape, size, and orientation are discussed for Norway spruce forests in the intermediate Alps. The directional weather factors such as radiation and precipitation can be highly influenced by slits, which is why suitable microclimate for seedling establishment can be promoted provided the slits are oriented appropriately. Slits in which the most insolated edges are oriented windward are especially favourable

  19. Moss and soil contributions to the annual net carbon flux of a maturing boreal forest

    Science.gov (United States)

    Harden, J.W.; O'Neill, K. P.; Trumbore, S.E.; Veldhuis, H.; Stocks, B.J.

    1997-01-01

    We used input and decomposition data from 14C studies of soils to determine rates of vertical accumulation of moss combined with carbon storage inventories on a sequence of burns to model how carbon accumulates in soils and moss after a stand-killing fire. We used soil drainage - moss associations and soil drainage maps of the old black spruce (OBS) site at the BOREAS northern study area (NSA) to areally weight the contributions of each moderately well drained, feathermoss areas; poorly drained sphagnum - feathermoss areas; and very poorly drained brown moss areas to the carbon storage and flux at the OBS NSA site. On this very old (117 years) complex of black spruce, sphagnum bog veneer, and fen systems we conclude that these systems are likely sequestering 0.01-0.03 kg C m-2 yr-' at OBS-NSA today. Soil drainage in boreal forests near Thompson, Manitoba, controls carbon storage and flux by controlling moss input and decomposition rates and by controlling through fire the amount and quality of carbon left after burning. On poorly drained soils rich in sphagnum moss, net accumulation and long-term storage of carbon is higher than on better drained soils colonized by feathermosses. The carbon flux of these contrasting ecosystems is best characterized by soil drainage class and stand age, where stands recently burned are net sources of CO2, and maturing stands become increasingly stronger sinks of atmospheric CO2. This approach to measuring carbon storage and flux presents a method of scaling to larger areas using soil drainage, moss cover, and stand age information.

  20. Understory Structure and Vascular Plant Diversity in Naturally Regenerated Deciduous Forests and Spruce Plantations on Similar Clear-Cuts: Implications for Forest Regeneration Strategy Selection

    Directory of Open Access Journals (Sweden)

    ZhiQiang Fang

    2014-04-01

    Full Text Available The active effect of natural regeneration on understory vegetation and diversity on clear-cut forestlands, in contrast to conifer reforestation, is still controversial. Here we investigated differences in understory vegetation by comparing naturally regenerated deciduous forests (NR and reforested spruce plantations (SP aged 20–40 years on 12 similar clear-cuts of subalpine old-growth spruce-fir forests from the eastern Tibetan Plateau. We found that 283 of the 334 vascular plant species recorded were present in NR plots, while only 264 species occurred in SP plots. This was consistent with richer species, higher cover, and stem (or shoot density of tree seedlings, shrubs, and ferns in the NR plots than in the SP plots. Moreover, understory plant diversity was limited under dense canopy cover, which occurred more frequently in the SP plots. Our findings implied that natural deciduous tree regeneration could better preserve understory vegetation and biodiversity than spruce reforestation after clear-cutting. This result further informed practices to reduce tree canopy cover for spruce plantations or to integrate natural regeneration and reforestation for clear-cuts in order to promote understory vegetation and species diversity conservation.

  1. Juvenility and serial vegetative propagation of Norway spruce clones (Picea abies Karst.).

    Science.gov (United States)

    J.B. St. Clair; J. Kleinschmit; J. Svolba

    1985-01-01

    Effects associated with progressive maturation of clones are of greatest concern in clonal tree improvement programs. Serial propagation has been in use at the Lower Saxony Forest Research Institute since 1968 to arrest maturation in Norway spruce clones. By 1980 cuttings were established in the nursery that had been serially propagated from one to five cycles. This...

  2. Effects of warming on the structure and function of a boreal black spruce forest

    Energy Technology Data Exchange (ETDEWEB)

    Stith T.Gower

    2010-03-03

    A strong argument can be made that there is a greater need to study the effect of warming on boreal forests more than on any other terrestrial biome. Boreal forests, the second largest forest biome, are predicted to experience the greatest warming of any forest biome in the world, but a process-based understanding of how warming will affect the structure and function of this economically and ecologically important forest biome is lacking. The effects of warming on species composition, canopy structure and biogeochemical cycles are likely to be complex; elucidating the underlying mechanisms will require long-term whole-ecosystem manipulation to capture all the complex feedbacks (Shaver et al. 2000, Rustad et al. 2001, Stromgren 2001). The DOE Program for Ecosystem Research funded a three year project (2002-2005) to use replicated heated chambers on soil warming plots in northern Manitoba to examine the direct effects of whole-ecosystem warming. We are nearing completion of our first growing season of measurements (fall 2004). In spite of the unforeseen difficulty of installing the heating cable, our heating and irrigation systems worked extremely well, maintaining environmental conditions within 5-10% of the specified design 99% of the time. Preliminary data from these systems, all designed and built by our laboratory at the University of Wisconsin, support our overall hypothesis that warming will increase the carbon sink strength of upland boreal black spruce forests. I request an additional three years of funding to continue addressing the original objectives: (1) Examine the effect of warming on phenology of overstory, understory and bryophyte strata. Sap flux systems and dendrometer bands, monitored by data loggers, will be used to quantify changes in phenology and water use. (2) Quantify the effects of warming on nitrogen and water use by overstory, understory and bryophytes. (3) Compare effects of warming on autotrophic respiration and above- and belowground

  3. Ozone gradients in a spruce forest stand in relation to wind speed and time of the day

    Science.gov (United States)

    Pleijel, H.; Wallin, G.; Karlsson, P. E.; Skärby, L.

    Ozone concentrations were measured outside and inside a 60-year-old 15-20 m tall spruce forest at a wind-exposed forest edge in southwest Sweden, at 3 and 13 m height 15 m outside the forest, and at 3 and 13 m height inside the forest 45 m from the forest edge. Measurements at 3 m were made with three replicate tubes on each site, the replicates being separated by 10 m. In addition, horizontal and vertical wind speeds were measured at 8 m height outside and inside the forest. During daytime, the concentrations inside the forest were generally slightly lower. Negative ozone concentration gradients from the open field into the forest were observed at 3 m height when the wind speed was below approximately 1.5 m s -1. At very low wind speeds, mainly occurring during the night, the ozone concentrations at 3 m height were frequently higher inside the forest than outside the forest. This may be caused by a very large aerodynamic resistance to ozone deposition, due to very small air movements inside the forest under stable conditions. It is concluded that ozone uptake by the trees is likely to be very small at night, even if stomata are not entirely closed. Results from open-top chamber experiments are also discussed.

  4. Drivers of variability in tree transpiration in a Boreal Black Spruce Forest Chronosequence

    Science.gov (United States)

    Angstmann, J. L.; Ewers, B. E.; Kwon, H.

    2009-12-01

    Boreal forests are of particular interest in climate change studies because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through the impact of more frequent wildfires, warmer, longer growing seasons, and potential drainage of forested wetlands. This study aims to quantify the influence of stand age, drainage condition, and species on tree transpiration and its drivers in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 113 trees (69 Picea mariana (black spruce), 25 Populus tremuloides (trembling aspen), and 19 Pinus banksiana (jack pine) at four stand ages, each containing a well- and poorly-drained site over three growing seasons (2006-2008). Sap flux per unit xylem area, JS, was expressed as transpiration per unit ground area, EC, and transpiration per unit leaf area, EL, using site- and species-specific allometry to obtain sapwood area (AS)and leaf area(AL)per unit ground area. Well-drained, younger Picea mariana daily JS was 47-64% greater than the older well-drained burn ages and younger poorly-drained stands were 64-68% greater than the two oldest poorly-drained stands. Daily EL in the well-drained Picea mariana stands was on average 12-33% higher in younger stand than in the two oldest stands whereas young, poorly-drained Picea mariana had 71% greater daily EL than the older stands. Well-drained Picea mariana trees had 52% higher daily EC than older trees and poorly-drained Picea mariana in the 1964 burn had 42-81% higher daily EC than the oldest stands. Populus tremuloides located in the two youngest stands had daily JS 38-58% greater rates than the 1930 burn, whereas daily EL and EC had no distint differences due to high interannual variability. Pinus banksiana experienced 21-33% greater daily JS in the 1989 burn than in the older 1964 burn for well- and poorly-drained sites

  5. The effects of a western spruce budworm outbreak on the dead wood component in relation to ownership in forests of eastern Oregon

    Science.gov (United States)

    David. Azuma

    2010-01-01

    Forest Inventory and Analysis data were used to investigate the effects of a severe western spruce budworm outbreak on the dead wood component of forests in 11 counties of eastern Oregon for two time periods. The ownership and the level of damage (as assessed by aerial surveys) affected the resulting down woody material and standing dead trees. The pattern of coarse...

  6. Effects of prolonged soil drought on CH4 oxidation in a temperate spruce forest

    Science.gov (United States)

    Borken, W.; Brumme, R.; Xu, Y.-J.

    2000-03-01

    Our objective was to determine potential impacts of changes in rainfall amount and distribution on soil CH4 oxidation in a temperate forest ecosystem. We constructed a roof below the canopy of a 65-year-old Norway spruce forest (Picea abies (L.) Karst.) and simulated two climate change scenarios: (1) an extensively prolonged summer drought of 172 days followed by a rewetting period of 19 days in 1993 and (2) a less intensive summer drought of 108 days followed by a rewetting period of 33 days in 1994. CH4 oxidation, soil matric potential, and soil temperature were measured hourly to daily over a 2-year period. The results showed that annual CH4 oxidation in the drought experiment increased by 102% for the climate change scenario 1 and by 41% for the climate change scenario 2, compared to those of the ambient plot (1.33 kg CH4 ha-1 in 1993 and 1.65 kg CH4 ha-1 in 1994). We tested the relationships between CH4 oxidation rates, water-filled pore space (WFPS), soil matric potential, gas diffusivity, and soil temperature. Temporal variability in the CH4 oxidation rates corresponded most closely to soil matric potential. Employing soil matric potential and soil temperature, we developed a nonlinear model for estimating CH4 oxidation rates. Modeled results were in strong agreement with the measured CH4 oxidation for the ambient (r2 = 0.80) and drought plots (r2 = 0.89) over two experimental years, suggesting that soil matric potential is a highly reliable parameter for modeling CH4 oxidation rate.

  7. Priming effects in boreal black spruce forest soils: quantitative evaluation and sensitivity analysis.

    Directory of Open Access Journals (Sweden)

    Zhaosheng Fan

    Full Text Available Laboratory studies show that introduction of fresh and easily decomposable organic carbon (OC into soil-water systems can stimulate the decomposition of soil OC (SOC via priming effects in temperate forests, shrublands, grasslands, and agro-ecosystems. However, priming effects are still not well understood in the field setting for temperate ecosystems and virtually nothing is known about priming effects (e.g., existence, frequency, and magnitude in boreal ecosystems. In this study, a coupled dissolved OC (DOC transport and microbial biomass dynamics model was developed to simultaneously simulate co-occurring hydrological, physical, and biological processes and their interactions in soil pore-water systems. The developed model was then used to examine the importance of priming effects in two black spruce forest soils, with and without underlying permafrost. Our simulations showed that priming effects were strongly controlled by the frequency and intensity of DOC input, with greater priming effects associated with greater DOC inputs. Sensitivity analyses indicated that priming effects were most sensitive to variations in the quality of SOC, followed by variations in microbial biomass dynamics (i.e., microbial death and maintenance respiration, highlighting the urgent need to better discern these key parameters in future experiments and to consider these dynamics in existing ecosystem models. Water movement carries DOC to deep soil layers that have high SOC stocks in boreal soils. Thus, greater priming effects were predicted for the site with favorable water movement than for the site with limited water flow, suggesting that priming effects might be accelerated for sites where permafrost degradation leads to the formation of dry thermokarst.

  8. Priming effects in boreal black spruce forest soils: quantitative evaluation and sensitivity analysis.

    Science.gov (United States)

    Fan, Zhaosheng; Jastrow, Julie D; Liang, Chao; Matamala, Roser; Miller, Raymond Michael

    2013-01-01

    Laboratory studies show that introduction of fresh and easily decomposable organic carbon (OC) into soil-water systems can stimulate the decomposition of soil OC (SOC) via priming effects in temperate forests, shrublands, grasslands, and agro-ecosystems. However, priming effects are still not well understood in the field setting for temperate ecosystems and virtually nothing is known about priming effects (e.g., existence, frequency, and magnitude) in boreal ecosystems. In this study, a coupled dissolved OC (DOC) transport and microbial biomass dynamics model was developed to simultaneously simulate co-occurring hydrological, physical, and biological processes and their interactions in soil pore-water systems. The developed model was then used to examine the importance of priming effects in two black spruce forest soils, with and without underlying permafrost. Our simulations showed that priming effects were strongly controlled by the frequency and intensity of DOC input, with greater priming effects associated with greater DOC inputs. Sensitivity analyses indicated that priming effects were most sensitive to variations in the quality of SOC, followed by variations in microbial biomass dynamics (i.e., microbial death and maintenance respiration), highlighting the urgent need to better discern these key parameters in future experiments and to consider these dynamics in existing ecosystem models. Water movement carries DOC to deep soil layers that have high SOC stocks in boreal soils. Thus, greater priming effects were predicted for the site with favorable water movement than for the site with limited water flow, suggesting that priming effects might be accelerated for sites where permafrost degradation leads to the formation of dry thermokarst.

  9. Searching Sinks and Sources: CO2 Fluxes Before and After Partial Deforestation of a Spruce Forest

    Science.gov (United States)

    Ney, P.; Graf, A.; Druee, C.; Esser, O.; Klosterhalfen, A.; Valler, V.; Pick, K.; Vereecken, H.

    2017-12-01

    Forest ecosystems in the northern mid-latitudes act as a sink for atmospheric carbon dioxide (CO2) and hence play an important role in the terrestrial carbon cycle. Disturbances of these landscapes may have a significant impact on their ecosystem carbon budget. We present seven years of eddy covariance (EC) measurements (September 2013 to September 2017) over a 70 year old spruce stock, including three years prior to and four years after partial deforestation. We analyzed the seasonal and inter-annual changes of carbon fluxes as affected mainly by the forest transition. The measurements were carried out in a small headwater catchment (38.5 ha) within the TERENO (TERrestrial Environmental Observatories) network in the Eifel National Park Germany (50°30'N, 06°19'E, 595-629 m a.s.l.). An EC system, mounted on the top of a 38 m high tower, continuously samples fluxes of momentum, sensible heat, latent heat and CO2. In August and September 2013, more than 20% of the catchment was deforested and planned for regeneration towards natural deciduous vegetation, and a second EC station (2.5 m height) was installed in the middle of this clearcut. Flux partitioning and gap filling methods were used to calculate full time series and annual carbon budgets of the measured net ecosystem exchange (NEE) and its components gross primary production (GPP) and total ecosystem respiration (Reco). Additionally, soil respiration was measured with manual chambers on a monthly to bi-monthly basis at 25 transect points in the forest and deforested area. Annual sums of NEE represent the forest as a carbon sink with small inter-annual variability. In contrast, the deforested area showed a clear trend. In the first year after partial deforestation, regrowth on the deforested area consisted mainly of grasses and red foxglove (Digitalis purpurea L.), while since the second year also growth of mountain ash (Sorbus aucuparia L.) and broom (Cytisus scoparius L.) increased. The regrowth of biomass is

  10. Managing Understory Vegetation for Maintaining Productivity in Black Spruce Forests: A Synthesis within a Multi-Scale Research Model

    Directory of Open Access Journals (Sweden)

    Gilles Joanisse

    2013-07-01

    Full Text Available Sustainable management of boreal ecosystems involves the establishment of vigorous tree regeneration after harvest. However, two groups of understory plants influence regeneration success in eastern boreal Canada. Ericaceous shrubs are recognized to rapidly dominate susceptible boreal sites after harvest. Such dominance reduces recruitment and causes stagnant conifer growth, lasting decades on some sites. Additionally, peat accumulation due to Sphagnum growth after harvest forces the roots of regenerating conifers out of the relatively nutrient rich and warm mineral soil into the relatively nutrient poor and cool organic layer, with drastic effects on growth. Shifts from once productive black spruce forests to ericaceous heaths or paludified forests affect forest productivity and biodiversity. Under natural disturbance dynamics, fires severe enough to substantially reduce the organic layer thickness and affect ground cover species are required to establish a productive regeneration layer on such sites. We succinctly review how understory vegetation influences black spruce ecosystem dynamics in eastern boreal Canada, and present a multi-scale research model to understand, limit the loss and restore productive and diverse ecosystems in this region. Our model integrates knowledge of plant-level mechanisms in the development of silvicultural tools to sustain productivity. Fundamental knowledge is integrated at stand, landscape, regional and provincial levels to understand the distribution and dynamics of ericaceous shrubs and paludification processes and to support tactical and strategic forest management. The model can be adapted and applied to other natural resource management problems, in other biomes.

  11. The effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate

    International Nuclear Information System (INIS)

    Jafarov, E E; Romanovsky, V E; Marchenko, S S; Genet, H; McGuire, A D

    2013-01-01

    Fire is an important factor controlling the composition and thickness of the organic layer in the black spruce forest ecosystems of interior Alaska. Fire that burns the organic layer can trigger dramatic changes in the underlying permafrost, leading to accelerated ground thawing within a relatively short time. In this study, we addressed the following questions. (1) Which factors determine post-fire ground temperature dynamics in lowland and upland black spruce forests? (2) What levels of burn severity will cause irreversible permafrost degradation in these ecosystems? We evaluated these questions in a transient modeling–sensitivity analysis framework to assess the sensitivity of permafrost to climate, burn severity, soil organic layer thickness, and soil moisture content in lowland (with thick organic layers, ∼80 cm) and upland (with thin organic layers, ∼30 cm) black spruce ecosystems. The results indicate that climate warming accompanied by fire disturbance could significantly accelerate permafrost degradation. In upland black spruce forest, permafrost could completely degrade in an 18 m soil column within 120 years of a severe fire in an unchanging climate. In contrast, in a lowland black spruce forest, permafrost is more resilient to disturbance and can persist under a combination of moderate burn severity and climate warming. (letter)

  12. Radial Growth Response of Black Spruce Stands Ten Years after Experimental Shelterwoods and Seed-Tree Cuttings in Boreal Forest

    Directory of Open Access Journals (Sweden)

    Miguel Montoro Girona

    2016-10-01

    Full Text Available Partial cutting is thought to be an alternative to achieve sustainable management in boreal forests. However, the effects of intermediate harvest intensity (45%–80% on growth remain unknown in black spruce (Picea mariana (Mill. B.S.P. stands, one of the most widely distributed boreal species with great commercial interest. In this study, we analysed the effect of three experimental shelterwood and one seed-tree treatments on tree radial growth in even-aged black spruce stands, 10 years after intervention. Our results show that radial growth response 8–10 years after cutting was 41% to 62% higher than in untreated plots, with stand structure, treatment, tree position relative to skidding trails, growth before cutting and time having significant interactions. The stand structure conditioned tree growth after cutting, being doubled in younger and denser stands. Tree spatial position had a pronounced effect on radial growth; trees at the edge of the skidding trails showed twice the increase in growth compared to interior trees. Dominant trees before cutting located close to the skidding trails manifested the highest growth response after cutting. This research suggests that the studied treatments are effective to enhance radial wood production of black spruce especially in younger stands, and that the edge effect must be considered in silvicultural management planning.

  13. Partitioning of ecosystem respiration in a paludified shallow-peat spruce forest in the southern taiga of European Russia

    International Nuclear Information System (INIS)

    Kurbatova, J; Tatarinov, F; Varlagin, A; Avilov, V; Molchanov, A; Kozlov, D; Ivanov, D; Valentini, R

    2013-01-01

    Soil, tree stems, and ecosystem carbon dioxide fluxes were measured by chambers and eddy covariance methods in a paludified shallow-peat spruce forest in the southern taiga of European Russia (Tver region, 56° N 33° E) during the growing seasons of 2002–2012. The site was established in 1998 as part of the EUROSIBERIAN CARBONFLUX project, an international field experiment examining atmosphere–biosphere interaction in Siberia and European Russia. In all years the observed annual cumulative net ecosystem flux was positive (the forest was a source of carbon to the atmosphere). Soil and tree stem respiration was a significant part of the total ecosystem respiration (ER) in this paludified shallow-peat spruce forest. On average, 49% of the ER came from soil respiration. We found that the soil fluxes exhibited high seasonal variability, ranging from 0.7 to 10 μmol m −2  s −1 . Generally, the soil respiration depended on the soil temperature and ground water level. In drought conditions, the soil respiration was low and did not depend on temperature. The stem respiration of spruces grew intensively in May, had permanently high values from June to the end of September, and in October it dramatically decreased. The tree stem respiration in midsummer was about 3–5 μmol m −2  s −1 for dominant trees and about 1–2 μmol m −2  s −1 for subdominant trees. The respiration of living tree stems was about 10–20% of the ER. (letter)

  14. Relating structural growth environment to white spruce sapling establishment at the Forest-Tundra Ecotone

    Science.gov (United States)

    Maguire, A.; Boelman, N.; Griffin, K. L.; Jensen, J.; Hiers, E.; Johnson, D. M.; Vierling, L. A.; Eitel, J.

    2017-12-01

    The effect of climate change on treeline position at the latitudinal Forest-Tundra ecotone (FTE) is poorly understood. While the FTE is expansive (stretching 13,000 km acros the panarctic), understanding relationships between climate and tree function may depend on very fine scale processes. High resolution tools are therefore needed to appropriately characterize the leading (northernmost) edge of the FTE. We hypothesized that microstructural metrics obtainable from lidar remote sensing may explain variation in the physical growth environment that governs sapling establishment. To test our hypothesis, we used terrestrial laser scanning (TLS) to collect highly spatially resolved 3-D structural information of white spruce (Picea glauca) saplings and their aboveground growth environment at the leading edge of a FTE in northern Alaska and Northwest Territories, Canada. Coordinates of sapling locations were extracted from the 3-D TLS data. Within each sampling plot, 20 sets of coordinates were randomly selected from regions where no saplings were present. Ground roughness, canopy roughness, average aspect, average slope, average curvature, wind shelter index, and wetness indexwere extracted from point clouds within a variable radius from all coordinates. Generalized linear models (GLM) were fit to determine which microstructural metrics were most strongly associated with sapling establishment. Preliminary analyses of three plots suggest that vegetation roughness, wetness index, ground roughness, and slope were the most important terrain metrics governing sapling presence (Figure 1). Comprehensive analyses will include eight plots and GLMs optimized for scale at which structural parameters affect sapling establishment. Spatial autocorrelation of sample locations will be accounted for in models. Because these analyses address how the physical growth environment affects sapling establishment, model outputs will provide information for improving understanding of the

  15. Mature oil palm plantations are thirstier than tropical forests

    Science.gov (United States)

    Manoli, G.; Meijide, A.; Huth, N.; Knohl, A.; Kosugi, Y.; Burlando, P.; Ghazoul, J.; Fatichi, S.

    2017-12-01

    Oil Palm (OP) is the highest yielding cash-crop in the world but, being the driver of significant tropical forest losses, it is also considered the "world's most hated crop". Despite substantial research on the impact of OP on ecosystem degradation, biodiversity losses, and carbon emissions, little is known on the ecohydrological impacts of forest conversion to OP. Here we employ numerical simulations constrained by field observations to quantify changes in ecosystem evapotranspiration (ET), infiltration/runoff, gross primary productivity (GPP) and surface temperature (Ts) due to OP establishment. Compared to pristine forests, young OP plantations decrease ET, causing an increase in Ts, but the changes become less pronounced as plantations grow. Mature plantations have a very high GPP to sustain the oil palm yield and, given relatively similar water use efficiency, they transpire more water that the forests they have replaced. Hence, the high fruit productivity of OP comes at the expense of water consumption. Our mechanistic modeling results corroborate anecdotal evidence of water scarcity issues in OP-dominated landscapes.

  16. Pre-outbreak forest conditions mediate the effects of spruce beetle outbreaks on fuels in subalpine forests of Colorado.

    Science.gov (United States)

    Mietkiewicz, Nathan; Kulakowski, Dominik; Veblen, Thomas T

    2018-03-01

    Over the past 30 years, forest disturbances have increased in size, intensity, and frequency globally, and are predicted to continue increasing due to climate change, potentially relaxing the constraints of vegetation properties on disturbance regimes. However, the consequences of the potentially declining importance of vegetation in determining future disturbance regimes are not well understood. Historically, bark beetles preferentially attack older trees and stands in later stages of development. However, as climate warming intensifies outbreaks by promoting growth of beetle populations and compromising tree defenses, smaller diameter trees and stands in early stages of development now are being affected by outbreaks. To date, no study has considered how stand age and other pre-outbreak forest conditions mediate the effects of outbreaks on surface and aerial fuel arrangements. We collected fuels data across a chronosequence of post-outbreak sites affected by spruce beetle (SB) between the 1940s and the 2010s, stratified by young (130 yr) post-fire stands. Canopy and surface fuel loads were calculated for each tree and stand, and available crown fuel load, crown bulk density, and canopy bulk densities were estimated. Canopy bulk density and density of live canopy individuals were reduced in all stands affected by SB, though foliage loss was proportionally greater in old stands as compared to young stands. Fine surface fuel loads in young stands were three times greater shortly (fuels decreased to below endemic (i.e., non-outbreak) levels. In both young and old stands, the net effect of SB outbreaks during the 20th and 21st centuries reduced total canopy fuels and increased stand-scale spatial heterogeneity of canopy fuels following outbreak. Importantly, the decrease in canopy fuels following outbreaks was greater in young post-fire stands than in older stands, suggesting that SB outbreaks may more substantially reduce risk of active crown fire when they affect

  17. Can we set a global threshold age to define mature forests?

    DEFF Research Database (Denmark)

    Martin, Philip; Jung, Martin; Brearley, Francis Q.

    2016-01-01

    ) whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests......Globally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used...... to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1) how climate and forest age control global forest BD and (2...

  18. Size-mediated tree transpiration along soil drainage gradients in a boreal black spruce forest wildfire chronosequence.

    Science.gov (United States)

    Angstmann, J L; Ewers, B E; Kwon, H

    2012-05-01

    Boreal forests are crucial to climate change predictions because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through more frequent wildfires, warmer, longer growing seasons and potential drainage of forested wetlands. This study aims at quantifying controls over tree transpiration with drainage condition, stand age and species in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 2007 and data were collected through 2008 on 118 trees (69 Picea mariana (Mill.) Britton, Sterns & Poggenb. (black spruce), 25 Populus tremuloides Michx. (trembling aspen), 19 Pinus banksiana Lamb. (jack pine), 3 Larix laricina (Du Roi) K. Koch (tamarack) and 2 Salix spp. (willow)) at four stand ages (18, 43, 77 and 157 years old) each containing a well- and poorly-drained stand. Transpiration estimates from sap flux were expressed per unit xylem area, J(S), per unit ground area, E(C) and per unit leaf area, E(L), using sapwood (A(S)) and leaf (A(L)) area calculated from stand- and species-specific allometry. Soil drainage differences in transpiration were variable; only the 43- and 157-year-old poorly-drained stands had ∼ 50% higher total stand E(C) than well-drained locations. Total stand E(C) tended to decrease with stand age after an initial increase between the 18- and 43-year-old stands. Soil drainage differences in transpiration were controlled primarily by short-term physiological drivers such as vapor pressure deficit and soil moisture whereas stand age differences were controlled by successional species shifts and changes in tree size (i.e., A(S)). Future predictions of boreal climate change must include stand age, species and soil drainage heterogeneity to avoid biased estimates of forest water loss and latent energy exchanges.

  19. Can we set a global threshold age to define mature forests?

    Directory of Open Access Journals (Sweden)

    Philip Martin

    2016-02-01

    Full Text Available Globally, mature forests appear to be increasing in biomass density (BD. There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1 how climate and forest age control global forest BD and (2 whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests in terms of its distribution, the climate space it occupied, and the ages of the forests used. BD increased with forest age, mean annual temperature and annual precipitation. Importantly, the effect of forest age increased with increasing temperature, but the effect of precipitation decreased with increasing temperatures. The dataset was biased towards northern hemisphere forests in relatively dry, cold climates. The dataset was also clearly biased towards forests <250 years of age. Our analysis suggests that there is not a single threshold age for forest maturity. Since climate interacts with forest age to determine BD, a threshold age at which they reach equilibrium can only be determined locally. We caution against using BD as the only determinant of forest maturity since this ignores forest biodiversity and tree size structure which may take longer to recover. Future research should address the utility and cost-effectiveness of different methods for determining whether forests should be classified as mature.

  20. Fine and coarse root parameters from mature black spruce displaying genetic x soil moisture interaction in growth

    Science.gov (United States)

    John E. Major; Kurt H. Johnsen; Debby C. Barsi; Moira Campbell

    2012-01-01

    Fine and coarse root biomass, C, and N mass parameters were assessed by root size and soil depths from soil cores in plots of 32-year-old black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) from four full-sib families studied previously for drought tolerance and differential productivity on a dry and wet...

  1. Photosynthesis and carbon isotope discrimination in boreal forest ecosystems: A comparison of functional characteristics in plants from three mature forest types

    Science.gov (United States)

    Flanagan, Lawrence B.; Brooks, J. Renee; Ehleringer, James R.

    1997-12-01

    In this paper we compare measurements of photosynthesis and carbon isotope discrimination characteristics among plants from three mature boreal forest types (Black spruce, Jack pine, and aspen) in order to help explain variation in ecosystem-level gas exchange processes. Measurements were made at the southern study area (SSA) and northern study area (NSA) of the boreal forest in central Canada as part of the Boreal Ecosystem-Atmosphere Study (BOREAS). In both the NSA and the SSA there were significant differences in photosynthesis among the major tree species, with aspen having the highest CO2 assimilation rates and spruce the lowest. Within a species, photosynthetic rates in the SSA were approximately twice those measured in the NSA, and this was correlated with similar variations in stomatal conductance. Calculations of the ratio of leaf intercellular to ambient CO2 concentration (ci/ca) from leaf carbon isotope discrimination (Δ) values indicated a relatively low degree of stomatal limitation of photosynthesis, despite the low absolute values of stomatal conductance in these boreal tree species. Within each ecosystem, leaf Δ values were strongly correlated with life-form groups (trees, shrubs, forbs, and mosses), and these differences are maintained between years. Although we observed significant variation in the 13C content of tree rings at the old Jack pine site in the NSA during the past decade (indicating interannual variation in the degree of stomatal limitation), changes in summer precipitation and temperature accounted for only 44% of the isotopic variance. We scaled leaf-level processes to the ecosystem level through analyses of well-mixed canopy air. On average, all three forest types had similar ecosystem-level Δ values (average value ± standard deviation, 19.1‰±0.5‰), calculated from measurements of change in the concentration and carbon isotope ratio of atmospheric CO2 during a diurnal cycle within a forest canopy. However, there were

  2. Environmental equity and the conservation of unique ecosystems: an analysis of the distribution of benefits for protecting Southern Appalachian spruce-fir forests

    Science.gov (United States)

    Joseph E. Aldy; Randall A. Kramer; Thomas P. Holmes

    1999-01-01

    Some critics in the environmental equity literature argue that low-income populations disproportionately have environmental risks, while the wealthy and better educated gain disproportionately from protecting unique ecosystems. The authors test this hypothesis in an analysis of the decline of Southern Appalachian spruce-fir forests. They calculate willingness-to-pay...

  3. Life-history traits maintain the genomic integrity of sympatric species of the spruce budworm (Choristoneura fumiferana) group on an isolated forest island

    Science.gov (United States)

    Lisa M. Lumley; Felix A.H. Sperling

    2011-01-01

    Identification of widespread species collected from islands can be challenging due to the potential for local ecological and phenotypic divergence in isolated populations. We sought to determine how many species of the spruce budworm (Choristoneura fumiferana) complex reside in Cypress Hills, an isolated remnant coniferous forest in western Canada....

  4. Recovery of carbon pools a decade after wildfire in black spruce forests of interior Alaska: effects of soil texture and landscape position

    Science.gov (United States)

    Gregory P. Houle; Evan S. Kane; Eric S. Kasischke; Carolyn M. Gibson; Merritt R. Turetsky

    2017-01-01

    We measured organic-layer (OL) recovery and carbon stocks in dead woody debris a decade after wildfire in black spruce (Picea mariana (Mill.) B.S.P.) forests of interior Alaska. Previous study at these research plots has shown the strong role that landscape position plays in governing the proportion of OL consumed during fire and revegetation after...

  5. Derivation of canopy resistance for water vapour fluxes over a spruce forest, using a new technique for the viscous sublayer resistance

    DEFF Research Database (Denmark)

    Jensen, N.O.; Hummelshøj, P.

    1995-01-01

    The paper reports on some evaporation measurements made above a spruce forest (Picea abies) during late August and the beginning of September 1991. The period was dry, and the response of the trees to this condition is clearly seen in the form of the diurnal course of the evapotranspiration...

  6. The effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate

    Science.gov (United States)

    E.E. Jafarov; V.E. Romanovsky; H. Genet; A.D. McGuire; S.S. Marchenko

    2013-01-01

    Fire is an important factor controlling the composition and thickness of the organic layer in the black spruce forest ecosystems of interior Alaska. Fire that burns the organic layer can trigger dramatic changes in the underlying permafrost, leading to accelerated ground thawing within a relatively short time. In this study, we addressed the following questions. (1)...

  7. Aerodynamic parameter changes above a young spruce forest stand during five growing seasons

    Czech Academy of Sciences Publication Activity Database

    Hurtalová, T.; Matejka, F.; Rožnovský, J.; Marková, Irena; Janouš, Dalibor

    2004-01-01

    Roč. 34, č. 2 (2004), s. 131-146 ISSN 1335-2806 R&D Projects: GA ČR(CZ) GA526/00/0485 Keywords : aerodynamic parameters * roughness length * young spruce stand Subject RIV: DG - Athmosphere Sciences, Meteorology

  8. Comparison of different ground techniques to map leaf area index of Norway spruce forest canopy

    NARCIS (Netherlands)

    Homolova, L.; Malenovsky, Z.; Hanus, J.; Tomaskova, I.; Dvoráková, M.; Pokorny, R.

    2007-01-01

    The leaf area index (LAI) of three monocultures of Norway spruce (Picea abies (L.) Karst), different in age and structure, was measured by means of two indirect optical techniques of LAI field mapping: 1/ plant canopy analyser LAI-2000, and 2/ digital hemispherical photographs (DHP). The supportive

  9. Communities of oribatid mites (Acari: Oribatida) of naturally regenerating and salvage-logged montane spruce forests of Šumava Mountains

    Czech Academy of Sciences Publication Activity Database

    Kokořová, Petra; Starý, Josef

    2017-01-01

    Roč. 72, č. 4 (2017), s. 445-451 ISSN 0006-3088 R&D Projects: GA ČR(CZ) GAP504/12/1218 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : oribatid mites * spruce forest * community * bark beetle gradation * forest management Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 0.759, year: 2016

  10. Experimental soil warming effects on CO2 and CH4 flux from a low elevation spruce-fir forest soil in Maine, USA

    Science.gov (United States)

    Lindsey E. Rustad; Ivan J. Fernandez

    1998-01-01

    The effect of soil warming on CO2 and CH4 flux from a spruce-fir forest soil was evaluated at the Howland Integrated Forest Study site in Maine, USA from 1993 to 1995. Elevated soil temperatures (~5 °C) were maintained during the snow-free season (May-November) in replicated 15 × 15-m plots using electric cables buried 1-2...

  11. Epiphytic bromeliad communities in secondary and mature forest in a tropical premontane area

    NARCIS (Netherlands)

    Cascante Marin, A.M.; Wolf, J.H.D.; Oostermeijer, J.G.B.; den Nijs, J.C.M.; Sanahuja, O.; Duran Apuy, A.

    2006-01-01

    We analyzed the differences in species richness, community composition, population structure and within-tree location of epiphytic bromeliads in contiguous secondary and mature forests in a premontane area in Costa Rica. Diversity in the mature forest was highest, and the communities differed in

  12. Age and size effects on seed productivity of northern black spruce

    Science.gov (United States)

    J. N. Viglas; C. D. Brown; J. F. Johnstone

    2013-01-01

    Slow-growing conifers of the northern boreal forest may require several decades to reach reproductive maturity, making them vulnerable to increases in disturbance frequency. Here, we examine the relationship between stand age and seed productivity of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) in Yukon Territory and Alaska....

  13. SOIL CO2 EFFLUX FROM ISOTOPICALLY LABELED BEECH AND SPRUCE IN SOUTHERN GERMANY

    Science.gov (United States)

    • Carbon acquisition and transport to roots in forest trees is difficult to quantify and is affected by a number of factors, including micrometeorology and anthropogenic stresses. The canopies of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) were expose...

  14. A comparison of Alpine emissions to forest soil and spruce needle loads for persistent organic pollutants (POPs)

    Energy Technology Data Exchange (ETDEWEB)

    Belis, C.A., E-mail: claudio.belis@jrc.ec.europa.e [Regional Agency for Environmental Protection of Lombardia (Italy); Offenthaler, I.; Uhl, M.; Nurmi-Legat, J. [Umweltbundesamt GmbH (Austria); Bassan, R. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Jakobi, G.; Kirchner, M. [Helmholtz Zentrum Muenchen, German Research Centre for Environment and Health (Germany); Knoth, W. [German Federal Environmental Agency (Germany); Kraeuchi, N. [WSL Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Levy, W. [Helmholtz Zentrum Muenchen, German Research Centre for Environment and Health (Germany); Magnani, T. [Regional Agency for Environmental Protection of Lombardia (Italy); Moche, W. [Umweltbundesamt GmbH (Austria); Schramm, K.-W. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Simoncic, P. [Slovenian Forestry Institute (Slovenia); Weiss, P. [Umweltbundesamt GmbH (Austria)

    2009-12-15

    The project MONARPOP analysed the concentrations of semivolatile organic compounds (SVOCs) in two important sink compartments, needles of Norway spruce (Picea abies [L.] Karst.) and forest soil from 40 remote Alpine forest sites in Austria, Germany, Italy, Slovenia and Switzerland. In the present study the load of PCDD/F, PCB, PBDE, PAH, HCB, HCH and DDT in the Alps calculated on the basis of measured data are compared with their estimated emissions in the Alpine region. It comes out that the masses of the studied pollutants stored in the forests are higher than the corresponding emissions in the Alpine area indicating that the Alps are a sink for POPs advected from surrounding areas. It is assumed that local emissions of PCDD/F and PAH deriving from biomass burning are probably underestimated and that the pool of these pollutants in the forests represents the accumulation over some decades. - The loads of POPs in the Alps are higher than their emissions in the Alpine region.

  15. Influence of road salting on the adjacent Norway spruce (Picea abies) forest

    International Nuclear Information System (INIS)

    Forczek, S.T.; Benada, O.; Kofronova, O.; Sigler, K.; Matucha, M.

    2011-01-01

    Winter deicing and traffic spreads salt to road-adjacent Norway spruce trees in the form of spraying and salt slops. Our use of Na36Cl revealed roots as the main pathway of salt uptake. One-shot application of a concentrated Na36Cl solution to spruce saplings by both irrigation and spraying causes macroscopic damage to the needles and affects the needle phyllosphere. Irrigation affects the trees more than spraying because Cl uptake through roots is faster and eventually leads to higher chloride content in the plant. Along with the root-needle route, spray-deposited chloride from the needles is re-transported back into the soil and again taken up by roots to needles

  16. Shoot water relations of mature black spruce families displaying a genotype × environment interaction in growth rate. III. Diurnal patterns as influenced by vapor pressure deficit and internal water status

    Science.gov (United States)

    John E. Major; Kurt H. Johnsen

    2001-01-01

    Pressure­volume curves were constructed and shoot water potentials measured for +20-year-old black spruce (Picea mariana (Mill.) BSP) trees from four full-sib families growing on a moist site and a dry site at the Petawawa Research Forest, Ontario, to determine whether differences in diurnal water relations traits were related to productivity. To...

  17. Comparison of different ground techniques to map leaf area index of Norway spruce forest canopy

    OpenAIRE

    Homolova, L.; Malenovsky, Z.; Hanus, J.; Tomaskova, I.; Dvoráková, M.; Pokorny, R.

    2007-01-01

    The leaf area index (LAI) of three monocultures of Norway spruce (Picea abies (L.) Karst), different in age and structure, was measured by means of two indirect optical techniques of LAI field mapping: 1/ plant canopy analyser LAI-2000, and 2/ digital hemispherical photographs (DHP). The supportive measurements with the TRAC instrument were conducted to produce mainly the element clumping index. The aim of the study was to compare the performances of LAI-2000 and DHP and to evaluate effect of...

  18. The influence of climate change on stomatal ozone flux to a mountain Norway spruce forest

    Czech Academy of Sciences Publication Activity Database

    Zapletal, M.; Pretel, J.; Chroust, P.; Cudlín, Pavel; Edwards-Jonášová, Magda; Urban, Otmar; Pokorný, Radek; Czerný, Radek; Hůnová, I.

    2012-01-01

    Roč. 169, OCT 2012 (2012), s. 267-273 ISSN 0269-7491 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk OC10022; GA MŠk(CZ) LM2010007 Institutional research plan: CEZ:AV0Z60870520 Keywords : Stomatal ozone flux * AOT40 * Phytotoxic Ozone Dose * Norway spruce * Net ecosystem production * Ozone * Climate change Subject RIV: EH - Ecology, Behaviour Impact factor: 3.730, year: 2012

  19. Oxyfluorfen safe to use engelmann spruce seedbeds. Forest Service research note

    Energy Technology Data Exchange (ETDEWEB)

    Sloan, J.P.

    1993-06-01

    Oxyfluorfen, a diphenylether herbicide, can be applied to Engelmann spruce nursery beds without significant damage to seedlings. Oxyfluorfen, applied at 0.5 lb/acre with preemergence timing for two years, reduced seedling dry mass. When the rate of herbicide application was reduced, the timing was delayed, or the applications were discontinued the second year, there was little damage to seedlings. Five of 10 herbicide treatments significantly reduced seedling densities compared to the no-treatment plots.

  20. Migration of 134,137Cs radionuclides in the soil and uptake by plants in German spruce forests

    International Nuclear Information System (INIS)

    Buermann, W.; Drissner, J.; Miller, R.; Heider, R.; Lindner, G.; Zibold, G.; Sykowa, T.

    1994-01-01

    In southern German spruce forests on different geological substrates the depth distributions of the activity inventories of 134 Cs and 137 Cs radionuclides from Chernobyl and nuclear weapons testing fallout and the corresponding activity concentrations in the dry mass of different plants were measured. Using a compartment model based on first order kinetics, the vertical residence half-times and migration rates of 137 Cs were calculated. Migration rates decrease with increasing soil depth and retention time of the 137 Cs radionuclides in the soil. The aggregated soil to plant transfer factors [m 2 /kg] on the other hand, are comparatively high: Up to 1.1 m 2 /kg for fern, and smaller values for bilberry and raspberry. It is suggested that a fixation of cesium radionuclides in the organic matter of the litter debris occurs and that the transfer to plants is mediated by carrier substances produced by microorganisms responsible for the degradation of the litter. (orig.)

  1. Influence of fertilizing on the 137Cs soil-plant transfer in a spruce forest of Southern Germany

    International Nuclear Information System (INIS)

    Zibold, G.; Klemt, E.; Konopleva, I.; Konoplev, A.

    2009-01-01

    Fertilization with 2.5 t/ha limestone: (83% CaCO 3 , 8% MgO, 6% K 2 O, 3% P 2 O 5 ) reduces the 137 Cs transfer from spruce forest soil into plants like fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus) by a factor of 2-5 during at least 11 years as measured by the aggregated transfer factor T ag . In 1997 and 2006 these results were confirmed by additional measurements of the 137 Cs transfer factor TF, related to the root zone (O h horizon), which were explained by the selective sorption of 137 Cs in the root zone by measurements of the Radiocaesium Interception Potential (RIP) in fertilized (RIP > 179 meq/kg) and non-fertilized soils (RIP < 74 meq/kg).

  2. A Tale of Two Forests: Simulating Contrasting Lodgepole Pine and Spruce Forest Water and Carbon Fluxes Following Mortality from Bark Beetles

    Science.gov (United States)

    Ewers, B. E.; Peckham, S. D.; Mackay, D. S.; Pendall, E.; Frank, J. M.; Massman, W. J.; Reed, D. E.; Borkhuu, B.

    2014-12-01

    In recent decades, bark beetle infestation in western North America has reached epidemic levels. The resulting widespread forest mortality may have profound effects on present and future water and carbon cycling with potential negative consequences to a region that relies on water from montane and subalpine watersheds. We simulated stand-level ecosystem fluxes of water and carbon at two bark beetle-attacked conifer forests in southeast Wyoming, USA. The lower elevation site dominated by lodgepole pine (Pinus contorta) was attacked by mountain pine beetle (Dendroctonus ponderosae) during 2008-2010. The high elevation Engelmann spruce (Picea engelmannii) dominated site was attacked by the spruce beetle (Dendroctonus rufipennis) during roughly the same time period. Both beetle infestations resulted in >60% canopy mortality in the footprint of eddy covariance towers located at each site. However, carbon and water fluxes responses to mortality depended on the forest type. Using data collected at the sites, we scaled simulated plant hydraulic conductivity by either percent canopy mortality or loss of live tree basal area during infestation. We also simulated a case of no beetle attack. At the lodgepole site, the no-beetle model best fit the data and showed no significant change in growing season carbon flux and a 15% decrease in evapotranspiration (ET). However, at the spruce site, the simulation that tracked canopy loss agreed best with observations: carbon flux decreased by 72% and ET decreased by 31%. In the lodgepole stand, simulated soil water content agreed with spatially distributed measurements that were weighted to reflect overall mortality in the tower footprint. Although these two forest ecosystems are only 20 km apart, separated by less than 300m in elevation, and have been impacted by similar mortality agents, the associated changes in carbon and water cycling are significantly different. Beetle effects on hydrologic cycling were greatest at high elevation

  3. Multi-Cohort Stand Structural Classification: Ground- and LiDAR-based Approaches for Boreal Mixedwood and Black Spruce Forest Types of Northeastern Ontario

    Science.gov (United States)

    Kuttner, Benjamin George

    Natural fire return intervals are relatively long in eastern Canadian boreal forests and often allow for the development of stands with multiple, successive cohorts of trees. Multi-cohort forest management (MCM) provides a strategy to maintain such multi-cohort stands that focuses on three broad phases of increasingly complex, post-fire stand development, termed "cohorts", and recommends different silvicultural approaches be applied to emulate different cohort types. Previous research on structural cohort typing has relied upon primarily subjective classification methods; in this thesis, I develop more comprehensive and objective methods for three common boreal mixedwood and black spruce forest types in northeastern Ontario. Additionally, I examine relationships between cohort types and stand age, productivity, and disturbance history and the utility of airborne LiDAR to retrieve ground-based classifications and to extend structural cohort typing from plot- to stand-levels. In both mixedwood and black spruce forest types, stand age and age-related deadwood features varied systematically with cohort classes in support of an age-based interpretation of increasing cohort complexity. However, correlations of stand age with cohort classes were surprisingly weak. Differences in site productivity had a significant effect on the accrual of increasingly complex multi-cohort stand structure in both forest types, especially in black spruce stands. The effects of past harvesting in predictive models of class membership were only significant when considered in isolation of age. As an age-emulation strategy, the three cohort model appeared to be poorly suited to black spruce forests where the accrual of structural complexity appeared to be more a function of site productivity than age. Airborne LiDAR data appear to be particularly useful in recovering plot-based cohort types and extending them to the stand-level. The main gradients of structural variability detected using Li

  4. Impact of soil drainage to the radial stem growth of Norway spruce (Picea Abies L. Karst. in peatland forests

    Directory of Open Access Journals (Sweden)

    Klempířová Barbora

    2013-12-01

    Full Text Available Peatland Norway spruce (Picea abies L. Karst. forests represent very valuable ecosystems with considerable importance for nature conservation. However, a lot of peatland forests have been drained or used for opencast mining of peat. Since dendrochronological and dendroecological studies on trees growing on peatlands in Europe are not many, this study aimed to reconstruct the impact of drainage to the growth of trees in forest stands older than 100 years in the moment of drainage. Dendrochronological analysis was performed on two 0.25-ha square sampling plots (50*50 m in two pre-selected stands (control site vs. drained site with similar natural conditions and age. The mean-value functions of the ring indices, comparing the drained site with the control site, in the period after 1940 revealed very similar radial-growth trends. After the year 1992, when one site was substantially drained, the radial-growth trends not showed any significant change. Likewise, the result of the independent two sample t-test for the period after 1992 has not revealed any substantial statistically important difference in the mean index between the control site and the drained site.

  5. Variation in carbohydrate source-sink relations of forest and treeline white spruce in southern, interior and northern Alaska.

    Science.gov (United States)

    Sveinbjörnsson, Bjartmar; Smith, Matthew; Traustason, Tumi; Ruess, Roger W; Sullivan, Patrick F

    2010-08-01

    Two opposing hypotheses have been presented to explain reduced tree growth at the treeline, compared with growth in lower elevation or lower latitude forests: the carbon source and sink limitation hypotheses. The former states that treeline trees have an unfavorable carbon balance and cannot support growth of the magnitude observed at lower elevations or latitudes, while the latter argues that treeline trees have an adequate carbon supply, but that cold temperatures directly limit growth. In this study, we examined the relative importance of source and sink limitation in forest and treeline white spruce (Picea glauca) in three mountain ranges from southern to northern Alaska. We related seasonal changes in needle nonstructural carbohydrate (NSC) content with branch extension growth, an approach we argue is more powerful than using needle NSC concentration. Branch extension growth in the southernmost Chugach Mountains was much greater than in the White Mountains and the Brooks Range. Trees in the Chugach Mountains showed a greater seasonal decline in needle NSC content than trees in the other mountain ranges, and the seasonal change in NSC was correlated with site-level branch growth across mountain ranges. There was no evidence of a consistent difference in branch growth between the forest and treeline sites, which differ in elevation by approximately 100 m. Our results point to a continuum between source and sink limitation of growth, with high-elevation trees in northern and interior Alaska showing greater evidence of sink limitation, and those in southern Alaska showing greater potential for source limitation.

  6. Nitrogen availability in Norway spruce forest floor – the effect of forest defoliation induced by bark beetle infestation

    Czech Academy of Sciences Publication Activity Database

    Tahovská, K.; Kopáček, Jiří; Šantrůčková, H.

    2010-01-01

    Roč. 15, č. 6 (2010), 553–564. ISSN 1239-6095 R&D Projects: GA ČR(CZ) GA206/07/1200; GA AV ČR(CZ) KJB600960907 Grant - others:FM EHS(CZ) CZ-0051 Institutional research plan: CEZ:AV0Z60170517 Keywords : nitrogen availability * Norway spruce * soil Subject RIV: GK - Forestry Impact factor: 1.296, year: 2010

  7. Response of Nitrogen Leaching to Nitrogen Deposition in Disturbed and Mature Forests of Southern China

    Institute of Scientific and Technical Information of China (English)

    FANG Yun-Ting; M. YOH; MO Jiang-Ming; P. GUNDERSEN; ZHOU Guo-Yi

    2009-01-01

    Current nitrogen (N) leaching losses and their responses to monthly N additions were investigated under a disturbed pine (Pinus massoniana) forest and a mature monsoon broadleaf forest in southern China. N leaching losses from both disturbed and mature forests were quite high (14.6 and 29.2 kg N ha-1 year-1, respectively), accounting for 57% and 80% of their corresponding atmospheric N inputs. N leaching losses were substantially increased following the first 1.5 years of N applications in both forests. The average increases induced by the addition of 50 and 100 kg N ha-1 year-1 were 36.5 and 24.9 kg N ha-1 year-1, respectively, in the mature forest, accounting for 73.0% and 24.9% of the annual amount of N added, and 14.2 and 16.8 kg N ha-1 year-1 in the disturbed forest, accounting for 28.4% and 16.8% of the added N. Great N leaching and a fast N leaching response to N additions in the mature forest might result from long-term N accumulation and high ambient N deposition load (greater than 30 kg N ha-1 year-1 over the past 15 years), whereas in the disturbed forest, it might result from the human disturbance and high ambient N deposition load. These results suggest that both disturbed and mature forests in the study region may be sensitive to increasing N deposition.

