Sample records for subalpine spruce forest

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

    Directory of Open Access Journals (Sweden)

    Jesse L. Morris1


    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

  2. A Bayesian Analysis Shows That a Spruce Beetle Outbreak Reduces Snow Interception and Sublimation in a Subalpine Spruce-Fir Forest (United States)

    Frank, J. M.; Massman, W. J.; Ewers, B. E.; Williams, D. G.


    Sublimation is a key component in the water cycle of cold, snow dominated ecosystems. In many high elevation spruce-fir forests of western North America, recent spruce beetle outbreaks have caused widespread tree mortality, opened the canopy, and potentially altered the processes that control sublimation. This study evaluates three hypotheses: in these ecosystems the dominant source for sublimation originates from canopy intercepted snow, the loss of canopy following a beetle disturbance leads to significantly less sublimation, and major sublimation events are driven by the flow of sensible heat into the canopy. Bayesian analysis is used to evaluate a two source energy and canopy mass model that explains seventeen years (2000-2016) of winter eddy-covariance flux data at the GLEES AmeriFlux sites where a spruce beetle outbreak caused 75-85% basal area mortality. The model estimated that the resistance to snow sublimation from the canopy was an order of magnitude less than from the snowpack and that the maximum snow loading in the canopy was reduced to 25-56% of its pre-outbreak capacity. Comparing model results obtained using the observed decrease in leaf area index versus a "no beetle" condition, there has been a significant decrease in ecosystem sublimation since 2011. In the past few years, a 5-11% increase in snowpack sublimation has been offset by 28-32% less sublimation from canopy intercepted snow, with the net being 17-25% less total sublimation. This is equivalent to 3-6% of the total precipitation. Informing the model with information other than the above-canopy fluxes indicates that a near snowpack eddy covariance system decreases the canopy contribution to sublimation, including observed sensible heat fluxes requires a correction to resolve the surface energy imbalance, and stable isotopes of water vapor extend sublimation events. Because tree growth and ecological succession are slow in spruce-fir forests, these results could persist for decades.

  3. Soil attributes and microclimate are important drivers of initial deadwood decay in sub-alpine Norway spruce forests. (United States)

    Fravolini, Giulia; Egli, Markus; Derungs, Curdin; Cherubini, Paolo; Ascher-Jenull, Judith; Gómez-Brandón, María; Bardelli, Tommaso; Tognetti, Roberto; Lombardi, Fabio; Marchetti, Marco


    Deadwood is known to significantly contribute to global terrestrial carbon stocks and carbon cycling, but its decay dynamics are still not thoroughly understood. Although the chemistry of deadwood has been studied as a function of decay stage in temperate to subalpine environments, it has generally not been related to time. We therefore studied the decay (mass of deadwood, cellulose and lignin) of equal-sized blocks of Picea abies wood in soil-mesocosms over two years in the Italian Alps. The 8 sites selected were along an altitudinal sequence, reflecting different climate zones. In addition, the effect of exposure (north- and south-facing slopes) was taken into account. The decay dynamics of the mass of deadwood, cellulose and lignin were related to soil parameters (pH, soil texture, moisture, temperature) and climatic data. The decay rate constants of Picea abies deadwood were low (on average between 0.039 and 0.040y(-1)) and of lignin close to zero (or not detectable), while cellulose reacted much faster with average decay rate constants between 0.110 and 0.117y(-1). Our field experiments showed that local scale factors, such as soil parameters and topographic properties, influenced the decay process: higher soil moisture and clay content along with a lower pH seemed to accelerate wood decay. Interestingly, air temperature negatively correlated with decay rates or positively with the amount of wood components on south-facing sites. It exerted its influence rather on moisture availability, i.e. the lower the temperature the higher the moisture availability. Topographic features were also relevant with generally slower decay processes on south-facing sites than on north-facing sites owing to the drier conditions, the higher pH and the lower weathering state of the soils (less clay minerals). This study highlights the importance of a multifactorial consideration of edaphic parameters to unravel the complex dynamics of initial wood decay. Copyright © 2016 Elsevier

  4. Disturbance and Stand Development of a Colorado Subalpine Forest


    Veblen, Thomas T.; Hadley, Keith S; Reid, Marion S


    Stand development patterns were examined in an Engelmann spruce (Picea engelmannii), subalpine fir (Abies lasiocarpa) and lodgepole pine (Pinus contorta var. latifolia) forest in Rocky Mountain National Park in northern Colorado. Two old-growth stands (with fine-scale windthrows dominating dynamics) and a 260-yr-old post-fire stand were sampled for tree ages, sizes, growth, and replacement patterns in windthrow gaps. Visual assessment of frequency of growth releases in increment cores, and de...

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


    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

  6. Drought-driven disturbance history characterizes a southern Rocky Mountain subalpine forest (United States)

    R. Justin DeRose; James N. Long


    The view that subalpine forest vegetation dynamics in western North America are "driven" by a particular disturbance type (i.e., fire) has shaped our understanding of their disturbance regimes. In the wake of a recent (1990s) landscape- extent spruce beetle (Dendroctonus rufipennis Kirby) outbreak in the southern Rocky Mountains, we re-examined the temporal...

  7. Warming and provenance limit tree recruitment across and beyond the elevation range of subalpine forest. (United States)

    Kueppers, Lara M; Conlisk, Erin; Castanha, Cristina; Moyes, Andrew B; Germino, Matthew J; de Valpine, Perry; Torn, Margaret S; Mitton, Jeffry B


    Climate niche models project that subalpine forest ranges will extend upslope with climate warming. These projections assume that the climate suitable for adult trees will be adequate for forest regeneration, ignoring climate requirements for seedling recruitment, a potential demographic bottleneck. Moreover, local genetic adaptation is expected to facilitate range expansion, with tree populations at the upper forest edge providing the seed best adapted to the alpine. Here, we test these expectations using a novel combination of common gardens, seeded with two widely distributed subalpine conifers, and climate manipulations replicated at three elevations. Infrared heaters raised temperatures in heated plots, but raised temperatures more in the forest than at or above treeline because strong winds at high elevation reduced heating efficiency. Watering increased season-average soil moisture similarly across sites. Contrary to expectations, warming reduced Engelmann spruce recruitment at and above treeline, as well as in the forest. Warming reduced limber pine first-year recruitment in the forest, but had no net effect on fourth-year recruitment at any site. Watering during the snow-free season alleviated some negative effects of warming, indicating that warming exacerbated water limitations. Contrary to expectations of local adaptation, low-elevation seeds of both species initially recruited more strongly than high-elevation seeds across the elevation gradient, although the low-provenance advantage diminished by the fourth year for Engelmann spruce, likely due to small sample sizes. High- and low-elevation provenances responded similarly to warming across sites for Engelmann spruce, but differently for limber pine. In the context of increasing tree mortality, lower recruitment at all elevations with warming, combined with lower quality, high-provenance seed being most available for colonizing the alpine, portends range contraction for Engelmann spruce. The lower

  8. Warming and provenance limit tree recruitment across and beyond the elevation range of subalpine forest (United States)

    Kueppers, Lara M.; Conlisk, Erin; Castanha, Cristina; Moyes, Andrew B.; Germino, Matthew; de Valpine, Perry; Torn, Margaret S.; Mitton, Jeffry B.


    Climate niche models project that subalpine forest ranges will extend upslope with climate warming. These projections assume that the climate suitable for adult trees will be adequate for forest regeneration, ignoring climate requirements for seedling recruitment, a potential demographic bottleneck. Moreover, local genetic adaptation is expected to facilitate range expansion, with tree populations at the upper forest edge providing the seed best adapted to the alpine. Here, we test these expectations using a novel combination of common gardens, seeded with two widely distributed subalpine conifers, and climate manipulations replicated at three elevations. Infrared heaters raised temperatures in heated plots, but raised temperatures more in the forest than at or above treeline because strong winds at high elevation reduced heating efficiency. Watering increased season-average soil moisture similarly across sites. Contrary to expectations, warming reduced Engelmann spruce recruitment at and above treeline, as well as in the forest. Warming reduced limber pine first-year recruitment in the forest, but had no net effect on fourth-year recruitment at any site. Watering during the snow-free season alleviated some negative effects of warming, indicating that warming exacerbated water limitations. Contrary to expectations of local adaptation, low-elevation seeds of both species initially recruited more strongly than high-elevation seeds across the elevation gradient, although the low-provenance advantage diminished by the fourth year for Engelmann spruce, likely due to small sample sizes. High- and low-elevation provenances responded similarly to warming across sites for Engelmann spruce, but differently for limber pine. In the context of increasing tree mortality, lower recruitment at all elevations with warming, combined with lower quality, high-provenance seed being most available for colonizing the alpine, portends range contraction for Engelmann spruce. The lower

  9. Similarity of nutrient uptake and root dimensions of Engelmann spruce and subalpine fir at two contrasting sites in Colorado

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    Yanai, R; McFarlane, K; Lucash, M; Kulpa, S; Wood, D


    Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96 hours, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P > 0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P = 0.01, 0.15, 0.03, 0.18 for NH{sub 4}{sup +}, NO{sub 3}{sup -}, Ca{sup 2+}, and K{sup +}, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were 0.12 {micro}mol NH{sub 4}{sup +} g{sub fwt}{sup -1} h{sup -1}, 0.02 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1}, 0.21 {micro}mol Ca{sup 2+} g{sub fwt}{sup -1} h{sup -1}, and 0.01 {micro}mol Mg{sup 2+} g{sub fwt}{sup -1} h{sup -1} at Loch Vale, and 0.21 {micro}mol NH{sub 4}{sup +} f{sub fwt}{sup -1}h{sup -1}, 0.04 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1} h{sup -1}, 0.51 {micro}mol Ca{sup 2+}g{sub fwt}{sup -1}h{sup -1}, and 0.07 {micro}mol Mg{sup 2+} f{sub fwt}{sup -1}h{sup -1} at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelman spruce and subalpine fir

  10. Holocene vegetation and fire regimes in subalpine and mixed conifer forests, southern Rocky Mountains, USA (United States)

    Anderson, R. Scott; Allen, Craig D.; Toney, J.L.; Jass, R.B.; Bair, A.N.


    Our understanding of the present forest structure of western North America hinges on our ability to determine antecedent forest conditions. Sedimentary records from lakes and bogs in the southern Rocky Mountains of Colorado and New Mexico provide information on the relationships between climate and vegetation change, and fire history since deglaciation. We present a new pollen record from Hunters Lake (Colorado) as an example of a high-elevation vegetation history from the southern Rockies. We then present a series of six sedimentary records from ???2600 to 3500-m elevation, including sites presently at the alpine?subalpine boundary, within the Picea engelmannii?Abies lasiocarpa forest and within the mixed conifer forest, to determine the history of fire in high-elevation forests there. High Artemisia and low but increasing percentages of Picea and Pinus suggest vegetation prior to 13 500 calendar years before present (cal yr BP) was tundra or steppe, with open spruce woodland to ???11 900 cal yr BP. Subalpine forest (Picea engelmannii, Abies lasiocarpa) existed around the lake for the remainder of the Holocene. At lower elevations, Pinus ponderosa and/or contorta expanded 11 900 to 10 200 cal yr BP; mixed conifer forest expanded ???8600 to 4700 cal yr BP; and Pinus edulis expanded after ???4700 cal yr BP. Sediments from lake sites near the alpine?subalpine transition contained five times less charcoal than those entirely within subalpine forests, and 40 times less than bog sites within mixed conifer forest. Higher fire episode frequencies occurred between ???12 000 and 9000 cal yr BP (associated with the initiation or expansion of south-west monsoon and abundant lightning, and significant biomass during vegetation turnover) and at ???2000?1000 cal yr BP (related to periodic droughts during the long-term trend towards wetter conditions and greater biomass). Fire episode frequencies for subalpine?alpine transition and subalpine sites were on average 5 to 10 fire

  11. Evidence of compounded disturbance effects on vegetation recovery following high-severity wildfire and spruce beetle outbreak

    National Research Council Canada - National Science Library

    Amanda R Carlson; Jason S Sibold; Timothy J Assal; Jose F Negrón


    Spruce beetle (Dendroctonus rufipennis) outbreaks are rapidly spreading throughout subalpine forests of the Rocky Mountains, raising concerns that altered fuel structures may increase the ecological severity of wildfire...

  12. [Dynamic changes of topsoil organic carbon in subalpine spruce plantation at different succession stages in western Sichuan Province]. (United States)

    Jiang, Fa-Yan; Sun, Hui; Lin, Bo; Liu, Qing


    Soil samples at 0-30 cm depth were collected from the primary spruce (Picea asperata) forest and its plantations at different succession stages (22-, 47-, and 65-year-old) in subalpine zone of western Sichuan Province to study the dynamic changes of soil organic carbon stock and labile organic carbon content. The soil total organic carbon (TOC) stocks in 0-10, 10-20, and 20-30 cm soil layers decreased from 95.87, 79.08, and 71.55 t x hm(-2) in 22-year-old plantation to 56.12, 34.75, and 31.06 t x hm(-2) in 65-year-old plantation, respectively, and the TOC stocks in these soil layers in 47 and 65-year-old plantations were less than those (88.08, 71.16 and 64.81 t x hm(-2), respectively) in primary forest. The easily oxidizable organic carbon (EOC) contents in 0-10, 10-20, and 20-30 cm soil layers decreased from 35.89, 26.91, and 26.00 g x kg(-1) in primary forest to 20.25, 14.50, and 12.36 g x kg L(-1) in 65-year-old plantation, the microbial biomass carbon (MBC) contents decreased from 524.44, 273.26, and 257.97 mg x kg(-1) in primary forest to 312.41, 186.95, and 152.18 mg x kg(-1) in 65-year-old plantation, and the particulate organic carbon (POC) contents decreased from 40.23, 27.10, and 19.55 g x kg(-1) in primary forest to 12.33, 7.31, and 5.32 g x kg(-1) in 65-year-old plantation, respectively. The results suggested that within the long succession period of primary P. asperata forest to its plantations in the subalpine zone of western Sichuan Province, soil TOC and labile organic carbon were in the state of net consumption.

  13. Spectral evidence of early-stage spruce beetle infestation in Engelmann spruce (United States)

    Adrianna C. Foster; Jonathan A. Walter; Herman H. Shugart; Jason Sibold; Jose Negron


    Spruce beetle (Dendroctonus rufipennis (Kirby)) outbreaks cause widespread mortality of Engelmann spruce (Picea engelmannii (Parry ex Engelm)) within the subalpine forests of the western United States. Early detection of infestations could allow forest managers to mitigate outbreaks or anticipate a response to tree mortality and the potential effects on ecosystem...

  14. Hydrological Features on Subalpine Forest Zone in the East of Qinghai-Tibet Plateau (United States)

    Zhong, X.; Cheng, G.; Guo, W.


    The Hengduan mountain chains of China is situated on the east of Qinghai-Tibet Plateau with area of more than 400,000 km2. Mountains and rivers run through in north-south direction, and are collocated side by side on east-west. Elevation difference between ridges and valleys has great disparity, normally of 1000-2500m, so the vertical zones of vegetation are very distinct. Subalpine coniferous forest zone, mainly composed of fir (Abies) and spruce (Picea), is on altitude of 2800-4200m, which is a chief component of the forested area in southwest China, and an important region for water conservation of several international rivers inlcuding Nujiang River and Lancangjiang River, as well as the world-famous Changjiang River. Thus, it has both theoretical and practical significance to study hydrological process and laws of forest in this region. The study area is located at the Gongga Mountain, on the east edge of the Hengduan mountain chains. Elevation of the main peak is 7556m, and elevation difference between ridge and valley on the eastern slope is 6400m. An ecological observation station was built at altitude of 3000m on the eastern slope of Gongga Mountain in 1988, mainly for alpine ecology and forest hydrology research. Based on the analysis of 20- years observation data from this station, it is revealed that hydrological process of forest in this area has several features as follows: (1) Canopy interception of primitive fir (Abies) forest is obviously greater than other tree species, and interception rate is 30-40%. Maximal canopy interception of one-time precipitation of primitive fir forest is commonly 2-5mm. According to observation data of canopy interception, a conceptual model of canopy interception of fir forest is established: R=1.69[(1-exp(-0.41P))+0.19P (P is precipitation in mm); (2) Natural valid moisture holding capacity in layer of moss-decayed wood and leaves beneath trees is up to 5.6mm. Porosity in soil surface layer and non-capillary porosity

  15. Organic halogens in spruce forest throughfall

    DEFF Research Database (Denmark)

    Öberg, G.; Johansen, C.; Grøn, C.


    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....... 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....

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

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    Sergey Yu. Popov


    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.

  17. Comparison of the abundance and composition of litter fauna in tropical and subalpine forests (United States)

    G. Gonzalez; T.R. Seastedt


    In this study, we quantify the abundance and composition of the litter fauna in dry and wet tropical forests and north- and south-facing subalpine forests. We used the same litter species contained in litterbags across study sites to standardize for substrate conditions, and a single method of fauna extraction from the litter (Tullgren method). Fauna densities were...

  18. Morphogenetic Litter Types of Bog Spruce Forests

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    T. T. Efremova


    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

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

    NARCIS (Netherlands)

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


    [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.

  20. Effect of increasing temperatures on the distribution of spruce beetle in Engelmann spruce forests of the Interior West, USA (United States)

    R. Justin DeRose; Barbara J. Bentz; James N. Long; John D. Shaw


    The spruce beetle (Dendoctronus rufipennis) is a pervasive bark beetle indigenous to spruce (Picea spp.) forests of North America. In the last two decades outbreaks of spruce beetle have increased in severity and extent. Increasing temperatures have been implicated as they directly control beetle populations, potentially inciting endemic populations to build to...

  1. Natural tree collectives of pure oriental spruce [Picea orientalis (L.) Link] on mountain forests in Turkey. (United States)

    Ucler, Ali Omer; Yucesan, Zafer; Demirci, Ali; Yavuz, Hakki; Oktan, Ercan


    Distribution area of oriental spruce [Picea orientalis (L.) Link.] in the world is only in the north-east of Turkey and Caucasian. Because of being the semi monopoly tree with respect to its distribution and representing the upper forest line, it is necessary to analyse, evaluate and model the stand structures of oriental spruce forests in Turkey. In this research, some sampling plots were selected in timberline and treeline in the subalpine forest zone in Turkey. In these sampling plots some information about occurrence and development of the tree collectives was obtained. A total of 12 sampling plots (6 in timberline and 6 of them in treeline) were studied and horizontal and vertical stand profiles were obtained, while number of trees ranges between 2-86 in the tree collectives in treeline and in timberline 3-12. According to this, area per tree in treeline and in timberline is determined as 1.02 m2 and 3.75 m2 on an average respectively. Mean age of trees to reach breast height is 43 years in treeline sampling plots and 22 years in timberline sampling plots. According to the ratio of h (mean height) / d1.30 (diameter at breast height), stand stability values were calculated and it was determined if the stands were stable on the basis of the sampling plots. Stability values of the sampling plots changed between 33 and 75.

  2. Human disturbance provides foraging opportunities for birds in primary subalpine forest

    DEFF Research Database (Denmark)

    DuBay, Shane G.; Hart Reeve, Andrew; Wu, Yongjie


    to species that naturally occur in edge, open, or disturbed habitats. With observations and experiments we provide evidence of insectivorous birds exploiting human disturbance in primary subalpine forest in the mountains of southern China, displaying behavioral flexibility to gain novel foraging...

  3. A Comparison of Infrared Gas Analyzers Above a Subalpine Forest (United States)

    Burns, S. P.; Metzger, S.; Blanken, P.; Burba, G. G.; Swiatek, E.; Li, J.; Conrad, B.


    Infrared gas analyzers (IRGAs) are a key component in theeddy-covariance measurement of water vapor and carbon dioxide exchangebetween the surface and atmosphere. Historically, closed-path IRGAshave been used for the fast (> 10 Hz) measurement of atmospheric H2Oand CO2. In order to use them in the field, these IRGAs were typicallyhoused in temperature-controlled enclosures or buildings that weretens of meters away from the measurement location. This necessitatedthe use of long tubing and pumps to bring the air sample to the IRGAcell. Attenuation of H2O and CO2 fluctuations within the tubing was apersistent problem with such a setup, especially for H2O. As analternative, open-path IRGAs have frequently been utilized, but thekey trade-offs with the open-path design are: (i) precipitation anddew-related data gaps, and (ii) the need to account for WPL densityeffects. Over the past five years a new type of closed-path IRGA hasemerged which is weather-proof, compact, and low-maintenance. Becauseof its small size, short intake tubing can be used, which places thesampling cell close to the sonic anemometer and reduces high frequencysignal loss. Two such IRGAs are the LI-COR LI-7200 and the CampbellScientific EC155, which is part of the CPEC200 eddy covariance system.The Niwot Ridge AmeriFlux tower has used a LI-COR LI-6262 IRGA tomeasure CO2 fluxes above a subalpine forest since November, 1998.Starting in summer 2013, a LI-7200 (along with an open-path LI-7500)were deployed at 21.5 m on the AmeriFlux tower. In Fall 2013, aEC155/CPEC200 was added so that a side-by-side comparison between allfour IRGAs was possible. The preliminary results presented in ourstudy compare the CO2 and H2O mean and variance measured by each IRGA,the vertical wind statistics from three side-by-side sonicanemometers, as well as the corresponding spectra and cospectra fromthese sensors as well as other important aspects of systemperformance.

  4. Phenology of plants in relation to ambient environment in a subalpine forest of Uttarakhand, western Himalaya. (United States)

    Bisht, Vinod K; Kuniyal, Chandra P; Bhandari, Arvind K; Nautiyal, Bhagwati P; Prasad, P


    Observations on phenology of some representative trees, shrubs, under-shrubs and herbs in a subalpine forest of Uttarakhand, western Himalaya were recorded. With the commencement of favorable growth season in April, occurrence of leaf fall was indicatory growth phenomenon in Quercus semecarpifolia, Q. floribunda and Abies spectabilis. However, active vegetative growth in herbaceous species starts onward April and fruit maturation and seed dehiscence are completed from mid of September to October. In general, vegetative growth and reproductive stages in majority of the studied species seems to be dependent on adequate moisture content and also flowering and fruiting in subalpine plants correlate ambient temperature.

  5. Bleaching of leaf litter and associated microfungi in subboreal and subalpine forests. (United States)

    Hagiwara, Yusuke; Matsuoka, Shunsuke; Hobara, Satoru; Mori, Akira S; Hirose, Dai; Osono, Takashi


    Fungal decomposition of lignin leads to the whitening, or bleaching, of leaf litter, especially in temperate and tropical forests, but less is known about such bleaching in forests of cooler regions, such as boreal and subalpine forests. The purposes of the present study were to examine the extent of bleached area on the surface of leaf litter and its variation with environmental conditions in subboreal and subalpine forests in Japan and to examine the microfungi associated with the bleaching of leaf litter by isolating fungi from the bleached portions of the litter. Bleached area accounted for 21.7%-32.7% and 2.0%-10.0% of total leaf area of Quercus crispula and Betula ermanii, respectively, in subboreal forests, and for 6.3% and 18.6% of total leaf area of B. ermanii and Picea jezoensis var. hondoensis, respectively, in a subalpine forest. In subboreal forests, elevation, C/N ratio and pH of the FH layer, and slope aspect were selected as predictor variables for the bleached leaf area. Leaf mass per area and lignin content were consistently lower in the bleached area than in the nonbleached area of the same leaves, indicating that the selective decomposition of acid unhydrolyzable residue (recalcitrant compounds such as lignin, tannins, and cutins) enhanced the mass loss of leaf tissues in the bleached portions. Isolates of a total of 11 fungal species (6 species of Ascomycota and 5 of Basidiomycota) exhibited leaf-litter-bleaching activity under pure culture conditions. Two fungal species (Coccomyces sp. and Mycena sp.) occurred in both subboreal and subalpine forests, which were separated from each other by approximately 1100 km.

  6. Human-Related Forest Fires in the Subalpine Belt of the Spanish Pyrenees (United States)

    Sanjuán, Yasmina; María García-Ruiz, José; Beguería, Santiago; Serrano-Muela, María Pilar; González-Sampériz, Penélope; Valero-Garcés, Blas; Arnáez, José


    The subalpine belt of the Central Pyrenees ranges approximately between 1700 and 2200 m a.s.l. This area should be covered with dense forests of Pinus sylvestris and P. uncinata, with increasingly open formations towards the upper forest limit. At present, most of the subalpine belt is occupied with grasslands due to human-induced deforestation for enlarging the area occupied by summer pastures. Two are the most important scientific problems related to deforestation of the subalpine belt: (i) the timing of deforestation, and (ii) the geomorphic consequences of a sudden substitution of forests by grasslands. Up to now, intense deforestation is clearly recorded in regional palaeoenvironmental sequences since the Middle Ages and, traditionally, this practice was usually attributed to large fires with the purpose of balance the winter and summer pasture resources. Nevertheless, the presence of abundant remnants of prehistoric monuments (dolmens, cromlechs, tumulus) in the subalpine belt induced to think in a previous seasonal presence of human populations, most probably practicing some primitive type of transhumance. This would only be possible if part of the subalpine forests would be burnt to allow a limited expansion of grasslands, despite the consequences in the landscape of this kind of practices were not permanent in time. We present here new dates of fire occurrence from charcoal obtained from soils in the hillslopes and from lacustrine sediments. Two periods of human-induced fires have been identified: (i) between 2500 and 2000 cal. yr BP, and (ii) between 1100 and 900 cal yr BP. The consequences of deforestation can be easily observed in the landscape, particularly shallow landslide activity, gelifluction, solifluction and the rapid development of parallel incisions in the steepest slopes.

  7. Lessons from native spruce forests in Alaska: managing Sitka spruce plantations worldwide to benefit biodiversity and ecosystem services (United States)

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


    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...

  8. Atmospheric nitrous oxide uptake in boreal spruce forest soil (United States)

    Siljanen, Henri; Welti, Nina; Heikkinen, Juha; Biasi, Christina; Martikainen, Pertti


    Nitrous oxide (N2O) uptake from the atmosphere has been found in forest soils but environmental factors controlling the uptake and its atmospheric impact are poorly known. We measured N2O fluxes over growing season in a boreal spruce forest having control plots and plots with long nitrogen fertilization history. Also methane (CH4) fluxes were measured to compare the atmospheric impact of N2O and CH4fluxes. Soil chemical and physical characteristics and climatic conditions were measured as background data. Nitrous oxide consumption and uptake mechanisms were measured in complementary laboratory incubation experiments using stable isotope approaches. Gene transcript numbers of nitrous oxide reductase (nosZ) I and II genes were quantified along the incubation with elevated N2O atmosphere. The spruce forests without fertilization history showed highest N2O uptake rates whereas pine forest had low emissions. Nitrous oxide uptake correlated positively with soil moisture, high soil silt content, and low temperature. Nitrous oxide uptake varied seasonally, being highest in spring and autumn when temperature was low and water content was high. The spruce forest was sink for CH4.Methane fluxes were decoupled from the N2O fluxes (i.e. when the N2O uptake was high the CH4 uptake was low). By using GWP approach, the cooling effect of N2O uptake was on average 30% of the cooling effect of CH4 uptake in spruce forest without fertilization. Anoxic conditions promoted higher N2O consumption rates in all soils. Gene transcription of nosZ-I genes were activated at beginning of the incubation. However, atypical/clade-II nosZ was not detected. These results suggests, that also N2O uptake rates have to be considered when accounting for the GHG budget of spruce forests.

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

    Czech Academy of Sciences Publication Activity Database

    Kovářová, Marcela; Vacek, S.


    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

  10. Phenology of plants in relation to ambient environment in a subalpine forest of Uttarakhand, western Himalaya


    Bisht, Vinod K.; Kuniyal, Chandra P.; Bhandari, Arvind K.; Nautiyal, Bhagwati P.; Prasad, P.


    Observations on phenology of some representative trees, shrubs, under-shrubs and herbs in a subalpine forest of Uttarakhand, western Himalaya were recorded. With the commencement of favorable growth season in April, occurrence of leaf fall was indicatory growth phenomenon in Quercus semecarpifolia, Q. floribunda and Abies spectabilis. However, active vegetative growth in herbaceous species starts onward April and fruit maturation and seed dehiscence are completed from mid of September to Octo...

  11. Effects of forest management legacies on spruce budworm (Choristoneura fumiferana) outbreaks (United States)

    Louis-Etienne Robert; Daniel Kneeshaw; Brian R. Sturtevant


    The "silvicultural hypothesis" of spruce budworm (Choristoneura fumiferana Clem.) dynamics postulates that increasing severity of spruce budworm outbreaks over the last century resulted from forest conditions created by past management activities. Yet, definitive tests of the hypothesis remain elusive. We examined spruce budworm outbreak...

  12. Performance of the Forest Vegetation Simulator in managed white spruce plantations influenced by eastern spruce budworm in northern Minnesota (United States)

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


    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...

  13. Using maximum entropy modeling to identify and prioritize red spruce forest habitat in West Virginia (United States)

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


    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...

  14. [Characteristics of soil respiration in artificial restoration process of subalpine coniferous forest in eastern Qinghai-Tibet plateau]. (United States)

    Zhou, Fei-Fei; Lin, Bo; Liu, Qing


    By the method of infrared CO2 determination in closed dynamic chamber system, the soil respiration in natural spruce forest, and 22-, 35-and 65-year old spruce plantations in eastern Qinghai-Tibet plateau was measured in situ, and the soil heterotrophic and autotrophic respiration was differentiated by entrenchment. In the four spruce forests, soil respiration rate had a significant positive exponential correlation with the soil temperature at depth 5 cm, but less correlation with the soil moisture content at the same depth. The annual soil respiration flux was 792.08-1070.20 g C x m(-2) x a (-1), and decreased in the order of natural spruce forest > 22-year old spruce plantation > 65-year old spruce plantation >35-year old spruce plantation. The annual soil autotrophic and heterotrophic respiration fluxes were 253.36-357.05 g C x m(-2) x a(-1) and 538.69-703.82 g C x m(-2) x a(-1), respectively, and had the same variation trend as the annual soil respiration flux. The Q10 value of soil respiration in 22-, 35-, and 65-year old spruce plantations and in natural spruce forest in growth season (from Nov. 2007 to Mar. 2008) and non-growth season (from Apr. 2008 to Oct. 2008) were 4.59, 6.54, 4.77, and 3.18, and 4.17, 4.66, 3.11, and 2.74, respectively. Except that in 22-year old spruce plantation, the Q10 value was decreased with increasing restoration year, and was obviously higher in non-growth season than in growth season.

  15. Phylogeny and ecophysiology of opportunistic "snow molds" from a subalpine forest ecosystem. (United States)

    Schmidt, S K; Wilson, K L; Meyer, A F; Gebauer, M M; King, A J


    Mats of coenocytic "snow molds" are commonly observed covering the soil and litter of alpine and subalpine areas immediately following snow melt. Here, we describe the phylogenetic placement, growth rates, and metabolic potential of cold-adapted fungi from under-snow mats in the subalpine forests of Colorado. SSU rDNA sequencing revealed that these fungi belong to the zygomycete orders Mucorales and Mortierellales. All of the isolates could grow at temperatures observed under the snow at our sites (0 degrees C and -2 degrees C) but were unable to grow at temperatures above 25 degrees C and were unable to grow anaerobically. Growth rates for these fungi were very high at -2 degrees C, approximately an order of magnitude faster than previously studied cold-tolerant fungi from Antarctic soils. Given the rapid aerobic growth of these fungi at low temperatures, we propose that they are uniquely adapted to take advantage of the flush of nutrient that occurs at the soil-snow interface beneath late winter snow packs. In addition, extracellular enzyme production was relatively high for the Mucorales, but quite low for the Mortierellales, perhaps indicating some niche separation between these fungi beneath the late winter snow pack.

  16. Extensive wildfires, climate change, and an abrupt state change in subalpine ribbon forests, Colorado. (United States)

    Calder, W John; Shuman, Bryan


    Ecosystems may shift abruptly when the effects of climate change and disturbance interact, and landscapes with regularly patterned vegetation may be especially vulnerable to abrupt shifts. Here we use a fossil pollen record from a regularly patterned ribbon forest (alternating bands of forests and meadows) in Colorado to examine whether past changes in wildfire and climate produced abrupt vegetation shifts. Comparing the percentages of conifer pollen with sedimentary δ18 O data (interpreted as an indicator of temperature or snow accumulation) indicates a first-order linear relationship between vegetation composition and climate change with no detectable lags over the past 2,500 yr (r = 0.55, P changed abruptly within a century of extensive wildfires, which were recognized in a previous study to have burned approximately 80% of the surrounding 1,000 km2 landscape 1,000 yr ago when temperatures rose ~0.5°C. The vegetation change was larger than expected from the effects of climate change alone. Pollen assemblages changed from a composition associated with closed subalpine forests to one similar to modern ribbon forests. Fossil pollen assemblages then remained like those from modern ribbon forests for the following ~1,000 yr, providing a clear example of how extensive disturbances can trigger persistent new vegetation states and alter how vegetation responds to climate. © 2017 by the Ecological Society of America.

  17. Early red spruce restoration research by the Appalachian Forest Experiment Station, 1922-1954 (United States)

    James S. Rentch; Thomas M. Schuler


    This photograph (Fig. 1), taken in June of 1923 by E.S. Ship, depicts a red spruce (Picea rubens) stand with advanced reproduction near the summit of Mount Mitchell in the Pisgah National Forest of North Carolina. According to Hopkins (1899), the original extent of red spruce encompassed as much as 1,500,000 ac in the southern Appalachians; by 1895...

  18. Primary succession and dynamics of Norway spruce coastal forests on land-uplift ground moraine

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, J.S.; Jeglum, J.K. [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept of Forest Ecology


    This paper is an overview of primary succession on the rising coastlines of the Gulf of Bothnia, which emphasises Norway spruce succession and forest development and identifies topics for research. It is concluded that continuing postglacial rebound provides excellent successional sequences, and an exceptional opportunity to add new and important knowledge on original forest ecosystem development. First, long-term undisturbed forest seres, terminating in climax-like Norway spruce forest, exist. Secondly, a well-stocked, old growth spruce forest can develop on the (generally) fairly productive mesic ground-moraine sites in a short ecological time. Thirdly, undisturbed successional sequences, which go back to original soil formation, permit reconstruction of ecosystems' developmental history. Fourthly, the relationship between ground elevation and land-uplift rate facilitates estimates of ground age, and consequently permits a four-dimensional study approach. Fifthly, in view of extensive anthropogenic influence in boreal Fennoscandian forests, the few remaining natural spruce forests should be recognised and carefully documented. From our review of the literature, we conclude that present knowledge of the succession of Norway spruce on emerging shorelines, and the part played by land uplift and other factors, is fragmentary. Attention should be given to initial spruce seedling colonisation relative to factors such as sea-water level, exposure (winds, fetch), parent material, seedbed types, potential seed source (isolation), and island size. Possible multiple pathways of Norway spruce primary succession relative to temporal changes in exposure and other factors, have so far received little research effort. Attention also should be paid to the response of spruce populations to site maturation, i.e. to increasing ground age based on land-uplift rate and elevation above sea level. Finally, attention should be paid to autogenic processes in spruce-dominated stages

  19. Nocardia aciditolerans sp. nov., isolated from a spruce forest soil. (United States)

    Golinska, Patrycja; Wang, Dylan; Goodfellow, Michael


    Actinomycetes growing on acidified starch-casein agar seeded with suspensions of litter and mineral soil from a spruce forest were provisionally assigned to the genus Nocardia based upon colonial properties. Representative isolates were found to grow optimally at pH 5.5, have chemotaxonomic and morphological features consistent with their assignment to the genus Nocardia and formed two closely related subclades in the Nocardia 16S rRNA gene tree. DNA:DNA relatedness assays showed that representatives of the subclades belong to a single genomic species. The isolates were distantly associated with their nearest phylogenetic neighbour, the type strain of Nocardia kruczakiae, and were distinguished readily from the latter based on phenotypic properties. On the basis of these data it is proposed that the isolates merit recognition as a new species, Nocardia aciditolerans sp. nov. The type strain is isolate CSCA68(T) (=KACC 17155(T) = NCIMB 14829(T) = DSM 45801(T)).

  20. Mixing birch in Norway spruce stands. Impact on forest floor chemistry with implications for the buffering of acidity and the nutrition of spruce

    Energy Technology Data Exchange (ETDEWEB)

    Brandtberg, Per-Olov [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research


    This thesis focuses on the effects on forest floor chemistry of mixing birch (Betula pendula Roth. and B. pubescens Ehrh.) in Norway spruce (Picea abies (L.) Karst) stands. The mechanism behind effects and the implications they have for the nutrition of Norway spruce at an increased availability of nitrogen are also examined. Compared to pure spruce stands, mixed stands of birch and spruce had higher base saturation and lower concentrations of exchangeable and complex-bound aluminium in the forest floor. The pH did not differ between mixed and pure spruce stands except at an older site, where the pH was higher in mixed stands than in pure stands. An investigation of the fine root distribution in the H layer of the forest floor and in the upper mineral soil horizons in mixed and pure spruce stands at one site did not reveal any differences between birch and spruce as regards the distribution of fine roots. Spruce fine root distribution was not affected by the presence of birch, i.e. it was similar in mixed and pure stands. Application of radioactive isotopes or analogues of several nutrients (P, Ca and K) in the H layer and upper mineral soil around birch and spruce did not reveal a proportionally higher uptake from the mineral soil by birch. The P and K nutrition was improved for spruce when growing in mixed stands with birch. This was partly due to a lower competition for these elements by birch and partly to an increase in total available amounts of P and K by birch. However, in the mixed stands birch had a suboptimal P and K nutrition. It was concluded that birch in mixed stands with Norway spruce has a positive influence on the chemical status of the forest floor, influencing surface water quality and the ability of Norway spruce to resist negative impacts from a high deposition of atmospheric nitrogen.

  1. Ten-year variability in fluxes, meteorology, and environmental conditions at a Colorado subalpine forest site (United States)

    Burns, S. P.; Turnipseed, A.; Bowling, D. R.; Hu, J.; Monson, R. K.


    Changing meteorological and environmental conditions affect fluxes; model analysis has shown that environmental variability directly accounts for about half the interannual variability in net ecosystem exchange (NEE) of CO2 whereas the other 50% is due to biotic responses to these changing variables (Richardson et al. 2007). In our study, ten years (1998-2008) of turbulent flux measurements of heat, water vapor, and CO2 at the Niwot Ridge AmeriFlux site (Monson et al. 2002) are examined with respect to meteorological conditions (atmospheric temperature, stability, precipitation, and cloudiness) as well as changes in environmental conditions, such as snow depth and soil moisture. The typical yearly cycle and an estimate of the magnitude of year-to-year variability in the diurnal fluxes and other variables for a high-elevation subalpine forest ecosystem are presented. Wintertime ecosystem respiration has an average 30-min NEE of 0.62 μmol m-2 s-1 with an interannual range between 0.5-1 μmol m-2 s-1. Uptake of CO2 in late summer has an average NEE of -0.71 μmol m-2 s-1 with an interannual range between -0.1 to -1.5 μmol m-2 s-1. Previous studies at the Niwot Ridge AmeriFlux site have described the importance of photosynthetic photon flux density (PPFD) (Monson et al. 2002) and also growing season length (Hu et al. 2009) on NEE. Water isotope ratios analyzed by Hu et al. (2009) have shown that trees at the site primarily rely on water from snowmelt to sustain them throughout the summer; combining this result with the SIPNET model, Hu et al. conclude that there is a limited connection between summer precipitation and the cumulative annual gross primary production (GPP). We have tested this conclusion more explicitly by examining the response of NEE to specific precipitation events and the effect of extended dry periods on the diel cycle of the fluxes, CO2 mole fraction, sap flow, and other meteorological and soil variables. Additionally, we examine the connection

  2. Pervasive growth reduction in Norway spruce forests following wind disturbance.

    Directory of Open Access Journals (Sweden)

    Rupert Seidl

    Full Text Available BACKGROUND: In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of disturbance impacts and ecosystem responses is needed. With regard to the effects of strong winds--the most detrimental disturbance agent in Europe--monitoring and management has focused on structural damage, i.e., tree mortality from uprooting and stem breakage. Effects on the functioning of trees surviving the storm (e.g., their productivity and allocation have been rarely accounted for to date. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that growth reduction was significant and pervasive in a 6.79 million hectare forest landscape in southern Sweden following the storm Gudrun (January 2005. Wind-related growth reduction in Norway spruce (Picea abies (L. Karst. forests surviving the storm exceeded 10% in the worst hit regions, and was closely related to maximum gust wind speed (R(2 = 0.849 and structural wind damage (R(2 = 0.782. At the landscape scale, wind-related growth reduction amounted to 3.0 million m(3 in the three years following Gudrun. It thus exceeds secondary damage from bark beetles after Gudrun as well as the long-term average storm damage from uprooting and stem breakage in Sweden. CONCLUSIONS/SIGNIFICANCE: We conclude that the impact of strong winds on forest ecosystems is not limited to the immediately visible area of structural damage, and call for a broader consideration of disturbance effects on ecosystem structure and functioning in the context of forest management and climate change mitigation.

  3. The Response of Subalpine Vegetation to Climate Change and Bark Beetle Infestations: A Multi-Scale Interaction. (United States)

    Foster, A.; Shuman, J. K.; Shugart, H. H., Jr.; Negrón, J. F.


    Mean annual temperatures in the western United States have increased in the last few decades, and are predicted to continue warming. In the subalpine zone of the Rocky Mountains, this warming is also predicted to increase the frequency and severity of spruce beetle outbreaks. Climate change itself may affect this vegetation, potentially leading to shifts in species compositions. These forests are a crucial part of the US's carbon budget, thus it is important to analyze how climate change and bark beetles in conjunction will affect the biomass and species composition of vegetation in subalpine zone. UVAFME is an individual-based gap model that simulates biomass and species composition of a forest. This model has been quantitatively tested at various Rocky Mountain sites in the Front Range, and has been shown to accurately simulate the vegetation dynamics in the region. UVAFME has been updated with a spruce beetle subroutine that calculates the probability for beetle infestation of each tree on a plot. This probability is based on site, climate, and individual tree characteristics, such as temperature; stand structure; and tree stress level, size, and age. These governing characteristics are based on data from the US Forest Service, and other studies on spruce susceptibility and spruce beetle phenology. UVAFME is then run with multiple climate change and beetle scenarios to determine the net effect of both variables on subalpine vegetation. These results are compared among the different scenarios and to current forest inventory data. We project that increasing temperatures due to climate change will cause an increase in the frequency and severity of spruce beetle outbreaks, leading to a decrease in the biomass and dominance of Engelmann spruce. These results are an important step in understanding the possible futures for the vegetation of subalpine zone in the Rocky Mountains.

  4. Using silviculture to influence carbon sequestration in southern Appalachian spruce-fir forests (United States)

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


    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....

  5. Decomposition of soil organic matter from boreal black spruce forest: environmental and chemical controls (United States)

    Kimberly P. Wickland; Jason C. Neff


    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...

  6. Vertical structure of evapotranspiration at a spruce forest site (United States)

    Staudt, K.; Falge, E.; Serafimovich, A.; Pyles, D.; Foken, T.


    The Advanced Canopy-Atmosphere-Soil Algorithm (ACASA) was used to model the turbulent fluxes of heat, water vapor and momentum as well as the carbon dioxide exchange within and above a spruce canopy at the FLUXNET-station Waldstein-Weidenbrunnen (DE-Bay) in the Fichtelgebirge mountains in northern Bavaria, Germany. ACASA is a multilayer canopy-surface-layer model that incorporates a third-order closure method to calculate turbulent transfer within and above the canopy and was developed at the University of California, Davis. Within the EGER (ExchanGE processes in mountainous Regions) project, comprehensive micrometeorological and plant physiological measurements were performed during two intensive observation periods in fall 2007 and summer 2008. This data base allowed us to extensively test the ability of the ACASA model to simulate the exchange of energy and matter at our site. Here, the vertical structure of evapotranspiration within and above the canopy for a few days is investigated in detail. The ACASA model provides profiles of all components of evapotranspiration, such as transpiration and evaporation from the soil, and estimates the interception of precipitation and the corresponding evaporation from wet plant surfaces. Fluxes of momentum, heat, carbon dioxide and water vapor were measured with six eddy-covariance systems below, within and above the canopy on a 36 m high tower. Furthermore, xylem sapflow measurements at six heights within the canopy were performed for the determination of canopy transpiration. This combination of multilevel measurements allowed us to estimate all components of evapotranspiration of and within the spruce forest. Model results and measurements of evapotranspiration are analyzed with regard to the partitioning between its components as well as between the canopy layers. Furthermore, the ability of the ACASA model to reproduce evapotranspiration profiles for different exchange regimes of the subcanopy and the canopy is

  7. Litter Production, Decomposition, and Nutrient Release in Subalpine Forest Communities of the Northwest Himalaya

    Directory of Open Access Journals (Sweden)

    Vinod K. Bisht


    Full Text Available Production, decomposition, and release of nutrients from leaf and nonleaf litter were investigated in four subalpine forests of North-West Himalaya, India. Total annual litter fall in four communities varied from 2950.00 to 4040.00 kg ha−1 and was found significant (CD0.05 = 118.2. Decomposition of leaf litter varied from 1.82–3.5% during autumn-winter to 36.14–45.51 during summer rainy season in all stands and percent of mass loss was significantly varied in stands (CD6.00. Similarly, decomposition in nonleaf litter was varied from 0.3–1.1% during autumn-winter to 19.59–30.05% during summer rainy season and was significantly varied irrespective of seasons. However, percent decomposition of leaf litter and the values of decay constant (k were at par in all stands. Total standing state of nutrients in fresh litter as well as release of total nitrogen (N, phosphorus (P, and potassium (K in due course of decomposition (12 months was also varying significantly. The rate of nonleaf litter decomposition was significantly positively correlated with air temperature (r=0.63–0.74 in all communities. The significant correlation (r=0.85 was observed only in Rhododendron-Sorbus forest community (PRS. Study indicates that the air temperature is a major determinant for nonleaf litter decomposition in this region.

  8. A Tale of Two Forests: Simulating Contrasting Lodgepole Pine and Spruce Forest Water and Carbon Fluxes Following Mortality from Bark Beetles (United States)

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


    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

  9. Air Pollution and Forest Decline in a Spruce (Picea abies) Forest (United States)

    Schulze, E.-D.