  8. Carbon and Nitrogen Pools and Fluxes in Adjacent Mature Norway Spruce and European Beech Forests

    Czech Academy of Sciences Publication Activity Database

    Oulehle, Filip; Růžek, M.; Tahovská, K.; Bárta, J.; Myška, O.

    2016-01-01

    Roč. 7, č. 11 (2016), č. článku 282. ISSN 1999-4907 Institutional support: RVO:67179843 Keywords : Fagus sylvatica * Picea abies * carbon * nitrogen * budget * respiration * productivity Subject RIV: EH - Ecology, Behaviour Impact factor: 1.951, year: 2016

  9. Variation in Wood Quality in White Spruce (Picea Glauca (Moench Voss. Part I. Defining the Juvenile–Mature Wood Transition Based on Tracheid Length

    Directory of Open Access Journals (Sweden)

    Cyriac Serge Mvolo

    2015-01-01

    Full Text Available Estimations of transition age (TA and juvenile wood proportion (JWP are important for wood industries due to their impact on end-product quality. However, the relationships between analytical determination of TA based on tracheid length (TL and recognized thresholds for adequate end products have not yet been established. In this study, we used three different statistical models to estimate TA in white spruce (Picea glauca (Moench Voss based on TL radial variation. We compared the results with technological maturity. A two-millimeter threshold, previously suggested for good paper tear strength, was used. Tracheid length increased from pith to bark and from breast height to upper height. Juvenile wood (JW was conical with the three models. At breast height, TA ranged from 11 to 27 years and JWP ranged from 15.3% to 47.5% across the three models. The linear mixed model produced more conservative estimates than the maximum-quadratic-linear (M_Q_L model. Both the linear mixed model and the M_Q_L model produced more conservative TA estimates than the piecewise model. TA estimates by the MIXED model, and to a lesser extent by the M_Q_L model, were equivalent to those for real mature wood, whereas TA estimates by the piecewise model were considerably lower, falling into the transition wood area.

  10. Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass.

    Science.gov (United States)

    Liu, YingChun; Yu, GuiRui; Wang, QiuFeng; Zhang, YangJian; Xu, ZeHong

    2014-12-01

    Forests play an important role in acting as a carbon sink of terrestrial ecosystem. Although global forests have huge carbon carrying capacity (CCC) and carbon sequestration potential (CSP), there were few quantification reports on Chinese forests. We collected and compiled a forest biomass dataset of China, a total of 5841 sites, based on forest inventory and literature search results. From the dataset we extracted 338 sites with forests aged over 80 years, a threshold for defining mature forest, to establish the mature forest biomass dataset. After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors, we used carbon density of mature forests as the reference level, and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging, Inverse Distance Weighted and Partial Thin Plate Smoothing Spline. Combining with the sixth National Forest Resources Inventory, we also estimated the forest CSP. The results revealed positive relationships between carbon density of mature forests and temperature, precipitation and stand age, and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation. The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C, respectively. Subtropical forests would have more CCC and CSP than other biomes. Consequently, relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.

  11. Norway spruce (Picea abies/L./Karst.) health status on various forest soil ecological series in Silesian Beskids obtained by grid or selective survey

    Czech Academy of Sciences Publication Activity Database

    Samec, Pavel; Edwards-Jonášová, Magda; Cudlín, Pavel

    2017-01-01

    Roč. 10, 1-2 (2017), s. 57-66 ISSN 1803-2451 R&D Projects: GA MŠk LD15044; GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : spruce decline * survey design * defoliation * forest site ecological series Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) https://beskydy.mendelu.cz/10/1/0057/

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

    Science.gov (United States)

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

    2015-09-01

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

  13. Effects of climate change on fire and spruce budworm disturbance regimes and consequences on forest biomass production in eastern Canada

    International Nuclear Information System (INIS)

    Gauthier, S.

    2004-01-01

    The dynamics of spruce budworm (SBW) outbreaks and wildfires are expected to change as climatic change progresses. The effects of an altered, combined interaction between SBW and fire may be of greater importance than the individual effect of either on forest biomass production. The objectives of this study are to define current fire and SBW regimes in eastern Canada and relate the characteristics of each regime based upon climate model outputs for 2050 and 2100. The study also attempts to evaluate the impact of predicted changes in SBW and fire disturbance regimes on forest dynamics. The methodology used in the study included data from the Canadian Large Fire Database and historical records of SBW outbreaks. Spatial and environmental variables were presented along with climate models. The analysis was conducted using constrained ordination techniques, and canonical correspondence and redundancy analysis. Projected disturbance regimes were presented for both fire and SBW. The effects of the regimes on biomass productivity were also examined, using a Landscape Disturbance Simulator (LAD). It was concluded that this model will help evaluate the consequences of changes imposed by climatic change on both disturbances individually, as well as their interaction. 10 refs., 1 tab., 2 figs

  14. Concentrations of dissolved organic carbon along an altitudinal gradient from Norway spruce forest to the mountain birch/alpine ecotone in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, N.; Roesberg, I.; Aamlid, D.

    2005-07-01

    Concentrations of dissolved organic carbon (DOC) in soil water from the base of the soil organic layer were determined at three forest plots along an altitudinal gradient in eastern Norway. The lowest plot, at 830 m above sea level (a.s.l.), was in Norway spruce forest and there were additional plots at the ecotone between Norway spruce and mountain birch at 925 m a.s.l. and at the forest line (1000 m a.s.l.). DOC concentrations in soil water did not decrease uniformly with altitude although tree biomass, above-ground litterfall and the soil C pool all did so. Significant correlations between DOC and (H{sup +}) or electrical conductivity may reflect the contribution of DOC to solution acidity and the anionic charge, respectively. If mean temperature during the growing season increases, tree growth at any given altitude will tend to increase and the spruce-birch ecotone may move to a higher altitude than at present. Increased C inputs as litter to the soil might then lead to increasing DOC concentrations and fluxes in surface waters. (orig.)

  15. Regeneration of Mature Norway Spruce Stands: Early Effects of Selective Cutting and Clear Cutting on Seepage Water Quality and Soil Fertility

    Directory of Open Access Journals (Sweden)

    Wendelin Weis

    2001-01-01

    Full Text Available The cutting of trees influences element turnover in the forest ecosystem. The reduction of plant uptake, as well as an increased mineralization and nitrification due to higher soil temperature and soil moisture, can lead to considerable losses of nutrients from the main rooting zone. This may result in a reduced soil fertility and a decrease in drinking water quality due to high nitrate concentrations in the seepage water. In Bavaria (Germany selective cutting is preferred to clear cutting when initiating the regeneration of Norway spruce stands with European beech. This paper summarizes the early effects of both forest management practices on soil fertility and seepage water quality for three different sites. Shown are the concentrations of nitrogen and base cations in the seepage water as well as the water and ion fluxes during the first year after tree cut. Nutrient inputs decreased on thinned plots and even more at clear-cuts. Nitrate concentrations in the seepage water are hardly affected by moderate thinning; however, on clear-cuts, the nitrate concentration increases significantly, and base cations are lost from the upper mineral soil. This effect is less obvious at sites where a dense ground vegetation, which is able to take up excess nitrogen, exists.

  16. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Directory of Open Access Journals (Sweden)

    Guohua Liang

    Full Text Available The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF, a transitional mixed conifer and broadleaf forest (MF and an old-growth broadleaved forest (BF] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0. Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  17. Response of soil respiration to acid rain in forests of different maturity in southern China.

    Science.gov (United States)

    Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  18. CS-137 transfer factors soil-plant and density of hyphae in soil of spruce forests

    International Nuclear Information System (INIS)

    Klemt, E.; Deuss, H.; Drissner, J.; Krapf, M.; Miller, R.; Zibold, G.

    1999-01-01

    Samples of soil and plants were taken at spruce stand sites in southern Baden-Wuerttemberg. Fern always had the highest aggregated Cs-137 transfer factor (T ag ) varying between 0.01 and 0.27 m 2 kg -1 . There is a tendency for higher T ag s in soils with thicker raw humus layers, lower pH, lower cation exchange capacity (CEC) in the O h horizon, and lower clay content below the organic deposit. The density of hyphae is determined by the season and its weather conditions and it usually decreases continuously from O f to top B horizon. In analyzing our data no correlation between aggregated or horizon-specific transfer factors of different plants and density of hyphae could be found. Refs. 5 (author)

  19. Seasonal changes in camera-based indices from an open canopy black spruce forest in Alaska, and comparison with indices from a closed canopy evergreen coniferous forest in Japan

    Science.gov (United States)

    Nagai, Shin; Nakai, Taro; Saitoh, Taku M.; Busey, Robert C.; Kobayashi, Hideki; Suzuki, Rikie; Muraoka, Hiroyuki; Kim, Yongwon

    2013-06-01

    Evaluation of the carbon, water, and energy balances in evergreen coniferous forests requires accurate in situ and satellite data regarding their spatio-temporal dynamics. Daily digital camera images can be used to determine the relationships among phenology, gross primary productivity (GPP), and meteorological parameters, and to ground-truth satellite observations. In this study, we examine the relationship between seasonal variations in camera-based canopy surface indices and eddy-covariance-based GPP derived from field studies in an Alaskan open canopy black spruce forest and in a Japanese closed canopy cedar forest. The ratio of the green digital number to the total digital number, hue, and GPP showed a bell-shaped seasonal profile at both sites. Canopy surface images for the black spruce forest and cedar forest mainly detected seasonal changes in vegetation on the floor of the forest and in the tree canopy, respectively. In contrast, the seasonal cycles of the ratios of the red and blue digital numbers to the total digital numbers differed between the two sites, possibly due to differences in forest structure and leaf color. These results suggest that forest structural characteristics, such as canopy openness and seasonal forest-floor changes, should be considered during continuous observations of phenology in evergreen coniferous forests.

  20. Sphagnum mosses limit total carbon consumption during fire in Alaskan black spruce forests

    Science.gov (United States)

    G. Shetler; .R. Turetsky; E. Kane; E. Kasischke

    2008-01-01

    The high water retention of hummock-forming Sphagnum species minimizes soil moisture fluctuations and might protect forest floor organic matter from burning during wildfire. We hypothesized that Sphagnum cover reduces overall forest floor organic matter consumption during wildfire compared with other ground-layer vegetation. We...

  1. Elemental cycling response of an Adirondack subalpine spruce-fir forest to atmospheric and environmental change

    Science.gov (United States)

    Andrew J. Friedland; Eric K. Miller

    1996-01-01

    Patterns and trends in forest elemental cycling can become more apparent in the presence of atmospheric perturbations. High-elevation forests of the northeastern United States have received large amounts of atmospheric deposition of pollutants, which have altered natural elemental cycling and retention rates in a variety of ways. This study examined atmospheric...

  2. The effects of acid irrigation and compensation liming on soil and trees in a mature Norway spruce stand (Hoeglwald project)

    International Nuclear Information System (INIS)

    Kreutzer, K.; Schierl, R.; Goettlein, A.; Proebstle, P.

    1989-01-01

    Since 1984 the soil of an around 80 years old spruce stand (Picea abies L. Karst.) was irrigated with acidified water (pH 2.7 - 2.8 by H 2 SO 4 resp. pH 5 - 5.5 by H 2 CO 3 ) in 15 to 18 events a 10 - 12 mm per year additionally to natural rain of 500 to 700 mm below canopy with pH mostly between 4.5 - 5.2. The main part of the added acidity was buffered in the mineral top soil by reactions releasing Al (H 2 O) 6 3+ . A small part was consumed in the surface humus layer by exchange of Ca, Mg, Mn and K. Up to now the trees do not show any signs of growth reductions, needle losses or discolourations. It seems that defensive mechanisms in the fine root system are responsible for that as active raise of pH on the rhizoplane of fine roots, possibly due to nitrate uptake. Liming, carried out once in April 1984 with 4 x 10 3 kg ground dolomite per ha, produced a strong increase of the pH only in the upper part of the humus layer, forming a steep pH gradient by depth. That gradient marking the deacidification front is moving downward very slowly with time (around 1 cm/year). Although nitrification was already very active before lime was brought out liming enhanced the nitrate production markedly. At a depth of 20 cm the nitrate concentrations reached 280 mg/l in the soil solution. Liming also enhanced the release of water soluble humic substances. Because of their ability to form stable metal organic complexes with Fe, Cu, Pb and Al, the contents of these metals increased in the soil solutions. (orig.)

  3. Effect of 3 years' free-air exposure to elevated ozone on mature Norway spruce (Picea abies (L.) Karst.) needle epicuticular wax physicochemical characteristics

    International Nuclear Information System (INIS)

    Percy, Kevin E.; Manninen, Sirkku; Haeberle, Karl-Heinz; Heerdt, C.; Werner, H.; Henderson, Gary W.; Matyssek, Rainer

    2009-01-01

    We examined the effect of ozone (O 3 ) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2x ambient O 3 ranged from 64.5 to 74.2 μl O 3 l -1 h AOT40, and 117.1 to 123.2 nl O 3 l -1 4th highest daily maximum 8-h average O 3 concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2x O 3 . Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O 3 treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2x O 3 . Exposure to 2x O 3 increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O 3 on wax biosynthesis. These results demonstrate O 3 -induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees. - Free-air ozone exposure induced changes in needle wax characteristics of mature Picea abies.

  4. Effect of 3 years' free-air exposure to elevated ozone on mature Norway spruce (Picea abies (L.) Karst.) needle epicuticular wax physicochemical characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Percy, Kevin E., E-mail: kpercy@nbnet.nb.c [Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, 1350 Regent Street, Fredericton, NB, E3B 5P7 (Canada); Manninen, Sirkku [Department of Biological and Environmental Sciences, P.O. Box 56, University of Helsinki, 00014 Helsinki (Finland); Department of Biology, P.O. Box 3000, University of Oulu, 90014 Oulu (Finland); Haeberle, Karl-Heinz [Ecophysiology of Plants, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Heerdt, C.; Werner, H. [Ecoclimatology, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Henderson, Gary W. [Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, 1350 Regent Street, Fredericton, NB, E3B 5P7 (Canada); Matyssek, Rainer [Ecophysiology of Plants, Department of Ecology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

    2009-05-15

    We examined the effect of ozone (O{sub 3}) on Norway spruce (Picea abies) needle epicuticular wax over three seasons at the Kranzberg Ozone Fumigation Experiment. Exposure to 2x ambient O{sub 3} ranged from 64.5 to 74.2 mul O{sub 3} l{sup -1} h AOT40, and 117.1 to 123.2 nl O{sub 3} l{sup -1} 4th highest daily maximum 8-h average O{sub 3} concentration. The proportion of current-year needle surface covered by wax tubes, tube aggregates, and plates decreased (P = 0.011) under 2x O{sub 3}. Epistomatal chambers had increased deposits of amorphous wax. Proportion of secondary alcohols varied due to year (P = 0.004) and O{sub 3} treatment (P = 0.029). Secondary alcohols were reduced by 9.1% under 2x O{sub 3}. Exposure to 2x O{sub 3} increased (P = 0.037) proportions of fatty acids by 29%. Opposing trends in secondary alcohols and fatty acids indicate a direct action of O{sub 3} on wax biosynthesis. These results demonstrate O{sub 3}-induced changes in biologically important needle surface characteristics of 50-year-old field-grown trees. - Free-air ozone exposure induced changes in needle wax characteristics of mature Picea abies.

  5. Romanian legal management rules limit wood production in Norway spruce and beech forests

    Directory of Open Access Journals (Sweden)

    Olivier Bouriaud

    2016-09-01

    Full Text Available Background The quantitative impact of forest management on forests’ wood resource was evaluated for Picea and Fagus mixed forests. The effects on the productivity of tendering operations, thinnings and rotation length have seldom been directly quantified on landscape scale. Methods Two sites of similar fertility but subject to contrasted forest management were studied with detailed inventories: one in Germany, the other in Romania, and compared with the respective national forest inventories. In Romania, regulations impose very long rotations, low thinnings and a period of no-cut before harvest. In contrast, tending and thinnings are frequent and intense in Germany. Harvests start much earlier and must avoid clear cutting but maintain a permanent forest cover with natural regeneration. While Germany has an average annual wood increment representative for Central Europe, Romania represents the average for Eastern Europe. Results The lack of tending and thinning in the Romanian site resulted in twice as many trees per hectare as in the German site for the same age. The productivity in Romanian production forests was 20 % lower than in Germany despite a similar fertility. The results were supported by the data from the national forest inventory of each country, which confirmed that the same differential exists at country scale. Furthermore, provided the difference in rotation length, two crops are harvested in Germany when only one is harvested in Romania. The losses of production due to a lower level of management in Romania where estimated to reach 12.8 million m3.y-1 in regular mountain production forests, and to 15 million m3.y-1 if managed protection forest is included. Conclusions The productivity of Picea and Fagus mountain forests in Romania is severely depressed by the lack of tending and thinning, by overly long rotations and the existence of a 25-years no-cut period prior to harvest. The average standing volume in Germany was 50

  6. Distribution of nitrogen-15 tracers applied to the canopy of a mature spruce-hemlock stand, Howland, Maine, USA

    Science.gov (United States)

    David Bryan Dail; David Y. Hollinger; Eric A. Davidson; Ivan Fernandez; Herman C. Sievering; Neal A. Scott; Elizabeth Gaige

    2009-01-01

    In N-limited ecosystems, fertilization by N deposition may enhance plant growth and thus impact C sequestration. In many N deposition-C sequestration experiments, N is added directly to the soil, bypassing canopy processes and potentially favoring N immobilization by the soil. To understand the impact of enhanced N deposition on a low fertility unmanaged forest and...

  7. Leaf gas exchange of understory spruce-fir saplings in relict cloud forests, southern Appalachian Mountains, USA

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, K.; Smith, W.K. [Wake Forest Univ., Winston-Salem, NC (United States). Dept. of Biology

    2008-01-15

    Global climate change is expected to increase regional cloud ceiling levels in many mountainous forested areas of the world. This study investigated environmental influences on the gas exchange physiology of understory red spruce and Fraser fir trees at 2 sites in the Appalachian mountains. The study hypothesized that the humid, cloudy environment would influence the photosynthetic performance of the trees, and that the species would adapt to low, diffuse light. The study also predicted that leaf conductance to carbon dioxide (CO{sub 2}) would be high as a result of low leaf-to-air-vapour pressure deficit (LAVD). The study demonstrated that leaf conductance decreased exponentially as LAVD increased. Predawn leaf water potentials remained stable, while late afternoon values declined. It was concluded that leaf gas exchange was correlated with the response of leaf conductance and LAVD. The cloudy, humid environment strongly influenced tree leaf gas exchange and water relations. It was suggested that further research is needed to investigate cloud impacts on carbon gain and water relations. 72 refs., 1 tab., 8 figs.

  8. Footprint-weighted tile approach for a spruce forest and a nearby patchy clearing using the ACASA model

    Science.gov (United States)

    Gatzsche, Kathrin; Babel, Wolfgang; Falge, Eva; Pyles, Rex David; Tha Paw U, Kyaw; Raabe, Armin; Foken, Thomas

    2018-05-01

    The ACASA (Advanced Canopy-Atmosphere-Soil Algorithm) model, with a higher-order closure for tall vegetation, has already been successfully tested and validated for homogeneous spruce forests. The aim of this paper is to test the model using a footprint-weighted tile approach for a clearing with a heterogeneous structure of the underlying surface. The comparison with flux data shows a good agreement with a footprint-aggregated tile approach of the model. However, the results of a comparison with a tile approach on the basis of the mean land use classification of the clearing is not significantly different. It is assumed that the footprint model is not accurate enough to separate small-scale heterogeneities. All measured fluxes are corrected by forcing the energy balance closure of the test data either by maintaining the measured Bowen ratio or by the attribution of the residual depending on the fractions of sensible and latent heat flux to the buoyancy flux. The comparison with the model, in which the energy balance is closed, shows that the buoyancy correction for Bowen ratios > 1.5 better fits the measured data. For lower Bowen ratios, the correction probably lies between the two methods, but the amount of available data was too small to make a conclusion. With an assumption of similarity between water and carbon dioxide fluxes, no correction of the net ecosystem exchange is necessary for Bowen ratios > 1.5.

  9. Seasonal and diurnal variation in the deposition velocity of ozone over a spruce forest in Denmark

    DEFF Research Database (Denmark)

    Pilegaard, K.; Jensen, N.O.; Hummelshøj, P.

    1995-01-01

    The flux of O-3 was measured by the eddy-correlation method over Norway spruce in periods when the trees had a very low activity, periods with optimum growth, and periods with water stress. The aerodynamic resistance (tau(a)), viscous sub-layer resistance (tau(b)) and surface resistance (tau...... the activity of the trees was low. The surface resistance increased when the trees were subject to water stress. It is concluded that stomatal uptake is an important parameter for the deposition of O-3. However, other processes such as destruction of O-3 at surfaces, reaction with NO emitted from the soil......(c)) to O-3 were calculated from meteorological parameters and the deposition velocity. The canopy stomatal resistance to O-3 was calculated from measurements of the water vapour flux. The deposition velocities showed a diurnal pattern with night-time values of 3.5 mm s(-1) and day-time values of 7 mm s(-1...

  10. Disruption of calcium nutrition at Hubbard Brook Experimental Forest (New Hampshire) alters the health and productivity of red spruce and sugar maple trees and provides lessons pertinent to other sites and regions

    Science.gov (United States)

    Paul G. Schaberg; Gary J. Hawley

    2010-01-01

    Pollution-induced acidification and other anthropogenic factors are leaching calcium (Ca) and mobilizing aluminum (Al) in many forest soils. Because Ca is an essential nutrient and Al is a potential toxin, resulting depletions of Ca and increases in available Al may significantly alter the health and productivity of forest trees. Controlled experiments on red spruce (...

  11. Fluxes of inorganic and organic arsenic species in a Norway spruce forest floor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.-H. [Department of Soil Ecology, University of Bayreuth, D-95440 Bayreuth (Germany)], E-mail: jenhow.huang@uni-bayreuth.de; Matzner, Egbert [Department of Soil Ecology, University of Bayreuth, D-95440 Bayreuth (Germany)

    2007-09-15

    To identify the role of the forest floor in arsenic (As) biogeochemistry, concentrations and fluxes of inorganic and organic As in throughfall, litterfall and forest floor percolates at different layers were investigated. Nearly 40% of total As{sub total} input (5.3 g As ha{sup -1} yr{sup -1}) was retained in Oi layer, whereas As{sub total} fluxes from Oe and Oa layers exceeded the input by far (10.8 and 20 g As ha{sup -1} yr{sup -1}, respectively). Except dimethylarsinic acid (DMA), fluxes of organic As decreased with depth of forest floor so that <10% of total deposition (all <0.3 g As ha{sup -1} yr{sup -1}) reached the mineral soil. All forest floor layers are sinks for most organic As. Conversely, Oe and Oa layers are sources of As{sub total}, arsenite, arsenate and DMA. Significant correlations (r {>=} 0.43) between fluxes of As{sub total}, arsenite, arsenate or DMA and water indicate hydrological conditions and adsorption-desorption as factors influencing their release from the forest floor. The higher net release of arsenite from Oe and Oa and of DMA from Oa layer in the growing than dormant season also suggests microbial influences on the release of arsenite and DMA. - The forest floor layers are generally a source for inorganic arsenic species but a sink for most organic arsenic species under the present deposition rate.

  12. A decade of carbon, water and energy flux measurements of an old spruce forest at the Anchor Station Tharandt

    International Nuclear Information System (INIS)

    Gruenwald, Thomas.; Bernhofer, Christian

    2007-01-01

    At Tharandt/Germany eddy covariance (EC) measurements of carbon dioxide and heat fluxes are performed above an old spruce forest since 1996. The last ten years cover almost all meteorological extremes observed during the last 45 years: the coldest and warmest year with mean air temperature of 6.1 deg C (1996) and 9.6 deg C (2000) as well as the fourth wettest and the driest year with a precipitation of 1098 mm (2002) and 501 mm (2003), respectively. In general, the observed annual carbon net ecosystem exchange (NEE) indicates a high net sink from -395 g C/m 2 /a (2003) to -698 g C/m 2 /a (1999) with a coefficient of variation c v = 16.6%. The yearly evapotranspiration (ET) has a lower interannual variability (cv = 9.5%) between 389 mm (2003) and 537 mm (2000). The influence of flux correction and gap filling on the amount of annual NEE and ET is considerable. Using different methods of gap filling (non-linear regressions, mean diurnal courses) yields annual NEE totals that differ by up to 18%. Consistency analysis regarding energy balance closure, comparisons with independent soil respiration and biomass increment measurements indicate reliability of the fluxes. The average gap of the energy balance is 15% of the available energy based on regression slope with an intercept of 3 to 16 W/m 2 , but around zero for annual flux ratios. Between 47% and 63% of the net ecosystem productivity was fixed above ground according to up-scaled tree ring data and forest inventories, respectively. Chamber measurements of soil respiration yield up to 90% of nighttime EC based total ecosystem respiration. Thus, we conclude that the EC based flux represents an upper limit of the C sink at the site

  13. Changes in species occurrence and phytomass after clearfelling, prescribed burning and slash removal in two Swedish spruce forests

    International Nuclear Information System (INIS)

    Nykvist, N.

    1997-01-01

    In two old Norway spruce stands, the one at Garpenberg in central Sweden, the other at Flakatraesk in northern Sweden, the phytomass of the field- and ground-layer was measured before clearfelling and one and four years later. The phytomass of the field-layer was also measured 10 and 16 years after clearfelling. Of 13-14 plant species originally in the field-layer, 2-3 were not found after clearfelling. In contrast, 15 and 9 new species appeared on the plots on which slash was left, at Garpenberg and at Flakatraesk. Some were short-lived, and 16 years after clearfelling, only 11 and 7, respectively, persisted. Corresponding figures for the plots from which slash was removed were 9 and 8, and for the burnt plots 11 and 9. Clearfelling of the old forests also increased the phytomass of the field-layer. Removal of slash decreased the phytomass of some species, increased it for others. During the first years after burning, phytomass on the burnt plots was less than that on the controls, but three years later it was similar to that on the unburnt plots. The spatial variation in phytomass was great, and no significant difference was found between treatments after clearfelling. The biomass of the most common moss species of Swedish coniferous forests declined strongly after clearfelling. Two new mosses appeared on the clearfelled plots, viz. Polytrichum spp. and Ceratodon purpureus; the latter being found only on burnt plots at Flakatraesk four years after burning 17 refs, 16 figs, 18 tabs. four years after burning 17 refs, 16 figs, 18 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-08-01

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

  15. Ponderosa pine, mixed conifer, and spruce-fir forests [Chapter 2

    Science.gov (United States)

    Michael A. Battaglia; Wayne D. Shepperd

    2007-01-01

    Before European settlement of the interior west of the United States, coniferous forests of this region were influenced by many disturbance regimes, primarily fires, insects, diseases, and herbivory, which maintained a diversity of successional stages and vegetative types across landscapes. Activities after settlement, such as fire suppression, grazing, and logging...

  16. Restoration of Central-European mountain Norway spruce forest 15 years after natural and anthropogenic disturbance

    Czech Academy of Sciences Publication Activity Database

    Nováková, M. H.; Edwards-Jonášová, Magda

    2015-01-01

    Roč. 144, 15 May (2015), s. 120-130 ISSN 0378-1127 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : Picea abies forest * disturbance * bark beetle * salvage logging * natural regeneration * Herb-layer vegetation Subject RIV: GK - Forestry Impact factor: 2.826, year: 2015

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

    Science.gov (United States)

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

    2016-03-01

    Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1-3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1-3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1-3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y-1 for spruce and to about 0.012 y-1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than

  18. Spatial distribution of hydroxylamine and its role in aerobic N2O formation in a Norway spruce forest soil

    Science.gov (United States)

    Liu, S.; Weymann, D.; Gottselig, N.; Wiekenkamp, I.; Vereecken, H.; Brueggemann, N.

    2014-12-01

    Hydroxylamine (HA) as a crucial intermediate in the microbial oxidation of ammonium to nitrite (nitrification) is a potential precursor of abiotic N2O formation in the soil. However, the determination of HA concentration in natural soil samples has not been reported until now. Here, we determined the HA concentrations in organic (Oh) and mineral (Ah) layers of 135 soil samples collected from a spruce forest (Wüstebach, Eifel National Park, Germany) using a novel approach, based on the fast extraction of HA from the soil at a pH of 1.7, the oxidation of HA to N2O with Fe3+, and the analysis of produced N2O using gas chromatography (GC). Meanwhile, N2O emission rates were determined by means of aerobic laboratory incubations of 3-g soil in 22-mL vials. Subsequently, the spatial distribution of soil HA concentrations and N2O emission rates in the Oh and Ah layers of the whole sampling area were analyzed using a geostatistical approach. The correlations among soil HA, N2O emission rate, pH, soil C, N, Fe, Mn and soil water content (SWC) were further explored. The HA concentrations ranged from 0.3-44.6 μg N kg-1 dry soil and 0.02-16.2 μg N kg-1 dry soil in the Oh and the Ah layer, respectively. The spatial distribution of HA was similar in both layers, with substantial spatial variability dependent on soil type, tree density and distance to a stream. For example, HA concentration was greater at locations with a thick litter layer or at locations close to the stream. The average N2O emission rate in the Oh layer was 0.38 μg N kg-1 dry soil h-1, 10-fold larger than in the Ah layer. Interestingly, N2O emission rate exhibited high correlation with soil HA content in the Oh (R2 = 0.65, p < 0.01) and Ah (R2 = 0.45, p < 0.05) layer. The results demonstrated that HA is a crucial component for aerobic N2O formation and emission in spruce forest soils. Moreover, HA concentration was negatively correlated with pH and positively correlated with SWC in the Oh layer, while

  19. Microbial N immobilization is of great importance in acidified mountain spruce forest soils

    Czech Academy of Sciences Publication Activity Database

    Tahovská, K.; Kaňa, Jiří; Bárta, J.; Oulehle, F.; Richter, A.; Šantrůčková, H.

    2013-01-01

    Roč. 59, April (2013), s. 58-71 ISSN 0038-0717 R&D Projects: GA AV ČR(CZ) KJB600960907; GA ČR(CZ) GAP504/12/1218 Institutional support: RVO:60077344 Keywords : N immobilization * microbial biomass * 15 N * N saturation * DOC * nitrate leaching * nitrification * C limitation * fungi/bacteria ratio * forest floor Subject RIV: CE - Biochemistry Impact factor: 4.410, year: 2013

  20. The contribution of hydroxylamine content to spatial variability of N2O formation in soil of a Norway spruce forest

    Science.gov (United States)

    Liu, Shurong; Herbst, Michael; Bol, Roland; Gottselig, Nina; Pütz, Thomas; Weymann, Daniel; Wiekenkamp, Inge; Vereecken, Harry; Brüggemann, Nicolas

    2016-04-01

    Hydroxylamine (NH2OH), a reactive intermediate of several microbial nitrogen turnover processes, is a potential precursor of nitrous oxide (N2O) formation in the soil. However, the contribution of soil NH2OH to soil N2O emission rates in natural ecosystems is unclear. Here, we determined the spatial variability of NH2OH content and potential N2O emission rates of organic (Oh) and mineral (Ah) soil layers of a Norway spruce forest, using a recently developed analytical method for the determination of soil NH2OH content, combined with a geostatistical Kriging approach. Potential soil N2O emission rates were determined by laboratory incubations under oxic conditions, followed by gas chromatographic analysis and complemented by ancillary measurements of soil characteristics. Stepwise multiple regressions demonstrated that the potential N2O emission rates, NH2OH and nitrate (NO3-) content were spatially highly correlated, with hotspots for all three parameters observed in the headwater of a small creek flowing through the sampling area. In contrast, soil ammonium (NH4+) was only weakly correlated with potential N2O emission rates, and was excluded from the multiple regression models. While soil NH2OH content explained the potential soil N2O emission rates best for both layers, also NO3- and Mn content turned out to be significant parameters explaining N2O formation in both soil layers. The Kriging approach was improved markedly by the addition of the co-variable information of soil NH2OH and NO3- content. The results indicate that determination of soil NH2OH content could provide crucial information for the prediction of the spatial variability of soil N2O emissions.

  1. Relation of Chlorophyll Fluorescence Sensitive Reflectance Ratios to Carbon FluxMeasurements ofMontanne Grassland and Norway Spruce Forest Ecosystems in the Temperate Zone

    Czech Academy of Sciences Publication Activity Database

    Ač, Alexander; Malenovský, Z.; Urban, Otmar; Hanuš, Jan; Zitová, Martina; Navrátil, M.; Vráblová, M.; Olejníčková, Julie; Špunda, V.; Marek, Michal V.

    2012-01-01

    Roč. 2012, č. 2012 (2012), s. 1-13 ISSN 1537-744X R&D Projects: GA MŽP(CZ) SP/2D1/70/08; GA MŽP(CZ) SP/2D1/93/07; GA MŠk(CZ) LM2010007; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Chlorophyll fluorescence * carbon flux * forest ecosystems * Norway Spruce * temperate zone Subject RIV: EH - Ecology, Behaviour Impact factor: 1.730, year: 2012

  2. Manganese in the litter fall-forest floor continuum of boreal and temperate pine and spruce forest ecosystems

    DEFF Research Database (Denmark)

    Berg, Björn; Erhagen, Björn; Johansson, Maj-Britt

    2015-01-01

    We have reviewed the literature on the role of manganese (Mn) in the litter fall-to-humus subsystem. Available data gives a focus on North European coniferous forests. Manganese concentrations in pine (Pinus spp.) foliar litter are highly variable both spatially and temporally within the same lit...

  3. Water availability effect on transpiration of the Norway spruce forest stand: a case study

    Czech Academy of Sciences Publication Activity Database

    Bužková, Romana; Pokorný, Radek

    2013-01-01

    Roč. 6, č. 1 (2013), s. 67-74 ISSN 1803-2451 R&D Projects: GA MŠk(CZ) EE2.4.31.0056; GA MŽP(CZ) SP/2D1/70/08; GA MŽP(CZ) SP/2D1/93/07; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : sap flow * tree dominance classes * volumetric soil moisture content * specific sap flux Subject RIV: GK - Forest ry

  4. Spatial Variability of Tree Transpiration Along a Soil Drainage Gradient of Boreal Black Spruce Forest

    Science.gov (United States)

    Angstmann, J. L.; Ewers, B. E.; Kwon, H.; Bond-Lamberty, B.; Amiro, B.; Gower, S. T.

    2008-12-01

    Boreal forests are an integral component in obtaining a predictive understanding of global climate change because they comprise 33% of the world's forests and store large amounts of carbon. Much of this carbon storage is a result of peat formation in cold, poorly-drained soils. Transpiration plays a crucial role in the interaction between carbon and water cycles due to stomatal control of these fluxes. The primary focus of this study is to quantify the spatial variability and drivers of tree transpiration in boreal forest stands across a well- to poorly-drained soil drainage gradient. Species composition of this region of boreal forest changes during succession in well-drained soils from being primarily dominated by Picea mariana with co-dominant Pinus banksiana and Populus tremuloides in younger stands to being dominated solely by Picea marianain older stands. Poorly-drained soils are dominated by Picea mariana and change little with succession. Previous work in well-drained stands showed that 1) tree transpiration changed substantially with stand age due to sapwood-to-leaf area ratio dynamics and 2) minimum leaf water potential (Ψ) was kept constant to prevent excessive cavitation. We hypothesized that 1) minimum Ψ would be constant, 2) transpiration would be proportional to the sapwood-to-leaf area ratio across a soil drainage gradient, and 3) spatial relationships between trees would vary depending on stomatal responses to vapor pressure deficit (D). We tested these hypotheses by measuring Ψ of 33 trees and sap flux from 204 trees utilizing cyclic sampling constructed to study spatial relationships. Measurements were conducted at a 42-year-old stand representing maximum tree diversity during succession. There were no significant differences between growing season averaged Ψ in well- (-0.35 and -1.37 for pre-dawn and mid-day respectively) and poorly- drained soil conditions (-0.38 and -1.41 for pre-dawn and mid-day respectively) for Picea mariana. Water use

  5. Bird species diversity and nesting success in mature, clearcut and shelterwood forest in northern New Hampshire, USA

    Science.gov (United States)

    David I. King; Richard M. DeGraaf

    2000-01-01

    Bird species distribution and predation rates on natural and artificial nests were compared among unmanaged mature, shelterwood, and clearcut northern hardwoods forest to evaluate the effect of these practices on bird populations. Twenty-three of the 48 bird species detected during the study differed significantly in abundance among unmanaged mature forest,...

  6. Contrasting development of declining and living larch-spruce stands after a disturbance event: A case study from the High Tatra Mts.

    Directory of Open Access Journals (Sweden)

    Šebeň Vladimír

    2015-09-01

    Full Text Available The decline of spruce stands caused by bark beetle outbreaks is a serious economic and ecological problem of forestry in Slovakia. In the preceding period, the decline affected mainly secondary spruce forests. Over the last decade, due to large bark-beetle outbreaks this problem has been observed also in natural spruce forests, even at high elevations. We dealt with this issue in a case study of short-term development of larch-spruce stands in the High Tatras (at a site called Štart. We compared the situation in the stand infested by bark beetles several years after the wind-throw in 2004 with the stand unaffected by bark beetles. We separately analysed the development of the mature (parent stands and the regeneration. The results indicated that forest decline caused by bark beetles significantly depended on the stand structure (mainly tree species composition, which affected the period of stand disintegration. Mortality of spruce trees slowed down biomass accumulation (and thus carbon sequestration in the forest ecosystem. In the new stand, pioneer tree species dominated (in the conditions of the High Tatras it is primarily rowan, although their share in the parent stand was negligible. The results showed different trends in the accumulation of below-ground and above-ground biomass in the declined and living stands. In the first years after the stand decline, rowan accumulated significantly more biomass than the main tree species, i.e. spruce. The reverse situation was under the surviving stand, where spruce trees accumulated more biomass than rowan. The different share of spruce and pioneer tree species, mainly rowan, affected the ratio between fixed (in woody parts of trees and rotating (in foliage carbon in the undergrowth. Forest die-back is a big source of carbon emissions from dead individuals, and the compensation of these losses in the form of carbon sequestration by future stands is a matter of several decades.

  7. Structure, development and health status of spruce forests affected by air pollution in the western Krkonoše Mts. in 1979–2014

    Directory of Open Access Journals (Sweden)

    Král Jan

    2015-09-01

    Full Text Available The structure and health status of waterlogged or peaty spruce (Picea abies [L.] Karst. forests in the summit parts of the Krkonoše Mts. in the Czech Republic were studied in 1979–2014. The objective was to evaluate the stand structure, dead wood, trend of the health status and productivity on four permanent research plots (PRP in relation to air pollution (SO2 and NOx concentrations and climatic conditions (temperatures and precipitation amounts. Stand structure was evaluated on the base of the measured parameters of individual trees on PRP. The health status of trees was evaluated according to foliage, and their vitality was assessed according to their radial growth documented by dendrochronological analyses. The radial growth was negatively correlated with SO2 and NOx concentrations. Stand dynamics during the observation period was characterised by increased tree mortality, the presence of dead wood and reduction of stand density from 1983 to 1992, while the most severe impairment of health status and stand stability occurred in 1982–1987. The foliage mass of living trees has been gradually increasing since 1988, but no pronounced improvement of tree vitality was documented after the decrease in SO2 concentration. However, particularly physiologically weakened spruce trees were attacked by the European spruce bark beetle (Ips typographus. The process of forest damage is manifested not only by foliage reduction but also by symptoms of various necroses on the assimilatory organs. In terms of climatic data, the weather in April had the most important effect on radial growth. Diameter increment showed positive statistically significant correlation with temperature in growing season, but the precipitation effect was low.

  8. Windthrow and fallow-forest successions impacts in soil carbon stocks and GHG fluxes spatial variability and dynamics in the Central Russia' reserve spruce ecosystems

    Science.gov (United States)

    Vasenev, Ivan; Ivanov, Alexey; Komarova, Tatyana; Valentini, Riccardo

    2015-04-01

    High spatial and temporal variability is mutual feature for most forest soils that is especially obvious in case of their carbon stocks and GHG fluxes. This phenomenon is generally well-known but not so often becomes the object of special precision investigation in detail and small scales so there are still serious gaps in its principal factors understanding due to their high bioclimatic, regional, landscape, tree species and temporal variability. Southern taiga is one of the most environmentally important world zonal forest ecosystems due to its still comparatively intensive carbon biogeochemical cycle and huge area in the northern Eurasia with strong anthropogenic impacts by Western & Central European and Southern & Eastern Asian regions. Central Forest Biospheric Reserve (Tver region, 360 km to North-West from Moscow) is the principal southern-taiga reserve in the European territory of Russia. Since start of its research activity in 1939 the reserve became the regional center of mature spruce ecosystem structure and dynamics investigation. In 1970-1980-s there have been done complex investigations of windthrow soil patterns and fallow-forest successions. Since middle of 1990-s the ecosystem-level GHG fluxes have been observed by eddy covariance method. Since 2012 the detailed year-round monitoring is running in the southern-taiga zonal station of the regional system RusFluxNet with especial attention on the soil carbon stocks and GHG fluxes spatial variability and dynamics due to windthrow and fallow-forest successions (in frame of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266). Soil carbon dynamics is investigated in decades-hundred-year chronosequences of dominated parcels and different-size windthrow soil cover patterns, including direct investigation during last 33 years with detailed mapping, soil profile morphometrics and bulk density, morphogenetic and statistical analysis of mass data. Morphogenetic analysis of microrelief, soil profile

  9. Effects of artificial defoliation of pines on the structure and physiology of the soil fungal community of a mixed pine-spruce forest

    Science.gov (United States)

    Cullings, Ken; Raleigh, Christopher; New, Michael H.; Henson, Joan

    2005-01-01

    Loss of photosynthetic area can affect soil microbial communities by altering the availability of fixed carbon. We used denaturing gradient gel electrophoresis (DGGE) and Biolog filamentous-fungus plates to determine the effects of artificial defoliation of pines in a mixed pine-spruce forest on the composition of the fungal community in a forest soil. As measured by DGGE, two fungal species were affected significantly by the defoliation of pines (P soil fungus increased. The decrease in the amount of Cenococcum organisms may have occurred because of the formation of extensive hyphal networks by species of this genus, which require more of the carbon fixed by their host, or because this fungus is dependent upon quantitative differences in spruce root exudates. The defoliation of pines did not affect the overall composition of the soil fungal community or fungal-species richness (number of species per core). Biolog filamentous-fungus plate assays indicated a significant increase (P soil fungi and the rate at which these substrates were used, which could indicate an increase in fungal-species richness. Thus, either small changes in the soil fungal community give rise to significant increases in physiological capabilities or PCR bias limits the reliability of the DGGE results. These data indicate that combined genetic and physiological assessments of the soil fungal community are needed to accurately assess the effect of disturbance on indigenous microbial systems.

  10. The spruce budworm and forest: a qualitative comparison of ODE and Boolean models

    Directory of Open Access Journals (Sweden)

    Raina Robeva

    2016-01-01

    Full Text Available Boolean and polynomial models of biological systems have emerged recently as viable companions to differential equations models. It is not immediately clear however whether such models are capable of capturing the multi-stable behaviour of certain biological systems: this behaviour is often sensitive to changes in the values of the model parameters, while Boolean and polynomial models are qualitative in nature. In the past few years, Boolean models of gene regulatory systems have been shown to capture multi-stability at the molecular level, confirming that such models can be used to obtain information about the system’s qualitative dynamics when precise information regarding its parameters may not be available. In this paper, we examine Boolean approximations of a classical ODE model of budworm outbreaks in a forest and show that these models exhibit a qualitative behaviour consistent with that derived from the ODE models. In particular, we demonstrate that these models can capture the bistable nature of insect population outbreaks, thus showing that Boolean models can be successfully utilized beyond the molecular level.

  11. Proceedings of the US/FRG research symposium: effects of atmospheric pollutants on the spruce-fir forests of the Eastern United States and the Federal Republic of Germany

    Science.gov (United States)

    Gerard, tech. coord. Hertel; Gerard Hertel

    1988-01-01

    Includes 66 papers presented at the US/FRG research symposium: effects of atmospheric pollutants on the spruce-fir forests of the Eastern United States and the Federal Republic of Germany, which was held October 19-23, 1987, in Burlington, Vermont.

  12. Carbon uptake by mature Amazon forests has mitigated Amazon nations' carbon emissions.

    Science.gov (United States)

    Phillips, Oliver L; Brienen, Roel J W

    2017-12-01

    Several independent lines of evidence suggest that Amazon forests have provided a significant carbon sink service, and also that the Amazon carbon sink in intact, mature forests may now be threatened as a result of different processes. There has however been no work done to quantify non-land-use-change forest carbon fluxes on a national basis within Amazonia, or to place these national fluxes and their possible changes in the context of the major anthropogenic carbon fluxes in the region. Here we present a first attempt to interpret results from ground-based monitoring of mature forest carbon fluxes in a biogeographically, politically, and temporally differentiated way. Specifically, using results from a large long-term network of forest plots, we estimate the Amazon biomass carbon balance over the last three decades for the different regions and nine nations of Amazonia, and evaluate the magnitude and trajectory of these differentiated balances in relation to major national anthropogenic carbon emissions. The sink of carbon into mature forests has been remarkably geographically ubiquitous across Amazonia, being substantial and persistent in each of the five biogeographic regions within Amazonia. Between 1980 and 2010, it has more than mitigated the fossil fuel emissions of every single national economy, except that of Venezuela. For most nations (Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname) the sink has probably additionally mitigated all anthropogenic carbon emissions due to Amazon deforestation and other land use change. While the sink has weakened in some regions since 2000, our analysis suggests that Amazon nations which are able to conserve large areas of natural and semi-natural landscape still contribute globally-significant carbon sequestration. Mature forests across all of Amazonia have contributed significantly to mitigating climate change for decades. Yet Amazon nations have not directly benefited from providing this global scale

  13. Dynamics and composition of litterfall in an unmanaged Norway spruce (Picea abies) forest after bark-beetle outbreak

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Jiří; Cudlín, Pavel; Fluksová, H.; Kaňa, Jiří; Picek, T.; Šantrůčková, H.; Svoboda, M.; Vaněk, D.

    2015-01-01

    Roč. 20, č. 3 (2015), s. 305-323 ISSN 1239-6095 R&D Projects: GA ČR(CZ) GAP504/12/1218 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : bark beetle * litter * Norway spruce Subject RIV: EH - Ecology, Behaviour Impact factor: 1.476, year: 2015

  14. Carbon pools in a montane old-growth Norway spruce ecosystem in Bohemian Forest: Effects of stand age and elevation

    Czech Academy of Sciences Publication Activity Database

    Seedre, M.; Kopáček, Jiří; Janda, P.; Bače, R.; Svoboda, M.

    2015-01-01

    Roč. 346, June (2015), s. 106-113 ISSN 0378-1127 R&D Projects: GA ČR(CZ) GAP504/12/1218 Institutional support: RVO:60077344 Keywords : carbon dynamics * soil carbon * spruce biomass C * dead root C * unmanaged ecosystem Subject RIV: GK - Forestry Impact factor: 2.826, year: 2015

  15. Carbon sequestration and water flow regulation services in mature Mediterranean Forest

    Science.gov (United States)

    Beguería, S.; Ovando, P.

    2015-12-01

    We develop a forestland use and management model that integrates spatially-explicit biophysical and economic data, to estimate the expected pattern of climate regulation services through carbon dioxide (CO2) sequestration in tree and shrubs biomass, and water flow regulation. We apply this model to examine the potential trade-offs and synergies in the supply of CO2 sequestration and water flow services in mature Mediterranean forest, considering two alternative forest management settings. A forest restoration scenario through investments in facilitating forest regeneration, and a forestry activity abandonment scenario as result of unprofitable forest regeneration investment. The analysis is performed for different discount rates and price settings for carbon and water. The model is applied at the farm level in a group of 567 private silvopastoral farms across Andalusia (Spain), considering the main forest species in this region: Quercus ilex, Q. suber, Pinus pinea, P. halepensis, P. pinaster and Eucalyptus sp., as well as for tree-less shrubland and pastures. The results of this research are provided by forest land unit, vegetation, farm and for the group of municipalities where the farms are located. Our results draw attention to the spatial variability of CO2 and water flow regulation services, and point towards a trade-off between those services. The pattern of economic benefits associated to water and carbon services fluctuates according to the assumptions regarding price levels and discounting rates, as well as in connection to the expected forest management and tree growth models, and to spatially-explicit forest attributes such as existing tree and shrubs inventories, the quality of the sites for growing different tree species, soil structure or the climatic characteristics. The assumptions made regarding the inter-temporal preferences and relative prices have a large effect on the estimated economic value of carbon and water services. These results

  16. Characteristics of organic soil in black spruce forests: Implications for the application of land surface and ecosystem models in cold regions

    Science.gov (United States)

    Yi, S.; Manies, K.; Harden, J.; McGuire, A.D.

    2009-01-01

    Soil organic layers (OL) play an important role in landatmosphere exchanges of water, energy and carbon in cold environments. The proper implementation of OL in land surface and ecosystem models is important for predicting dynamic responses to climate warming. Based on the analysis of OL samples of black spruce (Picea mariana), we recommend that implementation of OL for cold regions modeling: (1) use three general organic horizon types (live, fibrous, and amorphous) to represent vertical soil heterogeneity; (2) implement dynamics of OL over the course of disturbance, as there are significant differences of OL thickness between young and mature stands; and (3) use two broad drainage classes to characterize spatial heterogeneity, as there are significant differences in OL thickness between dry and wet sites. Implementation of these suggestions into models has the potential to substantially improve how OL dynamics influence variability in surface temperature and soil moisture in cold regions. Copyright 2009 by the American Geophys.ical Union.

  17. Excess of Organic Carbon in Mountain Spruce Forest Soils after Bark Beetle Outbreak Altered Microbial N Transformations and Mitigated N-Saturation.

    Directory of Open Access Journals (Sweden)

    Jiří Kaňa

    Full Text Available Mountain forests in National park Bohemian Forest (Czech Republic were affected by bark beetle attack and windthrows in 2004-2008, followed by an extensive tree dieback. We evaluated changes in the biochemistry of the uppermost soil horizons with the emphasis on carbon (C and nitrogen (N cycling in a near-natural spruce (Picea abies mountain forest after the forest dieback, and compared it with an undisturbed control plot of similar age, climate, elevation, deposition, N-saturation level, and land use history. We hypothesised that the high litter input after forest dieback at the disturbed plot and its consequent decomposition might influence the availability of C for microorganisms, and consequently, N transformations in the soil. The concentrations of dissolved organic C (DOC and N (DON in soil water extracts rapidly increased at the disturbed plot for 3 yeas and then continually decreased. Net ammonification exhibited a similar trend as DOC and DON, indicating elevated mineralization. Despite the high ammonium concentrations found after the forest dieback (an increase from 0.5 mmol kg-1 to 2-3 mmol kg-1, net nitrification was stable and low during these 3 years. After the DOC depletion and decrease in microbial biomass 5 years after the forest dieback, net nitrification started to rise, and nitrate concentrations increased from 0.2-1 mmol kg-1 to 2-3 mmol kg-1. Our results emphasize the key role of the availability of organic C in microbial N transformations, which probably promoted microbial heterotrophic activity at the expense of slow-growing nitrifiers.