    Symptoms of forest decline of spruce in Europe range from needle yellowing and loss to tree and stand mortality. In a study area in northeast Bavaria, West Germany, where forest decline was initially detected, exposure to high concentrations of gaseous pollutants, SO2, NOx, and ozone has had no long-lasting direct effect on needles, and pathogens have only been secondary agents. Deposition of sulfur, nitrate, and ammonium, however, have significantly modified plant nutrition and soil chemistry. Spruce roots apparently take up ammonium rather than nitrate with an antagonistic effect on uptake of Mg. Nitrate left in the soil solution is leached together with sulfate to ground water, accelerating soil acidification and decreasing Ca/Al and Mg/Al ratios in the soil solution. Soil solution chemistry affects root development, and water and nutrient uptake. Had all nutrients become equally deficient, spruce trees probably could have adjusted by retarding their growth. However, canopy uptake of atmospheric nitrogen in addition to root uptake stimulated growth and caused a nitrogen to cation imbalance to develop; this imbalance resulted in the decline symptoms.

  10. Soil, plant, and transport influences on methane in a subalpine forest under high ultraviolet irradiance

    Directory of Open Access Journals (Sweden)

    D. Baer


    Full Text Available Recent studies have demonstrated direct methane emission from plant foliage under aerobic conditions, particularly under high ultraviolet (UV irradiance. We examined the potential importance of this phenomenon in a high-elevation conifer forest using micrometeorological techniques. Vertical profiles of methane and carbon dioxide in forest air were monitored every 2 h for 6 weeks in summer 2007. Day to day variability in above-canopy CH4 was high, with observed values in the range 1790 to 1910 nmol mol−1. High CH4 was correlated with high carbon monoxide and related to wind direction, consistent with pollutant transport from an urban area by a well-studied mountain-plain wind system. Soils were moderately dry during the study. Vertical gradients of CH4 were small but detectable day and night, both near the ground and within the vegetation canopy. Gradients near the ground were consistent with the forest soil being a net CH4 sink. Using scalar similarity with CO2, the magnitude of the summer soil CH4 sink was estimated at ~1.7 mg CH4 m−2 h−1, which is similar to other temperate forest upland soils. The high-elevation forest was naturally exposed to high UV irradiance under clear sky conditions, with observed peak UVB irradiance >2 W m−2. Gradients and means of CO2 within the canopy under daytime conditions showed net uptake of CO2 due to photosynthetic drawdown as expected. No evidence was found for a significant foliar CH4 source in the vegetation canopy, even under high UV conditions. While the possibility of a weak foliar source cannot be excluded given the observed soil sink, overall this subalpine forest was a net sink for atmospheric methane during the growing season.

  11. Estimating under-canopy ablation in a subalpine red-fir forest, southern Sierra Nevada, California (United States)

    Kirchner, P. B.; Bales, R. C.; Rice, R.; Musselman, K. N.; Molotch, N. P.


    Snow ablation in forested environments is a result of the multi-component energy balance between the snow surface, radiation, topography, and vegetation. While these processes have been successfully described and modeled over small to moderate spatial extents the required data are available from few locations and existing models are computationally intensive. The problem of applying these principals to determining snow coverage for large spatial extents and frequent time steps, required by satellite observations, has not been solved. We present a simplified approach for determining a melt-out date based on modeled incident radiation, percent canopy cover, and leaf area index. This method was tested using results from instrumental data, field observations, and readily available spatial data sets by calibrating the MODIS Snow Covered Area and Grain size/albedo (MODSCAG) model from a snow-dominated site in the Wolverton basin Sequoia National Park; part of the Southern Sierra Nevada Critical Zone Observatory. The percent snow cover determined by MODSCAG from peak accumulation and melt out during the 2008 and 2009 water years were compared to ground observations of both forest gaps and under canopies. Ground based measurements indicated that under-canopy melt out of snow-covered area began earlier and ended 1 to 4 weeks after that indicated by satellite observations, which can only view snow in forest gaps. In our study ablation rates, snow cover duration, leaf area index, canopy closure, and Incoming short and long wave radiation were measured on north and southeast facing plots in a subalpine red fir forest. Results from regression analysis yield an R2=0.99 between modeled and measured short wave radiation and an R2=0.82 between leaf area index and the difference between open and under canopy thermal infrared radiation. Canopy cover and leaf area index were also found to be good predictors of observed melt rates and the melt off date of snow under tree canopies. This

  12. Patterns of total ecosystem carbon storage with changes in soil temperature in boreal black spruce forests (United States)

    E.S. Kane; J.G. Vogel


    To understand how carbon (C) pools in boreal ecosystems may change with warming, we measured above- and belowground C pools and C increment along a soil temperature gradient across 16 mature upland black spruce (Picea mariana Mill. [B•S.P]) forests in interior Alaska. Total spruce C stocks (stand and root C) increased from 1.3 to 8.5 kg C m

  13. [Dynamics of species diversity in artificial restoration process of subalpine coniferous forest]. (United States)

    Wu, Yan; Liu, Qing; He, Hai; Lin, Bo


    Through plot investigation and by adopting the concept of space as a substitute for time, the developments of species diversity of trees, shrubs and herbaceous plants in subalpine coniferous plantations at different restoration stages were studied, and the correlation coefficients of species in each layer were discussed. The results indicated that in the restoration process, the species richness, diversity and evenness in subalpine coniferous plantations were gradually increased in a fluctuating way. The restoration process of Picea asperata plantations showed a tendency of development that in favor of resuming species diversity. The indices of species richness (species number and Margalef index) and species diversity (Shannon-Wiener index and Simpson index) of trees increased rapidly from the early stages of plantation establishment to the stage of canopy closing (about 30 yr of stand age) and then presented a tendency of decrease with some slight fluctuations, while the index of species evenness showed a periodical rising trend. For the shrub layer, the indices of species richness (Simpson index and Macintosh index) gradually increased with increasing restoration years, whereas the indices of species diversity (Shannon-Wiener index) decreased in the early stages, sharply increased during the stages of canopy closing, and then slowly decreased, which exhibited a tendency of high-->low-->high. In the layer of herbaceous plants, the indices of species richness (Margalef index and number of species) and species diversity (Simpson index, Macintosh index and Shannon-Wiener index) presented a trend of decrease in the early stages of plantations establishment to canopy closing and increased later on. During this process, herbaceous species and their life forms changed greatly, with shade tolerant species gradually substituting the intolerant species. Among the plantations of different stand ages, the average correlation coefficients of trees, shrubs and herbaceous

  14. Use of passive UAS imaging to measure biophysical parameters in a southern Rocky Mountain subalpine forest (United States)

    Caldwell, M. K.; Sloan, J.; Mladinich, C. S.; Wessman, C. A.


    Unmanned Aerial Systems (UAS) can provide detailed, fine spatial resolution imagery for ecological uses not otherwise obtainable through standard methods. The use of UAS imagery for ecology is a rapidly -evolving field, where the study of forest landscape ecology can be augmented using UAS imagery to scale and validate biophysical data from field measurements to spaceborne observations. High resolution imagery provided by UAS (30 cm2 pixels) offers detailed canopy cover and forest structure data in a time efficient and inexpensive manner. Using a GoPro Hero2 (2 mm focal length) camera mounted in the nose cone of a Raven unmanned system, we collected aerial and thermal data monthly during the summer 2013, over two subalpine forests in the Southern Rocky Mountains in Colorado. These forests are dominated by lodgepole pine (Pinus ponderosae) and have experienced insect-driven (primarily mountain pine beetle; MPB, Dendroctonus ponderosae) mortality. Objectives of this study include observations of forest health variables such as canopy water content (CWC) from thermal imagery and leaf area index (LAI), biomass and forest productivity from the Normalized Difference Vegetation Index (NDVI) from UAS imagery. Observations were, validated with ground measurements. Images were processed using a combination of AgiSoft Photoscan professional software and ENVI remote imaging software. We utilized the software Leaf Area Index Calculator (LAIC) developed by Córcoles et al. (2013) for calculating LAI from digital images and modified to conform to leaf area of needle-leaf trees as in Chen and Cihlar (1996) . LAIC uses a K-means cluster analysis to decipher the RGB levels for each pixel and distinguish between green aboveground vegetation and other materials, and project leaf area per unit of ground surface area (i.e. half total needle surface area per unit area). Preliminary LAIC UAS data shows summer average LAI was 3.8 in the most dense forest stands and 2.95 in less dense

  15. Trace elements in sub-alpine forest soils on the eastern edge of the Tibetan Plateau, China (United States)

    Wang, Xiaodan; Cheng, Genwei; Zhong, Xianghao; Li, Mai-He


    Industrial development has increased fast in China during the last decades. This has led to a range of environmental problems. Deposition of trace elements to forest ecosystems via the atmosphere is one potential problem. In this paper, we report the results from a pilot study where the trace element levels of the sub-alpine forest soils on the eastern edge of the Tibetan Plateau have been measured. Possible relationships between soil properties and trace element concentrations have also been investigated. The obtained concentrations (mg kg-1) were boron (B) 48.06-53.70, molybdenum (Mo) 1.53-2.26, zinc (Zn) 68.18-79.53, copper (Cu) 36.81-42.44, selenium (Se) 0.33-0.49, cadmium (Cd) 0.16-0.29, lead (Pb) 25.80-30.71, chromium (Cr) 96.10-110.08, nickel (Ni) 30.16-45.60, mercury (Hg) 0.05-0.11, and arsenic (As) 3.09-4.17. With a few exceptions, the element concentration can be characterized as low in the investigated sub-alpine forest soils. No clear differences in trace element levels were found between topsoil and subsoil samples, indicating that the atmospheric deposition of trace element has been low. The soil parent material plays a key role to determine trace element levels. Soil properties, including pHw, organic carbon (OC), clay fraction, cation-exchange capacity (CEC), total iron (Fe), and total aluminum (Al) concentrations were related to trace element concentration using correlation analysis. Total Fe and Al showed the strongest relationships with concentrations of most trace elements in the sub-alpine forest soils. PCA analyses indicated that a significant increase in the number of cars with the fast development of local tourism may result in higher Pb concentration in the future.

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

    Directory of Open Access Journals (Sweden)

    R. D. Vasilishyn


    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.

  17. Long-term landscape changes in a subalpine spruce-fir forest in central Utah, USA (United States)

    Jesse L. Morris; R. Justin DeRose; Andrea R. Brunelle


    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....

  18. Long-term reactive nitrogen loading alters soil carbon and microbial community properties in a subalpine forest ecosystem (United States)

    Boot, Claudia M; Hall, Ed K.; Denef, Karolien; Baron, Jill S.


    Elevated nitrogen (N) deposition due to increased fossil fuel combustion and agricultural practices has altered global carbon (C) cycling. Additions of reactive N to N-limited environments are typically accompanied by increases in plant biomass. Soil C dynamics, however, have shown a range of different responses to the addition of reactive N that seem to be ecosystem dependent. We evaluated the effect of N amendments on biogeochemical characteristics and microbial responses of subalpine forest organic soils in order to develop a mechanistic understanding of how soils are affected by N amendments in subalpine ecosystems. We measured a suite of responses across three years (2011–2013) during two seasons (spring and fall). Following 17 years of N amendments, fertilized soils were more acidic (control mean 5.09, fertilized mean 4.68), and had lower %C (control mean 33.7% C, fertilized mean 29.8% C) and microbial biomass C by 22% relative to control plots. Shifts in biogeochemical properties in fertilized plots were associated with an altered microbial community driven by reduced arbuscular mycorrhizal (control mean 3.2 mol%, fertilized mean 2.5 mol%) and saprotrophic fungal groups (control mean 17.0 mol%, fertilized mean 15.2 mol%), as well as a decrease in N degrading microbial enzyme activity. Our results suggest that decreases in soil C in subalpine forests were in part driven by increased microbial degradation of soil organic matter and reduced inputs to soil organic matter in the form of microbial biomass.

  19. Short-term effects of forest disturbances on soil nematode communities in European mountain spruce forests. (United States)

    Čerevková, A; Renčo, M; Cagáň, L


    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.

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

    Directory of Open Access Journals (Sweden)

    Adrian Indreica


    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.

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

    DEFF Research Database (Denmark)

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


    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 ...

  2. Postfire seed rain of black spruce, a semiserotinous conifer, in forests of interior Alaska (United States)

    Jill Johnstone; Leslie Boby; Emily Tissier; Michelle Mack; Dave Verbyla; Xanthe. Walker


    The availability of viable seed can act as an important constraint on plant regeneration following disturbance. This study presents data on seed quantity and quality for black spruce (Picea mariana (Mill.) B.S.P.), a semiserotinous conifer that dominates large areas of North American boreal forest. We sampled seed rain and viability for 2 years...

  3. Foliar and soil chemistry at red spruce sites in the Monongahela National Forest (United States)

    Stephanie J. Connolly


    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.

  4. Relation of heart rots to mortality of red spruce in the Green Mountain National Forest (United States)

    Paul V. Mook; Harold G. Eno


    Several years ago, old-growth red spruce at high elevations in the Green Mountain National Forest were observed to be dying. Entomologists and pathologists who examined the affected area found no insect or fungus that was obviously causing the deaths. However, many of the dead and dying trees were butt-rotted by the fungus Polyporus borealis. Though it seemed unlikely...

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

    Directory of Open Access Journals (Sweden)

    E. M. Lapteva


    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.

  6. Water use patterns of three species in subalpine forest, Southwest China: the deuterium isotope approach (United States)

    Qing Xu; Harbin Li; Jiquan Chen; Jiquan Cheng; Xiaoli Cheng; Shirong Liu; Shuqing An


    Determination of water sources of plant species in a community is critical for understanding the hydrological processes and their importance in ecosystem functions. Such partitioning of plant xylem water into specific sources (i.e. precipitation, groundwater) can be achieved by analyzing deuterium isotopic composition (δD) values for source waters. A subalpine dark...

  7. Establishment and growth of white spruce on a boreal forest floodplain: interactions between microclimate and mammalian herbivory (United States)

    Amy C. Angell; Knut. Kielland


    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...

  8. Responses Of Subalpine Conifer Seedling Germination And Survival To Soil Microclimate In The Alpine Treeline Warming Experiment (United States)

    Castanha, C.; Moyes, A. B.; Torn, M. S.; Germino, M. J.; Kueppers, L. M.


    At Niwot Ridge, Colorado, we used common gardens and climate manipulations to investigate potential subalpine tree species range shifts due to climate change. In Fall 2009 we harvested seed from local populations of limber pine and Englemann spruce, which we sowed in 3 experimental sites spanning an elevation gradient from lower subalpine forest (3080m asl), to the upper subalpine treeline ecotone (3400m asl), to the alpine tundra (3550m asl). In October we turned on overhead infrared heaters designed to increase growing season surface soil temperature by 4-5°C, and following snowmelt in 2010 we crossed this heating treatment with manual watering, adding 3mm of water each week. Here we report on the species, site, and treatment effects on seedling emergence and survival as mediated by snowmelt date, soil temperature, and soil moisture. Depending on the site and plot, heating accelerated germination by 1 to 4 weeks. Germination degree days (heat accumulation required for seed germination) were greater for pine than for spruce and greater in drier plots. Seedling survival was explained by date of emergence, with older seedlings more likely to survive the season. Survival was also explained by drought degree days -- the number of days below critical soil moisture thresholds compounded by high temperature -- with lower thresholds for spruce than for pine. Our preliminary results indicate that a warmer environment will stimulate germination for both species, but that, survival - especially for spruce - will be critically modulated by summer soil moisture.

  9. Impacts of fire on non-native plant recruitment in black spruce forests of interior Alaska.

    Directory of Open Access Journals (Sweden)

    Xanthe J Walker

    Full Text Available Climate change is expected to increase the extent and severity of wildfires throughout the boreal forest. Historically, black spruce (Picea mariana (Mill. B.S.P. forests in interior Alaska have been relatively free of non-native species, but the compounding effects of climate change and an altered fire regime could facilitate the expansion of non-native plants. We tested the effects of wildfire on non-native plant colonization by conducting a seeding experiment of non-native plants on different substrate types in a burned black spruce forest, and surveying for non-native plants in recently burned and mature black spruce forests. We found few non-native plants in burned or mature forests, despite their high roadside presence, although invasion of some burned sites by dandelion (Taraxacum officinale indicated the potential for non-native plants to move into burned forest. Experimental germination rates were significantly higher on mineral soil compared to organic soil, indicating that severe fires that combust much of the organic layer could increase the potential for non-native plant colonization. We conclude that fire disturbances that remove the organic layer could facilitate the invasion of non-native plants providing there is a viable seed source and dispersal vector.

  10. Development of spruce-fir stands following spruce beetle outbreaks (United States)

    J. M. Schmid; T. E. Hinds


    Logged and unlogged stands of Engelmann spruce-subalpine fir were evaluated in spruce beetle outbreak areas infested about 15, 25, 50, and 100 years ago. Seedling regeneration was generally adequate except in heavily logged areas, although seedlings were often damaged, apparently by animals. Species composition was dramatically altered in favor of fir in the unlogged...

  11. Airflow patterns in a small subalpine basin (United States)

    G. Wooldridge; R. Musselman; B. Connell; D. Fox


    A study of mean wind speeds and directions has been completed in the Snowy Range of Southern Wyoming, U.S.A. It was conducted in a subalpine ecosystem at an altitude of 3 200 m to 3 400 m above sea level during the summers of 1988 and 1989. Indexes of deformation and axes of asymmetry due to wind shaping of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies...

  12. Can We Use Forest Inventory Mapping as a Coarse Filter in Ecosystem Based Management in the Black Spruce Boreal Forest?

    Directory of Open Access Journals (Sweden)

    Chafi Chaieb


    Full Text Available Forest inventory mapping is used worldwide to describe forests at a large spatial scale via the delimitation of portions of the landscape that are structurally homogeneous. Consequently, there is a significant amount of descriptive forest data in forest inventory maps, particularly with the development of ecosystem classification, which represents a significant potential for use in ecosystem based management. With this study we propose to test whether forest inventory maps can be used to describe not only stand characteristics but also dynamic processes. The results indicate that stand types identifiable in forest inventory maps do not in fact represent unique developmental stages, but rather confound stands at multiple developmental stages that may be undergoing different ecological processes. The reasons for this are linked to both the interaction between succession, fire severity and paludification. Finally, some aspects of the process of forest inventory mapping itself contribute to the disjunction between forest types and forest succession. Given the low similarity between spruce mapping types and their actual description following forest inventories, it would be too ambitious to infer the dynamic aspects of spruce forest by map units.

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

    Directory of Open Access Journals (Sweden)

    Šljukić Biljana


    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

  14. Different mixtures of Norway spruce, silver fir, and European beech modify competitive interactions in central European mature mixed forests

    National Research Council Canada - National Science Library

    Tobin, Brian; Larocque, Guy R; Petráš, Rudolf; Bosela, Michal; Šebeň, Vladimír


    ...–spruce forests, mostly because of a lack of long-term experimental research. In the 1960s, long-term sample plots were established in the Western Carpathians to develop region-specific yield models...

  15. Autotrophic and Heterotrophic Controls over Winter Soil Carbon Cycling in a Subalpine Forest Ecosystem (United States)

    Monson, R. K.; Scott-Denton, L. E.; Lipson, D. A.; Weintrub, M. N.; Rosenstiel, T. N.; Schmidt, S. K.; Williams, M. W.; Burns, S. P.; Delany, A. E.; Turnipseed, A. A.


    that interannual variation in winter ecosystem respiration is positively correlated to interannual variation in the spring snow depth. Years with a with a deeper spring snow pack exhibited higher soil temperatures, and concomitantly higher soil respiration rates. Given the recently reported decadal-scale trend in decreasing snow pack in the Western U.S., which is coupled to warm climate anomalies, our observations indicate the potential for higher wintertime soil carbon sequestration due to lower winter ecosystem respiration rates in subalpine forests. Our studies of processes beneath the winter snow pack demonstrate that contrary to previous assumptions, winter biogeochemical processing of soil organic matter is an important component of ecosystem carbon budgets. Despite low temperatures and an inactive plant rhizosphere, winter microbial communities and exoenzymes appear to be active, carbon substrates appear to be in relatively high abundance and soil respiration rates appear to be sensitive to seasonal and interannual winter climate variability.

  16. [Effects of snow pack on soil nitrogen transformation enzyme activities in a subalpine Abies faxioniana forest of western Sichuan, China]. (United States)

    Xiong, Li; Xu, Zhen-Feng; Wu, Fu-Zhong; Yang, Wan-Qin; Yin, Rui; Li, Zhi-Ping; Gou, Xiao-Lin; Tang, Shi-Shan


    This study characterized the dynamics of the activities of urease, nitrate reductase and nitrite reductase in both soil organic layer and mineral soil layer under three depths of snow pack (deep snowpack, moderate snowpack and shallow snowpack) over the three critical periods (snow formed period, snow stable period, and snow melt period) in the subalpine Abies faxoniana forest of western Sichuan in the winter of 2012 and 2013. Throughout the winter, soil temperature under deep snowpack increased by 46.2% and 26.2%, respectively in comparison with moderate snowpack and shallow snowpack. In general, the three nitrogen-related soil enzyme activities under shallow snowpack were 0.8 to 3.9 times of those under deep snowpack during the winter. In the beginning and thawing periods of seasonal snow pack, shallow snowpack significantly increased the activities of urease, nitrate and nitrite reductase enzyme in both soil organic layer and mineral soil layer. Although the activities of the studied enzymes in soil organic layer and mineral soil layer were observed to be higher than those under deep- and moderate snowpacks in deep winter, no significant difference was found under the three snow packs. Meanwhile, the effects of snowpack on the activities of the measured enzymes were related with season, soil layer and enzyme type. Significant variations of the activities of nitrogen-related enzymes were found in three critical periods over the winter, and the three measured soil enzymes were significantly higher in organic layer than in mineral layer. In addition, the activities of the three measured soil enzymes were closely related with temperature and moisture in soils. In conclusion, the decrease of snow pack induced by winter warming might increase the activities of soil enzymes related with nitrogen transformation and further stimulate the process of wintertime nitrogen transformation in soils of the subalpine forest.

  17. Complex terrain alters temperature and moisture limitations of forest soil respiration across a semiarid to subalpine gradient (United States)

    Berryman, Erin Michele; Barnard, H.R.; Adams, H.R.; Burns, M.A.; Gallo, E.; Brooks, P.D.


    Forest soil respiration is a major carbon (C) flux that is characterized by significant variability in space and time. We quantified growing season soil respiration during both a drought year and a nondrought year across a complex landscape to identify how landscape and climate interact to control soil respiration. We asked the following questions: (1) How does soil respiration vary across the catchments due to terrain-induced variability in moisture availability and temperature? (2) Does the relative importance of moisture versus temperature limitation of respiration vary across space and time? And (3) what terrain elements are important for dictating the pattern of soil respiration and its controls? Moisture superseded temperature in explaining watershed respiration patterns, with wetter yet cooler areas higher up and on north facing slopes yielding greater soil respiration than lower and south facing areas. Wetter subalpine forests had reduced moisture limitation in favor of greater seasonal temperature limitation, and the reverse was true for low-elevation semiarid forests. Coincident climate poorly predicted soil respiration in the montane transition zone; however, antecedent precipitation from the prior 10 days provided additional explanatory power. A seasonal trend in respiration remained after accounting for microclimate effects, suggesting that local climate alone may not adequately predict seasonal variability in soil respiration in montane forests. Soil respiration climate controls were more strongly related to topography during the drought year highlighting the importance of landscape complexity in ecosystem response to drought.

  18. Multi-scale patterns of subalpine fir mortality are driven by complex interactions among broad-scale climate, local topography, stand structure, and tree characteristics (United States)

    Harvey, B. J.; Andrus, R. A.; Orrego, A.; Battaglia, M.; Negrón, J. F.; Veblen, T. T.


    Recent tree mortality events across much of western North America have been associated with warming temperatures and elevated drought stress, which can interact with forest stand-structure and tree vigor to drive outbreaks of native insect species. Although cross-scale interactions among drivers of tree-mortality events have been described for some beetle species (e.g., mountain pine beetle or spruce beetle) and their hosts (lodgepole pine and Engelmann spruce), less is known about how drivers at different scales interact to kill subalpine fir (Abies lasiocarpa) in a phenomenon simply dubbed "subalpine fir mortality" or "subalpine fir decline." Understanding the fate of subalpine fir is important, however, because this is commonly the tree species expected to establish and exhibit growth releases following outbreaks of mountain pine beetle or spruce beetle. In this study, we use three decades of field and remote data that span spatial scales from individual trees to sub-continental ecoregions to explore factors associated with subalpine fir mortality and how drivers interact across scales. Between 1991 and 2015, >5 million hectares (ha) of subalpine forest in the US Rocky Mountains have been affected by subalpine fir mortality. At the eco-region scale (1,000s of km), mortality was temporally associated with increases in regional drought stress, suggesting that climate is an important broad-scale driver. However, at the eco-region, landscape, and stand scales (several km to sub ha), mortality was greatest in cooler/wetter topographic locations and in areas with greater pre-mortality subalpine fir dominance. Conversely, mortality was lowest for fir trees in warmer/drier topographic locations and in areas of lesser pre-mortality subalpine fir dominance. This suggests that topographically driven differences in stand structure drive mortality dynamics at meso-scales and moderate the broad-scale influence of climate. Finally, at the tree and tree-neighborhood scale

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

    DEFF Research Database (Denmark)

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


    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...... of chloroform is suggested, whereas for the other compounds anthropogenic sources are assumed. The addition of trichloroacetic acid to the soil increased the release of chloroform from the soil. It is, therefore, suggested that trichloroacetic acid also contributed to the formation of chloroform. Under...... the experimental conditions, the spruce forest soil released chloroform concentrations corresponding to a rate of 12 mu g m(-2) day(-1). Data on chloroform production rates are presented and compared with literature results, and possible formation mechanisms for chloroform are discussed. (C) 2000 Elsevier Science...

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

    Energy Technology Data Exchange (ETDEWEB)

    Zapletal, Milos, E-mail: [Ekotoxa s.r.o. - Centre for Environment and Land Assessment, Oticka 37, 746 01 Opava (Czech Republic); Silesian University at Opava, Faculty of Philosophy and Science, Masarykova 37, 746 01 Opava (Czech Republic); Cudlin, Pavel [Institute of Systems Biology and Ecology of the AS CR, v.v.i., Na Sadkach 7, 37005 Ceske Budejovice (Czech Republic); Chroust, Petr [Ekotoxa s.r.o. - Centre for Environment and Land Assessment, Oticka 37, 746 01 Opava (Czech Republic); Urban, Otmar; Pokorny, Radek [Institute of Systems Biology and Ecology of the AS CR, v.v.i., Porici 3b, 60300 Brno (Czech Republic); Edwards-Jonasova, Magda [Institute of Systems Biology and Ecology of the AS CR, v.v.i., Na Sadkach 7, 37005 Ceske Budejovice (Czech Republic); Czerny, Radek; Janous, Dalibor; Taufarova, Klara [Institute of Systems Biology and Ecology of the AS CR, v.v.i., Porici 3b, 60300 Brno (Czech Republic); Vecera, Zbynek; Mikuska, Pavel [Institute of Analytical Chemistry of the AS CR, v.v.i., Veveri 97, 60200 Brno (Czech Republic); Paoletti, Elena [Institute of Plant Protection, National Research Council of Italy, via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)


    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{sup -1} and 0.36 cm s{sup -1} by the gradient method and the deposition model, respectively. Measured and modelled non-stomatal uptake was around 0.2 cm s{sup -1}. In addition, net ecosystem production (NEP) was measured by using Eddy Covariance and correlations with O{sub 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{sub 3} imply a reduction of NEP. > Deposition and stomatal uptake of O{sub 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.

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

    Directory of Open Access Journals (Sweden)

    Monika Budzáková


    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

  2. Tree age, disturbance history, and carbon stocks and fluxes in subalpine Rocky Mountain forests (United States)

    J.B. Bradford; R.A. Birdsey; L.A. Joyce; M.G. Ryan


    Forest carbon stocks and fluxes vary with forest age, and relationships with forest age are often used to estimate fluxes for regional or national carbon inventories. Two methods are commonly used to estimate forest age: observed tree age or time since a known disturbance. To clarify the relationships between tree age, time since disturbance and forest carbon storage...


    Directory of Open Access Journals (Sweden)

    O. I. Evstigneev


    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

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

    Robert H. Ruth; Carl M. Berntsen


    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...

  5. Tree plant organic matter stocks in spruce green moss Piceetum hylocomiosum and pine lichen Pinetum cladinosum forest communities after windfall

    Directory of Open Access Journals (Sweden)

    A. V. Manov


    Full Text Available Accumulation of organic matter in spruce green moss Piceetum hylocomiosum and pine lichen Pinetum cladinosum forest communities after windfall was investigated. Phytomass of Piceetum hylocomiosum stand is 51.8 t • ha-1, and Pinetum cladinosum stand is 7.5 t • ha-1. Phytomass in the disturbed stands is 3.5 times less than in undisturbed spruce forest and 15 times less than in undisturbed pine forest. The undergrowth accumulates 2.8 t • ha-1 in spruce forest, and 0.9 t • ha-1 in pine forest after windfall. Number of trees, volume of wood, stock of organic matter was determined in coarse woody debris subject to decay class. Most of the dead trees (77–97 % belong to the second decay class. Reduced competition for light and mineral nutrients influences the intensity of organic matter accumulation by tree plants. We detected that increasing radial growth of spruce and fir began before windfall. This demonstrates the stand drying. However, maximal rate of annual ring increment (2.03–2.17 mm for spruce and 3.98–4.07 mm for fir was observed in 2009–2010 years. After windfall radial growth of undergrowth increased 2 times in Piceetum hylocomiosum and 7.7 times in Pinetum cladinosum. Height increment of spruce and fir understorey increased 2.2–2.6 times in spruce forest. As compared with undisturbed ecosystems height increment of pine understorey is 1.2–2.0 times higher on windbreak in Pinetum cladinosum.

  6. Implementing Continuous Cover Forestry in Planted Forests: Experience with Sitka Spruce (Picea Sitchensis in the British Isles

    Directory of Open Access Journals (Sweden)

    William L. Mason


    Full Text Available Planted forests of Sitka spruce, a non-native species from north-west America, are the major forest type in Great Britain and Ireland. Standard management involves even-aged stands, rotations of 40–50 years and a patch clear-felling system with artificial regeneration. However, forest policies support managing these forests for multifunctional objectives with increased diversity of species composition and stand structure. Continuous cover forestry (CCF is an alternative silvicultural approach used to provide such diversity, but the amount of CCF forest is under 10% of the forest area, and less in Sitka spruce forests; This paper reviews research carried out in the last two decades to support the implementation of CCF in Sitka spruce planted forests; Stand structures and microclimate favouring natural regeneration are understood. Harvesting systems have been adapted for use in CCF stands, a single-tree growth model has been calibrated, comparative costs and revenues have been determined, and operational trials established. The interaction between thinning and wind stability in irregular stands is problematic, together with the lack of suitable species for growing in mixture with Sitka spruce; Introduction of an alternative silvicultural approach may take decades and must overcome technical challenges and cultural resistance.

  7. Topographic controls on black carbon accumulation in Alaskan black spruce forest soils: implications for organic matter dynamics (United States)

    E.S. Kane; W.C. Hockaday; M.R. Turetsky; C.A. Masiello; D.W. Valentine; B.P. Finney; J.A. Badlock


    There is still much uncertainty as to how wildfire affects the accumulation of burn residues (such as black carbon [BC]) in the soil, and the corresponding changes in soil organic carbon (SOC) composition in boreal forests. We investigated SOC and BC composition in black spruce forests on different landscape positions in Alaska, USA. Mean BC stocks in surface mineral...

  8. Effects of bark beetle attack on canopy fuel flammability and crown fire potential in lodgepole pine and Engelmann spruce forests (United States)

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


    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...

  9. Effect of species composition on carbon and nitrogen stocks in forest floor and mineral soil in Norway spruce and European beech mixed forests (United States)

    Andivia, Enrique; Rolo, Víctor; Jonard, Mathieu; Formánek, Pavel; Ponette, Quentin


    Management of existing forests has been identified as the main strategy to enhance carbon sequestration and to mitigate the impact of climate change on forest ecosystems. In this direction, the conversion of Norway spruce monospecific stands into mixed stands by intermingling individuals of European beech is an ongoing trend in adaptive forest management strategies, especially in Central Europe. However, studies assessing the effect of changes in tree species composition on soil organic carbon (SOC) and nitrogen stocks are still scarce and there is a lack of scientific evidence supporting tree species selection as a feasible management option to mitigate the effects of predicted future climatic scenarios. We compared C and N stocks in the forest floor (litter and humus) and the top 10 cm of mineral soil in two monospecific stands of Norway spruce and European beech and in a mixed stand of both species. The effect of tree species composition on the C and N stocks and its spatial distribution was evaluated based on litterfall, root production, elevation and canopy opening, and by using a combination of modelling and geostatistical techniques. C stock was highest in the Norway spruce and the mixed stands, while N stock was highest in the mixed stand and lowest under European beech, with intermediate values in the Norway spruce stand. Each forest type showed differences in forest floor properties, suggesting that species composition is an important factor governing forest floor characteristics, including C and N stocks. The distribution of C and N stocks between forest soil layers was different for each forest type. C and N stocks were highest in the hummus layer under Norway spruce, whereas both stocks were lowest in the European beech stand. On the other hand, the mixed stand showed the highest C and N accumulation in the uppermost mineral soil layer, while the monospecific stands showed similar values. Litterfall was the main contribution to C and N stocks of the

  10. Biogenic nitric oxide emission from a spruce forest soil in mountainous terrain (United States)

    Falge, Eva; Bargsten, Anika; Behrendt, Thomas; Meixner, Franz X.


    The process-based spatial simulation model SVAT-CN was used to estimate biogenic nitric oxide (NO) emission by soils of a Norway spruce forest (Weidenbrunnen) in the Fichtelgebirge, Germany. SVAT-CN core is a combination of a multiple-layer soil water balance model and a multi-layered canopy gas exchange model. The soil modules comprise a flexible hybrid between a layered bucket model and classical basic liquid flow theory. Further soil processes include: heat transport, distribution of transpiration demand proportionally to soil resistance, reduction of leaf physiological parameters with limiting soil moisture. Spruce forest soils usually are characterized by a thick organic layer (raw humus), with the topmost centimetres being the location where most of the biogenic NO is produced. Within individual spruce forest stands the understory might be composed of patches characterized by different species (e.g. Vaccinium myrtillus, Picea abies, Deschampsia caespitosa), and NO production potentials. The effect of soil physical and chemical parameters and understory types on NO emission from the organic layer was investigated in laboratory incubation and fumigation experiments on soils sampled below the various understory covers found at the Weidenbrunnen site. Results from the laboratory experiments were used to parameterize multi-factorial regression models of soil NO emission with respect to its response to soil temperature and moisture. Parameterization of the spatial model SVAT-CN includes horizontal heterogeneity of over- and understory PAI, understory species distribution, soil texture, bulk density, thickness of organic layer. Simulations are run for intensive observations periods of 2007 and 2008 of the EGER (ExchanGE processes in mountainous Regions) project, a late summer/fall and an early summer period, providing estimates for different understory types (young spruce, blueberry, grass, and moss/litter patches). Validation of the model is being carried out at

  11. Species composition influences management outcomes following mountain pine beetle in lodgepole pine-dominated forests (United States)

    Kristen Pelz; C. C. Rhoades; R. M. Hubbard; M. A. Battaglia; F. W. Smith


    Mountain pine beetle outbreaks have killed lodgepole pine on more than one million hectares of Colorado and southern Wyoming forest during the last decade and have prompted harvest operations throughout the region. In northern Colorado, lodgepole pine commonly occurs in mixed stands with subalpine fir, Engelmann spruce, and aspen. Variation in tree species composition...

  12. Thirty Years of Change in Subalpine Forest Cover from Landsat Image Analysis in the Sierra Nevada Mountains of California (United States)

    Potter, Christopher


    Landsat imagery was analyzed to understand changes in subalpine forest stands since the mid-1980s in the Sierra-Nevada region of California. At locations where long-term plot measurements have shown that stands are becoming denser in the number of small tree stems (compared to the early 1930s), the 30-year analysis of Landsat greenness index (NDVI) indicated that no consistent increases in canopy leaf cover have occurred at these same locations since the mid-1980s. Interannual variations in stand NDVI closely followed snow accumulation amounts recorded at nearby stations. In contrast, at eastern Sierra whitebark pine stand locations where it has been observed that widespread tree mortality has occurred, decreasing NDVI trends over the past 5-10 years were consistent with rapid loss of forest canopy cover. Landsat imagery was further analyzed to understand patterns of post-wildfire vegetation recovery, focusing on high burn severity (HBS) patches within burned areas dating from the late 1940s. Analysis of landscape metrics showed that the percentage of total HBS area comprised by the largest patch of recovered woody cover was relatively small in all fires that occurred since 1995, but increased rapidly with time since fire. Patch complexity of recovered woody cover decreased notably after more than 50 years of regrowth, but was not readily associated with time for fires that occurred since the mid 1990s. The aggregation level of patches with recovery of woody cover increased steadily with time since fire. The study approach using satellite remote sensing can be expanded to assess the consequences of stand-replacing wildfires in all forests of the region.

  13. Modelling black spruce primary production and carbon allocation in the Quebec boreal forest (United States)

    Gennaretti, Fabio; Guiot, Joel; Berninger, Frank; Boucher, Etienne; Gea-Izquierdo, Guillermo


    Boreal ecosystems are crucial carbon stores that must be urgently quantified and preserved. Their future evolution is extremely important for the global carbon budget. Here, we will show the progresses achieved with the MAIDEN forest ecophysiological model in simulating carbon fluxes of black spruce (Picea mariana (Mill.) B.S.P.) forests, the most representative ecosystem of the North American boreal biome. Starting from daily minimum-maximum air temperature, precipitation and CO2 atmospheric concentration, MAIDEN models the phenological (5 phenological phases are simulated each year) and meteorological controls on gross primary production (GPP) and carbon allocation to stem. The model is being calibrated on eddy covariance and tree-ring data. We will discuss the model's performance and the modifications introduced in MAIDEN to adapt the model to temperature sensitive forests of the boreal region.

  14. Climate drivers of bark beetle outbreak dynamics in Norway spruce forests

    DEFF Research Database (Denmark)

    Marini, Lorenzo; Økland, Bjørn; Jönsson, Anna Maria


    Bark beetles are among the most devastating biotic agents affecting forests globally and several species are expected to be favored by climate change. Given the potential interactions of insect outbreaks with other biotic and abiotic disturbances, and the potentially strong impact of changing...... disturbance regimes on forest resources, investigating climatic drivers of destructive bark beetle outbreaks is of paramount importance. We analyzed 17 time-series of the amount of wood damaged by Ips typographus, the most destructive pest of Norway spruce forests, collected across 8 European countries...... in the last three decades. We aimed to quantify the relative importance of key climate drivers in explaining timber loss dynamics, also testing for possible synergistic effects. Local outbreaks shared the same drivers, including increasing summer rainfall deficit and warm temperatures. Large availability...

  15. Virtual disjunct eddy covariance measurements of organic compound fluxes from a subalpine forest using proton transfer reaction mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. G. Karl


    Full Text Available A `virtual' disjunct eddy covariance (vDEC device was tested with field measurements of biogenic VOC fluxes at a subalpine forest site in the Rocky Mountains of the USA. A PTR-MS instrument was used as the VOC sensor. Daily peak emission fluxes of 2-methyl-3-buten-2-ol (MBO, methanol, acetone and acetaldehyde were around 1.5, 1, 0.8 and 0.4 mg m-2 h-1, respectively. High pass filtering due to long sampling lines was investigated in laboratory experiments, and suggested that VOC losses in PTFA lines are generally governed by diffusion laws. Memory effects and surface reactions did not seem to play a dominant role. Model estimates of MBO fluxes compared well with measured fluxes. The results also suggest that latent heat and sensible heat fluxes are reasonably well correlated with VOC fluxes and could be used to predict variations in VOC emissions. The release of MBO, methanol, acetone and acetaldehyde resulted in significant change of tropospheric oxidant levels and a 10--40% increase in ozone levels, as inferred from a photochemical box model. We conclude that vDEC with a PTR-MS instrument is a versatile tool for simultaneous field analysis of multiple VOC fluxes.

  16. Formation of chloroform in soil. A year-round study at a Danish spruce forest site

    DEFF Research Database (Denmark)

    Haselmann, K.F.; Laturnus, F.; Grøn, C.


    Soil air from top soil of a Danish spruce forest was investigated monthly from December 1997 to December 1998 for the occurrence of chloroform, 1,1,1-trichloroethane, tetrachloromethane, trichloroethene and tetrachloroethene. Within the monitoring period, three different patterns of soil air...... concentrations were identified. For chloroform, concentrations peaked in spring and autumn while 1,1,1-trichloroethane and tetrachloromethane peaked during mid winter. Trichloroethene and tetrachloroethene, concentrations remained constant throughout the year. The relative ratios of soil air concentrations...... concentrations were found in the soil in warm and humid periods of the year (spring and autumn) with high microbial activity....

  17. Changes in canopy cover alter surface air and forest floor temperature in a high-elevation red spruce (Picea rubens Sarg.) forest (United States)

    Johnny L. Boggs; Steven G. McNulty


    The objective of this study is to describe winter and summer surface air and forest floor temperature patterns and diurnal fluctuations in high-elevation red spruce (Picea rubens Sarg.) forests with different levels of canopy cover. In 1988, a series of 10- x 10-meter plots (control, low nitrogen [N] addition, and high nitrogen addition) were...

  18. Spruce budworm returns to Northeast (United States)

    Lloyd Irland; William H. McWilliams


    Thinking of the Northern Forest brings to mind spruce/fir (S/F) forests, cool climates, and high elevations: not to mention fishing and canoe trips: however, spruce and fir are also very important to the northern timber economy and rural development. Considering new concerns over the spruce budworm, an update on the status of this critically important forest resource...

  19. Modeling carbon dynamics in two adjacent spruce forests with different soil conditions in Russia

    Directory of Open Access Journals (Sweden)

    J. Kurbatova


    Full Text Available Net ecosystem carbon exchange (NEE was measured with eddy covariance method for two adjacent forests located at the southern boundary of European taiga in Russia in 1999–2004. The two spruce forests shared similar vegetation composition but differed in soil conditions. The wet spruce forest (WSF possessed a thick peat layer (60 cm with a high water table seasonally close to or above the soil surface. The dry spruce forest (DSF had a relatively thin organic layer (5 cm with a deep water table (>60 cm. The measured multi-year average NEE fluxes (2000 and –1440 kg C ha−1yr−1 for WSF and DSF, respectively indicated that WSF was a source while DSF a sink of atmospheric carbon dioxide (CO2 during the experimental years. A process-based model, Forest-DNDC, was employed in the study to interpret the observations. The modeled multi-year average NEE fluxes were 1800 and –2200 kg C ha−1yr−1 for WSF and DSF, respectively, which were comparable with observations. The modeled data also showed high soil heterotrophic respiration rates at WSF that suggested that the water table fluctuation at WSF could have played a key role in determining the negative carbon balance in the wetland ecosystem. A sensitivity test was conducted by running Forest-DNDC with varied water table scenarios for WSF. The results indicated that the NEE fluxes from WSF were highly sensitive to the water table depth. When the water table was high, the WSF ecosystem maintained as a sink of atmospheric CO2; while along with the drop of the water table the length of the flooded period reduced and more organic matter in the soil profile suffered from rapid decomposition that gradually converted the ecosystem into a source of atmospheric CO2. The general effect of water table variation on wetland carbon balance observed from this modeling study could be applicable for a wide range of wetland ecosystems that

  20. Tropospheric ozone fluxes in Norway spruce forest during the transition period from autumn to winter (United States)

    Juran, Stanislav; Fares, Silvano; Zapletal, Miloš; Cudlín, Pavel; Večeřa, Zbyněk; Urban, Otmar


    Norway spruce exhibits seasonal variations in stomatal conductance and photosynthetic activity typical for overwintering plants, with a decline during autumn and a complete recovery during spring. We investigated ozone fluxes during this transient period (November 2016). Fluxes of tropospheric ozone, the major phytotoxic near-ground pollutant causing injuries to plant tissues, were measured at Bily Kriz experimental station in Beskydy Mountains, the Czech Republic. Dry chemiluminescence fast-response ozone sensor coupled with sonic anemometer was used to measure fast fluctuations in ozone concentration and three-dimensional wind speed, respectively. Apart from this eddy covariance technique, within-canopy ozone concentration gradient was simultaneously measured by UV-absorption based slow-response ozone analysers. Ozone fluxes were subsequently modelled by an Inverse Lagrangian Transport Model (ILTM). A comparison of measured and calculated fluxes is thus available. Moreover, stomatal ozone flux was calculated based on Evaporative/Resistive method assuming stomata are the most relevant sink in the spruce forest. The low NOx concentration throughout the year and low concentrations of volatile organic compounds (VOCs) during the transition period led to hypothesize that non-stomatal flux here estimated by difference between total ozone flux and stomatal ozone flux is represented mainly by dry soil deposition and wet deposition during the snow period. We discuss here the ILTM parameterisation with comparison to measured ozone fluxes. Correct estimation of stomatal ozone flux is essential, especially in transition periods, where main scientific emphasis is put rarely. In addition, this research should help to develop metrics for ozone-risk assessment and advance our knowledge in biosphere-atmosphere exchange over Norway spruce forest. Acknowledgement This work was supported by the Ministry of Education, Youth and Sports within the National Programme for Sustainability

  1. Beyond CO2 - Tackling the full greenhouse gas budget of a sub-alpine forest ecosystem (United States)

    Burri, Susanne; Merbold, Lutz; Meier, Philip; Eugster, Werner; Hörtnagl, Lukas; Buchmann, Nina


    In order to tackle the full greenhouse gas (GHG) budgets of forest ecosystems, it is desirable but challenging to quantify the three major GHGs, i.e. CO2, CH4 and N2O simultaneously in-situ. At the long-term forest research site Davos (Candidate Class I Ecosystem Station within the Integrated Carbon Observation System - ICOS), we have recently installed a state-of-the-art measuring system simultaneously to observe the three GHGs on a high temporal resolution and both within and above the forest canopy. Thereby, we combine above-canopy eddy covariance flux measurements and forest floor chamber flux measurements (using five custom-made fully automated chambers). Both systems are connected to a quantum cascade laser absorption spectrometer (QCL, Aerodyne) and measurements are switched between three hours of above-canopy and one hour of forest floor GHG flux measurements. Using this approach, we will be able to study the full GHG budget as well as the dynamics of the individual fluxes on two vertical levels within the forest using a single instrument. The first results presented here will highlight the suitability of this promising tool for quantifying the full GHG budget of forest ecosystems.