  18. Detection of Spatio-Temporal Changes of Norway Spruce Forest Stands in Ore Mountains Using Landsat Time Series and Airborne Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Jan Mišurec

    2016-01-01

    Full Text Available The study focuses on spatio-temporal changes in the physiological status of the Norway spruce forests located at the central and western parts of the Ore Mountains (northwestern part of the Czech Republic, which suffered from severe environmental pollution from the 1970s to the 1990s. The situation started improving after the pollution loads decreased significantly at the end of the 1990s. The general trends in forest recovery were studied using the tasseled cap transformation and disturbance index (DI extracted from the 1985–2015 time series of Landsat data. In addition, 16 vegetation indices (VIs extracted from airborne hyperspectral (HS data acquired in 1998 using the Advanced Solid-State Array Spectroradiometer (ASAS and in 2013 using the Airborne Prism Experiment (APEX were used to study changes in forest health. The forest health status analysis of HS image data was performed at two levels of spatial resolution; at a tree level (original 2.0 m spatial resolution, as well as at a forest stand level (generalized to 6.0 m spatial resolution. The temporal changes were studied primarily using the VOG1 vegetation index (VI as it was showing high and stable sensitivity to forest damage for both spatial resolutions considered. In 1998, significant differences between the moderately to heavily damaged (central Ore Mountains and initially damaged (western Ore Mountains stands were detected for all the VIs tested. In 2013, the stands in the central Ore Mountains exhibited VI values much closer to the global mean, indicating an improvement in their health status. This result fully confirms the finding of the Landsat time series analysis. The greatest difference in Disturbance Index (DI values between the central (1998: 0.37 and western Ore Mountains stands (1998: −1.21 could be seen at the end of the 1990s. Nonetheless, levelling of the physiological status of Norway spruce was observed for the central and western parts of the Ore Mountains in

  19. Spatial distribution of lead and lead isotopes in soil B-horizon, forest-floor humus, grass (Avenella flexuosa) and spruce (Picea abies) needles across the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Sucharova, Julie; Suchara, Ivan [Silva Tarouca Research Institute for Landscape and Ornamental Gardening, Kvetnove namesti 391, 252 43 Pruhonice (Czech Republic); Reimann, Clemens, E-mail: Clemens.Reimann@ngu.no [Geological Survey of Norway, P.O. Box 6315 Sluppen, 7491 Trondheim (Norway); Boyd, Rognvald [Geological Survey of Norway, P.O. Box 6315 Sluppen, 7491 Trondheim (Norway); Filzmoser, Peter [Institute for Statistics and Probability Theory, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Wien (Austria); Englmaier, Peter [Faculty of Life Science, University of Vienna, Althanstr. 14, A-1090 Vienna (Austria)

    2011-07-15

    Highlights: > Pb-concentrations and {sup 206}Pb/{sup 207}Pb isotope ratios are provided for four different sample materials for the Czech Republic. > The paper demonstrates the local impact of a number of different contamination sources. > The data provide clear evidence that traffic emissions are no major source of Pb to the Czech environment. > The data demonstrate that the B-horizon provides no valid 'background' for Pb-concentration or the {sup 206}Pb/{sup 207}Pb isotope ratio. > Pb isotope ratios change during soil weathering and at the interface biosphere/pedosphere. - Abstract: Lead concentrations were determined in samples of soil B-horizon (N = 258), forest-floor humus (O-horizon, N = 259), grass (Avenella flexuosa, N = 251) and spruce (Picea abies, N = 253) needles (2nd year) collected at the same locations evenly spread over the territory of the Czech Republic at an average density of 1 site/300 km{sup 2}. Median Pb concentrations differ widely in the four materials: soil B-horizon: 27 mg/kg (3.3-220 mg/kg), humus: 78 mg/kg (19-1863 mg/kg), grass: 0.37 mg/kg (0.08-8 mg/kg) and spruce needles: 0.23 mg/kg (0.07-3 mg/kg). In the Pb distribution maps for humus, grass and spruce a number of well-known Pb-contamination sources are indicated by unusually high concentrations (e.g., the Pb smelter at Pribram, the metallurgical industry in the NE of the Czech Republic and along the Polish border, as well as the metallurgical industry in Upper Silesia and Europe's largest coal-fired power plant at Bogatynia, Poland). The ratio {sup 206}Pb/{sup 207}Pb was determined in all four materials. The median value of the {sup 206}Pb/{sup 207}Pb isotope ratio in the soil B-horizon is 1.184 (variation: 1.145-1.337). In both humus and grass the median value for the {sup 206}Pb/{sup 207}Pb isotope ratio is 1.162 (variation: 1.130-1.182), in spruce needles the median ratio is 1.159 (variation: 1.116-1.186). In humus, grass and spruce needles the known contamination

  20. Effects of artificial defoliation of pines on the structure and physiology of the soil fungal community of a mixed pine-spruce forest

    Science.gov (United States)

    Cullings, Ken; Raleigh, Christopher; New, Michael H.; Henson, Joan

    2005-01-01

    Loss of photosynthetic area can affect soil microbial communities by altering the availability of fixed carbon. We used denaturing gradient gel electrophoresis (DGGE) and Biolog filamentous-fungus plates to determine the effects of artificial defoliation of pines in a mixed pine-spruce forest on the composition of the fungal community in a forest soil. As measured by DGGE, two fungal species were affected significantly by the defoliation of pines (P the frequency of members of the ectomycorrhizal fungus genus Cenococcum decreased significantly, while the frequency of organisms of an unidentified soil fungus increased. The decrease in the amount of Cenococcum organisms may have occurred because of the formation of extensive hyphal networks by species of this genus, which require more of the carbon fixed by their host, or because this fungus is dependent upon quantitative differences in spruce root exudates. The defoliation of pines did not affect the overall composition of the soil fungal community or fungal-species richness (number of species per core). Biolog filamentous-fungus plate assays indicated a significant increase (P the number of carbon substrates utilized by the soil fungi and the rate at which these substrates were used, which could indicate an increase in fungal-species richness. Thus, either small changes in the soil fungal community give rise to significant increases in physiological capabilities or PCR bias limits the reliability of the DGGE results. These data indicate that combined genetic and physiological assessments of the soil fungal community are needed to accurately assess the effect of disturbance on indigenous microbial systems.

  1. Release of Suppressed Red Spruce Using Canopy Gap Creation--Ecological Restoration in the Central Appalachians

    Science.gov (United States)

    J.S. Rentch; W.M. Ford; Thomas Schuler; Jeff Palmer; C.A. Diggins

    2016-01-01

    Red spruce (Picea rubens) and red spruce-northern hardwood mixed stands once covered as much as 300,000 ha in the Central Appalachians, but now comprise no more than 21,000 ha. Recently, interest in restoration of this forest type has increased because red spruce forests provide habitat for a number of rare animal species. Our study reports the...

  2. Nesting ecology of Townsend's warblers in relation to habitat characteristics in a mature boreal forest

    Science.gov (United States)

    Matsuoka, S.M.; Handel, Colleen M.; Roby, D.D.

    1997-01-01

    We investigated the nesting ecology of Townsend's Warblers (Dendroica townsendi) from 1993-1995 in an unfragmented boreal forest along the lower slopes of the Chugach Mountains in southcentral Alaska. We examined habitat characteristics of nest sites in relation to factors influencing reproductive success. Almost all territory-holding males (98%, n = 40) were successful in acquiring mates. Nest success was 54% (n = 24 nests), with nest survivorship greater during incubation (87%) than during the nestling period (62%). Most nesting failure (80%) was attributable to predation, which occurred primarily during the nestling period. Fifty-five percent of nests containing nestling were infested with the larvae of bird blow-flies (Protocalliphora braueri and P. spenceri), obligatory blood-feeding parasites. The combined effects of Protocalliphora infestation and inclement weather apparently resulted in nestling mortality in 4 of the 24 nests. Nests that escaped predation were placed in white spruce with larger diameter than those lost to predation: nests that escaped blow-fly parasitism were located higher in nest trees and in areas with lower densities of woody shrubs than those that were infested. The availability of potential nest sites with these key features may be important in determining reproductive success in Townsend's Warblers.

  3. Diversity patterns of ground beetles and understory vegetation in mature, secondary, and plantation forest regions of temperate northern China.

    Science.gov (United States)

    Zou, Yi; Sang, Weiguo; Wang, Shunzhong; Warren-Thomas, Eleanor; Liu, Yunhui; Yu, Zhenrong; Wang, Changliu; Axmacher, Jan Christoph

    2015-02-01

    Plantation and secondary forests form increasingly important components of the global forest cover, but our current knowledge about their potential contribution to biodiversity conservation is limited. We surveyed understory plant and carabid species assemblages at three distinct regions in temperate northeastern China, dominated by mature forest (Changbaishan Nature Reserve, sampled in 2011 and 2012), secondary forest (Dongling Mountain, sampled in 2011 and 2012), and forest plantation habitats (Bashang Plateau, sampled in 2006 and 2007), respectively. The α-diversity of both taxonomic groups was highest in plantation forests of the Bashang Plateau. Beetle α-diversity was lowest, but plant and beetle species turnover peaked in the secondary forests of Dongling Mountain, while habitats in the Changbaishan Nature Reserve showed the lowest turnover rates for both taxa. Changbaishan Nature Reserve harbored the highest proportion of forest specialists. Our results suggest that in temperate regions of northern China, the protected larch plantation forest established over extensive areas might play a considerable role in maintaining a high biodiversity in relation to understory herbaceous plant species and carabid assemblages, which can be seen as indicators of forest disturbance. The high proportion of phytophagous carabids and the rarity of forest specialists reflect the relatively homogenous, immature status of the forest ecosystems on the Bashang Plateau. China's last remaining large old-growth forests like the ones on Changbaishan represent stable, mature ecosystems which require particular conservation attention.

  4. Cytophotometric differentiation of high elevation spruces: physiological and ecological implications

    International Nuclear Information System (INIS)

    Berlyn, G.P.; Royte, J.L.; Anoruo, A.O.

    1990-01-01

    Red and black spruce and their hybrids can be determined by morphological indices; however, the criteria are somewhat subjective and increasingly difficult to use at higher elevations. Although the chromosome number is identical (2n = 24), red spruce has twice as much nuclear DNA (48 pg) than black spruce (24 pg) and thus the species and their hybrids can also be separated by cytophotometry. This is relevant to spruce decline studies because black spruce is much more resistant to high elevation environmental stresses, both natural and anthropogenic. It also has implications for the effect of climatic changes on the composition of high elevation spruce-fir forests because red spruce can outcompete black spruce under more mesic conditions. Four elevation transects sampling spruce on the east and west sides of Mount Washington (New Hampshire) and Camels Hump (Vermont) and a single transect on the southwest side of Whiteface Mountain (New York) were made to investigate the degree of hybridization and introgression between these two species. A positive correlation was found between increased elevation and increased black spruce genes on Mount Washington and Camels Hump. Pure black spruce was found on Mount Washington from 1356 m to 1582 m. No pure black or red spruce was found on Camels Hump although the proportion of red spruce alleles was significantly greater on Camels Hump. All trees sampled at all elevations on Whiteface Mountain were pure red spruce. Thus the proportion of black spruce alleles in high elevation spruce populations decreases from east to west. This closely parallels the increase in spruce decline which increases from east to west. (author)

  5. Effects of Aluminium in Forest. Results of a pilot experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, J; Wit, H de; Nygaard, P H

    1996-01-01

    This conference paper deals with an Norwegian pilot project which started in 1995 and finishing early 1999, investigates the solubility and phyto-toxicity of aluminium (Al) in mature forest ecosystems. The project consists of three major parts, including field manipulation study of Norwegian spruce stands, laboratory experiments and modelling Al chemistry in the root zone. 15 refs.

  6. Long-term effects of clear-cutting and selective cutting on soil methane fluxes in a temperate spruce forest in southern Germany

    International Nuclear Information System (INIS)

    Wu Xing; Brueggemann, Nicolas; Gasche, Rainer; Papen, Hans; Willibald, Georg; Butterbach-Bahl, Klaus

    2011-01-01

    Based on multi-year measurements of CH 4 exchange in sub-daily resolution we show that clear-cutting of a forest in Southern Germany increased soil temperature and moisture and decreased CH 4 uptake. CH 4 uptake in the first year after clear-cutting (-4.5 ± 0.2 μg C m -2 h -1 ) was three times lower than during the pre-harvest period (-14.2 ± 1.3 μg C m -2 h -1 ). In contrast, selective cutting did not significantly reduce CH 4 uptake. Annual mean uptake rates were -1.18 kg C ha -1 yr -1 (spruce control), -1.16 kg C ha -1 yr -1 (selective cut site) and -0.44 kg C ha -1 yr -1 (clear-cut site), respectively. Substantial seasonal and inter-annual variations in CH 4 fluxes were observed as a result of significant variability of weather conditions, demonstrating the need for long-term measurements. Our findings imply that a stepwise selective cutting instead of clear-cutting may contribute to mitigating global warming by maintaining a high CH 4 uptake capacity of the soil. - Highlights: → Long-term, sub-daily measurements of CH 4 exchange at differently managed forest sites. → Inter-annual variability in CH 4 uptake is affected by annual precipitation. → Clear-cutting reduces the CH 4 sink strength of forest soils, whereas thinning has no significant effect. → Sink strength changes due to clear cutting are long-term and were still present approx. nine years following forest harvest. - Forest management affects the soil CH 4 sink strength, with clear-cutting reducing uptake rates for at least eight years.

  7. A 3-year continuous record of nitrogen trace gas fluxes from untreated and limed soil of a N-saturated spruce and beech forest ecosystem in Germany: 1. N2O emissions

    Science.gov (United States)

    Papen, Hans; Butterbach-Bahl, Klaus

    1999-08-01

    For 3 years we followed the complete annual cycles of N2O emission rates with 2-hour resolution in spruce and beech plantations of the Höglwald Forest, Bavaria, Germany, in order to gain detailed information about seasonal and interannual variations of N2O emissions. In addition, microbiological process studies were performed for identification of differences in N turnover rates in the soil of a spruce and a beech site and for estimation of the contribution of nitrification and denitrification to the actual N2O emission. Both pronounced seasonal and extreme interannual variations of N2O emissions were identified. During long-term frost periods, while the soil was frozen, and during soil thawing, extremely high N2O emissions occurred, contributing up to 73% to the total annual N2O loss. The enormous N2O releases during the long-term frost period were due to high microbial N turnover rates (tight coupling of ammonification, nitrification, denitrification) in small unfrozen water films of the frozen soil at high concentrations of easily degradable substrates derived from the enormous pool of dead microbial biomass produced during the long-term frost period. Liming of a spruce site resulted in a significant increase in ammonification, nitrification, and N2O emissions as compared with an untreated spruce control site. The beech control site exhibited 4-5 times higher N2O emissions than the spruce control site, indicating that forest type itself is an important modulator of N2O release from soil. At all sites, nitrification contributed ˜70% to the N2O flux, whereas denitrification contributed markedly less (˜30%). There was a significant positive correlation between amount of in situ N input by wet deposition and magnitude of in situ N2O emissions. At the beech site, 10% of the actual N input was released from the soil in form of N2O, whereas at the spruce site the fraction was 0.5%. N2O emission rates were positively correlated with net nitrification rates. The

  8. Predictive Modeling of Black Spruce (Picea mariana (Mill. B.S.P. Wood Density Using Stand Structure Variables Derived from Airborne LiDAR Data in Boreal Forests of Ontario

    Directory of Open Access Journals (Sweden)

    Bharat Pokharel

    2016-12-01

    Full Text Available Our objective was to model the average wood density in black spruce trees in representative stands across a boreal forest landscape based on relationships with predictor variables extracted from airborne light detection and ranging (LiDAR point cloud data. Increment core samples were collected from dominant or co-dominant black spruce trees in a network of 400 m2 plots distributed among forest stands representing the full range of species composition and stand development across a 1,231,707 ha forest management unit in northeastern Ontario, Canada. Wood quality data were generated from optical microscopy, image analysis, X-ray densitometry and diffractometry as employed in SilviScan™. Each increment core was associated with a set of field measurements at the plot level as well as a suite of LiDAR-derived variables calculated on a 20 × 20 m raster from a wall-to-wall coverage at a resolution of ~1 point m−2. We used a multiple linear regression approach to identify important predictor variables and describe relationships between stand structure and wood density for average black spruce trees in the stands we observed. A hierarchical classification model was then fitted using random forests to make spatial predictions of mean wood density for average trees in black spruce stands. The model explained 39 percent of the variance in the response variable, with an estimated root mean square error of 38.8 (kg·m−3. Among the predictor variables, P20 (second decile LiDAR height in m and quadratic mean diameter were most important. Other predictors describing canopy depth and cover were of secondary importance and differed according to the modeling approach. LiDAR-derived variables appear to capture differences in stand structure that reflect different constraints on growth rates, determining the proportion of thin-walled earlywood cells in black spruce stems, and ultimately influencing the pattern of variation in important wood quality attributes

  9. Certified reference materials - beech leaves and spruce needles - for the quality control in monitoring damage in forests by acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maier, E A; Griepink, B [Commission of the European Communities, Brussels (Belgium). Community Bureau of Reference; Muntau, H [Commission of the European Communities, Ispra (Italy). Joint Research Centre

    1989-12-01

    The chemical determination of various elements in leaves or needles allows to establish the damage caused by acid deposition. To control the quality of such determinations the Community Bureau of Reference (BCR) produced two Certified Reference Materials: Beech leaves (CRM No. 100) and Spruce needles (CRM No. 101). After a careful preparation procedure, a homogeneity study and a long term stability study, the materials were certified for: Cl, N, P and S in CRM No. 100, Al, Ca, Cl, Mg, Mn, N, P, S and Zn in CRM No. 101. Indicative values on the content of 19 majors and trace elements are also reported. (orig.).

  10. Cost efficiency of measures to increase the amount of coarse woody debris in managed Norway spruce forest

    OpenAIRE

    Ranius, Thomas; Ekvall, Hans; Jonsson, Mattias; Bostedt, Göran

    2005-01-01

    Changing silvicultural methods in managed forestland to improve habitat quality for forest organisms has become one of the main means to preserve forest biodiversity in Fennoscandia. In boreal forests, coarse woody debris (CWD) is an important substrate for red-listed species. In this study, we analyse cost efficiency of five management measures taken in Swedish forestry, which aim at increasing CWD in managed forests: retention of living trees at harvest, artificial creation of high stumps, ...

  11. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Science.gov (United States)

    Huang, Jian-Guo; Stadt, Kenneth J; Dawson, Andria; Comeau, Philip G

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2)>0.67) to represent this complex variation in growth as a function of site, size and competition.

  12. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Directory of Open Access Journals (Sweden)

    Jian-Guo Huang

    Full Text Available We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA, the sum of stem diameter at breast height (SDBH, and density (N for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR, were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2>0.67 to represent this complex variation in growth as a function of site, size and competition.

  13. SPRUCE experiment data infrastructure

    Science.gov (United States)

    Krassovski, M.; Hanson, P. J.; Boden, T.; Riggs, J.; Nettles, W. R.; Hook, L. A.

    2013-12-01

    The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL), USA has provided scientific data management support for the US Department of Energy and international climate change science since 1982. Among the many data activities CDIAC performs are design and implementation of the data systems. One current example is the data system and network for SPRUCE experiment. The SPRUCE experiment (http://mnspruce.ornl.gov) is the primary component of the Terrestrial Ecosystem Science Scientific Focus Area of ORNL's Climate Change Program, focused on terrestrial ecosystems and the mechanisms that underlie their responses to climatic change. The experimental work is to be conducted in a bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). The site is located at the southern margin of the boreal peatland forest. Experimental work in the 8.1-ha S1 bog will be a climate change manipulation focusing on the combined responses to multiple levels of warming at ambient or elevated CO2 (eCO2) levels. The experiment provides a platform for testing mechanisms controlling the vulnerability of organisms, biogeochemical processes and ecosystems to climatic change (e.g., thresholds for organism decline or mortality, limitations to regeneration, biogeochemical limitations to productivity, the cycling and release of CO2 and CH4 to the atmosphere). The manipulation will evaluate the response of the existing biological communities to a range of warming levels from ambient to +9°C, provided via large, modified open-top chambers. The ambient and +9°C warming treatments will also be conducted at eCO2 (in the range of 800 to 900 ppm). Both direct and indirect effects of these experimental perturbations will be analyzed to develop and refine models needed for full Earth system analyses. SPRUCE provides wide range continuous and discrete measurements. To successfully manage SPRUCE data flow

  14. Land use history and population dynamics of free-standing figs in a maturing forest.

    Directory of Open Access Journals (Sweden)

    Larissa Albrecht

    Full Text Available Figs (Ficus sp. are often considered as keystone resources which strongly influence tropical forest ecosystems. We used long-term tree-census data to track the population dynamics of two abundant free-standing fig species, Ficus insipida and F. yoponensis, on Barro Colorado Island (BCI, a 15.6-km2 island in Lake Gatún, Panama. Vegetation cover on BCI consists of a mosaic of old growth (>400 years and maturing (about 90-150 year old secondary rainforest. Locations and conditions of fig trees have been mapped and monitored on BCI for more than 35 years (1973-2011, with a focus on the Lutz Catchment area (25 ha. The original distribution of the fig trees shortly after the construction of the Panama Canal was derived from an aerial photograph from 1927 and was compared with previous land use and forest status. The distribution of both fig species (~850 trees is restricted to secondary forest. Of the original 119 trees observed in Lutz Catchment in 1973, >70% of F. insipida and >90% of F. yoponensis had died by 2011. Observations in other areas on BCI support the trend of declining free-standing figs. We interpret the decline of these figs on BCI as a natural process within a maturing tropical lowland forest. Senescence of the fig trees appears to have been accelerated by severe droughts such as the strong El Niño event in the year 1982/83. Because figs form such an important food resource for frugivores, this shift in resource availability is likely to have cascading effects on frugivore populations.

  15. Quercus rubra-associated ectomycorrhizal fungal communities of disturbed urban sites and mature forests.

    Science.gov (United States)

    Karpati, Amy S; Handel, Steven N; Dighton, John; Horton, Thomas R

    2011-08-01

    The presence and quality of the belowground mycorrhizal fungal community could greatly influence plant community structure and host species response. This study tests whether mycorrhizal fungal communities in areas highly impacted by anthropogenic disturbance and urbanization are less species rich or exhibit lower host root colonization rates when compared to those of less disturbed systems. Using a soil bioassay, we sampled the ectomycorrhizal fungal (EMF) communities associating with Quercus rubra (northern red oak) seedlings in soil collected from seven sites: two mature forest reference sites and five urban sites of varying levels of disturbance. Morphological and polymerase chain reaction-restriction fragment length polymorphism analyses of fungi colonizing root tips revealed that colonization rates and fungal species richness were significantly lower on root systems of seedlings grown in disturbed site soils. Analysis of similarity showed that EMF community composition was not significantly different among several urban site soils but did differ significantly between mature forest sites and all but one urban site. We identified a suite of fungal species that occurred across several urban sites. Lack of a diverse community of belowground mutualists could be a constraint on urban plant community development, especially of late-successional woodlands. Analysis of urban EMF communities can add to our understanding of urban plant community structure and should be addressed during ecological assessment before pragmatic decisions to restore habitats are framed.

  16. Defence reactions of mature Norway spruce (Picea abies before and after inoculation of the blue-stain fungus Endoconidiophora polonica in a drought stress experiment

    Directory of Open Access Journals (Sweden)

    Netherer Sigrid

    2016-12-01

    Full Text Available We performed an inoculation experiment using the blue-stain fungus Endoconidiophora polonica at the Rosalia Roof study site, which was set up to study drought effects on Norway spruce susceptibility to attacks by the European spruce bark beetle Ips typographus. Tree resistance parameters such as resin flow rate and extent of hypersensitive wound reaction in the phloem were investigated prior to and after fungal infection. Sample trees with different drought treatments (trees fully covered or semi-covered by roofs, control trees were inoculated with E. polonica in July 2014. In order to check for areas of phloem necrosis, the outer bark around the inoculation holes was scratched off 6 weeks later. We recorded the amount of resin exudation within 12 hours overnight in August and September 2013 and 2014. Although wound reaction zones did not differ in size between tree collectives of the various treatments, fully covered trees tended to exhibit larger necrotic areas compared to control trees. The least water supplied trees showed lowest resin flow rates prior to fungal inoculation, but were the only group to show significantly enhanced resin flow five weeks after the evaluation of defence reactions. Our results agree with earlier findings that wounding and few fungal inoculations can increase tree resistance in the medium term given not too severe water stress. Further investigations will clarify how water stress affects the availability of non-structural carbohydrates for secondary metabolism, when depletion of resources eventually occurs, and at which point trees are most susceptible to bark beetle attack.

  17. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    Science.gov (United States)

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The impact of Norway spruce planting on herb vegetation in the mountain beech forests on two bedrock types

    Czech Academy of Sciences Publication Activity Database

    Máliš, František; Ujházy, K.; Vodálová, A.; Barka, I.; Čaboun, V.; Sitková, Z.

    2012-01-01

    Roč. 131, č. 5 (2012), s. 1551-1569 ISSN 1612-4669 Institutional support: RVO:67985939 Keywords : boreal forests * Bavarian Alps * temperate forests * soil * biodiversity * nitrogen mineralizaton Subject RIV: EF - Botanics Impact factor: 1.959, year: 2012

  19. Experimental soil warming effects on C, N, and major element cycling in a low elevation spruce-fir forest soil

    Science.gov (United States)

    Lindsey E. Rustad; Ivan J. Fernandez; Stephanie Arnold

    1996-01-01

    The effect of global warming on north temperate and boreal forest soils has been the subject of much recent debate. These soils serve as major reservoirs for C, N, and other nutrients necessary for forest growth and productivity. Given the uncertainties in estimates of organic matter turnover rates and storage, it is unclear whether these soils will serve as short or...

  20. Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce (Picea rubens) trees during the cold season

    Science.gov (United States)

    Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher. Eagar

    2011-01-01

    Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology of red spruce during the cold season, we measured concentrations of foliar...

  1. The diversity of microhabitats and their impact on the regeneration of spruce and rowan in the mountain forests of the Low Tatras

    International Nuclear Information System (INIS)

    Gloncak, P.

    2010-01-01

    In this paper the authors describe the questions: what is proportion of different types of microhabitats in natural spruce?; which types of microhabitats prefers spruce (Picea abies) and rowan (Sorbus aucuparia) in the early stages of their development?; what role do ground vegetation and dead wood play?

  2. The diversity of microhabitats and their impact on the regeneration of spruce and rowan in the mountain forests of the Low Tatras

    International Nuclear Information System (INIS)

    Gloncak, P.

    2010-01-01

    In this presentation the authors describe the questions: what is proportion of different types of microhabitats in natural spruce?; which types of microhabitats prefers spruce (Picea abies) and rowan (Sorbus aucuparia) in the early stages of their development?; what role do ground vegetation and dead wood play?

  3. Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data

    Science.gov (United States)

    Barrett, K.; Kasischke, E. S.; McGuire, A. D.; Turetsky, M. R.; Kane, E. S.

    2010-01-01

    Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface

  4. Phosphatase activity in relation to key litter and soil properties in mature subtropical forests in China.

    Science.gov (United States)

    Hou, Enqing; Chen, Chengrong; Wen, Dazhi; Liu, Xian

    2015-05-15

    Phosphatase-mediated phosphorus (P) mineralization is one of the critical processes in biogeochemical cycling of P and determines soil P availability in forest ecosystems; however, the regulation of soil phosphatase activity remains elusive. This study investigated the potential extracellular activities of acid phosphomonoesterase (AcPME) and phosphodiesterase (PDE) and how they were related to key edaphic properties in the L horizon (undecomposed litter) and F/H horizon (fermented and humified litter) and the underlying mineral soil at the 0-15cm depth in eight mature subtropical forests in China. AcPME activity decreased significantly in the order of F/H horizon>L horizon>mineral soil horizon, while the order for PDE activity was L horizon=F/H horizon>mineral soil horizon. AcPME (X axis) and PDE (Y axis) activities were positively correlated in all horizons with significantly higher slope in the L and F/H horizons than in the mineral soil horizon. Both AcPME and PDE activities were positively related to microbial biomass C, moisture content and water-holding capacity in the L horizon, and were positively related to soil C:P, N:P and C:N ratios and fine root (diameter≤2mm) biomass in the mineral soil horizon. Both enzyme activities were also interactively affected by forest and horizon, partly due to the interactive effect of forest and horizon on microbial biomass. Our results suggest that modulator(s) of the potential extracellular activity of phosphatases vary with horizon, depending on the relative C, P and water availability of the horizon. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Searching for indicator species of old-growth spruce forests: studies in the genus Jahnoporus (Polyporales, Basidiomycota)

    Czech Academy of Sciences Publication Activity Database

    Spirin, V.; Vlasák, Josef; Milakovsky, B.; Miettinen, O.

    2015-01-01

    Roč. 36, č. 4 (2015), s. 409-417 ISSN 0181-1584 Institutional support: RVO:60077344 Keywords : Forest conservation * polypores * wood-rotting fungi Subject RIV: EF - Botanics Impact factor: 1.509, year: 2015

  6. Analytical approaches to the determination of simple biophenols in forest trees such as Acer (maple), Betula (birch), Coniferus, Eucalyptus, Juniperus (cedar), Picea (spruce) and Quercus (oak).

    Science.gov (United States)

    Bedgood, Danny R; Bishop, Andrea G; Prenzler, Paul D; Robards, Kevin

    2005-06-01

    Analytical methods are reviewed for the determination of simple biophenols in forest trees such as Acer (maple), Betula (birch), Coniferus, Eucalyptus, Juniperus (cedar), Picea (spruce) and Quercus (oak). Data are limited but nevertheless clearly establish the critical importance of sample preparation and pre-treatment in the analysis. For example, drying methods invariably reduce the recovery of biophenols and this is illustrated by data for birch leaves where flavonoid glycosides were determined as 12.3 +/- 0.44 mg g(-1) in fresh leaves but 9.7 +/- 0.35 mg g(-1) in air-dried samples (data expressed as dry weight). Diverse sample handling procedures have been employed for recovery of biophenols. The range of biophenols and diversity of sample types precludes general procedural recommendations. Caution is necessary in selecting appropriate procedures as the high reactivity of these compounds complicates their analysis. Moreover, our experience suggests that their reactivity is very dependent on the matrix. The actual measurement is less contentious and high performance separation methods particularly liquid chromatography dominate analyses whilst coupled techniques involving electrospray ionization are becoming routine particularly for qualitative applications. Quantitative data are still the exception and are summarized for representative species that dominate the forest canopy of various habitats. Reported concentrations for simple phenols range from trace level (<0.1 microg g(-1)) to in excess of 500 microg g(-1) depending on a range of factors. Plant tissue is one of these variables but various biotic and abiotic processes such as stress are also important considerations.

  7. Importance of Arboreal Cyanolichen Abundance to Nitrogen Cycling in Sub-Boreal Spruce and Fir Forests of Central British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    Ania Kobylinski

    2015-07-01

    Full Text Available The importance of N2-fixing arboreal cyanolichens to the nitrogen (N-balance of sub-boreal interior hybrid spruce (Picea glauca × engelmannii and subalpine fir (Abies lasiocarpa forests was examined at field sites in central BC, Canada. Host trees were accessed by a single-rope climbing technique and foliage as well as arboreal macrolichen functional groups were sampled by branch height in eight random sample trees from each of two high (High Cyano and two low (Low Cyano cyanolichen abundance sites for a total of 32 sample trees. Natural abundances of stable isotopes of N (15N, 14N and carbon (13C, 12C were determined for aggregate host tree and epiphytic lichen samples, as well as representative samples of upper organic and soil horizons (Ae and Bf from beneath host trees. As expected, N2-fixing cyanolichens had 2–6-fold greater N-contents than chlorolichens and a δ15N close to atmospheric N2, while foliage and chlorolichens were more depleted in 15N. By contrast, soils at all trees and sites were 15N-enriched (positive δ15N, with declining (not significant δ15N with increased tree-level cyanolichen abundance. Lichen functional groups and tree foliage fell into three distinct groups with respect to δ13C; the tripartite cyanolichen Lobaria pulmonaria (lightest, host-tree needles (intermediate, and bipartite cyanolichens, hair (Alectoria and Bryoria spp. and chlorolichens (heaviest. Branch height of host trees was an effective predictor of needle δ13C. Our results showed a modest positive correlation between host tree foliage N and cyanolichen abundance, supporting our initial hypothesis that higher cyanolichen abundances would elevate host tree foliar N. Further study is required to determine if high cyanolichen abundance enhances host tree and/or stand-level productivity in sub-boreal forests of central BC, Canada.

  8. Seasonal differences and within-canopy variations of antioxidants in mature spruce (Picea abies) trees under elevated ozone in a free-air exposure system

    International Nuclear Information System (INIS)

    Hofer, Nora; Alexou, Maria; Heerdt, Christian; Loew, Markus; Werner, Herbert; Matyssek, Rainer; Rennenberg, Heinz; Haberer, Kristine

    2008-01-01

    The effect of free-air ozone fumigation and crown position on antioxidants were determined in old-growth spruce (Picea abies) trees in the seasonal course of two consecutive years (2003 and 2004). Levels of total ascorbate and its redox state in the apoplastic washing fluid (AWF) were increased under double ambient ozone concentrations (2 x O 3 ), whilst ascorbate concentrations in needle extracts were unchanged. Concentrations of apoplastic and symplastic ascorbate were significantly higher in 2003 compared to 2004 indicating a combined effect of the drought conditions in 2003 with enhanced ozone exposure. Elevated ozone had only weak effects on total glutathione levels in needle extracts, phloem exudates and xylem saps. Total and oxidised glutathione concentrations were higher in 2004 compared to 2003 and seemed to be more affected by enhanced ozone influx in the more humid year 2004 compared to the combined effect of elevated ozone and drought in 2003 as observed for ascorbate. - Antioxidant defence in sun and shade needles of Picea abies under free-air ozone fumigation in the seasonal course of two consecutive years

  9. Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska

    International Nuclear Information System (INIS)

    Genet, H; Euskirchen, E S; McGuire, A D; Barrett, K; Breen, A; Bennett, A; Rupp, T S; Johnstone, J F; Kasischke, E S; Melvin, A M; Mack, M C; Schuur, A E G; Turetsky, M R; Yuan, F

    2013-01-01

    There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through consumption by fire increases the vulnerability of permafrost to thaw, and the carbon stored in permafrost to decomposition. In this study we ask how warming and fire regime may influence spatial and temporal changes in active layer and carbon dynamics across a boreal forest landscape in interior Alaska. To address this question, we (1) developed and tested a predictive model of the effect of fire severity on soil organic horizons that depends on landscape-level conditions and (2) used this model to evaluate the long-term consequences of warming and changes in fire regime on active layer and soil carbon dynamics of black spruce forests across interior Alaska. The predictive model of fire severity, designed from the analysis of field observations, reproduces the effect of local topography (landform category, the slope angle and aspect and flow accumulation), weather conditions (drought index, soil moisture) and fire characteristics (day of year and size of the fire) on the reduction of the organic layer caused by fire. The integration of the fire severity model into an ecosystem process-based model allowed us to document the relative importance and interactions among local topography, fire regime and climate warming on active layer and soil carbon dynamics. Lowlands were more resistant to severe fires and climate warming, showing smaller increases in active layer thickness and soil carbon loss compared to drier flat uplands and slopes. In simulations that included the effects of both warming and fire at the regional scale, fire was primarily responsible for a reduction in organic layer thickness of 0.06 m on average by 2100 that led to an increase in active layer thickness

  10. Abrupt fire regime change may cause landscape-wide loss of mature obligate seeder forests.

    Science.gov (United States)

    Bowman, David M J S; Murphy, Brett P; Neyland, Dominic L J; Williamson, Grant J; Prior, Lynda D

    2014-03-01

    Obligate seeder trees requiring high-severity fires to regenerate may be vulnerable to population collapse if fire frequency increases abruptly. We tested this proposition using a long-lived obligate seeding forest tree, alpine ash (Eucalyptus delegatensis), in the Australian Alps. Since 2002, 85% of the Alps bioregion has been burnt by several very large fires, tracking the regional trend of more frequent extreme fire weather. High-severity fires removed 25% of aboveground tree biomass, and switched fuel arrays from low loads of herbaceous and litter fuels to high loads of flammable shrubs and juvenile trees, priming regenerating stands for subsequent fires. Single high-severity fires caused adult mortality and triggered mass regeneration, but a second fire in quick succession killed 97% of the regenerating alpine ash. Our results indicate that without interventions to reduce fire severity, interactions between flammability of regenerating stands and increased extreme fire weather will eliminate much of the remaining mature alpine ash forest. © 2013 John Wiley & Sons Ltd.

  11. Canopy structure and tree condition of young, mature, and old-growth Douglas-fir/hardwood forests

    Science.gov (United States)

    B.B. Bingham; J.O. Sawyer

    1992-01-01

    Sixty-two Douglas-fir/hardwood stands ranging from 40 to 560 years old were used to characterize the density; diameter, and height class distributions of canopy hardwoods and conifers in young (40 -100 yr), mature (101 - 200 yr) and old-growth (>200 yr) forests. The crown, bole, disease, disturbance, and cavity conditions of canopy conifers and hardwoods were...

  12. Nutrient imbalance in Norway spruce

    International Nuclear Information System (INIS)

    Thelin, Gunnar

    2000-11-01

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  13. Nutrient imbalance in Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar

    2000-11-01

    The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met. The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable. Countermeasures are needed in order to maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the need for

  14. Differences in top-soil features between beech-mixture and Norway spruce forests of the Šumava Mts

    Czech Academy of Sciences Publication Activity Database

    Matějka, K.; Starý, Josef

    2009-01-01

    Roč. 55, č. 12 (2009), s. 540-555 ISSN 1212-4834 R&D Projects: GA ČR GA206/07/1200 Institutional research plan: CEZ:AV0Z60660521 Keywords : ash content * Bohemia Forest * element content (P, Ca, Mg, Fe, Al) Subject RIV: EH - Ecology, Behaviour

  15. Interactive effects of wildfire and permafrost on microbial communities and soil processes in an Alaskan black spruce forest.

    Science.gov (United States)

    Mark P. Waldrop; Jennifer W. Harden

    2008-01-01

    Boreal forests contain significant quantities of soil carbon that may be oxidized to CO2 given future increases in climate warming and wildfire behavior. At the ecosystem scale, decomposition and heterotrophic respiration are strongly controlled by temperature and moisture, but we questioned whether changes in microbial biomass, activity, or...

  16. Early lessons from commercial thinning in a 30-year-old Sitka Spruce-Western Hemlock forest.

    Science.gov (United States)

    Sarah E. Greene; William H. Emmingham

    1986-01-01

    A commercial thinning study was undertaken in a 30-year-old stand, pre-commercially thinned at 15 years of age, at Cascade Head Experimental Forest on the Oregon coast. Measurements obtained after three different thinning treatments are presented and include stand volume, basal area, current growth rate, scar damage, crown ratio, and sapwood radius. Method of...

  17. Analysis of Coniferous Forest Damage: Effects of Trichloroacetic Acid, Sulphur, Fluorine and Chlorine on Needle Loss of Norway Spruce

    Czech Academy of Sciences Publication Activity Database

    Coufal, D.; Matucha, Miroslav; Uhlířová, H.; Lomský, B.; Forczek, Sándor

    2003-01-01

    Roč. 13, - (2003), s. 89-102 ISSN 1210-0552 R&D Projects: GA ČR GA522/02/0874 Institutional research plan: CEZ:AV0Z5038910 Keywords : Forest decline * polyfactorial problem * dose/response relationship Subject RIV: EF - Botanics

  18. Abiotic and Biotic Soil Characteristics in Old Growth Forests and Thinned or Unthinned Mature Stands in Three Regions of Oregon

    Directory of Open Access Journals (Sweden)

    David A. Perry

    2012-09-01

    Full Text Available We compared forest floor depth, soil organic matter, soil moisture, anaerobic mineralizable nitrogen (a measure of microbial biomass, denitrification potential, and soil/litter arthropod communities among old growth, unthinned mature stands, and thinned mature stands at nine sites (each with all three stand types distributed among three regions of Oregon. Mineral soil measurements were restricted to the top 10 cm. Data were analyzed with both multivariate and univariate analyses of variance. Multivariate analyses were conducted with and without soil mesofauna or forest floor mesofauna, as data for those taxa were not collected on some sites. In multivariate analysis with soil mesofauna, the model giving the strongest separation among stand types (P = 0.019 included abundance and richness of soil mesofauna and anaerobic mineralizable nitrogen. The best model with forest floor mesofauna (P = 0.010 included anaerobic mineralizable nitrogen, soil moisture content, and richness of forest floor mesofauna. Old growth had the highest mean values for all variables, and in both models differed significantly from mature stands, while the latter did not differ. Old growth also averaged higher percent soil organic matter, and analysis including that variable was significant but not as strong as without it. Results of the multivariate analyses were mostly supported by univariate analyses, but there were some differences. In univariate analysis, the difference in percent soil organic matter between old growth and thinned mature was due to a single site in which the old growth had exceptionally high soil organic matter; without that site, percent soil organic matter did not differ between old growth and thinned mature, and a multivariate model containing soil organic matter was not statistically significant. In univariate analyses soil mesofauna had to be compared nonparametrically (because of heavy left-tails and differed only in the Siskiyou Mountains, where

  19. Forest biomass carbon stocks and variation in Tibet's carbon-dense forests from 2001 to 2050.

    Science.gov (United States)

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-10-05

    Tibet's forests, in contrast to China's other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet's forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr -1 between 2001 and 2010 and a decrease of 1.9 Tg C yr -1 between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet's mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity.

  20. See the forest for the trees: Whole-plant allocation patterns and regulatory mechanisms in Norway spruce

    Science.gov (United States)

    Huang, Jianbei; Behrendt, Thomas; Hammerbacher, Almuth; Weinhold, Alexander; Hellén, Heidi; Reichelt, Michael; Wisthaler, Armin; Dam, Nicole; Trumbore, Susan; Hartmann, Henrik

    2017-04-01

    For more than 40 years plant carbon (C) allocation have been of central interest to plant scientists. Most studies on C allocation focus on either biomass partitioning (e.g., root:shoot ratios), particular fluxes (e.g., non-structural carbohydrate, NSC; biogenic emissions of volatile organic compounds, VOCs) or short-term proportional allocation patterns (e.g., pulse-chase studies using isotopic tracers). However, a thorough understanding of C allocation priorities, especially at the whole-plant level, requires assessing all of these aspects together. We investigated C allocation trade-off in Norway spruce (Picea abies) saplings by assessing whole-plant fluxes (assimilation, respiration and VOCs) and biomass partitioning (structural biomass; NSC; secondary metabolites, SMs). The study was carried out over 8 weeks and allowed us, by modifying atmospheric CO2 concentrations ([CO2]), manipulating plant carbon (C) availability. Treatments included control (400 ppm), carbon compensation (down to 120 ppm) and starvation (down to 50 ppm) C availability levels. Reductions in [CO2] aimed to reveal plant allocation strategies assuming that pools receiving more C than others under C limitation have a high allocation priority. Respiration was less sensitive to declining [CO2] compared to assimilation, NSC and SMs. Strong declines in NSC at low [CO2] suggest that respiration was maintained by using stored NSC. Furthermore, reduced NSC and SMs concentrations also indicate preferential C allocation to growth over NSC and SMs at low C availability. SMs decreased to a lesser extent than NSC in old needles, and remained relatively constant in branches until death from starvation. These results suggest that pools of stored NSC may serve as a buffer for respiration or growth under C limitation but also that SMs remain largely inaccessible for metabolism once they are stored in tissues. VOCs emissions, however, showed contrasting responses to [CO2]; oxygenated VOCs (methanol and

  1. Animal vectors of eastern dwarf mistletoe of black spruce.

    Science.gov (United States)

    Michael E. Ostry; Thomas H. Nicholls; D.W. French

    1983-01-01

    Describes a study to determine the importance of animals in the spread of eastern dwarf mistletoe of black spruce. Radio telemetry, banding, and color-marking techniques were used to study vectors of this forest pathogen.

  2. Analysis of Coniferous Forest Damage: Effects of Trichloroacetic Acid, Sulphur, Fluorine and Chlorine on Needle Loss of Norway Spruce

    Czech Academy of Sciences Publication Activity Database

    Coufal, David; Matucha, P.; Uhlířová, H.; Lomský, B.; Forczek, Sándor; Matucha, Miroslav

    2003-01-01

    Roč. 13, č. 1 (2003), s. 89-102 ISSN 1210-0552 R&D Projects: GA ČR GA522/99/1465; GA MŠk OC 274.001 Grant - others:COST(XE) Action 274 TARSKI Institutional research plan: AV0Z1030915 Keywords : forest decline * polyfactorial problem * monitoring * stress factors * dose/response-relationship Subject RIV: BA - General Mathematics

  3. Impact of the heatwave in 2003 on the summer CH4 and N2O budget of a spruce forest ecosystem: A four-year comparison

    Science.gov (United States)

    Lamers, M.; Fiedler, S.; Jungkunst, H. F.; Stahr, K.; Streck, T.

    2009-04-01

    Both CH4 and N2O reduction and oxidation are highly sensitive to variation in soil moisture. Significant changes of net CH4 and total N2O fluxes from soils can therefore be expected to accompany redistribution for precipitation in the course of climate change where more extreme events are predicted for the future. The extreme summer drought in 2003 offered the unique opportunity to study the impact of such events on the emission of greenhouse gases, such as methane or nitrous oxide, under field conditions. The main objective of the present study was to evaluate the impact of the summer drought in 2003 on the net methane and nitrous oxide budget of a spruce forest ecosystem (South-West Germany) with large variation in soil drainage. During the summers of 2000-2004 we measured net CH4 and N2O fluxes (bi)-weekly using the closed-chamber technique for six different soil types ranging from well-aerated Cambisols to poorly drained Gleysols and a wet Histosol. With regard to CH4 the extreme summer draught (1) did not elevate net CH4-sink function of soils, but (2) highly reduced net CH4-source strength and (3) reversed the net CH4 source of the investigated catchment into a sink. In all four summers investigated, net ecosystem exchange of CH4 was found only in the hydromorphic soils but not in the dominant well-aerated soils. This highlighted the key role of hydromorphic soils for the investigated pedodiverse system. With regard to N2O the summer draught in 2003 significantly reduced N2O emissions at least for the Humic Gleysol and the Sapric Histosol and hence markedly reduced the net N2O source strength of the investigated ecosystem.

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

    Science.gov (United States)

    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

  5. BIOACTIVE COMPOUNDS DURING THE MATURATION OF FOUR FRUITS NATIVE TO THE RESTINGA FOREST OF CEARA

    Directory of Open Access Journals (Sweden)

    NIGÉRIA PEREIRA GONÇALVES

    2017-12-01

    Full Text Available ABSTRACT Fruits provide not only essential nutrients for food, but also bioactive compounds that promote health benefits and help reducing the risk of developing non-communicable chronic diseases. In this sense, this work aimed at quantifying bioactive compounds during the maturation of four fruits native to the Restinga forest of Ceara. Myrtle fruits (Eugenia punicifolia (Kunth DC. were collected at the Botanical State Park of Ceara, Caucaia-CE, and guajiru (Chrisobalanus icaco L., manipuça (Mouriri cearensis Huber and murici-pitanga fruits (Byrsonima gardneriana A. Juss. at the Botanical Garden of São Gonçalo, São Gonçalo do Amarante-CE. Fruits were collected at different stages (E and transported to the Laboratory of Plant Ecophysiology, being characterized into five or six maturation stages according to the bark color, then processed and frozen for the following physicochemical and chemical evaluations: ascorbic acid, total chlorophyll, total carotenoids, total anthocyanins and yellow flavonoids. A completely randomized design was used, with five or six treatments, depending on the maturation stages of fruits and four replicates. Murici-pitanga had higher contents of ascorbic acid (ascorbic acid 646.23 mg/100 g E5, total carotenoids (6.13 mg/100 g E5 and total anthocyanins (7.99 mg/100 g E2; and myrtle had higher contents of total chlorophyll (11.05 mg/100 g E1 and yellow flavonoid (69.11 mg/100 g E2. There are positive and significant correlations between chlorophyll and carotenoid (R= 0.99; P <0.01 for manipuça and between anthocyanin and yellow flavonoid (R= 0.97; P <0.05 for murici-pitanga fruits; however, the correlation is negative and significant between ascorbic acid and yellow flavonoids (R= -0.98; P <0.05 for myrtle fruits. It could be concluded that murici-pitanga and myrtle fruits had the highest contents of bioactive compounds with the highest levels, therefore both fruits can be recommended to be commercially exploited by

  6. Sense of Well-Being in Patients with Fibromyalgia: Aerobic Exercise Program in a Mature Forest A Pilot Study

    OpenAIRE

    López-Pousa, Secundino; Bassets Pagès, Glòria; Monserrat-Vila, Sílvia; Gracia Blanco, Manuel de; Hidalgo Colomé, Jaume; Garre-Olmo, Josep

    2015-01-01

    Background and Objective. Most patients with fibromyalgia benefit from different forms of physical exercise. Studies show that exercise can help restore the body's neurochemical balance and that it triggers a positive emotional state. So, regular exercise can help reduce anxiety, stress, and depression. The aim of this study was to analyze the benefits of moderate aerobic exercise when walking in two types of forests, young and mature, and to assess anxiety, sleep, pain, and well-being in pat...

  7. Carbon dynamics of mature and regrowth tropical forests derived from a pantropical database (TropForC-db).

    Science.gov (United States)

    Anderson-Teixeira, Kristina J; Wang, Maria M H; McGarvey, Jennifer C; LeBauer, David S

    2016-05-01

    Tropical forests play a critical role in the global carbon (C) cycle, storing ~45% of terrestrial C and constituting the largest component of the terrestrial C sink. Despite their central importance to the global C cycle, their ecosystem-level C cycles are not as well-characterized as those of extra-tropical forests, and knowledge gaps hamper efforts to quantify C budgets across the tropics and to model tropical forest-climate interactions. To advance understanding of C dynamics of pantropical forests, we compiled a new database, the Tropical Forest C database (TropForC-db), which contains data on ground-based measurements of ecosystem-level C stocks and annual fluxes along with disturbance history. This database currently contains 3568 records from 845 plots in 178 geographically distinct areas, making it the largest and most comprehensive database of its type. Using TropForC-db, we characterized C stocks and fluxes for young, intermediate-aged, and mature forests. Relative to existing C budgets of extra-tropical forests, mature tropical broadleaf evergreen forests had substantially higher gross primary productivity (GPP) and ecosystem respiration (Reco), their autotropic respiration (Ra) consumed a larger proportion (~67%) of GPP, and their woody stem growth (ANPPstem) represented a smaller proportion of net primary productivity (NPP, ~32%) or GPP (~9%). In regrowth stands, aboveground biomass increased rapidly during the first 20 years following stand-clearing disturbance, with slower accumulation following agriculture and in deciduous forests, and continued to accumulate at a slower pace in forests aged 20-100 years. Most other C stocks likewise increased with stand age, while potential to describe age trends in C fluxes was generally data-limited. We expect that TropForC-db will prove useful for model evaluation and for quantifying the contribution of forests to the global C cycle. The database version associated with this publication is archived in Dryad (DOI

  8. Forest biomass carbon stocks and variation in Tibet’s carbon-dense forests from 2001 to 2050

    Science.gov (United States)

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-01-01

    Tibet’s forests, in contrast to China’s other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet’s forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr−1 between 2001 and 2010 and a decrease of 1.9 Tg C yr−1 between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet’s mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity. PMID:27703215

  9. Parameter-induced uncertainty quantification of soil N2O, NO and CO2 emission from Höglwald spruce forest (Germany using the LandscapeDNDC model

    Directory of Open Access Journals (Sweden)

    K. Butterbach-Bahl

    2012-10-01

    Full Text Available Assessing the uncertainties of simulation results of ecological models is becoming increasingly important, specifically if these models are used to estimate greenhouse gas emissions on site to regional/national levels. Four general sources of uncertainty effect the outcome of process-based models: (i uncertainty of information used to initialise and drive the model, (ii uncertainty of model parameters describing specific ecosystem processes, (iii uncertainty of the model structure, and (iv accurateness of measurements (e.g., soil-atmosphere greenhouse gas exchange which are used for model testing and development. The aim of our study was to assess the simulation uncertainty of the process-based biogeochemical model LandscapeDNDC. For this we set up a Bayesian framework using a Markov Chain Monte Carlo (MCMC method, to estimate the joint model parameter distribution. Data for model testing, parameter estimation and uncertainty assessment were taken from observations of soil fluxes of nitrous oxide (N2O, nitric oxide (NO and carbon dioxide (CO2 as observed over a 10 yr period at the spruce site of the Höglwald Forest, Germany. By running four independent Markov Chains in parallel with identical properties (except for the parameter start values, an objective criteria for chain convergence developed by Gelman et al. (2003 could be used. Our approach shows that by means of the joint parameter distribution, we were able not only to limit the parameter space and specify the probability of parameter values, but also to assess the complex dependencies among model parameters used for simulating soil C and N trace gas emissions. This helped to improve the understanding of the behaviour of the complex LandscapeDNDC model while simulating soil C and N turnover processes and associated C and N soil-atmosphere exchange. In a final step the parameter distribution of the most sensitive parameters determining soil-atmosphere C and N exchange were used to obtain

  10. Applicability of non-destructive substitutes for leaf area in different stands of Norway spruce (Picea abies L. Karst.) focusing on traditional forest crown measures

    Science.gov (United States)

    Laubhann, Daniel; Eckmüllner, Otto; Sterba, Hubert

    2010-01-01

    Since individual tree leaf area is an important measure for productivity as well as for site occupancy, it is of high interest in many studies about forest growth. The exact determination of leaf area is nearly impossible. Thus, a common way to get information about leaf area is to use substitutes. These substitutes are often variables which are collected in a destructive way which is not feasible for long term studies. Therefore, this study aimed at testing the applicability of using substitutes for leaf area which could be collected in a non-destructive way, namely crown surface area and crown projection area. In 8 stands of Norway spruce (Picea abies L. Karst.), divided into three age classes and two thinning treatments, a total of 156 trees were felled in order to test the relationship between leaf area and crown surface area and crown projection area, respectively. Individual tree leaf area of the felled sample trees was estimated by 3P-branch sampling with an accuracy of ±10%. Crown projection area and crown surface area were compared with other, more commonly used, but destructive predictors of leaf area, namely sapwood area at different heights on the bole. Our investigations confirmed findings of several studies that sapwood area is the most precise measure for leaf area because of the high correlation between sapwood area and the leaf area. But behind sapwood area at crown base and sapwood area at three tenth of the tree height the predictive ability of crown surface area was ranked third and even better than that of sapwood area at breast height (R2 = 0.656 compared with 0.600). Within the stands leaf area is proportional to crown surface area. Using the pooled data of all stands a mixed model approach showed that additionally to crown surface area dominant height and diameter at breast height (dbh) improved the leaf area estimates. Thus, taking dominant height and dbh into account, crown surface area can be recommended for estimating the leaf area of

  11. Applicability of non-destructive substitutes for leaf area in different stands of Norway spruce (Picea abies L. Karst.) focusing on traditional forest crown measures.

    Science.gov (United States)

    Laubhann, Daniel; Eckmüllner, Otto; Sterba, Hubert

    2010-09-30

    Since individual tree leaf area is an important measure for productivity as well as for site occupancy, it is of high interest in many studies about forest growth. The exact determination of leaf area is nearly impossible. Thus, a common way to get information about leaf area is to use substitutes. These substitutes are often variables which are collected in a destructive way which is not feasible for long term studies. Therefore, this study aimed at testing the applicability of using substitutes for leaf area which could be collected in a non-destructive way, namely crown surface area and crown projection area. In 8 stands of Norway spruce (Picea abies L. Karst.), divided into three age classes and two thinning treatments, a total of 156 trees were felled in order to test the relationship between leaf area and crown surface area and crown projection area, respectively. Individual tree leaf area of the felled sample trees was estimated by 3P-branch sampling with an accuracy of ±10%. Crown projection area and crown surface area were compared with other, more commonly used, but destructive predictors of leaf area, namely sapwood area at different heights on the bole. Our investigations confirmed findings of several studies that sapwood area is the most precise measure for leaf area because of the high correlation between sapwood area and the leaf area. But behind sapwood area at crown base and sapwood area at three tenth of the tree height the predictive ability of crown surface area was ranked third and even better than that of sapwood area at breast height (R(2) = 0.656 compared with 0.600). Within the stands leaf area is proportional to crown surface area. Using the pooled data of all stands a mixed model approach showed that additionally to crown surface area dominant height and diameter at breast height (dbh) improved the leaf area estimates. Thus, taking dominant height and dbh into account, crown surface area can be recommended for estimating the leaf area

  12. Damage to spruce stands by deer barking and subsequent rots in Forest Range Proklest, the Křtiny Training Forest Enterprise “Masaryk Forest” (the Drahany Upland

    Directory of Open Access Journals (Sweden)

    Petr Čermák

    2004-01-01

    Full Text Available The paper deals with determination of the rate of damage by red deer barking, determination of the rate of damage by a subsequent rot caused by Stereum sanguinolentum and the rate of its progress. The paper elucidates causes of the damage and quantifies depreciation of wood by rots in the Proklest Forest Range, the Křtiny Training Forest Enterprise “Masaryk Forest“. The deer barking caused damage to 85% of stands. In the most damaged 2nd and 4th age classes, rot caused by Stereum sanguinolentum was noticed in 89% of damaged trees. The greatest proportion is made by damage from the 70s of the last century. After the 80s, the damage occurred only exceptionally. The average percentage loss of wood is highest in the 2nd age class, viz. 38%. The determined progress of the rot ranged from 1 to 36.4 cm.year-1.

  13. Effects of air pollution and climatic factors on Norway spruce forests in the Orlicke hory Mts. (Czech Republic), 1979-2014

    Science.gov (United States)

    Stanislav Vacek; Iva Hunova; Zdenek Vacek; Pavla Hejcmanova; Vilem Podrazsky; Jan Kral; Tereza Putalova; W. Keith Moser

    2015-01-01

    The area of the Orlicke hory Mts. has been characterised by decline and disturbances of Norway spruce (Picea abies/L./Karst.) stands since the 1980s. Currently, only three permanent research plots have been preserved from the original sixteen established plots in this region. In the present study, the health status, as indicated by defoliation, mortality, and...

  14. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure

    Science.gov (United States)

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respira...

  15. Analysis of the Soil Organic Matter Stability in Spruce Forests of Krkonose in Czechia on the Basis of the ROMUL Mathematical Model

    Czech Academy of Sciences Publication Activity Database

    Nadporozhskaya, M.A.; Cudlín, Pavel; Novák, František; Bykhovets, S.S.; Chertov, O.G.; Komarov, A.S.; Mikhailov, A.V.

    2009-01-01

    Roč. 42, č. 6 (2009), s. 657-667 ISSN 1064-2293 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z60660521 Keywords : Norway spruce * model ROMUL * soil organic matter Subject RIV: DF - Soil Science Impact factor: 0.222, year: 2009

  16. Risk evaluation of the climatic change impact on secondary Norway spruce stands as exemplified by the Křtiny Training Forest Enterprise

    Czech Academy of Sciences Publication Activity Database

    Čermák, P.; Jankovský, L.; Cudlín, Pavel

    2004-01-01

    Roč. 50, č. 6 (2004), s. 256-262 ISSN 1212-4834 R&D Projects: GA MŠk OC E27.001 Institutional research plan: CEZ:AV0Z6087904 Keywords : climatic change * Norway spruce * risk assessment Subject RIV: GK - Forestry

  17. Breeding avifauna of mature forest stands in the Borki Forest and its dynamics at the turn of the 21st century

    Directory of Open Access Journals (Sweden)

    Rąkowski Grzegorz

    2016-09-01

    Full Text Available The composition and structure of the breeding bird community in the Borki Forest in north-eastern Poland were investigated during two separate periods: 1994–1996 and 2012–2014. Bird censuses were carried out in three plots located in mature oak-hornbeam, ash-alder and mixed coniferous forest stands. A standard combined mapping technique for estimating the number of breeding birds was applied. A total of 74 bird species bred at least once within any plot during 1994–1996 or 2012–2014. The structure of the bird assemblages on particular plots displayed a high degree of similarity, exceeding 75%, which means that they represent essentially the same bird community. However, the investigated assemblages have changed substantially over the 20 years. Both, the number of breeding bird species and the population densities on all plots, were much higher in 2012–2014 than in 1994–1996. The mean number of breeding species on all plots was over 50% higher in 2012–2014 than in 1994–1996, whereas the mean total density of breeding pairs increased by more than 60%. Total population densities on the plots increased as a result of an increase in population densities of individual bird species combined with an increase in the number of breeding species. Due to different rates of population growth for certain species, also the composition of dominating species group have changed. The observed changes in the avifauna of the Borki Forest were most probably due to an enrichment of the forest habitats structure, which was caused by natural factors, such as ageing of forest stands, forest succession and a change in water regime by beaver dams, as well as by forest management, including group felling within or in the vicinity of plots and uncovering of the forest edge.

  18. Soil surface CO2 efflux measurements in Norway spruce forests. Comparison between four different sites across Europe — from boreal to alpine forest

    Czech Academy of Sciences Publication Activity Database

    Acosta, Manuel; Pavelka, Marian; Montagnani, L.; Kutsch, W.; Lindroth, A.; Juszczak, R.; Janouš, Dalibor

    2013-01-01

    Roč. 192, JAN (2013), s. 295-303 ISSN 0016-7061 R&D Projects: GA MŠk OC08021; GA MŽP(CZ) SP/2D1/93/07; GA MŽP(CZ) SP/2D1/70/08; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Soil CO2 efflux * Forest * Chamber method * Q10 * Soil temperature * Spatial variability Subject RIV: EH - Ecology, Behaviour Impact factor: 2.509, year: 2013

  19. CO2-gas-exchange and transpiration of open-grown Norway spruce during the year in higher elevations of the Southern Black Forest under local air-conditions with and without ozone

    International Nuclear Information System (INIS)

    Abetz, P.; Kuenstle, E.; Wolfart, A.

    1993-03-01

    Aim and method: CO 2 -gas-exchange and transpiration of open-grown Norway spruce (about 12 m high) on the top of the Black Forest (1230 m a.s.l.) near Freiburg under local conditions with and without ozone are being continiously measured through the whole year. In the same intensity are registered the temperature of soil, needles, twigs, stem and air, the humidity in soil and air and the diameter-changes of the stem. Nearby other institutions measure the quality of air and depositions. Results: In winter with less snowfall, higher temperature and higher insolation, the youngest twigs of the spruce had a lower net-photosynthesis but a higher respiration at night on the southern part versus nothern part (with more shade). Perhaps it happened an inactivity of the photosynthesis-apparatus because of too high insolation. In the same time the colour of the needles on the southern part changed to yellowish green (on the northern part they remained dark green). During dry summer periods the photosynthesis dropped earlier and deeper. The 'radial-increment' stagnated. There was no difference in the gas-exchange when the ozone concentration had been enlarged, neither in winter nor in summertime. (orig.). 57 figs., 12 tabs., 178 refs [de

  20. Ant-mediated effects on spruce litter decomposition, solution chemistry, and microbial activity

    DEFF Research Database (Denmark)

    Stadler, B.; Schramm, Andreas; Kalbitz, K.

    2006-01-01

    the effects of ants and aphid honeydew on litter solution of Norway spruce, microbial enzyme activities, and needle decomposition in a field and greenhouse experiment during summer 2003. In the field, low ant densities had relatively little effects on litter solution 30 cm away from a tree trunk...... and %N were not affected by ants or honeydew. Our results suggest that ants have a distinct and immediate effect on solution composition and microbial activity in the litter layer indicating accelerated litter decay whereas the effect of honeydew was insignificant. Keywords: Ants; Decomposition; Formica......Forest management practices often generate clear-cut patches, which may be colonized by ants not present in the same densities in mature forests. In addition to the associated changes in abiotic conditions ants can initiate processes, which do not occur in old-growth stands. Here, we analyse...

  1. Nutrient limitation on ecosystem productivity and processes of mature and old-growth subtropical forests in China.

    Directory of Open Access Journals (Sweden)

    Enqing Hou

    Full Text Available Nitrogen (N is considered the dominant limiting nutrient in temperate regions, while phosphorus (P limitation frequently occurs in tropical regions, but in subtropical regions nutrient limitation is poorly understood. In this study, we investigated N and P contents and N:P ratios of foliage, forest floors, fine roots and mineral soils, and their relationships with community biomass, litterfall C, N and P productions, forest floor turnover rate, and microbial processes in eight mature and old-growth subtropical forests (stand age >80 yr at Dinghushan Biosphere Reserve, China. Average N:P ratios (mass based in foliage, litter (L layer and mixture of fermentation and humus (F/H layer, and fine roots were 28.3, 42.3, 32.0 and 32.7, respectively. These values are higher than the critical N:P ratios for P limitation proposed (16-20 for foliage, ca. 25 for forest floors. The markedly high N:P ratios were mainly attributed to the high N concentrations of these plant materials. Community biomass, litterfall C, N and P productions, forest floor turnover rate and microbial properties were more strongly related to measures of P than N and frequently negatively related to the N:P ratios, suggesting a significant role of P availability in determining ecosystem production and productivity and nutrient cycling at all the study sites except for one prescribed disturbed site where N availability may also be important. We propose that N enrichment is probably a significant driver of the potential P limitation in the study area. Low P parent material may also contribute to the potential P limitation. In general, our results provided strong evidence supporting a significant role for P availability, rather than N availability, in determining ecosystem primary productivity and ecosystem processes in subtropical forests of China.

  2. Warmer temperatures reduce net carbon uptake, but not water use, in a mature southern Appalachian forest

    Science.gov (United States)

    Increasing air temperature is expected to extend growing season length in temperate, broadleaf forests, leading to potential increases in evapotranspiration and net carbon uptake. However, other key processes affecting water and carbon cycles are also highly temperature-dependent...

  3. Cold tolerance and photosystem function in a montane red spruce population: physiological relationships with foliar carbohydrates

    Science.gov (United States)

    P.G. Shaberg; G.R. Strimbeck; G.J. Hawley; D.H. DeHayes; J.B. Shane; P.F. Murakami; T.D. Perkins; J.R. Donnelly; B.L. Wong

    2000-01-01

    Red spruce (Picea rubens Sarg.) growing in northern montane forests of eastern North America appears to be distinctive with respect to at least two aspects of winter physiology. First, red spruce attains only a modest level of midwinter cold tolerance compared to other north temperate conifers and appears barely capable of avoiding freezing injury at...

  4. The state of the forest ecosystem in an area of oil shale mining and processing. 2. Morphological characteristics of Norway spruce

    International Nuclear Information System (INIS)

    Ots, K.; Rauk, J.; Mandre, M.

    2000-01-01

    Air pollutants (oil shale fly ash, gases, organic compounds) emitted by the oil shale industry in Kohtla-Jaerve, North-East Estonia, have caused changes in the soil (pH = 4.7-7.4), subsoil water (pH = 5.9-7.2), rainwater (pH = 7.0-7. 1) and snow melt (pH = 7.3-8.7) compared with an unpolluted control area in Lahemaa National Park (soil pH = 3.6, subsoil water pH = 5. 1, rainwater pH = 6.9 and snow melt pH = 6.8). Compared with the period before 1990 the pollution load on the area investigated has fallen drastically; however, this has not resulted in an essential improvement in growth conditions of trees. Morphological analysis of 80-year-old Norway spruces growing on sampling plots (six) in the polluted area and in the control area showed that air pollution has had temporally (1989-1990, 1994-1996) and spatially variable effect on the parameters characterising the state of trees: length growth, weight and dry matter content of needles and shoots, number and density of needles on shoots, radial increment of trees. The length growth of needles and shoots proved to be one of the most suitable parameters indicating the influence of air pollution, although not in all sample plots investigated. The results for fresh and dry weight of needles revealed great differences between sampling plots. The biomass of shoots was notably greater in the immediate vicinity of Kohtla-Jaerve than in the control area. The spruces whose shoots showed inhibited length growth had greater density of needles on shoots with difference from the control being up to 16 Olo. The effect on the radial increment of Norway spruces was especially strong in the immediate vicinity of pollution sources (<2 km) but it fell rapidly with distance from them. (author)

  5. Aquatic insect emergence from headwater streams flowing through regeneration and mature forests in western Oregon

    Science.gov (United States)

    Robert Progar; Andrew R. Moldenke

    2009-01-01

    We examined the effect of canopy cover on adult aquatic insect emergence by collecting bi-weekly samples from twelve headwater stream reaches flowing either under a mature conifer canopy or streams flowing through ten-year-old regeneration in western Oregon from February to November 1997. Density and biomass generally followed a bimodal curve with peaks during early...

  6. Dispersal of forest insects

    Science.gov (United States)

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  7. Two-dimensional wavelet analysis of spruce budworm host basal area in the Border Lakes landscape

    Science.gov (United States)

    Patrick M. James; Brian R. Sturtevant; Phil Townsend; Pete Wolter; Marie-Josee. Fortin

    2011-01-01

    Increases in the extent and severity of spruce budworm (Choristoneura fumiferana Clem.) outbreaks over the last century are thought to be the result of changes in forest structure due to forest management. A corollary of this hypothesis is that manipulations of forest structure and composition can be used to reduce future forest vulnerability....

  8. Monitoring tree mortality in mature Douglas-fir forests: size and species matter

    Science.gov (United States)

    Background/Question/MethodsA regional increase in tree mortality rates associated with climate change will influence forest health and ecosystem services, including water quality and quantity. In recent decades, accelerated tree mortality has occurred in some, but not all, fores...

  9. First results about effects of liming on saprophytic fungal communities in the Ah-horizon of a spruce forest soil in France (Vosges); Erste Resultate ueber den Effekt von Kalkung auf die Pilzpopulation (Saprophyten) im Ah-Horizont eines Fichtenwaldbodens in Frankreich (Vogesen)

    Energy Technology Data Exchange (ETDEWEB)

    Devevre, O [Centre I.N.R.A. de Nancy, Lab. de Microbiologie Forestiere, 54 - Champenoux (France); Roquebert, M F [Musee National d` Histoire Naturelle, Lab. de Cryptogamie, 75 - Paris (France); Garbaye, J [Centre I.N.R.A. de Nancy, Lab. de Microbiologie Forestiere, 54 - Champenoux (France)

    1993-04-01

    Soil fungi, including mycorrhiza, are strongly affected by zoil chemical parameters such as the ratio of calcium and/or magnesium to aluminium and the pH-value. So, it was very interesting to compare the rhizospheric microfungal flora between a declining spruce stand and a healthy spruce stand. The site chosen for this investigation was situated in the Vosges in the northeast of France. The rhizospheric soil, from the Ah-horizon of a sandy loam podzol, limed (the healthy spruce stand) or unlimed (the declining spruce stand) was sampled in a 65-year-old Norway spruce forest. The study was made 7 years after liming. Fungal isolations were performed using the dilution plate method. Pronounced differences in species abundance and composition were found between the limed and the unlimed stands. Of the 49 isolated species (24 from declining spruce plot and 34 from healthy spruce plot) only nine were found at both plots. The greatest diversity is observed at the healthy spruce stand; it may be due to the liming. This study indicates that soil microfungi could be sensitive to increased acidity of the rain with subsequent effects. (orig.) [Deutsch] Bodenpilze einschliesslich der Mykorrhizapilze sind stark von bodenchemischen Parameters wie dem Verhaeltnis von Calcium und/oder Magnesium zu Aluminium sowie vom pH-Wert des Bodens abhaengig. Deshalb wurde die Pilzmikroflora eines geschaedigten Fichtenbestand mit einem gesunden Fichtenbestand in den Vogesen, im Nordosten Frankreichs verglichen. In einem 65jaehrigen Fichtenbestand wurde der durchwurzelte Boden des Ah-Horizontes eines sandig-lehmigen Podsols einer gekalkten (gesunder Fichtenbestand) sowie einer ungekalkten Parzelle (geschaedigter Fichtenbestand) beprobt. Die Studie wurde 7 Jahre nach der Kalkung durchgefuehrt. Die Isolation der Pilze wurde anhand der Verduennungstechnik auf Kulturmedium mit DRBC-Agar durchgefuehrt. Sowohl im Artenvorkommen als auch in den Populationsstaerken bestanden betraechtliche Unterschiede

  10. Conservation of element concentration in xylem sap of red spruce

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle

    2001-01-01

    We investigated the chemistry of xylem sap as a marker of red spruce metabolism and soil chemistry at three locations in northern New England. A Scholander pressure chamber was used to extract xylem sap from roots and branches cut from mature trees in early June and September. Root sap contained significantly greater concentrations of K, Ca, Mg, Mn, and A1 than branch...

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

    Directory of Open Access Journals (Sweden)

    N. Yassaa

    2012-08-01

    Full Text Available 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

  12. Logging residue removal after thinning in boreal forests: long-term impact on the nutrient status of Norway spruce and Scots pine needles.

    Science.gov (United States)

    Luiro, Jukka; Kukkola, Mikko; Saarsalmi, Anna; Tamminen, Pekka; Helmisaari, Heljä-Sisko

    2010-01-01

    The aim of this study was to compare how conventional stem harvesting (CH) and whole-tree harvesting (WTH) in the first, and in some cases also in the second, thinning affect the needle nutrient status of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) stands in Finland. A series of 12 long-term field experiments was studied. The experiments were established during 1978-86. The effects of logging residue removal after thinnings on the needle nutrient concentrations were generally minor and without any overall trends, but there were differences between experiments. Trees tend to maintain their current needle nutrient concentrations at the same level by re-utilizing the nutrients stored in the older tissues and by changing C allocation in the whole tree. Thus, needle analysis should be combined with stem growth data in order to achieve a more comprehensive understanding of the effects of WTH on the nutrient status of trees.

  13. Tree mortality in mature riparian forest: Implications for Fremont cottonwood conservation in the American southwest

    Science.gov (United States)

    Andersen, Douglas

    2015-01-01

    Mature tree mortality rates are poorly documented in desert riparian woodlands. I monitored deaths and calculated annual survivorship probability (Ps) in 2 groups of large (27–114 cm DBH), old (≥40 years old) Fremont cottonwood (Populus fremontii Wats.) in a stand along the free-flowing Yampa River in semiarid northwestern Colorado. Ps = 0.993 year-1 in a group (n = 126) monitored over 2003–2013, whereas Ps = 0.985 year-1 in a group (n = 179) monitored over the same period plus 3 earlier years (2000–2003) that included drought and a defoliating insect outbreak. Assuming Ps was the same for both groups during the 10-year postdrought period, the data indicate that Ps = 0.958 year-1 during the drought. I found no difference in canopy dieback level between male and female survivors. Mortality was equal among size classes, suggesting Ps is independent of age, but published longevity data imply that either Ps eventually declines with age or, as suggested in this study, periods with high Ps are interrupted by episodes of increased mortality. Stochastic population models featuring episodes of low Ps suggest a potential for an abrupt decline in mature tree numbers where recruitment is low. The modeling results have implications for woodland conservation, especially for relictual stands along regulated desert rivers.

  14. Quantifying climate-growth relationships at the stand level in a mature mixed-species conifer forest.

    Science.gov (United States)

    Teets, Aaron; Fraver, Shawn; Weiskittel, Aaron R; Hollinger, David Y

    2018-03-11

    A range of environmental factors regulate tree growth; however, climate is generally thought to most strongly influence year-to-year variability in growth. Numerous dendrochronological (tree-ring) studies have identified climate factors that influence year-to-year variability in growth for given tree species and location. However, traditional dendrochronology methods have limitations that prevent them from adequately assessing stand-level (as opposed to species-level) growth. We argue that stand-level growth analyses provide a more meaningful assessment of forest response to climate fluctuations, as well as the management options that may be employed to sustain forest productivity. Working in a mature, mixed-species stand at the Howland Research Forest of central Maine, USA, we used two alternatives to traditional dendrochronological analyses by (1) selecting trees for coring using a stratified (by size and species), random sampling method that ensures a representative sample of the stand, and (2) converting ring widths to biomass increments, which once summed, produced a representation of stand-level growth, while maintaining species identities or canopy position if needed. We then tested the relative influence of seasonal climate variables on year-to-year variability in the biomass increment using generalized least squares regression, while accounting for temporal autocorrelation. Our results indicate that stand-level growth responded most strongly to previous summer and current spring climate variables, resulting from a combination of individualistic climate responses occurring at the species- and canopy-position level. Our climate models were better fit to stand-level biomass increment than to species-level or canopy-position summaries. The relative growth responses (i.e., percent change) predicted from the most influential climate variables indicate stand-level growth varies less from to year-to-year than species-level or canopy-position growth responses. By

  15. Canopy gaps affect long-term patterns of tree growth and mortality in mature and old-growth forests in the Pacific Northwest

    Science.gov (United States)

    Andrew N. Gray; Thomas A. Spies; Robert J. Pabst

    2012-01-01

    Canopy gaps created by tree mortality can affect the speed and trajectory of vegetation growth. Species’ population dynamics, and spatial heterogeneity in mature forests. Most studies focus on plant development within gaps, yet gaps also affect the mortality and growth of surrounding trees, which influence shading and root encroachment into gaps and determine whether,...

  16. Disking and mid- and understory removal following an above-average acorn crop in three mature oak forests in southern Indiana

    Science.gov (United States)

    Ronald A. Rathfon; Nathanael I. Lichti; Robert K. Swihart

    2008-01-01

    We disked using small-scale equipment in the understory of three mature upland oak (Quercus) forests in southern Indiana immediately following acorn dispersal in an aboveaverage seed crop year as a means of improving oak seedling establishment. Three different mid- and understory removal treatments were also applied to create favorable light...

  17. Resolving model parameter values from carbon and nitrogen stock measurements in a wide range of tropical mature forests using nonlinear inversion and regression trees

    Science.gov (United States)

    Shuguang Liua; Pamela Anderson; Guoyi Zhoud; Boone Kauffman; Flint Hughes; David Schimel; Vicente Watson; Joseph. Tosi

    2008-01-01

    Objectively assessing the performance of a model and deriving model parameter values from observations are critical and challenging in landscape to regional modeling. In this paper, we applied a nonlinear inversion technique to calibrate the ecosystem model CENTURY against carbon (C) and nitrogen (N) stock measurements collected from 39 mature tropical forest sites in...

  18. Optimal uneven-aged stocking guides: an application to spruce-fir stands in New England

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey

    2014-01-01

    Management guides for uneven-aged forest stands periodically need to be revisited and updated based on new information and methods. The current silvicultural guide for uneven-aged spruce-fir management in Maine and the northeast (Frank, R.M. and Bjorkbom, J.C. 1973 A silvicultural guide for spruce-fir in the northeast. General Technical Report NE-6, Forest Service. U.S...

  19. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    Science.gov (United States)

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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

  1. Animal damage to young spruce and fir in Maine

    Science.gov (United States)

    Barton M. Blum

    1977-01-01

    The loss of terminal buds on small balsam fir (Abies balsamea (L.) Mill.) and spruce (Picea spp.) trees because of nipping by mammals or birds has increased on the Penobscot Experimental Forest in recent years. The cut stem is smooth and slightly angled; there is no sign of tearing. Unnipped trees grew about 13 percent more than...

  2. Dynamics of calcium concentration in stemwood of red spruce and Siberian fir

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Rakesh Minocha; Vladislav A. Alexeyev

    1996-01-01

    The atmospheric deposition of strong acid anions such as sulfate and nitrate shifts the ion exchange equilibrium in the rooting zone of sensitive forests. Red spruce and other northern coniferous forests are especially sensitive to deposition due to the shallow rooting of trees in a mor-type forest floor. Initially, the deposition of strong acid ions mobilizes...

  3. The incidence of dwarf mistletoe in Minnesota black spruce stands detected by operational inventories

    Science.gov (United States)

    Fred Baker; Mark Hansen; John D. Shaw; Manfred Mielke; Dixon Shelstad

    2012-01-01

    We surveyed black spruce stands within 0.5 miles of US Forest Service Forest Inventory and Analysis (FIA) plots and compared dwarf mistletoe status with that of the FIA and Minnesota Department of Natural Resources (DNR) forest inventories. Our results differed from FIA results in 3 of 16 stands with FIA plots, with FIA most often not recording dwarf mistletoe in...

  4. In-stand scenic beauty of variable retention harvests and mature forests in the U.S. Pacific Northwest: the effects of basal area, density, retention pattern and down wood

    Science.gov (United States)

    R.G. Ribe

    2009-01-01

    Tensions between amenity- and timber-based economies in the U.S. and Canadian Pacific Northwest motivated a study of scenic beauty inside mature forests and timber harvests. A diverse sample of regional forests, measures of forest structure, and large, representative samples of photographs and public judges were employed to measure scenic beauty inside unharvested...

  5. Release of suppressed red spruce using canopy gap creation—Ecological restoration in the Central Appalachians

    Science.gov (United States)

    Rentch, J.S.; Ford, W. Mark; Schuler, T.S.; Palmer, J.; Diggins, Corinne A.

    2016-01-01

    Red spruce (Picea rubens) and red spruce-northern hardwood mixed stands once covered as much as 300,000 ha in the Central Appalachians, but now comprise no more than 21,000 ha. Recently, interest in restoration of this forest type has increased because red spruce forests provide habitat for a number of rare animal species. Our study reports the results of an understory red spruce release experiment in hardwood-dominated stands that have a small component of understory red spruce. In 2005, 188 target spruce were identified in sample plots at six locations in central West Virginia. We projected a vertical cylinder above the crown of all target spruces, and in 2007, we performed a release treatment whereby overtopping hardwoods were treated with herbicide using a stem injection technique. Release treatments removed 0–10% (Control), 11–50% (Low), 51–89% (Medium), and ≤90% (High) of the basal area of overtopping trees. We also took canopy photographs at the time of each remeasurement in 2007, 2010, and 2013, and compared basal removal treatments and resulting 2010 canopy openness and understory light values. The high treatment level provided significantly greater six-year dbh and height growth than the other treatment levels. Based on these results, we propose that a tree-centered release approach utilizing small canopy gaps that emulate the historical, gap-phase disturbance regime provides a good strategy for red spruce restoration in hardwood forests where overstory spruce are virtually absent, and where red spruce is largely relegated to the understory.

  6. Acidification of a white spruce ecosystem in eastern Cape Breton Island

    International Nuclear Information System (INIS)

    Bouman, O.T.

    2005-01-01

    A study was conducted in 2003 at an ecosystem monitoring plot near Sydney, Nova Scotia, in a mature white spruce stand on a Shulie soil. The objective was to examine how spruce forests filter atmospheric sulfur dioxide and become destabilized by the resulting soil acidification. The acid rain problem at the level of input, top soil, sub soil and run off was assessed following results from 4 monitoring stations equipped for bulk sampling of throughfall water and two lysimeters for soil water extraction at a depth of 15 cm and 45 cm, respectively. Rainwater was collected in 2 open areas outside the forest along with samples from a stream draining the forest and surrounding wetland. Water samples were collected 8 times between April 2003 and November 2004. Results show that the problem of acid rain is present in eastern Cape Breton Island. Canopy passage was found to lower the average rainwater pH from 4.7 to 4.2 with a related increase of sulfate from 2.2 ppm to 8.3 ppm. Top soil solution pH was 3.9 increasing to 4.5 in the sub soil. Aluminum was found to increase significantly in the soil solution when pH dropped below 4.2. This demonstrated that soil acidification due to acid rain frees the aluminum in the top soil. However, the concentration of metal was reduced at lower soil depth due to base cation exchange. High sodium concentrations in rainwater and throughfall were closely associated with sulfate values, indicating high inputs of saline oceanic spray with the potential to cause a salt effect in the top soil chemistry. Most water samples had very low nitrate concentrations. The water chemistry in the stream fluctuated with the pH, often dropping below 5 when sulfate contents increased during high run off events

  7. Influence of microhabitats on the performance of herbaceous species in areas of mature and secondary forest in the semiarid region of Brazil

    Directory of Open Access Journals (Sweden)

    Juliana Ramos de Andrade

    2015-06-01

    Full Text Available The conditions for plant establishment in mature forest are different from those found in disturbed areas. In dry environments, the herbaceous cover is the most important in the recolonization of deforested areas. It can, therefore, act as an ideal biological group for assessing how changes in habitat heterogeneity affect the resilience of dry forests. The aim of this research was to evaluate whether natural regeneration of the herbaceous stratum differed between areas of mature and secondary forest of Caatinga and to describe this process. The study took place in the Brazilian semiarid region during the rainy season 2011 (January to August, where fifty 1m² plots were set up, 25 allocated to the microhabitat established as “between canopies” and 25 to the microhabitat “under the canopy”. The herbaceous species selected for the study were Delilia biflora (Asteraceae, Gomphrena vaga (Amaranthaceae and Pseudabutilon spicatum (Malvaceae, abundant species occurring in both areas. All individuals from the selected populations were counted, marked with sequential numbers, and the height of the stem was measured. Differences between areas, and in size and survival between microhabitats, were found only for the first two species. Fruit production was higher in the mature forest for the three species. The study concluded that: 1. The effect of the microhabitats “between canopies” and “under the canopy” in mature and secondary forest areas depends on the species considered; 2. Populations sensitive to light intensity differ in number of individuals, height and fruit production; and 3. The resilience of anthropogenic areas in semiarid environments can be characterized by the presence of spatial heterogeneity with regard to the emergence and survival of herbaceous seedlings, suggesting that the regeneration of disturbed areas may occur in patches. Rev. Biol. Trop. 63 (2: 357-368. Epub 2015 June 01.

  8. Climate-induced mortality of spruce stands in Belarus

    Science.gov (United States)

    Kharuk, Viacheslav I.; Im, Sergei T.; Dvinskaya, Maria L.; Golukov, Alexei S.; Ranson, Kenneth J.

    2015-12-01

    The aim of this work is an analysis of the causes of spruce (Picea abies L.) decline and mortality in Belarus. The analysis was based on forest inventory and Landsat satellite (land cover classification, climate variables (air temperature, precipitation, evaporation, vapor pressure deficit, SPEI drought index)), and GRACE-derived soil moisture estimation (equivalent of water thickness anomalies, EWTA). We found a difference in spatial patterns between dead stands and all stands (i.e., before mortality). Dead stands were located preferentially on relief features with higher water stress risk (i.e., higher elevations, steeper slopes, south and southwestern exposure). Spruce mortality followed a series of repeated droughts between 1990 and 2010. Mortality was negatively correlated with air humidity (r = -0.52), and precipitation (r = -0.57), and positively correlated with the prior year vapor pressure deficit (r = 0.47), and drought increase (r = 0.57). Mortality increased with the increase in occurrence of spring frosts (r = 0.5), and decreased with an increase in winter cloud cover (r = -0.37). Spruce mortality was negatively correlated with snow water accumulation (r = -0.81) and previous year anomalies in water soil content (r = -0.8). Weakened by water stress, spruce stands were attacked by pests and phytopathogens. Overall, spruce mortality in Belarussian forests was caused by drought episodes and drought increase in synergy with pest and phytopathogen attacks. Vast Picea abies mortality in Belarus and adjacent areas of Russia and Eastern Europe is a result of low adaptation of that species to increased drought. This indicates the necessity of spruce replacement by drought-tolerant indigenous (e.g., Pinus sylvestris, Querqus robur) or introduced (e.g., Larix sp. or Pseudotsuga menzieslii) species to obtain sustainable forest growth management.

  9. Vulnerability of the boreal forest to climate change: are managed forests more susceptible?

    International Nuclear Information System (INIS)

    Leduc, A.; Gauthier, S.

    2004-01-01

    This paper postulates that forests dominated by younger seral stages are less vulnerable to climate change that those composed of mature and overmature stands. To support this analysis, an overview of expected changes in climate conditions was provided. Expected changes include higher maximum temperatures, higher minimum temperatures and a decrease in periods of intense cold and fewer frost days; reduction in the diurnal temperature range; an increase in the apparent heat index; greater numbers of intense precipitation; and, increased risk of drought associated with air mass movements. A comparison between conditions in a managed forest mosaic and natural forests was made, with managed forests differing due to efforts to regulate the age structure. The inversion in the age structure of forest mosaics creates significant changes in structural characteristics and composition, including greater hardwood components and more even-aged stands. It was concluded that in Canada, managed boreal forests are younger and have less black spruce and more hardwoods and fir, making younger forests less vulnerable to fire and more amenable to fire control due to increased accessibility. It was also noted that because of their relative youth, managed forests are more vulnerable to regeneration failure and that managed forests with more balsam fir and trembling aspen are at greater risk for insect outbreaks. In addition, wind throw, a threat to older forests, is not significant in managed forests. 15 refs., 1 tab., 2 figs

  10. Drought-triggered western spruce budworm outbreaks in the Interior Pacific Northwest: A multi-century dendrochronological record

    Science.gov (United States)

    A. Flower; D. G. Gavin; E. K. Heyerdahl; R. A. Parsons; G. M. Cohn

    2014-01-01

    Douglas-fir forests in the interior Pacific Northwest are subject to sporadic outbreaks of the western spruce budworm, a species widely recognized as the most destructive defoliator in western North America. Outbreaks of the western spruce budworm often occur synchronously over broad regions and lead to widespread loss of leaf area and decrease in growth rates in...

  11. Effects of soil calcium and aluminum on the physiology of balsam fir and red spruce saplings in northern New England

    Science.gov (United States)

    Richard L. Boyce; Paul G. Schaberg; Gary J. Hawley; Joshua M. Halman; Paula F. Murakami

    2013-01-01

    We examined the influence of calcium (Ca) and aluminum (Al) nutrition on the foliar physiology of red spruce (Picea rubens Sarg.) and balsam fir [Abies balsamea (L.) Mill.] in northern New England, USA. At the Hubbard Brook Experimental Forest (NH, USA), spruce and fir saplings were sampled from control, Al-, and Ca-supplemented...

  12. Role of bark and wood destroying insect pests in drying off of spruce and pines in planting weakened by smoke

    Energy Technology Data Exchange (ETDEWEB)

    Kudela, M; Wolf, R

    1963-01-01

    This paper describes a detailed study made in 1958-62, indicating the part played by smoke and the various groups and individual species of insects, in the mortality in middle-aged and mature Pine and Spruce stands.

  13. Connection between the decline of spruce and occurrence of animal pests, especially nematodes

    Energy Technology Data Exchange (ETDEWEB)

    Timans, U.

    1986-12-01

    In various regions of Bavaria, affected by the decline of spruce, attack by insects and especially nematodes was examined on diseased and healthy spruces. A connection between harmful forest insects and the decline of spruce did not become evident, neither over wide areas nor by examination of single trees. Attack by nematodes was examined in soil and wood samples and also in fine feeder roots of diseased and healthy trees. Plant-parasitic nematodes were not found in the wood and in feeder roots. Although root-parasitic nematodes were present in soil samples, their density was too little to account for a direct damage to spruce. They occurred likewise in samples from healthy and diseased trees. Plant-parasitic nematodes can thus be excluded as a possible causal agent for the decline of spruce.

  14. Long-term litter input manipulation effects on production and properties of dissolved organic matter in the forest floor of a Norway spruce stand.

    NARCIS (Netherlands)

    Klotzbücher, T.; Kaiser, K.; Stepper, C.; van Loon, E.; Gerstberger, P.; Kalbitz, K.

    2012-01-01

    Background and aims Environmental factors such as climate and atmospheric CO2 control inputs of plant-derived matter into soils, which then determines properties and decomposition of soil organic matter. We studied how dissolved organic matter (DOM) in forest floors responded to six years of litter

  15. A dynamic organic soil biogeochemical model for simulating the effects of wildfire on soil environmental conditions and carbon dynamics of black spruce forests

    Science.gov (United States)

    Shuhua Yi; A. David McGuire; Eric Kasischke; Jennifer Harden; Kristen Manies; Michelle Mack; Merritt. Turetsky

    2010-01-01

    Ecosystem models have not comprehensively considered how interactions among fire disturbance, soil environmental conditions, and biogeochemical processes affect ecosystem dynamics in boreal forest ecosystems. In this study, we implemented a dynamic organic soil structure in the Terrestrial Ecosystem Model (DOS-TEM) to investigate the effects of fire on soil temperature...

  16. Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

    Science.gov (United States)

    Johnny L. Boggs; Steven G. McNulty; Linda H. Pardo

    2007-01-01

    We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999...

  17. Pelletizing properties of torrefied spruce

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

    2011-01-01

    analysis revealed a cohesive failure mechanism due to strong inter-particle bonding in spruce pellets as a resulting from a plastic flow of the amorphous wood polymers, forming solid polymer bridges between adjacent particles. Fracture surfaces of pellets made from torrefied spruce possessed gaps and voids...

  18. Simulation of the Effect of Intensive Forest Management on Forest Production in Sweden

    Directory of Open Access Journals (Sweden)

    Ola Rosvall

    2011-03-01

    Full Text Available The effects of intensifying the management of 15% of the Swedish forest land on potential future forest production over a 100-year period were investigated in a simulation study. The intensive management treatments, which were introduced over a period of 50 years, were: intensive fertilization of Norway spruce (IntFert; bulking-up Norway spruce elite populations using somatic embryogenesis (SE-seedlings; planting of lodgepole pine, hybrid larch, and Sitka spruce (Contorta, Larch, and Sitka; fertilization with wood ash on peatlands (Wood ash; and conventional fertilization in mature forests (ConFert. Potential sites for applying intensive forest management (IFM to sites with low nature conservation values were determined with a nature conservation score (NCS. Four different scenarios were simulated: “Base scenario”, which aimed at reducing the negative impact on nature conservation values, “Fast implementation”, “No IntFert” (IntFert was not used, and “Large Forest Companies”, where the majority of plots were selected on company land. Total yields during the 100-year simulation period were about 85–92% higher for the intensive forest management scenarios than for the reference scenario (business as usual. In the “No IntFert” scenario total production was 1.8% lower and in the “Large Forest Companies” scenario total production was 4.8% lower than in the “Base scenario”. “Fast implementation” of IFM increased yield by 15% compared to the “Base scenario”. Norway spruce SE-seedlings and IntFert gave the highest yields, measured as total production during the 100-year simulation period, but relative to the yields in the reference scenario, the highest increases in yield were for Contorta. The “Base scenario” and “No IntFert” gave the highest yields for plots with the lowest NCS, but plots with higher NCS had to be used in the “Fast implementation” and “Large Forest Companies” scenarios. More than

  19. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

    Directory of Open Access Journals (Sweden)

    Anne C S McIntosh

    Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

  20. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

    Science.gov (United States)

    McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  1. Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests

    Science.gov (United States)

    McIntosh, Anne C. S.; Macdonald, S. Ellen; Quideau, Sylvie A.

    2016-01-01

    Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

  2. Soil type affects migration pattern of airborne Pb and Cd under a spruce-beech forest of the UN-ECE integrated monitoring site Zoebelboden, Austria

    Energy Technology Data Exchange (ETDEWEB)

    Kobler, Johannes, E-mail: johannes.kobler@umweltbundesamt.a [Umweltbundesamt, Spittelauer Laende 5, 1090 Vienna (Austria); Fitz, Walter J.; Dirnboeck, Thomas; Mirtl, Michael [Umweltbundesamt, Spittelauer Laende 5, 1090 Vienna (Austria)

    2010-03-15

    Anthropogenic trace element emissions have declined. However, top soils all over the world remain enriched in trace elements. We investigated Pb and Cd migration in forest soils of a remote monitoring site in the Austrian limestone Alps between 1992 and 2004. Large spatial variability masked temporal changes in the mineral soil of Lithic Leptosols (Skeltic), whereas a significant reduction of Pb concentrations in their forest floors occurred. Reductions of concentrations in the less heterogeneous Cambisols (Chromic) were significant. In contrast, virtually no migration of Pb and Cd were found in Stagnosols due to their impeded drainage. Very low element concentrations (<1 mug l{sup -1}) in field-collected soil solutions using tension lysimeters (0.2 mum nylon filters) imply that migration largely occurred by preferential flow as particulate-bound species during intensive rainfall events. Our results indicate that the extent of Pb and Cd migration in soils is largely influenced by soil type. - Comparison between soil solid phase and soil solution concentrations imply that trace element migration largely occurred by preferential flow as particulate-bound species.

  3. Influence of Time since Fire and Micro-Habitat Availability on Terricolous Lichen Communities in Black Spruce (Picea mariana Boreal Forests

    Directory of Open Access Journals (Sweden)

    Saliha Zouaoui

    2014-11-01

    Full Text Available Terricolous lichens are an important component of boreal forest ecosystems, both in terms of function and diversity. In this study, we examined the relative contribution of microhabitat characteristics and time elapsed since the last fire in shaping terricolous lichen assemblages in boreal forests that are frequently affected by severe stand-replacing fires. We sampled 12 stands distributed across five age classes (from 43 to >200 years. In each stand, species cover (% of all terricolous lichen species and species richness were evaluated within 30 microplots of 1 m2. Our results show that time elapsed since the last fire was the factor that contributed the most to explaining terricolous lichen abundance and species composition, and that lichen cover showed a quadratic relationship with stand age. Habitat variables such as soil characteristics were also important in explaining lichen richness. These results suggest that the presence of suitable substrates is not sufficient for the conservation of late-successional terricolous lichen communities in this ecosystem, and that they also need relatively long periods of times for species dispersal and establishment.

  4. Red spruce stand dynamics, simulations, and restoration opportunities in the central Appalachians

    Science.gov (United States)

    James S. Rentch; Thomas M. Schuler; W. Mark Ford; Gergory J. Nowacki

    2007-01-01

    Red spruce (Picea rubens)-dominated forests occupied as much as 600,000 ha in West Virginia prior to exploitive logging era of the late nineteenth and early twentieth centuries. Subsequently, much of this forest type was converted to northern hardwoods. As an important habitat type for a number of rare or sensitive species, only about 12,000 ha of...

  5. Climate driven changes in Engelmann spruce stands at timberline in the La Sal Mountains

    Science.gov (United States)

    James F. Fowler; Steven Overby; Barb Smith

    2012-01-01

    Due to global warming spruce-fir forest and associated vegetation may experience elevational displacement and altered species composition at the timberline-treeline ecotone. These forests and their component species are predicted to migrate upslope and thus landscape features such as timberline and treeline may move upslope as well. Prior to this study, baseline data...

  6. Relationships between Plant Diversity and the Abundance and α-Diversity of Predatory Ground Beetles (Coleoptera: Carabidae) in a Mature Asian Temperate Forest Ecosystem

    Science.gov (United States)

    Zou, Yi; Sang, Weiguo; Bai, Fan; Axmacher, Jan Christoph

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems. PMID:24376582

  7. Relationships between plant diversity and the abundance and α-diversity of predatory ground beetles (Coleoptera: Carabidae) in a mature Asian temperate forest ecosystem.

    Science.gov (United States)

    Zou, Yi; Sang, Weiguo; Bai, Fan; Axmacher, Jan Christoph

    2013-01-01

    A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae) as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems.

  8. Relationships between plant diversity and the abundance and α-diversity of predatory ground beetles (Coleoptera: Carabidae in a mature Asian temperate forest ecosystem.

    Directory of Open Access Journals (Sweden)

    Yi Zou

    Full Text Available A positive relationship between plant diversity and both abundance and diversity of predatory arthropods is postulated by the Enemies Hypothesis, a central ecological top-down control hypothesis. It has been supported by experimental studies and investigations of agricultural and grassland ecosystems, while evidence from more complex mature forest ecosystems is limited. Our study was conducted on Changbai Mountain in one of the last remaining large pristine temperate forest environments in China. We used predatory ground beetles (Coleoptera: Carabidae as target taxon to establish the relationship between phytodiversity and their activity abundance and diversity. Results showed that elevation was the only variable included in both models predicting carabid activity abundance and α-diversity. Shrub diversity was negatively and herb diversity positively correlated with beetle abundance, while shrub diversity was positively correlated with beetle α-diversity. Within the different forest types, a negative relationship between plant diversity and carabid activity abundance was observed, which stands in direct contrast to the Enemies Hypothesis. Furthermore, plant species density did not predict carabid α-diversity. In addition, the density of herbs, which is commonly believed to influence carabid movement, had little impact on the beetle activity abundance recorded on Changbai Mountain. Our study indicates that in a relatively large and heterogeneous mature forest area, relationships between plant and carabid diversity are driven by variations in environmental factors linked with altitudinal change. In addition, traditional top-down control theories that are suitable in explaining diversity patterns in ecosystems of low diversity appear to play a much less pronounced role in highly complex forest ecosystems.

  9. Quantifying sources of variation in the frequency of fungi associated with spruce beetles: implications for hypothesis testing and sampling methodology in bark beetle-symbiont relationships.

    Science.gov (United States)

    Brian H. Aukema; Richard A. Werner; Kirsten E. Haberkern; Barbara L. Illman; Murray K. Clayton; Kenneth F. Raffa

    2005-01-01

    The spruce beetle, Dendroctonus rufipennis (Kirby), causes landscape level mortality to mature spruce (Picea spp.) throughout western and northern North America. As with other bark beetles, this beetle is associated with a variety of fungi, whose ecological functions are largely unknown. It has been proposed that the relative...

  10. Does the orientation of Norway spruce (Picea abies /L./ Karst.) branches within sunlit crown part influence the heterogeneity of biochemical, structural and spectral characteristics of needles?

    NARCIS (Netherlands)

    Lhotáková, Z.; Albrechtová, J.; Malenovsky, Z.; Rock, B.N.; Polák, T.; Cudlín, P.

    2007-01-01

    The goal of this study was to determine if selected biochemical, structural and spectral properties of Norway spruce needles are influenced by the azimuth orientation of the branch. Three youngest needle age classes from 20 mature (100 years old or older) Norway spruce trees were sampled from upper

  11. Studying sulfur functional groups in Norway spruce year rings using S L-edge total electron yield spectroscopy

    International Nuclear Information System (INIS)

    Struis, Rudolf P.W.J.; Ludwig, Christian; Barrelet, Timothee; Kraehenbuehl, Urs; Rennenberg, Heinz

    2008-01-01

    Profiles of the major sulfur functional groups in mature Norway spruce wood tissue have been established for the first time. The big challenge was the development of a method suitable for sulfur speciation in samples with very low sulfur content (< 100 ppm). This became possible by synchrotron X-ray absorption spectroscopy at the sulfur L-edge in total electron yield (TEY) detection mode with thin gold-coated wood slices. Functional groups were identified using sulfur compound spectra as fingerprints. Latewood of single year rings revealed metabolic plausible sulfur forms, particularly inorganic sulfide, organic disulfide, methylthiol, and highly oxidized sulfur. Form-specific profiles with Norway spruces from three different Swiss forest sites revealed high, but hitherto little-noticed, sulfur intensities attributable to natural heartwood formation and a common, but physiologically unexpected maximum around year ring 1986 with trees from the industrialized Swiss Plateau. It is hypothesized whether it may have resulted from the huge reduction in sulfur emissions after 1980 due to Swiss policy. Comparison with total S content profiles from optical emission spectroscopy underlined the more accurate and temporally better resolved TEY data with single wood year rings and it opened novel insights into the wood cell chemistry

  12. Influence of fire frequency on carbon consumption in Alaskan blackspruce forests

    Science.gov (United States)

    Hoy, E.; Kasischke, E. S.