  2. The influence of changes in soil moisture in association with geomorphic change on the formation of a subalpine coniferous forest on Mt. Akita-Komagatake, northern Japan (United States)

    Konno, A.


    The coniferous forest (largely composed of Abies mariesii) is presently the typical vegetation of the subalpine zone in Japan. Pollen analysis revealed that few A. mariesii were present during the last glacial period, and the species began to expand to the subalpine zone during the Holocene (Morita, 1992). However, on Mt. Akita-Komagatake in northern Japan, the expected predominance of A. mariesii is not extensively observed, and the predominant vegetation is instead the dwarf bamboo (Sasa kurilensis). It is unknown why the area under coniferous forest is small in this region. Therefore, I examined this issue from the perspectives of (1) distribution of vegetation, (2) geomorphology, (3) soil moisture, and (4) vegetation history. (1) Precise digital elevation model data and photographic interpretation showed that this coniferous forest was densely distributed in a flat segment considered to be formed by a landslide; (2) this landslide is thought to have occurred up to 3,699 ± 26 yr BP because a boring-core specimen from the landslide included the AK-3 tephra layer (2,300-2,800 yr BP: Wachi et al, 1997) and the radiocarbon date of the lowermost humic soil layer was 3,699 ± 26 yr BP; (3) the soil in the forest area had higher volumetric water content than that in the non-forest area; and (4) phytolith analysis revealed that the main species in the study site was initially dwarf bamboo, but coniferous forest replaced it after the Towada-a tephra (1035 cal. BP, Machida and Arai, 1992) layer fell. These results suggest that soil water conditions changed because of the formation of the flat segment by the landslide, and the coniferous forest was consequently established. However, the landslide only indirectly affected the formation of the coniferous forest, because the forest developed over several thousand years after the landslide occurred. In other words, more direct reasons for the establishment of the coniferous forest may involve changes in soil moisture. This

  3. Total and pyrogenic carbon stocks in black spruce forest floors from eastern Canada (United States)

    Soucemarianadin, Laure; Quideau, Sylvie; MacKenzie, M. Derek; Munson, Alison; Boiffin, Juliette; Bernard, Guy; Wasylishen, Roderick


    In boreal forests, pyrogenic carbon (PyC), a by-product of recurrent wildfires, is an important component of the global soil C pool, although precise assessment of boreal PyC stock is scarce. In this study including 14 fire sites spreading over 600 km in the Quebec province, our aim was to better estimate total C stock and PyC stock in forest floors of Eastern Canada boreal forests. We also investigated the environmental conditions controlling the stocks and characterized the composition of the various forest floor layers. We analyzed the forest floor samples that were collected from mesic black spruce sites recently affected by fire (3-5 years) using elemental analysis and solid state 13C nuclear magnetic resonance (NMR) spectroscopy. PyC content was further estimated using a molecular mixing model on the 13C NMR data. Total C stock in forest floors averaged 5.7 ± 2.9 kg C/m2 and PyC stock 0.6 ± 0.3 kg C/m2. Total C stock was under control of the position in the landscape, with a greater accumulation of organic material on northern aspects and lower slope positions. In addition, total stock was significantly higher in spruce-dominated forest floors than in stands where jack pine was dominant. The PyC stock was significantly related to the atomic H/C ratio (R2 = 0.84) of the different organic layers. 13C NMR spectroscopy revealed a large increase in aromatic carbon in the deepest forest floor layer (humified H horizon) at the organic-mineral soil interface. The majority of the PyC stock was located in this horizon and had been formed during past high severity fires rather than during the most recent fire event. Conversely, the superficial "fresh" PyC layer, produced by early-season wildfires in 2005-2007, had NMR spectra fairly similar to unburned forest floors and comparatively low PyC stocks.

  4. 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.


    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......, i.e. an ammonia concentration below which the trees and/or the surface emit ammonia due to an equilibrium with the ammonia inside the needles or on the surface. Emission of ammonia was also observed at relatively high ammonia concentration levels (above 2 mu g NH3-N m(-3)), mainly during one...... 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...

  5. Feedbacks between climate, fire severity, and differential permafrost degradation in Alaskan black spruce forests - implications for carbon cycling (United States)

    Kasischke, E. S.; Kane, E. S.; O'Donnell, J. A.; Christensen, N. L.; Mitchell, S. R.; Turetsky, M. R.; Hayes, D. J.; Hoy, E.; Barrett, K. M.; McGuire, A. D.; Yuan, F.


    Black spruce forests are the dominant forest cover type in the boreal region of Alaska and Canada In the northern portion of its range, permafrost is common to sites occupied by black spruce forest, which in turn, leads topromotes the accumulation of large reservoirs of organic carbon in mineral and organic soils. Another important trait of black spruce forests is the high occurrence of fire which is enhanced by the presence of flammable foliage, surface litter (duff), dead stems, aboreal lichens, and understory vegetation that is highly flammable during the dry conditions found during the summer fire season. In turn, fire plays an important role in carbon cycling in black spruce forests through direct burning of vegetation and organic soils, initiation of secondary succession, and alteration of the ambient environmental conditions, in particular, the permafrost and the soil thermal regimes, including permafrost stability. The spatial and temporal characteristics of permafrost (e.g. ice content and, seasonal deepening thawing of the active layer) not only control fire severity in terms of depth of burning of the active layer, but also the level of permafrost degradation that occurs in the post-fire environment. Fire severity, in combination with soil thermal properties (e.g. temperature, moisture, permafrost state), moisture and temperature conditions controlled by rates of permafrost warming and drying then controls the biological processes (plant succession and growth and heterotrophic respiration), thus regulating post-fire re-accumulation of carbon in biomass. In this paper, we will review research that investigates the interactions between fire and permafrost regimes that influence and how they influence carbon cycling in black spruce forests in interior Alaska.

  6. 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


    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.

  7. Stakeholders' relationships with the USDA Forest Service at the Spruce Knob-Seneca Rocks National Recreation Area, West Virginia (United States)

    Katherine A. Thompson; Chad D. Pierskalla; Steven W. Selin


    The Spruce Knob-Seneca Rocks National Recreation Area (NRA) is developing a collaborative management plan. To develop a public involvement strategy, it is necessary to assess the social conditions in the area. The purpose of this study was to determine the relationship local stakeholders in the NRA have with the USDA Forest Service (USFS) with regard to the...

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

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


    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...

  9. Structure and dynamics in a virgin northern hardwood-spruce-fir forest--the Bowl, New Hampshire (United States)

    Stanley R. Gemborys


    A phytosociological study was conducted in a virgin northern hardwood- spruce-fir forest in the Bowl in the White Mountains of New Hampshire. There is no evidence of fire or human disturbance but hurricane winds were significant in the past. Bray and Curtis ordination was used to develop an XY vegetational mosaic. Differentiating species were Picea rubens and Acer...

  10. Genetic diversity, genetic structure, and mating system of brewer spruce (Pinaceae), a relict of the acto-tertiary forest (United States)

    F. Thomas Ledig; Paul D. Hodgskiss; David R. Johnson


    Brewer spruce (Picea breweriana), a relict of the widespread Arcto-Tertiary forests, is now restricted to a highly fragmented range in the Klamath Region of California and Oregon. Expected heterozygosity for 26 isozyme loci, averaged over 10 populations, was 0.121. More notable than the relatively high level of diversity when compared to other woody...

  11. Vegetation types and climate conditions reflected by the modern phytolith assemblages in the subalpine Dalaoling Forest Reserve, central China (United States)

    Traoré, Djakanibé Désiré; Gu, Yansheng; Liu, Humei; Shemsanga, Ceven; Ge, Jiwen


    This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assemblages, and climatic indices were used to study the relationship between local vegetation and climate conditions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups: long cells, short cells, bulliform cells, hair cells, pteridophyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae (rondel and trapeziform), Panicoideae (bilobate, cross, and polylobate), Chloridoideae (short/square saddle), and Bambusoideae (oblong concave saddle). Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity (Iph), climate (Ic), and tree cover density (D/P), five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn: warm-wet, warm-xeric to warm-mesic, warm-xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance of phytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.

  12. Spruce forests (Ass. Sphango girgensohnii - Piceetum (Br.-Bl. 39 Polak. 62 on excessively moistened peatlands in Latvia

    Directory of Open Access Journals (Sweden)

    Normunds Priedits


    Full Text Available The research carried out on swamp spruce forests on peatland in Latvia gives a detailed notion of the phytosociological structure of Ass. Sphagno girgensohnii - Piceetum (Br. - BI. 39 Polak. 62 in the western part of the East-European Plain at the Baltic Sea. The paper reflects one of the aspects of swamp forest investigation results in Latvia on forest communities, its biodiversity and presevation. Ninety-one sample plots with Picea abies as the dominant in the tree layer or co-dominant with Betula pendula, Betula pubescens or Pinus sylvestris are described according to phytosociological Braun-Blanquet methodology. Floristic features of spruce communities belonging to Caricoso-phragmitosa and Dryopterioso-cnricosa forest site types are analysed. The results are compared with similar investigations carried out in the Baltic Sea region states and neighbouring countries.

  13. Characterizing water, energy and CO2 exchange for a Sky Island subalpine forest in the southwestern USA (United States)

    Brown-Mitic, C. M.; Shuttleworth, J.; Harlow, C.; Bales, R.


    Among the ecosystems present in the semi-arid environment of the Southwestern U.S., Sky Island forest is unique and it has a unique relationship to the sparse surface-water resources available in the region. This ecosystem exists only at the top of mountains because it is only here that, as a long-term average, precipitation input exceeds evapotranspiration to the extent that forest vegetation can survive. Sky Island Forests, therefore, command potentially significant source areas for the water (some originally falling as snow) that ultimately leaves topographically high ground to recharge aquifers in the plains below by mountain-front recharge. They are also very recently recognized as important carbon sinks where very little or no understanding exist of the exchange/cycling dynamics. The Mount Bigelow project provides an empirically based understanding of the hydro- micrometeorological dynamics of a sky island sub-alpine forest in the southwestern U.S. It is the first study to attempt to document, understand, and model the water, energy, and (related) carbon exchanges of the uniquely interesting and, from the water resource standpoint, uniquely important Sky Island forest ecosystem. The fundamental science issues addressed are: the characteristics of the surface-atmosphere exchanges of water, energy and carbon; the storage of moisture and energy in plants and soil; partitioning of winter snow and rain between evapotranspiration/sublimation, deep drainage and the near-surface environmental water resource that sustains the forest. In order to achieve our objective, a network of four below canopy hydro-micrometeorological stations 10 m tall, and one above canopy 30 m tall high resolution eddy correlation tower, were deployed within a predominantly douglas fir/pine second growth forest. Our observations indicate that the surface flux potential (i.e. sensible heat flux (H) potential), defined as the surface-air temperature gradient varies significantly over space as

  14. Comparing modern and presettlement forest dynamics of a subboreal wilderness: Does spruce budworm enhance fire risk? (United States)

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


    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

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

    Directory of Open Access Journals (Sweden)

    Ahmed Laamrani


    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.

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

    Directory of Open Access Journals (Sweden)

    Peter F. Newton


    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.

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

    Directory of Open Access Journals (Sweden)

    Hilszczański Jacek


    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.

  18. Assessing the resilience of Norway spruce forests through a model-based reanalysis of thinning trials. (United States)

    Seidl, Rupert; Vigl, Friedrich; Rössler, Günter; Neumann, Markus; Rammer, Werner


    As a result of a rapidly changing climate the resilience of forests is an increasingly important property for ecosystem management. Recent efforts have improved the theoretical understanding of resilience, yet its operational quantification remains challenging. Furthermore, there is growing awareness that resilience is not only a means to addressing the consequences of climate change but is also affected by it, necessitating a better understanding of the climate sensitivity of resilience. Quantifying current and future resilience is thus an important step towards mainstreaming resilience thinking into ecosystem management. Here, we present a novel approach for quantifying forest resilience from thinning trials, and assess the climate sensitivity of resilience using process-based ecosystem modeling. We reinterpret the wide range of removal intensities and frequencies in thinning trials as an experimental gradient of perturbation, and estimate resilience as the recovery rate after perturbation. Our specific objectives were (i) to determine how resilience varies with stand and site conditions, (ii) to assess the climate sensitivity of resilience across a range of potential future climate scenarios, and (iii) to evaluate the robustness of resilience estimates to different focal indicators and assessment methodologies. We analyzed three long-term thinning trials in Norway spruce (Picea abies (L.) Karst.) forests across an elevation gradient in Austria, evaluating and applying the individual-based process model iLand. The resilience of Norway spruce was highest at the montane site, and decreased at lower elevations. Resilience also decreased with increasing stand age and basal area. The effects of climate change were strongly context-dependent: At the montane site, where precipitation levels were ample even under climate change, warming increased resilience in all scenarios. At lower elevations, however, rising temperatures decreased resilience, particularly at

  19. Declines in low-elevation subalpine tree populations outpace growth in high-elevation populations with warming (United States)

    Conlisk, Erin; Castanha, Cristina; Germino, Matthew J.; Veblen, Thomas T; Smith, Jeremy M.; Kueppers, Lara M.


    Species distribution shifts in response to climate change require that recruitment increase beyond current range boundaries. For trees with long life spans, the importance of climate-sensitive seedling establishment to the pace of range shifts has not been demonstrated quantitatively.Using spatially explicit, stochastic population models combined with data from long-term forest surveys, we explored whether the climate-sensitivity of recruitment observed in climate manipulation experiments was sufficient to alter populations and elevation ranges of two widely distributed, high-elevation North American conifers.Empirically observed, warming-driven declines in recruitment led to rapid modelled population declines at the low-elevation, ‘warm edge’ of subalpine forest and slow emergence of populations beyond the high-elevation, ‘cool edge’. Because population declines in the forest occurred much faster than population emergence in the alpine, we observed range contraction for both species. For Engelmann spruce, this contraction was permanent over the modelled time horizon, even in the presence of increased moisture. For limber pine, lower sensitivity to warming may facilitate persistence at low elevations – especially in the presence of increased moisture – and rapid establishment above tree line, and, ultimately, expansion into the alpine.Synthesis. Assuming 21st century warming and no additional moisture, population dynamics in high-elevation forests led to transient range contractions for limber pine and potentially permanent range contractions for Engelmann spruce. Thus, limitations to seedling recruitment with warming can constrain the pace of subalpine tree range shifts.

  20. The influence of climate change on stomatal ozone flux to a mountain Norway spruce forest. (United States)

    Zapletal, Miloš; Pretel, Jan; Chroust, Petr; Cudlín, Pavel; Edwards-Jonášová, Magda; Urban, Otmar; Pokorný, Radek; Czerný, Radek; Hůnová, Iva


    Daily stomatal ozone flux to a mountain Norway spruce forest stand at the Bily Kriz experimental site in the Beskydy Mts. (Czech Republic) was modelled using a multiplicative model during the 2009 growing season. The multiplicative model was run with meteorological data for the growing season 2009 and ALADIN-CLIMATE/CZ model data for the 2030 growing season. The exceedance of the flux-based critical level of O(3) (Phytotoxic Ozone Dose) might be lower for Norway spruce at the Bily Kriz experimental site in a future climate (around 2030), due to increased stomatal closure induced by climate change, even when taking into account increased tropospheric background O(3) concentration. In contrast, exceedance of the concentration-based critical level (AOT40) of O(3) will increase with the projected increase in background O(3) concentration. Ozone concentration and stomatal flux of ozone significantly decreased NEP under both present and future climatic conditions, especially under high intensities of solar radiation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Negative impacts of high temperatures on growth of black spruce forests intensify with the anticipated climate warming (United States)

    Girardin, M. P.; Hogg, T.; Kurz, W.; Bernier, P. Y.; Guo, X. J.; Cyr, G.


    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 60ºN 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 modelling. We found that soil water availability is a significant driver of black spruce inter-annual variability in productivity across broad areas of the western to eastern Canadian boreal forest. Inter-annual 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 inter-annual 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nikolova, Petia S., E-mail: nikolova@wzw.tum.d [Ecophysiology of Plants, Technische Universitaet Muenchen, Weihenstephan Center of Life and Food Sciences, Am Hochanger 13, 85354 Freising (Germany); Andersen, Christian P. [Western Ecology Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, 200 SW 35th St., Corvallis, OR 97333 (United States); Blaschke, Helmut; Matyssek, Rainer; Haeberle, Karl-Heinz [Ecophysiology of Plants, Technische Universitaet Muenchen, Weihenstephan Center of Life and Food Sciences, Am Hochanger 13, 85354 Freising (Germany)


    The effects of experimentally elevated O{sub 3} on soil respiration rates, standing fine-root biomass, fine-root production and delta{sup 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{sub 3} under beech and spruce, and was related to O{sub 3}-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O{sub 3} on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O{sub 3} regime. delta{sup 13}C signature of newly formed fine-roots was consistent with the differing g{sub s} of beech and spruce, and indicated stomatal limitation by O{sub 3} in beech and by drought in spruce. Our study showed that drought can override the stimulating O{sub 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.

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

    Directory of Open Access Journals (Sweden)

    Sophan Chhin


    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.

  4. Warming-induced upslope advance of subalpine forest is severely limited by geomorphic processes (United States)

    Macias-Fauria, Marc; Johnson, Edward A.


    Forests are expected to expand into alpine areas because of climate warming, causing land-cover change and fragmentation of alpine habitats. However, this expansion will only occur if the present upper treeline is limited by low-growing season temperatures that reduce plant growth. This temperature limitation has not been quantified at a landscape scale. Here, we show that temperature alone cannot realistically explain high-elevation tree cover over a >100-km2 area in the Canadian Rockies and that geologic/geomorphic processes are fundamental to understanding the heterogeneous landscape distribution of trees. Furthermore, upslope tree advance in a warmer scenario will be severely limited by availability of sites with adequate geomorphic/topographic characteristics. Our results imply that landscape-to-regional scale projections of warming-induced, high-elevation forest advance into alpine areas should not be based solely on temperature-sensitive, site-specific upper-treeline studies but also on geomorphic processes that control tree occurrence at long (centuries/millennia) timescales. PMID:23569221

  5. Ground-layer composition affects tree fine root biomass and soil nutrient availability in jack pine and black spruce forests under extreme drainage conditions

    National Research Council Canada - National Science Library

    Pacé, Marine; Fenton, Nicole J; Paré, David; Bergeron, Yves

    ....) – lichen and black spruce (Picea mariana (Mill.) B.S.P.) – moss forests, the relationships between canopy closure, ground-layer composition, tree fine root biomass, and soil nutrients were analyzed and decomposed using path analysis...

  6. Ground layer composition affects tree fine root biomass and soil nutrient availability in jack pine and black spruce forests under extreme drainage conditions

    National Research Council Canada - National Science Library

    Pacé, M; Fenton, N.J; Paré, D; Bergeron, Y


    ....) – lichen and black spruce (Picea mariana (Mill.) B.S.P.) – moss forests, the relationships between canopy closure, ground-layer composition, tree fine root biomass, and soil nutrients were analyzed and decomposed using path analysis...

  7. Native red deer and introduced chamois: foraging habits and competition in a subalpine meadow-spruce forest area

    Czech Academy of Sciences Publication Activity Database

    Homolka, Miloslav; Heroldová, Marta


    Roč. 50, č. 2 (2001), s. 89-98 ISSN 0139-7893 R&D Projects: GA ČR GA206/97/0172; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : Cervus elaphus * Rupicapra rupicapra * foraging strategy Subject RIV: EG - Zoology Impact factor: 0.287, year: 2001

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

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    Petráš Rudolf


    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

  9. Biological and physical influences on the carbon isotope content of CO2 in a subalpine forest snowpack, Niwot Ridge, Colorado (United States)

    D. R. Bowling; W. J. Massman; S. M. Schaeffer; S. P. Burns; R. K. Monson; M. W. Williams


    Considerable research has recently been devoted to understanding biogeochemical processes under winter snow cover, leading to enhanced appreciation of the importance of many winter ecological processes. In this study, a comprehensive investigation of the stable carbon isotope composition (δ 13C) of CO2 within a high-elevation subalpine...

  10. The flux of carbonyl sulfide and carbon disulfide between the atmosphere and a spruce forest

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    X. Xu


    Full Text Available Turbulent fluxes of carbonyl sulfide (COS and carbon disulfide (CS2 were measured over a spruce forest in Central Germany using the relaxed eddy accumulation (REA technique. A REA sampler was developed and validated using simultaneous measurements of CO2 fluxes by REA and by eddy correlation. REA measurements were conducted during six campaigns covering spring, summer, and fall between 1997 and 1999. Both uptake and emission of COS and CS2 by the forest were observed, with deposition occurring mainly during the sunlit period and emission mainly during the dark period. On the average, however, the forest acts as a sink for both gases. The average fluxes for COS and CS2 are  -93 ± 11.7 pmol m-2 s-1 and  -18 ± 7.6 pmol m-2 s-1, respectively. The fluxes of both gases appear to be correlated to photosynthetically active radiation and to the CO2 and chem{H_2O} fluxes, supporting the idea that the air-vegetation exchange of both gases is controlled by stomata. An uptake ratio COS/CO2 of 10 ± 1.7 pmol m mol-1 has been derived from the regression line for the correlation between the COS and CO2 fluxes. This uptake ratio, if representative for the global terrestrial net primary production, would correspond to a sink of 2.3 ± 0.5 Tg COS yr-1.

  11. Mercury in forest mushrooms and topsoil from the Yunnan highlands and the subalpine region of the Minya Konka summit in the Eastern Tibetan Plateau. (United States)

    Falandysz, Jerzy; Saba, Martyna; Liu, Hong-Gao; Li, Tao; Wang, Ji-Peng; Wiejak, Anna; Zhang, Ji; Wang, Yuan-Zhong; Zhang, Dan


    This study aimed to investigate and discuss the occurrence and accumulation of mercury in the fruiting bodies of wild-growing fungi (Macromycetes) collected from montane forests in two regions of southwestern China with differences in soil geochemistry, climate and geographical conditions. Fungal mycelia in soils of the subalpine region of the Minya Konka (Gongga Mountain) in Sichuan and in the highlands of Yunnan efficiently accumulated mercury in fruiting bodies (mushrooms). The examined sites in Yunnan with highly mineralized red and yellow soils showed Hg contents ranging from 0.066 to 0.28 mg kg -1 dry biomass (db) which is roughly similar to the results obtained for samples collected from sites with dark soils relatively rich in organic matter from a remote, the subalpine region of Minya Konka. Due to the remoteness of the subalpine section of Minya Konka, as well as its elevation and climate, airborne mercury from long-range transport could be deposited preferentially on the topsoil and the Hg levels determined in soil samples taken beneath the fruiting bodies were up to 0.48 mg kg -1 dry matter. In Yunnan, with polymetallic soils (Circum-Pacific Mercuriferous Belt), Amanita mushrooms showed mercury in caps of fruiting bodies of up to 7.3 mg kg -1 dry biomass. Geogenic Hg from the mercuriferous belt seems to be the overriding source of mercury accumulated in mushrooms foraged in the regions of Yunnan, while long-range atmospheric transport and subsequent deposition are the mercury sources for specimens foraged in the region of Minya Konka.

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

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    Renčo M.


    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.

  13. Responses of Sap Flow of Deciduous and Conifer Trees to Soil Drying in a Subalpine Forest

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    Chunhua Yan


    Full Text Available Co-occurring species may adopt different water-use strategies to adapt to limited soil water. In Jiuzhaigou Valley, a continuous decline in soil water after an initial recharge from the thawing of snow and frozen soil in early spring was observed, but its effects on the sap flow dynamics of co-occurring species are not well understood. To clarify the species-specific water-use strategy, variations in sap flow and environmental conditions were investigated for two co-occurring species (Betula albosinensis Burk. and Pinus tabuliaeformis Carr. in a mixed forest during a transition from the wet to dry period in 2014. Sap flow was measured using Granier-type thermal dissipation probes, and the soil-water content was measured using time-domain reflectometry probes for a successive period. Our study showed that B. albosinensis maintained relatively high transpiration until late into the season regardless of soil moisture, while the transpiration of P. tabuliformis showed a continuous decrease in response to seasonal soil drying. Sap flow for both species exhibited a marked hysteresis in response to meteorological factors and it was conditioned by the soil-water status, especially in the afternoon. We found that P. tabuliformis was sensitive to soil-water conditions, while for B. albosinensis, the sap flow was not very sensitive to changes in soil-water conditions. These results indicate that B. albosinensis could manage the water consumption conservatively under both dry and wet conditions. These results may have implications for evaluating the species-specific water-use strategy and carrying out proper reforestation practices.

  14. 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. (United States)

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


    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% would decrease the amount of

  15. Mercury bioaccumulation in fishes from subalpine lakes of the Wallowa-Whitman National Forest, northeastern Oregon and western Idaho (United States)

    Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick


    Mercury (Hg) is a globally distributed pollutant that poses considerable risks to human and wildlife health. Over the past 150 years since the advent of the industrial revolution, approximately 80 percent of global emissions have come from anthropogenic sources, largely fossil fuel combustion. As a result, atmospheric deposition of Hg has increased by up to 4-fold above pre-industrial times. Because of their isolation, remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited Hg through freshwater food webs, as well as for evaluating the relative importance of Hg loading versus landscape influences on Hg bioaccumulation. The increase in Hg deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in Hg emissions may propagate to changes in Hg bioaccumulation and ecological risk. In this study, we evaluated Hg concentrations in fishes of high-elevation, sub-alpine lakes in the Wallowa-Whitman National Forest in northeastern Oregon and western Idaho. Our goals were to (1) assess the magnitude of Hg contamination in small-catchment lakes to evaluate the risk of atmospheric Hg to human and wildlife health, (2) quantify the spatial variability in fish Hg concentrations, and (3) determine the ecological, limnological, and landscape factors that are best correlated with fish total mercury (THg) concentrations in these systems. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. Importantly, our top statistical model explained 87 percent of the variability in fish THg concentrations among lakes with four key landscape and limnological variables— catchment conifer density (basal area of conifers within a lake’s catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. The basal area of conifers

  16. [Contribution of soil fauna to the mass loss of Betula albosinensis leaf litter at early decomposition stage of subalpine forest litter in western Sichuan]. (United States)

    Xia, Lei; Wu, Fu-Zhong; Yang, Wan-Qin; Tan, Bo


    In order to quantify the contribution of soil fauna to the decomposition of birch (Betula albosinensis) leaf litter in subalpine forests in western Sichuan of Southwest China during freeze-thaw season, a field experiment with different mesh sizes (0.02, 0.125, 1 and 3 mm) of litterbags was conducted in a representative birch-fir (Abies faxoniana) forest to investigate the mass loss rate of the birch leaf litter from 26 October, 2010 to 18 April, 2011, and the contributions of micro-, meso- and macro-fauna to the decomposition of the leaf litter. Over the freeze-thaw season, 11.8%, 13.2%, 15.4% and 19.5% of the mass loss were detected in the litterbags with 0.02, 0. 125, 1 and 3 mm mesh sizes, respectively. The total contribution of soil fauna to the litter decomposition accounted for 39.5% of the mass loss, and the taxa and individual relative density of the soil fauna in the litterbags had the similar variation trend with that of the mass loss rate. The contribution rate of soil fauna to the leaf litter mass loss showed the order of micro- fauna, with the highest contribution of micro-fauna (7.9%), meso-fauna (11.9%), and macro-fauna (22.7%) at the onset of freezing stage, deeply frozen stage, and thawing stage, respectively. The results demonstrated that soil fauna played an important role in the litter decomposition in subalpine forests of western Sichuan during freeze-thaw season.

  17. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests (United States)

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


    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.

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

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    Chersich S


    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.

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

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    Stith T.Gower


    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

  20. Effects of elevated CO₂ and temperature on photosynthesis and leaf traits of an understory dwarf bamboo in subalpine forest zone, China. (United States)

    Li, Yongping; Zhang, Yuanbin; Zhang, Xiaolu; Korpelainen, Helena; Berninger, Frank; Li, Chunyang


    The dwarf bamboo (Fargesia rufa Yi), growing understory in subalpine dark coniferous forest, is one of the main foods for giant panda, and it influences the regeneration of subalpine coniferous forests in southwestern China. To investigate the effects of elevated CO₂, temperature and their combination, the dwarf bamboo plantlets were exposed to two CO₂ regimes (ambient and double ambient CO₂ concentration) and two temperatures (ambient and +2.2°C) in growth chambers. Gas exchange, leaf traits and carbohydrates concentration were measured after the 150-day experiment. Elevated CO₂ significantly increased the net photosynthetic rate (Anet ), intrinsic water-use efficiency (WUEi ) and carbon isotope composition (δ¹³C) and decreased stomatal conductance (g(s)) and total chlorophyll concentration based on mass (Chl(m)) and area (Chl(a)). On the other hand, elevated CO₂ decreased specific leaf area (SLA), which was increased by elevated temperature. Elevated CO₂ also increased foliar carbon concentration based on mass (C(m)) and area (C(a)), nitrogen concentration based on area (N(a)), carbohydrates concentration (i.e. sucrose, sugar, starch and non-structural carbohydrates) and the slope of the A(net)-N(a) relationship. However, elevated temperature decreased C(m), C(a) and N(a). The combination of elevated CO₂ and temperature hardly affected SLA, C(m), C(a), N(m), N(a), Chl(m) and Chl(a). Variables Anet and Na had positive linear relationships in all treatments. Our results showed that photosynthetic acclimation did not occur in dwarf bamboo at elevated CO₂ and it could adjust physiology and morphology to enable the capture of more light, to increase WUE and improve nutritional conditions. Copyright © Physiologia Plantarum 2012.

  1. Steam pretreatment of spruce forest residues: optimal conditions for biogas production and enzymatic hydrolysis. (United States)

    Janzon, Ron; Schütt, Fokko; Oldenburg, Saskia; Fischer, Elmar; Körner, Ina; Saake, Bodo


    Steam refining of non-debarked spruce forest residues was investigated as pretreatment for enzymatic hydrolysis as well as for biogas production. Pretreatment conditions were varied in the range of 190-220 °C, 5-10 min and 0-3.7% SO₂ according to a statistical design. For both applications highest product yields were predicted at 220 °C and 2.4% SO₂, whereas the reaction time had only a minor influence. The conformity of the model results allows the conclusion that enzymatic hydrolysis is a suitable test method to evaluate the degradability of lignocellulosic biomass in the biogas process. In control experiments under optimal conditions the results of the model were verified. The yield of total monomeric carbohydrates after enzymatic hydrolysis was equivalent to 55% of all theoretically available polysaccharides. The corresponding biogas yield from the pretreated wood amounted to 304 mL/gODM. Furthermore, furans produced under optimal process conditions showed no inhibitory effect on biogas production. It can be concluded that steam refining opens the structure of wood, thus improving the enzymatic hydrolysis of the polysaccharides to fermentable monomeric sugars and subsequently enabling a higher and faster production of biogas. Anaerobic fermentation of pretreated wood is a serious alternative to alcoholic fermentation especially when low quality wood grades and residues are used. Anaerobic digestion should be further investigated in order to diversify the biorefinery options for lignocellulosic materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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    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.

  3. Threshold Responses of Aspen and Spruce Growth to Temperature May Presage a Regime Shift in the Boreal Forest (United States)

    Lloyd, A. H.; Duffy, P.; Mann, D. H.; Leonawicz, M.; Blumstein, M.; Pendall, E.


    Warming in boreal regions may eventually lead to the demise of evergreen coniferous forest and its replacement by either an open parkland of more drought-tolerant deciduous species like aspen, or by treeless steppe vegetation. We examined the possibility of warming-induced regime shifts in the boreal forest by quantifying the response of tree growth to climate on steep, south-facing bluffs in interior Alaska. These sites are the ecotone between forest and subarctic steppe vegetation, and represent the warmest, driest sites occupied by trees in the boreal forests of interior Alaska. We collected tree cores from aspen (Populus tremula) and white spruce (Picea glauca) at south-facing bluffs in interior Alaska (n=9 for white spruce, n=5 for aspen). Crossdated chronologies of detrended, standardized ring-widths were produced for each species at each site, and growth response to climate was quantified using generalized boosting models (spruce) and random forest regression (aspen). These analyses yielded three important insights into the potential for regime shifts in the warmer areas of the boreal forest. First, our results highlighted the surprising similarity in growth response of aspen and spruce. We expected to find that aspen would be more tolerant of warm, dry conditions than white spruce. In contrast, we found that the two species had broadly similar responses to climate, preferring cooler and wetter conditions. This finding suggests that a continued trend towards warmer and drier conditions is more likely to lead rapidly to the replacement of forest vegetation by steppe grassland, rather than the replacement of white spruce by aspen. Second, we identified strongly nonlinear responses to climate in both species; the use of analytical methods capable of detecting and describing nonlinear relationships between growth and climate thus proved to be critical. For both species, steep thresholds in growth response to temperature occurred, particularly in spring. Small

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

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    Gilles Joanisse


    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.

  5. Effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate (United States)

    Jafarov, Elchin E.; Romanovsky, Vladimir E.; Genet, Helene; McGuire, Anthony David; Marchenko, Sergey S.


    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.

  6. NACP Soil Organic Matter of Burned Boreal Black Spruce Forests, Alaska, 2009-2011 (United States)

    National Aeronautics and Space Administration — This data set provides organic soil layer characteristics, estimated carbon content, and soil depth measurements made at four black spruce stands in interior Alaska...

  7. Exploring the landscape evolution of the subalpine meadow-forest system driven by the geomorphic work performed by the Northern Pocket Gopher (United States)

    Winchell, E. W.; Anderson, R. S.; Lombardi, E. M.; Doak, D. F.


    In the subalpine zone of the Colorado Front Range, field observations suggest that the Northern Pocket Gopher acts as a significant geomorphic agent within meadows, but not within forests. Field surveys during 2014 and 2015 demonstrate that the temporal and spatial digging patterns of gopher-excavated mounds and infilled tunnels are neither steady nor uniform. These include 1) gophers spend the winter near the forest-meadow (FM) edge and the remainder of the year within the meadow, and 2) surface mound generation greatly accelerates in late summer. Hourly subsurface temperatures across the FM pair, and daily digital snow depths at the FM boundary suggest that gophers spend the winter beneath thick snow cover where ground temperatures are warmest. LiDAR-based topography demonstrates that slopes are uniform across the FM pairs, diverging from that expected by extrapolation of the observed pattern of non-uniform geomorphic activity. The topography therefore suggests that the FM boundaries are not stationary. We hypothesize that the landscape is more uniformly impacted by gopher activity in the long term, which requires that 1) FM boundaries migrate significantly and/or 2) meadows are born in different places following forest death via fire followed by rapid gopher habitation. The vertical geomorphic signature of gopher activity is more distinct. Preliminary probing of meadows reveals a 20 cm thick biomantle with a high concentration of stones at ~20 cm depth. The annual surface areas of mounds and infilled tunnels suggest that the entire meadow can be exposed to excavated tillings on century timescales. Further, annual mound volumes suggest that the biomantle is turned over also on century timescales. We will report results of stone line surveys and 137Cs concentration profiles within the forest and meadow that will test the long-term stability of meadows and the timescale over which vertical churning mixes the near-surface material within this landscape.

  8. Updating beliefs and combining evidence in adaptive forest management under climate change: a case study of Norway spruce (Picea abies L. Karst) in the Black Forest, Germany. (United States)

    Yousefpour, Rasoul; Temperli, Christian; Bugmann, Harald; Elkin, Che; Hanewinkel, Marc; Meilby, Henrik; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark


    We study climate uncertainty and how managers' beliefs about climate change develop and influence their decisions. We develop an approach for updating knowledge and beliefs based on the observation of forest and climate variables and illustrate its application for the adaptive management of an even-aged Norway spruce (Picea abies L. Karst) forest in the Black Forest, Germany. We simulated forest development under a range of climate change scenarios and forest management alternatives. Our analysis used Bayesian updating and Dempster's rule of combination to simulate how observations of climate and forest variables may influence a decision maker's beliefs about climate development and thereby management decisions. While forest managers may be inclined to rely on observed forest variables to infer climate change and impacts, we found that observation of climate state, e.g. temperature or precipitation is superior for updating beliefs and supporting decision-making. However, with little conflict among information sources, the strongest evidence would be offered by a combination of at least two informative variables, e.g., temperature and precipitation. The success of adaptive forest management depends on when managers switch to forward-looking management schemes. Thus, robust climate adaptation policies may depend crucially on a better understanding of what factors influence managers' belief in climate change. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Process coupling and control over the response of net ecosystem CO2 exchange to climate variability and insect disturbance in subalpine forests of the Western US (United States)

    Monson, R. K.; Moore, D. J.; Trahan, N. A.; Scott-Denton, L.; Burns, S. P.; Hu, J.; Bowling, D. R.


    Following ten years of studies in subalpine forest ecosystems of the Western US, we have concluded that the tight coupling between gross primary productivity (GPP) and the autotrophic component of soil respiration (Ra) drives responses of net ecosystem CO2 exchange (NEE) to climate variability and insect disturbance. This insight has been gained through long-term eddy flux observations, manipulative plot experiments, analyses of dynamics in the stable isotope compositions of CO2 and H2O, and chamber gas-exchange measurements. Using past observations from these studies, we deployed model-data assimilation techniques and forecast weather/climate modeling to estimate how the coupling between GPP and Ra is likely to affect future (Year 2100) dynamics in NEE. The amount of winter snow and its melting dynamics in the spring represents the dominant control over interannual variation in GPP. Using the SIPNET ecosystem process model, combined with knowledge about the stable isotope content of different water sources, we estimated that approximately 75% of growing season GPP is coupled to the use of snowmelt water, whereas approximately 25% is coupled to summer rain. The tight coupling between GPP and winter snow pack drives a similar tight coupling between soil respiration (Rs) and winter snow pack. Manipulation of snow pack on forest plots has shown that Rs increases with increased snow pack, and this effect disappears when trees are girdled, which stops the transfer of GPP to roots and the soil rhizosphere. Higher-than-normal winter snowpacks cause the carbon isotope ratios of soil-respired CO2 to be depleted in 13C, reflecting a signal of lower photosynthetic water-use efficiency in the GPP that is transferred to the soil rhizosphere. Large-scale forest disturbance due to catastrophic tree mortality from mountain pine beetle attack causes an initial (2-3 year) reduction in Rs, which is attributable to the loss of GPP and its effect on Ra. This near-term reduction in Rs

  10. The role of soil drainage class in carbon dioxide exchange and decomposition in boreal black spruce (Picea mariana) forest stands (United States)

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


    Black spruce (Picea mariana (Mill.) B.S.P.) forest stands range from well drained to poorly drained, typically contain large amounts of soil organic carbon (SOC), and are often underlain by permafrost. To better understand the role of soil drainage class in carbon dioxide (CO2) exchange and decomposition, we measured soil respiration and net CO2 fluxes, litter decomposition and litterfall rates, and SOC stocks above permafrost in three Alaska black spruce forest stands characterized as well drained (WD), moderately drained (MD), and poorly drained (PD). Soil respiration and net CO2 fluxes were not significantly different among sites, although the relation between soil respiration rate and temperature varied with site (Qw: WD > MD > PD). Annual estimated soil respiration, litter decomposition, and groundcover photosynthesis were greatest at PD. These results suggest that soil temperature and moisture conditions in shallow organic horizon soils at PD were more favorable for decomposition compared with the better drained sites. SOC stocks, however, increase from WD to MD to PD such that surface decomposition and C storage are diametric. Greater groundcover vegetation productivity, protection of deep SOC by permafrost and anoxic conditions, and differences in fire return interval and (or) severity at PD counteract the relatively high near-surface decomposition rates, resulting in high net C accumulation.

  11. Environmental equity and the conservation of unique ecosystems: an analysis of the distribution of benefits for protecting Southern Appalachian spruce-fir forests (United States)

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


    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...

  12. Below-ground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L. / Picea abies [L.] Karst) (United States)

    The effects of experimentally elevated O3 on soil respiration rates, standing fine-root biomass, fine-root production and δ13C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with cont...

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

    Lisa M. Lumley; Felix A.H. Sperling


    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....

  14. The effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate (United States)

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


    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)...

  15. 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


    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

  16. (13)C NMR spectroscopy characterization of particle-size fractionated soil organic carbon in subalpine forest and grassland ecosystems. (United States)

    Shiau, Yo-Jin; Chen, Jenn-Shing; Chung, Tay-Lung; Tian, Guanglong; Chiu, Chih-Yu


    Soil organic carbon (SOC) and carbon (C) functional groups in different particle-size fractions are important indicators of microbial activity and soil decomposition stages under wildfire disturbances. This research investigated a natural Tsuga forest and a nearby fire-induced grassland along a sampling transect in Central Taiwan with the aim to better understand the effect of forest wildfires on the change of SOC in different soil particle scales. Soil samples were separated into six particle sizes and SOC was characterized by solid-state (13)C nuclear magnetic resonance spectroscopy in each fraction. The SOC content was higher in forest than grassland soil in the particle-size fraction samples. The O-alkyl-C content (carbohydrate-derived structures) was higher in the grassland than the forest soils, but the alkyl-C content (recalcitrant substances) was higher in forest than grassland soils, for a higher humification degree (alkyl-C/O-alkyl-C ratio) in forest soils for all the soil particle-size fractions. High humification degree was found in forest soils. The similar aromaticity between forest and grassland soils might be attributed to the fire-induced aromatic-C content in the grassland that offsets the original difference between the forest and grassland. High alkyl-C content and humification degree and low C/N ratios in the fine particle-size fractions implied that undecomposed recalcitrant substances tended to accumulate in the fine fractions of soils.

  17. The effects of forty years of spruce cultivation in a zone of beech forest on mt. Maljen (Serbia

    Directory of Open Access Journals (Sweden)

    Pavlović P.


    Full Text Available This study investigates the effects of the forty-year cultivation of Picea abies on the floristic composition, physical and chemical soil characteristics, and the intensity of organic matter decomposition in a zone of mountainous beech forest (mt. Maljen, northwestern Serbia. The long-term cultivation of conifers in a deciduous habitat has caused a reduction in biodiversity, as well as changes in the soil which were most pronounced in the top soil layer. There were found to be lower soil moisture levels (p<0.05, lower active (p<0.01 and substitutional acidity (p<0.001, depletion of the adsorption complex in base cations (p<0.001, and lower levels of n, P and K (p<0.001 in the spruce stand in relation to the beech stand (control. The higher C/n ratio of spruce litter (p<0.001 caused its lower decomposition rate in comparison to beech litter (p<0.01. All these changes have led to degradation and a reduction in this ecosystem’s productivity. [Acknowledgments. This work was supported by the ministry of education and Science of Serbia, grant no 173018

  18. Relative role of understory and overstory in carbon and nitrogen cycling in a southern Appalachian spruce-fir forest

    Energy Technology Data Exchange (ETDEWEB)

    Moore, P.T.; Van Miegroet, H. [Utah State Univ., Logan, UT (United States). Dept. of Wildland Resources and the Ecology Center; Nicholas, N.S. [Yosemite National Park, El Portal, CA (United States). Resources Management and Science Div.


    This study examined pools and fluxes of biomass, carbon (C) and nitrogen (N) in the overstory and understory of a southern Appalachian red spruce and Fraser fir forest after adelgid-induced fir mortality and spruce windthrow. Standing biomass and fluxes of all growth forms from periodic stand inventories, vegetation surveys, and allometric equations were estimated. Plant- and tissue-specific C and N concentrations were used to calculate total C and N pools and fluxes. Results of the study showed that total aboveground biomass re-attained values observed before the disturbances. Overstory biomass production and N uptake exceeded values observed in earlier reports. The woody overstory accounted for 3 per cent of all aboveground biomass as well as 10 per cent of annual productivity, and 19 per cent of total N uptake. It was concluded that the N-rich understory vegetation plays a significant role in N cycling, and contributed to overall productivity of the system. Further research is needed to examine the relationships between the over- and understories in order to investigate future changes in nutrient cycling. 60 refs., 2 tabs., 4 figs.

  19. Calcium status of the forest floor in red spruce forests of the northeastern U.S. - past, present and future (United States)

    Mark B. David; Gregory B. Lawrence; Walter C. Shortle; Scott W. Bailey


    Dieback and growth decline of red spruce (Picea rubens) in the eastern U.S. coincides with the period of acidic deposition, and has led to much speculation as to whether this decline is caused by decreased root-available Ca in the soil.

  20. Evaluating the utility and seasonality of NDVI values for assessing post-disturbance recovery in a subalpine forest. (United States)

    Buma, Brian


    Forest disturbances around the world have the potential to alter forest type and cover, with impacts on diversity, carbon storage, and landscape composition. These disturbances, especially fire, are common and often large, making ground investigation of forest recovery difficult. Remote sensing offers a means to monitor forest recovery in real time, over the entire landscape. Typically, recovery monitoring via remote sensing consists of measuring vegetation indices (e.g., NDVI) or index-derived metrics, with the assumption that recovery in NDVI (for example) is a meaningful measure of ecosystem recovery. This study tests that assumption using MODIS 16-day imagery from 2000 to 2010 in the area of the Colorado's Routt National Forest Hinman burn (2002) and seedling density counts taken in the same area. Results indicate that NDVI is rarely correlated with forest recovery, and is dominated by annual and perennial forb cover, although topography complicates analysis. Utility of NDVI as a means to delineate areas of recovery or non-recovery are in doubt, as bootstrapped analysis indicates distinguishing power only slightly better than random. NDVI in revegetation analyses should carefully consider the ecology and seasonal patterns of the system in question.

  1. Effect of a small clear-cut on soil surface temperature patterns of a spruce forest ecosystem (United States)

    Radler, K.; Olchev, A.; Panferov, O.; Fellert, D.; Gravenhorst, G.


    Rational forest management demands complex study to quantify effects of clear-cutting and windthrows on forest microclimate and soil hydrology. Within the framework of this study microclimate of a small clear-cut (about 2.6 ha) in a spruce forest was investigated using results of continuous microclimatological measurements. Selected study area is located in central part of Germany about 60 km northwest of Goettingen in the Solling highland at 51°46'N and 09°27'E, and about 300m above see level. Most attention in the second phase of the study was focused on analysis of spatial and temporal patterns of soil surface temperature, which strongly influences the growth and development of most plant species as well as the activity and survival of all invertebrates living on and near the ground surface in forest ecosystems. Although surface temperature is ecologically a most relevant parameter, there are very scarce data available describing the soil surface temperature profile between forest and such openings. Soil surface temperature was continuously measured by digital infrared pyrometers (type IN510, Newport Electronics) along a transect from the clear-cut centre to the forest interior perpendicularly to the forest tree line of a south-east facing forest edge during vegetation period 2007. Sensors were installed on a tripod 1m above ground. Data were recorded by mobile meteorological stations providing also continuous measurements of air and soil temperature, solar radiation, air humidity, wind speed and direction with 5 minute temporal resolution. Results of the field measurements show that the surface temperature varies tremendously within a stripe of ±25m around the tree line. The seasonally averaged daily course of the surface temperature along the transect revealed a maximum of 32°C, which was observed exactly at the tree line shortly before noon. It was by 13°C higher than surface temperature measured 25m away within the forest and also higher than at clear

  2. Legacy of Pre-Disturbance Spatial Pattern Determines Early Structural Diversity following Severe Disturbance in Montane Spruce Forests.

    Directory of Open Access Journals (Sweden)

    Radek Bače

    Full Text Available Severe canopy-removing disturbances are native to many temperate forests and radically alter stand structure, but biotic legacies (surviving elements or patterns can lend continuity to ecosystem function after such events. Poorly understood is the degree to which the structural complexity of an old-growth forest carries over to the next stand. We asked how pre-disturbance spatial pattern acts as a legacy to influence post-disturbance stand structure, and how this legacy influences the structural diversity within the early-seral stand.Two stem-mapped one-hectare forest plots in the Czech Republic experienced a severe bark beetle outbreak, thus providing before-and-after data on spatial patterns in live and dead trees, crown projections, down logs, and herb cover.Post-disturbance stands were dominated by an advanced regeneration layer present before the disturbance. Both major species, Norway spruce (Picea abies and rowan (Sorbus aucuparia, were strongly self-aggregated and also clustered to former canopy trees, pre-disturbance snags, stumps and logs, suggesting positive overstory to understory neighbourhood effects. Thus, although the disturbance dramatically reduced the stand's height profile with ~100% mortality of the canopy layer, the spatial structure of post-disturbance stands still closely reflected the pre-disturbance structure. The former upper tree layer influenced advanced regeneration through microsite and light limitation. Under formerly dense canopies, regeneration density was high but relatively homogeneous in height; while in former small gaps with greater herb cover, regeneration density was lower but with greater heterogeneity in heights.These findings suggest that pre-disturbance spatial patterns of forests can persist through severe canopy-removing disturbance, and determine the spatial structure of the succeeding stand. Such patterns constitute a subtle but key legacy effect, promoting structural complexity in early

  3. Comparisons of photosynthesis-related traits of 27 abundant or subordinate bryophyte species in a subalpine old-growth fir forest. (United States)

    Wang, Zhe; Bader, Maaike Y; Liu, Xin; Zhu, Zhangming; Bao, Weikai


    Bryophyte communities can exhibit similar structural and taxonomic diversity as vascular plant communities, just at a smaller scale. Whether the physiological diversity can be similarly diverse, and whether it can explain local abundance patterns is unknown, due to a lack of community-wide studies of physiological traits. This study re-analyzed data on photosynthesis-related traits (including the nitrogen, phosphorus and chlorophyll concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies) of 27 bryophyte species in a subalpine old-growth fir forest on the eastern Tibetan Plateau. We explored differences between taxonomic groups and hypothesized that the most abundant bryophyte species had physiological advantages relative to other subdominant species. Principal component analysis (PCA) was used to summarize the differences among species and trait values of the most abundant and other co-occurring subdominant species. Species from the Polytrichaceae were separated out on both PCA axes, indicating their high chlorophyll concentrations and photosynthetic capacities (axis 1) and relatively high-light requirements (axis 2). Mniaceae species also had relatively high photosynthetic capacities, but their light saturation points were low. In contrast, Racomitrium joseph-hookeri and Lepidozia reptans , two species with a high shoot mass per area, had high-light requirements and low nutrient and chlorophyll concentrations and photosynthetic capacities. The nutrient concentrations, photosynthetic capacities, and photosynthetic nutrient use efficiencies of the most abundant bryophyte species did not differ from co-occurring subdominant species. Our research confirms the links between the photosynthesis-related traits and adaptation strategies of bryophytes. However, species relative abundance was not related to these traits.

  4. Variation in carbohydrate source-sink relations of forest and treeline white spruce in southern, interior and northern Alaska. (United States)

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


    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.

  5. Streamwater Chemistry and Nutrient Export During Five Years of Bark Beetle Infestation of Subalpine Watersheds at the Fraser Experimental Forest (United States)

    Rhoades, C.; Elder, K.; Hubbard, R.; Porth, L.


    Forested watersheds of western North America are currently undergoing rapid and extensive canopy mortality caused by a variety of insect species. The mountain pine bark beetle (Dendroctonus ponderosae) began to attack lodgepole pine (Pinus contorta) at the USFS Fraser Experimental Forest in central Colorado in 2002. By 2007, bark beetles had killed 78% of the overstory pine in Fraser research watersheds on average. The hydrologic, climatic, biogeochemical and vegetation records at the Fraser Experimental Forest provide a unique opportunity to quantify the impacts of this widespread, but poorly understood forest disturbance relative to a multi-decade pre-disturbance period. Here we compare seasonal streamwater chemistry and annual nutrient export for the five years since the bark beetle outbreak began with the pre- attack record. Patterns in post-outbreak streamwater biogeochemistry are compared to changes is species composition and proportional loss of overstory basal area for four basins. The influence of the outbreak will depend upon an aggregate of short (i.e. halted overstory water and nutrient use) and longer-term (i.e. altered canopy interception, windthrow, and understory growth) processes, so the hydrologic and biogeochemical implications of current beetle activity will not be fully realized for decades.

  6. Variation in Trembling Aspen and White Spruce Wood Quality Grown in Mixed and Single Species Stands in the Boreal Mixedwood Forest

    Directory of Open Access Journals (Sweden)

    Francis De Araujo


    Full Text Available The Canadian boreal forest is largely represented by mixed wood forests of white spruce (Picea glauca (Moench Voss and trembling aspen (Populus tremuloides Michx. In this study, a total of 300 trees originating from three sites composed of trembling aspen and white spruce with varying compositions were investigated for wood quality traits: one site was composed mainly of aspen, one mainly of spruce and a third was a mixed site. Four wood quality traits were examined: wood density, microfibril angle (MFA, fibre characteristics, and cell wall chemistry. Social classes were also determined for each site in an attempt to provide a more in-depth comparison. Wood density showed little variation among sites for both species, with only significant differences occurring between social classes. The aspen site showed statistically lower MFAs than the aspen from the mixed site, however, no differences were observed when comparing spruce. Fibre characteristics were higher in the pure species sites for both species. There were no differences in carbohydrate contents across sites, while lignin content varied. Overall, the use of social classes did not refine the characterization of sites.

  7. Ecosystem Disturbances in Central European Spruce Forests: a Multi-proxy Integration of Dendroecology and Sedimentary Records (United States)

    Clear, J.; Chiverrell, R. C.; Kunes, P.; Boyle, J.; Kuosmanen, N.; Carter, V.


    The montane Norway spruce (Picea abies) dominated forests of Central Europe are a niche environment; situated outside their natural boreal distribution they are vulnerable to both short term disturbances (e.g. floods, avalanches, fire, windstorm and pathogens) and longer-term environmental change (e.g. climate induced stress, snow regimes). Holocene sediment records from lakes in the High Tatra (Slovakia) and Bohemian (Czech) Mountains show repeated disturbances of the pristine Picea abies-dominated forests as sharp well defined minerogenic in-wash horizons that punctuate the accumulation of organic gyttja. These event horizons span a process continuum from lakes with restricted catchments and limited inflow (e.g. Prazilske Lake, Czech) to more catchment-process dominated lakes with large catchments (e.g. Popradske Lake, Slovakia). The events include complex responses to a global climatic downturn at 8.2ka, other cooler episodes 3.5, 1.6 and 0.5 ka, and to recent discrete wind-storms and pathogen outbreaks. We develop a typology for disturbance events using sediment geochemistry, particle size, mineral magnetism, charcoal and palaeoecology to assess likely drivers of disturbance. For the recent past integrating data from dendroecology and sediments is used to calibrate our longer-term perspective on forest dynamics. Tree-ring series from plots or forest stands are used alongside lake and forest hollow sediments to explore the local, regional and biogeographical scale of forest disturbances. Dendroecological data showing tree-ring gap recruitment and post-suppression growth release highlight frequent disturbance events focused on tree or forest stand spatial scales, but are patchy in terms of their reoccurrence. However they highlight levels of disturbance in the late 19th Century and parallel lake and forest hollow sediments record variable pollen influx (beetle host / non-host ratios) and stratigraphies that include mineral in-wash events. The identified recent

  8. 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.


    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......(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...

  9. Modeling effects of climate change on spruce-fir forest ecosystems: Changes in the montane ecotone between boreal and temperate forests in the Green Mountains, U.S.A, from forest edge detection in Landsat TM imagery,1989 to 2011 (United States)

    Foster, J. R.; D'Amato, A. W.


    Climate change is projected to affect the integrity of forested ecosystems worldwide. One forest type expected to be severely impacted is the eastern spruce-fir forest, because it is already at the extreme elevational and latitudinal limits of its range within the northern United States. Large-scale bioclimactic models predict declining habitat suitability for spruce and fir species, while causing drought and thermal stress on remnant trees. As rising temperatures reduce or eliminate habitat throughout much of the current spruce-fir range, growth and regeneration of hardwood forests or more southerly conifers will be favored. The ecotone between northern hardwood forests and montane boreal forests was recently reported to have shifted approximately 100 m upslope over the last 20-40 years in the Green Mountains of Vermont, U.S.A. The research behind this finding relied on long-term forest plot data and change analysis of narrow transects (6 m width) on aerial photos and SPOT imagery. In the White Mountains of New Hampshire, U.S.A., research using vegetation indices from Landsat data reported a conflicting finding; that coniferous vegetation was increasing downslope of the existing ecotone. We carefully matched and topographically corrected Landsat images from 1989 through 2011 to comprehensively map the boreal-temperate forest ecotone throughout the Green Mountains in Vermont, U.S.A. We used edge detection and linear mixed models to evaluate whether the ecotone changed in elevation over 20 years, and whether rates of change varied with Latitude or aspect. We found that the elevation of the boreal-temperate forest ecotone, and changes in its location over 20 years, were more variable than reported in recent studies. While the ecotone moved to higher elevations in some locations at reported rates, these rates were at the tales of the distribution of elevational change. Other locations showed downward movement of the ecotone, while for the majority of sites, no change

  10. Nitrogen leaching, and nitrogen retention capacity by ectomycorrhizal fungi, in a Norway spruce forest fertilized with nitrogen and phosphorus (United States)

    Wallander, Håkan; Bahr, Adam; Ellström, Magnus; Bergh, Johan


    Ectomycorrhizal (EM) fungi enhance the uptake of nitrogen (N) in boreal forests and get carbohydrates from the trees in exchange. The external mycelium of these fungi explores the soil efficiently and forms a network with a high capacity for N retention. However, when the availability of inorganic N increase the growth of EM mycelia decline, which enhance the risk of N leaching. In the present study we analyzed how fertilization, with N as well as N in combination with phosphorus, affected EM fungal growth and N leaching in a Norway spruce forest in southern Sweden. Additionally, we added 15N labelled NH4+ to mesh bags colonized by EM mycelia to analyze if the amounts taken up by mycelia and the amount that leached through were affected by N fertilization. We found that EM growth declined after N addition and even more so when N was combined with P addition. Nitrogen leaching peaked shortly after fertilization and declined continuously over the experimental period (16 months). Contrary to our expectations, no increase in N leaching occurred during winter and early spring when EM growth was at minimum. We found a large N assimilation capacity of EM mycelium in the mesh bags (0.31 mg 15N g-1 EMF mycelium day-1, SE = 0.03) with no difference between control and fertilized stands. However, a much larger proportion of the recovered 15N (90%) leached through the mycelium in N fertilized forests compared to control stands (50 %), probably due to less abundant EM mycelia. The importance of EM mycelia for N retention in boreal and boreo-nemoral forests will be discussed.

  11. CO2 and heat fluxes in a recently clear-cut spruce forest in European Russia: experimental and modeling studies (United States)

    Mamkin, Vadim; Kurbatova, Julia; Avilov, Vitaly; Mukhartova, Yulia; Krupenko, Alexander; Ivanov, Dmitry; Levashova, Natalia; Olchev, Alexander


    Ecosystem carbon dioxide, energy, and water fluxes were measured using eddy covariance and portable chambers in a fresh clear-cut surrounded by a mixed spruce-birch-aspen forest in the boreal zone of European Russia. Measurements were initiated in spring 2016 following timber harvest and continued for seven months until the end of October. The influence of surrounding forest on air flow and turbulent fluxes within the clear-cut were examined using a process-based two-dimensional (2D) hydrodynamic turbulent exchange model. Clear-cut was a permanent source of CO2 to the atmosphere. During the period the mean daily latent (LE) and sensible (H) heat fluxes were very similar and the Bowen ratio (β=H/LE) averaged about 1.0. During the late spring and summer months the net ecosystem exchange of CO2 (NEE) remained slightly positive following onset of vegetation growth, while β was changing in the range from 0.6 to 4.0. There was strong diurnal variability in NEE, LE and H over the measurement period that was governed by solar radiation and temperature as well as the leaf area index (LAI) of regrown vegetation. Modeled vertical CO2 and H2O fluxes along a transect that crossed the clear-cut and coincided with the dominate wind direction showed that the clear-cut strongly influenced turbulent fluxes within the atmospheric surface layer. Furthermore, modeled atmospheric dynamics suggested that the clear-cut had a large influence on turbulent fluxes in the downwind forest, but little impact on the upwind side. An aggregated approach including field measurements and process-based models can be used to estimate energy, water and carbon dioxide fluxes in non-uniform forest landscapes. This study was supported by a grant from the Russian Science Foundation (14-14-00956).

  12. Detection of spatio-temporal changes of Norway spruce forest stands in Ore Mountains using airborne hyperspectral imagery (United States)

    Misurec, J.; Kopačková, V.; Lhotáková, Z.; Albrechtova, J.; Campbell, P. K. E.


    The Ore Mountains are an example of the region that suffered from severe environmental pollution caused by long-term coal mining and heavy industry leading to massive dieback of the local Norway spruce forests between the 1970's and 1990's. The situation became getting better at the end of 1990's after pollution loads significantly decreased. In 1998 and 2013, airborne hyperspectral data (with sensor ASAS and APEX, respectively) were used to study recovery of the originally damaged forest stands and compared them with those that have been less affected by environmental pollution. The field campaign (needle biochemical analysis, tree defoliation etc.) accompanied hyperspectral imagery acquisition. An analysis was conducted assessing a set of 16 vegetation indices providing complex information on foliage, biochemistry and canopy biophysics and structure. Five of them (NDVI, NDVI705, VOG1, MSR and TCARI/OSAVI) showing the best results were employed to study spatial gradients as well as temporal changes. The detected gradients are in accordance with ground truth data on representative trees. The obtained results indicate that the original significant differences between the damaged and undamaged stands have been generally levelled until 2013, although it is still possible to detect signs of the previous damages in several cases.

  13. Subalpine Conifer Seedling Demographics: Species Responses to Climate Manipulations Across an Elevational Gradient at Niwot Ridge, Colorado (United States)

    Castanha, C.; Germino, M. J.; Torn, M. S.; Ferrenberg, S.; Harte, J.; Kueppers, L. M.


    The effect of climate change on future ranges of treeline species is poorly understood. For example, it is not known whether trees will recruit into the alpine, above the current treeline, and whether population-level differences in trees will mediate range shifts. At Niwot Ridge, Colorado, we used common gardens and climate manipulations to test predictions that warming will lead to greater recruitment at and beyond the cold edge of these species ranges, and will reduce recruitment at the warm edge. Seed from local populations of limber pine and Englemann spruce was harvested and reciprocally planted in 3 experimental sites spanning an elevation gradient from lower subalpine forest (10,000’), to the upper subalpine treeline ecotone (11,000’), to the alpine tundra (11,300’). In Fall 2009 seeds were sown into 20 plots at each site. Overhead infrared heaters targeted increases in growing season surface soil temperature of 4-5°C. The heating treatment, which began in October 2009, was crossed with manual watering, which was initiated following snowmelt in 2010. Over the 2010 growing season, we surveyed seedling germination and mortality weekly. Germination began in early May at the forest site, in early June at the krummholz site, and in early July at the alpine site. Depending on the site and plot, heating accelerated germination by 1 to 4 weeks. Seed source elevation, species, and site all affected germination, with effects for the two species also depending on site. At all sites, lower elevation, warm-edge populations had higher germination rates than high-elevation, cool-edge populations, indicating a potential bottleneck for germination of the high elevation seed sources in the adjacent alpine tundra. At all sites, survival was generally higher for pine than for spruce. Watering tended to enhance pine germinant survival while heating tended to depress spruce germinant survival. Our results indicate that the alpine tundra, generally considered an

  14. Distribution of bioelements in spruce ecosystems of the 'Baerhalde' (Southern Black Forest). Bioelementverteilung in Fichtenoekosystemen der Baerhalde (Suedschwarzwald)

    Energy Technology Data Exchange (ETDEWEB)

    Raisch, W.


    The reserves and distribution of 18 bioelements were determined in five spruce ecosystems (trees and ground vegetation) and in a pasture ecosystem. The spruce stands are 15, 25, 50, 75, and 130 years old. They cover almost a complete rotation cycle as practiced in this altitude. The mean annual increment per hectare varies from 6.6 to 8.3 solid cubic meters of standing crop. This is classified as low, whereas the degree of stocking is high. Twenty six tree compartments and in the ground vegetation the contents of N, P, K, Ca, Mg, Mn, Cu, Zn, Fe, Al, Na, Pb, Cd, Co, Cr, Ni, V, and Be were analysed and the respective dry matter-weights per hectare were calculated. The nutrient supply of the spruce stands was satisfactory for N, K, and Ca, very good for P, but critically short of Mg. Moreover, needle analysis revealed a nutrient deficiency for the micronutrients Zn and Cu. Al levels were high in the spruce needles and correlated with the exchangeable Al of the soils thus reflecting soil conditions. The heavy metals showed different distribution patterns within the ecosystems depending on their mobility in the soils as well as on the immitted far transported depositions into the Black Forest.

  15. Ozone and modeled stomatal conductance at a high elevation subalpine site in southeastern Wyoming (United States)

    Robert C. Musselman; Karl F. Zeller; Nedialko T. Nikolov


    Ozone concentrations have been monitored at the Glacier Lakes Ecosystem Experiment Site (GLEES) in the Snowy Range of the Medicine Bow Mountains 55 km west of Laramie, Wyoming, USA. The site is located at 3,186 m elevation in a large subalpine meadow of a mature subalpine forest near timberline. Continuous ozone and meteorological monitoring are a part of the GLEES...

  16. The influence of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site (United States)

    Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.; Hu, J.; Monson, R. K.


    Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year data set from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation Rnet, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta, specific humidity q, and CO2 dry mole fraction χc). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found the following: (i) even though precipitation caused mean changes on the order of 50-70 % to Rnet, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 90 and 110 %, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10 %), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m-2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m-2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6 % in dry conditions and between 15 and 25 % in partially wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, even though precipitation (and accompanying clouds) reduced the magnitude of Rnet, LE increased from ≈ 10 to over 20 W m-2 due to increased evaporation. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was

  17. The effect of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site (United States)

    Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.; Monson, R. K.


    Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year dataset from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation Rnet, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta, specific humidity q, and CO2 dry mole fraction χc). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found: (i) even though precipitation caused mean changes on the order of 50-70% to Rnet, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 70-80%, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10%), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m-2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m-2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6% in dry conditions and 20% in wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, precipitation (and accompanying clouds) reduced Rnet and increased LE. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was found to be about 2-3 μmol mol-1 larger than χc on dry days. This difference was fairly constant over the full diel cycle

  18. Modeling insect disturbance across forested landscapes: Insights from the spruce budworm (United States)

    Brian R. Sturtevant; Barry J. Cooke; Daniel D. Kneeshaw; David A. MacLean


    Insects are important disturbance agents affecting temperate and boreal biomes (Wermelinger 2004; Johnson et al. 2005; Cooke et al. 2007; Raffa et al. 2008). Defoliating insects in particular have historically affected a staggering area of North American forests, particularly across the boreal biome (Fig. 5.1). Principal among these boreal forest defoliators is the...

  19. Climate drivers of bark beetle outbreak dynamics in Norway spruce forests (United States)

    Lorenzo Marini; Bjorn Okland; Anna Maria Jonsson; Barbara Bentz; Allan Carroll; Beat Forster; Jean-Claude Gregoire; Rainer Hurling; Louis Michel Nageleisen; Sigrid Netherer; Hans Peter Ravn; Aaron Weed; Martin Schroeder


    Bark beetles are among the most devastating biotic agents affecting forests globally and several species are expected to be favored by climate change. Given the potential interactions of insect outbreaks with other biotic and abiotic disturbances, and the potentially strong impact of changing disturbance regimes on forest resources, investigating climatic drivers of...

  20. The lost research of early northeastern spruce-fir experimental forests: a tale of lost opportunities (United States)

    Kate Berven; Laura Kenefic; Aaron Weiskittel; Mark Twery; Jeremy. Wilson


    Long-term research is critical to our understanding of forest dynamics. Observations made over decades or centuries provide valuable insight into the effects of natural and anthropogenic disturbances, and allow scientists and forest managers to determine which management regimes succeed and which ones fail in terms of desired objectives. Unfortunately, many long-term...

  1. Sphagnum mosses limit total carbon consumption during fire in Alaskan black spruce forests (United States)

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


    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...

  2. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests (United States)

    Andrei G. ​Lapenis; Gregory B. Lawrence; Alexander Heim; Chengyang Zheng; Walter. Shortle


    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...

  3. Comparison of Wood Quality of Douglas Fir and Spruce from Afforested Agricultural Land and Permanent Forest Land in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Aleš Zeidler


    Full Text Available This study compares the quality of wood from two distinct sites in the Czech Republic—from former afforested agricultural land and forest land. We compared the properties of Norway spruce wood (Picea abies Karst. and Scots pine wood (Pinus sylvestris L., the most important domestic tree species, to Douglas fir (Pseudotsuga menziesii (Mirbel Franco, a North American tree species and a potential substitute for the domestic spruce. Wood density, modulus of elasticity (MOE, modulus of rupture (MOR and impact bending strength were the properties tested that were used for comparing tree species. Without taking into consideration the site, the highest density values from the tested tree species were obtained for Douglas fir (0.568 g·cm−3, followed by the pine (0.508 g·cm−3 and the spruce (0.463 g·cm−3. The Douglas fir also dominated in the remaining assessed properties, whilst the influence of site was not confirmed, with the exception of MOE and MOR, and only for the Douglas fir wood, wherein higher values were obtained for forest land. In terms assessed Douglas fir properties, it exceeds the domestic softwoods and represents a possible suitable replacement for them. The site only plays a role in terms of the Douglas fir, and only for certain properties.

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

    Directory of Open Access Journals (Sweden)

    Olivier Bouriaud


    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

  5. The historical disturbance regime of mountain Norway spruce forests in the Western Carpathians and its influence on current forest structure and composition. (United States)

    Janda, Pavel; Trotsiuk, Volodymyr; Mikoláš, Martin; Bače, Radek; Nagel, Thomas A; Seidl, Rupert; Seedre, Meelis; Morrissey, Robert C; Kucbel, Stanislav; Jaloviar, Peter; Jasík, Marián; Vysoký, Juraj; Šamonil, Pavel; Čada, Vojtěch; Mrhalová, Hana; Lábusová, Jana; Nováková, Markéta H; Rydval, Miloš; Matějů, Lenka; Svoboda, Miroslav


    In order to gauge ongoing and future changes to disturbance regimes, it is necessary to establish a solid baseline of historic disturbance patterns against which to evaluate these changes. Further, understanding how forest structure and composition respond to variation in past disturbances may provide insight into future resilience to climate-driven alterations of disturbance regimes. We established 184 plots (mostly 1000 m 2 ) in 14 primary mountain Norway spruce forests in the Western Carpathians. On each plot we surveyed live and dead trees and regeneration, and cored around 25 canopy trees. Disturbance history was reconstructed by examining individual tree growth trends. The study plots were further aggregated into five groups based on disturbance history (severity and timing) to evaluate and explain its influence on forest structure. These ecosystems are characterized by a mixed severity disturbance regime with high spatiotemporal variability in severity and frequency. However, periods of synchrony in disturbance activity were also found. Specifically, a peak of canopy disturbance was found for the mid-19th century across the region (about 60% of trees established), with the most important periods of disturbance in the 1820s and from the 1840s to the 1870s. Current stand size and age structure were strongly influenced by past disturbance activity. In contrast, past disturbances did not have a significant effect on current tree density, the amount of coarse woody debris, and regeneration. High mean densities of regeneration with height >50 cm (about 1400 individuals per ha) were observed. Extensive high severity disturbances have recently affected Central European forests, spurring a discussion about the causes and consequences. We found some evidence that forests in the Western Carpathians were predisposed to recent severe disturbance events as a result of synchronized past disturbance activity, which partly homogenized size and age structure and made recent

  6. Habitat Quality Assessment of Herb-rich Spruce Forests in Estonia

    Directory of Open Access Journals (Sweden)

    H. Korjus


    Full Text Available The Natura 2000 network contains many different habitats in Estonia, including old-growth forests and semi-natural woodlands. Ten years after the establishment of the Natura 2000 network in Estonia, changes have occurred in habitat type and habitat quality. Vegetation composition as well as the structural and functional qualities of a forest habitat type – Fennoscandian herbrich forests with Picea abies (EU Habitats Directive habitat type 9050 – are analysed in this study. The study is based on sample plots measured in 2014 and are located in protected and non-protected areas. Aegopodium, Filipendula and Oxalis vegetation types are included for assessment of vegetation, tree structure and deadwood composition. Habitat composition and dynamics on conservation sites are compared with commercial forests and possible ecosystem restoration measures are discussed in the study. The 46% of the studied habitats had considerably lowered their initial conservation value and 49% were developed towards habitat type 9010 during 2004–2014.

  7. Dynamics of understory biomass in Sitka spruce-western hemlock forests of southeast Alaska (United States)

    US Fish and Wildlife Service, Department of the Interior — Several understory communities display successional stages during the first 200 years after logging or fire disturbance in the Coastal Picea-Tsuga forests of...

  8. Non-Host Volatile Blend Optimization for Forest Protection against the European Spruce Bark Beetle, Ips typographus (United States)

    Unelius, C. Rikard; Schiebe, Christian; Bohman, Björn; Andersson, Martin N.; Schlyter, Fredrik


    Conifer feeding bark beetles (Coleoptera, Curculionidae, Scolytinae) pose a serious economic threat to forest production. Volatiles released by non-host angiosperm plants (so called non-host volatiles, NHV) have been shown to reduce the risk of attack by many bark beetle species, including the European spruce bark beetle, Ips typographus. However, the most active blend for I. typographus, containing three green leaf volatiles (GLVs) in addition to the key compounds trans-conophthorin (tC) and verbenone, has been considered too expensive for use in large-scale management. To lower the cost and improve the applicability of NHV, we aim to simplify the blend without compromising its anti-attractant potency. Since the key compound tC is expensive in pure form, we also tested a crude version: technical grade trans-conophthorin (T-tC). In another attempt to find a more cost effective substitute for tC, we evaluated a more readily synthesized analog: dehydro-conophthorin (DHC). Our results showed that 1-hexanol alone could replace the three-component GLV blend containing 1-hexanol, (3Z)-hexen-1-ol, and (2E)-hexen-1-ol. Furthermore, the release rate of tC could be reduced from 5 mg/day to 0.5 mg/day in a blend with 1-hexanol and (–)-verbenone without compromising the anti-attractant activity. We further show that T-tC was comparable with tC, whereas DHC was a less effective anti-attractant. DHC also elicited weaker physiological responses in the tC-responding olfactory receptor neuron class, providing a likely mechanistic explanation for its weaker anti-attractive effect. Our results suggest a blend consisting of (–)-verbenone, 1-hexanol and technical trans-conophthorin as a cost-efficient anti-attractant for forest protection against I. typographus. PMID:24454855

  9. Non-host volatile blend optimization for forest protection against the European spruce bark beetle, Ips typographus.

    Directory of Open Access Journals (Sweden)

    C Rikard Unelius

    Full Text Available Conifer feeding bark beetles (Coleoptera, Curculionidae, Scolytinae pose a serious economic threat to forest production. Volatiles released by non-host angiosperm plants (so called non-host volatiles, NHV have been shown to reduce the risk of attack by many bark beetle species, including the European spruce bark beetle, Ips typographus. However, the most active blend for I. typographus, containing three green leaf volatiles (GLVs in addition to the key compounds trans-conophthorin (tC and verbenone, has been considered too expensive for use in large-scale management. To lower the cost and improve the applicability of NHV, we aim to simplify the blend without compromising its anti-attractant potency. Since the key compound tC is expensive in pure form, we also tested a crude version: technical grade trans-conophthorin (T-tC. In another attempt to find a more cost effective substitute for tC, we evaluated a more readily synthesized analog: dehydro-conophthorin (DHC. Our results showed that 1-hexanol alone could replace the three-component GLV blend containing 1-hexanol, (3Z-hexen-1-ol, and (2E-hexen-1-ol. Furthermore, the release rate of tC could be reduced from 5 mg/day to 0.5 mg/day in a blend with 1-hexanol and (--verbenone without compromising the anti-attractant activity. We further show that T-tC was comparable with tC, whereas DHC was a less effective anti-attractant. DHC also elicited weaker physiological responses in the tC-responding olfactory receptor neuron class, providing a likely mechanistic explanation for its weaker anti-attractive effect. Our results suggest a blend consisting of (--verbenone, 1-hexanol and technical trans-conophthorin as a cost-efficient anti-attractant for forest protection against I. typographus.

  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 (United States)

    Paul G. Schaberg; Gary J. Hawley


    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. Sensitivity and predictive uncertainty of the ACASA model at a spruce forest site

    Directory of Open Access Journals (Sweden)

    K. Staudt


    Full Text Available The sensitivity and predictive uncertainty of the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA was assessed by employing the Generalized Likelihood Uncertainty Estimation (GLUE method. ACASA is a stand-scale, multi-layer soil-vegetation-atmosphere transfer model that incorporates a third order closure method to simulate the turbulent exchange of energy and matter within and above the canopy. Fluxes simulated by the model were compared to sensible and latent heat fluxes as well as the net ecosystem exchange measured by an eddy-covariance system above the spruce canopy at the FLUXNET-station Waldstein-Weidenbrunnen in the Fichtelgebirge Mountains in Germany. From each of the intensive observation periods carried out within the EGER project (ExchanGE processes in mountainous Regions in autumn 2007 and summer 2008, five days of flux measurements were selected. A large number (20000 of model runs using randomly generated parameter sets were performed and goodness of fit measures for all fluxes for each of these runs were calculated. The 10% best model runs for each flux were used for further investigation of the sensitivity of the fluxes to parameter values and to calculate uncertainty bounds.

    A strong sensitivity of the individual fluxes to a few parameters was observed, such as the leaf area index. However, the sensitivity analysis also revealed the equifinality of many parameters in the ACASA model for the investigated periods. The analysis of two time periods, each representing different meteorological conditions, provided an insight into the seasonal variation of parameter sensitivity. The calculated uncertainty bounds demonstrated that all fluxes were well reproduced by the ACASA model. In general, uncertainty bounds encompass measured values better when these are conditioned on the respective individual flux only and not on all three fluxes concurrently. Structural weaknesses of the ACASA model concerning the soil respiration

  12. Modeling Nitrous Oxide emissions and identifying emission controlling factors for a spruce forest ecosystem on drained organic soil (United States)

    He, Hongxing; Kasimir, Åsa; Jansson, Per-Erik; Svensson, Magnus; Meyer, Astrid; Klemedtsson, Leif


    High Nitrous Oxide (N2O) emission has been identified in hemiboreal forests on drained organic soils. However, the controlling factors regulating the emissions have been unclear. To examine the importance of different factors on the N2O emission in a spruce forest on drained organic soil, a process-based model, CoupModel, was calibrated by the generalized likelihood uncertainty estimation (GLUE) method. The calibrated model reproduced most of the high resolution data (total net radiation, soil temperature, groundwater level, net ecosystem exchange, etc.) very well, as well as accumulated measured N2O emissions, but showed difficulties to capture all the measured emission peaks. Parameter uncertainties could be reduced by combining selected criteria with the measurement data. The model showed the N2O emissions during the summer to be controlled mainly by the competition between plants and microbes while during the winter season snow melt periods are important. The simulated N budget shows >100 kg N ha-1 yr-1 to be in circulation between soil and plants and back again. Each year the peat mineralization adds about 60 kg N ha-1 and atmospheric deposition 12 kg N ha-1. Most of the mineralized litter and peat N is directly taken up by the plants but only a part accumulates in the plant biomass. As long as no timber is harvested the main N loss from the system is through nitrate leaching (30 kg N ha-1 yr-1) and gas emissions (20 kg N ha-1 yr-1), 55% as NO, 27% as N2O and 18% as N2. Regarding N2O gas emissions, our modeling indicates denitrification to be the most responsible process, of the size 6 kg N ha-1 yr-1, which could be compared to 0.04 kg N ha-1 yr-1 from nitrification. Our modelling also reveal 88% of the N2O mainly to be produced by denitrification in the capillary fringe (c.a. 40-60 cm below soil surface) of the anaerobic zone using nitrate produced in the upper more aerobic layers. We conclude N2O production/emission to be controlled mainly by the complex

  13. Ponderosa pine, mixed conifer, and spruce-fir forests [Chapter 2 (United States)

    Michael A. Battaglia; Wayne D. Shepperd


    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...

  14. Soil moisture sensitivity of autotrophic and heterotrophic forest floor respiration in boreal xeric pine and mesic spruce forests (United States)

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


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

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

    National Research Council Canada - National Science Library

    Andrew D Cameron


    .... 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...

  16. Mean wind patterns and snow depths in an alpine-subalpine ecosystem as measured by damage to coniferous trees (United States)

    G. L. Wooldridge; R. C. Musselman; R. A. Sommerfeld; D. G. Fox; B. H. Connell


    1. Deformations of Engelmann spruce and subalpine fir trees were surveyed for the purpose of determining climatic wind speeds and directions and snow depths in the Glacier Lakes Ecosystem Experiments Site (GLEES) in the Snowy Range of southeastern Wyoming, USA. Tree deformations were recorded at 50- and 100-m grid intervals over areas of c. 30 ha and 300 ha,...

  17. 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


    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...

  18. Comparing the impacts of mature spruce forests and grasslands on snow melt, water resource recharge, and run-off in the northern boreal environment

    Directory of Open Access Journals (Sweden)

    Jiří Kremsa


    Full Text Available Snow-melt runoff is an important factor in control of flooding and soil erosion in higher and cold regions of the world. In 1992–2008–2008, processes of snow accumulation and melting were monitored at two adjacent sites of the Paljakka environmental research centre (Finland. The forest stand of mature spruce (Picea abies has been compared with adjacent, local, and open grassland. In the forest, snowpack duration fluctuated for 180–245 days, with a maximum depth of 78–152 cm and snow–water content of 167–406 mm, while in the open grassland this occurred for some 20 days less, with maximum depth 65–122 cm, and snow–water content 143–288 mm. The snow–water captured in the canopy reached a maximum 27% of that registered on the ground; the loss of intercepted snow by sublimation was approximately 26% of the annual snowfall. During the high melt period (April–May, the degree-day factor in the forest stand achieved 60% of values observed in the grassland (2.3–3.5 against 3.8–6.0 mm °C−1 day−1. The hydrological model BROOK 90 was employed to analyse potential water resources recharge, and flood risk at Paljakka. Considering the normal climate season, snow-melt runoff from the forest exceeded the grassland by 22% (225 against 185 mm. In extreme situations, the maximum daily runoff from snow-melt in the grasslands (57 mm day−1 exceeded 2.6 times the values in spruce forest (22 mm day−1.

  19. 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


    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.

  20. Spruce aphid, Elatobium abietinum (Walker): Life history and damage to Engelmann spruce in the Pinaleno Mountains, Arizona (United States)

    Ann M. Lynch


    Spruce aphid is an exotic insect recently introduced to the Pinaleno Mountains. It feeds on dormant Engelmann spruce, and possible effects include tree-growth suppression, tree mortality, and reduction in seed and cone production. Potential longer-term effects include changes in forest structure and species composition - primarily through reduction in Engelmann spruce...

  1. Types of ectomycorrhiza of mature beech and spruce at ozone-fumigated and control forest plots. (United States)

    Grebenc, Tine; Kraigher, Hojka


    In the Kranzberg forest near Freising (Germany) a novel "Free-Air Canopy O3 Exposure" system has been employed for analysing O3-induced responses from sub-cellular to ecosystem levels that are relevant for carbon balance and CO2 demand of 60-year-old beech trees. The below-ground ectomycorrhizal community was studied in two-fold ambient O3 concentrations (five cores per sampling) and in a control plot with an ambient O3 concentration (four cores per sampling). Five samplings were taken throughout two vegetation seasons (2003 and 2004). Types of ectomycorrhiza were determined by their morphological, anatomical and molecular characteristics and quantified by counting. The total number of mycorrhizal fine roots was higher at the fumigated plot as compared with the control site. The numbers of ectomycorrhizal types at the fumigated and control plots were 28 and 26, respectively. Cenococcum geophilum was present in all soil cores at all sampling times with a significant increase in abundance under ozone-fumigated trees. Other mycorrhizal types present at higher abundance at the fumigated than at the control plot were identified as Russula densiflora, R. fellea, R. illota, Tuber puberulum, Lactarius sp. 2 and Russula sp. 2. Some mycorrhizal types were present exclusively at the fumigated plot (Fagirhiza fusca, F. setifera, Lactarius acris, Piceirhiza nigra and Russula sp. 1). A possible ecological role for the abundant types of ectomycorrhiza and their putative application in bio-indication is discussed.

  2. 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 (United States)

    Gerard, tech. coord. Hertel; Gerard Hertel


    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.

  3. Leap frog in slow motion: Divergent responses of tree species and life stages to climatic warming in Great Basin subalpine forests. (United States)

    Smithers, Brian V; North, Malcolm P; Millar, Constance I; Latimer, Andrew M


    In response to climate warming, subalpine treelines are expected to move up in elevation since treelines are generally controlled by growing season temperature. Where treeline is advancing, dispersal differences and early life stage environmental tolerances are likely to affect how species expand their ranges. Species with an establishment advantage will colonize newly available habitat first, potentially excluding species that have slower establishment rates. Using a network of plots across five mountain ranges, we described patterns of upslope elevational range shift for the two dominant Great Basin subalpine species, limber pine and Great Basin bristlecone pine. We found that the Great Basin treeline for these species is expanding upslope with a mean vertical elevation shift of 19.1 m since 1950, which is lower than what we might expect based on temperature increases alone. The largest advances were on limber pine-dominated granitic soils, on west aspects, and at lower latitudes. Bristlecone pine juveniles establishing above treeline share some environmental associations with bristlecone adults. Limber pine above-treeline juveniles, in contrast, are prevalent across environmental conditions and share few environmental associations with limber pine adults. Strikingly, limber pine is establishing above treeline throughout the region without regard to site characteristic such as soil type, slope, aspect, or soil texture. Although limber pine is often rare at treeline where it coexists with bristlecone pine, limber pine juveniles dominate above treeline even on calcareous soils that are core bristlecone pine habitat. Limber pine is successfully "leap-frogging" over bristlecone pine, probably because of its strong dispersal advantage and broader tolerances for establishment. This early-stage dominance indicates the potential for the species composition of treeline to change in response to climate change. More broadly, it shows how species differences in dispersal

  4. Calcium addition at the Hubbard Brook Experimental Forest increases sugar storage, antioxidant activity and cold tolerance in native red spruce (Picea rubens). (United States)

    Halman, Joshua M; Schaberg, Paul G; Hawley, Gary J; Eagar, Christopher


    In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO(3), a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition watershed) at the Hubbard Brook Experimental Forest (Thornton, NH). We analyzed nutrition, soluble sugar concentrations, ascorbate peroxidase (APX) activity and cold tolerance, to evaluate the basis of recent (2003) differences between watersheds in red spruce foliar winter injury. Foliar Ca and total sugar concentrations were significantly higher in trees in the Ca-addition watershed than in trees in the reference watershed during both fall (P=0.037 and 0.035, respectively) and winter (P=0.055 and 0.036, respectively). The Ca-addition treatment significantly increased foliar fructose and glucose concentrations in November (P=0.013 and 0.007, respectively) and foliar sucrose concentrations in winter (P=0.040). Foliar APX activity was similar in trees in both watersheds during fall (P=0.28), but higher in trees in the Ca-addition watershed during winter (P=0.063). Cold tolerance of foliage was significantly greater in trees in the Ca-addition watershed than in trees in the reference watershed (P<0.001). Our results suggest that low foliar sugar concentrations and APX activity, and reduced cold tolerance in trees in the reference watershed contributed to their high vulnerability to winter injury in 2003. Because the reference watershed reflects forest conditions in the region, the consequences of impaired physiological function caused by soil Ca depletion may have widespread implications for forest health.

  5. Vitality and chemistry of roots of red spruce in forest floors of stands with a gradient of soil Al/Ca ratios in the northeastern United States (United States)

    Wargo, P.M.; Vogt, K.; Vogt, D.; Holifield, Q.; Tilley, J.; Lawrence, G.; David, M.


    Number of living root tips per branch, percent dead roots, percent mycorrhizae and mycorrhizal morphotype, response of woody roots to wounding and colonization by fungi, and concentrations of starch, soluble sugars, phenols, percent C and N and C/N ratio, and Al Ca, Fe, K, Mg, Mn, and P were measured for 2 consecutive years in roots of red spruce (Picea rubens Sarg.) in stands in the northeastern United States (nine in 1993 and two additional in 1994) dominated by red spruce and with a gradient of forest floor exchangeable Al/Ca ratios. Root vitality was measured for nonwoody and coarse woody roots; chemical variables were measured for nonwoody (<1 mm), fine woody (1 to <2 mm), and coarse woody (2 to <5 mm) roots. There were significant differences among sites for all variables, particularly in 1993, although few were related to the Al/Ca ratio gradient. Percent mycorrhizae decreased, while some morphotypes increased or decreased as the Al/Ca ratio increased. In nonwoody roots, N increased as the Al/Ca ratio increased. Most sampled trees appeared to be in good or fair health, suggesting that an adverse response of these root variables to high Al concentrations may be apparent only after a significant change in crown health.

  6. 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


    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

  7. Phenolic compounds as a tool of bioindication for novel forest decline at numerous spruce tree sites in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Richter, C.M. [Mainz Univ. (Germany). Inst. fuer Allgemeine Botanik; Eis, U. [Mainz Univ. (Germany). Inst. fuer Allgemeine Botanik; Wild, A. [Mainz Univ. (Germany). Inst. fuer Allgemeine Botanik


    Within a project that applied biochemical criteria to the diagnosis of damage to Norway spruce, 43 sites in western and eastern Germany showing only moderate tree damage were screened for the amounts of methanol soluble phenolic compounds in spruce needles. The concentrations of most of the main compounds - especially catechin - positively correlated with needle loss and the altitude of the site. It was also found that it is necessary to differentiate between trees younger and older than 60 years of age. The correlations between the increase of the phenolic compounds studied and the needle loss or the damage class are stronger in the younger trees, possibly implicating differences in metabolic state or disturbances in protectective mechanisms in the older trees. (orig.)

  8. An analytical method to assess spruce beetle impacts on white spruce resources, Kenai Peninsula, Alaska. (United States)

    Willem W.S. van Hees


    Forest inventory data collected in 1987 fTom sample plots established on the Kenai Peninsula were analyzed to provide point-in-time estimates of the trend and current status of a spruce beetle infestation. Ground plots were categorized by stage of infestation. Estimates of numbers of live and dead white spruce trees, cubic-foot volume in those trees, and areal extent...

  9. Response of the engraver beetle, IPS perturbatus, to semiochemicals in white spruce stands of interior Alaska. Forest Service research paper

    Energy Technology Data Exchange (ETDEWEB)

    Werner, R.A.


    Field tests on the efficacy of various scolytid bark beetle pheromones to attract Ips perturbatus (Eichhoff) were conducted from 1977 through 1992 in stands of white spruce (Picea glauca (Moench) Voss) in interior Alaska. Several pheromones attracted high numbers of I. perturbatus and species of the predator Thanasimus to baited funnel traps. Test results also indicated that attacks by I. perturbatus may be deferred by certain semiochemicals.

  10. Effect of industrial emissions with high sulphur dioxide content on thiobacilli and oxidative activity of spruce forest soils towards inorganic sulphur compounds. (United States)

    Lettl, A; Langkramer, O; Lochman, V; Jaks, M


    Effect of industrial emissions with high sulphur dioxide content on the upper horizons of spruce forest soils in NW Bohemia was investigated. The content of sulphates, oxidative activity towards sulphide, elemental sulphur, thiosulphate and sulphite, concentration and species representation of thiobacilli in horizons F, H and A in regions highly affected by emissions (two localities) and in regions relatively less influenced (three localities) were followed. In the affected areas the sulphur content in the soil was higher, the species representation of thiobacilli was similar and their concentration was higher, the ability of the soil to oxidize thiosulphate was inhibited and oxidation of elemental sulphur was stimulated. The oxidation of sulphide and sulphite was not significantly affected by the emissions. Changes caused by emissions could be observed only in horizons F and H and did not involve horizons A.