    2014-12-01

    Increasing temperatures and drier conditions within the boreal forests of Alaska have resulted in increases in burned area and fire frequency, which alter carbon storage and emissions. In particular, analyses of satellite remote sensing data showed that >20% of the area impacted by fires in interior Alaska occurred in areas that had previously burned since 1950 (e.g., short to intermediate interval fires). Field studies showed that in immature black spruce forests ~ 35 to 55 years old organic layers experienced deep burning regardless of topographic position or seasonality of burning, factors that control depth of burning in mature black spruce forests. Here, refinements were made to a carbon consumption model to account for variations in fuel loads and fraction of carbon consumed associated with fire frequency based on quantifying burned area in recently burned sites using satellite imagery. An immature black spruce (Picea mariana) fuel type (including stands of ~0-50 years) was developed which contains new ground-layer carbon consumption values in order to more accurately account for differences between various age classes of black spruce forest. Both versions of the model were used to assess carbon consumption during 100 fire events (over 4.4 x 10^6 ha of burned area) from two recent ultra-large fire years (2004 and 2005). Using the improved model to better attribute fuel type and consumption resulted in higher ground-layer carbon consumption (4.9% in 2004 and 6.8% in 2005) than previously estimated. These adjustments in ground-layer burning resulted in total carbon consumption within 2004 and 2005 of 63.5 and 42.0 Tg of carbon, respectively. Results from this research could be incorporated into larger scale modeling efforts to better assess changes in the climate-fire-vegetation dynamics in interior Alaskan boreal forests, and to understand the impacts of these changes on carbon consumption and emissions.

  13. Evaluating the impact of abrupt changes in forest policy and management practices on landscape dynamics: analysis of a Landsat image time series in the Atlantic Northern Forest.

    Science.gov (United States)

    Legaard, Kasey R; Sader, Steven A; Simons-Legaard, Erin M

    2015-01-01

    Sustainable forest management is based on functional relationships between management actions, landscape conditions, and forest values. Changes in management practices make it fundamentally more difficult to study these relationships because the impacts of current practices are difficult to disentangle from the persistent influences of past practices. Within the Atlantic Northern Forest of Maine, U.S.A., forest policy and management practices changed abruptly in the early 1990s. During the 1970s-1980s, a severe insect outbreak stimulated salvage clearcutting of large contiguous tracts of spruce-fir forest. Following clearcut regulation in 1991, management practices shifted abruptly to near complete dependence on partial harvesting. Using a time series of Landsat satellite imagery (1973-2010) we assessed cumulative landscape change caused by these very different management regimes. We modeled predominant temporal patterns of harvesting and segmented a large study area into groups of landscape units with similar harvest histories. Time series of landscape composition and configuration metrics averaged within groups revealed differences in landscape dynamics caused by differences in management history. In some groups (24% of landscape units), salvage caused rapid loss and subdivision of intact mature forest. Persistent landscape change was created by large salvage clearcuts (often averaging > 100 ha) and conversion of spruce-fir to deciduous and mixed forest. In groups that were little affected by salvage (56% of landscape units), contemporary partial harvesting caused loss and subdivision of intact mature forest at even greater rates. Patch shape complexity and edge density reached high levels even where cumulative harvest area was relatively low. Contemporary practices introduced more numerous and much smaller patches of stand-replacing disturbance (typically averaging forest ecology.

  14. Diversity patterns of ground beetles and understory vegetation in mature, secondary, and plantation forest regions of temperate northern China

    NARCIS (Netherlands)

    Zou, Yi; Sang, Weiguo; Wang, Shunzhong; Warren-Thomas, Eleanor; Liu, Yunhui; Yu, Zhenrong; Wang, Changliu; Axmacher, Jan Christoph

    2015-01-01

    Plantation and secondary forests form increasingly important components of the global forest cover, but our current knowledge about their potential contribution to biodiversity conservation is limited. We surveyed understory plant and carabid species assemblages at three distinct regions in

  15. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  16. Warming and neighbor removal affect white spruce seedling growth differently above and below treeline.

    Science.gov (United States)

    Okano, Kyoko; Bret-Harte, M Syndonia

    2015-01-01

    Climate change is expected to be pronounced towards higher latitudes and altitudes. Warming triggers treeline and vegetation shifts, which may aggravate interspecific competition and affect biodiversity. This research tested the effects of a warming climate, habitat type, and neighboring plant competition on the establishment and growth of white spruce (Picea glauca (Moench) Voss) seedlings in a subarctic mountain region. P. glauca seedlings were planted in June 2010 under 4 different treatments (high/control temperatures, with/without competition) in 3 habitats (alpine ridge above treeline/tundra near treeline /forest below treeline habitats). After two growing seasons in 2011, growth, photosynthesis and foliar C and N data were obtained from a total of 156, one-and-a-half year old seedlings that had survived. Elevated temperatures increased growth and photosynthetic rates above and near treeline, but decreased them below treeline. Competition was increased by elevated temperatures in all habitat types. Our results suggest that increasing temperatures will have positive effects on the growth of P. glauca seedlings at the locations where P. glauca is expected to expand its habitat, but increasing temperatures may have negative effects on seedlings growing in mature forests. Due to interspecific competition, possibly belowground competition, the upslope expansion of treelines may not be as fast in the future as it was the last fifty years.

  17. The Validation of the Mixedwood Growth Model (MGM for Use in Forest Management Decision Making

    Directory of Open Access Journals (Sweden)

    Mike Bokalo

    2013-01-01

    Full Text Available We evaluated the Mixedwood Growth Model (MGM at a whole model scale for pure and mixed species stands of aspen and white spruce in the western boreal forest. MGM is an individual tree-based, distance-independent growth model, designed to evaluate growth and yield implications relating to the management of white spruce, black spruce, aspen, lodgepole pine, and mixedwood stands in Alberta, British Columbia, Saskatchewan, and Manitoba. Our validation compared stand-level model predictions against re-measured data (volume, basal area, diameter at breast height (DBH, average and top height and density from permanent sample plots using combined analysis of residual plots, bias statistics, efficiency and an innovative application of the equivalence test. For state variables, the model effectively simulated juvenile and mature stages of stand development for both pure and mixed species stands of aspen and white spruce in Alberta. MGM overestimates increment in older stands likely due to age-related pathology and weather-related stand damage. We identified underestimates of deciduous density and volume in Saskatchewan. MGM performs well for increment in postharvest stands less than 30 years of age. These results illustrate the comprehensive application of validation metrics to evaluate a complex model, and provide support for the use of MGM in management planning.

  18. Induced terpene accumulation in Norway spruce inhibits bark beetle colonization in a dose-dependent manner.

    Directory of Open Access Journals (Sweden)

    Tao Zhao

    Full Text Available Tree-killing bark beetles (Coleoptera, Scolytinae are among the most economically and ecologically important forest pests in the northern hemisphere. Induction of terpenoid-based oleoresin has long been considered important in conifer defense against bark beetles, but it has been difficult to demonstrate a direct correlation between terpene levels and resistance to bark beetle colonization.To test for inhibitory effects of induced terpenes on colonization by the spruce bark beetle Ips typographus (L. we inoculated 20 mature Norway spruce Picea abies (L. Karsten trees with a virulent fungus associated with the beetle, Ceratocystis polonica (Siem. C. Moreau, and investigated induced terpene levels and beetle colonization in the bark.Fungal inoculation induced very strong and highly variable terpene accumulation 35 days after inoculation. Trees with high induced terpene levels (n = 7 had only 4.9% as many beetle attacks (5.1 vs. 103.5 attacks m(-2 and 2.6% as much gallery length (0.029 m m(-2 vs. 1.11 m m(-2 as trees with low terpene levels (n = 6. There was a highly significant rank correlation between terpene levels at day 35 and beetle colonization in individual trees. The relationship between induced terpene levels and beetle colonization was not linear but thresholded: above a low threshold concentration of ∼100 mg terpene g(-1 dry phloem trees suffered only moderate beetle colonization, and above a high threshold of ∼200 mg terpene g(-1 dry phloem trees were virtually unattacked.This is the first study demonstrating a dose-dependent relationship between induced terpenes and tree resistance to bark beetle colonization under field conditions, indicating that terpene induction may be instrumental in tree resistance. This knowledge could be useful for developing management strategies that decrease the impact of tree-killing bark beetles.

  19. Maine's forests 2008

    Science.gov (United States)

    George L. McCaskill; William H. McWilliams; Charles J. Barnett; Brett J. Butler; Mark A. Hatfield; Cassandra M. Kurtz; Randall S. Morin; W. Keith Moser; Charles H. Perry; Christopher W. Woodall

    2011-01-01

    The second annual inventory of Maine's forests was completed in 2008 after more than 3,160 forested plots were measured. Forest land occupies almost 17.7 million acres, which represents 82 percent of the total land area of Maine. The dominant forest-type groups are maple/beech/yellow birch, spruce/fir, white/red/jack pine, and aspen/white birch. Statewide volume...

  20. Preliminary results of a study on the soil mesofauna in disturbed spruce forest stands near Čertovo and Plešné Lakes in the Bohemian Forest (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Čuchta, Peter; Starý, Josef

    2015-01-01

    Roč. 79, č. 3 (2015), s. 161-167 ISSN 1211-376X R&D Projects: GA ČR GAP504/12/1218 Institutional support: RVO:60077344 Keywords : windthrow * bark beetle * soil arthropod s * Bohemian Forest Subject RIV: EH - Ecology, Behaviour

  1. Development of soil water regime under spruce stands

    Directory of Open Access Journals (Sweden)

    Tužinský Ladislav

    2017-06-01

    Full Text Available The aim of this paper is to analyse the water regime of soils under spruce ecosystems in relation to long-lasting humid and drought periods in the growing seasons 1991-2013. The dominant interval humidity in observing growing seasons is semiuvidic interval with soil moisture between hydro-limits maximal capillary capacity (MCC and point of diminished availability (PDA. Gravitationally seepage concentrated from accumulated winter season, water from melting snow and existing atmospheric precipitation occurs in the soil only at the beginning of the growing season. The supplies of soil water are significantly decreasing in the warm climate and precipitant deficient days. The greatest danger from drought threatens Norway spruce during the summer months and it depends on the duration of dry days, water supply at the beginning of the dry days, air temperature and the intensity of evapotranspiration. In the surface layers of the soil, with the maximum occurrence of active roots, the water in semiarid interval area between hydro-limits PDA and wilting point (WP decreases during the summer months. In the culminating phase occurs the drying to moisture state with capillary stationary and the insufficient supply of available water for the plants. Physiological weakening of Norway spruce caused by set of outlay components of the water balance is partially reduced by delivering of water by capillary action from deeper horizons. In extremely dry periods, soil moisture is decreasing also throughout the soil profile (0-100 cm into the bottom third of the variation margin hydro-limits MCC-PDA in the category of capillary less moving and for plants of low supply of usable water (60-90 mm. The issue of deteriorated health state of spruce ecosystems is considered to be actual. Changes and developments of hydropedological conditions which interfere the mountain forests represent the increasing danger of the drought for the spruce.

  2. Spruce Lake Dam reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, G. [SGE Acres Ltd., Fredericton, NB (Canada); Barnard, J. [SGE Acres Ltd., St. John' s, NF (Canada); Vriezen, C. [City of Saint John, NF (Canada); Stephenson, M. [Jacques Whitford Environment Ltd., Fredericton, NB (Canada)

    2004-09-01

    Spruce Lake Dam was constructed in 1898 as part of the water supply system for Saint John, New Brunswick. The original dam was a 6 meter high, 140 meter long concrete gravity dam with an intake structure at its mid point and an overflow spillway at the left abutment. A rehabilitation project was launched in 2001 to bring the deteriorated dam into conformance with the dam safety guidelines of the Canadian Dam Association. The project criteria included minimal disruption to normal operation of water supply facilities and no negative effect on water quality. The project involved installation of a new low level outlet, removal of a gate house and water intake pipes, replacement of an access road culvert in the spillway channel, and raising the earth dam section by 1.8 meters to allow for increased water storage. The new raised section has an impervious core. The project also involved site and geotechnical investigations as well as hydrotechnical and environmental studies. This presentation described the final design of the remedial work and the environmental permitting procedures. Raising the operating level of the system proved successful as demonstrated by the fewer number of pumping days required after dam rehabilitation. The dam safety assessment under the Canadian Environmental Assessment Act began in April 2001, and the rehabilitation was completed by the end of 2002. 1 tab., 8 figs.

  3. Retrospective determination of 137Cs specific activity distribution in spruce bark and bark aggregated transfer factor in forests on the scale of the Czech Republic ten years after the Chernobyl accident.

    Science.gov (United States)

    Suchara, I; Rulík, P; Hůlka, J; Pilátová, H

    2011-04-15

    The (137)Cs specific activities (mean 32Bq kg(-1)) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The (137)Cs specific activities in spruce bark correlated significantly with the (137)Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the (137)Cs specific activities in bark and of the (137)Cs deposition levels yielded bark aggregated transfer factor T(ag) about 10.5×10(-3)m(-2)kg(-1). Taking into account the residual specific activities of (137)Cs in bark 20Bq kg(-1) and the available pre-Chernobyl data on the (137)Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T*(ag)=3.3×10(-3)m(-2)kg(-1) and T**(ag)=4.0×10(-3)m(-2)kg(-1), respectively. The aggregated transfer factors T*(ag) for (137)Cs and spruce bark did not differ significantly in areas unequally affected by the (137)Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark T(ag) values published from the extensively affected areas near Chernobyl. The magnitude of the (137)Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of (137)Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining (137)Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because the sums of this precipitation increased with elevation (covariable). Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Retrospective determination of {sup 137}Cs specific activity distribution in spruce bark and bark aggregated transfer factor in forests on the scale of the Czech Republic ten years after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Suchara, I., E-mail: suchara@vukoz.cz [Silva Tarouca Research Institute for Landscape and Ornamental Gardening, Kvetnove namesti 391, CZ 252 43 Pruhonice (Czech Republic); Rulik, P., E-mail: petr.rulik@suro.cz [National Radiation Protection Institute, Bartoskova 28, CZ 140 00 Prague 4 (Czech Republic); Hulka, J., E-mail: jiri.hulka@suro.cz [National Radiation Protection Institute, Bartoskova 28, CZ 140 00 Prague 4 (Czech Republic); Pilatova, H., E-mail: helena.pilatova@suro.cz [National Radiation Protection Institute, Bartoskova 28, CZ 140 00 Prague 4 (Czech Republic)

    2011-04-15

    The {sup 137}Cs specific activities (mean 32 Bq kg{sup -1}) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The {sup 137}Cs specific activities in spruce bark correlated significantly with the {sup 137}Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the {sup 137}Cs specific activities in bark and of the {sup 137}Cs deposition levels yielded bark aggregated transfer factor T{sub ag} about 10.5 x 10{sup -3} m{sup -2} kg{sup -1}. Taking into account the residual specific activities of {sup 137}Cs in bark 20 Bq kg{sup -1} and the available pre-Chernobyl data on the {sup 137}Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T*{sub ag} = 3.3 x 10{sup -3} m{sup -2} kg{sup -1} and T**{sub ag} = 4.0 x 10{sup -3} m{sup -2} kg{sup -1}, respectively. The aggregated transfer factors T*{sub ag} for {sup 137}Cs and spruce bark did not differ significantly in areas unequally affected by the {sup 137}Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark T{sub ag} values published from the extensively affected areas near Chernobyl. The magnitude of the {sup 137}Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of {sup 137}Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining {sup 137}Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because

  5. Stem volume losses in grand firs topkilled by western spruce budworm in Idaho

    Science.gov (United States)

    George T. Ferrell; Robert F. Scharpf

    1982-01-01

    Mature grand firs (Abies grandis [Dougl. ex D. Don] Lindl.) were sampled in two stands, one cutover and one virgin, in the Little Salmon River drainage in west-central Idaho, to estimate stem volume losses associated with topkilling. Damage to the stands resulted from three outbreaks of western spruce budworm (Choristoneura occidentalis...

  6. Ammonium assmilation in spruce ectomycorrhizas

    International Nuclear Information System (INIS)

    Chalot, M.; Brun, A.; Botton, B.; Stewart, G.

    1990-01-01

    Assimilation of labelled NH 4 + into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH 4 + feeding, Gln, Glu and Ala became the most abundant amino acids. Gln was also the most highly labelled amino acid during the experiment, followed by Glu and Ala. This result indicates that Gln synthesis is an important ammonium utilization reaction in spruce mycorrhizas. Addition of MSX to NH 4 + fed mycorrhizas caused an inhibition of Gln accumulation with a corresponding increase in Glu, Ala and Asn levels. The supply of MSX induced a sharp diminution of 15 N enrichment in both amino and amido groups of glutamine. In contrast, the 15 N incorporation into Glu and derivatives (Ala and Asp) remained very high. This study demonstrates that the fungal glutamate dehydrogenase is quite operative in spruce ectomycorrhizas since it is able to sustain ammonium assimilation when glutamine synthetase is inhibited

  7. Field test of foliar-spray herbicides to control mountain laurel in mature mixed-oak forests in western Maryland

    Science.gov (United States)

    Gary W. Miller; Patrick H. Brose; Jeffrey D. Kochenderfer; James N. Kochenderfer; Kurt W. Gottschalk; John R. Denning

    2016-01-01

    Successful oak (Quercus spp.) regeneration requires the presence of competitive sources of oak reproduction before parent oaks are harvested. Mountain laurel (Kalmia latifolia) in the understory of many Appalachian forests prevents new oak seedlings from receiving adequate sunlight to survive and grow into competitive size classes. This study examined the efficacy of...

  8. Species and structural diversity affect growth of oak, but not pine, in uneven-aged mature forests

    NARCIS (Netherlands)

    Vanhellemont, Margot; Bijlsma, Rienk Jan; Keersmaeker, De Luc; Vandekerkhove, Kris; Verheyen, Kris

    2018-01-01

    The effects of mixing tree species on tree growth and stand production have been abundantly studied, mostly looking at tree species diversity effects while controlling for stand density and structure. Regarding the shift towards managing forests as complex adaptive systems, we also need insight into

  9. From a tree to a stand in Finnish boreal forests: biomass estimation and comparison of methods

    OpenAIRE

    Liu, Chunjiang

    2009-01-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61º50' N, 24º22' E). In particular, a comparison of the results of different estimati...

  10. Factors affecting spruce establishment and recruitment near western treeline, Alaska

    Science.gov (United States)

    Miller, A. E.; Sherriff, R.; Wilson, T. L.

    2015-12-01

    Regional warming and increases in tree growth are contributing to increased productivity near the western forest margin in Alaska. The effects of warming on seedling recruitment has received little attention, in spite of forecasted forest expansion near western treeline. Here, we used stand structure and environmental data from white spruce (Picea glauca) stands (n = 95) sampled across a longitudinal gradient to explore factors influencing white spruce growth, establishment and recruitment in southwest Alaska. Using tree-ring chronologies developed from a subset of the plots (n = 30), we estimated establishment dates and basal area increment (BAI) for trees of all age classes across a range of site conditions. We used GLMs (generalized linear models) to explore the relationship between tree growth and temperature in undisturbed, low elevation sites along the gradient, using BAI averaged over the years 1975-2000. In addition, we examined the relationship between growing degree days (GDD) and seedling establishment over the previous three decades. We used total counts of live seedlings, saplings and live and dead trees, representing four cohorts, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance of the different size classes. We hypothesized that the relationship between abundance and longitude would vary by size class, and that this relationship would be mediated by growing season temperature. We found that mean BAI for trees in undisturbed, low elevation sites increased with July maximum temperature, and that the slope of the relationship with temperature changed with longitude (interaction significant with 90% confidence). White spruce establishment was positively associated with longer summers and/or greater heat accumulation, as inferred from GDD. Seedling, sapling and tree abundance were also positively correlated with temperature across the study area. The response to longitude was mixed, with smaller size classes

  11. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison

    2009-01-01

    Calcium cycling plays a key role in the health and productivity of red spruce forests in the northeastern US. A portion of the flowpath of calcium within forests includes translocation as Ca2+ in sapwood and accumulation as crystals of calcium oxalate in foliage. Concentrations of Ca in these tree tissues have been used as markers of...

  12. CLIMATE CHANGE AND ORIENTAL SPRUCE (PICEA ORIENTALIS ECOSYSTEMS IN EASTERN BLACKSEA REGION OF TURKEY

    Directory of Open Access Journals (Sweden)

    Aydın Tüfekçioğlu

    2008-04-01

    Full Text Available Climate change has been getting more attention from scientific community recently. Eastern Black Sea Region of Turkey will get significant influences from the climate change according to regional climate model (RegCM3. Oriental spruce (Picea orientalis L. is an important tree species of Turkey and it only grows in the Eastern Black Sea Region of Turkey. With the increase in global warming, spruce forests started to have serious bark beetle problems. More than 200 000 trees died in the region recently due to bark beetle attack. We used existing literature related to oriental spruce and future climate of the region and field observations done in the different times to assess current status of the spruce stands. Future climate of the region has been predicted using RegCM3 regional climate model. Climate change could significantly influence distribution, diversity, structure and stability of the oriental spruce ecosystems. According to RegCM3 regional climate model, the temperatures will increase 2-4 °C in the region in the next century. Future climate scenarios predict 200-300 mm increases in precipitation in the eastern part of the region while the western part won't have any increase in precipitation in the next century. Temperature increases in the western part of the region can cause more stress on spruce trees and would probably increase bark beetle attacks. Also, fire could become an important threat in the western part of the region. It is possible to observe 400-800 m upward shift in the spruce belt in the western part. Treeline of spruce stands would probably move upward both in western and eastern part of the North-eastern Blacksea Region.

  13. Biosynthesis of the major tetrahydroxystilbenes in spruce, astringin and isorhapontin, proceeds via resveratrol and is enhanced by fungal infection.

    Science.gov (United States)

    Hammerbacher, Almuth; Ralph, Steven G; Bohlmann, Joerg; Fenning, Trevor M; Gershenzon, Jonathan; Schmidt, Axel

    2011-10-01

    Stilbenes are dibenzyl polyphenolic compounds produced in several unrelated plant families that appear to protect against various biotic and abiotic stresses. Stilbene biosynthesis has been well described in economically important plants, such as grape (Vitis vinifera), peanut (Arachis hypogaea), and pine (Pinus species). However, very little is known about the biosynthesis and ecological role of stilbenes in spruce (Picea), an important gymnosperm tree genus in temperate and boreal forests. To investigate the biosynthesis of stilbenes in spruce, we identified two similar stilbene synthase (STS) genes in Norway spruce (Picea abies), PaSTS1 and PaSTS2, which had orthologs with high sequence identity in sitka (Picea sitchensis) and white (Picea glauca) spruce. Despite the conservation of STS sequences in these three spruce species, they differed substantially from angiosperm STSs. Several types of in vitro and in vivo assays revealed that the P. abies STSs catalyze the condensation of p-coumaroyl-coenzyme A and three molecules of malonyl-coenzyme A to yield the trihydroxystilbene resveratrol but do not directly form the dominant spruce stilbenes, which are tetrahydroxylated. However, in transgenic Norway spruce overexpressing PaSTS1, significantly higher amounts of the tetrahydroxystilbene glycosides, astringin and isorhapontin, were produced. This result suggests that the first step of stilbene biosynthesis in spruce is the formation of resveratrol, which is further modified by hydroxylation, O-methylation, and O-glucosylation to yield astringin and isorhapontin. Inoculating spruce with fungal mycelium increased STS transcript abundance and tetrahydroxystilbene glycoside production. Extracts from STS-overexpressing lines significantly inhibited fungal growth in vitro compared with extracts from control lines, suggesting that spruce stilbenes have a role in antifungal defense.

  14. Efflux of CO2 from soil in Norway Spruce stands of different ages: a case study

    Czech Academy of Sciences Publication Activity Database

    Dařenová, Eva; Fabiánek, Tomáš; Pavelka, Marian

    2016-01-01

    Roč. 6, č. 2 (2016), s. 98-102 ISSN 1805-0174 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : spruce forest * Picea abies * soil temperatures * moisture * respiration Subject RIV: EH - Ecology, Behaviour

  15. Growth comparison of northern white-cedar to balsam fir and red spruce by site class

    Science.gov (United States)

    Philip V. Hofmeyer; Laura S. Kenefic; Robert S. Seymour; John C. Brissette

    2006-01-01

    Though northern white-cedar is a common and economically important component of the Acadian Forest of Maine and adjacent Canada, there is little regional data about the growth and development of this species. Sixty sites in northern Maine were used to compare growth of cedar to that of red spruce and balsam fir along a range of site classes and light exposures. On...

  16. Phenotypic evidence suggests a possible major-gene element to weevil resistance in Sitka spruce

    Science.gov (United States)

    John N. King; René I. Alfaro; Peter Ott; Lara vanAkker

    2012-01-01

    The weevil resistance breeding program against the white pine weevil, Pissodes strobi Peck (Coleoptera: Curculionidae), particularly for Sitka spruce (Picea sitchensis (Bong.) Carr), is arguably one of the most successful pest resistance breeding programs for plantation forest species, and it has done a lot to rehabilitate...

  17. Multipartite Symbioses Among Fungi, Mites, Nematodes, and the Spruce Beetle, Dendroctonus rufipennis.

    Science.gov (United States)

    Yasmin Cardoza; John Moser; Kier Klepzizg; Raffa Kenneth

    2008-01-01

    The spruce beetle, Dendroctonus rufipennis, is an eruptive forest pest of signifcant economic and ecological importance. D. rufipennis has symbiotic associations with a number of microorganisms, especially the ophiostomatoid fungus Leptographium abietinum. The nature of this interaction is only partially understood. Additionally, mite and nematode associates can...

  18. Balsam fir conservation and red spruce ecosystem restoration initiatives in the West Virginia highlands

    Science.gov (United States)

    Corey A. Bonasso; David W. Saville

    2010-01-01

    The West Virginia Highlands Conservancy has been working for more than a decade to protect, conserve, and restore the spruce-fir forests in West Virginia. Beginning in the mid 1990s an effort was initiated to conserve balsam fir in West Virginia where it reaches its southern most extent in North America. This work led to further efforts which have focused on the...

  19. Root uptake of lead by Norway spruce grown on Pb-210 spiked soils

    DEFF Research Database (Denmark)

    Hovmand, M.F.; Nielsen, Sven Poul; Johnsen, I.

    2009-01-01

    The root uptake of lead (Pb) by trees and the transfer of Pb by leaf litter deposition to the forest floor were investigated through a pot experiment with Norway spruce. Natural Pb and radio isotopic lead (210Pb) were determined in needles and twigs and in the pot soil spiked with 210Pb...

  20. Effects of a western spruce budworm outbreak on private lands in eastern Oregon, 1980-1994.

    Science.gov (United States)

    David L. Azuma; David L. Overhulser

    2008-01-01

    Forest Inventory and Analysis data from three inventory periods were used to examine the effects of a western spruce budworm outbreak on private lands in eastern Oregon. Growth was negatively related to defoliation with differences between crown ratio and species. The mortality and salvage harvesting caused changes in stand structure on private lands. Although many...

  1. Characteristics of organic matter fractions separated by wet-sieving and differences in density from five soils of different pedogenesis under mature beech forest.

    Science.gov (United States)

    Vormstein, Svendja; Kaiser, Michael; Ludwig, Bernard

    2017-04-01

    Forest top- and subsoil account for approximately 70 % of the organic C (OC) globally stored in soil reasoning their large importance for terrestrial ecosystem services such as the mitigation of climate change. In contrast to forest topsoil, there is much less information about the decomposition and stabilization of organic matter (OM) in subsoil. Therefore, we sampled the pedogenetic horizons of five soils under mature beech forest developed on different parent material (i.e. Tertiary Sand, Loess, Basalt, Lime Stone, Red Sandstone) down to the bedrock. The bulk soil samples were characterized for texture, oxalate and dithionite soluble Fe and Al, pH, OC, microbial biomass C and basal respiration (cumulative CO2 emission after 7 and 14 days). Furthermore, we analyzed aggregate size fractions separated by wet-sieving (i.e. >1000 µm, 1000-250 µm, 250-53 µm, soil horizon specific samples. The OC of the topsoil (Ah horizon) on Lime Stone and Red Sandstone was predominately stored in the larger macro-aggregates (>1000 µm). In contrast, the major part of the topsoil OC on Basalt and Tertiary Sand was found in the smaller macro-aggregates (1000-250 µm). For the topsoil samples, we found that the basal respiration as well as the microbial biomass C were positively correlated (p ≤0.05) with the OC amounts associated with the free and occluded light fraction and with the macro-aggregates (1000-250 µm) and micro-aggregates (250-53 µm) suggesting these fractions to store the major part of the easily decomposable OM. The OC amount associated with the heavy fraction and the fraction stabilization in forest topsoil. In the subsoil (horizons below the Ah), the contribution of the OC associated with the aggregate size fractions 53 µm were positively correlated with basal respiration and the microbial biomass C. This suggests, in contrast to the topsoil, the easily decomposable OM to be distributed more homogeneously among fractions. Only the OC content of the soil mineral

  2. Functions for biomass and basic density of stem, crown and root system of Norway spruce (Picea abies (L.) Karst.) in Denmark

    DEFF Research Database (Denmark)

    Skovsgaard, Jens Peter; Bald, Caroline; Nord-Larsen, Thomas

    2011-01-01

    Models for predicting the biomass of forest trees are becoming increasingly important for assessing forest resources and carbon sequestration in forests. We developed functions for predicting the biomass and basic density of above- and below-ground parts of Norway spruce (Picea abies (L.) Karst.)...

  3. Upland Trees Contribute to Exchange of Nitrous Oxide (N2O) in Forest Ecosystems

    Science.gov (United States)

    Tian, H.; Thompson, R.; Canadell, J.; Winiwarter, W.; Machacova, K.; Maier, M.; Halmeenmäki, E.; Svobodova, K.; Lang, F.; Pihlatie, M.; Urban, O.

    2017-12-01

    The increase in atmospheric nitrous oxide (N2O) concentration contributes to the acceleration of the greenhouse effect. However, the role of trees in the N2O exchange of forest ecosystems is still an open question. While the soils of temperate and boreal forests were shown to be a natural source of N2O, trees have been so far overlooked in the forest N2O inventories. We determined N2O fluxes in common tree species of boreal and temperate forests: Scots pine (Pinus sylvestris), Norway spruce (Picea abies), downy and silver birch (Betula pubescens, B. pendula), and European beech (Fagus sylvatica). We investigated (1) whether these tree species exchange N2O with the atmosphere under natural field conditions, (2) how the tree N2O fluxes contribute to the forest N2O balance, and (3) whether these fluxes show seasonal dynamics. The studies were performed in a boreal forest (SMEAR II station, Finland; June 2014 - May 2015) and two temperate mountain forests (White Carpathians, Czech Republic; Black Forest, Germany; June and July 2015). Fluxes of N2O in mature tree stems and forest floor were measured using static chamber systems followed by chromatographic and photo-acoustic analyses of N2O concentration changes. Pine, spruce and birch trees were identified as net annual N2O sources. Spruce was found the strongest emitter (0.27 mg ha-1 h-1) amounting thus up to 2.5% of forest floor N2O emissions. All tree species showed a substantial seasonality in stem N2O flux that was related to their physiological activity and climatic variables. In contrast, stems of beech trees growing at soils consuming N2O may act as a substantial sink of N2O from the atmosphere. Consistent N2O consumption by tree stems ranging between -12.1 and -35.2 mg ha-1 h-1 and contributing by up to 3.4% to the forest floor N2O uptake is a novel finding in contrast to current studies presenting trees as N2O emitters. To understand these fluxes, N2O exchange of photoautotrophic organisms associated with

  4. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest (P-53)

    Science.gov (United States)

    Joseph E. Crouse; Margaret M. Moore; Peter Z. Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  5. Elevated CO{sub 2} in a prototype free-air CO{sub 2} enrichment facility affects photosynthetic nitrogen relations in a maturing pine forest

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth, D.S.; LaRoche, J.; Hendrey, G.R.

    1998-03-01

    A maturing loblolly pine (Pinus taeda L.) forest was exposed to elevated CO{sub 2} in the natural environment in a perturbation study conducted over three seasons using the free-air CO{sub 2} enrichment (FACE) technique. At the time measurements were begun in this study, the pine canopy was comprised entirely of foliage which had developed under elevated CO{sub 2} conditions (atmospheric CO{sub 2} {approx} 550 {micro}mol/mol{sup {minus}1}). Measurements of leaf photosynthetic responses to CO{sub 2} were taken to examine the effects of elevated CO{sub 2} on photosynthetic N nutrition in a pine canopy under elevated CO{sub 2}. Photosynthetic CO{sub 2} response curves (A-c{sub i} curves) were similar in FACE trees under elevated CO{sub 2} compared with counterpart trees in ambient plots for the first foliage cohort produced in the second season of CO{sub 2} exposure, with changes in curve form detected in the foliage cohorts subsequently produced under elevated CO{sub 2}. Differences in the functional relationship between carboxylation rate and N{sub a} suggest that for a given N{sub a} allocated among successive cohorts of foliage in the upper canopy, V{sub c max} was 17% lower in FACE versus Ambient trees. The authors also found that foliar Rubisco content per unit total protein derived from Western blot analysis was lower in late-season foliage in FACE foliage compared with ambient-grown foliage. The results illustrate a potentially important mode of physiological adjustment to growth conditions that may operate in forest canopies. Findings suggest that mature loblolly pine trees growing in the field may have the capacity for shifts in intrinsic nitrogen utilization for photosynthesis under elevated CO{sub 2} that are not dependent on changes in leaf N. Findings suggest a need for continued examination of internal feedbacks at the whole-tree and ecosystem level in forests that may influence long-term photosynthetic responses to elevated CO{sub 2}.

  6. ELEVATED CO{sub 2} IN A PROTOTYPE FREE-AIR CO{sub 2} ENRICHMENT FACILITY AFFECTS PHOTOSYNTHETIC NITROGEN RELATIONS IN A MATURING PINE FOREST

    Energy Technology Data Exchange (ETDEWEB)

    ELLSWORTH,D.S.; LA ROCHE,J.; HENDREY,G.R.

    1998-03-01

    A maturing loblolly pine (Pinus taeda L.) forest was exposed to elevated CO{sub 2} in the natural environment in a perturbation study conducted over three seasons using the free-air CO{sub 2} enrichment (FACE) technique. At the time measurements were begun in this study, the pine canopy was comprised entirely of foliage which had developed under elevated CO{sub 2} conditions (atmospheric [CO{sub 2}] {approx} 550 {micro}mol mol{sup {minus}1}). Measurements of leaf photosynthetic responses to CO{sub 2} were taken to examine the effects of elevated CO{sub 2} on photosynthetic N nutrition in a pine canopy under elevated CO{sub 2}. Photosynthetic CO{sub 2} response curves (A-c{sub i} curves) were similar in FACE trees under elevated CO{sub 2} compared with counterpart trees in ambient plots for the first foliage cohort produced in the second season of CO{sub 2} exposure, with changes in curve form detected in the foliage cohorts subsequently produced under elevated CO{sub 2}. Differences in the functional relationship between carboxylation rate and N{sub a} suggest that for a given N{sub a} allocated among successive cohorts of foliage in the upper canopy, V{sub c max} was 17% lower in FACE versus Ambient trees. The authors also found that foliar Rubisco content per unit total protein derived from Western blot analysis was lower in late-season foliage in FACE foliage compared with ambient-grown foliage. The results illustrate a potentially important mode of physiological adjustment to growth conditions that may operate in forest canopies. Their findings suggest that mature loblolly pine trees growing in the field may have the capacity for shifts in intrinsic nitrogen utilization for photosynthesis under elevated CO{sub 2} that are not dependent on changes in leaf N. While carboxylation efficiency per unit N apparently decreased under elevated CO{sub 2}, photosynthetic rates in trees at elevated CO{sub 2} concentrations {approx} 550 pmol mol{sub {minus}1} are still

  7. Growth effects after whole-tree harvest in final cut of Scots pine and Norway spruce forest. Final report; Tillvaexteffekternas storlek och uthaallighet efter skogsbraensleuttag i slutavverkning av tall och gran. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Valinger, E. [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Silviculture

    2001-12-01

    A great concern in forestry today is whether whole-tree harvesting influence site productivity and whether it is consistent with the principle of sustainable use of forest resources. To evaluate this a randomised field experiment established 24 years ago in Scots pine (Pinus sylvestris L.) in Southern Sweden was used. The field experiment was established in fall 1975 as a naturally regenerated mixed forest with Scots pine and Norway spruce (Picea abies (L.) Karst.) with a growing stock of 305 m{sup 3}/ha was clear-cut near Kosta (56 deg 52' N, 15 deg 50' E, 240 m.a.s.l.). The site was a mesic dwarf-shrub type of medium fertility, with an average precipitation of 600 mm yr-1 and the soil was an orthic podzol. Treatments were conventional stem harvest (CH), whole-tree harvest (WTH), and branch and stem harvest (BSH). Scots pine seedlings of local provenance were planted in spring 1977 at the beginning of the second growing season following the harvest. The seedlings were planted in exposed mineral soil in manually scarified patches (40 x 40 cm) at 1.7 m spacing (144 seedlings per assessment plot, i.e. 3 600 seedlings/ha). Based on calliper data, the diameter for the mean basal area per tree (db) was calculated for each plot after 24 years using the formula: db = ({sigma} b{sup 3}/{sigma} b{sup 2}), where b is basal area at breast height for each tree. Three undamaged sample trees with a diameter equal or close to the diameter of the mean basal area per tree were selected on each plot giving 36 stems that were felled for destructive measurements in 2000. Total tree height ({+-} 0.01 m) was measured on every tree felled. Stem biomass was estimated by sampling of stem discs, 2 cm thick, at stump height (1 % of tree height), breast height (1.3 m), and at every meter along the bole. Crown biomass was estimated by sampling live and dead branches on the felled trees. From every whorl of branches one living branch was sampled and all branches were counted. Stem

  8. Integrated transcriptomic and proteomic profiling of white spruce stems during the transition from active growth to dormancy.

    Science.gov (United States)

    Galindo González, Leonardo M; El Kayal, Walid; Ju, Chelsea J-T; Allen, Carmen C G; King-Jones, Susanne; Cooke, Janice E K

    2012-04-01

    In the autumn, stems of woody perennials such as forest trees undergo a transition from active growth to dormancy. We used microarray transcriptomic profiling in combination with a proteomics analysis to elucidate processes that occur during this growth-to-dormancy transition in a conifer, white spruce (Picea glauca[Moench] Voss). Several differentially expressed genes were likely associated with the developmental transition that occurs during growth cessation in the cambial zone and the concomitant completion of cell maturation in vascular tissues. Genes encoding for cell wall and membrane biosynthetic enzymes showed transcript abundance patterns consistent with completion of cell maturation, and also of cell wall and membrane modifications potentially enabling cells to withstand the harsh conditions of winter. Several differentially expressed genes were identified that encoded putative regulators of cambial activity, cell development and of the photoperiodic pathway. Reconfiguration of carbon allocation figured centrally in the tree's overwintering preparations. For example, genes associated with carbon-based defences such as terpenoids were down-regulated, while many genes associated with protein-based defences and other stress mitigation mechanisms were up-regulated. Several of these correspond to proteins that were accumulated during the growth-to-dormancy transition, emphasizing the importance of stress protection in the tree's adaptive response to overwintering. © 2011 Blackwell Publishing Ltd.

  9. Maturation of seeds of Caesalpinia echinata Lam. (Brazilwood, an endangered leguminous tree from the Brazilian Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Igor Ferrari Borges

    2005-11-01

    Full Text Available The present work describes changes during the maturation process of seeds of Caesalpinia echinata Lam. Individual flowers were tagged in the day of their anthesis and the pods were collected directly from the branches from 32 to 65 days after flowering (DAF. Results obtained suggested that physiological maturity of C. echinata seeds occurred ca. 60-65 DAF, immediately before shedding, when seeds had 30-40% water content.Sementes de Caesalpinia echinata Lam. têm sido consideradas como de curta longevidade. Contudo, quando lotes são submetidos à seleção prévia ao armazenamento, é possível conservar sua viabilidade por até 18 meses. Considerando a falta de informações conclusivas quanto à melhor época de colheita dessas sementes, o presente trabalho descreve as modificações que ocorrem durante o processo de maturação das sementes. Flores foram etiquetadas no dia de sua antese e os frutos foram colhidos diretamente dos ramos dos 32 aos 65 dias após a antese (DAA. Sementes dispersas naturalmente por período não superior a 24 horas também foram coletadas, sendo designadas sementes recém-dispersas. As características externas e as dimensões (comprimento, largura e espessura de frutos e sementes foram registradas. A avaliação da qualidade fisiológica das sementes foi baseada no teor de água, no conteúdo de matéria seca e na germinação. Os resultados sugerem que a maturidade fisiológica das sementes de C. echinata ocorreu por volta de 60-65 DAA, imediatamente antes da deiscência, quando as sementes tinham 30-40% de água.

  10. Influences of vegetation structure and elevation on CO2 uptake in a mature jack pine forest in Saskatchewan, Canada

    International Nuclear Information System (INIS)

    Chasmer, L.; McCaughey, H.; Treitz, P.

    2008-01-01

    Eddy covariance (EC) is often used to measure the movement and direction of energy and trace gas concentrations in ecosystems. Data from EC networks are often combined with remote sensing data and ecosystem models in order to assess the spatial and temporal variability of carbon dioxide (CO 2 ) exchanges within specific areas of interest. This study presented a new method of determining changes in the structural characteristics of biomass and elevation. Lidar was used within the contours of half-hourly flux footprint areas to characterize vegetation structure and elevation. The influences of vegetation structure and elevation on CO 2 concentrations were measured by EC and Lidar measurements for 3 mature growing periods at a mature jack pine site in Saskatchewan. Mensuration data were collected over 2 periods. Meteorological, CO 2 , and H2O flux measurements were collected for 30 minute periods each day. Statistical analyses were conducted to determine the influence of meteorological variables on vegetation structure. Footprint contour lines were then layered onto the canopy height models derived by the lidar data. Multiple regression equations were used to determine net ecosystem productivity (NEP) and gross ecosystem productivity (GEP) using meteorological variables, canopy fractional cover; and elevation, as well as the results obtained from a Landsberg equation. The study showed that differences in NEP variability were influenced by differences in canopy and ground surface characteristics within the site. EC measurements underestimated gross CO 2 fluxes by 5 per cent as the biomass was lower within the immediate vicinity of the EC network. It was concluded that canopy structures and elevation are important factors for determining annual carbon balances. 36 refs., 8 tabs., 9 figs

  11. Foliage efficiency of forest-forming species in the climatic gradients of Eurasia

    Directory of Open Access Journals (Sweden)

    V. A. Usoltsev

    2017-08-01

    Full Text Available The paperis of the scientific area of biogeography and devoted to a new aspect in the study of biological productivity of forest ecosystems on a geographical basis, expressed indirectly by climate parameters, namely, the foliage efficiency that until now is not investigated at the global level. Foliage efficiency is the ratio of net primary production (NPP to foliage biomass and is expressed in relative units. Some features of change of foliage efficiency of vicarious forest-forming species in Eurasian transcontinental gradients are showed for the first time using the voluminous factual material. The set of published biomass and NPP data (t/ha obtained in a number of 2192 plots is compiled. Using multiple regression analysis technique, the statistically significant changes in foliage efficiency values according to two transcontinental gradients, namely by zonal belts and continentality of climate, are stated for each forest-forming species. The species-specificity of age dynamics of stem volume and foliage efficiency is shown. It is monotonically decreased almost for all tree species in the following order: spruce and fir, pine, birch, oak, larch and aspen-poplar. When climate continentality increasing, foliage efficiency values of mature forests is dropping, most intensively in pines, less intensive in deciduous forests and virtually no changes in spruce-fir communities. In zonal gradient from the northern temperate to the subequatorial belt, foliage efficiency of deciduous species decreases, but it of the evergreen spruce and pine increases in the same direction. One of the possible causes of these opposite zonal trends of foliage efficiency in evergreen and deciduous species consists in different conditions of physiological processes in the year cycle, in particular, in year-round assimilates accumulation in the first and seasonal one in the second.

  12. Norway spruce crown structure changes under long-term multiple stress impact in Central European Mts

    Czech Academy of Sciences Publication Activity Database

    Moravec, Ivo; Cudlín, Pavel; Polák, T.

    2003-01-01

    Roč. 22, Suppl. 1 (2003), s. 252-255 ISSN 1335-342X. [Long Term Air Pollution Effect on Forest Ecosystems (International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems)/20./. Zvolen, 30.08.2002-01.09.2002] R&D Projects: GA MŠk OK 355 Institutional research plan: CEZ:AV0Z6087904 Keywords : Norway spruce * crown transformation * tree status Subject RIV: EH - Ecology, Behaviour Impact factor: 0.100, year: 2003

  13. Fine root status element contents in three Norway spruce stands in the Krkonose Mts

    Czech Academy of Sciences Publication Activity Database

    Goldbold, D.; Fritz, H.; Cudlín, Pavel; Bonifacio, E.

    2003-01-01

    Roč. 22, Suppl. 1 (2003), s. 91-94 ISSN 1335-342X. [Long Term Air Pollution Effect on Forest Ecosystems (International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems)/20./. Zvolen, 30.08.2002-01.09.2002] R&D Projects: GA MŠk OK 355 Institutional research plan: CEZ:AV0Z6087904 Keywords : Ca:Al ratios, fine roots, spruce Subject RIV: EH - Ecology, Behaviour Impact factor: 0.100, year: 2003

  14. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia

    Directory of Open Access Journals (Sweden)

    Lopatin E

    2007-01-01

    Full Text Available When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

  15. Can aspen persist in conifer dominated forests?

    Science.gov (United States)

    Douglas H. Page; John D. Shaw

    2016-01-01

    In 1998 we measured a large, old aspen in a mixed spruce-fir-aspen forest on the Utah State University T.W. Daniel Experimental Forest in northern Utah. The tree was 297 years old - about the same age as the oldest spruce in the stand. A search of the forestry literature revealed that the oldest published age for an aspen came from a tree in the Sierra Nevada Range in...

  16. Determination of the terpene flux from orange species and Norway spruce by relaxed eddy accumulation

    DEFF Research Database (Denmark)

    Christensen, C.S.; Hummelshøj, P.; Jensen, N.O.

    2000-01-01

    Terpene fluxes from a Norway spruce (Picea abies) forest and an orange orchard (Citrus clementii and Citrus sinensis) were measured by relaxed eddy accumulation (REA) during summer 1997. alpha-pinene and beta-pinene were the most abundant terpenes emitted from Norway spruce and constituted approx...... rate by using two precision pumps operated at approximately 60 mi min(-1). The terpenes collected on the adsorbent tubes were significantly decomposed by ozone during sampling unless ozone scrubbers were applied. (C) 2000 Elsevier Science Ltd. All rights reserved....

  17. Effects of rainfall exclusion on leaf gas exchange traits and osmotic adjustment in mature canopy trees of Dryobalanops aromatica (Dipterocarpaceae) in a Malaysian tropical rain forest.

    Science.gov (United States)

    Inoue, Yuta; Ichie, Tomoaki; Kenzo, Tanaka; Yoneyama, Aogu; Kumagai, Tomo'omi; Nakashizuka, Tohru

    2017-10-01

    Climate change exposes vegetation to unusual levels of drought, risking a decline in productivity and an increase in mortality. It still remains unclear how trees and forests respond to such unusual drought, particularly Southeast Asian tropical rain forests. To understand leaf ecophysiological responses of tropical rain forest trees to soil drying, a rainfall exclusion experiment was conducted on mature canopy trees of Dryobalanops aromatica Gaertn.f. (Dipterocarpaceae) for 4 months in an aseasonal tropical rain forest in Sarawak, Malaysia. The rainfall was intercepted by using a soft vinyl chloride sheet. We compared the three control and three treatment trees with respect to leaf water use at the top of the crown, including stomatal conductance (gsmax), photosynthesis (Amax), leaf water potential (predawn: Ψpre; midday: Ψmid), leaf water potential at turgor loss point (πtlp), osmotic potential at full turgor (π100) and a bulk modulus of elasticity (ε). Measurements were taken using tree-tower and canopy-crane systems. During the experiment, the treatment trees suffered drought stress without evidence of canopy dieback in comparison with the control trees; e.g., Ψpre and Ψmid decreased with soil drying. Minimum values of Ψmid in the treatment trees decreased during the experiment, and were lower than πtlp in the control trees. However, the treatment trees also decreased their πtlp by osmotic adjustment, and the values were lower than the minimum values of their Ψmid. In addition, the treatment trees maintained gs and Amax especially in the morning, though at midday, values decreased to half those of the control trees. Decreasing leaf water potential by osmotic adjustment to maintain gs and Amax under soil drying in treatment trees was considered to represent anisohydric behavior. These results suggest that D. aromatica may have high leaf adaptability to drought by regulating leaf water consumption and maintaining turgor pressure to improve its leaf

  18. In vivo function of Pgβglu-1 in the release of acetophenones in white spruce

    Directory of Open Access Journals (Sweden)

    Melissa H. Mageroy

    2017-07-01

    Full Text Available Eastern spruce budworm (Choristoneura fumiferiana Clemens (ESBW is a major forest pest which feeds on young shoots of white spruce (Picea glauca and can cause landscape level economic and ecological losses. Release of acetophenone metabolites, piceol and pungenol, from their corresponding glycosides, picein and pungenin, can confer natural resistance of spruce to ESBW. A beta-glucosidase gene, Pgβglu-1, was recently discovered and the encoded enzyme was characterized in vitro to function in the release of the defensive acetophenone aglycons. Here we describe overexpression of Pgβglu-1 in a white spruce genotype whose metabolome contains the glucosylated acetophenones, but no detectable amounts of the aglycons. Transgenic overexpression of Pgβglu-1 resulted in release of the acetophenone aglycons in planta. This work provides in vivo evidence for the function of Pgβglu-1.

  19. From a tree to a stand in Finnish boreal forests - biomass estimation and comparison of methods

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chunjiang

    2009-07-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61deg50' N, 24deg22' E). In particular, a comparison of the results of different estimation methods was conducted to assess the reliability and suitability of their applications. For the trees in Mature-Stand, annual stem biomass increment fluctuated following a sigmoid equation, and the fitting curves reached a maximum level (from about 1 kg yr-1 for understorey spruce to 7 kg yr-1 for dominant pine) when the trees were 100 years old). Tree biomass was estimated to be about 70 Mg ha-1 in Young-Stand and about 220 Mg ha-1 in Mature-Stand. In the region (58.00-62.13 degN, 14-34 degE, <= 300 m a.s.l.) surrounding the study stands, the tree biomass accumulation in Norway spruce and Scots pine stands followed a sigmoid equation with stand age, with a maximum of 230 Mg ha-1 at the age of 140 years. In Mature-Stand, lichen biomass on the trees was 1.63 Mg ha-1 with more than half of the biomass occurring on dead branches, and the standing crop of litter lichen on the ground was about 0.09 Mg ha-1. There were substantial differences among the results estimated by different methods in the stands. These results imply that a possible estimation error should be taken into account when calculating tree biomass in a stand with an indirect approach. (orig.)

  20. Responses of soil Collembola to long-term atmospheric CO2 enrichment in a mature temperate forest

    International Nuclear Information System (INIS)

    Xu Guoliang; Fu Shenglei; Schleppi, Patrick; Li Maihe

    2013-01-01

    Responses of Collembola to 7 years of CO 2 enrichment (550 ppm) in a Swiss free-air CO 2 enrichment (FACE) experiment in a forest with 80- to 120-year-old trees were investigated in this study. Contrary to our expectations, increased CO 2 caused a significant decrease in Collembola numbers, including a significant decrease in euedaphic Collembola. Increased CO 2 , however, did not affect community group richness. Collembola biomass was not significantly changed by CO 2 enrichment, regardless of whether it was considered in terms of the total community, life-strategy groups, or individual species (with an exception of Mesaphorura krausbaueri). The reason for this is that CO 2 enrichment caused a general increase in individual body size, which compensated for reduced abundances. The results are consistent with the idea that the rhizosphere is important for soil fauna, and the combination of reduced fine root growth and increased soil moisture might trigger a reduction in Collembola abundance. - Highlights: ► Increased CO 2 caused a significant decrease in Collembola abundance. ► Increased CO 2 caused a significant decrease in euedaphic Collembola. ► Collembola body size tended to be larger. ► A decrease in fine roots biomass might trigger the reduction in Collembola. - Seven years of CO 2 enrichment caused a significant decrease in Collembola abundance, especially in euedaphic species.