  11. Integrated permanent plot and aerial monitoring for the spruce budworm decision support system (United States)

    David A. MacLean


    Spruce budworm (Choristoneura fumiferana Clem.) outbreaks cause severe mortality and growth loss of spruce and fir forest over ranch of eastern North America. The Spruce Budworm Decision Support System (DSS) links prediction and interpretation models to the ARC/1NFO GIS, under an ArcView graphical user interface. It helps forest managers predict...

  12. Spruce reproduction dynamics on Alaska's Kenai Peninsula, 1987-2000. (United States)

    Willem W.S. van Hees


    During the past 30 years, spruce forests of Alaska’s Kenai Peninsula have undergone dramatic changes resulting from widespread spruce bark beetle(Dendroctonus rufipennis (Kirby)) infestation. In 1987 and again in 2000, the Pacific Northwest Research Station's Forest Inventory and Analysis Program conducted initial and remeasurement inventories...

  13. Growth response to a changing environment-Impacts of tropospheric ozone dose on photosynthesis of Norway spruce forests in Austria (United States)

    Liu, Xiaozhen; Pietsch, Stephan; Hasenauer, Hubert


    Tropospheric ozone is an important air pollutant, although plants have active defense strategies (e.g. antioxidants), the cumulative ozone dose may lead to chronic damages to plant tissues. Ozone enters into plants through stomata and reacts with other chemicals to create toxic compounds. This affects plant photosynthesis and may reduce CO2 fixation, and consequently growth. Open top cambers (OTC) are usually used to study the effects of elevated ozone levels on photosynthesis; whereas field studies with on site occurring ozone levels are rare. A recent modelling study on Norway spruce stands in Austria exhibited trends in model errors indicating that an increase in ozone dose leads to a reduction in volume increment. This study aims to explore how different ozone doses affect photosynthesis under field conditions and may translate into growth response for 12 stands of Norway spruce, distributed along an ozone concentration gradient across Austria. A LI-6400xt photosynthesis system was utilized to collect physiological parameters including net photosynthesis, stomata conductance, internal CO2 concentration, transpiration, etc. Chlorophyll fluorescence data was collected by using a PEA chlorophyll fluorescence meter, and chlorophyll content was measured. Morphological characteristics and soil samples were also analyzed. Ozone dose to leaf tissue was calculated from external ozone concentration, the conductance of the stomata to ozone, the leaf area index and the time span of the day when ozone uptake takes place. Our results confirm that increasing cumulative ozone dose reduces maximum assimilation rate and carboxylation efficiency under field conditions. Our final goal is to quantify how far this ozone induced reduction in assimilation power ultimately translates into a growth reduction of Norway spruce in Austria.

  14. 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


    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

  15. Pollutant effects on the conformation of chlorophyll-protein complexes in forest trees suffering from air pollutant stress. Pt. 2. Pigment content and characteristics of the light-harvesting chlorophyll-a/b-protein complex in needles of healthy and damaged spruce trees in the area Kaelbelescheuer (Southern Black Forest)

    Energy Technology Data Exchange (ETDEWEB)

    Siefermann-Harms, D.; Ninnemann, H.; Horsch, F.; Filby, G.; Fund, N.; Gross, S.; Hanisch, B.; Kilz, E.; Seidel, A. (comps.)


    Symptoms of the forest decline type 'photobleaching in higher altitudes' are studied with spruce trees, Picea abies (L.) Karst., growing in a clean-air area. The pigment content in 1- and 2-year old needles of spruce tree 'No. 5' (strongly damaged; 70% of needles, mainly the older ones, lost) is reduced as compared with 2 healthy controls. Chl-a, Chl-b, carotene, violaxanthin and neoxanthin are lowered at similar degree, while lutein shows little change. The same pattern of pigment bleaching is observed in light-exposed 3-year old needles of spruce tree 'No. 22' (strongly damaged; 30% of needles lost) while no bleaching is observed in 3-year old shaded needles of the same tree. The pattern of pigment bleaching observed in the damaged trees differs from that induced by exposing spruce trees to chloroethenes. The light-harvesting Chl-a/b-protein (LHC) isolated from needles of spruce No. 5 or from shaded needles of spruce No. 22 is less stable under acidic conditions than LHCs from healthy controls. This observation points at some conformational change occurring in LHCs of the damaged trees. Since a decreased acid stability is observed for the LHC from shaded needles of tree 22 the pigments of which are not bleached, we consider that some conformational change of the LHC might precede light-induced pigment bleaching.

  16. Ecology of whitebark pine populations in relation to white pine blister rust infection in subalpine forests of the Lake Tahoe Basin: Implications for restoration (United States)

    Patricia E. Maloney; Detlev R. Vogler; Camille E. Jensen; Annette. Delfino Mix


    For over a century, white pine blister rust (WPBR), caused by the introduced fungal pathogen, Cronartium ribicola J.C. Fisch., has affected white pine (Subgenus Strobus) individuals, populations, and associated forest communities in North America. We surveyed eight populations of whitebark pine (Pinus albicaulis Engelm.) across a range of environmental conditions in...

  17. 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.


    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

  18. Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data (United States)

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


    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

  19. Modeling fire severity in black spruce stands in the Alaskan boreal forest using spectral and non-spectral geospatial data (United States)

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


    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

  20. Post-fire forest dynamics and climate variability affect spatial and temporal properties of spruce beetle outbreaks on a Sky Island mountain range (United States)

    Christopher D. O' Connor; Ann M. Lynch; Donald A. Falk; Thomas W. Swetnam


    The spruce beetle (Dendroctonus rufipennis) is known for extensive outbreaks resulting in high spruce mortality, but several recent outbreaks in the western United States have been among the largest and most severe in the documentary record. In the Pinaleño Mountains of southeast Arizona, U.S.A., an outbreak in the mid-1990s resulted in 85% mortality of Engelmann...

  1. 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 (United States)

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


    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...

  2. Foliar Phenolic Compounds in Norway Spruce with Varying Susceptibility to Chrysomyxa rhododendri: Analyses of Seasonal and Infection-Induced Accumulation Patterns

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    Andrea Ganthaler


    Full Text Available Secondary phenolic metabolites are involved in plant responses to various biotic stress factors, and are apparently important for the defense against fungal pathogens. In this study, we investigated their role in defense against the rust Chrysomyxa rhododendri in Norway spruce. The fungal pathogen undergoes a seasonal lifecycle with host shift; after overwintering in rhododendron shrubs, it attacks the sprouting current-year spruce needles and causes needle fall in autumn. Repeated infections lead to reduced timber yield and severe problems with rejuvenation in subalpine Norway spruce forests. Trees with varying susceptibility to infection by C. rhododendri were selected and foliar phenolic composition was assessed using UHPLC-MS. We report on seasonal accumulation patterns and infection-related changes in the concentrations of 16 metabolites, including flavonoids, stilbenes, simple phenylpropanoids and the precursor shikimic acid, and their correlation with the infection degree of the tree. We found significant variation in the phenolic profiles during needle development: flavonoids were predominant in the first weeks after sprouting, whereas stilbenes, picein and shikimic acid increased during the first year. Following infection, several flavonoids and resveratrol increased up to 1.8 fold in concentration, whereas picein and shikimic acid were reduced by about 70 and 60%, respectively. The constitutive and early stage infection-induced concentrations of kaempferol, quercetin and taxifolin as well as the late stage infection-induced concentrations of stilbenes and picein were negatively correlated with infection degree. We conclude that a combination of constitutive and inducible accumulation of phenolic compounds is associated with the lower susceptibility of individual trees to C. rhododendri. The potentially fungicidal flavonoid aglycones may limit hyphal growth and prevent development of infection symptoms, and high levels of stilbenes may

  3. Foliar Phenolic Compounds in Norway Spruce with Varying Susceptibility to Chrysomyxa rhododendri: Analyses of Seasonal and Infection-Induced Accumulation Patterns (United States)

    Ganthaler, Andrea; Stöggl, Wolfgang; Kranner, Ilse; Mayr, Stefan


    Secondary phenolic metabolites are involved in plant responses to various biotic stress factors, and are apparently important for the defense against fungal pathogens. In this study, we investigated their role in defense against the rust Chrysomyxa rhododendri in Norway spruce. The fungal pathogen undergoes a seasonal lifecycle with host shift; after overwintering in rhododendron shrubs, it attacks the sprouting current-year spruce needles and causes needle fall in autumn. Repeated infections lead to reduced timber yield and severe problems with rejuvenation in subalpine Norway spruce forests. Trees with varying susceptibility to infection by C. rhododendri were selected and foliar phenolic composition was assessed using UHPLC-MS. We report on seasonal accumulation patterns and infection-related changes in the concentrations of 16 metabolites, including flavonoids, stilbenes, simple phenylpropanoids and the precursor shikimic acid, and their correlation with the infection degree of the tree. We found significant variation in the phenolic profiles during needle development: flavonoids were predominant in the first weeks after sprouting, whereas stilbenes, picein and shikimic acid increased during the first year. Following infection, several flavonoids and resveratrol increased up to 1.8 fold in concentration, whereas picein and shikimic acid were reduced by about 70 and 60%, respectively. The constitutive and early stage infection-induced concentrations of kaempferol, quercetin and taxifolin as well as the late stage infection-induced concentrations of stilbenes and picein were negatively correlated with infection degree. We conclude that a combination of constitutive and inducible accumulation of phenolic compounds is associated with the lower susceptibility of individual trees to C. rhododendri. The potentially fungicidal flavonoid aglycones may limit hyphal growth and prevent development of infection symptoms, and high levels of stilbenes may impede the infection

  4. Commercial Thinning to Meet Wood Production Objectives and Develop Structural Heterogeneity: A Case Study in the Spruce-Fir Forest, Quebec, Canada

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    Martin-Michel Gauthier


    Full Text Available We evaluated the effectiveness of commercial thinning mainly from below (CT; 0, 26%, 32% and 40% merchantable basal area removals in meeting wood production demands and developing structural heterogeneity in a balsam fir (Abies balsamea (L. Mill and spruce (Picea spp. stand. After 10 years, 32%–40% removals showed a 12%–18% increase in mean diameter and 27%–38% increase in gross merchantable volume (GMV per tree compared to the unthinned control. At the stand level, all thinning treatments generated as much cumulative GMV (harvested volume + GMV after 10 years and gross sawlog volume per hectare as the unthinned control. As for stand structure, eight out of nine thinned experimental units showed increased structural heterogeneity after 10 years, i.e., irregular, positively-skewed diameter distribution with an elongated right tail toward larger trees. The diameter distribution in the unthinned control became more symmetric, unimodal and regular over time, with fewer saplings than at the beginning of the experiment and lower density of larger trees compared to CT. Regeneration density and stocking were abundant in all treatments, largely dominated by balsam fir. Results indicate that thinning can be used to meet wood production objectives and help develop structural heterogeneity in this forest.

  5. Relation of Chlorophyll Fluorescence Sensitive Reflectance Ratios to Carbon Flux Measurements of Montanne Grassland and Norway Spruce Forest Ecosystems in the Temperate Zone

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    Alexander Ač


    Full Text Available We explored ability of reflectance vegetation indexes (VIs related to chlorophyll fluorescence emission (686/630, 740/800 and de-epoxidation state of xanthophyll cycle pigments (PRI, calculated as (531−570/(531−570 to track changes in the CO2 assimilation rate and Light Use Efficiency (LUE in montane grassland and Norway spruce forest ecosystems, both at leaf and also canopy level. VIs were measured at two research plots using a ground-based high spatial/spectral resolution imaging spectroscopy technique. No significant relationship between VIs and leaf light-saturated CO2 assimilation (MAX was detected in instantaneous measurements of grassland under steady-state irradiance conditions. Once the temporal dimension and daily irradiance variation were included into the experimental setup, statistically significant changes in VIs related to tested physiological parameters were revealed. ΔPRI and Δ(686/630 of grassland plant leaves under dark-to-full sunlight transition in the scale of minutes were significantly related to MAX (2=0.51. In the daily course, the variation of VIs measured in one-hour intervals correlated well with the variation of Gross Primary Production (GPP, Net Ecosystem Exchange (NEE, and LUE estimated via the eddy-covariance flux tower. Statistical results were weaker in the case of the grassland ecosystem, with the strongest statistical relation of the index 686/630 with NEE and GPP.

  6. Localized Effects of Coarse Woody Material on Soil Oribatid Communities Diminish over 700 Years of Stand Development in Black-Spruce-Feathermoss Forests

    Directory of Open Access Journals (Sweden)

    Enrique Doblas-Miranda


    Full Text Available In the black-spruce clay-belt region of Western Québec, soil nutrients are limited due to paludification. Under paludified conditions, nutrient subsidies from decomposing surface coarse woody material (CWM may be important particularly during the later stages of ecosystem development when deadwood from senescent trees has accumulated. For soil organisms, CWM can alter microclimatic conditions and resource availability. We compared abundance and species richness of oribatid mites below or adjacent to CWM across a chronosequence which spans ca. 700 years of stand development. We hypothesized that oribatid abundance and richness would be greater under the logs, particularly in later stages of forest development when logs may act as localized sources of carbon and nutrients in the paludified substrate. However, oribatid density was lower directly under CWM than adjacent to CWM but these differences were attenuated with time. We suggest that oribatids may be affected by soil compaction and also that such microarthropods are most likely feeding on recently fallen leaf litter, which may be rendered inaccessible by the presence of overlying CWM. This may also explain the progressive decline in oribatid density and diversity with time, which are presumably caused by decreases in litter availability due to self-thinning and Sphagnum growth. This is also supported by changes of different oribatid trophic groups, as litter feeders maintain different numbers relative to CWM with time while more generalist fungi feeders only show differences related to position in the beginning of the succession.

  7. Drivers of variability in water use of two co-occurring species in a subalpine forest in Jiuzhaigou Valley, Southwest of China (United States)

    Yan, C.; Zhao, W.; Wang, Y.; Zhang, Q.; Qiu, G. Y.


    Co-occur species with different sensitivity to soil water may be particularly useful in evaluating water use by different forest stands as well as the response of species distribution, forest structure and stand composition to soil water availability in water-limited area. To clarify the species-specific water use strategy and provide insights into the possible succession trend, variations in sap flow and environmental conditions were investigated for two co-occur species (Betula albo-sinensis and Pinus tabulaeformis) in a mixed forest in Jiuzhaigou Valley in 2014. Sap flow was measured by Granier-type thermal dissipation probes and soil water content was measured by time-domain reflectometry probes for a successive period. Pinus tabulaeformis and Betua albo-sinensis species showed different responses to meteorological factors under different soil water conditions. Despite that whole tree water use was much higher for Pinus tabulaeformis due to greater sapwood area, sap flux density of the other co-occurring species Betua albo-sinensis was higher throughout the growing season. Normalized sap flux density (Fd) could be mostly well fitted to solar radiation (Rs), vapor pressure deficit (VPD), or the variable of transpiration (VT) by the exponential saturation function. Much better fitted curves were found for Fd -VPD and Fd - VT datasets than Fd - Rs datasets. For most datasets, normalized Fd increased rapidly when the environmental factors were below their threshold values, but reached an asymptote thereafter. Based on the species' differences in fitting parameters and the average maximum sap flow level under different soil water conditions, it was concluded that Pinus tabulaeformis was sensitive to soil water conditions and tolerant of low soil water availability, while Betua albo-sinensis was insensitive to soil moisture and needed to access to similarly high amount of soil water in the growing season after leaf expansion. These results indicated possible

  8. Tree-Ring Investigation of an in situ Younger Dryas-Age Spruce Forest in the Great Lakes Region of N. America (United States)

    Panyushkina, I. P.; Leavitt, S. W.; Lange, T.; Schneider, A. F.


    A late Pleistocene-early Holocene geological site known as Liverpool East on the southern end of Lake Michigan (in Indiana) was discovered in the early 1980s. Five previously reported radiocarbon dates on wood and peat from the deposit ranged from 9,080 to 11,290 14C yr B.P., but our subsequent radiocarbon dating of wood from in situ spruce stumps at the site has yielded four ages from 10,060 to 10,444 14C yr B.P., which correspond to calibrated calendar ages between about 11,550 and 12,500 Cal yr B.P. These dates place this forest squarely into the Younger Dryas event, and offer an unusual opportunity for exploring high-resolution environmental variability during an abrupt climate change event related to ocean thermohaline circulation. In the last 3 years, we have collected more than 130 pieces of wood from the site, about 65 of which are from stumps. Typical separation of trees was about 2-3 m, suggesting more of an open woodland than dense forest. The tilting of many stumps suggests the effect of wind on trees rooted in a soft peat substrate, and their tops broken at uniform height seem consistent with a subsequent rise in lake level, beach sand deposition, and ice floe event(s) that sheared off the upper trunks. Although these trees tend to be fairly young (typically 50-100 years old) and somewhat complacent, we developed a ring-width chronology to examine interannual variability. We are also measuring stable-oxygen and stable-carbon isotope ratios on α-cellulose in sequences of individual rings for several trees as additional environmental indicators of moisture and temperature. This collective set of tree-ring measurements and their statistics provide the basis for inferring the environment of this site, placed more precisely in time by "wiggle-matching" a sequence of 10-year radiocarbon measurements.

  9. Impacts of site effects on losses of oriental spruce during ...

    African Journals Online (AJOL)



    Aug 18, 2009 ... developed for oriental spruce and depends on the relation of stand mean diameter and number of trees in a hectare. Wood loss determination. The volume of the damaged, infested and cut trees because of the beetle damage was calculated in 158 experimental plots in 4.74 ha area in spruce forests.

  10. Forests and Open Woodlands of Alpine-Taiga Landscapes of the Bureya Mountains (Diversity, Structure, and Dynamics

    Directory of Open Access Journals (Sweden)

    S. V. Osipov


    Full Text Available Many of classic questions of vegetation and forest sciences do not lose their relevance because they are basic knowledge for solving a large number of scientific and practical tasks. The aims of this paper are to describe the coenotic diversity, structure, catastrophic and successional changes of forests and open woodlands in alpine-taiga landscapes of the Bureya Mountains, and to consider some of the approaches that are promising for solving such problems. The analysis of some important characteristics of forest and open woodland vegetation is executed. It is shown that the peculiarities of woodland vegetation are not always reflected in the classification schemes. Contrasting approaches to the classification of woodland vegetation are considered. The main diversity of forest and woodland communities, micro-, meso - and macrocomplexes of alpine-taiga landscapes of the Bureya Mountains is revealed. The main forest forming species of trees are the Ajan spruce (Picea ajanensis and Cajander larch (Larix cajanderi. The ecological-phytocoenological classification of forest and woodland vegetation is developed. A concept of the life form of vegetation is used as a common basis for the classification of vegetation of different structural types. The concept is considered as the multidimensional and multilevel characteristic of vegetation, which consists of at least three components: structural, dynamic and ecological-phytocoenotic types of vegetation. The scheme of vegetation cover zonality of alpine-taiga landscapes of the Bureya Mountains is revised on the basis of concepts of the zonal vegetation and the zonal habitats. Forest and open woodland vegetation form three subbelts: subalpine larch and spruce open woodlands, subalpine spruce and larch forests, taiga spruce and larch forests. The main disturbance factor in vegetation cover of the territory under consideration is fires. Main pyrogenic catastrophic changes and post-fire demutation successions

  11. Modeling the effects of fire severity and climate warming on active layer and soil carbon dynamics of black spruce forests across the landscape in interior Alaska (United States)

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


    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

  12. Fire Severity Controlled Susceptibility to a 1940s Spruce Beetle Outbreak in Colorado, USA.

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    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

  13. Nutrient imbalance in Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar


    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. Early lessons from commercial thinning in a 30-year-old Sitka Spruce-Western Hemlock forest. (United States)

    Sarah E. Greene; William H. Emmingham


    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...

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

    Mark P. Waldrop; Jennifer W. Harden


    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. 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


    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

  17. Variation in carbohydrate source-sink relations of forest and treeline white spruce in southern, interior and northern Alaska (United States)

    Bjartmar Sveinbjornsson; Matthew Smith; Tumi Traustason; Roger W. Ruess; Patrick F. Sullivan


    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,...

  18. Evidence of compounded disturbance effects on vegetation recovery following high-severity wildfire and spruce beetle outbreak (United States)

    Carlson, Amanda R.; Sibold, Jason S.; Assal, Timothy J.; Negrón, José F.


    Spruce beetle (Dendroctonus rufipennis) outbreaks are rapidly spreading throughout subalpine forests of the Rocky Mountains, raising concerns that altered fuel structures may increase the ecological severity of wildfires. Although many recent studies have found no conclusive link between beetle outbreaks and increased fire size or canopy mortality, few studies have addressed whether these combined disturbances produce compounded effects on short-term vegetation recovery. We tested for an effect of spruce beetle outbreak severity on vegetation recovery in the West Fork Complex fire in southwestern Colorado, USA, where much of the burn area had been affected by severe spruce beetle outbreaks in the decade prior to the fire. Vegetation recovery was assessed using the Landsat-derived Normalized Difference Vegetation Index (NDVI) two years after the fire, which occurred in 2013. Beetle outbreak severity, defined as the basal area of beetle-killed trees within Landsat pixels, was estimated using vegetation index differences (dVIs) derived from pre-outbreak and post-outbreak Landsat images. Of the seven dVIs tested, the change in Normalized Difference Moisture Index (dNDMI) was most strongly correlated with field measurements of beetle-killed basal area (R2 = 0.66). dNDMI was included as an explanatory variable in sequential autoregressive (SAR) models of NDVI2015. Models also included pre-disturbance NDVI, topography, and weather conditions at the time of burning as covariates. SAR results showed a significant correlation between NDVI2015 and dNDMI, with more severe spruce beetle outbreaks corresponding to reduced post-fire vegetation cover. The correlation was stronger for models which were limited to locations in the red stage of outbreak (outbreak ≤ 5 years old at the time of fire) than for models of gray-stage locations (outbreak > 5 years old at the time of fire). These results indicate that vegetation recovery processes may be negatively impacted by severe

  19. Evidence of compounded disturbance effects on vegetation recovery following high-severity wildfire and spruce beetle outbreak.

    Directory of Open Access Journals (Sweden)

    Amanda R Carlson

    Full Text Available Spruce beetle (Dendroctonus rufipennis outbreaks are rapidly spreading throughout subalpine forests of the Rocky Mountains, raising concerns that altered fuel structures may increase the ecological severity of wildfires. Although many recent studies have found no conclusive link between beetle outbreaks and increased fire size or canopy mortality, few studies have addressed whether these combined disturbances produce compounded effects on short-term vegetation recovery. We tested for an effect of spruce beetle outbreak severity on vegetation recovery in the West Fork Complex fire in southwestern Colorado, USA, where much of the burn area had been affected by severe spruce beetle outbreaks in the decade prior to the fire. Vegetation recovery was assessed using the Landsat-derived Normalized Difference Vegetation Index (NDVI two years after the fire, which occurred in 2013. Beetle outbreak severity, defined as the basal area of beetle-killed trees within Landsat pixels, was estimated using vegetation index differences (dVIs derived from pre-outbreak and post-outbreak Landsat images. Of the seven dVIs tested, the change in Normalized Difference Moisture Index (dNDMI was most strongly correlated with field measurements of beetle-killed basal area (R2 = 0.66. dNDMI was included as an explanatory variable in sequential autoregressive (SAR models of NDVI2015. Models also included pre-disturbance NDVI, topography, and weather conditions at the time of burning as covariates. SAR results showed a significant correlation between NDVI2015 and dNDMI, with more severe spruce beetle outbreaks corresponding to reduced post-fire vegetation cover. The correlation was stronger for models which were limited to locations in the red stage of outbreak (outbreak ≤ 5 years old at the time of fire than for models of gray-stage locations (outbreak > 5 years old at the time of fire. These results indicate that vegetation recovery processes may be negatively impacted by

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

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


    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. Effect of dominant ground vegetation on soil organic matter quality in a declining mountain spruce forest of central Europe

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, E.; Santoni, S.; Zanini, E. (Universita degli Studi di Torino (Italy)); Cudlin, P. (Inst. of Systems Biology and Ecology, Czech Academy of Sciences (Czech Republic))


    Grasses and shrubs constitute a high proportion of the total biomass in declining forest stands and may deeply affect soil organic matter. We fractionated the organic matter of 45 Oa horizons from the Krkonose Mts. into humic and fulvic acids (HA and FA) and related the differences to the dominant ground vegetation Vaccinium myrtillus, Deschampsia flexuosa and Molinia caerulea. Organic C was higher under M. caerulea than under Vaccinium myrtillus, but the humification rate was similar at all sites. A higher proportion of HA was found under M. caerulea, indicating that differences in species lead to variations in the quality of humic substances, but not in the quantitative aspects of the humification process. Regarding the importance of HA and FA in soil development, the findings suggest that, upon forest decline, major changes may be expected not only in the O horizons, but also in the whole soil profile. (orig.)

  2. Animal vectors of eastern dwarf mistletoe of black spruce. (United States)

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


    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.

  3. Fire, fuel composition and resilience threshold in subalpine ecosystem.

    Directory of Open Access Journals (Sweden)

    Olivier Blarquez

    Full Text Available BACKGROUND: Forecasting the effects of global changes on high altitude ecosystems requires an understanding of the long-term relationships between biota and forcing factors to identify resilience thresholds. Fire is a crucial forcing factor: both fuel build-up from land-abandonment in European mountains, and more droughts linked to global warming are likely to increase fire risks. METHODS: To assess the vegetation response to fire on a millennium time-scale, we analyzed evidence of stand-to-local vegetation dynamics derived from sedimentary plant macroremains from two subalpine lakes. Paleobotanical reconstructions at high temporal resolution, together with a fire frequency reconstruction inferred from sedimentary charcoal, were analyzed by Superposed Epoch Analysis to model plant behavior before, during and after fire events. PRINCIPAL FINDINGS: We show that fuel build-up from arolla pine (Pinus cembra always precedes fires, which is immediately followed by a rapid increase of birch (Betula sp., then by ericaceous species after 25-75 years, and by herbs after 50-100 years. European larch (Larix decidua, which is the natural co-dominant species of subalpine forests with Pinus cembra, is not sensitive to fire, while the abundance of Pinus cembra is altered within a 150-year period after fires. A long-term trend in vegetation dynamics is apparent, wherein species that abound later in succession are the functional drivers, loading the environment with fuel for fires. This system can only be functional if fires are mainly driven by external factors (e.g. climate, with the mean interval between fires being longer than the minimum time required to reach the late successional stage, here 150 years. CONCLUSION: Current global warming conditions which increase drought occurrences, combined with the abandonment of land in European mountain areas, creates ideal ecological conditions for the ignition and the spread of fire. A fire return interval of less

  4. Population dynamics and bioenergetics of a fossorial herbivore, Thomomys talpoides (Rodentia: Geomyidae), in a spruce-fir sere (United States)

    Andersen, Douglas C.; MacMahon, James A.


    Studies of the bioenergetics of the northern pocket gopher, Thomomys talpoides, are coupled with data on demography, activity budgets, and microclimates to model the energy requirements of individuals and populations in the Wasatch Mountains of Utah during 1976-1979. Metabolic rates during rest increased linearly with decreasing ambient temperature, but burrowing metabolic rates (16.3 mL O2 • h-1 • g-9.75) were independent of both temperature and physical properties of the soil. Radio-telemetry studies indicated that free-ranging gophers are active =50% of each day. Conservative estimates of true energy consumption were calculated using estimates of habitat-specific minimum daily burrowing requirements. Rates of burrowing measured in the laboratory were either ∞ 0.0 or ∞ 2.0 cm/min. The low burrowing rate was observed when the soil was frozen or saturated with water, as would occur in the field in early winter and in spring, respectively. Gophers burrowed through soil at the study site at an average rate of ∞ 1.5 cm/min. Belowground food energy densities at gopher foraging depth declined from 24.6 to 3.2 J/cm3 along a successional gradient (subalpine forb meadow to Engelmann spruce dominated forest). We conclude that individual gophers are food limited within the climax spruce seral stage. Further, daily energy costs associated with reproduction in females may exceed the belowground energy supply available in intermediate seral stages (aspen and subalpine fir). Reduction of burrowing rates for any reason will affect gophers in the late seral stages proportionately more than those resident in the meadow. The peak gopher densities recorded (from 62 individuals/ha in the meadow to 2 individuals/ha in spruce forest) support these inferences. Detailed demographic information was obtained only in the meadow seral stage. Adult survivorship was lower in winter than in summer and varied greatly between years (0.18-0.70 yr-1). Juvenile survivorship from weaning


    Directory of Open Access Journals (Sweden)

    Ali Ömer Üçler


    Full Text Available In this study, naturally regenerated succesfull oriental spruce (Picea orientalis (L. Link and fir (Abies nordmanniana Spach. subsp. nordmanniana mixed stand which encompass 5.8 ha area was examined. For that, seedlings in the area were studied for their relationship between growth and age. In addition, the amount of seedlings reached to area after the cuttings with large shelterwood system were determined. The age and height of fir and oriental spruce seedlings in 24 sampling areas each covering 25 square meters are measured according to square method and sampling areas systematically distributed so that samples could represent the regeneration area. Evaluating gathered data, seedlings reached to the area orderly after 1975 preperation cutting. Measurements and counts showed that orieantal spruce hold rich seeds every 4 years, however, this differentiation is not evident for fir. Evaluating height growth depending on age, correlation coefficients are found 0.9993 for oriental spruce and 0.9973 for fir, therefore the seedlings of fir and oriental spruce realized similar growth during their regeneration stage

  6. Sensitivity of subalpine tree seedlings and alpine plants to natural and manipulated climate variation: Initial results from an Alpine Treeline Warming Experiment (Invited) (United States)

    Kueppers, L. M.


    Niche models and paleoecological studies indicate that future climate change will alter the geographic distributions of plant species. Changes in temperature, snowmelt timing, or moisture conditions at one edge of a species’ range may have different consequences for recruitment, carbon exchange, phenology, and survival than changes at another edge. Similarly, local genetic adaptation may constrain species and community responses to climate change. We have established a new experiment to investigate potential shifts in the distribution of subalpine tree species, and the alpine species they might replace. We are asking how tree species recruitment and alpine species growth and reproduction vary within their current ranges, and in response to temperature and soil moisture manipulations. We are also examining whether genetic provenance and ecosystem processes constrain tree seedling and alpine herb responses. Our Alpine Treeline Warming Experiment is located across three sites at Niwot Ridge, CO, ranging from near the lower limit of subalpine forest to alpine tundra. We use infrared heaters to raise growing season surface soil temperatures by 4-5°C, and to lengthen the growing season. The warming treatment is crossed with a soil moisture manipulation to distinguish effects due to higher temperatures from those due to drier soil. Each plot is a common garden sown with high and low elevation provenances of limber pine (Pinus flexilis) and Engelmann spruce (Picea engelmannii). We established an additional set of experimental plots to examine treatment effects on alpine species phenology, growth and reproduction. Under ambient conditions in 2009, tree seedling germination rate, lifespan, and first season survival was higher within the species’ current range than in the alpine, and for Engelmann spruce, was higher at the low elevation limit than the high elevation limit. Source population (low vs. high elevation) was a significant factor explaining natural variation in

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

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    K. Butterbach-Bahl


    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

  8. Changes in downed and dead woody material following a spruce beetle outbreak on the Kenai Peninsula, Alaska. (United States)

    Bethany. Schulz


    The forests of the Kenai Peninsula, Alaska, underwent a major spruce beetle(Dendroctonus rufipennis (Kirby)) outbreak in the 1990s. A repeated inventory of forest resources was designed to assess the effects of the resulting widespread mortality of spruce trees, the dominant component of the Kenai forests. Downed woody materials, fuel heights, and...

  9. The Effect of Re-Planting Trees on Soil Microbial Communities in a Wildfire-Induced Subalpine Grassland

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    Ed-Haun Chang


    Full Text Available Wildfire often causes tremendous changes in ecosystems, particularly in subalpine and alpine areas, which are vulnerable due to severe climate conditions such as cold temperature and strong wind. This study aimed to clarify the effect of tree re-planting on ecosystem services such as the soil microbial community after several decades. We compared the re-planted forest and grassland with the mature forest as a reference in terms of soil microbial biomass C and N (Cmic and Nmic, enzyme activities, phospholipid fatty acids (PLFA composition, and denaturing gradient gel electrophoresis (DGGE. The Cmic and Nmic did not differ among the grassland, re-planted forest and mature forest soil; however, ratios of Cmic/Corg and Nmic/Ntot decreased from the grassland to re-planted forest and mature forest soil. The total PLFAs and those attributed to bacteria and Gram-positive and Gram-negative bacteria did not differ between the re-planted forest and grassland soil. Principle component analysis of the PLFA content separated the grassland from re-planted forest and mature forest soil. Similarly, DGGE analysis revealed changes in both bacterial and fungal community structures with changes in vegetation. Our results suggest that the microbial community structure changes with the re-planting of trees after a fire event in this subalpine area. Recovery of the soil microbial community to the original state in a fire-damaged site in a subalpine area may require decades, even under a re-planted forest.

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

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

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


    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...

  12. Calcium addition at the Hubbard Brook Experimental Forest increases sugar storage, antioxidant activity and cold tolerance in native red spruce (Picea rubens) (United States)

    Joshua M. Halman; Paul G. Schaberg; Gary J. Hawley; Christopher Eagar


    In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO3, a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition...

  13. 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


    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

  14. Can spruce beetle (Dendroctonus rufipennis Kirky) pheromone trap catches or stand conditions predict Engelmann spruce (Picea engelmannii Parry ex Engelm.) tree mortality in Colorado? (United States)

    Jose F. Negron; John B. Popp


    1) Bark beetles (Coleoptera: Curculionidae: Scolytinae) can cause extensive tree mortality in forests dominated by their hosts. Among these, the spruce beetle (Dendroctonus rufipennis) is one of the most important beetles in western North America causing Engelmann spruce (Picea engelmannii) tree mortality. 2) Although pheromone traps with attractants are commonly used...

  15. Role of Nurse Logs in Forest Expansion at Timberline (United States)

    Johnson, A. C.; Yeakley, A.


    Nurselogs, known to be key sites of forest regeneration in lower elevation temperate forests, may be important sites for seedling establishment at expanding timberline forests. To determine factors associated with seedling establishment and survival on nurselogs at timberline, fourteen sites, located across a precipitation gradient in the Washington North Cascades Mountains, were examined. Site attributes including seedling type and height, disturbance process introducing downed wood, wood decay type, shading, slope gradient, aspect, and temperature and water content of wood and adjacent soil were determined along 60 m long transects. Nurselogs were found at 13 out of 14 sites; sites typically associated with greater than 80% shade and downed wood having a high level of wood decay. Downed wood serving as nurselogs originated from blowdown, snow avalanches, and forest fires. In total, 46 of 136 downed wood pieces observed served as nurselogs. Seedlings on nurselogs included mountain hemlock (Tsuga mertensiana), Pacific silver fir (Abies amabilis), yellow cedar (Chamaecyparis nootkatensis), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and western larch (Larix occidentalis). Nurselogs had significantly higher temperatures (p = 0.015) and higher moisture contents (p = 0.019) than the adjacent soil. Per equal volumes weighed, nurselogs had on average of 23.8 g more water than the adjacent soil. Given predictions of climate warming and associated summer drought conditions in Pacific Northwest forests, the moisture provided by nurselogs may be integral for conifer survival and subsequent timberline expansion in some landscapes.

  16. Effect of wildfire and fireline construction on the annual depth of thaw in a black spruce permafrost forest in interior Alaska: a 36-year record of recovery (United States)

    Leslie A. Viereck; Nancy R. Werdin-Pfisterer; Phyllis C. Adams; Kenji Yoshikawa


    Maximum thaw depths were measured annually in an unburned stand, a heavily burned stand, and a fireline in and adjacent to the 1971 Wickersham fire. Maximum thaw in the unburned black spruce stand ranged from 36 to 52 cm. In the burned stand, thaw increased each year to a maximum depth of 302 cm in 1995. In 1996, the entire layer of seasonal frost remained, creating a...

  17. Eddy covariance fluxes of the NO-NO2-O3 triad above a spruce forest canopy in south-eastern Germany. (United States)

    Tsokankunku, A.; Zhu, Z.; Meixner, F. X.; Foken, T.; Andreae, M. O.


    We investigated the diel variability of the eddy covariance fluxes of the NO-NO2-O3 triad above a spruce forest canopy at the "Weidenbrunnen" research site (Fichtelgebirge, Germany). Measurements were part of the EGER project (ExchanGE processes in mountainous Regions), which focuses on the role of process interactions among the different scales of soil, in-canopy and atmospheric exchange processes of reactive and non-reactive trace gases and energy. The eddy covariance platform was at the top of a 32 m high tower (50˚ 08'31" N, 11˚ 52'1"E, elevation 755 m.a.s.l). The eddy covariance system consisted of a CSAT3 sonic anemometer and a high speed, high resolution NO-NO2two channel chemiluminescence analyzer (Ecophysics CLD 790 SR2). A solid-state blue-light photolytic converter was connected to the NO2 channel of the analyzer just behind the sample inlet. Ambient NO and NO2 mixing ratios were sampled via 52 m long tubes with the instrument itself located in a temperature-controlled container at the ground. The NO-NO2 analyzer was operated at 5 Hz. Additionally we measured eddy covariance fluxes of CO2 and H2O. An infrared absorption-based analyzer (LI-7000) was used to sample CO2 and H2O mixing ratios, and a fast solid-phase chemiluminescence ozone analyzer (GFAS) was deployed to measure O3 mixing ratios. All trace gas inlets were situated at 32.5 m, 20 cm below the path of the sonic anemometer. The 32m inlet of an independent NO, NO2, and O3 concentration profile measuring system was used as the calibration source for the fast ozone analyzer and the two channel NO-NO2chemiluminescence analyzer. Preliminary results show that NO and NO2advection plays a big role in the magnitude and direction of the fluxes at the site. The main source of the advection is a busy country road situated about 2 km west of the site. CO2 fluxes were also influenced by advection. Extended periods of stationarity usually occurred on Sundays when the amount of traffic was significantly

  18. The western spruce budworm model: structure and content. (United States)

    K.A. Sheehan; W.P. Kemp; J.J. Colbert; N.L. Crookston


    The Budworm Model predicts the amounts of foliage destroyed annually by the western spruce budworm, Choristoneura occidentalis Freeman, in a forest stand. The model may be used independently, or it may be linked to the Stand Prognosis Model to simulate the dynamics of forest stands. Many processes that affect budworm population dynamics are...

  19. Physiological and environmental causes of freezing injury in red spruce (United States)

    Paul G. Schaberg; Donald H. DeHayes


    For many, concerns about the implications of "environmental change" conjure up scenarios of forest responses to global warming, enrichment of greenhouse gases, such as carbon dioxide and methane, and the northward migration of maladapted forests. From that perspective, the primary focus of this chapter, that is, causes of freezing injury to red spruce (

  20. Temporal dynamics of abiotic and biotic factors on leaf litter of three plant species in relation to decomposition rate along a subalpine elevation gradient.

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    Jianxiao Zhu

    Full Text Available Relationships between abiotic (soil temperature and number of freeze-thaw cycles or biotic factors (chemical elements, microbial biomass, extracellular enzymes, and decomposer communities in litter and litter decomposition rates were investigated over two years in subalpine forests close to the Qinghai-Tibet Plateau in China. Litterbags with senescent birch, fir, and spruce leaves were placed on the forest floor at 2,704 m, 3,023 m, 3,298 m, and 3,582 m elevation. Results showed that the decomposition rate positively correlated with soil mean temperature during the plant growing season, and with the number of soil freeze-thaw cycles during the winter. Concentrations of soluble nitrogen (N, phosphorus (P and potassium (K had positive effects but C:N and lignin:N ratios had negative effects on the decomposition rate (k, especially during the winter. Meanwhile, microbial biomass carbon (MBC, N (MBN, and P (MBP were positively correlated with k values during the first growing season. These biotic factors accounted for 60.0% and 56.4% of the variation in decomposition rate during the winter and the growing season in the first year, respectively. Specifically, litter chemistry (C, N, P, K, lignin, C:N and lignin:N ratio independently explained 29.6% and 13.3%, and the microbe-related factors (MBC, MBN, MBP, bacterial and fungal biomass, sucrase and ACP activity explained 22.9% and 34.9% during the first winter and the first growing season, respectively. We conclude that frequent freeze-thaw cycles and litter chemical properties determine the winter decomposition while microbe-related factors play more important roles in determining decomposition in the subsequent growing season.

  1. Manipulation of subalpine and alpine microclimate in the Alpine Treeline Warming Experiment (United States)

    Kueppers, L. M.; Moyes, A. B.; Ferrenberg, S. M.; Christianson, D. S.; Castanha, C.; Germino, M. J.


    To experimentally test model projections of subalpine tree species' uphill migration with climate change, we have established the Alpine Treeline Warming Experiment at Niwot Ridge, CO. Common gardens subject to full factorial warming and watering experiments are replicated across three sites: near the lower limit of subalpine forest, within the alpine-treeline ecotone, and in the alpine tundra, beyond the current elevation ranges of the species. In 2010, differences in ambient climate among the three sites included 5.1° C greater growing-season air temperature and 0.5 kPa greater vapor pressure deficit in the lowest compared to the upper two sites. The lower subalpine site also experienced lower soil moisture compared to the upper two sites. Snowmelt date varied substantially between sites, with the longest snow-free period in the lower subalpine site and the shortest in the treeline site. In all sites, we observed advances in the timing of snowmelt in heated relative to control plots. The warming treatment also raised 5 cm soil temperatures by 3° C at the lower subalpine site, and by 1° C in the upper two sites, averaged over the growing season. More substantial wind in the alpine diminished the heating effect through sensible heat loss. Seasonal average volumetric soil moisture at 5-10 cm did not vary strongly among treatments even though seedling survival and gas exchange data suggest that water additions alleviated drought stress in some plots. These preliminary findings for identical warming and watering treatments across our three high mountain sites suggest that microclimate responses vary with radiation environment, patterns of snow accumulation, and wind speed. Some of these differences are realistic for a future warmer world, while others are artifacts of the experimental approach. Microclimate differences in 2011 reflect modified heating methods and a different spring hydroclimate (later snow accumulation and melt), highlighting the importance of

  2. South-central Alaska forests: inventory highlights. (United States)

    Sally Campbell; Willem W.S. van Hees; Bert. Mead


    This publication presents highlights of a recent south-central Alaska inventory conducted by the Pacific Northwest Research Station Forest Inventory and Analysis Program (USDA Forest Service). South-central Alaska has about 18.5 million acres, of which one-fifth (4 million acres) is forested. Species diversity is greatest in closed and open Sitka spruce forests, spruce...

  3. The Effect of Re-Planting Trees on Soil Microbial Communities in a Wildfire-Induced Subalpine Grassland


    Ed-Haun Chang; Guanglong Tian; Chih-Yu Chiu


    Wildfire often causes tremendous changes in ecosystems, particularly in subalpine and alpine areas, which are vulnerable due to severe climate conditions such as cold temperature and strong wind. This study aimed to clarify the effect of tree re-planting on ecosystem services such as the soil microbial community after several decades. We compared the re-planted forest and grassland with the mature forest as a reference in terms of soil microbial biomass C and N (Cmic and Nmic), enzyme activit...

  4. Acidic deposition, cation mobilization, and biochemical indicators of stress in healthy red spruce (United States)

    Walter C. Shortle; Kevin T. Smith; Rakesh Minocha; Gregory B. Lawrence; Mark B. David


    Dendrochemical and biochemical markers link stress in apparently healthy red spruce trees (Picea rubens) to acidic deposition. Acidic deposition to spruce forests of the northeastern USA increased sharply during the 1960s. Previous reports related visible damage of trees at high elevations to root and soil processes. In this report, dendrochemical...

  5. A density management diagram for Norway spruce in the temperate Europe montane region (United States)

    Giorgio Vacchiano; R. Justin DeRose; John D. Shaw; Miroslav Svoboda; Renzo Motta


    Norway spruce is one of the most important conifer tree species in Europe, paramount for timber provision, habitat, recreation, and protection of mountain roads and settlements from natural hazards. Although natural Norway spruce forests exhibit diverse structures, even-aged stands can arise after disturbance or as the result of common silvicultural practice, including...

  6. Climate changes and wildfire alter vegetation of Yellowstone National Park, but forest cover persists (United States)

    Clark, Jason A.; Loehman, Rachel A.; Keane, Robert E.


    We present landscape simulation results contrasting effects of changing climates on forest vegetation and fire regimes in Yellowstone National Park, USA, by mid-21st century. We simulated potential changes to fire dynamics and forest characteristics under three future climate projections representing a range of potential future conditions using the FireBGCv2 model. Under the future climate scenarios with moderate warming (>2°C) and moderate increases in precipitation (3–5%), model simulations resulted in 1.2–4.2 times more burned area, decreases in forest cover (10–44%), and reductions in basal area (14–60%). In these same scenarios, lodgepole pine (Pinus contorta) decreased in basal area (18–41%), while Douglas-fir (Pseudotsuga menziesii) basal area increased (21–58%). Conversely, mild warming (<2°C) coupled with greater increases in precipitation (12–13%) suggested an increase in forest cover and basal area by mid-century, with spruce and subalpine fir increasing in abundance. Overall, we found changes in forest tree species compositions were caused by the climate-mediated changes in fire regime (56–315% increase in annual area burned). Simulated changes in forest composition and fire regime under warming climates portray a landscape that shifts from lodgepole pine to Douglas-fir caused by the interaction between the magnitude and seasonality of future climate changes, by climate-induced changes in the frequency and intensity of wildfires, and by tree species response.

  7. Eight years of integrated monitoring in Alpine forest ecosystems of Trentino and South Tyrol, Italy

    Directory of Open Access Journals (Sweden)



    Full Text Available After the acute emergency of decline in European woodland at the beginning of 1980’s, forest health was the subject of several studies in Trentino and South-Tyrol. Since 1992 investigations focused on an integrated monitoring under the UN-ECE-ICP programme in 4 selected areas, 2 in subalpine Norway spruce woodland (Lavazè Pass and Renon, and 2 in thermophilous Pubescent oak woodland (Pomarolo and Monticolo. The interdisciplinary programme of integrated monitoring aimed to investigate the state of alpine semi-natural forests in relation to air pollution, anthropogenic stresses, climate changes and trophic-energetic balances. Assessment of forest health by means of crown conditions showed very low levels of defoliation and discoloration in the subalpine areas, while in the other ones the same parameters had slightly higher values. Every year and in all the sites the mean percentages values were always in class 0 and class 1, hence indicating no danger. Weather patterns showed the presence of occasional water deficit, albeit general trends were not observed. High level of pollution were never detected while the level of acidity in rainfall has been slightly decreasing in all the investigated plots. Only ozone showed higher values than normal but there was no correlation with any damage. Foliar mineral nutrient contents ranged quite always within the threshold level. Because of the few years of observation and the absence of relevant stress, it is not possible to get any indication about the relationship between the forest health status and the fungi community composition. The presence of some anomalous data and the growing concern on climate change give reason to the importance of a continuous monitoring action acquiring of comparable set of data, in order to get a better understanding of forest ecosystems response to stress and make progress in general ecological knowledge.

  8. Two-dimensional wavelet analysis of spruce budworm host basal area in the Border Lakes landscape (United States)

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


    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....

  9. Ecology of beech regeneration in the allochthonous spruce stands – a case study

    Directory of Open Access Journals (Sweden)

    Lumír Dobrovolný


    Full Text Available We study the successional process of beech in a allochthonous spruce monocultures. In the natural regeneration of the predominatly spruce stand (area: 14.28 ha, age: 110 years with single mother beech trees admixture the spruce regeneration occupies the most part of the study area. However, about one quarter of area is occupied relatively regular by beech regeneration. The spruce density was at all times higher than that of beech while the spruce height grow was by contrast at all times lower than that of beech. Mean distance of beech seedlings dispersion is 12.7; at a distance greater than 40 m, the density already neared zero. Density of spruce increases with increasing light intensity, the density of beech decreases – the competition point was found about 19% of diffuse radiation or about 14% of canopy openness. The both species respond to increase of light intensity with increase of height grow (by beech only weekly – the spruce starts to dominate the beech at about 32% of diffuse radiation or about 22% of canopy openness. The silvicultural goal in the next stand generation – converting of spruce forest into mixed forest, i.e. achievement of the legal proportion of beech as a soil-improving and reinforcing tree species (proportion about 30% and more in the spruce stand can be reliably realized by natural way only using a combination of more intensive shelterwood or border felling with group selection system.

  10. Dispersal of forest insects (United States)

    Mcmanus, M. L.


    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.

  11. Assessment of spruce (Picea obovata) abundance by spectral unmixing algorithm for sustainable forest management in highland Natural Reserve (case study of Zigalga Range, South-Ural State Natural Reserve, Russia). (United States)

    Mikheeva, Anna; Moiseev, Pavel


    Zigalga Range and were visited in summer 2016. We used Mixture-tuned Match Filtering (MTMF) algorithm, a non-linear subpixel classification technique which allows to separate the spectral mixture containing unknown objects, and to derive only known ones. The results of spectral unmixing classification were abundance maps of Picea obovata. The values were statistically determined (there was only selected abundances with high probabilities of presence and low probabilities of absence) and then constrained to the interval [0; 1]. Verification of maps was made at the sites of Iremel Mountains on the same ASTER image, where projective cover of Picea obovata was measured in the field in 147 points. The correlation coefficient between the spectral unmixing abundances and field-measured abundances was 0.7; not a very high value is due to the low sensitivity of the algorithm to detect abundances less than 0.25. The proposed method provides a tool for defining the Picea obovata boundaries more accurately than per-pixel automatic classification and locating new spruce islands in the mixing tree line environment. The abundances can be obtained for large areas with minimum field work which makes this approach cost-effective in providing timely information to nature reserve managers for adapting forest management actions to climate change.

  12. Ecosystem CO2/H2O fluxes are explained by hydraulically limited gas exchange during tree mortality from spruce bark beetles (United States)

    Frank, John M.; Massman, William J.; Ewers, Brent E.; Huckaby, Laurie S.; Negrón, José F.


    Disturbances are increasing globally due to anthropogenic changes in land use and climate. This study determines whether a disturbance that affects the physiology of individual trees can be used to predict the response of the ecosystem by weighing two competing hypothesis at annual time scales: (a) changes in ecosystem fluxes are proportional to observable patterns of mortality or (b) to explain ecosystem fluxes the physiology of dying trees must also be incorporated. We evaluate these hypotheses by analyzing 6 years of eddy covariance flux data collected throughout the progression of a spruce beetle (Dendroctonus rufipennis) epidemic in a Wyoming Engelmann spruce (Picea engelmannii)-subalpine fir (Abies lasiocarpa) forest and testing for changes in canopy conductance (gc), evapotranspiration (ET), and net ecosystem exchange (NEE) of CO2. We predict from these hypotheses that (a) gc, ET, and NEE all diminish (decrease in absolute magnitude) as trees die or (b) that (1) gc and ET decline as trees are attacked (hydraulic failure from beetle-associated blue-stain fungi) and (2) NEE diminishes both as trees are attacked (restricted gas exchange) and when they die. Ecosystem fluxes declined as the outbreak progressed and the epidemic was best described as two phases: (I) hydraulic failure caused restricted gc, ET (28 ± 4% decline, Bayesian posterior mean ± standard deviation), and gas exchange (NEE diminished 13 ± 6%) and (II) trees died (NEE diminished 51 ± 3% with minimal further change in ET to 36 ± 4%). These results support hypothesis b and suggest that model predictions of ecosystem fluxes following massive disturbances must be modified to account for changes in tree physiological controls and not simply observed mortality.

  13. 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


    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

  14. SPRUCE Mashup London

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    Edward M. Corrado


    Full Text Available SPRUCE digital preservation mashups are a series of unique events that are being organized in the United Kingdom to bring together digital preservation practitioners and developers to work on real-world digital preservation challenges. During the 3-day event the digital preservation developers work to create practical solutions to real-world challenges the practitioners are having related to digital preservation. Meanwhile, the practitioners work to create compelling business cases for digital preservation at their institution. This article describes the SPRUCE Mashup London event held in September 2012.

  15. Biogeochemical impacts of wildfires over four millennia in a Rocky Mountain subalpine watershed. (United States)

    Dunnette, Paul V; Higuera, Philip E; McLauchlan, Kendra K; Derr, Kelly M; Briles, Christy E; Keefe, Margaret H


    Wildfires can significantly alter forest carbon (C) storage and nitrogen (N) availability, but the long-term biogeochemical legacy of wildfires is poorly understood. We obtained a lake-sediment record of fire and biogeochemistry from a subalpine forest in Colorado, USA, to examine the nature, magnitude, and duration of decadal-scale, fire-induced ecosystem change over the past c. 4250 yr. The high-resolution record contained 34 fires, including 13 high-severity events within the watershed. High-severity fires were followed by increased sedimentary N stable isotope ratios (δ15N) and bulk density, and decreased C and N concentrations--reflecting forest floor destruction, terrestrial C and N losses, and erosion. Sustained low sediment C : N c. 20-50 yr post-fire indicates reduced terrestrial organic matter subsidies to the lake. Low sedimentary δ15N c. 50-70 yr post-fire, coincident with C and N recovery, suggests diminishing terrestrial N availability during stand development. The magnitude of post-fire changes generally scaled directly with inferred fire severity. Our results support modern studies of forest successional C and N accumulation and indicate pronounced, long-lasting biogeochemical impacts of wildfires in subalpine forests. However, even repeated high-severity fires over millennia probably did not deplete C or N stocks, because centuries between high-severity fires allowed for sufficient biomass recovery. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  16. Identifying calcium sources at an acid deposition-impacted spruce forest: a strontium isotope, alkaline earth element multi-tracer approach (United States)

    Thomas D. Bullen; Scott W. Bailey


    Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources. but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium isotope and alkaline earth element concentration...

  17. Diapause and overwintering of two spruce bark beetle species. (United States)

    Schebeck, Martin; Hansen, E Matthew; Schopf, Axel; Ragland, Gregory J; Stauffer, Christian; Bentz, Barbara J


    Diapause, a strategy to endure unfavourable conditions (e.g. cold winters) is commonly found in ectothermic organisms and is characterized by an arrest of development and reproduction, a reduction of metabolic rate, and an increased resistance to adversity. Diapause, in addition to adaptations for surviving low winter temperatures, significantly influences phenology, voltinism and ultimately population growth. We review the literature on diapause and overwintering behaviour of two bark beetle species that affect spruce-dominated forests in the northern hemisphere, and describe and compare how these strategies can influence population dynamics. The European spruce bark beetle Ips typographus (L.) (Coleoptera, Curculionidae) is the most important forest pest of Norway spruce in Europe. It enters an adult reproductive diapause that might be either facultative or obligate. Obligate diapausing beetles are considered strictly univoltine, entering this dormancy type regardless of environmental cues. Facultative diapausing individuals enter diapause induced by photoperiod, modified by temperature, thus being potentially multivoltine. The spruce beetle Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae) infests all spruce species in its natural range in North America. A facultative prepupal diapause is averted by relatively warm temperatures, resulting in a univoltine life cycle, whereas cool temperatures induce prepupal diapause leading to a semivoltine cycle. An adult obligate diapause in D. rufipennis could limit bi- or multivoltinism. We discuss and compare the influence of diapause and overwinter survival on voltinism and population dynamics of these two species in a changing climate and provide an outlook on future research.

  18. On mycorrhiza development of spruces and firs in damaged stands

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    Ritter, T.; Weber, G.; Kottke, I.; Oberwinkler, F.


    The authors studied the very fine roots of sick spruces and firs and established the following: 1. a surprising stability of mycorrhiza development, 2. differences in the dynamism of development and 3. modifications in the composition of the accompanying microfungi. The results suggest connections in the chain of causes of forest disease which have received little attention so far.

  19. Animal damage to young spruce and fir in Maine (United States)

    Barton M. Blum


    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...

  20. Putrescine: a marker of stress in red spruce trees (United States)

    Rakesk Minocha; Walter C. Shortle; Gregory B. Lawrence; Mark B. David; Subhash C. Minocha


    Aluminum (Al) has been suggested to be an important stress factor in forest decline due to its mobilization in soil following atmospheric deposition of acidic pollutants. A major goal of our research is to develop physiological and biochemical markers of stress in trees using cell cultures and whole plants. Needles of red spruce (Picea rubens)...

  1. Pulp and paper production from Spruce wood with kraft and ...

    African Journals Online (AJOL)



    Mar 15, 2010 ... Full Length Research Paper. Pulp and paper production from Spruce wood with kraft and modified kraft methods. Ahmet Tutus1*, Saim Ates2 and Ilhan Deniz3. 1Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University (KSU) 46100,. Kahramanmaras, Turkey.

  2. The incidence of dwarf mistletoe in Minnesota black spruce stands detected by operational inventories (United States)

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


    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...

  3. Lab and Field Warming Similarly Advance Germination Date and Limit Germination Rate for High and Low Elevation Provenances of Two Widespread Subalpine Conifers

    Directory of Open Access Journals (Sweden)

    Lara M. Kueppers


    Full Text Available Accurately predicting upslope shifts in subalpine tree ranges with warming requires understanding how future forest populations will be affected by climate change, as these are the seed sources for new tree line and alpine populations. Early life history stages are particularly sensitive to climate and are also influenced by genetic variation among populations. We tested the climate sensitivity of germination and initial development for two widely distributed subalpine conifers, using controlled-environment growth chambers with one temperature regime from subalpine forest in the Colorado Rocky Mountains and one 5 °C warmer, and two soil moisture levels. We tracked germination rate and timing, rate of seedling development, and seedling morphology for two seed provenances separated by ~300 m elevation. Warming advanced germination timing and initial seedling development by a total of ~2 weeks, advances comparable to mean differences between provenances. Advances were similar for both provenances and species; however, warming reduced the overall germination rate, as did low soil moisture, only for Picea engelmannii. A three-year field warming and watering experiment planted with the same species and provenances yielded responses qualitatively consistent with the lab trials. Together these experiments indicate that in a warmer, drier climate, P. engelmannii germination, and thus regeneration, could decline, which could lead to declining subalpine forest populations, while Pinus flexilis forest populations could remain robust as a seed source for upslope range shifts.

  4. Climate-Induced Mortality of Spruce Stands in Belarus (United States)

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


    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.

  5. Net ecosystem exchange of carbon dioxide and evapotranspiration response of a high elevation Rocky Mountain (Wyoming, USA) forest to a bark beetle epidemic (United States)

    Frank, J. M.; Massman, W. J.; Ewers, B. E.


    Bark beetle epidemics have caused major disturbance in the forests of western North America where significant tree mortality alters the balance of ecosystem photosynthesis, carbon balance, and water exchange. In this study we investigate the change in the growing-season light-response of net ecosystem exchange of carbon dioxide (NEE) and evapotranspiration (ET) in a high elevation Rocky Mountain forest over the three years preceding and three years following a bark beetle outbreak. The GLEES AmeriFlux site (southeastern Wyoming, USA) is located in a high elevation subalpine forest dominated by Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) and recently experienced an epidemic of spruce beetle (Dendroctonus rufipennis). The peak beetle outbreak occurred in 2008, and has impacted 35% of the stems and 90% of the basal area of Engelmann spruce, which accounts for 30% of the trees and 70% of the basal area of the forest. Two semi-empirical light response curves for eddy-covariance carbon flux were compared, with a logistic sigmoid performing better because of residual bias than a rectangular hyperbola (Michaelis-Menten) at estimating the quantum yield of photosynthesis. In the first two years after the peak beetle outbreak the original quantum yield of 0.015 mol mol-1 was reduced by 25%. By the third year it was reduced by a half, which was composed of declines of 45% in the ecosystem's responses to diffuse radiation and 60% to direct radiation. The light-saturated rate of photosynthesis decreased by 10% in the first two years post outbreak, and fell by 40% in the third year. After the peak outbreak, the cumulative NEE over the growing season was reduced by over a half from a sink of 185 gC m-2 to 80 gC m-2, and by the third year it was reduced to near zero, or carbon neutral. The change in the ET response to light was similar in all years after the peak outbreak where the slope of the response curve was decreased by 25%. This led to a

  6. Drought-triggered western spruce budworm outbreaks in the Interior Pacific Northwest: A multi-century dendrochronological record (United States)

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


    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...

  7. Effects of calcium fertilization and acid mist on calcium concentration and cold tolerance of red spruce needles (United States)

    G. R. Strimbeck; David R. Vann; Arthur H. Johnson


    Several studies have shown that exposure to acid mist impairs cold tolerance of red spruce foliage, predisposing it to winter injury, which appears to be a major factor in the decline of montane populations of the species. Other studies have shown increases in calcium (Ca) concentration in canopy throughfall in montane spruce-fir forests, and decreases in foliar Ca...

  8. Communities of epigeic beetles in tree line from montane spruce forest to secondary meadow in the different stage of the forest decline in the area of Modrava (Bohemian forest, Czech Republic

    Directory of Open Access Journals (Sweden)

    Boháč Jaroslav


    Full Text Available Communities of epigeic beetles were studied using pitfall trapping on 10 plots with the different stage of decline and clear-cut plots without coarse woody debris. Species richness (number of all species, S, total species diversity as the Shannon-Wiener’s index (H and equitability (e were calculated in the DBreleve. The Ward’s method of hierarchical agglomerative classification with Euclidean distance was used for the differentiation of the communities on the plots. Species data for this analyse were represented by logarithm-transformed activities [log(x+1]. The single-factor analysis of variance (ANOVA was used for statistical testing of differences in structural parameters (e.g. species richness and diversity amongst distinguished groups of the plots. The species diversity and activity differs on glades without trees and coarse woody debris. The highest number of species was found in clear-cut areas. The lowest number of species was found on the plots with the living forest particularly invaded by bark beetle. This fact is caused by the fact that the clear-cut plots are invaded by ubiquitous and anthropotolerant species with good migration possibilities. These species are adapted to habitats without trees and are able to leave even in the habitats with very sparse or without vegetation. Species living in the forest even under the bark beetle attack are often stenotopic and adapted to the forest microclimate (higher humidity and low average temperature. These species are very sensitive to great difference in the daily changes of microclimate. The study of beetle communities support the hypothesis that the keeping of dead tree stands on plots after bark beetle outbreak is better for biodiversity conservation than the cutting down of trees and the abolishment of stems.

  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 (United States)

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


    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,...

  10. A dynamic organic soil biogeochemical model for simulating the effects of wildfire on soil environmental conditions and carbon dynamics of black spruce forests (United States)

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


    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...

  11. Forest Biophysical Parameters (SNF) (United States)

    National Aeronautics and Space Administration — Biophysical parameters (DBH, NPP, biomass, bark area index, LAI, subcanopy LAI) by study site for Aspen and Spruce in the Superior National Forest, MN (SNF)

  12. Forest Biophysical Parameters (SNF) (United States)

    National Aeronautics and Space Administration — ABSTRACT: Biophysical parameters (DBH, NPP, biomass, bark area index, LAI, subcanopy LAI) by study site for Aspen and Spruce in the Superior National Forest, MN (SNF)

  13. An eddy covariance study of a spruce beetle outbreak on summertime evapotranspiration and ecosystem CO2 exchange and winter sublimation dynamics (United States)

    Frank, John Michael

    Water and carbon cycles are important from ecosystem to global scales because of their feedbacks with climate change and natural disturbance. In order to quantify both primary and compensating responses in an ecosystem under disturbance, an approach that observes the ecosystem in its entirety is preferred. In recent decades, the eddy covariance technique has become ubiquitous in modern ecosystem studies because its fundamental measurement scale integrates across an ecosystem. Yet, across flux networks a trend towards energy imbalance has implicated a systematic bias in these measurements that has no mechanistic explanation. This dissertation concentrates on a historical transducer shadowing correction for sonic anemometers, the fundamental instrument in eddy covariance studies, and whether the omission of it can explain these underestimated ecosystem fluxes. It then focuses on the response of water and carbon processes in a subalpine spruce-fir forest in southeastern Wyoming, USA that experienced 80% forested basal area mortality following a spruce beetle outbreak. To evaluate an uncertainty in eddy covariance measurements, a novel experiment is devised to test the consistency to which an omnidirectional sonic anemometer can measure the three dimensions, to compare of the effect of different designs and different manufacturers to link an underestimate in vertical wind velocity to the lack of transducer shadowing correction, and to construct a Bayesian model to estimate the three dimensional shadowing correction required to fix the problem. Results show that at the 60% of ecosystem flux sites in North American that use this equipment, their ecosystem flux measurements are probably underestimated by 8-12%. During the growing season, the change in ecosystem processes due to disturbance are explained through the physiological response of dying spruce trees and their observed mortality. Evapotranspiration declines immediately following the attack because of hydraulic

  14. Pelletizing properties of torrefied spruce

    DEFF Research Database (Denmark)

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


    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...

  15. 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 (United States)

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


    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...

  16. Diapause and overwintering of two spruce bark beetle species (United States)

    Hansen, E. Matthew; Schopf, Axel; Ragland, Gregory J.; Stauffer, Christian; Bentz, Barbara J.


    Abstract Diapause, a strategy to endure unfavourable conditions (e.g. cold winters) is commonly found in ectothermic organisms and is characterized by an arrest of development and reproduction, a reduction of metabolic rate, and an increased resistance to adversity. Diapause, in addition to adaptations for surviving low winter temperatures, significantly influences phenology, voltinism and ultimately population growth. We review the literature on diapause and overwintering behaviour of two bark beetle species that affect spruce‐dominated forests in the northern hemisphere, and describe and compare how these strategies can influence population dynamics. The European spruce bark beetle Ips typographus (L.) (Coleoptera, Curculionidae) is the most important forest pest of Norway spruce in Europe. It enters an adult reproductive diapause that might be either facultative or obligate. Obligate diapausing beetles are considered strictly univoltine, entering this dormancy type regardless of environmental cues. Facultative diapausing individuals enter diapause induced by photoperiod, modified by temperature, thus being potentially multivoltine. The spruce beetle Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae) infests all spruce species in its natural range in North America. A facultative prepupal diapause is averted by relatively warm temperatures, resulting in a univoltine life cycle, whereas cool temperatures induce prepupal diapause leading to a semivoltine cycle. An adult obligate diapause in D. rufipennis could limit bi‐ or multivoltinism. We discuss and compare the influence of diapause and overwinter survival on voltinism and population dynamics of these two species in a changing climate and provide an outlook on future research. PMID:28979060

  17. Survival and growth patterns of white spruce (Picea glauca [Moench] Voss) rangewide provenances and their implications for climate change adaptation


    Lu, Pengxin; Parker, William H; Cherry, Marilyn; Colombo, Steve; William C. Parker; Man, Rongzhou; Roubal, Ngaire


    Intraspecific assisted migration (ISAM) through seed transfer during artificial forest regeneration has been suggested as an adaptation strategy to enhance forest resilience and productivity under future climate. In this study, we assessed the risks and benefits of ISAM in white spruce based on long-term and multilocation, rangewide provenance test data. Our results indicate that the adaptive capacity and growth potential of white spruce varied considerably among 245 range-wide provenances sa...

  18. FIBER handbook: a growth model for spruce-fir and northern hardwood types (United States)

    Dale S. Solomon; Richard A. Hosmer; Homer T., Jr. Hayslett; Homer T. Hayslett


    A matrix model, FIBER, has been developed to provide the forest manager with a means of simulating the management and growth of forest stands in the Northeast. Instructional material is presented for the management of even-aged and multi-aged spruce-fir, mixedwood, and northern hardwood stands. FIBER allows the user to simulate a range of silvicultural treatments for a...

  19. Braconid (Hymenoptera, Braconidae) parasitoids of bark beetles in upland spruce stands of the Czech Republic (United States)

    Aural Lozan; Jiri Zeleny


    Several species of bark beetles occur frequently in the upland spruce forests of the Czech Republic; some of them are serious pests that may cause vast destruction of forest stands. In the last decade, a complex of several species from the genera Ips, Pityogenes and Polygraphus contributed to large-scale devastation of thousand...

  20. Climate driven changes in Engelmann spruce stands at timberline in the La Sal Mountains (United States)

    James F. Fowler; Steven Overby; Barb Smith


    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...

  1. Comparative indicators of genetic variability and bark beetle infestation intensity in populations of norway spruce (Picea abies (L.) Karst.) in Bosnia and Herzegovina


    Ballian, Dalibor; Dautbašić, Mirza; Božič, Gregor


    This study sets out comparative indicators of Norway spruce Picea abies (L.) Karst. populations in Bosnia and Herzegovina, based on an evaluation of the attack power of bark beetles Ips typographus L. and Pityogenes chalcographus L. and the decline of spruce within the populations sampled for genetic analysis. Twelve natural forest stands and one plantation were analyzed. The average numbers of desiccated Norway spruces per stand and isoenzyme gene markers were used for comparison purposes...

  2. White spruce meets black spruce: dispersal, postfire establishment, and growth in a warming climate (United States)

    C. Wirth; J.W. Lichstein; J. Dushoff; A. Chen; F.S.III. Chapin


    Local distributions of black spruce (Picea mariana) and white spruce (Picea glauca) are largely determined by edaphic and topographic factors in the interior of Alaska, with black spruce dominant on moist permafrost sites and white spruce dominant on drier upland sites. Given the recent evidence for climate warming and...

  3. Behavioral and Reproductive Response of White Pine Weevil (Pissodes strobi to Resistant and Susceptible Sitka Spruce (Picea sitchensis

    Directory of Open Access Journals (Sweden)

    Jeanne A. Robert


    Full Text Available White pine weevil (Pissodes strobi, Peck. is a native forest insect pest in the Pacific Northwest of North America that attacks species of spruce (Picea spp. and pine (Pinus spp.. Young Sitka spruce [Picea sitchensis (Bong. Carr.] trees are particularly susceptible to weevil attack. Pockets of naturally occurring Sitka spruce resistance have been identified in high weevil hazard areas in coastal British Columbia. In this study, we characterize behavioral, physiological and reproductive responses of weevils to an extremely resistant Sitka spruce genotype (H898 in comparison to a highly susceptible genotype (Q903. The experiments relied on a large number of three-year-old clonally propagated trees and were therefore restricted to two contrasting Sitka spruce genotypes. When exposed to resistant trees, both male and female weevils were deterred during host selection and mating, females showed delayed or reduced ovary development, and successful reproduction of weevils was prevented on resistant trees.

  4. Mice and voles prefer spruce seeds (United States)

    Herschel G. Abbott; Arthur C. Hart


    When spruce-fir stands in the Northeast are cut, balsam fir seedlings often predominate in the regeneration that follows. Most landowners would prefer to have the spruce; but they do not get it, and they wonder why.

  5. Forests (United States)

    Louis R. Iverson; Mark W. Schwartz


    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.

  6. Hydraulic adjustment in jack pine and black spruce seedlings under controlled cycles of dehydration and rehydration. (United States)

    Blake, Terence J.; Li, Jiyue


    Drought adjustments were compared in black spruce (Picea mariana[Mill] B.S.P), and jack pine (Pinus banksiana[Lamb.]) by subjecting seedlings to five cycles of dehydration and rehydration. A computer-controlled root misting chamber system, supplied low (-1.5 MPa), moderate (-2.0 MPa), and severe (-2.5 MPa) dehydration, respectively, in cycles 1, 3 and 5. Although cell water relations failed to adjust to chronic dehydration, there was limited osmotic adjustment in black spruce (cycle 3), and water was re-allocated from the apoplast to the symplast in jack pine (cycles 1 and 3). Dehydration postponement was more important than dehydration tolerance. Jack pine was better able to postpone dehydration than black spruce. Specific conductivity, the hydraulic conductivity per unit stem cross-sectional area, was lower in jack pine and slower to decline during chronic dehydration. When specific conductivity was corrected for the greater leaf area in black spruce, the leaf-specific conductivity did not differ in the two species. There was no increase in needle leakage in jack pine and stomata in jack pine seedlings reopened fully after rehydration. Black spruce was more of a 'water spender', and less water stress (-2.0 MPa, cycle 3) was required to lower specific conductivity, compared to jack pine (-2.5 MPa, cycle 5). Leakage from needle membranes increased in black spruce, and stomata failed to reopen after rewatering (cycles 3 and 5). A greater needle area, smaller root system, and a higher specific conductivity lowered the water stress threshold for cavitation in black spruce, which is confined to moister sites in the boreal forest. Jack pine had a larger root system, smaller needle area and lower specific conductivity than black spruce. Because of these static features, jack pine is more drought tolerant and it is often found on sites that are too hot and dry for black spruce.

  7. The forest fire season at different elevations in Idaho (United States)

    J. A. Larsen


    In any fire-ridden forest region, such as north Idaho, there is great need for a tangible basis by which to judge the length and the intensity of the fire season in different forest types and at different elevations. The major and natural forest types, such as the western yellow pine forests, the western white-pine forests, and the subalpine forests occur in...

  8. Modelling spruce bark beetle infestation probability (United States)

    Paulius Zolubas; Jose Negron; A. Steven Munson


    Spruce bark beetle (Ips typographus L.) risk model, based on pure Norway spruce (Picea abies Karst.) stand characteristics in experimental and control plots was developed using classification and regression tree statistical technique under endemic pest population density. The most significant variable in spruce bark beetle...

  9. Maine's forests 2008 (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


    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...

  10. Development of soil water regime under spruce stands

    Directory of Open Access Journals (Sweden)

    Tužinský Ladislav


    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.

  11. 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. (United States)

    Suchara, I; Rulík, P; Hůlka, J; Pilátová, H


    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.

  12. Northern forests, Chapter 7 (United States)

    L.H. Pardo; C.L. Goodale; E.A. Lilleskov; L.H. Geiser


    The Northern Forests ecological region spans much of Canada, from Saskatchewan to Newfoundland; its southern portion extends into the northern United States (CEC 1997). The U.S. component includes the northern hardwood and spruce-fir forest types and encompasses parts of the Northeast (mountainous regions in Pennsylvania, New York, New Jersey, Connecticut,...

  13. Soil ecological interactions: comparisons between tropical and subalpine forests (United States)

    Grizelle Gonzalez; Ruth E. Ley; Steven K. Schmidt; Xiaoming Zou; Timothy R. Seastedt


    Soil fauna can influence soil processes through interactions with the microbial community. Due to the complexity of the functional roles of fauna and their effects on microbes, little consensus has been reached on the extent to which soil fauna can regulate microbial activities. We quantified soil microbial biomass and maximum growth rates in control and fauna-excluded...

  14. Evaluating the Importance of Plant Functional Traits: the Subalpine and Alpine (United States)

    Sanchez, A.; Smith, W. K.


    Over the past several decades, researchers have attempted to characterize plant groups according to traits that are considered functional, i.e. contributing significantly to fitness. Due to the complexity of measuring fitness, the capability for photosynthetic carbon gain is often used as a proxy. Thus, this approach correlates structural differences to photosynthetic performance, especially those differences that are known to be associated with photosynthesis, are easily measured and inexpensive. At the often sharp boundary between the subalpine forest and alpine community (treeline ecotone), plant structural traits change dramatically, i.e. tall evergreen trees give way abruptly to low-stature shrubs, grasses, forbs, and herbs. Yet, the differences in functional traits, so abundant in the literature for a variety of species and communities, have not been compared contiguous communities such as the subalpine forest and alpine. Can differences in functional traits already identified in the literature also be used to characterize species of these two contrasting communities? Or are there other traits that are most functional and/or, possibly, unique to each community and not the most popular traits reported so far in the literature. Also, does the community structure itself help determine functional traits? For example, the top ten most frequently studied traits (145 total papers from approximately 63 different refereed journals) considered functional include the following (% of the 145 publications): specific leaf area or mass (SLA or SLM 39%), plant height (36%), leaf nitrogen content (34%), leaf size (19%), leaf area (16%), leaf photosynthetic performance (15%), leaf dry matter content (LDMC 15%), leaf mass per unit leaf area (LMA 15%), leaf thickness (15%), and seed mass (14%). In addition, another 120 traits were mentioned as functional, although all fell below a 14% citation rate. Particular focus was placed on this group due to the possibility that they might

  15. Population dynamics of the small spruce whorl scale (Physokermes hemicryphus DALM. Homoptera, Coccidea) taking into account forest damage from air pollution in various spruce sites in Baden-Wuerttemberg; Populationsdynamik der kleinen Fichtenquirlschildlaus (Physokermes hemicryphus DALM. Homoptera, Coccidea) unter Beruecksichtigung der Waldschaeden durch Luftverschmutzung an verschiedenen Fichtenstandorten in Baden-Wuerttemberg

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, W.


    From 1984 to 1986 the mass variation of Physokermes hemicryphus was investigated in spruce stands in the field damaged in varying degrees by air pollutants. The influence of the nutritive element contents of potassium, calcium, phosphorus, magnesium and nitrogen on needle weight, needle loss, and the population density of Physokermes hemicryphus was examined. The sites of investigation were in southern Germany. Further tests were conducted in 1986 in the open-top chambers of the University of Hohenheim, on the influence of defined air pollutants or combinations of air pollutants. Specifically, their effect on the nutritive element content of cloned young spruces, and their influence on the size of Physokermes hemicryphus specimens were assessed. The mineral content of honey dew was analysed in addition. Spruce stands in southern Germany which are seriously damaged by air pollutants tend to have below-average rates of colonization with whorl scales. During the period of investigation, the population density of Physokermes hemicryphus declined in all sites. On average, 44% of the decline was accounted for by parasites and predators. (orig./UWA) [Deutsch] Im Freiland wurde an Fichtenbestaenden die durch Luftschadstoffe verschieden stark beschaedigt waren, in den Jahren 1984-1986 der Massenwechsel von Physokermes hemicryphus untersucht. Dabei wurde der Einfluss der Naehrelementgehalte Kalium, Kalzium, Phosphor, Magnesium und Stickstoff auf das Nadelgewicht, den Nadelverlust und die Populationsdichte von Physokermes hemicryphus geprueft. Die Untersuchungsstandorte lagen in Suedwestdeutschland. In den Open-Top Kammern der Universitaet Hohenheim erfolgten im Jahr 1986 weitere Untersuchungen zum Einfluss definierter Luftschadstoffe bzw. Luftschadstoffkombinationen. Geprueft wurden deren Effekt auf den Naehrelementgehalt von klonierten Jungfichten und die Auswirkungen auf die Koerpergroesse von Physokermes hemicryphus. Weiterhin wurde dort der Mineralstoffgehalt im Honigtau

  16. 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


    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 Sc...... hypotheses, and beech and spruce supported the economy of scale, predator satiation and resource allocation hypotheses....

  17. Provenance variability in nursery growth of subalpine fir (United States)

    Charlie Cartwright; Cheng Ying


    Subalpine fir (Abies lasiocarpa [Hook] Nutt.) is a wide-ranging, high-elevation species in the interior of British Columbia. It is commonly harvested for lumber, but replanting of it is limited. Some reticence is based upon wood quality and rate of growth, but there are also seed and nursery culturing difficulties. This study investigated seedling growth traits of 111...

  18. Wood quality and value production in mixed fir-spruce-beech stands: long-term research in the Western Carpathians

    Directory of Open Access Journals (Sweden)

    Petráš Rudolf


    Full Text Available Stem quality and damage was evaluated in mixed spruce-fir-beech stands. Moreover, an assortments structure was determined with their financial value. Results were compared with pure spruce (Picea abies [L.] Karst., fir (Abies alba Mill. and beech (Fagus sylvatica L. stands. Repeated measurements on 31 long-term research plots, stand assortment models, assortment yield models and value yield models were used. Stem quality of fir and spruce was only slightly lower in mixed stands compared to pure stands but beech stem quality was considerably worse in mixed stands. Fir and spruce had slightly lower proportions of better IIIA quality logs and higher proportions of IIIB quality in mixed stands. Beech had worse assortment structure than spruce and fir, in general. Pure beech stands had higher proportions of better I–IIIA quality assortments than mixed stands by 1–7%. Fir and spruce average value production (€ m−3 culminated at about 56 and 62 cm mean diameters. Almost the same value production was found in pure stands. In these stands it culminated at the mean diameter of 58 and 60 cm. Beech produced substantially less value on the same sites. In mixed stands, its value production culminated at the mean diameter of 40 cm. In pure stands, it culminated at the mean diameter of 36 cm. Although the production was found to be similar in both mixed and pure forests, higher damage intensity and less stem quality in mixed forests suggest that the pure forests can be more profitable.

  19. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce (United States)

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison


    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...

  20. 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


    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

  1. 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.


    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...


    • 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...

  3. Multipartite Symbioses Among Fungi, Mites, Nematodes, and the Spruce Beetle, Dendroctonus rufipennis. (United States)

    Yasmin Cardoza; John Moser; Kier Klepzizg; Raffa Kenneth


    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...

  4. Age and size effects on seed productivity of northern black spruce (United States)

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


    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....

  5. Juvenility and serial vegetative propagation of Norway spruce clones (Picea abies Karst.). (United States)

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


    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...

  6. 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


    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.)...

  7. Negative feedbacks on bark beetle outbreaks: widespread and severe spruce beetle infestation restricts subsequent infestation.

    Directory of Open Access Journals (Sweden)

    Sarah J Hart

    Full Text Available Understanding disturbance interactions and their ecological consequences remains a major challenge for research on the response of forests to a changing climate. When, where, and how one disturbance may alter the severity, extent, or occurrence probability of a subsequent disturbance is encapsulated by the concept of linked disturbances. Here, we evaluated 1 how climate and forest habitat variables, including disturbance history, interact to drive 2000s spruce beetle (Dendroctonus rufipennis infestation of Engelmann spruce (Picea engelmannii across the Southern Rocky Mountains; and 2 how previous spruce beetle infestation affects subsequent infestation across the Flat Tops Wilderness in northwestern Colorado, which experienced a severe landscape-scale spruce beetle infestation in the 1940s. We hypothesized that drought and warm temperatures would promote infestation, whereas small diameter and non-host trees, which may reflect past disturbance by spruce beetles, would inhibit infestation. Across the Southern Rocky Mountains, we found that climate and forest structure interacted to drive the 2000s infestation. Within the Flat Tops study area we found that stands infested in the 1940s were composed of higher proportions of small diameter and non-host trees ca. 60 years later. In this area, the 2000s infestation was constrained by a paucity of large diameter host trees (> 23 cm at diameter breast height, not climate. This suggests that there has not been sufficient time for trees to grow large enough to become susceptible to infestation. Concordantly, we found no overlap between areas affected by the 1940s infestation and the current infestation. These results show a severe spruce beetle infestation, which results in the depletion of susceptible hosts, can create a landscape template reducing the potential for future infestations.

  8. Invasion of subalpine meadows by lodgepole pine in Yellowstone National Park, Wyoming, USA

    Energy Technology Data Exchange (ETDEWEB)

    Jakubos, B.; Romme, W.H. (Fort Lewis College, Durango, CO (United States))


    Many of the dry and mesic subalpine meadows in Yellowstone National Park are bordered by bands of small lodgepole pine trees. The authors asked whether these stands of small trees represent a directional process of meadow invasion, or alternatively, (1) small patches of postfire succession or; (2) more-or-less stable populations of trees having small stature because of adverse site conditions. Transect studies revealed that the bands of small trees were consistently younger than adjacent forest stands of obvious fire origin, that they lacked any evidence of fire, and that the trees were progressively younger as they approached the meadow. Soils under the young trees generally were more similar to meadow soils than to coniferous forest soils. The authors concluded, therefore, that meadow invasion has been occurring as a directional process since at least the mid- to late 1800s. Frequency of tree establishment in two dry meadows was positively correlated with mean June temperature and total summer precipitation (R[sup 2] = 0.49, P<0.0001, multiple stepwise regression). Thus, the major cause of tree invasion into dry meadows appears to be a regional climatic trend towards warmer and wetter growing seasons since the end of the Little Ice Age. Tree establishment in two mesic meadows was more weakly and inconsistently correlated with weather variables. Thus, the mechanism of invasion of mesic meadows may involve interactions of episodic seed crops and microhabitat changes at the forest border, as well as regional climatic variability. 30 refs., 7 figs., 1 tab.

  9. Changes after partial cutting of a spruce-fir stand in Maine (United States)

    Arthur C. Hart


    In 1945 a partial-cutting experiment in spruce-fir silviculture was begun by the Penobscot Research Center of the Northeastern Forest Experiment Station. The Eastern Pulp Wood Company of Calais, Maine, made available for the study a tract of forest land, in Dyer Township, Washington County, Maine. This 20.6-acre tract is part of a large area that had been burned over...

  10. Long-Term Exposure of Sitka Spruce Seedlings to Trichloroacetic Acid


    Cape, Neil; Reeves, Nicholas M; Schroder, Peter; Heal, Mathew R


    Trichloroacetic acid (TCA) has been implicated as an airborne pollutant responsible for adverse effects on forest health. There is considerable debate as to whether TCA observed in trees and forest soils is derived from atmospheric deposition or from in situ production. This experiment reports the results from treating 4-year-old Sitka spruce ( Picea sitchensis(Bong.) Carr) plants in a greenhouse over a growing season with TCA supplied either to the soil or to the foli...

  11. Testing remote sensing estimates of bark beetle induced mortality in lodgepole pine and Engelmann spruce with ground data (United States)

    King, A.; Ewers, B. E.; Sivanpillai, R.; Pendall, E.


    Bark beetles have caused widespread regional mortality in both lodgepole and Engelmann spruce forests across western North America, and while studies have addressed the impact on water partitioning caused by the mountain pine beetle, spruce beetle which often occur at high elevations with larger snowpack might have a disproportional impact. Beetle caused mortality can have significant effects on the hydrology of a watershed and therefore needs to be considered when evaluating increased runoff. The objective of this project was to generate maps showing beetle caused mortality for lodgepole pine and spruce fir forests that capture changes to the landscape to improve hydrologic models. Our study area in southeast Wyoming covered an area of approximately 2 by 4 km from 2700 to 2800m elevation range. High spatial resolution (0.5m) aerial imagery acquired by the Airborne Environmental Research Observational Camera (AEROCam) in fall 2011, provided by the Upper Midwest Aerospace Consortium (UMAC), was manually classified into four conifer thematic classes: live and dead lodgepole pine, and live and dead spruce/fir. The classified high resolution image was then verified by tree surveys conducted July-September, 2012 documenting species, tree diameter at breast height (dbh), and the stage of beetle infestation for each tree. After verification the high resolution aerial images were used to train and evaluate the accuracy of a supervised classification of a Landsat 5 Thematic Mapper image from the same time period and area. The preliminary results of a supervised classification show that map accuracy was 57%, 77%, 44%, and 83% for lodgepole live and dead, and spruce/fir live and dead respectively. The highest commission error, 24%, was for dead lodgepole pine being falsely labeled dead spruce/fir. The second highest commission error, 22%, was for live spruce/fir falsely labeled dead spruce/fir. The results indicate high spectral overlap between dead spruce/fir and dead

  12. Ammonium assmilation in spruce ectomycorrhizas

    Energy Technology Data Exchange (ETDEWEB)

    Chalot, M.; Brun, A.; Botton, B. (Univ. of nancy, Vandoeuvre-les-Nancy (France)); Stewart, G. (University College, London (England))


    Assimilation of labelled NH{sub 4}{sup +} into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH{sub 4}{sup +} 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{sub 4}{sup +} 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 {sup 15}N enrichment in both amino and amido groups of glutamine. In contrast, the {sup 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.

  13. 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


    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.

  14. Silvical characteristics of red spruce (Picea rubens) (United States)

    Arthur C. Hart


    Red spruce (Picea rubens Sarg.) is not only the most important of the spruces; it is also one of the most important of all the conifers in northeastern North America. It is a tree of many uses. The paper industry relies heavily on it for pulpwood; in the variety of its other uses it rivals white pine.

  15. Use of cosmogenic 35S for comparing ages of water from three alpine-subalpine basins in the Colorado Front Range (United States)

    Sueker, J.K.; Turk, J.T.; Michel, R.L.


    High-elevation basins in Colorado are a major source of water for the central and western United States; however, acidic deposition may affect the quality of this water. Water that is retained in a basin for a longer period of time may be less impacted by acidic deposition. Sulfur-35 (35S), a short-lived isotope of sulfur (t( 1/2 ) = 87 days), is useful for studying short-time scale hydrologic processes in basins where biological influences and water/rock interactions are minimal. When sulfate response in a basin is conservative, the age of water may be assumed to be that of the dissolved sulfate in it. Three alpine-subalpine basins on granitic terrain in Colorado were investigated to determine the influence of basin morphology on the residence time of water in the basins. Fern and Spruce Creek basins are glaciated and accumulate deep snowpacks during the winter. These basins have hydrologic and chemical characteristics typical of systems with rapid hydrologic response times. The age of sulfate leaving these basins, determined from the activity of 35S, averages around 200 days. In contrast, Boulder Brook basin has broad, gentle slopes and an extensive cover of surficial debris. Its area above treeline, about one-half of the basin, is blown free of snow during the winter. Variations in flow and solute concentrations in Boulder Brook are quite small compared to Fern and Spruce Creeks. After peak snowmelt, sulfate in Boulder Brook is about 200 days older than sulfate in Fern and Spruce Creeks. This indicates a substantial source of older sulfate (lacking 35S) that is probably provided from water stored in pore spaces of surficial debris in Boulder Brook basin.

  16. Spruce aphid (Elatobium abietinum Walker) (Hemiptera: Aphididae) [Chapter XXIV (United States)

    Ann M. Lynch


    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) (

  17. Damage by the Sitka spruce weevil (Pissodes strobi) and growth patterns for 10 spruce species and hybrids over 26 years in the Pacific Northwest. (United States)

    Russel G. Mitchell; Kenneth H. Wright; Norman E. Johnson


    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...

  18. Evaluation of storage and filtration protocols for alpine/subalpine lake water quality samples (United States)

    John L. Korfmacher; Robert C. Musselman


    Many government agencies and other organizations sample natural alpine and subalpine surface waters using varying protocols for sample storage and filtration. Simplification of protocols would be beneficial if it could be shown that sample quality is unaffected. In this study, samples collected from low ionic strength waters in alpine and subalpine lake inlets...

  19. N cycling in SPRUCE (Spruce Peatlands Response Under ... (United States)

    Peatlands located in boreal regions make up a third of global wetland area and are expected to have the highest temperature increases in response to climate change. As climate warms, we expect peat decomposition may accelerate, altering the cycling of nitrogen. Alterations in the nitrogen cycle can have consequences on NO3, NH4 availability or pollution, and potentially increase nitrous oxide (N2O) emissions, a persistent greenhouse gas (GHG). These consequences can cascade to altering whole ecosystem functions and effecting human health.We are investigating nitrogen cycling response to elevated temperature and CO2 in a boreal peatland. Spruce and Peatland Responses Under Climate and Environmental Change (SPRUCE) project initiated soil warming in 2014 in ten peatland mesocosms (five temperature treatments from ambient (+0°C) to +9°C) and elevated CO2 in half of the mesocosms in 2016. Peat cores at three depths (acrotelm, catotelm, deep peat) were analyzed in the laboratory for denitrification, nitrification, and ammonification. We expect denitrification, nitrification, and ammonification rates to increase, and denitrification efficiency to decrease with rising temperatures- potentially contaminating water resources with NO3, NH4 and increase N2O concentrations in our atmosphere. This research will enhance the scientific understanding of how nitrogen cycling, an important functional eco-service, responds under environmental conditions including elevated CO2

  20. Estimating forest species composition using a multi-sensor approach (United States)

    P.T. Wolter


    The magnitude, duration, and frequency of forest disturbance caused by the spruce budworm and forest tent caterpillar has 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 the increase in dominance of host tree species. Modeling approaches...

  1. CO2 flux studies of different hemiboreal forest ecosystems (United States)

    Krasnova, Alisa; Krasnov, Dmitrii; Noe, Steffen M.; Uri, Veiko; Mander, Ülo; Niinemets, Ülo; Soosaar, Kaido


    Hemiboreal zone is a transition between boreal and temperate zones characterized by the combination of climatic and edaphic conditions inherent in both zones. Hemiboreal forests are typically presented by mixed forests types with different ratios of deciduous and conifer tree species. Dominating tree species composition affects the functioning of forest ecosystem and its influence on biogeochemical cycles. We present the result of ecosystem scale CO2 eddy-covariance fluxes research conducted in 4 ecosystems (3 forests sites and 1 clear-cut area) of hemiboreal zone in Estonia. All 4 sites were developing under similar climatic conditions, but different forest management practices resulted in different composition of dominating tree species: pine forest with spruce trees as a second layer (Soontaga site); spruce/birch forest with single alder trees (Liispõllu site); forest presented by sectors of pine, spruce, birch and clearcut areas (SMEAR Estonia site); 5-years old clearcut area (Kõnnu site).