  1. Experimental warming delays autumn senescence in a boreal spruce bog: Initial results from the SPRUCE experiment

    Science.gov (United States)

    Richardson, Andrew; Furze, Morgan; Aubrecht, Donald; Milliman, Thomas; Nettles, Robert; Krassovski, Misha; Hanson, Paul

    2016-04-01

    Phenology is considered one of the most robust indicators of the biological impacts of global change. In temperate and boreal regions, long-term data show that rising temperatures are advancing spring onset (e.g. budburst and flowering) and delaying autumn senescence (e.g. leaf coloration and leaf fall) in a wide range of ecosystems. While warm and cold temperatures, day length and insolation, precipitation and water availability, and other factors, have all been shown to influence plant phenology, the future response of phenology to rising temperatures and elevated CO2 still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments to simulate future environmental conditions. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9° C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers, at both the individual and whole-community level, using repeat digital photography. Within each chamber, digital camera images are recorded every 30 minutes and uploaded to the PhenoCam (http://phenocam.sr.unh.edu) project web page, where they are displayed in near-real-time. Image processing is conducted nightly to extract quantitative measures of canopy color, which we characterize using Gcc, the green chromatic coordinate. Data from a camera mounted outside the chambers (since November 2014) indicate strong seasonal variation in Gcc for both evergreen shrubs and trees. Shrub Gcc rises steeply in May and June, and declines steeply in September and October. By comparison, tree Gcc rises gradually from March through June, and declines gradually from

  2. Impact of elevated carbon dioxide concentration and temperature on bud burst and shoot growth of boreal Norway spruce

    International Nuclear Information System (INIS)

    Slaney, M.; Linder, S.

    2007-01-01

    Atmospheric carbon dioxide (CO 2 ) concentrations are predicted to double during the next century, and recent studies have suggested that temperature changes as a result of global warming will be pronounced over the mid and high latitudes of northern continents. The phenology of boreal forests is mainly driven by temperature, and is a reliable indicator of climate change. This article presented the results of a study investigating the effects of elevated carbon dioxide (CO 2 ) and temperature on bud and shoot phenology of mature Norway spruce trees grown in northern Sweden. The trees were grown in whole tree chambers over a period of 3 years and supplied with either ambient or elevated CO 2 at either ambient, or elevated temperatures, which were altered on a monthly time step based on simulations by the Swedish Regional Climate Modelling Program. Temperature elevation ranged between 2.8 and 5.6 degrees C above ambient temperatures, with a CO 2 elevation of 700 μmol per mol. Bud development and shoot extension were monitored from early spring until the termination of elongation growth. Results of the study showed that elevated air temperature hastened both bud development and the initiation and termination of shoot growth by 2 to 3 weeks in each of the study years. It was noted that elevated CO 2 had no significant effect on bud development patterns or on the length of the shoot growth period. Although there was a distinct correlation between temperature sum and shoot elongation, a precise timing of bud burst could not be obtained by using an accumulation of temperature sums. It was concluded that climate warming will results in earlier bud burst in boreal Norway spruce. 59 refs., 3 tabs., 7 figs

  3. Differential controls by climate and physiology over the emission rates of biogenic volatile organic compounds from mature trees in a semi-arid pine forest.

    Science.gov (United States)

    Eller, Allyson S D; Young, Lindsay L; Trowbridge, Amy M; Monson, Russell K

    2016-02-01

    Drought has the potential to influence the emission of biogenic volatile organic compounds (BVOCs) from forests and thus affect the oxidative capacity of the atmosphere. Our understanding of these influences is limited, in part, by a lack of field observations on mature trees and the small number of BVOCs monitored. We studied 50- to 60-year-old Pinus ponderosa trees in a semi-arid forest that experience early summer drought followed by late-summer monsoon rains, and observed emissions for five BVOCs-monoterpenes, methylbutenol, methanol, acetaldehyde and acetone. We also constructed a throughfall-interception experiment to create "wetter" and "drier" plots. Generally, trees in drier plots exhibited reduced sap flow, photosynthesis, and stomatal conductances, while BVOC emission rates were unaffected by the artificial drought treatments. During the natural, early summer drought, a physiological threshold appeared to be crossed when photosynthesis ≅2 μmol m(-2) s(-1) and conductance ≅0.02 mol m(-2) s(-1). Below this threshold, BVOC emissions are correlated with leaf physiology (photosynthesis and conductance) while BVOC emissions are not correlated with other physicochemical factors (e.g., compound volatility and tissue BVOC concentration) that have been shown in past studies to influence emissions. The proportional loss of C to BVOC emission was highest during the drought primarily due to reduced CO2 assimilation. It appears that seasonal drought changes the relations among BVOC emissions, photosynthesis and conductance. When drought is relaxed, BVOC emission rates are explained mostly by seasonal temperature, but when seasonal drought is maximal, photosynthesis and conductance-the physiological processes which best explain BVOC emission rates-decline, possibly indicating a more direct role of physiology in controlling BVOC emission.

  4. Forests

    International Nuclear Information System (INIS)

    Melin, J.

    1997-01-01

    Forests have the capacity to trap and retain radionuclides for a substantial period of time. The dynamic behaviour of nutrients, pollution and radionuclides in forests is complex. The rotation period of a forest stand in the Nordic countries is about 100 years, whilst the time for decomposition of organic material in a forest environment can be several hundred years. This means that any countermeasure applied in the forest environment must have an effect for several decades, or be reapplied continuously for long periods of time. To mitigate the detrimental effect of a contaminated forest environment on man, and to minimise the economic loss in trade of contaminated forest products, it is necessary to understand the mechanisms of transfer of radionuclides through the forest environment. It must also be stressed that any countermeasure applied in the forest environment must be evaluated with respect to long, as well as short term, negative effects, before any decision about remedial action is taken. Of the radionuclides studied in forests in the past, radiocaesium has been the main contributor to dose to man. In this document, only radiocaesium will be discussed since data on the impact of other radionuclides on man are too scarce for a proper evaluation. (EG)

  5. Biomass equations and biomass expansion factors (BEFs) for pine (pinus spp.), spruce (picea spp.) and broadleaved dominated stands in Norway

    OpenAIRE

    Viken, Knut Ole

    2012-01-01

    Abstract The objectives of this study were (1) to develop models for estimation of stand-level tree biomass for spruce (picea spp.)- pine (pinus spp.)- and broadleaved-dominated forest in Norway and, (2) develop biomass expansion factors (BEFs; ratio of stem volume to biomass) which convert stem volume to whole tree biomass for Norwegian forest conditions. A dataset from a 5 year period (2006 – 2010) from the Norwegian National Forest Inventory (NFI) were used to develop the...

  6. Forest insects and diseases in Kouchibouguac National Park in 1994. Technical note No. 306

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, G.R.

    1995-11-01

    Personnel of the Forest Insect and Disease Survey regularly survey national parks for forest insect and disease conditions. This document presents some of the conditions encountered in Kouchibouguac National Park in 1992, including balsam twig aphids, gypsy moth, whitespotted sawyer bettle, white pine weevil, frost damage, Eastern tent caterpiller, uglynest caterpillar, hypoxylon canker, spruce budmoth, Eastern spruce gall adelgid, and other pests encountered.

  7. Forest insects and diseases in Kouchibouguac National Park in 1992. Technical note No. 275. Annual publication

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, G.R.

    1993-01-01

    Personnel of the Forest Insect and Disease Survey regularly survey national parks for forest insect and disease conditions. This document presents some of the conditions encountered in Kouchibouguac National Park in 1992, including balsam twig aphids, gypsy moth, whitespotted sawyer bettle, white pine weevil, frost damage, Eastern tent caterpiller, uglynest caterpillar, hypoxylon canker, spruce budmoth, Eastern spruce gall adelgid, and other pests encountered.

  8. Forest insects and diseases in Kouchibouguac National Park in 1993. Technical note No. 295

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, G.R.

    1994-01-01

    Personnel of the Forest Insect and Disease Survey regularly survey national parks for forest insect and disease conditions. This document presents some of the conditions encountered in Kouchibouguac National Park in 1992, including balsam twig aphids, gypsy moth, whitespotted sawyer bettle, white pine weevil, frost damage, Eastern tent caterpiller, uglynest caterpillar, hypoxylon canker, spruce budmoth, Eastern spruce gall adelgid, and other pests encountered.

  9. Forest health restoration in south-central Alaska: a problem analysis.

    Science.gov (United States)

    Darrell W. Ross; Gary E. Daterman; Jerry L. Boughton; Thomas M. Quigley

    2001-01-01

    A spruce beetle outbreak of unprecedented size and intensity killed most of the spruce trees on millions of acres of forest land in south-central Alaska in the 1990s. The tree mortality is affecting every component of the ecosystem, including the socioeconomic culture dependent on the resources of these vast forests. Based on information obtained through workshops and...

  10. Estimation of arboreal lichen biomass available to woodland caribou in Hudson Bay lowland black spruce sites

    Directory of Open Access Journals (Sweden)

    Sarah K. Proceviat

    2003-04-01

    Full Text Available An arboreal lichen index to be utilized in assessing woodland caribou habitat throughout northeastern Ontario was developed. The "index" was comprised of 5 classes, which differentiated arboreal lichen biomass on black spruce trees, ranging from maximal quantities of arboreal lichen (class 5 to minimal amounts of arboreal lichen (class 1. This arboreal lichen index was subsequently used to estimate the biomass of arboreal lichen available to woodland caribou on lowland black spruce sites ranging in age from 1 year to 150 years post-harvest. A total of 39 sites were assessed and significant differences in arboreal lichen biomass were found, with a positive linear relationship between arboreal lichen biomass and forest age. It is proposed that the index be utilized by government and industry as a means of assessing the suitability of lowland black spruce habitat for woodland caribou in this region.

  11. The Effect Of Enhanced UV-B Radiation On Norway Spruce (Picea Abies (L.) Karst.) And Consequences For The Mountain Forest; Ucinek Ultravijolicnega Sevanja Na Smreko (Picea abies (L.) Karst.) In Posledice Za Garski Gozdni Ekosistem

    Energy Technology Data Exchange (ETDEWEB)

    Trošt Sedej, T.

    2005-07-01

    NaNorway spruce trees from the sub alpine stand are exposed not only to high UV-B radiation but also to a complex of other environmental factors, such as high photosynthetically active radiation, extreme temperature conditions, deficient water and mineral supply, which might cause stress responses. Current year needles from the sub alpine stand exhibited lower photochemical efficiency and total chlorophyll content compared to samples from lower altitudes. The result suggested that young needles were most vulnerable to stress factors, since the protective mechanisms were not fully developed. Current+1 year needles from the sub alpine stand exhibited lower ETSvalues and higher total UV-B absorbing compounds, which may be interpreted as most successful protection against UVB radiation of current+1 year needles among the three needle age classes.Despite the obtained results, the effect of a single stress factor on spruce could not be easily drawn out. Still, we may assume that the spruce is quite tolerant to high UV-B radiation and other extreme environmental factors in the mountains. [Serbian] Rastline, ki uspevajo v gorah, so pogosto izpostavljene stresnim razmeram, predvsem pove ani jakosti sevanja UV-B, skrajnim temperaturnim razmeram ter pomanjkanju vode in hranil. Odziv smreke na okoljske razmere je kompleksen. Pri enoletnih iglicah v visokogorju smo izmerili manjšo fotokemi no u inkovitost in vsebnost klorofilov, kar kaže na ob utljivost mladih iglic, kjer zaš itni mehanizmi še niso dokon no razviti. Pri starejših iglicah razlika ni bila ve statisti no zna ilna, zato sklepamo, da se poškodbe v drugem in tretjem letu prepre ijo ali popravijo. Pri dveletnih iglicah smreke z visokogorskega rastiš a je bil dihalni potencial zna ilno manjši in vsebnost UV-B absorbirajo ih snovi zna ilno ve ja, kar pojasnjujemo s tem, da so dveletne iglice z visokogorskega rastiš a med tremi starostnimi razredi najbolj odporne proti UV-B sevanju. Iz rezultatov sicer ne moremo

  12. Spruce aphid (Elatobium abietinum Walker) (Hemiptera: Aphididae) [Chapter XXIV

    Science.gov (United States)

    Ann M. Lynch

    2014-01-01

    Elatobium abietinum Walker is a spruce-feeding aphid that in Europe is referred to as the green spruce aphid (Day et al., 1998a) (Fig. 1). However, in North America E. abietinum is known simply as the spruce aphid, while the common name "green spruce aphid" refers to a different species, Cinara fornacula Hottes (Hemiptera: Aphididae) (http://www.entsoc.org/...

  13. Damage by the Sitka spruce weevil (Pissodes strobi) and growth patterns for 10 spruce species and hybrids over 26 years in the Pacific Northwest.

    Science.gov (United States)

    Russel G. Mitchell; Kenneth H. Wright; Norman E. Johnson

    1990-01-01

    Ten species and hybrids of spruce (Picea spp.) were planted and observed annually for 26 years at three coastal locations in Oregon and Washington to evaluate growth rates and susceptibility to the Sitka spruce weevil (= white pine weevil), Pissodes strobi The 10 spruce were: Sitka spruce, Norway spruce, Lutz spruce, black...

  14. Carbon sequestration by young Norway spruce monoculture

    Science.gov (United States)

    Pokorny, R.; Rajsnerova, P.; Kubásek, J.

    2012-04-01

    Many studies have been focused on allometry, wood-mass inventory, carbon (C) sequestration, and biomass expansion factors as the first step for the evaluation of C sinks of different plant ecosystems. To identify and quantify these terrestrial C sinks, and evaluate CO2 human-induced emissions on the other hand, information for C balance accounting (for impletion of commitment to Kyoto protocol) are currently highly needed. Temperate forest ecosystems have recently been identified as important C sink. Carbon sink might be associated with environmental changes (elevated [CO2], air temperature, N deposition etc.) and large areas of managed fast-growing young forests. Norway spruce (Pice abies L. Karst) is the dominant tree species (35%) in Central European forests. It covers 55 % of the total forested area in the Czech Republic, mostly at high altitudes. In this contribution we present C sequestration by young (30-35 year-old) Norway spruce monocultures in highland (650-700 m a.s.l., AT- mean annual temperature: 6.9 ° C; P- annual amount of precipitation: 700 mm; GL- growing season duration: 150 days) and mountain (850-900 m a.s.l.; AT of 5.5 ° C; P of 1300 mm; and GL of 120 days) areas and an effect of a different type of thinning. However, the similar stem diameter at the breast height and biomass proportions among above-ground tree organs were obtained in the both localities; the trees highly differ in their height, above-ground organ's biomass values and total above ground biomass, particularly in stem. On the total mean tree biomass needle, branch and stem biomass participated by 22 %, 24 % and 54 % in highland, and by 19 %, 23 % and 58 % in mountain area, respectively. Silvicultural management affects mainly structure, density, and tree species composition of the stand. Therefore, dendrometric parameters of a tree resulted from genotype, growth conditions and from management history as well. Low type of thinning (LT; common in highland) stimulates rather tree

  15. Near real time/low latency data collection for climate warming manipulations and an elevated CO2 SPRUCE experiment

    Science.gov (United States)

    Krassovski, M.; Hanson, P. J.; Riggs, J. S.; Nettles, W. R., IV

    2017-12-01

    Climate change studies are one of the most important aspects of modern science and related experiments are getting bigger and more complex. One such experiment is the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE, http://mnspruce.ornl.gov) conducted in in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). The SPRUCE experimental mission is to assess ecosystem-level biological responses of vulnerable, high carbon terrestrial ecosystems to a range of climate warming manipulations and an elevated CO2 atmosphere. This manipulation experiment generates a lot of observational data and requires a reliable onsite data collection system, dependable methods to transfer data to a robust scientific facility, and real-time monitoring capabilities. This presentation shares our experience of establishing near real time/low latency data collection and monitoring system using satellite communication.

  16. Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

    International Nuclear Information System (INIS)

    Boggs, Johnny L.; McNulty, Steven G.; Pardo, Linda H.

    2007-01-01

    We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999, we observed a significant correlation between mean growing season temperature and red spruce basal area growth. Red spruce and deciduous foliar %N correlated significantly with N deposition. Although N deposition has not changed significantly from 1987/1988 to 1999, net nitrification potential decreased significantly at Whiteface. This decrease in net potential nitrification is not consistent with the N saturation hypothesis and suggests that non-N deposition controls, such as climatic factors and immobilization of down dead wood, might have limited N cycling. - Data from the 1999 remeasurement of the red spruce forests suggest that N deposition, to some extent, is continuing to influence red spruce across the northeastern US as illustrated by a significant correlation between N deposition and red spruce foliar %N. Our data also suggest that the decrease in forest floor %N and net nitrification potential across sites from 1987 to 1999 may be due to factors other than N deposition, such as climatic factors and N immobilization in fine woody material (<5 cm diameter)

  17. [Carbon sequestration status of forest ecosystems in Ningxia Hui Autonomous Region].

    Science.gov (United States)

    Gao, Yang; Jin, Jing-Wei; Cheng, Ji-Min; Su, Ji-Shuai; Zhu, Ren-Bin; Ma, Zheng-Rui; Liu, Wei

    2014-03-01

    Based on the data of Ningxia Hui Autonomous Region forest resources inventory, field investigation and laboratory analysis, this paper studied the carbon sequestration status of forest ecosystems in Ningxia region, estimated the carbon density and storage of forest ecosystems, and analyzed their spatial distribution characteristics. The results showed that the biomass of each forest vegetation component was in the order of arbor layer (46.64 Mg x hm(-2)) > litterfall layer (7.34 Mg x hm(-2)) > fine root layer (6.67 Mg x hm(-2)) > shrub-grass layer (0.73 Mg x hm(-2)). Spruce (115.43 Mg x hm(-2)) and Pinus tabuliformis (94.55 Mg x hm(-2)) had higher vegetation biomasses per unit area than other tree species. Over-mature forest had the highest arbor carbon density among the forests with different ages. However, the young forest had the highest arbor carbon storage (1.90 Tg C) due to its widest planted area. Overall, the average carbon density of forest ecosystems in Ningxia region was 265.74 Mg C x hm(-2), and the carbon storage was 43.54 Tg C. Carbon density and storage of vegetation were 27.24 Mg C x hm(-2) and 4.46 Tg C, respectively. Carbon storage in the soil was 8.76 times of that in the vegetation. In the southern part of Ningxia region, the forest carbon storage was higher than in the northern part, where the low C storage was mainly related to the small forest area and young forest age structure. With the improvement of forest age structure and the further implementation of forestry ecoengineering, the forest ecosystems in Ningxia region would achieve a huge carbon sequestration potential.

  18. Long-distance dispersal of spruce budworm (Choristoneura fumiferana Clemens) in Minnesota (USA) and Ontario (Canada) via the atmospheric pathway

    Science.gov (United States)

    Brian R. Sturtevant; Gary L. Achtemeier; Joseph J. Charney; Dean P. Anderson; Barry J. Cooke; Phillip A. Townsend

    2013-01-01

    Dispersal can play an important role in the population dynamics of forest insects, but the role of long-distance immigration and emigration remains unclear due to the difficulty of quantifying dispersal distance and direction. We designed an agent-based spruce budworm flight behavior model that, when interfaced with temperature, wind speed, and precipitation output...

  19. Recent evolution and divergence among populations of a rare Mexican endemic, Chihuahua spruce, following holocene climatic warming

    Science.gov (United States)

    F. Thomas Ledig; Virginia Jacob-Cervantes; Paul D. Hodgskiss

    1997-01-01

    Fragmentation and reduction in population size are expected to reduce genetic diversity. However, examples from natural populations of forest trees are scarce. The range of Chihuahua spruce retreated northward and fragmented coincident with the warming climate that marked the early Holocene. The isolated populations vary from 15 to 2441 trees, which provided an...

  20. Bioecology of the conifer swift moth, Korscheltellus gracilis, a root feeder associated with spruce-fir decline

    Science.gov (United States)

    William E. Wallner; David L. Wagner; Bruce L. Parker; Donald L. Tobi

    1991-01-01

    During the past two decades, the decline of red spruce, Picea rubens Sargent, and balsam fir, Abies balsamea (L), at high elevations (900-1200 m) in eastern North America has evoked concern about the effects of anthropogenic deposition upon terrestrial ecosystems. In many high-elevation forests across New England, as many as 50...

  1. Culturable bacterial populations associated with ectomycorrhizae of Norway spruce stands with different degrees of decline in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Avidano, L.; Rinaldi, M.; Gindro, R.; Cudlín, Pavel; Martinotti, M G.; Fracchia, L.

    2010-01-01

    Roč. 56, č. 1 (2010), s. 52-64 ISSN 0008-4166 Institutional research plan: CEZ:AV0Z60870520 Keywords : Ectomycorrhizae * Norway spruce * forest decline Subject RIV: EE - Microbiology, Virology Impact factor: 1.235, year: 2010

  2. The Biomonitoring project – monitoring of forest ecosystems in non-intervention areas of the Šumava National Park

    Czech Academy of Sciences Publication Activity Database

    Zenáhlíková, J.; Červenka, J.; Čížková, P.; Bečka, P.; Starý, M.; Marek, P.; Křenová, Zdeňka; Svoboda, M.

    2015-01-01

    Roč. 21, č. 1 (2015), s. 95-104 ISSN 1211-7420 Institutional support: RVO:67179843 Keywords : Bohemian forest * forest inventory * dead wood * natural regeneration * Norway spruce Subject RIV: EH - Ecology, Behaviour

  3. Elevated bark temperature in unremoved stumps after disturbances facilitates multi-voltinism in Ips typographus population in a mountainous forest

    Directory of Open Access Journals (Sweden)

    Fleischer Peter

    2016-03-01

    Full Text Available The number of Ips typographus generations developed in a year might be indicative of its population size and of risk to Norway spruce forests. Warm weather and unremoved fallen trees after natural disturbances are thought of as key factors initiating large population increase. We studied I. typographus development in a spruce forest of the Tatra National Park, which was heavily affected by large-scale disturbances in the last decade. Repeated windthrows and consequent bark beetle outbreaks have damaged almost 20,000 hectares of mature Norway spruce forests, what is a half of the National Park forest area. Current I. typographus population size and its response to the environment and to forestry defense measures attract attention of all stakeholders involved in natural resource management, including public. In this paper we analyse the potential I. typographus population size in two consecutive years 2014 and 2015, which represented a climatologically normal year and an extremely hot year, respectively. We used bark temperature and phenology models to estimate the number of generations developed in each year. In 2014, the average bark temperature of standing living trees at study sites was 14.5 °C, in 2015 it increased to 15.7 °C. The bark temperature of fallen logs was 17.7 °C in 2014, and 19.5 °C in 2015. The bark temperature of standing living trees allowed to develop one and two generations in 2014 and 2015, respectively. The elevated bark temperature of fallen logs allowed to develop two generations in 2014 and three generations in 2015. The good match between the predicted and observed timing of each generation emergence as well as the large increase in the number of catches in pheromone traps in 2015 indicated a dramatic increase of the I. typographus population in the extremely warm year, especially at the unmanaged windthrown site.

  4. Increased spruce tree growth in Central Europe since 1960s.

    Science.gov (United States)

    Cienciala, Emil; Altman, Jan; Doležal, Jiří; Kopáček, Jiří; Štěpánek, Petr; Ståhl, Göran; Tumajer, Jan

    2018-04-01

    Tree growth response to recent environmental changes is of key interest for forest ecology. This study addressed the following questions with respect to Norway spruce (Picea abies, L. Karst.) in Central Europe: Has tree growth accelerated during the last five decades? What are the main environmental drivers of the observed tree radial stem growth and how much variability can be explained by them? Using a nationwide dendrochronological sampling of Norway spruce in the Czech Republic (1246 trees, 266 plots), novel regional tree-ring width chronologies for 40(±10)- and 60(±10)-year old trees were assembled, averaged across three elevation zones (break points at 500 and 700m). Correspondingly averaged drivers, including temperature, precipitation, nitrogen (N) deposition and ambient CO 2 concentration, were used in a general linear model (GLM) to analyze the contribution of these in explaining tree ring width variability for the period from 1961 to 2013. Spruce tree radial stem growth responded strongly to the changing environment in Central Europe during the period, with a mean tree ring width increase of 24 and 32% for the 40- and 60-year old trees, respectively. The indicative General Linear Model analysis identified CO 2 , precipitation during the vegetation season, spring air temperature (March-May) and N-deposition as the significant covariates of growth, with the latter including interactions with elevation zones. The regression models explained 57% and 55% of the variability in the two tree ring width chronologies, respectively. Growth response to N-deposition showed the highest variability along the elevation gradient with growth stimulation/limitation at sites below/above 700m. A strong sensitivity of stem growth to CO 2 was also indicated, suggesting that the effect of rising ambient CO 2 concentration (direct or indirect by increased water use efficiency) should be considered in analyses of long-term growth together with climatic factors and N

  5. H and Al ionic toxicity in seedlings of spruce and beech trees

    Energy Technology Data Exchange (ETDEWEB)

    Rost-Siebert, K.

    1985-01-01

    The influence of aluminium and hydrogen on seedlings of spruce and beech trees was tested. Parameters as root growth, state of health, minerals content and production of dry matter were measured. The results are discussed and show that ion concentrations of hydrogen and aluminium, average for todays forest soils, reduce root growth, damage roots and disturb the uptake of Ca/sup 2+/ and Mg/sup 2+/.

  6. Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

    OpenAIRE

    Tremblay, Pascal; Boucher, Jean-Francois; Tremblay, Marc; Lord, Daniel

    2013-01-01

    Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP)) seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spr...

  7. Influence of sulfur dioxide on the mineral composition of needles from spruces

    Energy Technology Data Exchange (ETDEWEB)

    Materna, J

    1961-01-01

    Until recently all the authors knew about changes in the mineral composition of plants exposed to air pollution was that the sulfur content increases considerably. The question arises whether other mineral substances, too, accumulate in the assimilating organs of smoke injured plants, particularly cations such as calcium, potassium and magnesium. Results of analyses of spruce needles from an air polluted forest in the Erzebirge in Czechoslovakia yielded no relationship between the accumulation of sulfates and the mentioned cations.

  8. Estimation of Spruce Needle-Leaf Chlorophyll Content Based on DART and PARAS Canopy Reflectance Models

    Czech Academy of Sciences Publication Activity Database

    Yáñez-Rausell, L.; Malenovský, Z.; Rautiainen, M.; Clevers, J G P W.; Lukeš, Petr; Hanuš, Jan; Schaepman, M. E.

    2015-01-01

    Roč. 8, č. 4 (2015), s. 1534-1544 ISSN 1939-1404 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : Chlorophyll a plus b estimation * CHRIS-PROBA * coniferous forest * continuum removal * discrete anisotropic radiative transfer model (DART) * needle-leaf * Norway spruce * optical indices * PARAS * PROSPECT * radiative transfer * recollision probability Subject RIV: EH - Ecology, Behaviour Impact factor: 2.145, year: 2015

  9. Biomass of Sacrificed Spruce/Aspen (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and aspens in...

  10. Spruce needles used as radioecological biotracers

    International Nuclear Information System (INIS)

    Seidel, C.; Gruber, V.; Baumgartner, A.

    2009-01-01

    In a two years project spruce needle samples of the Austrian Bioindicator Grid were analysed by gamma-ray spectrometry to investigate the spatial and temporal distribution of radionuclides in spruce needles of the last 25 years with the main focus on the radioactive contamination before and after the Chernobyl fallout 1986. More than 600 spruce needle samples at selected locations of the Bioindicator Grid were analysed for different natural and anthropogenic radionuclides: 137 Cs, 40 K, 210 Pb, 226 Ra, 228 Ra, 238 U. Additionally, soil samples were taken at selected sites to study the soil-to-plant transfer. This radioecological evaluation is an important part of an existing environmental surveillance programme in Upper Austria in order to gain basic information on the impact of environmental changes on the radioecological behaviour of spruce trees. (orig.)

  11. Spectral differences of the functional crown parts and status of Norway spruce trees studied using remote sensing information

    Czech Academy of Sciences Publication Activity Database

    Malenovský, Zbyněk; Clevers, J G P W.; Arkima, H.; Kuosmanen, V.; Cudlín, Pavel; Polák, T.

    2003-01-01

    Roč. 22, Suppl. 1 (2003), s. 207-210 ISSN 1335-342X. [Long Term Air Pollution Effect on Forest Ecosystems (International Meeting for Specialists in Air Pollution Effects on Forest Ecosystems)/20./. Zvolen, 30.08.2002-01.09.2002] R&D Projects: GA MŠk OK 389 Institutional research plan: CEZ:AV0Z6087904 Keywords : Norway spruce * stress response * remote sensing Subject RIV: EH - Ecology, Behaviour Impact factor: 0.100, year: 2003

  12. Damages and causes of death in plantations with containerised seedlings of Scots pine and Norway spruce in the central of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Naumburg, Jan

    2000-07-01

    In 1972, 94 forest areas were planted with containerised seedlings, 83 with Scots pine (Pinus sylvestris L.) and 11 with Norway spruce (Picea abies (L.) Karst.), in the central of Sweden. In the first season after planting, 99% of the Scots pine and 98% of the Norway spruce seedlings survived. Three seasons after plantation, 67% of Scots pine and 62% of Norway spruce were alive. The most common type of known damages causing mortality were mammals and insects. Vegetation was registered as the cause of mortality at some occasions in Scots pine plantations, whereas vegetation never was considered as the cause of death in Norway spruce plantations. The average size of the scarification patches were 0.25 m{sup 2} and 0.4 m{sup 2} in Scots pine and Norway spruce respectively. In Scots pine plantations there were 1600 planted seedlings ha{sup -1} and in Norway spruce there were 1550 ha{sup -1}. After the third growing season, the numbers of main crop plants, including naturally regenerated hardwood and softwood plants, were 1500 ha{sup -1} for Scots pine and 1350 ha{sup -1} for Norway spruce. The studied plantings had been approved if the recommended number of seedlings had been planted. As there always is some mortality among planted seedlings, in the present study 35-40%, this phenomenon has to be taken into consideration when dimensioning the number of seedlings which are to be planted.

  13. Estimating Forest Carbon Stock in Alpine and Arctic Ecotones of the Urals

    Directory of Open Access Journals (Sweden)

    V. A. Usoltsev

    2014-10-01

    Full Text Available This paper reports on measured carbon stocks in the forests of two tree line ecotones of the Ural region where climate change might improve growing conditions. The first is an alpine ecotone that is represented by an altitudinal gradient of the spruce-dominated forests on the Western slope of the Tylaiskii Kamen Mountain (Western part of the Konzhakovskii-Tylaiskii-Serebryanskii Mountain system, 59°30′N, 59°00′E, at the alpine timber line that has risen from 864 to 960 m above sea level in the course of the last 100 years. The second is an arctic ecotone in larch-dominated forests at the lower course of the Pur river (67°N, 78°E, at the transition zone between closed floodplain forests and open or island-like communities of upland forests on tundra permafrost. According to our results, there are large differences in the carbon of the aboveground biomass of both ecotones across environmental gradients. In the alpine tree line ecotone, a 19-fold drop of the carbon stocks was detected between the lower and higher altitudinal levels. In the arctic ecotone the aboveground biomass carbon stock of forests of similar densities (1300 to 1700 trees per ha was 7 times as much in the river flood bed, and 5 times as much in mature, dense forests as the low density forests at higher elevations. Twelve regression equations describing dependencies of the aboveground tree biomass (stems, branches, foliage, total aboveground part upon stem diameter of the tree are proposed, which can be used to estimating the biological productivity (carbon of spruce and larch forests on Tylaiskii Kamen Mountain and the lower Pur river and on surrounding areas on the base of traditional forest mensuration have been proposed. In order to reduce the labor intensity of a coming determination of forest biomass the average values of density and dry matter content in the biomass fractions are given that were obtained by taking our sample trees.The results can be useful in

  14. Fluxes of trichloroacetic acid through a conifer forest canopy

    International Nuclear Information System (INIS)

    Stidson, R.T.; Heal, K.V.; Dickey, C.A.; Cape, J.N.; Heal, M.R.

    2004-01-01

    Controlled-dosing experiments with conifer seedlings have demonstrated an above-ground route of uptake for trichloroacetic acid (TCA) from aqueous solution into the canopy, in addition to uptake from the soil. The aim of this work was to investigate the loss of TCA to the canopy in a mature conifer forest exposed only to environmental concentrations of TCA by analysing above- and below-canopy fluxes of TCA and within-canopy instantaneous reservoir of TCA. Concentrations and fluxes of TCA were quantified for one year in dry deposition, rainwater, cloudwater, throughfall, stemflow and litterfall in a 37-year-old Sitka spruce and larch plantation in SW Scotland. Above-canopy TCA deposition was dominated by rainfall (86%), compared with cloudwater (13%) and dry deposition (1%). On average only 66% of the TCA deposition passed through the canopy in throughfall and stemflow (95% and 5%, respectively), compared with 47% of the wet precipitation depth. Consequently, throughfall concentration of TCA was, on average, ∼1.4 x rainwater concentration. There was no significant difference in below-canopy fluxes between Sitka spruce and larch, or at a forest-edge site. Annual TCA deposited from the canopy in litterfall was only ∼1-2% of above-canopy deposition. On average, ∼800 μg m -2 of deposited TCA was lost to the canopy per year, compared with estimates of above-ground TCA storage of ∼400 and ∼300 μg m -2 for Sitka spruce and larch, respectively. Taking into account likely uncertainties in these values (∼±50%), these data yield an estimate for the half-life of within-canopy elimination of TCA in the range 50-200 days, assuming steady-state conditions and that all TCA lost to the canopy is transferred into the canopy material, rather than degraded externally. The observations provide strong indication that an above-ground route is important for uptake of TCA specifically of atmospheric origin into mature forest canopies, as has been shown for seedlings (in

  15. Response of leaf and whole-tree canopy conductance to wet conditions within a mature premontane tropical forest in Costa Rica

    Science.gov (United States)

    Aparecido, L. M. T.; Miller, G. R.; Cahill, A. T.; Andrews, R.; Moore, G. W.

    2017-12-01

    Tropical water recycling and carbon storage are dependent on canopy-atmosphere dynamics, which are substantially altered when rainfall occurs. However, models only indirectly consider leaf wetness as a driving factor for carbon and water fluxes. To better understand how leaf wetness condition affects stomatal and canopy conductance to water vapor, we tested a set of widely used models for a mature tropical forest of Costa Rica with prolonged periods of wet leaves. We relied on a year of sap flux measurements from 26 trees to estimate transpiration (Ec) and multiple micrometeorological profile measurements from a 40-m tower to be used in the models. Stomatal conductance (gs) models included those proposed by Jones (1992) (gs-J), using shaded and sunlit leaf temperatures, and Monteith and Unsworth (1990) (gs-MU), using air temperature. Canopy conductance (gc) models included those proposed by McNaughton and Jarvis (1983) (gc-MJ) and Penman-Monteith (gc-PM). Between gs and gc, gc had the largest differences within models during dry periods; while estimates were most similar during wet periods. Yet, all gc and gs estimates on wet days were at least as high as on dry days, indicative of their insensitivity to leaf wetness. Shaded leaf gs averaged 26% higher than in sunlit leaves. Additionally, the highly decoupled interface (Ω>0.90) reflected multiple environmental drivers that may influence conductance (e.g. vapor pressure deficit and leaf temperature). This was also seen through large shifts of diurnal peaks of gs and gc (up to 2 hours earlier than Ec) associated with the daily variation of air temperature and net radiation. Overall, this study led to three major insights: 1) gc and gs cannot accurately be predicted under wet conditions without accounting for leaf wetness, 2) even during dry days, low vapor pressure deficits interfere with model accuracy, and 3) intermittent rain during semi-dry and wet days cause large fluctuations in gc and gs estimates. Thus, it

  16. Experimental Whole-Ecosystem Warming Alters Vegetation Phenology in a Boreal Spruce Bog: Initial Results from the SPRUCE Experiment

    Science.gov (United States)

    Richardson, A. D.

    2016-12-01

    Phenology is one of the most robust indicators of the biological impacts of global change. However, the response of phenology to future environmental conditions still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9°C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers using repeat digital photography. Within each chamber, images are recorded every 30 minutes and uploaded to PhenoCam (http://phenocam.sr.unh.edu), where processed to yield quantitative measures of canopy color. These data are complemented by on-the-ground phenological data collected by human observers. Air warming treatments at SPRUCE began in August 2015. We observed a delay in senescence during autumn 2015 (2-5 days per degree of warming) and an advance in onset during spring 2016 (1-4 days per degree of warming). These patterns are robust across species and methods of phenological observation (i.e. camera-based vs. human observer). And, our results show very little evidence for photoperiod acting as a constraint on the response to warming. Early spring onset and consequent loss of frost hardiness in the warmest chambers proved disadvantageous when a brief period of extreme cold (to -12°C in the control chambers, to -3°C in the +9°C chambers) followed a month of generally mild weather. Foliage mortality for both Larix and Picea was immediate and severe, although both species subsequently re-flushed. These results give support for the hypothesis that warming may enhance the likelihood of spring frost

  17. Assessing the impacts of climate change and nitrogen deposition on Norway spruce growth in Austria with BIOME-BGC

    Energy Technology Data Exchange (ETDEWEB)

    Eastaugh, Chris S.; Potzelsberger, Elisabeth; Hasenaueur, Hubert

    2011-03-15

    The purpose of this study is to determine if the climate change has had an apparent impact in Austrian forests. This research has been conducted on Norway spruce forests as this is the predominant species in Austria. Growth data between regions which have different temperature and precipitation trendsw was then compared, with results showing increased productivity in all regions thus implying that growth of the forest is driven by other factors than climate. This conclusion is consistent with previous studies supporting that forest growth is mainly driven by increasing nitrogen deposition.

  18. Experiences with the Haertel-Truebungstest at diagnosing injuries to spruce caused by atmospheric pollution

    Energy Technology Data Exchange (ETDEWEB)

    Pelz, E

    1958-01-01

    The Haertel-Truebungstest is based on the observation that spruce needles secrete more wax at the stomata in areas affected by atmospheric pollution than in areas without. The increased secretion of wax is taken for a symptom of injury caused by atmospheric pollution. The wax is extracted in boiling water and, after cooling down, the turbidity of the extract is measured quantitatively in a photometer. Investigations on spruce in Saxony and Thuringia confirm the tendency to increasing turbidity towards the source of smoke. A considerable dispersion of turbidity values however impairs the results of this method, so that a great number of samples must be used in order to find out a trend. The dispersion of turbidity values in spruce forests that are not directly influenced by atmospheric pollution substantially exceeds the dispersion of the +/- 1% of the turbidity value that was found by Haertel. As was stated by Haertel and Papesch, the dispersion of individual turbidity values grows with increasing doses of SO/sub 2/. In Saxony the individual smoke emissions so densely cover one another, that there are scarcely any areas without air pollution and, probably, a relation exists between this continuous influence of smoke and SO/sub 2/ and the dispersion of turbidity values. It may be, however, that the environmental factors have also a certain influence, as, on vast areas of Saxony, spruce is growing on sites that are not its natural habitat.

  19. Ash-forming elements in four Scandinavian wood species part 3: Combustion of five spruce samples

    Energy Technology Data Exchange (ETDEWEB)

    Werkelin, Johan; Lindberg, Daniel; Skrifvars, Bengt-Johan; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Piispankatu 8, FI-20500 Turku (Finland); Bostroem, Dan [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden)

    2011-01-15

    Forest residue is the remaining fraction after the outtake of timber, which comprises the tree tops and branches. It may as fuel cause damage to the combustion device through ash slagging and fouling. The objective of this work was to model the ash composition from well-specified samples of a spruce tree: wood, bark, twigs, needles, and shoots. Their ash at 1000 C was modelled using global chemical equilibrium calculations, and laboratory-made ash of the five samples was analyzed by XRD and SEM-EDXA. According to the results, the risk of slagging arises from the spruce foliage: molten alkali silicates from spruce needles and probably molten alkali phosphates from spruce shoots may cause problems in the furnace. Fouling caused by condensing alkali vapours can be produced by all five samples. The amount of alkali vapours in the flue gas was in the same order of magnitude for all five samples, in spite of large differences in their original alkali contents. (author)

  20. High-Titer Methane from Organosolv-Pretreated Spruce and Birch

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2017-02-01

    Full Text Available The negative impact of fossil fuels and the increased demand for renewable energy sources has led to the use of novel raw material sources. Lignocellulosic biomass could serve as a possible raw material for anaerobic digestion and production of biogas. This work is aimed at using forest biomass, both softwood (spruce and hardwood (birch, as a raw material for anaerobic digestion. We examined the effect of different operational conditions for the organosolv pretreatment (ethanol content, duration of treatment, and addition of acid catalyst on the methane yield. In addition, we investigated the effect of addition of cellulolytic enzymes during the digestion. We found that inclusion of an acid catalyst during organosolv pretreatment improved the yields from spruce, but it did not affect the yields from birch. Shorter duration of treatment was advantageous with both materials. Methane yields from spruce were higher with lower ethanol content whereas higher ethanol content was more beneficial for birch. The highest yields obtained were 185 mL CH4/g VS from spruce and 259.9 mL CH4/g VS from birch. Addition of cellulolytic enzymes improved these yields to 266.6 mL CH4/g VS and 284.2 mL CH4/g VS, respectively.

  1. Modeling Wood Fibre Length in Black Spruce (Picea mariana (Mill. BSP Based on Ecological Land Classification

    Directory of Open Access Journals (Sweden)

    Elisha Townshend

    2015-09-01

    Full Text Available Effective planning to optimize the forest value chain requires accurate and detailed information about the resource; however, estimates of the distribution of fibre properties on the landscape are largely unavailable prior to harvest. Our objective was to fit a model of the tree-level average fibre length related to ecosite classification and other forest inventory variables depicted at the landscape scale. A series of black spruce increment cores were collected at breast height from trees in nine different ecosite groups within the boreal forest of northeastern Ontario, and processed using standard techniques for maceration and fibre length measurement. Regression tree analysis and random forests were used to fit hierarchical classification models and find the most important predictor variables for the response variable area-weighted mean stem-level fibre length. Ecosite group was the best predictor in the regression tree. Longer mean fibre-length was associated with more productive ecosites that supported faster growth. The explanatory power of the model of fitted data was good; however, random forests simulations indicated poor generalizability. These results suggest the potential to develop localized models linking wood fibre length in black spruce to landscape-level attributes, and improve the sustainability of forest management by identifying ideal locations to harvest wood that has desirable fibre characteristics.

  2. The dynamics of aerosol behaviour and fate within spruce canopies

    International Nuclear Information System (INIS)

    Ould-Dada, Zitouni

    1996-01-01

    The current work was intended to provide data on aerosol inputs to forest ecosystems and their subsequent fate. The background to the project was the Chernobyl accident which highlighted the importance of forests and other semi-natural ecosystems as a link in the transfer of radioactivity to man. In the aftermath of the Chernobyl accident, forests were identified as a specific type of semi-natural ecosystem for which radioecological data were almost completely absent within the countries of the European Union. Information on radionuclide behaviour and transfer in forest ecosystems was therefore needed to establish and test radiological assessment models which can be used to evaluate the likely contribution to radiological dose-to-man contaminated forests may make. The objective of this study was thus to provide data on dry deposition, resuspension and field loss of aerosols to forest canopies, in particular those of Norway spruce (Picea abies), from wind tunnel experiments conducted with small scale 'model' canopies. An aerosol generation system was developed to produce aerosol particles in the size range of 0.13-1.37 μm (VMD). Particle size distributions can be controlled within desired limits and with sufficient stability over time allowing the technique to be suitable for use in extended aerosol deposition studies. A full scale dry deposition experiment using 0.82 μm (VMAD) uranium particles was performed in the wind tunnel using Norway spruce saplings of approximately 45 cm height. Deposition velocities (V g ) were obtained and these were related to meteorological measurements (wind speed, friction velocity, turbulence intensity) inside the wind tunnel and LAI of the canopy. The latter was divided into five horizontal layers and both horizontal and vertical variations in deposition were assessed. A V g value of 0.497 cm s -1 was obtained for the canopy as a whole with the highest and lowest fluxes of 2.85 x 10 -8 and 8.14 x 10 -9 μgU cm -2 s -1 occurring at

  3. Observation on the effect of gamma rays on spruce (Picea smithiana) seeds germination

    International Nuclear Information System (INIS)

    Sharma, S.K.

    1997-01-01

    Spruce (Picea smithiana) forests cover extensive areas in western Himalayas and account for 48.80% of the total conifer forest area and growing stock in the region. Baldwin studied the effect of x-rays on the seeds of conifers trees. A little work has been done on the genus Picea in respect of physical mutagens. Keeping this in consideration the present trial has been done at preliminary level to study the effect of gamma rays on the germination behaviour. (author). 3 refs., 1 tab

  4. Assessing soil calcium depletion following growth and harvesting of Sitka spruce plantation forestry in the acid sensitive Welsh uplands

    Directory of Open Access Journals (Sweden)

    B. Reynolds

    1998-01-01

    Full Text Available A simple mass balance has been used to estimate soil calcium depletion during the growth of a 50 year old Sitka spruce crop on acid, base-poor peaty podzol soils in upland Wales. Growth of the crop will deplete the soil calcium reserve by an amount (205 kg Ca ha-1 approximately equivalent to the exchangeable calcium pool to the bottom of the profile and equal to 14% of the total soil calcium reserve to the bottom of the B horizon. Despite these predictions, measurements of exchangeable calcium show no differences beneath mature forest and acid grassland, implying that i weathering rates in forest soils are greater than long-term estimates and predictions by the PROFILE soil chemistry model ii the trees can access other sources of calcium or iii there are significant errors in the mass balance. Following stem-only harvesting, growth of a 50 year old second rotation crop will lead to further depletion of soil calcium, but this amount (79 kg Ca ha-1, is less than for a second rotation crop following whole-tree harvesting (197 kg Ca ha-1. After the first crop, stem-only harvesting would allow a further 18 rotations before depletion of the total calcium reserve to the bottom of the B horizon. Whole-tree harvesting would allow for seven rotations after the first crop. These calculations assume that all sources of calcium are equally available to the crop. This can only be resolved by dynamic modelling of the calcium cycle at the ecosystem scale based on appropriate field measurements. The potential for significant soil acidification is therefore greater following whole-tree harvesting and, in line with current recommendations (Nisbet et al., 1997, this technique should probably be avoided on acidic, nutrient-poor soils unless remedial measures are included to enhance the soil base cation status.

  5. EVALUATION OF THE IMPACT OF THE ECKLONIA MAXIMA EXTRACT ON SELECTED MORPHOLOGICAL FEATURES OF YELLOW PINE, SPRUCE AND THUJA STABBING

    Directory of Open Access Journals (Sweden)

    Jacek Sosnowski Sosnowski

    2016-07-01

    Full Text Available The study was focused on the impact of an extract of Ecklonia maxima on selected morphological features of yellow pine (Pinus ponderosa Dougl. ex C. Lawson, prickly spruce (Picea pungens Engelm. Variety Glauca, thuja (Thuja occidentalis variety Smaragd. The experiment was established in April 12, 2012 on the forest nursery in Ceranów. April 15, 2013 was introduced research agent in the form of a spraying an aqueous solution extract of Ecklonia maxima with trade name Kelpak SL. Biologically active compounds in the extract are plant hormones: auxin and cytokinin. There were studied increment in plant height, needle length of yellow pine, twigs length in prickly spruce and thuja. The measurements of increment in length of twigs and needles were made in each case on the same, specially marked parts of plants and have carried them on the 27th of each month beginning in May and ending in September. The results were evaluated statistically using the analysis of variance. Medium differentiations were verified by Tukey's test at a significance level p ≤ 0.05. The study showed that the diversity of traits features in the experiment was depended on the extract, the tree species and the measurement time. The best results after the extract using showed a pine and spruce. Seaweed preparation contributed to increment increased of trees height for in the pine and spruce and the needles length of pine and twigs of spruce. The species showing no reaction to the extract was thuja.

  6. Structure and resilience of fungal communities in Alaskan boreal forest soils

    Science.gov (United States)

    D. Lee Taylor; Ian C. Herriott; Kelsie E. Stone; Jack W. McFarland; Michael G. Booth; Mary Beth Leigh

    2010-01-01

    This paper outlines molecular analyses of soil fungi within the Bonanza Creek Long Term Ecological Research program. We examined community structure in three studies in mixed upland, black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) forests and examined taxa involved in cellulose...

  7. Multi-sensor data fusion for estimating forest species composition and abundance in northern Minnesota

    Science.gov (United States)

    Peter P. Wolter; Phillip A. Townsend

    2011-01-01

    The magnitude, duration, and frequency of forest disturbance caused by the spruce budworm and forest tent caterpillar in northern Minnesota and neighboring Ontario, Canada have increased over the last century due to a shift in forest species composition linked to historical fire suppression, forest management, and pesticide application that has fostered increased...

  8. Distribution of Lepidopteran Larvae on Norway Spruce: Effects of Slope and Crown Aspect.

    Science.gov (United States)

    Kulfan, Ján; Dvořáčková, Katarína; Zach, Peter; Parák, Michal; Svitok, Marek

    2016-04-01

    Lepidoptera associated with Norway spruce, Picea abies (L.) Karsten, play important roles in ecosystem processes, acting as plant pests, prey for predators, and hosts for parasites and parasitoids. Their distribution patterns in spruce crowns and forests are only poorly understood. We examined how slope and crown aspect affect the occurrence and abundance of moth larvae on solitary spruce trees in a montane region in Central Europe. Moth larvae were collected from southern and northern crowns of trees growing on south- and north-facing slopes (four treatments) using emergence boxes at the end of winter and by the beating method during the growing season. Species responses to slope and crown aspect were not uniform. Treatment effects on moth larvae were stronger in the winter than during the growing season. In winter, the abundance of bud-boring larvae was significantly higher in northern than in southern crowns regardless of the slope aspect, while both slope and aspect had marginally significant effects on abundance of miners. During the growing season, the occurrence of free-living larvae was similar among treatments. Emergence boxes and beating spruce branches are complementary techniques providing valuable insights into the assemblage structure of moth larvae on Norway spruce. Due to the uneven distribution of larvae detected in this study, we recommend adoption of a protocol that explicitly includes sampling of trees from contrasting slopes and branches from contrasting crown aspect in all seasons. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Old lower stem bark lesions apparently caused by unsuccessful spruce beetle attacks still evident on live spruce trees years later

    Science.gov (United States)

    John S. Hard; Ken P. Zogas

    2010-01-01

    We examined old bark lesions on Lutz spruce in young stands on the Kenai Peninsula, Alaska, to determine their cause. Distribution of these lesions along lower stems was similar to the distribution of spruce beetle attacks during epidemics. These lesions apparently resulted from unsuccessful attacks by spruce beetles during the late 1980s and early 1990s and appear to...

  10. Effectiveness of polyethylene sheeting in controlling spruce beetles (Coleoptera: Scolytidae) in infested stacks of spruce firewood in Alaska.

    Science.gov (United States)

    Edward H. Holsten; Richard A. Werner

    1993-01-01

    Covering stacks of spruce firewood with either clear or black polyethylene sheeting does not raise log temperatures high enough to kill spruce beetle brood in the logs. Based on the results of this study, we do not recommend the use of polyethylene sheeting as a remedial measure for the reduction of spruce beetle brood in infested firewood or log decks in south-central...

  11. Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas

    International Nuclear Information System (INIS)

    Nieminen, Jouni K.; Räisänen, Mikko

    2013-01-01

    Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH 4 –N (2100%), the proportion of soil NO 3 –N, and the N concentration of spruce needles. CSS greatly reduced the abundances of enchytraeids, tardigrades and collembolans, but increased the proportion and abundance of bacterial-feeding nematodes irrespective of carbohydrate addition. A better stabilization method needs to be developed before CSS can be used as a forest fertilizer. -- Highlights: •Spruces were fertilized with anaerobically digested and composted sewage sludge (CSS). •CSS increased soil N, proportion of NO 3 –N, and N concentration of spruce needles. •CSS reduced the abundances of enchytraeids, tardigrades and collembolans. •CSS increased the proportion and abundance of bacterial-feeding nematodes. •Sucrose did not reduce N pools or counteract negative CSS effects on soil animals. -- Composting and carbohydrate addition do not mitigate the harmful effects of anaerobically digested sewage sludge in boreal forest soil

  12. The timing and nature of Late Quaternary vegetation changes in the northern Great Plains, USA and Canada: a re-assessment of the spruce phase

    Science.gov (United States)

    Yansa, Catherine H.

    2006-02-01

    This paper revises the chronology for the northward migration of Picea glauca (white spruce) across the northern Great Plains, following the recession of the Laurentide Ice Sheet, and reinterprets the species composition and structure of the late-glacial vegetation on the basis of pollen and plant-macrofossil analysis. The timing of spruce migration is based on 26 14C ages obtained from Picea macrofossils. The date for the appearance of white spruce in southern South Dakota, USA, remains unchanged, 12,600 14C yr BP (ca 15,000 cal yr BP), but its arrival in southern Saskatchewan, Canada, by 10,300 14C yr BP (ca 12,100 cal yr BP) is about 1500 years later than previously estimated based on an organic sediment date. Picea glauca thus migrated northwards at an average rate of 0.38 km/ 14C year (0.30 km/calendar year), significantly slower than the previously published rate of 2 km/ 14C year. White spruce trees probably inhabited lake shorelines, whereas prairie, parkland, and boreal plants occupied both lowlands and uplands, forming an open white spruce parkland. This interpretation differs from a previous reconstruction of a boreal-type spruce forest and thus offers another paleoclimatic interpretation. Precipitation was probably low and summer temperatures relatively mild, averaging about 19 °C.

  13. Impacts of non-native Norway spruce plantation on abundance and species richness of ground beetles (Coleoptera: Carabidae

    Directory of Open Access Journals (Sweden)

    Z. Elek

    2001-06-01

    Full Text Available The impacts of non-native Norway spruce plantation on the abundance and species richness of carabids were studied in the Bükk National Park in Hungary, central Europe. Pitfall catches from recently established (5 yr old, young (15 yr after planting, middle-aged (30 yr after planting, old Norway spruce Picea abies plantation (50 yr after planting, and a native submontane beech forest (Fagetum sylvaticae as a control stand were compared.

    Our results showed that deciduous forest species decreased significantly in abundance in the plantations, and appeared in high abundance only in the native beech forest. Furthermore, open habitat species increased remarkably in abundance in the recently established plantation. Carabids were significantly more abundant and species rich in the native forest than in the plantations, while differences were not significant among the plantations. Multiple regression between the abundance and species richness of carabids and twelve environmental measurements showed that pH of the soil, herb cover and density of the carabids’ prey had a significant effect in determining abundance and species richness.

    Our results showed that plantation of non-native Norway spruce species had a detrimental effect on the composition of carabid communities and no regeneration could be observed during the growth of plantations even 50 yr after the establishment. This emphasises the importance of an active nature management practice to facilitate the recolonization of the native species.

  14. Concentrations of Ca and Mg in early stages of sapwood decay in red spruce, eastern hemlock, red maple, and paper birch

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Jody Jellison; Jon Connolly; Jonathan Schilling

    2007-01-01

    The decay of coarse woody debris is a key component in the formation of forest soil and in the biogeochemical cycles of Ca and Mg. We tracked changes in density and concentration of Ca and Mg in sapwood of red maple (Acer rubrum L.), red spruce (Picea rubens Sarg.), paper birch (Betula papyrifera Marsh.), and...

  15. Maturity Models

    DEFF Research Database (Denmark)

    Lasrado, Lester Allan; Vatrapu, Ravi

    2016-01-01

    Recent advancements in set theory and readily available software have enabled social science researchers to bridge the variable-centered quantitative and case-based qualitative methodological paradigms in order to analyze multi-dimensional associations beyond the linearity assumptions, aggregate...... effects, unicausal reduction, and case specificity. Based on the developments in set theoretical thinking in social sciences and employing methods like Qualitative Comparative Analysis (QCA), Necessary Condition Analysis (NCA), and set visualization techniques, in this position paper, we propose...... and demonstrate a new approach to maturity models in the domain of Information Systems. This position paper describes the set-theoretical approach to maturity models, presents current results and outlines future research work....

  16. Rainfall interception and spatial variability of throughfall in spruce stand

    Directory of Open Access Journals (Sweden)

    Dohnal Michal

    2014-12-01

    Full Text Available The interception was recognized as an important part of the catchment water balance in temperate climate. The mountainous forest ecosystem at experimental headwater catchment Liz has been subject of long-term monitoring. Unique dataset in terms of time resolution serves to determine canopy storage capacity and free throughfall. Spatial variability of throughfall was studied using one weighing and five tipping bucket rain gauges. The basic characteristics of forest affecting interception process were determined for the Norway spruce stand at the experimental area - the leaf area index was 5.66 - 6.00 m2 m-2, the basal area was 55.7 m2 ha-1, and the crown closure above individual rain gauges was between 19 and 95%. The total interception loss in both growing seasons analyzed was 34.5%. The mean value of the interception capacity determined was about 2 mm. Throughfall exhibited high variability from place to place and it was strongly affected by character of rainfall. On the other hand, spatial pattern of throughfall in average showed low variability.

  17. Dry deposition and fate of radionuclides within spruce canopies

    International Nuclear Information System (INIS)

    Ould-Dada, Z.; Shaw, G.; Kinnersley, R.P.; Minski, M.J.

    1997-01-01

    The assessment of radiation dose to human populations from the release of radionuclides into the atmosphere following a nuclear accident relies on the use of simulation models. These need to be calibrated and tested using experimental data. In this study, the deposition and resuspension of radionuclides within a forest environment was investigated. Forests were identified in the aftermath of the Chernobyl accident as a specific type of semi-natural ecosystem for which radiological data were lacking within the countries of the European Union. Wind tunnel and field data have been collected for small model canopies of Norwegian spruce saplings using uranium and silica aerosol particles. These have provided quantitative estimates of the potential of a tree canopy to constitute an airborne inhalation hazard and a secondary source of airborne contamination after the initial deposition. Using these results, a multi-layer compartmental model of aerosol flux (CANDEP) has been developed and calibrated. It combines the processes of dry deposition, resuspension and field loss in individual layers of the model canopy. (5 figures; 4 tables; 15 references). (UK)

  18. The measurement of Cs-137 in Latvian forest litter

    International Nuclear Information System (INIS)

    Riekstina, D.; Veveris, O.

    1998-01-01

    The role of forests in the distribution of cesium 137 over the Latvian territory affected by the Chernobyl accident was examined. Concentrations of this radionuclide in soil in pine, spruce, and birch forests and in non-forest areas in Rucava (affected by the accident) and in Taurene (non-polluted zone) were compared. In Rucava, the concentrations of Cs-137 fluctuated over the region of 108-724 Bq/kg in a pine forest, 205-2270 Bq/kg in a spruce forest, and 15-30 Bq/kg beyond the forest region. In Taurene, the corresponding figures were 42-157, 19-133, and 3-19 Bq/kg, respectively. The data confirm the appreciable role of coniferous forests in the absorption of Cs-137 from the air and its redistribution within the forest area. (P.A.)

  19. Interactions between near-ground temperature and radiation, silvicultural treatments and frost damage to Norway spruce seedlings

    OpenAIRE

    Langvall, Ola

    2000-01-01

    Several different silvicultural treatments were studied in two experiments. In the first, mechanical scarification, slash removal, vegetation control, clear-cut age and seedling types were investigated with respect to frost injury to Norway spruce (Picea abies (L.) Karst.) seedlings. Frost damage was also related to near-ground minimum temperature. In the other experiment, the effects of Scots pine (Pinus sylvestris (L.)) shelterwood density gradients, ranging from dense, uncut forest to comp...

  20. BVOC emission in Norway spruce: the effect of stand structure, high temperature and ozone levels.

    Science.gov (United States)

    Pallozzi, Emanuele; Guidolotti, Gabriele; Večeřová, Kristýna; Esposito, Raffaela; Lusini, Ilaria; Juráň, Stanislav; Urban, Otmar; Calfapietra, Carlo

    2015-04-01

    Norway spruce (Picea abies L.) is a widely distributed conifer species in the boreal zone and mountain areas of central Europe and is a moderate emitter of volatile organic compounds (BVOC). Although the vaporization and diffusion processes from resin ducts were generally considered to be the main processes for monoterpene emissions in conifers, recently it has been showed that a significant portion (up to one third) of monoterpene emissions of Norway spruce can originate from novel biosynthesis, thus depending on photosynthetic processes. For this reason, both biosynthesis and emission are strongly influenced by the environment and the stand structure. They increase with both increasing light and temperature during the warmer periods, although those are the periods with the higher ozone concentration that usually act as an inhibitor of both assimilation and isoprenoids synthesis and emission. On the other hand, stand structure can play an important role, because the photosynthetic capacity is influenced by temperature and light conditions through the canopy. In order to assess the effects of stand structure, temperature and ozone on isoprenoids emission of Norway spruce we carried out field and laboratory experiments. In the experimental field campaigns we measured: assimilation and BVOC emission from needles of sun and shade layers within the canopy of the spruce forest present at the Bily Kriz experimental research site (Moravian-Silesian Beskydy Mountains, 49° 33' N, 18° 32' E, NE of Czech Republic, 908 m a.s.l.). Moreover in the same layers we measured continuously concentration of BVOCs in the air using a PTR-TOF-MS. In laboratory we analyzed the effects of short-term exposure to high temperature and high ozone concentrations on branches of spruce trees collected at the Bily Kriz experimental research site. Preliminary results show that in Norway spruce both stand structure and environmental conditions influenced the gas exchange and BVOC emission rates

  1. Evaluation of IRS-1C LISS-3 satellite data for Norway spruce defoliation assessment

    Energy Technology Data Exchange (ETDEWEB)

    Falkenstroem, H.

    1999-02-01

    Satellite based remote sensing supported by air photo and field surveys, provide a means to area covering forest health assessment on a regional scale. Landsat TM data has been extensively used in studies of spruce and fir defoliation in Europe and North America. The temporal coverage of Landsat TM in combination with cloudiness however restrict the availability of data. In this study the LISS-3 sensor onboard the Indian Resource Satellite, IRS-1C, was evaluated for defoliation assessments in Norway spruce (Picea abies) in the central part of Sweden. The near infrared wavelength band proved to be best correlated with mean stand defoliation. After normalisation of satellite data for topographic conditions, the correlation coefficient increased from -0,19 to -0,83. Normalising satellite data for species composition did not improve the results though. The correction coefficients involved in the procedure were originally developed for Landsat TM, and proved to be inadequate for the LISS-3 data set. A thorough examination of the effects of species composition on LISS-3 data is needed to yield better results. The correlation between observed defoliation in the verification stands and predicted (based on the inverse regression function between corrected NIR values and defoliation in reference stands) was 0,70, despite a very limited range of defoliation in the verification set. IRS-1C LISS-3 is fully comparable to Landsat TM for spruce defoliation studies, although the results would probably not be significantly improved 49 refs, 7 figs, 10 tabs

  2. Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

    Directory of Open Access Journals (Sweden)

    Daniel Lord

    2013-06-01

    Full Text Available Open lichen woodlands (LWs are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spruce-feathermoss (BSFM stands. After one year, seedling survival and nutritional status were equivalent among stand types but despite higher root elongation index (REI, planted seedlings in LWs had lower relative growth rate, smaller total biomass and stem diameter than those in BSFM stands. Soil fertility variables, soil temperature, nor seedling water potential, helped at explaining this early growth response. Disc scarification significantly improved seedling first-year survival, biomass and foliar nutrient concentrations of P, Ca, and Mg. Smaller planting stock showed higher REI, higher shoot water potential, and higher foliar nutrient concentration of all but one of the measured nutrients (N, P, K and Mg. Hence, preliminary results suggest that planting of smaller containerized black spruce stock, combined with disc scarification, shows potential for afforestation of unproductive LWs. The impact of the lichen mat and other potential growth limiting factors on afforestation of these sites requires further investigation.

  3. Leaf area and light use efficiency patterns of Norway spruce under different thinning regimes and age classes

    Science.gov (United States)

    Gspaltl, Martin; Bauerle, William; Binkley, Dan; Sterba, Hubert

    2013-01-01

    Silviculture focuses on establishing forest stand conditions that improve the stand increment. Knowledge about the efficiency of an individual tree is essential to be able to establish stand structures that increase tree resource use efficiency and stand level production. Efficiency is often expressed as stem growth per unit leaf area (leaf area efficiency), or per unit of light absorbed (light use efficiency). We tested the hypotheses that: (1) volume increment relates more closely with crown light absorption than leaf area, since one unit of leaf area can receive different amounts of light due to competition with neighboring trees and self-shading, (2) dominant trees use light more efficiently than suppressed trees and (3) thinning increases the efficiency of light use by residual trees, partially accounting for commonly observed increases in post-thinning growth. We investigated eight even-aged Norway spruce (Picea abies (L.) Karst.) stands at Bärnkopf, Austria, spanning three age classes (mature, immature and pole-stage) and two thinning regimes (thinned and unthinned). Individual leaf area was calculated with allometric equations and absorbed photosynthetically active radiation was estimated for each tree using the three-dimensional crown model Maestra. Absorbed photosynthetically active radiation was only a slightly better predictor of volume increment than leaf area. Light use efficiency increased with increasing tree size in all stands, supporting the second hypothesis. At a given tree size, trees from the unthinned plots were more efficient, however, due to generally larger tree sizes in the thinned stands, an average tree from the thinned treatment was superior (not congruent in all plots, thus only partly supporting the third hypothesis). PMID:25540477

  4. Photosynthetic capacities of mature tropical forest trees in Rwanda are linked to successional group identity rather than to leaf nutrient content

    Science.gov (United States)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Adolfsson, Lisa; Niyonzima, Felix; Nsabimana, Donat; Uddling, Johan

    2014-05-01

    Tropical forests are crucial in the global carbon balance, yet information required to estimate how much carbon that enter these ecosystems through photosynthesis is very limited, in particular for Africa and for tropical montane forests. In order to increases the knowledge of natural variability of photosynthetic capacities in tropical tree species in tropical Africa, measurements of leaf traits and gas exchange were conducted on sun and shade leaves of ten tree species growing in two tropical forests in Rwanda in central Africa. Seven species were studied in Ruhande Arboretum, a forest plantation at mid altitude (1700 m), and six species in Nyungwe National Park, a cooler and higher altitude (at 2500 m) montane rainforest. Three species were common to both sites. At Nyungwe, three species each belonged to the successional groups pioneer and climax species. Climax species had considerably lower maximum rates of photosynthetic carboxylation (Vcmax) and electron transport (Jmax) than pioneer species. This difference was not related to leaf nutrient content, but rather seemed to be caused by differences in within-leaf N allocation between the two successional groups. With respect to N, leaves of climax species invested less N into photosynthetic enzymes (as judged by lower Vcmax and Jmax values) and more N into chlorophyll (as judged by higher SPAD values). Photosynthetic capacities, (i.e., Jmax and Vcmax), Jmax to Vcmax ratio and P content were significantly higher in Nyungwe than in Arboretum. Sun leaves had higher photosynthetic capacities and nutrient content than shade leaves. Across the entire dataset, variation in photosynthetic capacities among species was not related to leaf nutrient content, although significant relationships were found within individual species. This study contributes critical tropical data for global carbon models and suggests that, for montane rainforest trees of different functional types, successional group identity is a better

  5. Assessment of a relaxed eddy accumulation for measurements of fluxes of biogenic volatile organic compounds: Study over arable crops and a mature beech forest

    DEFF Research Database (Denmark)

    Gallagher, M.W.; Clayborough, R.; Beswick, K.M.

    2000-01-01

    A relaxed eddy accumulation (REA) system, based on the design by Beverland et al. (Journal of Geophysics Research 101 (D17) 22, 807-22, 815), for the measurement of biogenic VOC species was evaluated by intercomparison with an eddy correlation CO2 flux system over a mature deciduous beech canopy...... (Fagus Sylvatica) during the FOREXNOX program. Measurements from a site where winter wheat and barley (Hordeum Vulgare ann Triticum Aestivum) were being harvested are also presented. The system was inter-compared with two different eddy correlation systems for measuring CO2 fluxes. Good results were...

  6. Bat habitat use in White Mountain National Forest

    Science.gov (United States)

    Rachel A. Krusic; Mariko Yamasaki; Christopher D. Neefus; Peter J. Pekins

    1996-01-01

    In 1992 and 1993, we surveyed the foraging and feeding activity of bat species with broadband bat detectors at 2 foliage heights in 4 age classes of northern hardwood and spruce/fir forest stands in White Mountain National Forest, New Hampshire and Maine. The association of bat activity with trails and water bodies and the effect of elevation were measured. Mist nets,...

  7. Warming delays autumn declines in photosynthetic capacity in a boreal conifer, Norway spruce (Picea abies).

    Science.gov (United States)

    Stinziano, Joseph R; Hüner, Norman P A; Way, Danielle A

    2015-12-01

    Climate change, via warmer springs and autumns, may lengthen the carbon uptake period of boreal tree species, increasing the potential for carbon sequestration in boreal forests, which could help slow climate change. However, if other seasonal cues such as photoperiod dictate when photosynthetic capacity declines, warmer autumn temperatures may have little effect on when carbon uptake capacity decreases in these species. We investigated whether autumn warming would delay photosynthetic decline in Norway spruce (Picea abies (L.) H. Karst.) by growing seedlings under declining weekly photoperiods and weekly temperatures either at ambient temperature or a warming treatment 4 °C above ambient. Photosynthetic capacity was relatively constant in both treatments when weekly temperatures were >8 °C, but declined rapidly at lower temperatures, leading to a delay in the autumn decline in photosynthetic capacity in the warming treatment. The decline in photosynthetic capacity was not related to changes in leaf nitrogen or chlorophyll concentrations, but was correlated with a decrease in the apparent fraction of leaf nitrogen invested in Rubisco, implicating a shift in nitrogen allocation away from the Calvin cycle at low autumn growing temperatures. Our data suggest that as the climate warms, the period of net carbon uptake will be extended in the autumn for boreal forests dominated by Norway spruce, which could increase total carbon uptake in these forests. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Patterns of mast fruiting of common beech, sessile and common oak, Norway spruce and Scots pine in Central and Northern Europe

    DEFF Research Database (Denmark)

    Nussbaumer, Anita; Waldner, Peter; Etzold, Sophia

    2016-01-01

    Occurrence of mast years, i.e. the synchronous production of vast amounts of fruits or seeds, has an important impact on forest ecosystems, their functioning and their services. We investigated the mast patterns of the forest tree species common beech, common and sessile oak, Norway spruce...... and Scots pine in Central and Northern Europe over the last two to three decades. We analysed data from the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) and additional Danish, German, Flemish and Swiss datasets.Within-plot synchrony...

  9. Beech and spruce under the influence of electromagnetic radiation by radar

    International Nuclear Information System (INIS)

    Götz, G.; Matyssek, R.; Käs, G.

    2001-01-01

    Throughout a three-year study period beech and spruce trees were examined for potential effects of electromagnetic radiation by radar on the morphological and physiological performance at the crown level. No effects of radar on photosynthesis, transpiration, stomatal regulation as well as twig and foliage differentiation were found in late summer after seasonal exposure to this kind of radiation, when comparing radar-exposed with shielded crown parts. Adverse effects caused by radar on forest trees appear to be unlikely on a short-term scale, given conditions similar to those of this case study [de

  10. Feedbacks of windthrow for Norway spruce and Scots pine stands under changing climate

    International Nuclear Information System (INIS)

    Panferov, O; Rauch, E; Doering, C; Ahrends, B; Sogachev, A

    2009-01-01

    Wind damage is one of the major natural disturbances that can occur worldwide in most types of forests. Enhanced management using adequate decision support systems (DSS) can considerably reduce the risk of windthrow. The decision support system 'Forest and Climate Change' (DSS-WuK) which is currently being developed at Goettingen University aims at providing a tool for the quantitative assessment of biotic and abiotic risks for forest ecosystems under the conditions of changing climate. In order to assess the future risks of wind damage the system employs a coupled modelling approach combining the turbulence model SCAlar DIStribution (SCADIS) with the soil-vegetation-atmosphere-transfer (SVAT) model BROOK 90. The present study investigates projections of wind damage in Solling, Germany under climate scenarios A1B and B1, taking into account the windthrow feedbacks-changes of microclimate as a result of tree fall and consequent stabilization or destabilization of a forest stand. The results of the study indicate that in Solling the risk of windthrow for spruce and pine forest stands is likely to increase considerably during the 21st century. The general tendencies indicate that under A1B the probability of damage would be higher than under B1 and that under the same climate and soil conditions the risk for spruce stands would be higher than for pine stands of equal age. The degree of damage and feedback contribution as well as a sign of feedback in each particular case will strongly depend on the particular local or regional combination of climatic and soil factors with tree species, age and structure. For Solling the positive feedback to local climatic forcing is found. The feedback contributes considerably (up to 6% under given conditions) to the projected forest damage and cannot be neglected. Therefore, the adequate projection of future damage probabilities can be performed only with a process-based coupled soil-atmosphere model with corresponding high spatial

  11. Comparison of the Chemical Properties of Forest Soil from the Silesian Beskid, Poland

    Directory of Open Access Journals (Sweden)

    Maria Zołotajkin

    2014-01-01

    Full Text Available There is spruce forests degradation observed in the Silesian Beskid. The aim of the work was the assessment of parameters diversifying organic layers of soils in two forest areas: degraded and healthy spruce forests of Silesian Beskid. 23 soil samples were collected from two fields—14 soil samples from a degraded forest and 9 soil samples from a forest, where pandemic dying of spruce is not observed. Implementation of hierarchical clustering to experimental data analysis allowed drawing a conclusion that the two forest areas vary significantly in terms of content of aluminium extracted with solutions of barium chloride (Alexch, sodium diphosphate (Alpyr, and pHKCl and in the amount of humus in soil.

  12. Radioecological investigations on tree rings of spruce

    International Nuclear Information System (INIS)

    Haas, G.; Mueller, A.

    1995-01-01

    Tree ring analysis contributes essentially to the explanation of physiological and element-specific transport phenomena in trees. After the accident in Chernobyl the behaviour of Cs-134 and Cs-137 in trees is most informative for the prediction of the future development of the distribution of these elements. In this study the uptake and the long term behaviour of Cs-134, Cs-137, Pb-210, Ra-226, Ra-228, K-40, Th-228, Th-230, Th-232, U-234 and U-238 in tree rings of spruce are examined by α- and γ-spectrometry. All samples are dried at 105C and ashed at 450C in a muffle furnace. The distributions found in the tree rings vary for different radionuclides. A soil profile from the spruce stand provides additional information

  13. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  14. Erasing a European biodiversity hot-spot: Open woodlands, veterantrees and mature forests succumb to forestry intensification,succession, and logging in a UNESCO Biosphere Reserve

    Czech Academy of Sciences Publication Activity Database

    Miklín, J.; Čížek, Lukáš

    2014-01-01

    Roč. 22, č. 1 (2014), s. 35-41 ISSN 1617-1381 R&D Projects: GA ČR GAP504/12/1952; GA TA ČR TA02021501 Grant - others:Universita Ostrava(CZ) SGS4/PřF/2012; European Social Fund(CZ) CZ.1.07/2.3.00/20.0064 Institutional support: RVO:60077344 Keywords : forest management * land use/land cover change * lower Morava UNESCO biosphere reserve Subject RIV: EH - Ecology, Behaviour Impact factor: 1.646, year: 2014 http://www.sciencedirect.com/science/article/pii/S1617138113000794

  15. Beyond maturity

    International Nuclear Information System (INIS)

    Tessmer, W.B.

    1990-01-01

    The Nuclear Power Plant Simulator Industry has undergone to decades of evolution in experience, technology and business practices. Link-Miles Simulation Corporation (LMSC) has been contracted to build 68 Full Scope Nuclear Simulators during the 1970's and 1980's. Traditional approaches to design, development and testing have been used to satisfy specifications for initial customer requirements. However, the Industry has matured. All U.S. Nuclear Utilities own, or have under contract, at least one simulator. Other industrial nations have centralized training facilities to satisfy the simulator training needs. The customer of the future is knowledgeable and experienced in the development and service of nuclear simulators. The role of the simulator vendor is changing in order to alter the traditional approach for development. Covenants between the vendors and their customers solidify new complementary roles. This paper presents examples of current simulator project development with recommendations for future endeavors

  16. Current net ecosystem exchange of CO2 in a young mixed forest: any heritage from the previous ecosystem?

    Science.gov (United States)

    Violette, Aurélie; Heinesch, Bernard; Erpicum, Michel; Carnol, Monique; Aubinet, Marc; François, Louis

    2013-04-01

    For 15 years, networks of flux towers have been developed to determine accurate carbon balance with the eddy-covariance method and determine if forests are sink or source of carbon. However, for prediction of the evolution of carbon cycle and climate, major uncertainties remain on the ecosystem respiration (Reco, which includes the respiration of above ground part of trees, roots respiration and mineralization of the soil organic matter), the gross primary productivity (GPP) and their difference, the net ecosystem exchange (NEE) of forests. These uncertainties are consequences of spatial and inter-annual variability, driven by previous and current climatic conditions, as well as by the particular history of the site (management, diseases, etc.). In this study we focus on the carbon cycle in two mixed forests in the Belgian Ardennes. The first site, Vielsalm, is a mature stand mostly composed of beeches (Fagus sylvatica) and douglas fir (Pseudotsuga menziesii) from 80 to 100 years old. The second site, La Robinette, was covered before 1995 with spruces. After an important windfall and a clear cutting, the site was replanted, between 1995 and 2000, with spruces (Piceas abies) and deciduous species (mostly Betula pendula, Aulnus glutinosa and Salix aurita). The challenge here is to highlight how initial conditions can influence the current behavior of the carbon cycle in a growing stand compared to a mature one, where initial conditions are supposed to be forgotten. A modeling approach suits particularly well for sensitivity tests and estimation of the temporal lag between an event and the ecosystem response. We use the forest ecosystem model ASPECTS (Rasse et al., Ecological Modelling 141, 35-52, 2001). This model predicts long-term forest growth by calculating, over time, hourly NEE. It was developed and already validated on the Vielsalm forest. Modelling results are confronted to eddy-covariance data on both sites from 2006 to 2011. The main difference between both

  17. Plant hydraulic strategies and their variability at high latitudes: insights from a southern Canadian boreal forest site

    Science.gov (United States)

    Pappas, C.; Matheny, A. M.; Maillet, J.; Baltzer, J. L.; Stephens, J.; Barr, A.; Black, T. A.; Sonnentag, O.

    2016-12-01

    Boreal forests cover about one third of the world's forested area with a large part of the boreal zone located in Canada. These high-latitude ecosystems respond rapidly to environmental changes. Plant water stress and the resulting drought-induced mortality has been recently hypothesised as a major driver of forest changes in western Canada. Although boreal forests often exhibit low floristic complexity, local scale abiotic heterogeneities may lead to highly variable plant functional traits and thus to diverging plant responses to environmental changes. However, detailed measurements of plant hydraulic strategies and their inter- and intra-specific variability are still lacking for these ecosystems. Here, we quantify plant water use and hydraulic strategies of black spruce (Picea mariana) and larch (Larix laricina), that are widespread in the boreal zone, at a long-term monitoring site located in central Saskatchewan (53.99° N, 105.12° W; elevation 628.94 m a.s.l.). The site is characterized by a mature black spruce overstorey that dominates the landscape with few larch individuals. The ground cover consists mainly of mosses with some peat moss and lichens over a rich soil organic layer. Tree-level sap flux density, measured with Granier-style thermal dissipation probes (N=39), and concurrently recorded radial stem dynamics, measured with high frequency dendrometers (N=13), are used to quantify plant hydraulic functioning during the 2016 growing season. Hydrometeorological measurements, including soil moisture and micrometeorological data, are used to describe environmental constraints in plant water use. Tree-level dynamics are then integrated to the landscape and compared with ecosystem-level evapotranspiration measurements from an adjacent eddy-covariance flux tower. This experimental design allows us to quantify the main environmental drivers that shape plant hydraulic strategies in this southern boreal zone and to provide new insights into the inter- and

  18. Individual variation of sap-flow rate in large pine and spruce trees and stand transpiration: a pilot study at the central NOPEX site

    Science.gov (United States)

    Čermák, J.; Cienciala, E.; Kučera, J.; Lindroth, A.; Bednářová, E.

    1995-06-01

    Transpiration in a mixed old stand of sub-boreal forest in the Norunda region (central Sweden) was estimated on the basis of direct measurement of sap flow rate in 24 large Scots pine and Norway spruce trees in July and August 1993. Sap flow rate was measured using the trunk tissue heat balance method based on internal (electric) heating and sensing of temperature. Transpiration was only 0.7 mm day -1 in a relatively dry period in July (i.e. about 20% of potential evaporation) and substantially higher after a rainy period in August. The error of the estimates of transpiration was higher during a dry period (about 13% and 22% in pine and spruce, respectively) and significantly lower (about 9% in both species) during a period of sufficient water supply. Shallow-rooted spruce trees responded much faster to precipitation than deeply rooted pines.

  19. Modelling Forest Water Consumption in The Netherlands

    NARCIS (Netherlands)

    Dolman, A.J.; Nonhebel, S.

    1988-01-01

    The water consumption of oak, beech, spruce and pine forest is predicted from routinely measured meteorological data for five locations in the Netherlands. Differences in water consumption are found to be primarily a result of differences in interception loss. Predicted interception loss was found

  20. Migration and bioavailability of 137Cs in forest soil of southern Germany

    International Nuclear Information System (INIS)

    Konopleva, I.; Klemt, E.; Konoplev, A.; Zibold, G.

    2009-01-01

    To give a quantitative description of the radiocaesium soil-plant transfer for fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus), physical and chemical properties of soils in spruce and mixed forest stands were investigated. Of special interest was the selective sorption of radiocaesium, which was determined by measuring the Radiocaesium Interception Potential (RIP). Forest soil and plants were taken at 10 locations of the Altdorfer Wald (5 sites in spruce forest and 5 sites in mixed forest). It was found that the bioavailability of radiocaesium in spruce forest was on average seven times higher than in mixed forest. It was shown that important factors determining the bioavailability of radiocaesium in forest soil were its exchangeability and the radiocaesium interception potential (RIP) of the soil. Low potassium concentration in soil solution of forest soils favors radiocaesium soil-plant transfer. Ammonium in forest soils plays an even more important role than potassium as a mobilizer of radiocaesium. The availability factor - a function of RIP, exchangeability and cationic composition of soil solution - characterized reliably the soil-plant transfer in both spruce and mixed forest. For highly organic soils in coniferous forest, radiocaesium sorption at regular exchange sites should be taken into account when its bioavailability is considered

  1. Application of GIS to Empirical Windthrow Risk Model in Mountain Forested Landscapes

    Directory of Open Access Journals (Sweden)

    Lukas Krejci

    2018-02-01

    Full Text Available Norway spruce dominates mountain forests in Europe. Natural variations in the mountainous coniferous forests are strongly influenced by all the main components of forest and landscape dynamics: species diversity, the structure of forest stands, nutrient cycling, carbon storage, and other ecosystem services. This paper deals with an empirical windthrow risk model based on the integration of logistic regression into GIS to assess forest vulnerability to wind-disturbance in the mountain spruce forests of Šumava National Park (Czech Republic. It is an area where forest management has been the focus of international discussions by conservationists, forest managers, and stakeholders. The authors developed the empirical windthrow risk model, which involves designing an optimized data structure containing dependent and independent variables entering logistic regression. The results from the model, visualized in the form of map outputs, outline the probability of risk to forest stands from wind in the examined territory of the national park. Such an application of the empirical windthrow risk model could be used as a decision support tool for the mountain spruce forests in a study area. Future development of these models could be useful for other protected European mountain forests dominated by Norway spruce.

  2. Migration and bioavailability of {sup 137}Cs in forest soil of southern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Konopleva, I.; Klemt, E. [Hochschule Ravensburg-Weingarten, University of Applied Sciences, 88250 Weingarten (Germany); Konoplev, A. [Scientific Production Association ' TYPHOON' , Obninsk (Russian Federation); Zibold, G. [Hochschule Ravensburg-Weingarten, University of Applied Sciences, 88250 Weingarten (Germany)], E-mail: zibold@hs-weingarten.de

    2009-04-15

    To give a quantitative description of the radiocaesium soil-plant transfer for fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus), physical and chemical properties of soils in spruce and mixed forest stands were investigated. Of special interest was the selective sorption of radiocaesium, which was determined by measuring the Radiocaesium Interception Potential (RIP). Forest soil and plants were taken at 10 locations of the Altdorfer Wald (5 sites in spruce forest and 5 sites in mixed forest). It was found that the bioavailability of radiocaesium in spruce forest was on average seven times higher than in mixed forest. It was shown that important factors determining the bioavailability of radiocaesium in forest soil were its exchangeability and the radiocaesium interception potential (RIP) of the soil. Low potassium concentration in soil solution of forest soils favors radiocaesium soil-plant transfer. Ammonium in forest soils plays an even more important role than potassium as a mobilizer of radiocaesium. The availability factor - a function of RIP, exchangeability and cationic composition of soil solution - characterized reliably the soil-plant transfer in both spruce and mixed forest. For highly organic soils in coniferous forest, radiocaesium sorption at regular exchange sites should be taken into account when its bioavailability is considered.

  3. Soil surface CO2 flux in a boreal black spruce fire chronosequence

    Science.gov (United States)

    Wang, Chuankuan; Bond-Lamberty, Ben; Gower, Stith T.

    2003-02-01

    Understanding the effects of wildfire on the carbon (C) cycle of boreal forests is essential to quantifying the role of boreal forests in the global carbon cycle. Soil surface CO2 flux (Rs), the second largest C flux in boreal forests, is directly and indirectly affected by fire and is hypothesized to change during forest succession following fire. The overall objective of this study was to measure and model Rs for a black spruce (Picea mariana [Mill.] BSP) postfire chronosequence in northern Manitoba, Canada. The experiment design was a nested factorial that included two soil drainage classes (well and poorly drained) × seven postfire aged stands. Specific objectives were (1) to quantify the relationship between Rs and soil temperature for different aged boreal black spruce forests in well-drained and poorly drained soil conditions, (2) to examine Rs dynamics along postfire successional stands, and (3) to estimate annual soil surface CO2 flux for these ecosystems. Soil surface CO2 flux was significantly affected by soil drainage class (p = 0.014) and stand age (p = 0.006). Soil surface CO2 flux was positively correlated to soil temperature (R2 = 0.78, p aged stand combination. Soil surface CO2 flux was significantly greater at the well-drained than the poorly drained stands (p = 0.007) during growing season. Annual soil surface CO2 flux for the 1998, 1995, 1989, 1981, 1964, 1930, and 1870 burned stands averaged 226, 412, 357, 413, 350, 274, and 244 g C m-2 yr-1 in the well-drained stands and 146, 380, 300, 303, 256, 233, and 264 g C m-2 yr-1 in the poorly drained stands. Soil surface CO2 flux during the winter (from 1 November to 30 April) comprised from 5 to 19% of the total annual Rs. We speculate that the smaller soil surface CO2 flux in the recently burned than the older stands is mainly caused by decreased root respiration.

  4. DAMPAK PEMBANGUNAN HUTAN TANAMAN INDUSTRI Acacia crassicarpa DI LAHAN GAMBUT TERHADAP TINGKAT KEMATANGAN DAN LAJU PENURUNAN PERMUKAAN TANAH (The Impact of Development of Industrial Plantation Forest Acacia crassicarpa in Peatland Towards the Maturity

    Directory of Open Access Journals (Sweden)

    Yunita Lisnawati

    2015-07-01

    Full Text Available ABSTRAK Pembangunan hutan tanaman di lahan gambut tidak terlepas dari sorotan isu negatif lingkungan terkait dengan penurunan kedalaman muka air tanah, sehingga terjadi perubahan ekosistem asli. Kegiatan reklamasi lahan untuk HTI Acacia crassicarpa dalam jangka panjang disinyalir akan menimbulkan dampak negatif terhadap perubahan karakteristik tanah gambutnya seperti tingkat kematangan dan laju penurunan permukaan tanah gambut (subsiden. Kajian mengenai dampak pembangunan HTI di lahan gambut terhadap tingkat kematangan dan laju subsiden perlu dilakukan untuk memberikan informasi mengenai kondisi exsisting daya dukung lahannya. Penelitian ini bertujuan untuk mengevaluasi tingkat kematangan gambut baik secara vertikal (berdasarkan kedalaman gambut maupun secara horizontal (berdasarkan jarak dari bibir kanal dan mengetahui laju subsiden sebagai dampak dari reklamasi lahan gambut menjadi HTI A. crassicarpa. Penelitian dilakukan di PT AA, Distrik Rasau Kuning, Kabupaten Siak, Riau. Plot penelitian ditempatkan dalam satu transek sepanjang 100 m yang dibuat tegak lurus dengan kanal tersier, terdapat 12 plot dan dalam satu transek terdapat 3 titik pengamatan sehingga total titik pengamatan adalah 36 titik. Parameter yang diamati adalah dinamika kedalaman muka air tanah, nilai kadar serat tanah gambut dan laju subsiden. Hasil penelitian menunjukkan bahwa dampak perubahan kedalaman muka air tanah gambut di lokasi penelitian hanya mempengaruhi tingkat kematangan gambut pada kedalaman kurang dari 2 m, sedangkan jarak kanal tersier sebesar 125 m tidak berpengaruh secara nyata terhadap tingkat kematangan gambut. Pada kedalaman kurang dari 2 m tingkat kematangan gambut lebih tinggi dibandingkan dengan lapisan di bawahnya. Pembangunan HTI A. crassicarpa di lokasi penelitian menyebabkan laju subsiden sebesar rata-rata 5,5 cm/tahun.  ABSTRACT The establishment of forest on peat areas is insepatable from the glare of the negative environmental issues associated

  5. Some observations on age relationships in spruce-fir regeneration

    Science.gov (United States)

    Barton M. Blum

    1973-01-01

    Measurement of the ages of seedlings of balsam fir (Abies balsamea (L) Mill.), red spruce (Picea rubens Sarg.), and white spruce (Picea glauca (Moench) Voss) 15 years after the first harvest of a two-cut shelterwood operation revealed that very few potential crop-tree seedlings in the sample occurred as advance...

  6. Ethanol exposure can inhibit red spruce ( Picea rubens ) seed germination

    Science.gov (United States)

    John R. Butnor; Brittany M. Verrico; Victor Vankus; Stephen R. Keller

    2018-01-01

    Flotation of seeds in solvents is a common means of separating unfilled and filled seeds. While a few protocols for processing red spruce (Picea rubens) seeds recommend ethanol flotation, delayed and reduced germination have been reported. We conducted an ethanol bioassay on seeds previously stored at -20°C to quantify the concentration required to separate red spruce...

  7. Warming drives a front of white spruce establishment near western treeline, Alaska.

    Science.gov (United States)

    Miller, Amy E; Wilson, Tammy L; Sherriff, Rosemary L; Walton, James

    2017-12-01

    Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, the effects of warming on seedling recruitment have received little attention, in spite of forecasted forest expansion. Here, we used stand structure and environmental data from 95 white spruce (Picea glauca) plots sampled across a longitudinal gradient in southwest Alaska to explore factors influencing spruce establishment and recruitment near western treeline. We used total counts of live seedlings, saplings, and trees, representing five life stages, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance, using current abundance distributions as a surrogate for climate conditions in the past. We used generalized linear models to test the null hypothesis that conditions favorable for recruitment were similar along the environmental gradient represented by longitude, by exploring relationships between per-plot counts of each life stage and the covariates hypothesized to affect abundance. We also examined the relationship between growing degree days (GDD) and seedling establishment over a period of three decades using tree-ring chronologies obtained from cores taken at a subset of our sites (n = 30). Our results indicated that seedling, sapling, and tree abundance were positively correlated with temperature across the study area. The response to longitude was mixed, with earlier life stages (seedlings, saplings) most abundant at the western end of the gradient, and later life stages (trees) most abundant to the east. The differential relationship between longitude and life-stage abundance suggests a moving front of white spruce establishment through time, driven by changes in environmental conditions near the species' western range limit. Likewise, we found a positive relationship between periods of seedling establishment and GDD, suggesting that longer summers and/or greater heat accumulation might enhance establishment

  8. Spruce colonization at treeline: where do those seeds come from?

    Science.gov (United States)

    Piotti, A; Leonardi, S; Piovani, P; Scalfi, M; Menozzi, P

    2009-08-01

    At treeline, selection by harsh environmental conditions sets an upward limit to arboreal vegetation. Increasing temperatures and the decline of traditional animal raising have favoured an upward shift of treeline in the last decades. These circumstances create a unique opportunity to study the balance of the main forces (selection and gene flow) that drive tree migration. We conducted a parentage analysis sampling and genotyping with five microsatellite markers in all Norway spruce individuals (342 juveniles and 23 adults) found in a recently colonized treeline area (Paneveggio forest, Eastern Alps, Italy). Our goal was to evaluate local reproductive success versus gene flow from the outside. We were able to identify both parents among local adults for only 11.1% of the juveniles. In the gamete pool we sampled, two-thirds were not produced locally. Effective seed dispersal distance distribution was characterized by a peak far from the seed source (mean 344.66 m+/-191.02 s.d.). Reproductive success was skewed, with six local adults that generated almost two-thirds (62.4%) of juveniles with local parents. Our findings indicate that, although a few local adults seem to play an important role in the colonization process at treeline, large levels of gene flow from outside were maintained, suggesting that the potential advantages of local adults (such as local adaptation, proximity to the colonization area, phenological synchrony) did not prevent a large gamete immigration.

  9. Ants accelerate succession from mountain grassland towards spruce forest

    Czech Academy of Sciences Publication Activity Database

    Vlasáková, B.; Raabová, J.; Kyncl, T.; Dostál, Petr; Kovářová, Marcela; Kovář, P.; Herben, Tomáš

    2009-01-01

    Roč. 20, č. 4 (2009), s. 577-587 ISSN 1100-9233 Institutional research plan: CEZ:AV0Z60050516 Keywords : anthills * chronosequence * disturbance Subject RIV: EF - Botanics Impact factor: 2.376, year: 2009

  10. Long-term Water Use Efficiency of Young Spruce Forest

    Czech Academy of Sciences Publication Activity Database

    Slípková, Romana; Pokorný, Radek

    2012-01-01

    Roč. 951, č. 1 (2012), s. 293-300 ISSN 0567-7572. [International Workshop On Sap Flow /8./. Volterra, 08.05.2011-12.05.2011] R&D Projects: GA MŽP(CZ) SP/2D1/70/08; GA MŽP(CZ) SP/2D1/93/07; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : transpiration * total aboveground biomass increment * growth dynamic Subject RIV: EH - Ecology, Behaviour

  11. Canopy position affects photosynthetic adjustments to long-term elevated CO{sub 2} concentration (FACE) in aging needles in a mature Pinus taeda forest

    Energy Technology Data Exchange (ETDEWEB)

    Crous, K. Y.; Ellsworth, D. S. [University of Michigan, School of Natural Resources and Environment, Ann Arbor, MI (United States)

    2004-09-01

    Results of an assessment of the long-term effects of exposure to elevated carbon dioxide in free-air enrichment (FACE) on two age classes of pine needles in the upper and lower canopy of a pine forest in North Carolina are discussed. The observations were made during the second through sixth year of exposure. A significant response was observed in 60 per cent of all age classes and canopy locations. Evidence of concurrent down-regulation of Rubisco and electron transport capacity in upper canopy sunlit leaves was noted beyond the sixth year. No such effect was seen in the lower canopy. Carboxylation capacity and electron transport capacity in the upper canopy was down-regulated by 17-20 per cent in one year-old needles, but this was significant across sampling years only for electron transport capacity. It is suggested that a reduction in photosynthetic capacity in aging conifer needles at the canopy top may have significant consequences for canopy carbon balance and global carbon sinks because a major proportion of the annual carbon balance of these conifers is contributed by one-year old sunlit needles. 45 refs., 3 tabs., 4 figs.

  12. Distinct genecological patterns in seedlings of Norway spruce and silver fir from a mountainous landscape.

    Science.gov (United States)

    Frank, Aline; Sperisen, Christoph; Howe, Glenn Thomas; Brang, Peter; Walthert, Lorenz; St Clair, John Bradley; Heiri, Caroline

    2017-01-01

    Understanding the genecology of forest trees is critical for gene conservation, for predicting the effects of climate change and climate change adaptation, and for successful reforestation. Although common genecological patterns have emerged, species-specific details are also important. Which species are most vulnerable to climate change? Which are the most important adaptive traits and environmental drivers of natural selection? Even though species have been classified as adaptive specialists vs. adaptive generalists, large-scale studies comparing different species in the same experiment are rare. We studied the genecology of Norway spruce (Picea abies) and silver fir (Abies alba), two co-occurring but ecologically distinct European conifers in Central Europe. For each species, we collected seed from more than 90 populations across Switzerland, established a seedling common-garden test, and developed genecological models that associate population variation in seedling growth and phenology to climate, soil properties, and site water balance. Population differentiation and associations between seedling traits and environmental variables were much stronger for Norway spruce than for silver fir, and stronger for seedling height growth than for bud phenology. In Norway spruce, height growth and second flushing were strongly associated with temperature and elevation, with seedlings from the lowlands being taller and more prone to second flush than seedlings from the Alps. In silver fir, height growth was more weakly associated with temperature and elevation, but also associated with water availability. Soil characteristics explained little population variation in both species. We conclude that Norway spruce has become an adaptive specialist because trade-offs between rapid juvenile growth and frost avoidance have subjected it to strong diversifying natural selection based on temperature. In contrast, because silver fir has a more conservative growth habit, it has

  13. High rates of solar radiation - an important natural stress factor of the photosynthetic activity of mountainous norway spruce stands

    International Nuclear Information System (INIS)

    Sprtova, M.; Marek, M.V.

    1996-01-01

    Photosynthetic activity can be regarded as the basis of biomass productivity and vitality of forest trees, respectively. Moreover, this activity is under the strong influence of environment. Excess of photosynthetically active radiation (PhAR) can be a harmful factor of environment which is the reason of photoinhibition. Photoinhibition is demonstrated by a decrease of photosynthetic rate. An analysis of the influence of PhAR excess on function of the assimilatory apparatus of Norway spruce during summer days was done. The strong influence of PhAR excess on values of parameters of photosynthesis reflecting changes in the level of quanta capture and electron transport chain was observed. The comprehensive description of the method of chlorophyll a is given. Excess of PhAR caused rapid changes of assimilatory apparatus function and thus this PhAR excess can be regarded as a significant stress of productional activity of Norway spruce stands under field conditions

  14. Size-dependence of tree growth response to drought for Norway spruce and European beech individuals in monospecific and mixed-species stands.

    Science.gov (United States)

    Ding, H; Pretzsch, H; Schütze, G; Rötzer, T

    2017-09-01

    Climate anomalies have resulted in changing forest productivity, increasing tree mortality in Central and Southern Europe. This has resulted in more severe and frequent ecological disturbances to forest stands. This study analysed the size-dependence of growth response to drought years based on 384 tree individuals of Norway spruce [Picea abies (L.) Karst.] and European beech [Fagus sylvatica ([L.)] in Bavaria, Germany. Samples were collected in both monospecific and mixed-species stands. To quantify the growth response to drought stress, indices for basal area increment, resistance, recovery and resilience were calculated from tree ring measurements of increment cores. Linear mixed models were developed to estimate the influence of drought periods. The results show that ageing-related growth decline is significant in drought years. Drought resilience and resistance decrease significantly with growth size among Norway spruce individuals. Evidence is also provided for robustness in the resilience capacity of European beech during drought stress. Spruce benefits from species mixing with deciduous beech, with over-yielding spruce in pure stands. The importance of the influence of size-dependence within tree growth studies during disturbances is highlighted and should be considered in future studies of disturbances, including drought. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  15. Using a standing-tree acoustic tool to identify forest stands for the production of mechanically-graded lumber.

    Science.gov (United States)

    Paradis, Normand; Auty, David; Carter, Peter; Achim, Alexis

    2013-03-12

    This study investigates how the use of a Hitman ST300 acoustic sensor can help identify the best forest stands to be used as supply sources for the production of Machine Stress-Rated (MSR) lumber. Using two piezoelectric sensors, the ST300 measures the velocity of a mechanical wave induced in a standing tree. Measurements were made on 333 black spruce (Picea mariana (Mill.) BSP) trees from the North Shore region, Quebec (Canada) selected across a range of locations and along a chronosequence of elapsed time since the last fire (TSF). Logs were cut from a subsample of 39 trees, and sawn into 77 pieces of 38 mm × 89 mm cross-section before undergoing mechanical testing according to ASTM standard D-4761. A linear regression model was developed to predict the static modulus of elasticity of lumber using tree acoustic velocity and stem diameter at 1.3 m above ground level (R2 = 0.41). Results suggest that, at a regional level, 92% of the black spruce trees meet the requirements of MSR grade 1650Fb-1.5E, whilst 64% and 34% meet the 2100Fb-1.8E and 2400Fb-2.0E, respectively. Mature stands with a TSF < 150 years had 11 and 18% more boards in the latter two categories, respectively, and therefore represented the best supply source for MSR lumber.

  16. Vegetation types and forest productivity, west part of Syncrude's Lease 17, Alberta. Environmental Research Monography 1977-6. [Tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, E B; Levinsohn, A G

    1977-01-01

    The vegetation that existed in August 1977 on the western half of Syncrude's Lease 17 near Fort McMurray, Alberta is described. Eight vegetation types were identified and are mapped at a scale if 1 : 24,000. Black Spruce--Labrador Tea was the dominant vegetation type, making up 35.0% of the 9250 hectare study area. The second most abundant vegetation type was Aspen--White Spruce (26.0%) and the third was White Spruce--Aspen (18.0%). The remaining 21.0% of the area was occupied by the Aspen--Birch vegetation type (7.5%), Balsam Poplar--Alder (6.0%) along the McKay River, Sedge--Reed Grass (4.0%) mainly around bodies of standing water created by beaver dams, Willow--Reed Grass (3.0%) along stream courses, and Black Spruce--Feathermoss (0.5%). The White Spruce--Aspen type is best developed in the southern part of the lease. It is the only vegetation type that contains some white spruce stands approaching the present lower limits of merchantable forest in Alberta. The Aspen--White Spruce type was less productive. In terms of mean annual increment and site index, the two vegetation types with the greatest potential for fibre production (White Spruce--Aspen and Aspen--White Spruce types) are average or below average productivity when compared to data from similar stands elsewhere in Alberta and Saskatchewan.

  17. The impact of small terrestrial mammals on beech (Fagus sylvatica plantations in spruce monoculture

    Directory of Open Access Journals (Sweden)

    Luboš Purchart

    2007-01-01

    Full Text Available Little is known about the impact of small terrestrial mammals on forest regeneration as yet. In order to determine the level of small rodent impact on artificial forest regeneration, 508 saplings have been researched in a spruce monoculture in the Drahany Uplands. With the objective to hone the interpretation of the data, small terrestrial rodents were trapped to help determine species spectrum. The occurrence of Apodemus flavicollis, Clethrionomys glareolus and Sorex araneus was verified. In 52 cases damage to the trunk caused by small rodents was monitored (10.1% of all saplings. 8 specimens (1.6% had their branches nibbled and 9 saplings (1.8% had tips of branches or trunk tops browsed. Browsing by Lepus europaeus – 423 (83.3% of all damaged specimens was significant.