  2. A conifer genomics resource of 200,000 spruce (Picea spp. ESTs and 6,464 high-quality, sequence-finished full-length cDNAs for Sitka spruce (Picea sitchensis

    Directory of Open Access Journals (Sweden)

    Holt Robert A


    Full Text Available Abstract Background Members of the pine family (Pinaceae, especially species of spruce (Picea spp. and pine (Pinus spp., dominate many of the world's temperate and boreal forests. These conifer forests are of critical importance for global ecosystem stability and biodiversity. They also provide the majority of the world's wood and fiber supply and serve as a renewable resource for other industrial biomaterials. In contrast to angiosperms, functional and comparative genomics research on conifers, or other gymnosperms, is limited by the lack of a relevant reference genome sequence. Sequence-finished full-length (FLcDNAs and large collections of expressed sequence tags (ESTs are essential for gene discovery, functional genomics, and for future efforts of conifer genome annotation. Results As part of a conifer genomics program to characterize defense against insects and adaptation to local environments, and to discover genes for the production of biomaterials, we developed 20 standard, normalized or full-length enriched cDNA libraries from Sitka spruce (P. sitchensis, white spruce (P. glauca, and interior spruce (P. glauca-engelmannii complex. We sequenced and analyzed 206,875 3'- or 5'-end ESTs from these libraries, and developed a resource of 6,464 high-quality sequence-finished FLcDNAs from Sitka spruce. Clustering and assembly of 147,146 3'-end ESTs resulted in 19,941 contigs and 26,804 singletons, representing 46,745 putative unique transcripts (PUTs. The 6,464 FLcDNAs were all obtained from a single Sitka spruce genotype and represent 5,718 PUTs. Conclusion This paper provides detailed annotation and quality assessment of a large EST and FLcDNA resource for spruce. The 6,464 Sitka spruce FLcDNAs represent the third largest sequence-verified FLcDNA resource for any plant species, behind only rice (Oryza sativa and Arabidopsis (Arabidopsis thaliana, and the only substantial FLcDNA resource for a gymnosperm. Our emphasis on capturing FLcDNAs and

  3. Soil Chemical and Microbial Properties in a Mixed Stand of Spruce and Birch in the Ore Mountains (Germany—A Case Study

    Directory of Open Access Journals (Sweden)

    Karoline Schua


    Full Text Available A major argument for incorporating deciduous tree species in coniferous forest stands is their role in the amelioration and stabilisation of biogeochemical cycles. Current forest management strategies in central Europe aim to increase the area of mixed stands. In order to formulate statements about the ecological effects of mixtures, studies at the stand level are necessary. In a mixed stand of Norway spruce (Picea abies (L. Karst. and silver birch (Betula pendula Roth in the Ore Mountains (Saxony, Germany, the effects of these two tree species on chemical and microbial parameters in the topsoil were studied at one site in the form of a case study. Samples were taken from the O layer and A horizon in areas of the stand influenced by either birch, spruce or a mixture of birch and spruce. The microbial biomass, basal respiration, metabolic quotient, pH-value and the C and N contents and stocks were analysed in the horizons Of, Oh and A. Significantly higher contents of microbial N were observed in the Of and Oh horizons in the birch and in the spruce-birch strata than in the stratum containing only spruce. The same was found with respect to pH-values in the Of horizon and basal respiration in the Oh horizon. Compared to the spruce stratum, in the birch and spruce-birch strata, significantly lower values were found for the contents of organic C and total N in the A horizon. The findings of the case study indicated that single birch trees have significant effects on the chemical and microbial topsoil properties in spruce-dominated stands. Therefore, the admixture of birch in spruce stands may distinctly affect nutrient cycling and may also be relevant for soil carbon sequestration. Further studies of these functional aspects are recommended.

  4. Wildlife of southern forests habitat & management (Chapter 4): Defining the Forests (United States)

    James G. Dickson; Raymond M. Sheffield


    Forests of the South are very diverse and productive. Included among southern forests are the boreal spruce- fir forests of the highest mountain peaks of the Blue Ridge Mountains to the lowest bottomland hardwoods on flood-deposited soil with elevations near sea level. In between are the diverse upland hardwood stands in northerly mountainous areas of the South and...

  5. Remote sensing of the distribution and abundance of host species for spruce budworm in Northern Minnesota and Ontario (United States)

    Peter T. Wolter; Philip A. Townsend; Brian R. Sturtevant; Clayton C. Kingdon


    Insects and disease affect large areas of forest in the U.S. and Canada. Understanding ecosystem impacts of such disturbances requires knowledge of host species distribution patterns on the landscape. In this study, we mapped the distribution and abundance of host species for the spruce budworm (Choristoneura fumiferana) to facilitate landscape scale...

  6. Fire severity mediates climate-driven shifts in understorey community composition of black spruce stands of interior Alaska (United States)

    Emily L. Bernhardt; Teresa N. Hollingsworth; F. Stuart Chapin


    Question: How do pre-fire conditions (community composition and environmental characteristics) and climate-driven disturbance characteristics (fire severity) affect post-fire community composition in black spruce stands? Location: Northern boreal forest, interior Alaska. Methods: We compared plant community composition and environmental stand characteristics in 14...

  7. Effects of permafrost melting on CO2 and CH4 exchange of a poorly drained black spruce lowland (United States)

    Kimberly P. Wickland; Robert G. Striegl; Jason C. Neff; Torsten Sachs


    Permafrost melting is occurring in areas of the boreal forest region where large amounts of carbon (C) are stored in organic soils. We measured soil respiration, net CO2 flux, and net CH4 flux during May-September 2003 and March 2004 in a black spruce lowland in interior Alaska to better understand how permafrost thaw in...

  8. Recent evolution and divergence among populations of a rare Mexican endemic, Chihuahua spruce, following holocene climatic warming (United States)

    F. Thomas Ledig; Virginia Jacob-Cervantes; Paul D. Hodgskiss


    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...

  9. Pollution Critical Load Exceedance and an Extended Growing Season as Modulators of Red Spruce Radial Growth (United States)

    Kosiba, A. M.; Schaberg, P. G.; Engel, B. J.; Rayback, S. A.; Hawley, G. J.; Pontius, J.; Miller, E. K.


    Acidic sulfur (S) and nitrogen (N) deposition depletes cations such as calcium (Ca) from forest soils and has been linked to increases in foliar winter injury that led to the decline of red spruce (Picea rubens Sarg.) in the northeastern United States. We used results from a 30 m resolution steady-state S and N critical load exceedance model for New England to better understand the spatial connections between Ca depletion and red spruce productivity. To calculate exceedance, atmospheric deposition was estimated for a 5-year period (1984-1988) because tree health and productivity declines were expected to be most responsive to high acid loading. We examined how radial growth (basal area increment) of 441 dominant and co-dominant red spruce trees from 37 sites across Vermont and New Hampshire was related to modeled estimates of S and N critical load exceedance. We assessed growth using statistical models with exceedance as a source of variation, but which also included "year" and "elevation class" (to help account for climatic variability) and interactions among factors. Exceedance was significantly and negatively associated with mean growth for the study period (1951-2010) overall, and particularly for the 1980s and 2000s - periods of numerous and/or severe foliar winter injury events. However, climate-related sources of variation (year and elevation) accounted for most of the differences in growth over the chronology. Interestingly, recent growth for red spruce is now the highest recorded over our dendrochronological record for the species - suggesting that the factors shaping growth may be changing. Because red spruce is a temperate conifer that has the capacity to photosynthesize year-round, it is possible that warmer temperatures may be extending the functional growing season of the species thereby fostering increased growth. Data from elevational transects on Mount Mansfield (Vermont's tallest mountain) indicate that warmer spring, summer, fall and even winter

  10. Biomass of Sacrificed Spruce/Aspen (SNF) (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...

  11. Biomass of Sacrificed Spruce/Aspen (SNF) (United States)

    National Aeronautics and Space Administration — ABSTRACT: Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and...

  12. Variation in the extent of ecohydrologic separation in mixed conifer forest (United States)

    Bowers, W.; Williams, D. G.


    It is now widely accepted that water used for tree transpiration can be separate from water that supplies groundwater and streamflow. Broad evidence of such ecohydrologic separation forms the basis for the "two water worlds hypothesis" that challenges commonly held notions of how water moves through terrestrial ecosystems. Isotopic evidence supports that trees take up water from tightly bound soil pore spaces that often is not fully mixed with loosely bound water that eventually flows to groundwater and streams. Conditions that promote ecohydrologic separation and reduce complete mixing of loosely bound and tightly bound water in soil likely vary across soil types and complex topography in forested catchments. We examined the isotopic signature of water in three tree species, bulk soil, loosely bound soil water collected from soil lysimeters, and stream water at three different hillslopes in a mixed confer forest in southeastern Wyoming. Hillslopes differed in aspect and topographic position with corresponding differences in surface energy balance, snowmelt timing, and duration of soil moisture during the dry summer. We expect the magnitude of hydrologic separation would differ across the three hillslopes because of the these different physical conditions. One species sampled, lodgepole pine (Pinus contorta), is "isohydric"; stomatal conductance is regulated such that leaf water potential declines to a relatively high set point value during daily transpiration. The other two species, Engelmann spruce (Picea engelmannia) and sub-alpine fir (Abies laziocarpa) are "anisohydric", in that they allow daily minimum values of leaf water potential to vary and drop to values below that sustained by lodgepole pine. We predicted that ecohydrologic separation would be expressed to a greater degree on comparatively dry hillslopes and in species with anisohydric stomatal regulation. Quantifying and understanding such patterns of ecohydrological separation is important for

  13. Development of partial rock veneers by root throw in a subalpine setting (United States)

    Osterkamp, W.R.; Toy, T.J.; Lenart, M.T.


    Rock veneers stabilize hillslope surfaces, occur especially in areas of immature soil, and form through a variety of process sets that includes root throw. Near Westcliffe, Colorado, USA, data were collected from a 20 ?? 500 m transect on the east slope of the Sangre de Cristo Mountains. Ages of pit/mound complexes with rock fragments exposed at the surface by root throw ranged from recent (freshly toppled tree) to unknown (complete tree decay). Calculations based on dimensions of the pit/mound complexes, estimated time of free topppling, sizes of exposed rock fragments, and percentage rock covers at pit/mound complexes, as well as within the transect area, indicate that recent rates of root throw have resulted in only partial rock veneering since late Pleistocene deglaciation. Weathering of rock fragments prevent development of an extensive rock veneer and causes a balance, achieved within an estimated 700 years, between the rates of rock-fragment exposure by root throw and clast disintegration by chemical reduction. The estimated rate of rock-fragment reduction accounts for part of the fluvial sediment yields observed for forested subalpine areas of western North America. Copyright ?? 2005 John Wiley & Sons, Ltd.

  14. Effects of aerially applied mexacarbate on western spruce budworm larvae and their parasites in Montana (United States)

    Carroll B. Williams; Patrick J. Shea; Mark D. McGregor


    In tests on the Bitterroot National Forest, Montana, in 1965 and 1966, mexacarbate, aerially applied at the rate of 0.15 lb a.i./gal/acre (68.04 g a.iJ3.785 1/0.404 ha), killed about 90 percent of the western spruce budworm (Choristoneura occidentalis Freeman) populations. More parasitized budworm larvae survived treatments than nonparasitized.

  15. Modeling tree growth and stable isotope ratios of white spruce in western Alaska. (United States)

    Boucher, Etienne; Andreu-Hayles, Laia; Field, Robert; Oelkers, Rose; D'Arrigo, Rosanne


    Summer temperatures are assumed to exert a dominant control on physiological processes driving forest productivity in interior Alaska. However, despite the recent warming of the last few decades, numerous lines of evidence indicate that the enhancing effect of summer temperatures on high latitude forest populations has been weakening. First, satellite-derived indices of photosynthetic activity, such as the Normalized-Difference Vegetation Index (NDVI, 1982-2005), show overall declines in productivity in the interior boreal forests. Second, some white spruce tree ring series strongly diverge from summer temperatures during the second half of the 20th century, indicating a persistent loss of temperature sensitivity of tree ring proxies. Thus, the physiological response of treeline forests to ongoing climate change cannot be accurately predicted, especially from correlation analysis. Here, we make use of a process-based dendroecological model (MAIDENiso) to elucidate the complex linkages between global warming and increases in atmospheric CO2 concentration [CO2] with the response of treeline white spruce stands in interior Alaska (Seward). In order to fully capture the array of processes controlling tree growth in the area, multiple physiological indicators of white spruce productivity are used as target variables: NDVI images, ring widths (RW), maximum density (MXD) and newly measured carbon and oxygen stable isotope ratios from ring cellulose. Based on these data, we highlight the processes and mechanisms responsible for the apparent loss of sensitivity of white spruce trees to recent climate warming and [CO2] increase in order to elucidate the sensitivity and vulnerability of these trees to climate change.

  16. Phloeophagous and predaceous insects responding to synthetic pheromones of bark beetles inhabiting white spruce stands in the Great Lakes region. (United States)

    Haberkern, Kirsten E; Raffa, Kenneth F


    Tree killing and saprophytic bark beetles exert important ecological and economic roles in North American spruce forests. Chemical signaling among bark beetles, and responses by associate insects such as predators and competitors, have significant effects on the population dynamics and ecology of this community. Synthetic pheromones of primary (tree killing) and secondary (saprophytic) bark beetle species and blank controls were tested using multiple funnel and lower stem flight traps in white spruce forests in Wisconsin, Michigan, and Minnesota. Six phloeophagous and four predaceous species were collected with significant attraction by the bark beetles Dryocoetes affaber, Dryocoetes autographus, and Polygraphus rufipennis, and the predatory checkered beetles (Coleoptera: Cleridae) Thanasimus dubius and Enoclerus nigrifrons. In general, trap catches to synthetic lures resembled the species composition obtained by felling trees and collecting emerging beetles in a companion study, although several species showed differing trends. Some cross attraction occurred among bark beetles and between bark beetles and predatory beetles. For example, P. rufipennis was abundant in traps baited with Dryocoetes spp. pheromones. Thanasimus dubius and E. nigrifrons were collected in significant numbers in traps baited with the pheromone of the spruce beetle (Dendroctonus rufipennis), frontalin plus a-pinene. This is a new observation for E. nigrifrons. Attraction of T. dubius to the pheromones of at least three bark beetle species in the Great Lakes region, as well as to several southern and western species, reflects its role as a habitat specialist and feeding generalist. Several other important predators and competitors commonly obtained in pine forests in this region were not obtained in these spruce stands, either in response to synthetic pheromones of spruce colonizing beetles, or in host material colonized by these beetles. Potential differences in predator prey dynamics

  17. NPP Boreal Forest: Flakaliden, Sweden, 1986-1996, R1 (United States)

    National Aeronautics and Space Administration — This data set contains three files (.txt format) for an established 8.25 ha boreal forest dominated by Norway spruce, Picea abies, at Flakaliden (64.12 N 19.45 E) in...

  18. Timber productivity of seven forest ecosystems in southeastern Alaska. (United States)

    Willem W.S. van Hees


    Observations of growth on Alaska-cedar (Chamaecyparis nootkatensis), mountain hemlock (Tsuga mertensiana), Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and western redcedar (Thuja plicata) on seven forest ecosystems in southeastern Alaska...

  19. An Assessment of European Spruce Bark Beetle Infestation Using WorldView-2 Satellite Data (United States)

    Filchev, L.


    During the past three decades the spectral responses of declining forest health due to pest infestations as well as various methods for detection of trees' health status have been extensively studied. A set of narrow-band and broad-band Vegetation Indices (VIs) have been developed to assess the changes in the vegetation reflectance. The main objective of the study is to assess the damages caused by European Spruce Bark Beetle (Ips typographus L.) infestation in 'Bistrishko Branishte' UNESCO Man And Biosphere (MAB) reserve using WorldView-2 satellite data. The analysis was performed on Norway spruce (Picea abies) forest using the VIs indicative for forest stress: NDVI, SR, EVI, ARVI, CRI, CSc, and ARI. By applying density slice on the VIs, the main regions for stressed vegetation have been delineat ed. The CSc has been found to perform better in detecting the pattern of stressed spruce trees compared to ARI. The area affected by Ips typographus was determined by CSc index to 5.97% (0.373 km2) of the study area.

  20. The relationship between potential solar radiation and spruce bark beetle catches in pheromone traps

    Directory of Open Access Journals (Sweden)

    Pavel Mezei


    Full Text Available We analysed the relationship between the amount of potential solarradiation and spruce bark beetle Ips typographus (L. catches in pheromone traps in an unmanaged nature reserve in the Carpathians (middle Slovakia region, from 2006 through 2009. This relationship was analysed under outbreak conditions. The number of traps varied in different years from 70 to 92. The traps were installed in spruce-forest-dominated stands affected by a windstorm in 2004. A GPS device was used to mark the position of the pheromone traps. The potential solar radiation was calculated with GIS tools for three different time periods in each year:with entire year, for main flight season of the spruce bark beetle and the spring swarming period. The relationship between the amount of potential solar radiation and the spruce bark beetle catches was statistically significant for each year and each time period except for the spring swarming in 2007, when the pheromone traps were not set up on time.

  1. The relationship between potential solar radiation and spruce bark beetle catches in pheromone traps

    Directory of Open Access Journals (Sweden)

    Pavel Mezei


    Full Text Available We analysed the relationship between the amount of potential solar radiation and spruce bark beetleIps typographus (L. catches in pheromone traps in an unmanaged nature reserve in the Carpathians (middle Slovakia region, from 2006 through 2009. This relationship was analysed under outbreak conditions. The number of traps varied in different years from 70 to 92. The traps were installed in spruce-forest-dominated stands affected by a windstorm in 2004. A GPS device was used to mark the position of the pheromone traps. The potential solar radiation was calculated with GIS tools for three different time periods in each year: with entire year, for main flight season of the spruce bark beetle and the spring swarming period. The relationship between the amount of potential solar radiation and the spruce bark beetle catches was statistically significant for each year and each time period except for the spring warming in 2007, when the pheromone traps were not set up on time. 

  2. 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


    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.

  3. Comparative phytosocioogical investigation of subalpine alder thickets in southwestern Alaska and the North Pacific (United States)

    US Fish and Wildlife Service, Department of the Interior — We present the first vegetation analysis of subalpine alder (Alnus viridis) thickets in southwestern Alaska. The data are primarily from mesic, hilly and mountainous...

  4. Comparative study of long-term water uptake of Norway spruce and Douglas-fir in Moravian upland

    Directory of Open Access Journals (Sweden)

    Nadezhdina Nadezhda


    Full Text Available Long-term water uptake of Douglas-fir and Norway spruce trees, growing in condition of Moravian upland, was studied with aim of comparing sap flow in small roots with flow in stems. Sap flow was measured by the heat field deformation method using multi-point sensors for stems and single-point sensors for roots. Differences between species were found in relationships between sap flow in tree stems and water uptake by roots, suggesting that Douglas-fir is able to take water from deeper soil more efficiently than spruce. This allows Douglas-fir to transpire more water especially during drought and grow faster than spruce. These biological features should be taken into account for future forest species compositions because they may have impact on both, forestry and hydrology.

  5. Films from Glyoxal-Crosslinked Spruce Galactoglucomannans Plasticized with Sorbitol

    Directory of Open Access Journals (Sweden)

    Kirsi S. Mikkonen


    Full Text Available Films were prepared from a renewable and biodegradable forest biorefinery product, spruce O-acetyl-galactoglucomannans (GGMs, crosslinked with glyoxal. For the first time, cohesive and self-standing films were obtained from GGM without the addition of polyol plasticizer. In addition, glyoxal-crosslinked films were prepared using sorbitol at 10, 20, 30, and 40% (wt.-% of GGM. Glyoxal clearly strengthened the GGM matrix, as detected by tensile testing and dynamic mechanical analysis. The elongation at break of films slightly increased, and Young's modulus decreased with increasing sorbitol content. Interestingly, the tensile strength of films was constant with the increased plasticizer content. The effect of sorbitol on water sorption and water vapor permeability (WVP depended on relative humidity (RH. At low RH, the addition of sorbitol significantly decreased the WVP of films. The glyoxal-crosslinked GGM films containing 20% sorbitol exhibited the lowest oxygen permeability (OP and WVP of the studied films and showed satisfactory mechanical performance.

  6. A Long-term Forest Fertilization Experiment to Understand Ecosystem Responses to Atmospheric Nitrogen Deposition (United States)

    Baron, J.; Advani, S. M.; Allen, J.; Boot, C.; Denef, K.; Denning, S.; Hall, E.; Moore, J. C.; Reuth, H.; Ryan, M. G.; Shaw, E.


    Long-term field experiments can reveal changes in ecosystem processes that may not be evident in short-term studies. Short-term measurements or experiments may have narrower objectives or unrealistic treatments in order to see a change, whereas long-term studies can reveal complex interactions that take longer to manifest. We report results from a long-term experiment (1996 to present) in subalpine forests to simulate the consequences of sustained atmospheric nitrogen (N) deposition. Loch Vale watershed in Rocky Mountain National Park, the location of the experiment, has received an order of magnitude greater atmospheric N deposition than estimated background since mid-20th Century. Augmenting that, in 1996 we began adding 25 kg NH4NO3 ha-1 yr-1 to three 30m x 30m old-growth Engelmann spruce and subalpine fir plots. Treated stands were matched by nearby controls. N addition caused rapid leaching of nitrate and cations from soils, and increased N mineralization and nitrification rates. These observations in the fertilized plots have been sustained over time. Soluble aluminum concentrations do not differ significantly between fertilized and control plots, but treated soils are now markedly more acidic (pH of 4.7) than original soil and controls (pH of 5.1); further acidification might increase aluminum leaching. Effects on soil carbon were complex, mediated by reductions in total microbial biomass, decreases in arbuscular mychorrizal and saprotropic fungi, and increased potential rates of N enzyme degrading activities. Initial soil C:N of 24 was lower than similar soils in low N deposition stands (C:N of 36). The C:N declined to 22 with treatment. Fertilized plots lost 11% soil C, but the mechanism is unclear. We did not measure changes in C inputs from litter, microbial biomass, or plant uptake, but there was no change in summer CO2 flux, measured in 2003, 2004, and 2014. Leaching of DOC from fertilized plots was elevated throughout the experiment, providing one


    Directory of Open Access Journals (Sweden)

    Jacek Sosnowski Sosnowski


    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.

  8. Declining Bark Beetle Densities (Ips typographus, Coleoptera: Scolytinae from Infested Norway Spruce Stands and Possible Implications for Management

    Directory of Open Access Journals (Sweden)

    Alexander Angst


    Full Text Available The eight-toothed spruce bark beetle (Ips typographus is the most serious insect pest in Central European forests. During the past two decades, extreme meteorological events and subsequent beetle infestations have killed millions of cubic meters of standing spruce trees. Not all the infested stands could be cleared in time, and priorities in management had to be set. Natural or man-made buffer zones of about 500 meters in width are frequently defined to separate differently managed stands in Central Europe. While the buffer zones seem to be effective in most of the cases, their impact has not been studied in detail. Beetle densities were therefore assessed in three case studies using pheromone traps along transects, leading from infested stands into spruce-free buffer zones. The results of the trap catches allow an estimation of the buffer zone influence on densities and the dispersal of Ips typographus. Beetle densities were found to decrease rapidly with increasing distance from the infested spruce stands. The trap catches were below high-risk thresholds within a few hundred meters of the infested stands. The decrease in catches was more pronounced in open land and in an urban area than in a broadleaf stand. Designed buffer zones of 500 m width without spruce can therefore very probably help to reduce densities of spreading beetles.

  9. Old lower stem bark lesions apparently caused by unsuccessful spruce beetle attacks still evident on live spruce trees years later (United States)

    John S. Hard; Ken P. Zogas


    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. (United States)

    Edward H. Holsten; Richard A. Werner


    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. Structure and resilience of fungal communities in Alaskan boreal forest soils (United States)

    D. Lee Taylor; Ian C. Herriott; Kelsie E. Stone; Jack W. McFarland; Michael G. Booth; Mary Beth. Leigh


    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...

  12. Assessment of Forest Management in Protected Areas Based on Multidisciplinary Research

    Directory of Open Access Journals (Sweden)

    Ivo Machar


    Full Text Available The remnants of primeval Norway spruce forests in the European temperate zone are crucial for maintaining forest biodiversity in high mountain landscapes. This paper presents results of a multidisciplinary research and evaluation project on the management practices for mountain spruce forests in the Natura 2000 site (National Nature Reserve Serak-Keprnik in the Hruby Jesenik Mountains, the Czech Republic. Results are based on combining research on the historical development of the forest ecosystem and predictions of future dynamics using a forest growth simulation model. The presented results show that a non-intervention management strategy for mountain spruce forest in the next 50 years complies with the Natura 2000 requirement to maintain the existing character of the forest habitat. Thus, the results indicate that the current management plan for the spruce forests does not require significant corrections in the context of its conservation goals (i.e., maintaining biodiversity and current character of the forest ecosystem dominated by Norway spruce. The results of this study suggest that combining the knowledge of historical development with forest inventory data using forest growth simulation represents a suitable support tool for the assessment of management practices for forest habitats in protected areas.

  13. Effect of fungus Heterobasidion Annosum (FR bref. on fir and spruce dying in the region of the NP "Durmitor" and "Biogradska gora"

    Directory of Open Access Journals (Sweden)

    Anđelić Milosav


    Full Text Available Several adverse factors of abiotic and biotic nature affect the vitality and decline of spruce and fir in the region of NP "Durmitor" and NP "Biogradska Gora". The most significant adverse abiotic factor is air pollution. Among the adverse biotic factors, the most significant is by all means the parasitic fungus Heterobasidion annosum. The damage caused by this fungus is especially severe in spruce and fir stands in the region of the NP "Durmitor". The infection intensity is approximately the same in both species. The damage caused by H. annosum is greater in the forests of NP "Durmitor", than in the forests of NP "Biogradska Gora". This can be explained by the fact that spruce and fir stands on Durmitor were felled without maintaining the forest order. In the virgin forest reserve NP "Biogradska Gora" in the past there were no fellings, i.e. the impact of anthropogenic factors was excluded. Fungus H. annosum cannot be eliminated form spruce and fir stands on Durmitor, but the treatment of stumps (immediately after the sanitation felling with "Penofil" or "Borax" can check the velocity of its spread. In this way, the forest is given an opportunity to form more resistant populations through a long period by natural selection .

  14. Using stable water isotopes and borehole NMR to inform an ecohydrological model in a subalpine and upper montane catchment in the Rocky Mountains (United States)

    Millar, D.; Parsekian, A.; Mercer, J.; Speckman, H. N.; Beverly, D.; Ewers, B. E.; Mackay, D. S.


    Recent work using stable water isotopes has revealed that vegetation across a range of different biomes preferentially take up tightly bound soil water over more mobile pools. This so called two water worlds hypothesis (TWWH) has important implications for hydrological modeling efforts in ecosystems where it holds true, since few if any ecohydrological models incorporate this phenomenon. Further, in ecosystems where the TWWH is supported, information regarding the proportion of soil water in the bound and mobile pools is necessary to inform plant-soil water dynamics in models. In this study, we investigate which soil water pools are used by dominant vegetation in an upper montane and subalpine catchment in the Rocky Mountains of southern Wyoming, and use this information to inform the Terrestrial Regional Ecosystem Exchange Simulator (TREES). Within each catchment, we test the TWWH using stable water isotope analyses in an upland coniferous forest and an adjacent, downgradient groundwater-supported wetland. The proportion of soil water in each pool within each ecosystem was inferred from borehole nuclear magnetic resonance (NMR). These field data are being incorporated into TREES, by partitioning plant water uptake between bound and mobile pools. NMR analyses were conducted in all four ecosystems down to a depth of approximately 75 cm and revealed that while mid growing season soil water content was approximately two-fold higher in the subalpine forest versus that of the upper montane forest, the vast majority of soil water, 86% on average, existed in the bound pool in both ecosystems. Alternatively, soils in both wetlands were saturated throughout their profiles, with a majority of the soil water existing in the mobile pool, 63% on average. These initial findings highlight the importance of bound soil water pools in both upland forests, as opposed to the wetlands, which had an abundance of water in both pools.

  15. Chapter 6: Creating a basis for watershed management in high elevation forests (United States)

    Gerald J. Gottfried; Leonard F. DeBano; Peter F. Ffolliott


    Higher mountains and plateaus in the Central Arizona Highlands generally support southwestern mixed conifer forests, associated aspen and spruce-fir forests, and a small acreage of grasslands interspersed among the forested areas. Most of the major rivers in the region originate on headwater watersheds that support mixed conifer forests where annual precipitation,...

  16. Multi-sensor data fusion for estimating forest species composition and abundance in northern Minnesota (United States)

    Peter P. Wolter; Phillip A. Townsend


    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...

  17. 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.


    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...... or downward flux was observed. The results from a laboratory intercomparison made in Spain deviated by maximum 7%. The flux measured at the two sites exhibited a strong diurnal variation with maximum in the afternoon and minimum in the morning hours and evenings. The applied REA system is new in its design...... 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....

  18. The content of cytokinins in Norway spruce needles at the OTC site - preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Doumas, P.; Daoudi, E.H.; Gautrat, M.P.; Schwartzenberg, K. v.; Bonnet-Massimbert, M. [Centre de Recherche d`Orleans, Station d`Amelioration des Arbres Forestiers, 45 - Ardon (France)


    The relationship of air pollution factors to observed forest decline can be investigated from different viewpoints incorporating physiological and biochemical changes. A hormone imbalance can be the result of growth disturbances, as a direct or indirect effect of air pollution. To prove this hypothesis, within an air pollution exclusion experiment in Open Top Chambers at the Edelmannshof site, the variations in the content of different cytokinins were analyzed in Norway spruce needles at various times during annual growth. The first approach adapted the cytokinin extraction and purification method, which is classically used in the laboratory. A second approach presented a one-year time course of the cytokinin content in one-year-old Norway spruce needles. (orig./MG)

  19. Rapid recovery of stem increment in Norway spruce at reduced SO2 levels in the Harz Mountains, Germany. (United States)

    Hauck, Markus; Zimmermann, Jorma; Jacob, Mascha; Dulamsuren, Choimaa; Bade, Claudia; Ahrends, Bernd; Leuschner, Christoph


    Tree-ring width of Picea abies was studied along an altitudinal gradient in the Harz Mountains, Germany, in an area heavily affected by SO(2)-related forest decline in the second half of the 20th century. Spruce trees of exposed high-elevation forests had earlier been shown to have reduced radial growth at high atmospheric SO(2) levels. After the recent reduction of the SO(2) load due to clean air acts, we tested the hypothesis that stem growth recovered rapidly from the SO(2) impact. Our results from two formerly damaged high-elevation spruce stands support this hypothesis suggesting that the former SO(2)-related spruce decline was primarily due to foliar damage and not to soil acidification, as the deacidification of the (still acidic) soil would cause a slow growth response. Increasing temperatures and deposited N accumulated in the topsoil are likely additional growth-promoting factors of spruce at high elevations after the shortfall of SO(2) pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Effect of bark beetle (Ips typographus L.) attack on bark VOC emissions of Norway spruce (Picea abies Karst.) trees (United States)

    Ghimire, Rajendra P.; Kivimäenpää, Minna; Blomqvist, Minna; Holopainen, Toini; Lyytikäinen-Saarenmaa, Päivi; Holopainen, Jarmo K.


    Climate warming driven storms are evident causes for an outbreak of the European spruce bark beetle (Ips typographus L.) resulting in the serious destruction of mature Norway spruce (Picea abies Karst.) forests in northern Europe. Conifer species are major sources of biogenic volatile organic compounds (BVOCs) in the boreal zone. Climate relevant BVOC emissions are expected to increase when conifer trees defend against bark beetle attack by monoterpene (MT)-rich resin flow. In this study, BVOC emission rates from the bark surface of beetle-attacked and non-attacked spruce trees were measured from two outbreak areas, Iitti and Lahti in southern Finland, and from one control site at Kuopio in central Finland. Beetle attack increased emissions of total MTs 20-fold at Iitti compared to Kuopio, but decreased the emissions of several sesquiterpenes (SQTs) at Iitti. At the Lahti site, the emission rate of α-pinene was positively correlated with mean trap catch of bark beetles. The responsive individual MTs were tricyclene, α-pinene, camphene, myrcene, limonene, 1,8-cineole and bornyl acetate in both of the outbreak areas. Our results suggest that bark beetle outbreaks affect local BVOC emissions from conifer forests dominated by Norway spruce. Therefore, the impacts of insect outbreaks are worth of consideration to global BVOC emission models.

  1. Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany. (United States)

    Vitali, Valentina; Büntgen, Ulf; Bauhus, Jürgen


    Improving our understanding of the potential of forest adaptation is an urgent task in the light of predicted climate change. Long-term alternatives for susceptible yet economically important tree species such as Norway spruce (Picea abies) are required, if the frequency and intensity of summer droughts will continue to increase. Although Silver fir (Abies alba) and Douglas fir (Pseudotsuga menziesii) have both been described as drought-tolerant species, our understanding of their growth responses to drought extremes is still limited. Here, we use a dendroecological approach to assess the resistance, resilience, and recovery of these important central Europe to conifer species the exceptional droughts in 1976 and 2003. A total of 270 trees per species were sampled in 18 managed mixed-species stands along an altitudinal gradient (400-1200 m a.s.l.) at the western slopes of the southern and central Black Forest in southwest Germany. While radial growth in all species responded similarly to the 1976 drought, Norway spruce was least resistant and resilient to the 2003 summer drought. Silver fir showed the overall highest resistance to drought, similarly to Douglas fir, which exhibited the widest growth rings. Silver fir trees from lower elevations were more drought prone than trees at higher elevations. Douglas fir and Norway spruce, however, revealed lower drought resilience at higher altitudes. Although the 1976 and 2003 drought extremes were quite different, Douglas fir maintained consistently the highest radial growth. Although our study did not examine population-level responses, it clearly indicates that Silver fir and Douglas fir are generally more resistant and resilient to previous drought extremes and are therefore suitable alternatives to Norway spruce; Silver fir more so at higher altitudes. Cultivating these species instead of Norway spruce will contribute to maintaining a high level of productivity across many Central European mountain forests under

  2. Climate-diameter growth relationships of black spruce and jack pine trees in boreal Ontario, Canada. (United States)

    Subedi, Nirmal; Sharma, Mahadev


    To predict the long-term effects of climate change - global warming and changes in precipitation - on the diameter (radial) growth of jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) trees in boreal Ontario, we modified an existing diameter growth model to include climate variables. Diameter chronologies of 927 jack pine and 1173 black spruce trees, growing in the area from 47°N to 50°N and 80°W to 92°W, were used to develop diameter growth models in a nonlinear mixed-effects approach. Our results showed that the variables long-term average of mean growing season temperature, precipitation during wettest quarter, and total precipitation during growing season were significant (alpha = 0.05) in explaining variation in diameter growth of the sample trees. Model results indicated that higher temperatures during the growing season would increase the diameter growth of jack pine trees, but decrease that of black spruce trees. More precipitation during the wettest quarter would favor the diameter growth of both species. On the other hand, a wetter growing season, which may decrease radiation inputs, increase nutrient leaching, and reduce the decomposition rate, would reduce the diameter growth of both species. Moreover, our results indicated that future (2041-2070) diameter growth rate may differ from current (1971-2000) growth rates for both species, with conditions being more favorable for jack pine than black spruce trees. Expected future changes in the growth rate of boreal trees need to be considered in forest management decisions. We recommend that knowledge of climate-growth relationships, as represented by models, be combined with learning from adaptive management to reduce the risks and uncertainties associated with forest management decisions. © 2012 Blackwell Publishing Ltd.

  3. Ozone concentration characteristics at a high-elevation forest site (United States)

    G. Wooldridge; K. Zeller; R. Musselman


    Atmospheric ozone concentrations have been monitored at a subalpine forest ecosystem site, 3180m above mean sea level (msl), and at a 2680m msl forest-steppe ecotone site 15km to the southeast. Ozone concentrations were monitored at three heights above the ground on a 30m tower at the higher elevation site, and on a 10m tower in a large meadow downwind of this site....

  4. Hydrologic flow path development varies by aspect during spring snowmelt in complex subalpine terrain (United States)

    Webb, Ryan W.; Fassnacht, Steven R.; Gooseff, Michael N.


    In many mountainous regions around the world, snow and soil moisture are key components of the hydrologic cycle. Preferential flow paths of snowmelt water through snow have been known to occur for years with few studies observing the effect on soil moisture. In this study, statistical analysis of the topographical and hydrological controls on the spatiotemporal variability of snow water equivalent (SWE) and soil moisture during snowmelt was undertaken at a subalpine forested setting with north, south, and flat aspects as a seasonally persistent snowpack melts. We investigated if evidence of preferential flow paths in snow can be observed and the effect on soil moisture through measurements of snow water equivalent and near-surface soil moisture, observing how SWE and near-surface soil moisture vary on hillslopes relative to the toes of hillslopes and flat areas. We then compared snowmelt infiltration beyond the near-surface soil between flat and sloping terrain during the entire snowmelt season using soil moisture sensor profiles. This study was conducted during varying snowmelt seasons representing above-normal, relatively normal, and below-normal snow seasons in northern Colorado. Evidence is presented of preferential meltwater flow paths at the snow-soil interface on the north-facing slope causing increases in SWE downslope and less infiltration into the soil at 20 cm depth; less association is observed in the near-surface soil moisture (top 7 cm). We present a conceptualization of the meltwater flow paths that develop based on slope aspect and soil properties. The resulting flow paths are shown to divert at least 4 % of snowmelt laterally, accumulating along the length of the slope, to increase the snow water equivalent by as much as 170 % at the base of a north-facing hillslope. Results from this study show that snow acts as an extension of the vadose zone during spring snowmelt and future hydrologic investigations will benefit from studying the snow and soil

  5. Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes (United States)

    Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick


    Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

  6. Calcium induces long-term legacy effects in a subalpine ecosystem.

    Directory of Open Access Journals (Sweden)

    Urs Schaffner

    Full Text Available Human activities have transformed a significant proportion of the world's land surface, with profound effects on ecosystem processes. Soil applications of macronutrients such as nitrate, phosphorus, potassium or calcium are routinely used in the management of croplands, grasslands and forests to improve plant health or increase productivity. However, while the effects of continuous fertilization and liming on terrestrial ecosystems are well documented, remarkably little is known about the legacy effect of historical fertilization and liming events in terrestrial ecosystems and of the mechanisms involved. Here, we show that more than 70 years after the last application of lime on a subalpine grassland, all major soil and plant calcium pools were still significantly larger in limed than in unlimed plots, and that the resulting shift in the soil calcium/aluminium ratio continues to affect ecosystem services such as primary production. The difference in the calcium content of the vegetation and the topmost 10 cm of the soil in limed vs. unlimed plots amounts to approximately 19.5 g m(-2, equivalent to 16.3% of the amount that was added to the plots some 70 years ago. In contrast, plots that were treated with nitrogen-phosphorus-potassium fertilizer in the 1930s did not differ from unfertilized plots in any of the soil and vegetation characteristics measured. Our findings suggest that the long-term legacy effect of historical liming is due to long-term storage of added calcium in stable soil pools, rather than a general increase in nutrient availability. Our results demonstrate that single applications of calcium in its carbonated form can profoundly and persistently alter ecosystem processes and services in mountain ecosystems.

  7. Photosynthetic capacity of red spruce during winter (United States)

    P.G. Schaberg; J.B. Shane; P.F. Cali; J.R. Donnelly; G.R. Strimbeck


    We measured the photosynthetic capacity (Pmax) of plantation-grown red spruce (Picea rubens Sarg.) during two winter seasons (1993-94 and 1994-95) and monitored field photosynthesis of these trees during one winter (1993-94). We also measured Pmax for mature montane trees from January through May 1995....

  8. Root system in declining forests

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, F.H.


    Trees with obligate ectomycorrhiza are more sensitive to environmental stress than those without ectomycorrhiza or with facultative ectomycorrhiza. With spruce seedlings growing in humus material from a declining spruce forest an experimental proof was given, that reduction of the mineral nitrogen content by adding sawdust to the rooting substrate increases the share of root tips converted to ectomycorrhizas. A close correlation has been found between the mycorrhiza frequency and the number of root tips. This means, that the ramification of a root system is the more intense the better the conditions for mycorrhizal development are.

  9. Survival of Norway spruce remains higher in mixed stands under a dryer and warmer climate. (United States)

    Neuner, Susanne; Albrecht, Axel; Cullmann, Dominik; Engels, Friedrich; Griess, Verena C; Hahn, W Andreas; Hanewinkel, Marc; Härtl, Fabian; Kölling, Christian; Staupendahl, Kai; Knoke, Thomas


    Shifts in tree species distributions caused by climatic change are expected to cause severe losses in the economic value of European forestland. However, this projection disregards potential adaptation options such as tree species conversion, shorter production periods, or establishment of mixed species forests. The effect of tree species mixture has, as yet, not been quantitatively investigated for its potential to mitigate future increases in production risks. For the first time, we use survival time analysis to assess the effects of climate, species mixture and soil condition on survival probabilities for Norway spruce and European beech. Accelerated Failure Time (AFT) models based on an extensive dataset of almost 65,000 trees from the European Forest Damage Survey (FDS)--part of the European-wide Level I monitoring network--predicted a 24% decrease in survival probability for Norway spruce in pure stands at age 120 when unfavorable changes in climate conditions were assumed. Increasing species admixture greatly reduced the negative effects of unfavorable climate conditions, resulting in a decline in survival probabilities of only 7%. We conclude that future studies of forest management under climate change as well as forest policy measures need to take this, as yet unconsidered, strongly advantageous effect of tree species mixture into account. © 2014 John Wiley & Sons Ltd.

  10. Climate, geography, and tree establishment in subalpine meadows of the Olympic Mountains, Washington, USA (United States)

    Woodward, Andrea; Schreiner, Edward G.; Silsbee, D.G.


    Noticeable changes in vegetation distribution have occurred in the Pacific Northwest during the last century as trees have established in some subalpine meadows. To study the relationship of this process to climate, recently established trees were aged in six subalpine meadows in the Olympic Mountains, Washington. The sites represent three points along a steep precipitation gradient. Subalpine fir (Abies lasiocarpa) has been establishing at the dry end of the gradient, mountain hemlock (Tsuga mertensiana) at the wet end, and both species in the center. Establishment patterns were compared with deviations from the century-long average for these weather variables: winter precipitation, Palmer Drought Severity Index, and winter, October, and May temperatures. Results show that establishment occurred in dry areas when weather conditions were wetter than average, and in wet areas under drier than average conditions. Establishment at central sites did not show consistent relationships with climate. If future climatic conditions continue to warm, establishment of subalpine fir in subalpine meadows in dry areas may cease and mountain hemlock may resume in wet areas.

  11. Spruce bark beetle in Sumava NP: A precedent case of EU Wilderness Protection, the role of NGOs and the public in wilderness protection (United States)

    Jaromir Blaha; Vojtech Kotecky


    Sumava National Park, in the Czech Republic, is, along with the adjacent Bayerischer Wald NP in Germany, one of the largest wilderness areas in Western and Central Europe. Mountain spruce forests here have been heavily influenced by natural disturbances. Following years of debate about conservation management in the national park, logging operations on the Czech side...

  12. Shoot water relations of mature black spruce families displaying a genotype x environment interaction in growth rate. II. Temporal trends and response to varying soil water conditions (United States)

    John E. Major; Kurt H. Johnsen


    Pressure-volume curves and shoot water potentials were determined for black spruce (Picea mariana (Mill.) BSP) trees from four full-sib families at the Petawawa Research Forest, Ontario, Canada. Trees were sampled from a dry site in 1992 and from the dry site and a wet site in 1993. Modulus of elasticity (e ), osmotic potential at...

  13. Historical patterns of western spruce budworm and Douglas-fir tussock moth outbreaks in the northern Blue Mountains, Oregon, since A.D. 1700. (United States)

    Thomas Swetnam; Boyd E. Wickman; H. Gene Paul; Christopher H. Baisan


    Dendroecology methods were used to reconstruct a three-century history of western spruce budworm and Douglas-fir tussock moth outbreaks in the Blue Mountains of northeastern Oregon. Comparisons of 20th century Forest Service documentary records and host and nonhost tree-ring width chronologies provided an objective basis for distinguishing climatic effects from insect-...

  14. A multi-proxy record of hydroclimate, vegetation, fire, and post-settlement impacts for a subalpine plateau, Central Rocky Mountains U.S.A (United States)

    Anderson, Lesleigh; Brunelle, Andrea; Thompson, Robert S.


    Apparent changes in vegetation distribution, fire, and other disturbance regimes throughout western North America have prompted investigations of the relative importance of human activities and climate change as potential causal mechanisms. Assessing the effects of Euro-American settlement is difficult because climate changes occur on multi-decadal to centennial time scales and require longer time perspectives than historic observations can provide. Here, we report vegetation and environmental changes over the past ~13,000 years as recorded in a sediment record from Bison Lake, a subalpine lake on a high plateau in northwestern Colorado. Results are based on multiple independent proxies, which include pollen, charcoal, and elemental geochemistry, and are compared with previously reported interpretations of hydroclimatic changes from oxygen isotope ratios. The pollen data indicate a slowly changing vegetation sequence from sagebrush steppe during the late glacial to coniferous forest through the late Holocene. The most dramatic vegetation changes of the Holocene occurred during the ‘Medieval Climate Anomaly’ (MCA) and ‘Little Ice Age’ (LIA) with rapid replacement of conifer forest by grassland followed by an equally rapid return to conifer forest. Late Holocene vegetation responses are mirrored by changes in fire, lake biological productivity, and watershed erosion. These combined records indicate that subsequent disturbance related to Euro-American settlement, although perhaps significant, had acted upon a landscape that was already responding to MCA-LIA hydroclimatic change. Results document both rapid and long-term subalpine grassland ecosystem dynamics driven by agents of change that can be anticipated in the future and simulated by ecosystem models.