  18. Pollutant exclusion experiments on spruce at the Edelmannshof site. Results of physiological and biochemical investigations

    International Nuclear Information System (INIS)

    Arndt; Bauer; Bourgois

    1993-01-01

    From 1987-1992 within the framework of a multidisciplinary approach extensive studies of physiological and biochemical parameters of spruce trees (Picea abies L. Karst.) growing on natural site in a forest decline area (Schwaebisch-Fraenkischer Wald) north-west of the conurbation Stuttgart were carried out. This pollutant-exclusion experiment was a further part of a threepart research program including field observations and defined pollutant experiments with young forest trees in modelecosystems. The results show, that also low concentrations of air pollutants cause effects in plant metabolism before the occurence of visible symptoms. The pollutant effects caused specially by ozone have to be linked to climatic factors such as drought which occured in the last years. In a final view some factors influencing the long-term project Edelmannshof are shown. Ultimately possible key-reactions for bioindication methods on the synecological level are presented. (orig.) [de

  19. Comparison of riparian and upland forest stand structure and fuel loads in beetle infested watersheds, southern Rocky Mountains

    Science.gov (United States)

    Kathleen A. Dwire; Robert Hubbard; Roberto Bazan

    2015-01-01

    Extensive outbreaks of mountain pine beetle (MPB), spruce beetle (SB), and other insects are altering forest stand structure throughout western North America, and thereby contributing to the heterogeneity of fuel distribution. In forested watersheds, conifer-dominated riparian forests frequently occur as narrow linear features in the landscape mosaic and contribute to...

  20. Age-related effects on leaf area/sapwood area relationships, canopy transpiration and carbon gain of Norway spruce stands (Picea abies) in the Fichtelgebirge, Germany.

    Science.gov (United States)

    Köstner, B; Falge, E; Tenhunen, J D

    2002-06-01

    Stand age is an important structural determinant of canopy transpiration (E(c)) and carbon gain. Another more functional parameter of forest structure is the leaf area/sapwood area relationship, A(L)/A(S), which changes with site conditions and has been used to estimate leaf area index of forest canopies. The interpretation of age-related changes in A(L)/A(S) and the question of how A(L)/A(S) is related to forest functions are of current interest because they may help to explain forest canopy fluxes and growth. We conducted studies in mature stands of Picea abies (L.) Karst. varying in age from 40 to 140 years, in tree density from 1680 to 320 trees ha(-1), and in tree height from 15 to 30 m. Structural parameters were measured by biomass harvests of individual trees and stand biometry. We estimated E(c) from scaled-up xylem sap flux of trees, and canopy-level fluxes were predicted by a three-dimensional microclimate and gas exchange model (STANDFLUX). In contrast to pine species, A(L)/A(S) of P. abies increased with stand age from 0.26 to 0.48 m(2) cm(-2). Agreement between E(c) derived from scaled-up sap flux and modeled canopy transpiration was obtained with the same parameterization of needle physiology independent of stand age. Reduced light interception per leaf area and, as a consequence, reductions in net canopy photosynthesis (A(c)), canopy conductance (g(c)) and E(c) were predicted by the model in the older stands. Seasonal water-use efficiency (WUE = A(c)/E(c)), derived from scaled-up sap flux and stem growth as well as from model simulation, declined with increasing A(L)/A(S) and stand age. Based on the different behavior of age-related A(L)/A(S) in Norway spruce stands compared with other tree species, we conclude that WUE rather than A(L)/A(S) could represent a common age-related property of all species. We also conclude that, in addition to hydraulic limitations reducing carbon gain in old stands, a functional change in A(L)/A(S) that is related to

  1. Sources of Respired Carbon in a Northern Minnesota Ombrotrophic Spruce Bog: Preliminary 14C Results from the SPRUCE Site.

    Science.gov (United States)

    Guilderson, T. P.; McNicol, G.; Machin, A.; Hanson, P. J.; McFarlane, K. J.; Osuna, J. L.; Pett-Ridge, J.; Singleton, M. J.

    2014-12-01

    A significant uncertainty in future land-surface carbon budgets is the response of wetlands to climate change. A corollary and related question is the future net climate (radiative) forcing impact from wetlands. Active wetlands emit both CO2 and CH4 to the atmosphere. CH4 is, over a few decades, a much more potent greenhouse gas than CO2. CO2 has a longer atmospheric lifetime and a longer 'tail' to its radiative influence. Whether wetlands are a net source or sink of atmospheric carbon under future climate change will depend on ecosystem response to rising temperatures and elevated CO2. The largest uncertainty in future wetland C-budgets, and their climate forcing is the stability of the large below-ground carbon stocks, often in the form of peat, and the partitioning of CO2 and CH4 released via ecosystem respiration. In advance of a long-term experimental warming and elevated CO2 manipulation at the DOE Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) site in the Marcell Experimental Forest, we have characterized the source of respired carbon used for both the production of CO2 and CH4. Samples were collected in early June, late July, and will be collected in early September from three large (~1.1 m2, ~0.5m3) chambers from the control plot, and two of the experimental plots selected for heating (+9°C, +4.5°C). Early June fluxes from the three chambers were ~5500 mgC-m-2-d-1 and ~16 mgC-m-2-d-1 for CO2 and CH4 respectively. Radiocarbon analysis of CO2 and CH4 indicate that the source for the respired carbon is for the most part recent, with most 14C values between 30 and 40‰ - i.e., carbon that was photosynthetically fixed in the last few years. In concert with rising air and ground temperatures fluxes in late July increased to ~6500 mgC-m-2-d-1 and ~86 mgC-m-2-d-1. Although deep-heating was initiated in mid to late June we hypothesize that the July respiration signal is dominated by the regular seasonal cycle of natural warming

  2. Depression of belowground respiration is more pronounced than enhancement of photosynthesis during the first year after nitrogen fertilization of a mature Pacific Northwest Douglas-fir forest

    Science.gov (United States)

    Chen, B.; Black, T. A.; Jassal, R.; Nesic, Z.; Bruemmer, C.

    2008-05-01

    Nitrogen (N) additions to forest have shown variable effects on both respiration and photosynthesis. With increasing rates of anthropogenic N deposition, there is a strong need to understand the ecosystem response to N inputs. We investigated how N fertilization affects the ecosystem carbon (C) balance of a 57-year-old coast Douglas-fir stand in British Columbia, Canada, based on eddy-covariance (EC) and soil-chamber (fertilized and control plots) measurements and process-based modeling. The stand was fertilized by helicopter with urea at 200 kg N ha-1 in January 2007. A land surface model (Ecosystem Atmosphere Simulation Scheme, EASS) was combined with an ecosystem model (Boreal Ecosystem Productivity Simulator, BEPS) and a coupled C and N subroutine was incorporated into the integrated EASS-BEPS model in this study. This half-hourly time step model was run continuously for the period from 2001 to 2007 in two scenarios: with and without fertilization. Modeled C fluxes without fertilization [net ecosystem productivity (NEP), gross primary productivity (GPP), ecosystem respiration (Re) and belowground respiration (Rs)] agreed well with EC and soil chamber measurements over diurnal, seasonal and annual time scales for 2001 to 2006; while simulated NEP, GPP, Re and Rs with fertilization reasonably followed EC and chamber measurements in 2007 (545 vs. 520, 2163 vs. 2155, 1618 vs. 1635, and 920 vs. 906 g C m-2 yr-1, respectively). Comparison of EC-determined C fluxes in 2007 with model simulations without fertilization suggests that annual Re decreased by 6.7% (1635 vs. 1752 g C m-2), gross primary productivity (GPP) increased by 6.8% (2155 vs. 2017 g C m-2), and annual NEP increased by 96.2% (520 vs. 265 g C m-2) due to fertilization. The modeled reduction in Rs (9.6%, comparing modeled values without and with fertilization: 1008 vs. 920 g C m-2 yr-1) is consistent with that measured using the soil chambers (~11.5%, comparing CO2 effluxes from control and fertilized

  3. Macro-nutrientes no lençol freático em Floresta Intacta, Floresta de Manejo e Pastagem no norte de Mato Grosso Macro-nutrients in the water sheet in Mature Forest, Management Forest and Pasture in the north of Mato Grosso

    Directory of Open Access Journals (Sweden)

    Nara Luisa Reis de Andrade

    2008-12-01

    Full Text Available A remoção de uma cobertura florestal e sua substituição por outras formas de uso do solo tem sido uma constante no norte do estado de Mato Grosso podendo alterar os ciclos hidrológicos e biogeoquímicos dos ecossistemas. Neste contexto, o presente trabalho visou identificar a variação do fósforo e nitrogênio das águas do lençol freático em áreas de Floresta de Transição madura e intacta (Floresta Intacta, Floresta de Transição Manejada (Floresta Manejada e Pastagem localizadas no norte de Mato Grosso. Foram realizadas mensalmente medidas do nível do lençol freático, de coletas de amostras de água para análises físico-químicas e medições de precipitação e temperatura do ar, no período de janeiro/2005 a novembro/2006. Verificou-se uma sazonalidade na precipitação e na temperatura do ar. No período de estiagem as águas do lençol freático apresentaram maiores teores de nitrogênio e de fósforo total nas três áreas em estudo. Os maiores valores de nitrogênio e fósforo foram detectados nos ecossistemas florestais (Florestas Intacta e Manejada como indicativo da função da cobertura vegetal na ciclagem dos nutrientes.Forest removal for other land uses has been a constant in the north of Mato Grosso and can alter the hydrological and biochemical cycles. In this context, the present work aims to identify the variation of phosphorus and nitrogen in the water sheet in areas of Mature Forest, Management Forest and Pasture in the north of Mato Grosso. The water level was measured monthly and water samples for analysis were collected monthly from January/2005 to November/2006. We verified the precipitation and the air temperature seasonality, and in the dry season the quality of the water sheet presented greater values of total phosphorus and total Kjeldhal nitrogen in the studied areas. The phosphorus and nitrogen presented greater values in forest ecosystems (Forest and Management Forest as indicative of the function

  4. Woodland: dynamics of average diameters of coniferous tree stands of the principal forest types

    Directory of Open Access Journals (Sweden)

    R. A. Ziganshin

    2016-08-01

    Full Text Available The analysis of age dynamics of average diameters of deciduous tree stands of different forest types at Highland Khamar-Daban (natural woodland in South-East Baikal Lake region has been done. The aggregate data of average tree, the analysis of age dynamics of average diameters of a deciduous tree stands of stand diameters by age classes, as well as tree stand current periodic and overall average increment are presented and discussed in the paper. Forest management appraisal is done. The most representative forest types have been selected to be analyzed. There were nine of them including three Siberian stone pine Pinus sibirica Du Tour stands, three Siberian fir Abies sibirica Ledeb. stands, one Siberian spruce Picea obovata Ledeb. stand, and two dwarf Siberian pine Pinus pumila (Pallas Regel stands. The whole high-altitude range of mountain taiga has been evaluated. Mathematical and statistic indicators have been calculated for every forest type. Stone pine stands are the largest. Dynamics of mean diameters of forest stands have been examined by dominant species for every forest type. Quite a number of interesting facts have been elicited. Generally, all species have maximal values of periodic annual increment that is typical for young stands, but further decrease of increment is going on differently and connects to the different lifetime of wood species. It is curious that annual increment of the dwarf Siberian pine stands almost does not decrease with aging. As for mean annual increment, it is more stable than periodic annual increment. From the fifth age class (age of stand approaching maturity mean annual increment of cedar stands varies from 0.20 to 0.24 cm per year; from 0.12–0.15 to 0.18–0.21 cm per year – in fir stands; from 0.18 to 0.24 cm per year – in spruce stands; and from 0.02–0.03 to 0.05–0.06 cm per year – in draft pine stands. Mean annual increment of dwarf Siberian pine increases with aging and increment of other

  5. Contribution of black spruce (Picea mariana) transpiration to growing season evapotranspiration in a subarctic discontinuous permafrost peatland complex

    Science.gov (United States)

    Helbig, M.; Warren, R. K.; Pappas, C.; Sonnentag, O.; Berg, A. A.; Chasmer, L.; Baltzer, J. L.; Quinton, W. L.; Patankar, R.

    2016-12-01

    Partitioning the components of evapotranspiration (ET), evaporation and transpiration, has been increasingly important for the better understanding and modeling of carbon, water, and energy dynamics, and for reliable water resources quantification and management. However, disentangling its individual processes remains highly uncertain. Here, we quantify the contribution of black spruce transpiration, the dominant overstory, to ET of a boreal forest-wetland landscape in the southern Taiga Plains. In these ecosystems, thawing permafrost induces rapid landscape change, whereby permafrost-supported forested plateaus are transformed into bogs or fens (wetlands), resulting in tree mortality. Using historical and projected rates of forest-wetland changes, we assess how the contribution of black spruce transpiration to landscape ET might be altered with continued permafrost loss, and quantify the resulting water balance changes. We use two nested eddy covariance flux towers and a footprint model to quantify ET over the entire landscape. Sap flux density of black spruce is measured using the heat ratio method during the 2013 (n=22) and 2014 (n=3) growing seasons, and is used to estimate tree-level transpiration. Allometric relations between tree height, diameter at breast height and sapwood area are derived to upscale tree-level transpiration to overstory transpiration within the eddy covariance footprint. Black spruce transpiration accounts for <10% of total landscape ET. The largest daily contribution of overstory transpiration to landscape ET is observed shortly after the landscape becomes snow-free, continually decreasing throughout the progression of the growing season. Total transpiration is notably lower in 2014 (2.34 mm) than 2013 (2.83 mm) over the same 40-day period, corresponding to 3% of cumulative landscape ET in both years. This difference is likely due to the antecedent moisture conditions, where the 2014 growing season was proceeded by lower than average

  6. Antioxidant defences of Norway spruce bark against bark beetles and its associated blue-stain fungus

    Directory of Open Access Journals (Sweden)

    Felicijan Mateja

    2015-12-01

    Full Text Available Bark beetles and their fungal associates are integral parts of forest ecosystems, the European spruce bark beetle (Ips typographus Linnaeus, 1758 and the associated pathogenic blue stain fungus Ceratocystis polonica (SIEM. C. MOREAU, are the most devastating pests regarding Norway spruce [Picea abies (L. H. KARST.]. Bark beetles commonly inhabit weakened and felled trees as well as vital trees. They cause physiological disorders in trees by destroying a phloem and cambium or interrupt the transpiration -ow in the xylem. Conifers have a wide range of effective defence mechanisms that are based on the inner bark anatomy and physiological state of the tree. The basic function of bark defences is to protect the nutrient-and energy-rich phloem, the vital meristematic region of the vascular cambium, and the transpiration -ow in the sapwood. The main area of defence mechanisms is secondary phloem, which is physically and chemically protected by polyphenolic parenchyma (PP cells, sclerenchyma, calcium oxalate crystals and resin ducts. Conifer trunk pest resistance includes constitutive, inducible defences and acquired resistance. Both constitutive and inducible defences may deter beetle invasion, impede fungal growth and close entrance wounds. During a successful attack, systemic acquired resistance (SAR becomes effective and represents a third defence strategy. It gradually develops throughout the plant and provides a systemic change within the whole tree’s metabolism, which is maintained over a longer period of time. The broad range of defence mechanisms that contribute to the activation and utilisation of SAR, includes antioxidants and antioxidant enzymes, which are generally linked to the actions of reactive oxygen species (ROS. The presented review discusses the current knowledge on the antioxidant defence strategies of spruce inner bark against the bark beetle (Ips typographus and associated blue stain fungus (Ceratocystis polonica.

  7. Assessing exergy of forest ecosystem using airborne and satellite data

    Science.gov (United States)

    Brovkina, Olga; Fabianek, Tomas; Lukes, Petr; Zemek, Frantisek

    2017-04-01

    Interactions of the energy flows of forest ecosystem with environment are formed by a suite of forest structure, functions and pathways of self-control. According to recent thermodynamic theory for open systems, concept of exergy of solar radiation has been applied to estimate energy consumptions on evapotranspiration and biomass production in forest ecosystem or to indicate forest decline and human land use impact on ecosystem stability. However, most of the methods for exergy estimation in forest ecosystem is not stable and its physical meaning remains on the surface. This study was aimed to contribute to understanding the exergy of forest ecosystem using combination of remote sensing (RS) and eddy covariance technologies, specifically: 1/to explore exergy of solar radiation depending on structure of solar spectrum (number of spectral bands of RS data), and 2/to explore the relationship between exergy and flux tower eddy covariance measurements. Two study forest sites were located in Western Beskids in the Czech Republic. The first site was dominated by young Norway spruce, the second site was dominated by mature European beech. Airborne hyperspectral data in VNIR, SWIR and TIR spectral regions were acquired 9 times for study sites during a vegetation periods in 2015-2016. Radiometric, geometric and atmospheric corrections of airborne data were performed. Satellite multispectral Landsat-8 cloud-free 21 scenes were downloaded and atmospherically corrected for the period from April to November 2015-2016. Evapotranspiration and latent heat fluxes were collected from operating flux towers located on study sites according to date and time of remote sensing data acquisition. Exergy was calculated for each satellite and airborne scene using various combinations of spectral bands as: Ex=E^out (K+ln E^out/E^in )+R, where Ein is the incoming solar energy, Eout is the reflected solar energy, R = Ein-Eout is absorbed energy, Eout/Ein is albedo and K is the Kullback increment

  8. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration

    OpenAIRE

    Guillaume Otis Prud'homme; Mohammed S. Lamhamedi; Lahcen Benomar; André Rainville; Josianne DeBlois; Jean Bousquet; Jean Bousquet; Jean Beaulieu; Jean Beaulieu

    2018-01-01

    With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea gl...

  9. Spruce needles used as radioecological biotracers; Fichtennadeln als radiooekologische Bioindikatoren

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, C.; Gruber, V.; Baumgartner, A. [BOKU - Univ. fuer Bodenkultur Wien (Austria). LLC-Labor Arsenal; Idinger, J. [Technische Univ. Wien (Austria). Atominst.; Fuerst, A. [BFW - Bundesforschungs- und Ausbildungszentrum fuer Wald, Naturgefahren und Landschaft, Wien (Austria). Inst. fuer Waldschutz, Pflanzenanalyse; Maringer, F.J. [BOKU - Univ. fuer Bodenkultur Wien (Austria). LLC-Labor Arsenal; BEV - Bundesamt fuer Eich- und Vermessungswesen, Wien (Austria)

    2009-07-01

    In a two years project spruce needle samples of the Austrian Bioindicator Grid were analysed by gamma-ray spectrometry to investigate the spatial and temporal distribution of radionuclides in spruce needles of the last 25 years with the main focus on the radioactive contamination before and after the Chernobyl fallout 1986. More than 600 spruce needle samples at selected locations of the Bioindicator Grid were analysed for different natural and anthropogenic radionuclides: {sup 137}Cs, {sup 40}K, {sup 210}Pb, {sup 226}Ra, {sup 228}Ra, {sup 238}U. Additionally, soil samples were taken at selected sites to study the soil-to-plant transfer. This radioecological evaluation is an important part of an existing environmental surveillance programme in Upper Austria in order to gain basic information on the impact of environmental changes on the radioecological behaviour of spruce trees. (orig.)

  10. Managing forest disturbances and community responses: lessons from the Kenai Peninsula, Alaska.

    Science.gov (United States)

    Courtney G. Flint; Richard. Haynes

    2006-01-01

    Managing forest disturbances can be complicated by diverse human community responses. Interview and quantitative analysis of mail surveys were used to assess risk perceptions and community actions in response to forest disturbance by spruce bark beetles. Despite high risk perception of immediate threats to personal safety and property, risk perceptions of broader...

  11. Modelling and economic evaluation of forest biome shifts under climate change in Southwest Germany

    Science.gov (United States)

    Marc Hanewinkel; Susan Hummel; Dominik. Cullmann

    2010-01-01

    We evaluated the economic effects of a predicted shift from Norway spruce (Picea abies) to European beech (Fagus sylvatica) for a forest area of 1.3 million ha in southwest Germany. The shift was modelled with a generalized linear model (GLM) by using presence/absence data from the National Forest Inventory in Baden-Wurttemberg...

  12. Carbon dioxide and water vapour exchange from understory species in boreal forest.

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Arp, W.J.; Chapin, F.S.

    2004-01-01

    Although recent eddy covariance measurements in boreal forests provide CO2 and energy exchange data for the whole ecosystem, very little is known about the role of the understory vegetation. We conducted chamber flux measurements in an Alaskan black spruce forest in order to compare CO2 and water

  13. Impact of Market-Based Disturbance on the Composition of West Virginia's Forest Resource

    Science.gov (United States)

    William G. Luppold; John E. Baumgras; John E. Baumgras

    2000-01-01

    The eastern hardwood resource has been shaped by a combination of human and natural disturbances. This impact on the forest resources of West Virginia has been especially dramatic. This resource has changed from a virgin forest dominated white oak, chestnut, spruce, white pine, and hemlock in the late 19th century, to one dominated by red oak in the 1950's, to...

  14. Pennsylvania boreal conifer forests and their bird communities: past, present, and potential

    Science.gov (United States)

    Douglas A. Gross

    2010-01-01

    Pennsylvania spruce (Picea spp.)- and eastern hemlock (Tsuga canadensis)-dominated forests, found primarily on glaciated parts of the Allegheny Plateau, are relicts of boreal forest that covered the region following glacial retreat. The timber era of the late 1800s and early 1900s (as late as 1942) destroyed most of the boreal...

  15. Estimation of forest structural parameters using 5 and 10 meter SPOT-5 satellite data

    Science.gov (United States)

    Peter T. Wolter; Phillip A. Townsend; Brian R. Sturtevant

    2009-01-01

    Large areas of forest in the US and Canada are affected by insects and disease each year. Over the past century, outbreaks of the Eastern spruce budworm have become more frequent and severe. The notion of designing a more pest resistant landscape through prescriptive management practices hinges on our ability to effectively model forest?insect dynamics at regional...

  16. Adaptive Evolution and Demographic History of Norway Spruce (Picea Abies)

    OpenAIRE

    Källman, Thomas

    2009-01-01

    One of the major challenges in evolutionary biology is to determine the genetic basis of adaptive variation. In Norway spruce (Picea abies) the timing of bud set shows a very strong latitudinal cline despite a very low genetic differentiation between populations. The timing of bud set in Norway spruce is under strong genetic control and triggered by changes in photoperiod, but no genes controlling this response have so far been described. In this thesis we used a combination of functional stu...

  17. Determination and analysis of uptake of gaseous hydrogen peroxide by red spruce seedlings, determined by CSTR-type chamber experiments

    International Nuclear Information System (INIS)

    Claiborn, C.S.; Aneja, V.P.; Carbonell, R.G.

    1991-01-01

    In order to better understand the pathways for damage, the fate of gaseous hydrogen peroxide in red spruce needles was examined. The uptake of gaseous hydrogen peroxide by red spruce trees was determined from controlled exposure chamber experiments in which the chamber behaved as a Continuous Stirred Tank Reactor (CSTR). The results from these experiments were analyzed using a detailed transport model developed from fundamental principles, in order to determine the fate of hydrogen peroxide in the needles and characterize the exposure. The chamber was specially designed to accommodate highly reactive gases. All inner surfaces were Teflon-coated to minimize wall losses. Fluxes of hydrogen peroxide, carbon dioxide, and water vapor were determined. Both daytime and nighttime conditions were examined. Although other investigators have reported that the flux of other, less water-soluble pollutants to red spruce decreases at night when the stomata closes, the hydrogen peroxide flux did not exhibit this behavior. The results of these studies suggest that, at the concentrations observed in the atmosphere, hydrogen peroxide does not reach the inner, mesophyll tissues, but is lost in water condensing in the cuticular wax residing in the stomatal antechamber, above the stomata. The implications of the condensation in the stomatal antechamber and subsequent reactions occurring in this water for forest damage are discussed

  18. Six-Year Nitrogen–Water Interaction Shifts the Frequency Distribution and Size Inequality of the First-Order Roots of Fraxinus mandschurica in a Mixed Mature Pinus koraiensis Forest

    Science.gov (United States)

    Wang, Cunguo; Geng, Zhenzhen; Chen, Zhao; Li, Jiandong; Guo, Wei; Zhao, Tian-Hong; Cao, Ying; Shen, Si; Jin, Daming; Li, Mai-He

    2017-01-01

    The variation in fine root traits in terms of size inequality at the individual root level can be identified as a strategy for adapting to the drastic changes in soil water and nutrient availabilities. The Gini and Lorenz asymmetry coefficients have been applied to describe the overall degree of size inequality, which, however, are neglected when conventional statistical means are calculated. Here, we used the Gini coefficient, Lorenz asymmetry coefficient and statistical mean in an investigation of Fraxinus mandschurica roots in a mixed mature Pinus koraiensis forest on Changbai Mountain, China. We analyzed 967 individual roots to determine the responses of length, diameter and area of the first-order roots and of branching intensity to 6 years of nitrogen addition (N), rainfall reduction (W) and their combination (NW). We found that first-order roots had a significantly greater average length and area but had smaller Gini coefficients in NW plots compared to in control plots (CK). Furthermore, the relationship between first-order root length and branching intensity was negative in CK, N, and W plots but positive in NW plots. The Lorenz asymmetry coefficient was >1 for the first-order root diameter in NW and W plots as well as for branching intensity in N plots. The bimodal frequency distribution of the first-order root length in NW plots differed clearly from the unimodal one in CK, N, and W plots. These results demonstrate that not only the mean but also the variation and the distribution mode of the first-order roots of F. mandschurica respond to soil nitrogen and water availability. The changes in size inequality of the first-order root traits suggest that Gini and Lorenz asymmetry coefficients can serve as informative parameters in ecological investigations of roots to improve our ability to predict how trees will respond to a changing climate at the individual root level. PMID:29018474

  19. Six-Year Nitrogen-Water Interaction Shifts the Frequency Distribution and Size Inequality of the First-Order Roots of Fraxinus mandschurica in a Mixed Mature Pinus koraiensis Forest.

    Science.gov (United States)

    Wang, Cunguo; Geng, Zhenzhen; Chen, Zhao; Li, Jiandong; Guo, Wei; Zhao, Tian-Hong; Cao, Ying; Shen, Si; Jin, Daming; Li, Mai-He

    2017-01-01

    The variation in fine root traits in terms of size inequality at the individual root level can be identified as a strategy for adapting to the drastic changes in soil water and nutrient availabilities. The Gini and Lorenz asymmetry coefficients have been applied to describe the overall degree of size inequality, which, however, are neglected when conventional statistical means are calculated. Here, we used the Gini coefficient, Lorenz asymmetry coefficient and statistical mean in an investigation of Fraxinus mandschurica roots in a mixed mature Pinus koraiensis forest on Changbai Mountain, China. We analyzed 967 individual roots to determine the responses of length, diameter and area of the first-order roots and of branching intensity to 6 years of nitrogen addition (N), rainfall reduction (W) and their combination (NW). We found that first-order roots had a significantly greater average length and area but had smaller Gini coefficients in NW plots compared to in control plots (CK). Furthermore, the relationship between first-order root length and branching intensity was negative in CK, N, and W plots but positive in NW plots. The Lorenz asymmetry coefficient was >1 for the first-order root diameter in NW and W plots as well as for branching intensity in N plots. The bimodal frequency distribution of the first-order root length in NW plots differed clearly from the unimodal one in CK, N, and W plots. These results demonstrate that not only the mean but also the variation and the distribution mode of the first-order roots of F. mandschurica respond to soil nitrogen and water availability. The changes in size inequality of the first-order root traits suggest that Gini and Lorenz asymmetry coefficients can serve as informative parameters in ecological investigations of roots to improve our ability to predict how trees will respond to a changing climate at the individual root level.

  20. Labeling Feral Spruce Budworm (Lepidoptera: Tortricidae) Populations With Rubidium.

    Science.gov (United States)

    MacKinnon, Wayne; Eveleigh, Eldon; Silk, Peter; Forbes, Glen

    2016-04-01

    Rubidium (Rb) is a trace element that occurs naturally in low concentrations and is easily absorbed by plants, making it a useful tool for labeling insect defoliators, such as spruce budworm (Choristoneura fumiferana Clemens). Balsam fir trees (Abies balsamea (L.) Miller) injected with either 8 or 16 g per tree of rubidium chloride (RbCl) showed quick uptake and distribution throughout the crown, with no negative effects on tree shoot growth or spruce budworm survival and development. Adult spruce budworm that fed as larvae on trees injected with RbCl were clearly labeled, with significantly higher Rb concentrations than the background levels found in adults that fed as larvae on control trees. Rb concentrations in feral spruce budworm adults for both the 8 g (9 µg/g) and 16 g (25 µg/g) per tree treatments were at least five times lower than those in laboratory-reared adults on 1,000 µg/g RbCl diet (125 µg/g); survival, development, pupal weight, sex ratio, and mating status of spruce budworm were not adversely affected by Rb treatment. Egg masses laid by feral females that fed as larvae on Rb-labeled trees were also labeled with Rb. Injecting trees with RbCl is a viable technique for labeling feral spruce budworm populations to help distinguish local populations from immigrants to better evaluate the success of early intervention strategies such as mating disruption. © Crown copyright 2016.

  1. Fire Severity Controlled Susceptibility to a 1940s Spruce Beetle Outbreak in Colorado, USA.

    Science.gov (United States)

    Kulakowski, Dominik; Veblen, Thomas T; Bebi, Peter

    2016-01-01

    The frequency, magnitude, and size of forest disturbances are increasing globally. Much recent research has focused on how the occurrence of one disturbance may affect susceptibility to subsequent disturbances. While much has been learned about such linked disturbances, the strength of the interactions is likely to be contingent on the severity of disturbances as well as climatic conditions, both of which can affect disturbance intensity and tree resistance to disturbances. Subalpine forests in western Colorado were affected by extensive and severe wildfires in the late 19th century and an extensive and severe outbreak of spruce beetle (Dendroctonus rufipennis) in the 1940s. Previous research found that most, but not all, of the stands that burned and established following the late 19th century fires were not susceptible to the 1940s outbreak as beetles preferentially attack larger trees and stands in advanced stages of development. However, previous research also left open the possibility that some stands that burned and established following the 19th century fires may have been attacked during the 1940s outbreak. Understanding how strongly stand structure, as shaped by disturbances of varying severity, affected susceptibility to past outbreaks is important to provide a baseline for assessing the degree to which recent climate change may be relaxing the preferences of beetles for larger trees and for stands in latter stages of structural development and thereby changing the nature of linked disturbances. Here, dendroecological methods were used to study disturbance history and tree age of stands in the White River National Forest in Western Colorado that were identified in historical documents or remotely-sensed images as having burned in the 19th century and having been attacked by spruce beetle in the 1940s. Dendroecological reconstructions indicate that in young post-fire stands only old remnant trees that survived the otherwise stand-replacing fires were

  2. Fire Severity Controlled Susceptibility to a 1940s Spruce Beetle Outbreak in Colorado, USA.

    Directory of Open Access Journals (Sweden)

    Dominik Kulakowski

    Full Text Available The frequency, magnitude, and size of forest disturbances are increasing globally. Much recent research has focused on how the occurrence of one disturbance may affect susceptibility to subsequent disturbances. While much has been learned about such linked disturbances, the strength of the interactions is likely to be contingent on the severity of disturbances as well as climatic conditions, both of which can affect disturbance intensity and tree resistance to disturbances. Subalpine forests in western Colorado were affected by extensive and severe wildfires in the late 19th century and an extensive and severe outbreak of spruce beetle (Dendroctonus rufipennis in the 1940s. Previous research found that most, but not all, of the stands that burned and established following the late 19th century fires were not susceptible to the 1940s outbreak as beetles preferentially attack larger trees and stands in advanced stages of development. However, previous research also left open the possibility that some stands that burned and established following the 19th century fires may have been attacked during the 1940s outbreak. Understanding how strongly stand structure, as shaped by disturbances of varying severity, affected susceptibility to past outbreaks is important to provide a baseline for assessing the degree to which recent climate change may be relaxing the preferences of beetles for larger trees and for stands in latter stages of structural development and thereby changing the nature of linked disturbances. Here, dendroecological methods were used to study disturbance history and tree age of stands in the White River National Forest in Western Colorado that were identified in historical documents or remotely-sensed images as having burned in the 19th century and having been attacked by spruce beetle in the 1940s. Dendroecological reconstructions indicate that in young post-fire stands only old remnant trees that survived the otherwise stand

  3. Cytokinin concentrations in the foliage of spruce trees (Picea abies (L. ) Karst. ) affected to different degrees by 'recently discovered forms of forest disease' as determined in immunoenzymatic assays (ELISA). Der Cytokiningehalt in Nadeln unterschiedlich stark von 'neuartigen Waldschaeden' betroffenen Fichten (Picea abies (L. ) Karst. ), bestimmt mittels einer immunoenzymatischen Methode - ELISA

    Energy Technology Data Exchange (ETDEWEB)

    Schwartzenberg, K von

    1989-09-25

    This report attempts to find an answer to the question as to whether the cytokinin concentrations in the leaves of spruce trees showing discolouration or loss of foliage would be any different from those determined for trees, in which no such changes have occurred. Described is a specific analytical method developed for quantitative determinations of the cytokinins trans-zeatin (t-Z), trans-zeatin riboside (t-ZR), isopentenyladenine (ZiP) and isopentenyladenosine (ZiPA). In all, it was found that the levels determined for cytokinin ribosides in needles of the older age groups tested were quite consistent with the degree of discolouration and general damage observed in those trees. Fumigation experiments were additionally performed to find out which effect 8-11 weeks of exposure to an air pollutant, ozone, would have on young spruces. Initial measurements carried out in exposed and non-exposed plants do not yet permit any predictions to be made about the probable influence of ozone on the cytokinin concentrations of foliage. (KST).

  4. Application of Unmanned Aircraft Systems (UAS) for phenotypic mapping of white spruce genotypes along environmental gradients

    Science.gov (United States)

    D'Odorico, P.; Wong, C. Y.; Besik, A.; Earon, E.; Isabel, N.; Ensminger, I.

    2017-12-01

    Rapid climate change is expected to cause a mismatch between locally adapted tree populations and the optimal climatic conditions to which they have adapted. Plant breeding and reforestation programs will increasingly need to rely on high-throughput precision phenotyping tools for the selection of genotypes with increased drought and stress tolerance. In this work, we present the possibilities offered by Unmanned Aircraft Systems (UAS) carrying optical sensors to monitor and assess differences in performance among white spruce genotypes. While high-throughput precision phenotyping using UAS has gained traction in agronomic crop research during the last few years, to our knowledge it is still at its infancy in forestry applications. UAS surveys were performed at different times during the growing season over large white spruce common garden experiments established by the Canadian Forest Service at four different sites, each characterized by 2000 clonally replicated genotypes. Sites are distributed over a latitudinal gradient, in Ontario and Quebec, Canada. The UAS payload consisted of a custom-bands multispectral sensor acquiring radiation at wavelength at which the reflectance spectrum of vegetation is known to capture physiological change under disturbance and stress. Ground based tree-top spectral reflectances and leaf level functional traits were also acquired for validation purposes parallel to UAS surveys. We will discuss the potential and the challenges of using optical sensors on UAS to infer genotypic variation in tree response to stress events and show how spectral data can function as the link between large-scale phenotype and genotype data.

  5. Ecosystem warming does not affect photosynthesis or aboveground autotrophic respiration for boreal black spruce

    Energy Technology Data Exchange (ETDEWEB)

    Bronson, D.R. [Wyoming Univ., Laramie, WY (United States). Dept. of Renewable Resources; Gower, S.T. [Wisconsin Univ., Madison, WI (United States). Dept. of Forest Ecology and Management

    2010-04-15

    Substantial increases in climatic temperatures may cause boreal forests to become a carbon source. An improved understanding of the effect of climatic warming on photosynthesis and autotrophic respiration is needed in order to determine the impact of temperature increases on net carbon balances. This study measured the light-saturated photosynthesis foliage respiration and stem respiration of black spruce in heated and control plots during a 3-year period at a site located in Thompson, Manitoba. Greenhouses and soil-heating cables were used to maintain air and soil temperatures at 5 degrees C above ambient air and soil temperatures. Studies were conducted to determine the influence of soil and air warming; soil-only warming; and greenhouses maintained at ambient temperatures. The study showed that treatment differences for photosynthesis, foliage respiration, and stem respiration were not significant over the 3-year period. Results suggested that black spruce may not have significant changes in photosynthesis or respiration rates in warmer climates. 38 refs., 3 tabs., 4 figs.

  6. Availability of ectomycorrhizal fungi to black spruce above the present treeline in Eastern Labrador.

    Directory of Open Access Journals (Sweden)

    Laura Reithmeier

    Full Text Available Ectomycorrhizal fungi (ECMF are an important biotic factor in the survival of conifer seedlings under stressful conditions and therefore have the potential to facilitate conifer establishment into alpine and tundra habitats. In order to assess patterns of ectomycorrhizal availability and community structure above treeline, we conducted soil bioassays in which Picea mariana (black spruce seedlings were grown in field-collected soils under controlled conditions. Soils were collected from distinct alpine habitats, each dominated by a different ectomycorrhizal host shrub: Betula glandulosa, Arctostaphylos alpina or Salix herbacaea. Within each habitat, half of the soils collected contained roots of ectomycorrhizal shrubs (host (+ and the other half were free of host plants (host(-. Forest and glacial moraine soils were also included for comparison. Fungi forming ectomycorrhizae during the bioassays were identified by DNA sequencing. Our results indicate that ECMF capable of colonizing black spruce are widespread above the current tree line in Eastern Labrador and that the level of available inoculum has a significant influence on the growth of seedlings under controlled conditions. Many of the host(- soils possessed appreciable levels of ectomycorrhizal inoculum, likely in the form of spore banks. Inoculum levels in these soils may be influenced by spore production from neighboring soils where ectomycorrhizal shrubs are present. Under predicted temperature increases, ectomycorrhizal inoculum in soils with host shrubs as well as in nearby soils without host shrubs have the potential to facilitate conifer establishment above the present tree line.

  7. Availability of ectomycorrhizal fungi to black spruce above the present treeline in Eastern Labrador.

    Science.gov (United States)

    Reithmeier, Laura; Kernaghan, Gavin

    2013-01-01

    Ectomycorrhizal fungi (ECMF) are an important biotic factor in the survival of conifer seedlings under stressful conditions and therefore have the potential to facilitate conifer establishment into alpine and tundra habitats. In order to assess patterns of ectomycorrhizal availability and community structure above treeline, we conducted soil bioassays in which Picea mariana (black spruce) seedlings were grown in field-collected soils under controlled conditions. Soils were collected from distinct alpine habitats, each dominated by a different ectomycorrhizal host shrub: Betula glandulosa, Arctostaphylos alpina or Salix herbacaea. Within each habitat, half of the soils collected contained roots of ectomycorrhizal shrubs (host (+)) and the other half were free of host plants (host(-)). Forest and glacial moraine soils were also included for comparison. Fungi forming ectomycorrhizae during the bioassays were identified by DNA sequencing. Our results indicate that ECMF capable of colonizing black spruce are widespread above the current tree line in Eastern Labrador and that the level of available inoculum has a significant influence on the growth of seedlings under controlled conditions. Many of the host(-) soils possessed appreciable levels of ectomycorrhizal inoculum, likely in the form of spore banks. Inoculum levels in these soils may be influenced by spore production from neighboring soils where ectomycorrhizal shrubs are present. Under predicted temperature increases, ectomycorrhizal inoculum in soils with host shrubs as well as in nearby soils without host shrubs have the potential to facilitate conifer establishment above the present tree line.

  8. Pathogenicity of Neonectria fuckeliana on Norway Spruce Clones in Sweden and Potential Management Strategies

    Directory of Open Access Journals (Sweden)

    Martin Pettersson

    2018-02-01

    Full Text Available The fungus Neonectria fuckeliana has become an increasing problem on Norway spruce (Picea abies in the Nordic countries during recent years. Canker wounds caused by the pathogen reduce timber quality and top-dieback is a problem for the Christmas tree industry. In this study, four inoculation trials were conducted to examine the ability of N. fuckeliana to cause disease on young Norway spruce plants and determine how different wound types would affect the occurrence and severity of the disease. Symptom development after 8–11 months was mainly mild and lesion lengths under bark were generally minor. However, N. fuckeliana could still be reisolated and/or molecularly detected. Slow disease development is in line with older studies describing N. fuckeliana as a weak pathogen. However, the results do not explain the serious increased damage by N. fuckeliana registered in Nordic forests and Christmas tree plantations. Potential management implications, such as shearing Christmas trees during periods of low inoculum pressure, cleaning secateurs between trees, and removal and burning of diseased branches and trees to avoid inoculum transfer and to keep disease pressure low, are based on experiments presented here and experiences with related pathogens.

  9. Energy wood harvesting from nurse crop of spruce seeding stand; Kuusen taimikon verhopuuston korjuu energiapuuksi

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, M.; Tanttu, V.

    2008-07-01

    The study focused on establishing the productivity and costs of mechanical energy wood cutting and the profitability of forest management alternatives in the harvesting of hold-overs from spruce seeding stands. The productivity in whole-tree harvesting performed using a multi-tree whole tree processing method reached 3.5 m3/E{sub 0}h with a felling cost of 26 euros/m3. The calculated cost of chainsaw harvesting using a felling-piling technique was 16 euros/m3. The average size of trees harvested from the research stand was 15 dm3. At a rate of 17.8 euros per megawatt that was paid for forest chips delivered to the plant, the net profit using mechanical harvesting method was 272 euros per hectare. The net profit using chainsaw harvesting was 464 euros per hectare. 'Net profit' is defined here as the total amount earned, taking into account forest management costs, the production cost of forest chips, the Kemera subsidies and the price paid for the chips at the place of usage. The net profit of felling the removed trees to the ground (not processing it into fuel) was minus 124 euros. A theoretical stumpage price rate was calculated for the energy harvesting alternatives by dividing the net result by the volume of trees harvested. Theoretical stumpage price was positive when the paid price per megawatt of chips delivered to the place of usage was 13 euros per megawatt-hour for mechanically harvested chips or 10 euros per megawatt-hour for chainsaw-harvested chips. In mechanical harvesting, 17 percent of the trees harvested were damaged in the harvesting process. While it is often essential for the forest owner to ensure that any forest management measures contribute to quick profitability, the forest management benefits that will become realisable assets in the future must nevertheless also be taken into account. (orig.)

  10. Pollution control enhanced spruce growth in the “Black Triangle” near the Czech–Polish border

    Czech Academy of Sciences Publication Activity Database

    Kolář, Tomáš; Čermák, P.; Oulehle, Filip; Trnka, Miroslav; Štěpánek, Petr; Cudlín, Pavel; Hruška, Jakub; Büntgen, Ulf; Rybníček, Michal

    2015-01-01

    Roč. 538, 15 Dec (2015), s. 703-711 ISSN 0048-9697 R&D Projects: GA MŠk(CZ) EE2.3.20.0265; GA MŠk(CZ) LO1415; GA MŠk(CZ) EE2.3.20.0248; GA ČR GA13-04291S; GA ČR(CZ) GA15-08124S Institutional support: RVO:67179843 Keywords : air pollution * Central Europe * dendroecology * forest growth * Norway spruce Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.976, year: 2015

  11. Sobrevivência de plântulas transplantadas de uma floresta tropical madura para viveiro de mudas na bacia do rio Xingu. Survival of seedlings transplanted from a mature tropical forest to nursery in Xingu river basin.

    Directory of Open Access Journals (Sweden)

    Roberta Thays dos Santos CURY

    2013-06-01

    Full Text Available A utilização da diversidade de plântulas de espécies arbóreas, oriundas de áreas cuja vegetação teve a supressão autorizada, no enriquecimento de viveiros, tem sido recomendada como uma técnica alternativa na produção de mudas. Neste trabalho, avaliamos a sobrevivência de plântulas transplantadas da regeneração natural de uma floresta madura para um viveiro de mudas em uma área de transição Amazônia-Cerrado, Mato Grosso, Brasil. Foram alocados três transectos de 10 x 1 m, com 10, 50 e 500 m de distância da borda de onde foram coletados todos os indivíduos lenhosos entre 5-20 cm de altura, no período da manhã (7h às 9h, e sequencialmente plantados em sacos plásticos. Os indivíduos foram identificados, quantificados e classificados quanto ao estágio sucessional. A sobrevivência das plântulas foi avaliada durante quatro meses. No total foram coletados 1.179 indivíduos arbóreos pertencentes a 48 espécies, 31 gêneros e 23 famílias, dos quais 71% sobreviveram. No conjunto dos dados, houve um aumento gradativo na abundância e riqueza de espécies arbóreas da borda para o interior da floresta, sendo maior a 500 m. A abundância e o número de espécies não pioneiras coletadas foram maiores que as pioneiras. Os resultados apontam elevadas taxas de sobrevivência e que a técnica de transplante pode facilitar o enriquecimento de viveiros com espécies regionais de difícil obtenção e de diferentes grupos funcionais. The use of the diversity of tree species, present in areas where vegetation removal had been authorized, as means of nursery enrichment, has been recommended as an alternative technique for seedling production. The aim of this study was to evaluate the survival rate of transplanted seedlings, from natural regeneration in mature forests, to the nursery. Seedlings were obtained from three 10 x 1 m transects allocated in Amazon transitional forest in Mato Grosso state, Brazil. All woody individuals with

  12. Effect of industrial pollution on behaviour of radionuclides in forest ecosystems; Forests ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Outola, I. (STUK-Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    To investigate how and to what extent industrial pollution affects the behaviour of radionuclides in forest ecosystems, studies were conducted in the vicinity of two Cu-Ni smelters: one in a pine forest at Harjavalta, Finland, and the other in a spruce forest at Monchegorsk, Russia. Industrial pollution had significant effects on the distribution of radionuclides in soil horizons. With the increase in pollution towards the smelter, radionuclides were accumulated more in the litter layer because the conversion of litter into organic material was diminished due to inhibited microbial activity. As a result, the organic layer contained less radionuclides towards the smelter. The effect of industrial pollution on soil-to-plant transfer was complex. The effect varied with radionuclide, plant species and also on forest type. For 137Cs, soil-to-plant transfer decreased significantly as industrial pollution increased in pine forest, whereas the decrease was less pronounced in spruce forest. Root uptake of 239,240Pu by plants is extremely small, and plant contamination by resuspended soil is an important factor in considering the soil-to-plant transfer of this radionuclide. In spruce forest, more plutonium was transferred into plants when pollution load increased due to resuspension of litter particles, which contained higher concentrations of plutonium in the vicinity of the smelter. Soil-to-plant transfer of plutonium was much less affected in pine forests contaminated with industrial pollution. This research clearly indicates the sensitivity of the northern forest ecosystem to inorganic pollutants. Prediction of the soil-to-plant transfer of radionuclides in industrially polluted forest ecosystems requires detailed information on the total deposition, vertical distribution of radionuclides in soil, soil microbiological factors, other soil parameters as well as the rooting depths of the plants. (LN)

  13. Acid atmospheric deposition in a forested mountain catchment

    Czech Academy of Sciences Publication Activity Database

    Křeček, J.; Palán, L.; Stuchlík, Evžen

    2017-01-01

    Roč. 10, č. 4 (2017), s. 680-686 ISSN 1971-7458 Institutional support: RVO:60077344 Keywords : mountain water shed * spruce forests * acid atmospheric deposition * water resources recharge Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.623, year: 2016

  14. Woody debris dynamics in Interior West forests and woodlands

    Science.gov (United States)

    John D. Shaw; James Long; Raffaella Marzano; Matteo Garbarino

    2012-01-01

    Managers are interested in the dynamics of down woody material because of its role as a fuel component, a feature of wildlife habitat, a carbon pool, and other characteristics. We analyzed nearly 9,000 plots from the Interior West, spanning the range from sparse juniper and mesquite woodland to dense spruce-fir forests, in order to characterize down woody material as...

  15. The care and handling of the forest gene pool

    Science.gov (United States)

    Roy R. Silen; Ivan Doig

    1976-01-01

    What must be the world's most magnificent pool of forest genes has timbered our Pacific slopes.Why else do the tallest firs, pines, spruces, hemlocks, redwoods, and larches all rise along the Pacific Coast of North America? Does their hugeness simply thrust up from our deep soils and mild, rainy climate? From a vantage point of three...

  16. The effect of the environment on the structure, quantity and composition of spruce needle wax

    International Nuclear Information System (INIS)

    Guenthardt-Goerg, M.S.

    1994-01-01

    The tubular structure (10-nonacosanol), as formed in spring on the wax surface of new spruce needles (Picea abies (L.)Karst.), or as regenerated on previous-year needles, becomes gradually fused and flattened in relation to needle exposure, particularly wind and rain. Structural flattening does not necessarily imply changes in wax quantity, composition or lead to changes in needle transpiration or photosynthesis, and was approximately reproduced by bathing excised twigs in water (with pH having little effect). In 4-year-old plants of one clone planted out at a Swiss plateau and alpine sites, changes in wax structure were similar to those found in mature trees. No such changes were found in plants with O 3 , SO 2 , ambient air, charcoal-filtered air, or in plants grown outside the chambers but shielded from rain. Area-related needle wax quantity in mature trees differed between the two sites, but did not differ in young plants under different treatments (fumigation or planted out at the sites). Minor differences in wax composition, however, were found to be related to the ozone dose of the fumigation or the ambient ozone dose at the sites. In each needle wax sample, 68 compounds grouped into 12 constituent classes were quantified. The quantity of the individual substituent classes varied among wax samples from genetically different mature trees at the two sites in a tree-specific way. Variation of these quantities was not larger than among young cloned plants after different treatments. (orig.)

  17. Maturity and maturity models in lean construction

    Directory of Open Access Journals (Sweden)

    Claus Nesensohn

    2014-03-01

    Full Text Available In recent years there has been an increasing interest in maturity models in management-related disciplines; which reflects a growing recognition that becoming more mature and having a model to guide the route to maturity can help organisations in managing major transformational change. Lean Construction (LC is an increasingly important improvement approach that organisations seek to embed. This study explores how to apply the maturity models to LC. Hence the attitudes, opinions and experiences of key industry informants with high levels of knowledge of LC were investigated. To achieve this, a review of maturity models was conducted, and data for the analysis was collected through a sequential process involving three methods. First a group interview with seven key informants. Second a follow up discussion with the same individuals to investigate some of the issues raised in more depth. Third an online discussion held via LinkedIn in which members shared their views on some of the results. Overall, we found that there is a lack of common understanding as to what maturity means in LC, though there is general agreement that the concept of maturity is a suitable one to reflect the path of evolution for LC within organisations.

  18. Slab replacement maturity guidelines.

    Science.gov (United States)

    2014-04-01

    This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

  19. The effects of pelleted sewage sludge on Norway spruce establishment and nitrogen dynamics

    International Nuclear Information System (INIS)

    Johannesson, Anders

    1999-01-01

    In Sweden there is a big resource in unutilised sewage sludge. Studies have shown that application of municipal sewage sludge can improve forest productivity and planting environment. This study is examining the effects of two types of pelleted sewage sludge (pure sludge and a mixture of sludge and domestic wastes compost) on nitrogen turnover. Large differences were found in the fertilisation effect of the different treatments. The pure sewage sludge pellets treatment showed significant increases for NH 4 -accumulation, nitrification and NO 3 -leaching in the top 10 cm of the soil. Uptake of nitrogen was increased in spruce plants and vegetation. The mixed sludge/domestic waste pellets treatment showed indications of a minor initial release of nitrogen. This is seen as a small but significant initial increase in soil nitrification. These results suggest that the pure sewage sludge pellet is an adequate nitrogen fertiliser. The mixed sludge though is inadequate at least in the short run

  20. Feedbacks of windthrow for Norway spruce and Scots pine stands under changing climate

    DEFF Research Database (Denmark)

    Panferov, O.; Döring, C.; Rauch, E.

    2009-01-01

    is currently being developed at Göttingen University aims at providing a tool for the quantitative assessment of biotic and abiotic risks for forest ecosystems under the conditions of changing climate. In order to assess the future risks of wind damage the system employs a coupled modelling approach combining...... the turbulence model SCAlar DIStribution (SCADIS) with the soil–vegetation–atmosphere-transfer (SVAT) model BROOK 90. The present study investigates projections of wind damage in Solling, Germany under climate scenarios A1B and B1, taking into account the windthrow feedbacks—changes of microclimate as a result...... the probability of damage would be higher than under B1 and that under the same climate and soil conditions the risk for spruce stands would be higher than for pine stands of equal age. The degree of damage and feedback contribution as well as a sign of feedback in each particular case will strongly depend...