  15. Rainfall interception and spatial variability of throughfall in spruce stand

    Directory of Open Access Journals (Sweden)

    Dohnal Michal


    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.

  16. ISLSCP II Carbon Dioxide Flux at Harvard Forest and Northern BOREAS Sites (United States)

    National Aeronautics and Space Administration — Carbon dioxide flux and meteorological data for the Harvard Forest, MA (1992-95) and BOREAS Northern Study Area, Old Black Spruce (Alberta, Canada; 1994-95) FLUXNET...

  17. ISLSCP II Carbon Dioxide Flux at Harvard Forest and Northern BOREAS Sites (United States)

    National Aeronautics and Space Administration — ABSTRACT: Carbon dioxide flux and meteorological data for the Harvard Forest, MA (1992-95) and BOREAS Northern Study Area, Old Black Spruce (Alberta, Canada;...

  18. Growth trends of beech and Norway spruce in Switzerland: The role of nitrogen deposition, ozone, mineral nutrition and climate. (United States)

    Braun, Sabine; Schindler, Christian; Rihm, Beat


    Understanding the effects of nitrogen deposition, ozone and climate on tree growth is important for planning sustainable forest management also in the future. The complex interplay of all these factors cannot be covered by experiments. Here we use observational data of mature forests for studying associations of various biotic and abiotic factors with tree growth. A 30year time series on basal area increment of Fagus sylvatica L. and Picea abies Karst. in Switzerland was analyzed to evaluate the development in relation to a variety of predictors. Basal area increment of Fagus sylvatica has clearly decreased during the observation period. For Picea abies no trend was observed. N deposition of more than 26 (beech) or 20-22kgNha(-1)year(-1) (Norway spruce) was negatively related with basal area increment, in beech stronger than in Norway spruce. High N deposition loads and low foliar K concentrations in Fagus were correlated with increased drought sensitivity. High air temperatures in winter were negatively related with basal area increment in Norway spruce in general and in beech at high N:Mg ratio or high N deposition while on an average the relation was positive in beech. Fructification in beech was negatively related to basal area increment. The increase of fructification observed during the last decades contributed thus to the growth decrease. Ozone flux was significantly and negatively correlated with basal area increment both in beech and Norway spruce. The results show clear non-linear effects of N deposition on stem increment of European beech and Norway spruce as well as strong interactions with climate which have contributed to the growth decrease in beech and may get more important in future. The results not only give suggestions for ecological processes but also show the potential of an integral evaluation of observational data. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The bud break process and its variation among local populations of boreal black spruce. (United States)

    Rossi, Sergio; Bousquet, Jean


    Phenology of local populations can exhibit adaptations to the current environmental conditions resulting from a close interaction between climate and genotype. The bud break process and its variations among populations were analyzed in greenhouse by monitoring the growth resumption in black spruce [Picea mariana (Mill.) BSP] seedlings originating from seeds of five stands across the closed boreal forest in Quebec, Canada. Bud break lasted 15 days and occurred earlier and quicker in northern provenances. Provenance explained between 10.2 and 32.3% of the variance in bud break, while the families accounted for a smaller but still significant part of the variance. The late occurrence of one phenological phase corresponded to a delayed occurrence of the others according to linear relationships. A causal model was proposed in the form of a chain of events with each phase of bud break being related to the previous and successive one, while no link was observed between non-adjacent phases. The adaptation of black spruce populations along the latitudinal gradient points toward a strategy based on rapid physiological processes triggered by temperature increase inducing high metabolic activity. The variation observed in bud break reflects an evolutionary trade-off between maximization of security and taking advantage of the short growing season. This work provides evidence of the phenological adaptations of black spruce to its local environmental conditions while retaining sizeable genetic diversity within populations. Because of the multigenic nature of phenology, this diversity should provide some raw material for adaptation to changing local environmental conditions.

  20. Evaluation of IRS-1C LISS-3 satellite data for Norway spruce defoliation assessment

    Energy Technology Data Exchange (ETDEWEB)

    Falkenstroem, H.


    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

  1. Occurrence and formation of chloroform at Danish forest sites

    DEFF Research Database (Denmark)

    Haselmann, K.F.; Ketola, R.A.; Laturnus, F.


    Ambient air and soil air of spruce forest, beech forest and grassland from Zealand, Denmark, were investigated for volatile chlorinated compounds by adsorbent tube sampling, thermodesorption, cryo-trapping and analysis by high-resolution gas chromatography with electron capture detection. The mean...... the initial soil air concentration after 38 h, while the concentrations of the other volatile chlorinated compounds investigated remained fairly constant. The observed chloroform concentration profiles and release rates may indicate a biogenic formation of chloroform in the upper soil layer of spruce forests......, whereas an anthropogenic origin is suggested for the other chlorinated compounds investigated. From the release study and concentration gradient measurements in the spruce forest soil, chloroform release to the atmosphere was calculated for northern temperate regions. The release was in the range...

  2. DTA Evaluation of Spruce Wood Degradation Process (United States)

    Hrušovský, Ivan; Rantuch, Peter; Martinka, Jozef; Dzíbelová, Simona


    The decomposition stages of spruce wood sawdust were analyzed by means of sequential differential calorimetry. Two stages of decomposition were identified and activation energy of one stage was calculated using the Kissinger method. The DTA was conducted by means of SEDEX safety calorimeter. Sample was analyzed under three heating rates of 10, 20 and 45 °C/h in temperature range from room temperature to 400 °C. The calculated activation energy for the last and most clear decomposition peak was 122.63 KJ/mol. The results are comparable with the data calculated by J.V. Rissanen et al., who calculated activation energy for Spruce hemicellulose as 120 KJ/mol.

  3. Taxonomy Icon Data: Sitka spruce [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Sitka spruce Picea sitchensis Picea_sitchensis_L.png Picea_sitchensis_NL.png Picea_sitchen...sis_S.png Picea_sitchensis_NS.png ...

  4. Forest and land inventory using ERTS imagery and aerial photography in the boreal forest region of Alberta, Canada (United States)

    Kirby, C. L.


    Satellite imagery and small-scale (1:120,000) infrared ektachrome aerial photography for the development of improved forest and land inventory techniques in the boreal forest region are presented to demonstrate spectral signatures and their application. The forest is predominately mixed, stands of white spruce and poplar, with some pure stands of black spruce, pine and large areas of poorly drained land with peat and sedge type muskegs. This work is part of coordinated program to evaluate ERTS imagery by the Canadian Forestry Service.

  5. Comparison of the Chemical Properties of Forest Soil from the Silesian Beskid, Poland

    Directory of Open Access Journals (Sweden)

    Maria Zołotajkin


    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.

  6. Throughfall deposition and canopy exchange processes along a vertical gradient within the canopy of beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst). (United States)

    Adriaenssens, Sandy; Hansen, Karin; Staelens, Jeroen; Wuyts, Karen; De Schrijver, An; Baeten, Lander; Boeckx, Pascal; Samson, Roeland; Verheyen, Kris


    To assess the impact of air pollution on forest ecosystems, the canopy is usually considered as a constant single layer in interaction with the atmosphere and incident rain, which could influence the measurement accuracy. In this study the variation of througfall deposition and derived dry deposition and canopy exchange were studied along a vertical gradient in the canopy of one European beech (Fagus sylvatica L.) tree and two Norway spruce (Picea abies (L.) Karst) trees. Throughfall and net throughfall deposition of all ions other than H(+) increased significantly with canopy depth in the middle and lower canopy of the beech tree and in the whole canopy of the spruce trees. Moreover, throughfall and net throughfall of all ions in the spruce canopy decreased with increasing distance to the trunk. Dry deposition occurred mainly in the upper canopy and was highest during the growing season for H(+), NH(4)(+), NO(3)(-) and highest during the dormant season for Na(+), Cl(-), SO(4)(2-) (beech and spruce) and K(+), Ca(2+) and Mg(2+) (spruce only). Canopy leaching of K(+), Ca(2+) and Mg(2+) was observed at all canopy levels and was higher for the beech tree compared to the spruce trees. Canopy uptake of inorganic nitrogen and H(+) occurred mainly in the upper canopy, although significant canopy uptake was found in the middle canopy as well. Canopy exchange was always higher during the growing season compared to the dormant season. This spatial and temporal variation indicates that biogeochemical deposition models would benefit from a multilayer approach for shade-tolerant tree species such as beech and spruce. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Nutrient status in soil of Ski runs in the sub-alpine belt of Uludag Mountain, Bursa, Turkey. (United States)

    Guleryuz, Gurcan; Kirmizi, Serap; Arslan, Hulya


    Large areas of land are disturbed in sensitive bio-diverse mountain environments by Skiruns. Restoration of vegetation on such disturbed mountain sites may be hampered by soil degradation but the severity and nature of the constraints is not well understood. This study was designed to compare the water holding and nutritional status of soil in three Ski runs which had different construction dates and disturbance levels, and the adjacent undisturbed site in the Abies bommuelleriana forest community in the sub-alpine belt of Uludag Mountain (Bithynian Olympus). The values of soil parameters were depressed in proportion to the disturbance level. Water holding capacity (WHC), total nitrogen (N), organic carbon (C) and calcium (Ca2+), magnesium (Mg2+) and potassium (K+) contents (mg kg(-1) dry weight) of soils in the Ski run which had the highest disturbance level were lower than that of the undisturbed adjacent sites. However the results indicated that the soil parameters were less degraded when secondary vegetation was growing on the disturbed areas.

  8. Linkages between grazing history and herbivore exclusion on decomposition rates in mineral soils of subalpine grasslands (United States)

    Alan G. Haynes; Martin Schutz; Nina Buchmann; Deborah S. Page-Dumroese; Matt D. Busse; Anita C. Risch


    Herbivore-driven changes to soil properties can influence the decomposition rate of organic material and therefore soil carbon cycling within grassland ecosystems. We investigated how aboveground foraging mammalian and invertebrate herbivores affect mineral soil decomposition rates and associated soil properties in two subalpine vegetation types (shortgrass and tall-...

  9. Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability (United States)

    Peggy E. Moore; Jan W. van Wagtendonk; Julie L. Yee; Mitchel P. McClaran; David N. Cole; Neil K. McDougald; Matthew L. Brooks


    Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate....

  10. Multiscale habitat relationships of snowshoe hares (Lepus americanus) in the mixed conifer landscape of the Northern Rockies, USA: Cross-scale effects of horizontal cover with implications for forest management. (United States)

    Holbrook, Joseph D; Squires, John R; Olson, Lucretia E; Lawrence, Rick L; Savage, Shannon L


    Snowshoe hares (Lepus americanus) are an ecologically important herbivore because they modify vegetation through browsing and serve as a prey resource for multiple predators. We implemented a multiscale approach to characterize habitat relationships for snowshoe hares across the mixed conifer landscape of the northern Rocky Mountains, USA. Our objectives were to (1) assess the relationship between horizontal cover and snowshoe hares, (2) estimate how forest metrics vary across the gradient of snowshoe hare use and horizontal cover, and (3) model and map snowshoe hare occupancy and intensity of use. Results indicated that both occupancy and intensity of use by snowshoe hares increased with horizontal cover and that the effect became stronger as intensity of use increased. This underscores the importance of dense horizontal cover to achieve high use, and likely density, of snowshoe hares. Forest structure in areas with high snowshoe hare use and horizontal cover was characterized as multistoried with dense canopy cover and medium-sized trees (e.g., 12.7-24.4 cm). The abundance of lodgepole pine (Pinus contorta) was associated with snowshoe hare use within a mixed conifer context, and the only species to increase in abundance with horizontal cover was Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa). Our landscape-level modeling produced similar patterns in that we observed a positive effect of lodgepole pine and horizontal cover on both occupancy and use by snowshoe hares, but we also observed a positive yet parabolic effect of snow depth on snowshoe hare occupancy. This work is among the first to characterize the multiscale habitat relationships of snowshoe hares across a mixed conifer landscape as well as to map their occupancy and intensity of use. Moreover, our results provide stand- and landscape-level insights that directly relate to management agencies, which aids in conservation efforts of snowshoe hares and their associated

  11. Comparison of Bt formulations against the spruce budworm (United States)

    Lew McCreery; Imants Millers; Dennis Souto; Bruce Francis


    The Passamaquoddy Indian Forestry Department treated 40,300 acres in Maine in 1983 using Bt to protect red spruce and eastern hemlock from spruce budworm damage. The post treatment evaluation indicated that the protection objectives were achieved. In cooperation between the Passamaquoddy Indian Forestry Department and two commercial Bt suppliers, Abbott Laboratories...

  12. Fertilization of black spruce or poor site peatland in Minnesota. (United States)

    David H. Alban; Richard F. Watt


    Fertilization of poor site black spruce on organic soil with various rates of nitrogen and phosphorus increased height and diameter growth from 2 to 4 times. The growth response declined with time but was still apparent 16 years after fertilization. Shrub biomass and coverage, and nutrient levels of spruce foliage were strongly affected by fertilization.

  13. Analyses of Great Smoky Mountain Red Spruce Tree Ring Data (United States)

    Paul C. van Deusen; [Editor


    Four different analyses of red spruce tree ring data from the Great Smoky Mountains are presented along with a description of the spruce/fir ecosystem.The analyses use several techniques including spatial analysis, fractals, spline detrending, and the Kalman filter.

  14. Fuel deposition rates of montane and subalpine conifers in the central Sierra Nevada, California, USA (United States)

    van Wagtendonk, J.W.; Moore, P.E.


    Fire managers and researchers need information on fuel deposition rates to estimate future changes in fuel bed characteristics, determine when forests transition to another fire behavior fuel model, estimate future changes in fuel bed characteristics, and parameterize and validate ecosystem process models. This information is lacking for many ecosystems including the Sierra Nevada in California, USA. We investigated fuel deposition rates and stand characteristics of seven montane and four subalpine conifers in the Sierra Nevada. We collected foliage, miscellaneous bark and crown fragments, cones, and woody fuel classes from four replicate plots each in four stem diameter size classes for each species, for a total of 176 sampling sites. We used these data to develop predictive equations for each fuel class and diameter size class of each species based on stem and crown characteristics. There were consistent species and diameter class differences in the annual amount of foliage and fragments deposited. Foliage deposition rates ranged from just over 50 g m-2 year-1 in small diameter mountain hemlock stands to ???300 g m-2 year-1 for the three largest diameter classes of giant sequoia. The deposition rate for most woody fuel classes increased from the smallest diameter class stands to the largest diameter class stands. Woody fuel deposition rates varied among species as well. The rates for the smallest woody fuels ranged from 0.8 g m-2 year-1 for small diameter stands of Jeffrey pine to 126.9 g m-2 year-1 for very large diameter stands of mountain hemlock. Crown height and live crown ratio were the best predictors of fuel deposition rates for most fuel classes and species. Both characteristics reflect the amount of crown biomass including foliage and woody fuels. Relationships established in this study allow predictions of fuel loads to be made on a stand basis for each of these species under current and possible future conditions. These predictions can be used to

  15. Modelling Forest Water Consumption in The Netherlands

    NARCIS (Netherlands)

    Dolman, A.J.; Nonhebel, S.


    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

  16. Warming drives a front of white spruce establishment near western treeline, Alaska. (United States)

    Miller, Amy E; Wilson, Tammy L; Sherriff, Rosemary L; Walton, James


    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

  17. Spruce colonization at treeline: where do those seeds come from? (United States)

    Piotti, A; Leonardi, S; Piovani, P; Scalfi, M; Menozzi, P


    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.

  18. Developmental Trends of Black Spruce Fibre Attributes in Maturing Plantations

    Directory of Open Access Journals (Sweden)

    Peter F. Newton


    Full Text Available This study assessed the temporal developmental patterns of commercially relevant fibre attributes (tracheid length and diameters, wall thickness, specific surface area, wood density, microfibril angle, fibre coarseness, and modulus of elasticity and their interrelationships within maturing black spruce (Picea mariana (Mill. B.S.P. plantations. A size-based stratified random sample procedure within 5 semimature plantations located in the Canadian Boreal Forest Region was used to select 50 trees from which radial cross-sectional xylem sequences at breast-height (1.3 m were cut and analyzed. Statistically, the graphical and linear correlation analyses indicated that the attributes exhibited significant (p≤0.05 relationships among themselves and with morphological tree characteristics. Relative variation of each annually measured attribute declined with increasing size class (basal area quintile. The transitional shifts in temporal correlation patterns occurring at the time of approximate crown closure where suggestive of intrinsic differences in juvenile and mature wood formation processes. The temporal cumulative development patterns of all 8 of the annually measured attributes varied systematically with tree size and exhibited the most rapid rates of change before the trees reached a cambial age of 20 years. At approximately 50 years after establishment, plantation mean attribute values were not dissimilar from those reported for more mature natural-origin stands.

  19. Remote sensing of spruce budworm defoliation using EO-1 Hyperion hyperspectral data: an example in Quebec, Canada (United States)

    Huang, Z.; Zhang, Y.


    Each year, the spruce budworm (SBW) causes severe, widespread damage to spruces and fir in east coast Canada. Early estimation of the defoliation can provide crucial support to mitigate the socio-economic impact on vulnerable forests. Remote sensing techniques are suitable to investigate the affected regions that usually consist of large and inaccessible forestry areas. Using satellite images, surface reflectance values at two or more wavelengths are combined to generate vegetation indices (VIs), revealing a relative abundance of features of interest. Forest health analysis based on VIs is considered as one of the primary information sources for monitoring vegetation conditions. Especially the spectral resolution of Hyperion hyperspectral satellite imagery used in this study allows for a detailed examination of the red to near-infrared portion of the spectrum to identify areas of stressed vegetation. Several narrow-band vegetation indices are used to indicate the overall amount and quality of photosynthetic material and moisture content in vegetation. By integrating the information from VIs that focus on different aspects of overall health and vigour in forested areas, the study aims at detecting defoliated condition in a forested region in the Province of Quebec, Canada. In June and August of 2014 two Hyperion images were acquired by NASA's EO-1 satellite for this study. Changes in vegetation health and vigour are observed and quantitatively compared using the multi-temporal remote sensing images. The experimental results suggest that the VI- based forest health analysis is effective in estimating SBW defoliation in the study area.

  20. Shifts in soil testate amoeba communities associated with forest diversification. (United States)

    Bobrov, Anatoly A; Zaitsev, Andrei S; Wolters, Volkmar


    We studied changes of testate amoeba communities associated with the conversion of spruce monocultures into mixed beech-fir-spruce forests in the Southern Black Forest Mountains (Germany). In this region, forest conversion is characterized by a gradual development of beech undergrowth within thinned spruce tree stands leading to multiple age continuous cover forests with a diversified litter layer. Strong shifts in the abundance of testate amoeba observed in intermediate stages levelled off to monoculture conditions again after the final stage of the conversion process had been reached. The average number of species per conversion stage (i.e., local richness) did not respond strongly to forest conversion, but the total number of species (i.e., regional richness) was considerably higher in the initial stage than in the mixed forests, due to the large number of hygrophilous species inhabiting spruce monocultures. Functional diversity of the testate amoeba community, however, significantly increased during the conversion process. This shift was closely associated with improved C and N availability as well as higher niche diversity in the continuous cover stands. Lower soil acidity in these forests coincided with a higher relative abundance of eurytopic species. Our results suggest that testate amoeba communities are much more affected by physicochemical properties of the soil than directly by litter diversity.

  1. Putting community data to work: some understory plants indicate red spruce regeneration habitat (United States)

    Alison C. Dibble; John C. Brissette; Malcolm L. Hunter


    When harvested, red spruce (Picea rubens) at low elevations is vulnerable to temporary displacement by balsam fir (Abies balsamea) and hardwoods. If indicator plants can be found by which to assess spruce regeneration habitat, then biota dependent on red spruce dominance could benefit. Associations between spruce seedlings (0.1-0.5...

  2. Development of White and Norway Spruce Trees from Several Seed Sources 29 Years After Planting (United States)

    James P. King; Paul O. Rudolf


    A 29-year-old test of trees grown from seven white spruce and six Norway spruce seed sources and planted in Wisconsin and Minnesota demonstrates the importance of seed-source selection and indicates that trees from some Norway spruce sources equal or surpass the native white spruce.

  3. Preliminary Effects of Fertilization on Ecochemical Soil Condition in Mature Spruce Stands Experiencing Dieback in the Beskid Śląski and Żywiecki Mountains, Poland. (United States)

    Małek, Stanisław; Januszek, Kazimierz; Keeton, William S; Barszcz, Józef; Kroczek, Marek; Błońska, Ewa; Wanic, Tomasz


    In recent years, there has been the phenomena of spruce dieback in Europe. Significant areas of spruce low mortality now cover both sides of the Polish southern border. We evaluated ecochemical parameters influencing the heavy dieback occurring in mature spruce stands in the Polish Carpathian Mountains. Dolomite, magnesite and serpentinite fertilizers were applied to experimental plots located in 100-year-old stands in the autumn of 2008. The experimental plots were located in the mid-elevational forest zone (900-950 m) on two nappes of the flysch Carpathians: Magura (Ujsoły Forest District) and Silesian (Wisła Forest District). The saturation of the studied soils demonstrates moderate resilience of soils in Wisła Forest District in relation to acid load and high flexibility of the Ujsoły soils. After application of the fertilizers, an increase of Mg, Ca and Mb was noted in the soil solution, determined in the overlaying highly acidic organic horizons through the ion-exchange buffering mechanism of highly protonated functional groups with high buffering capacity. Magnesium concentration increased following fertilization, presenting a potential improvement of forest growth capacity without the hazard of adverse side effects of liming. Aluminium stress in old spruce is unlikely, while trees in the control plots in Wisła Forest District may already be sensitive to aluminium stress. Serpentinite fertilization improved the supply of soils in magnesium without causing significant changes in the pH of the soil. Such changes in the pH were found in dolomite and magnesite fertilizer.

  4. Application of GIS to Empirical Windthrow Risk Model in Mountain Forested Landscapes

    Directory of Open Access Journals (Sweden)

    Lukas Krejci


    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.

  5. 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


    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

  6. Limited evidence of declining growth among moisture-limited black and white spruce in interior Alaska. (United States)

    Sullivan, Patrick F; Pattison, Robert R; Brownlee, Annalis H; Cahoon, Sean M P; Hollingsworth, Teresa N


    Boreal forests play critical roles in global carbon, water and energy cycles. Recent studies suggest drought is causing a decline in boreal spruce growth, leading to predictions of widespread mortality and a shift in dominant vegetation type in interior Alaska. We took advantage of a large set of tree cores collected from random locations across a vast area of interior Alaska to examine long-term trends in carbon isotope discrimination and growth of black and white spruce. Our results confirm that growth of both species is sensitive to moisture availability, yet show limited evidence of declining growth in recent decades. These findings contrast with many earlier tree-ring studies, but agree with dynamic global vegetation model projections. We hypothesize that rising atmospheric [CO2] and/or changes in biomass allocation may have compensated for increasing evaporative demand, leaving recent radial growth near the long-term mean. Our results highlight the need for more detailed studies of tree physiological and growth responses to changing climate and atmospheric [CO2] in the boreal forest.

  7. Distinct genecological patterns in seedlings of Norway spruce and silver fir from a mountainous landscape. (United States)

    Frank, Aline; Sperisen, Christoph; Howe, Glenn Thomas; Brang, Peter; Walthert, Lorenz; St Clair, John Bradley; Heiri, Caroline


    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

  8. Short-term understory plant community responses to salvage logging in beetle-affected lodgepole pine forests (United States)

    Paula J. Fornwalt; Charles C. Rhoades; Robert M. Hubbard; Rebecca L. Harris; Akasha M. Faist; William D. Bowman


    Recent bark beetle outbreaks in western North American subalpine forests have prompted managers to salvage log some beetle-affected stands. We examined the short-term (i.e., two to three years post-treatment) consequences of such salvage logging on vascular understory plant (i.e., graminoid, forb, and shrub) communities. At 24 lodgepole pine (Pinus contorta) sites in...

  9. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato


    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  10. Allelopathic effect of phenolic acids from humic solutions on two spruce mycorrhizal fungi:Cenococcum graniforme andLaccaria laccata. (United States)

    Pellissier, F


    The aim of this investigation was to determine the impact ofp-hydroxyacetophenone,p-hydroxybenzoic acid, catechol, and protocatechuic acid on respiration of two spruce mycorrhizal fungi:Laccaria laccata andCenococcum graniforme. These phenols are produced byVaccinium myrtillus,Athyrium filixfemina, andPicea abies, predominant species of spruce forests in the Alps, and they are also present in humic solutions at 10(-10) M or 10(-5) M. Respiration of the two fungi was inhibited by the four phenolic acids, even at concentrations ranging from 10(-5) M to 10(-7) M. These data show phenolic acids from humic solutions have biological activity at extremely low concentrations, suggesting a contribution ofV. myrtillus, A. filixfemina, andP. abies to allelopathic inhibition of mycorrhizal fungi.

  11. Size-dependence of tree growth response to drought for Norway spruce and European beech individuals in monospecific and mixed-species stands. (United States)

    Ding, H; Pretzsch, H; Schütze, G; Rötzer, T


    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.

  12. The impact of small terrestrial mammals on beech (Fagus sylvatica plantations in spruce monoculture

    Directory of Open Access Journals (Sweden)

    Luboš Purchart


    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.

  13. Thermokarst Rates Intensify Due to Climate Change and Forest Fragmentation in an Alaskan Boreal Forest Lowland (United States)

    Lara, M. J.; Genet, H.; McGuire, A. D.; Euskirchen, E. S.; Zhang, Y.; Brown, D. N.; Jorgenson, T.; Romanovsky, V. E.; Breen, A. L.; Bolton, W. R.


    Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse scar-bogs, low shrub/scrub, and forests growing on elevated ice rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5o C of thawing. Increases in the collapse of lowland boreal forests in response to warming may have consequences for the climate system. This study evaluates the trajectories and potential drivers of 60 years of forest change in a landscape subjected to permafrost thaw in unburned dominant forest types (paper birch and black spruce) associated with location on elevated permafrost plateau and across multiple time periods (1949, 1978, 1986, 1998 and 2009) using historical and contemporary aerial and satellite images for change detection. We developed (i) a deterministic statistical model to evaluate the potential climatic controls on forest change using gradient boosting and regression tree analysis, and (ii) a 30x30 m land cover map of the Tanana Flats to estimate the potential landscape-level losses of forest area due to thermokarst from 1949 to 2009. Over the 60-year period, we observed a nonlinear loss of birch forests and a relatively continuous gain of spruce forest associated with thermokarst and forest succession, respectively. Gradient boosting and regression tree models identify precipitation and forest fragmentation as the primary factors controlling birch and spruce forest change, respectively. Between 1950-2009 landscape-level analysis estimates a transition of ~15 km² of birch forest area to wetlands on the Tanana Flats, where the greatest change followed warm periods. This work highlights the vulnerability of lowland

  14. Survival and growth patterns of white spruce (Picea glauca [Moench] Voss) rangewide provenances and their implications for climate change adaptation. (United States)

    Lu, Pengxin; Parker, William H; Cherry, Marilyn; Colombo, Steve; Parker, William C; Man, Rongzhou; Roubal, Ngaire


    Intraspecific assisted migration (ISAM) through seed transfer during artificial forest regeneration has been suggested as an adaptation strategy to enhance forest resilience and productivity under future climate. In this study, we assessed the risks and benefits of ISAM in white spruce based on long-term and multilocation, rangewide provenance test data. Our results indicate that the adaptive capacity and growth potential of white spruce varied considerably among 245 range-wide provenances sampled across North America; however, the results revealed that local populations could be outperformed by nonlocal ones. Provenances originating from south-central Ontario and southwestern Québec, Canada, close to the southern edge of the species' natural distribution, demonstrated superior growth in more northerly environments compared with local populations and performed much better than populations from western Canada and Alaska, United States. During the 19-28 years between planting and measurement, the southern provenances have not been more susceptible to freezing damage compared with local populations, indicating they have the potential to be used now for the reforestation of more northerly planting sites; based on changing temperature, these seed sources potentially could maintain or increase white spruce productivity at or above historical levels at northern sites. A universal response function (URF), which uses climatic variables to predict provenance performance across field trials, indicated a relatively weak relationship between provenance performance and the climate at provenance origin. Consequently, the URF from this study did not provide information useful to ISAM. The ecological and economic importance of conserving white spruce genetic resources in south-central Ontario and southwestern Québec for use in ISAM is discussed.

  15. Variation in winter snowpack depth and duration influences summer soil respiration in a subalpine meadow (United States)

    Arnold, C. L.; Ghezzehei, T. A.; Berhe, A. A.


    Subalpine meadows in the Sierra Nevada rely on the depth and duration of the winter snowpack to supply ample water to restore the water table in the meadow during the spring snowmelt. This study examines the role that interannual variability in the winter snowpack plays in the overall rate of summer soil respiration along a hydrologic gradient in a subalpine meadow. Carbon dioxide efflux from the meadow was measured from June through September in 2011 and 2012 using soil collars and a LICOR 8100A infrared gas analyzer. Preliminary results show that soil respiration rates are influenced by the hydrologic gradient across the meadow, with drier regions peaking earlier in the summer as compared to wetter regions. We also show that high snowpack years can suppress soil respiration in the meadow until late in the summer season as compared to low snowpack years, where soil respiration peaks early in the summer.

  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 (United States)

    John E. Major; Kurt H. Johnsen


    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. Norway spruce and spruce shoot aphid as indicators of traffic pollution

    Energy Technology Data Exchange (ETDEWEB)

    Viskari, E-L.; Koessi, S. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Holopainen, J.K. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Agricultural Research Centre, Plant Production Research, Jokioinen (Finland)


    Two-year-old Norway spruce (Picea abies (L.) Karst) seedlings were exposed to traffic emissions along roadsides with three different traffic densities and speed limits; highway, street and a quiet local road. The responses of the exposed seedlings as a host plant and those of spruce shoot aphid (Cinara pilicornis Hartig) were studied. The concentrations of soluble N and free amino acids, defence chemicals (total phenolics, monoterpenes) were analysed, and aphid growth and reproduction were studied. Along the highway, street and at the local road control site, the atmospheric concentrations of black carbon (BC) and oxides of N (NO{sub x}) were measured for 1 week during the experiment. The BC data indicate deposition of organic particulate compounds along the highway and street. The NO{sub x} concentrations along the highway and street showed great diurnal variation, but the average NO{sub x} concentrations were relatively low. Thus, no changes in N metabolism or growth of the exposed Norway spruce seedlings were found. Along the street, the concentrations of many individual free amino acids, such as proline, as well as total amino acid concentrations, were lower than at the associated control site. Correspondingly, there was also no increase in spruce shoot aphid mean relative growth rate. The aphid reproduction, however, increased along the highway and is suggested to be due to more conducive microclimatic conditions at the exposure site or lack of natural enemies. No changes in defence chemicals (total phenolics, monoterpenes) in relation to the traffic exposure were found. Instead, the microclimatic conditions (temperature, solar irradiation) seemed to affect the concentration of total phenolics. (Author)

  18. Factors influencing the spatial and temporal dynamics of engelmann spruce mortality during a spruce beetle outbreak on the Markagunt Plateau, Utah (United States)

    R. Justin DeRose; James N. Long


    Host conditions are known to influence spruce beetle population levels, but whether they influence the spatial and temporal patterns of beetle-caused mortality during an outbreak is unknown. Using dendrochronological techniques, we quantified the spatiotemporal dynamics of a modern (late 1980s through the early 2000s) spruce beetle outbreak in Engelmann spruce on the...

  19. Braking effect of climate and topography on global change-induced upslope forest expansion. (United States)

    Alatalo, Juha M; Ferrarini, Alessandro


    Forests are expected to expand into alpine areas due to global climate change. It has recently been shown that temperature alone cannot realistically explain this process and that upslope tree advance in a warmer scenario may depend on the availability of sites with adequate geomorphic/topographic characteristics. Here, we show that, besides topography (slope and aspect), climate itself can produce a braking effect on the upslope advance of subalpine forests and that tree limit is influenced by non-linear and non-monotonic contributions of the climate variables which act upon treeline upslope advance with varying relative strengths. Our results suggest that global climate change impact on the upslope advance of subalpine forests should be interpreted in a more complex way where climate can both speed up and slow down the process depending on complex patterns of contribution from each climate and non-climate variable.

  20. 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)


    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.)

  1. Yellowheaded spruce sawfly--its ecology and management. (United States)

    Steven A. Katovich; Deborah G. McCullough; Robert A. Haack


    Presents the biology and ecology of the yellowheaded spruce sawfly, and provides survey techniques and management strategies. In addition, it provides information on identification, classification, host range, and the historical records of outbreaks in the Lake States.

  2. Formation of ectomycorrhizae following inoculation of containerized Sitka spruce seedlings. (United States)

    C.G. Shaw; R. Molina


    Containerized Sitka spruce, [Picea sitchensis (Bong.) Carr.] were inoculated at sowing with pure cultures of either Pisolithus tinctorius (Pers.) Coker & Couch, Laccaria laccata (Scop. ex Fr.) Berk. & Br., Astraeus pteridis (Shear) Feller, Amanita pantherina...

  3. Adaptive Evolution and Demographic History of Norway Spruce (Picea Abies)


    Källman, Thomas


    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...

  4. Soil fauna and plant litter decomposition in tropical and subalpine forests (United States)

    G. Gonzalez; T.R. Seastedt


    The decomposition of plant residues is influenced by their chemical composition, the physical-chemical environment, and the decomposer organisms. Most studies interested in latitudinal gradients of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil organisms involved in the process....

  5. Modeling species’ realized climatic niche space and predicting their response to global warming for several western forest species with small geographic distributions (United States)

    Marcus V. Warwell; Gerald E. Rehfeldt; Nicholas L. Crookston


    The Random Forests multiple regression tree was used to develop an empirically based bioclimatic model of the presence-absence of species occupying small geographic distributions in western North America. The species assessed were subalpine larch (Larix lyallii), smooth Arizona cypress (Cupressus arizonica ssp. glabra...

  6. Bioecological principles of maintaining stability in mountain forest ecosystems of the Ukrainian Carpathians




    The forest cover of the Carpathians has been deeply transformed by productive activities over the past centuries. The forest cover, age and species structure of its ecosystems have been changed. Beech and fir forests were replaced by spruce monocultures. Consequently, nitrogen and mineral elements cycles changed, the genetic and population structures altered and the eco-stabilizing function of forests decreased. These negative trends make it desirable to process the bioecological principles o...

  7. Changes in soil nitrogen cycling under Norway spruce logging residues on a clear-cut (United States)

    Smolander, Aino; Lindroos, Antti-Jussi; Kitunen, Veikko


    In Europe, forest biomass is increasingly being used as a source of energy to replace fossil fuels. In practice, this means that logging residues, consisting of green branches and stem tops, are more commonly harvested. In 2012 logging residues were harvested from about one third of clear-cuts in Finland. Our aim was to study how logging residues affect soil organic matter quality, in particular soil N cycling processes and composition of certain groups of plant secondary compounds, tannins and terpenes. Compounds in these groups were of interest because they are abundant in logging residues, and they have been shown to control soil N cycling. In connection with clear-cutting a Norway spruce stand in southern Finland, we established a controlled field experiment by building logging residue piles (40 kg/m2) on study plots. The piles consisted of fresh spruce branches and tops with green foliage. Control plots with no residues were included (0 kg/m2). Changes in soil organic matter properties have now been monitored for three growing seasons. Logging residues affected organic layer properties strongly. For example, they increased net nitrification and nitrate concentrations. There were also increases in the concentrations of certain terpenes and condensed tannins due to the residues. The significance of logging residues on soil processes and properties will be shown.

  8. Varying selection differential throughout the climatic range of Norway spruce in Central Europe. (United States)

    Kapeller, Stefan; Dieckmann, Ulf; Schueler, Silvio


    Predicting species distribution changes in global warming requires an understanding of how climatic constraints shape the genetic variation of adaptive traits and force local adaptations. To understand the genetic capacity of Norway spruce populations in Central Europe, we analyzed the variation in tree heights at the juvenile stage in common garden experiments established from the species' warm-dry to cold-moist distribution limits. We report the following findings: First, 47% of the total tree height variation at trial sites is attributable to the tree populations irrespective of site climate. Second, tree height variation within populations is higher at cold-moist trial sites than at warm-dry sites and higher within populations originating from cold-moist habitats than from warm-dry habitats. Third, for tree ages of 7-15 years, the variation within populations increases at cold-moist trial sites, whereas it remains constant at warm-dry sites. Fourth, tree height distributions are right-skewed at cold-moist trial sites, whereas they are nonskewed, but platykurtic at warm-dry sites. Our results suggest that in cold environments, climatic conditions impose stronger selection and probably restrict the distribution of spruce, whereas at the warm distribution limit, the species' realized niche might rather be controlled by external drivers, for example, forest insects.

  9. 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.

  10. Availability of ectomycorrhizal fungi to black spruce above the present treeline in Eastern Labrador. (United States)

    Reithmeier, Laura; Kernaghan, Gavin


    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.

  11. 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.


    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).

  12. Planting stress in newly planted jack pine and white spruce. 1. Factors influencing water uptake. (United States)

    Grossnickle, S C


    Bareroot jack pine (Pinus banksiana Lamb.) seedlings (2 + 0) and bareroot white spruce (Picea glauca (Moench) Voss) transplants (1 1/2 + 1 1/2) were taken from cold storage and planted on a clearcut forest site in northeastern Ontario on several dates between May 6 and June 5 during which period soil temperature at 15 cm depth increased from 0 to 18 degrees C. Additional cold-stored trees were transferred to a greenhouse where they were grown in pots for 0, 7 or 28 days and then placed with their roots in aerated water maintained at one of a range of constant temperatures between 0 and 22 degrees C. In both species, daytime xylem pressure potentials (Psi(x)) and needle conductances (g(wv)) decreased with decreasing soil or water temperature. At all root temperatures, g(wv) was lower, and Psi(x) higher, in jack pine than in white spruce. After 28 days in the greenhouse, g(wv) of jack pine seedlings, and Psi(x) of white spruce, was higher than in plants just removed from cold storage. In both species, water-flow resistance through the soil-plant-atmosphere continuum (RSPAC) increased as root temperature decreased. At all root temperatures, RSPAC was higher in plants just removed from cold storage than in plants grown in the greenhouse for 28 days, during which time many new unsuberized roots were formed. At root temperatures above 10 degrees C, RSPAC of both species was higher in trees newly planted in mineral soil than in trees with roots in aerated water; presumably because the roots of planted trees had limited hydraulic contact with the soil. On the day following removal from cold storage, relative plant water flow resistance increased, in both species, more rapidly with declining root temperature than could be accounted for by the change with temperature in the viscosity of water, thus indicating an effect of temperature on root permeability. The same effect was evident in jack pine seedlings, but not white spruce transplants, that had been grown for 28 days in

  13. Severely insect-damaged forest: A temporary trap for red squirrels? (United States)

    Claire A. Zugmeyer; John L. Koprowski


    Recent insect infestations in the spruce-fir forest in the Pinalenno Mountains of southeastern Arizona provided an opportunity to document response to severe forest disturbance and existence of an ecological trap for an endemic montane isolate, the endangered Mt. Graham red squirrel (Tamiasciurus hudsonicus grahamensis). From September 2003 to...

  14. Modelling and economic evaluation of forest biome shifts under climate change in Southwest Germany (United States)

    Marc Hanewinkel; Susan Hummel; Dominik. Cullmann


    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...

  15. 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.


    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

  16. Pennsylvania boreal conifer forests and their bird communities: past, present, and potential (United States)

    Douglas A. Gross


    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...

  17. Managing forest disturbances and community responses: lessons from the Kenai Peninsula, Alaska. (United States)

    Courtney G. Flint; Richard. Haynes


    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...

  18. Estimation of forest structural parameters using 5 and 10 meter SPOT-5 satellite data (United States)

    Peter T. Wolter; Phillip A. Townsend; Brian R. Sturtevant


    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...

  19. Effects of permafrost melting on CO2 and CH4 exchange of a poorly drained black spruce lowland


    Wickland, Kimberly P.; Striegl, Robert G.; Neff, Jason C.; Sachs, Torsten


    Permafrost melting is occurring in areas of the boreal forest region where large amounts of carbon (C) are stored in organic soils. We measured soil respiration, net CO2 flux, and net CH4 flux during MaySeptember 2003 and March 2004 in a black spruce lowland in interior Alaska to better understand how permafrost thaw in poorly drained landscapes affects land-atmosphere CO2 and CH4 exchange. Sites included peat soils underlain by permafrost at ∼0.4 m depth (permafrost plateau, PP), four ...

  20. Forest biomass carbon stocks and variation in Tibet’s carbon-dense forests from 2001 to 2050 (United States)

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


    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

  1. Spruce budworm weight and fecundity: means, frequency distributions, and correlations for two populations (Lepidoptera: tortricidae) (United States)

    Nancy Lorimer; Leah S. Bauer


    Pupal weights and fecundities of spruce budworm from Minnesota had different means, coefficients of variation, and frequency distributions than spruce budworm from New Hampshire. The two variables were correlated in one of the populations but not the other.

  2. Xylem sap flow of Norway spruce after inoculation with the blue‐stain fungus Ceratocystis polonica

    National Research Council Canada - National Science Library

    Kirisits, T; Offenthaler, I


    In a field experiment, the sap flow of Norway spruce ( Picea abies ) was measured in response to inoculation with Ceratocystis polonica , a virulent fungal associate of the spruce bark beetle Ips typographus...

  3. Computational snow avalanche simulation in forested terrain (United States)

    Teich, M.; Fischer, J.-T.; Feistl, T.; Bebi, P.; Christen, M.; Grêt-Regamey, A.


    Two-dimensional avalanche simulation software operating in three-dimensional terrain is widely used for hazard zoning and engineering to predict runout distances and impact pressures of snow avalanche events. Mountain forests are an effective biological protection measure against avalanches; however, the protective capacity of forests to decelerate or even to stop avalanches that start within forested areas or directly above the treeline is seldom considered in this context. In particular, runout distances of small- to medium-scale avalanches are strongly influenced by the structural conditions of forests in the avalanche path. We present an evaluation and operationalization of a novel detrainment function implemented in the avalanche simulation software RAMMS for avalanche simulation in forested terrain. The new approach accounts for the effect of forests in the avalanche path by detraining mass, which leads to a deceleration and runout shortening of avalanches. The relationship is parameterized by the detrainment coefficient K [kg m-1 s-2] accounting for differing forest characteristics. We varied K when simulating 40 well-documented small- to medium-scale avalanches, which were released in and ran through forests of the Swiss Alps. Analyzing and comparing observed and simulated runout distances statistically revealed values for K suitable to simulate the combined influence of four forest characteristics on avalanche runout: forest type, crown closure, vertical structure and surface cover, for example, values for K were higher for dense spruce and mixed spruce-beech forests compared to open larch forests at the upper treeline. Considering forest structural conditions within avalanche simulations will improve current applications for avalanche simulation tools in mountain forest and natural hazard management.

  4. Hartig' net formation of Tricholoma vaccinum-spruce ectomycorrhiza in hydroponic cultures. (United States)

    Henke, Catarina; Jung, Elke-Martina; Kothe, Erika


    For re-forestation of metal-contaminated land, ectomycorrhizal trees may provide a solution. Hence, the study of the interaction is necessary to allow for comprehensive understanding of the mutually symbiotic features. On a structural level, hyphal mantle and the Hartig' net formed in the root apoplast are essential for plant protection and mycorrhizal functioning. As a model, we used the basidiomycete Tricholoma vaccinum and its host spruce (Picea abies). Using an optimized hydroponic cultivation system, both features could be visualized and lower stress response of the tree was obtained in non-challenged cultivation. Larger spaces in the apoplasts could be shown with high statistical significance. The easy accessibility will allow to address metal stress or molecular responses in both partners. Additionally, the proposed cultivation system will enable for other experimental applications like addressing flooding, biological interactions with helper bacteria, chemical signaling, or other biotic or abiotic challenges relevant in the natural habitat.

  5. Five-year measurements of ozone fluxes to a Danish Norway spruce canopy

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.; Hovmand, M.F.


    Ozone concentrations and fluxes have been measured continuously during 5 years (1996-2000) by the gradient method in a Norway spruce dominated forest stand in West Jutland, Denmark, planted in 1965. The method has been validated against other methodologies and a relatively good relationship...... resistance, r(c), are presented. The yearly ozone deposition is approximately 126 kg ha(-1). The canopy ozone uptake is highest during the day and during the summer. This is interpreted as increased stomatal uptake and physical and chemical reactions. The daily means of ozone concentration and fluxes...... averaged over 5 years correlate, but the correlation is primarily based on two different uncoupled processes outside and inside the stomates: (1) The ozone destruction in the canopy occurring outside the stomates is much influenced by temperature, light and humidity, e.g. surface reactions, NO- and VOC...

  6. Feedbacks of windthrow for Norway spruce and Scots pine stands under changing climate

    DEFF Research Database (Denmark)

    Panferov, O.; Döring, C.; Rauch, E.


    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...... 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  8. High-Throughput Sequencing Reveals Drastic Changes in Fungal Communities in the Phyllosphere of Norway Spruce (Picea abies) Following Invasion of the Spruce Bud Scale (Physokermes piceae). (United States)

    Menkis, Audrius; Marčiulynas, Adas; Gedminas, Artūras; Lynikienė, Jūratė; Povilaitienė, Aistė


    The aim of this study was to assess the diversity and composition of fungal communities in damaged and undamaged shoots of Norway spruce (Picea abies) following recent invasion of the spruce bud scale (Physokermes piceae) in Lithuania. Sampling was done in July 2013 and included 50 random lateral shoots from ten random trees in each of five visually undamaged and five damaged 40-50-year-old pure stands of P. abies. DNA was isolated from 500 individual shoots, subjected to amplification of the internal transcribed spacer of fungal ribosomal DNA (ITS rDNA), barcoded and sequenced. Clustering of 149,426 high-quality sequences resulted in 1193 non-singleton contigs of which 1039 (87.1 %) were fungal. In total, there were 893 fungal taxa in damaged shoots and 608 taxa in undamaged shoots (p < 0.0001). Furthermore, 431 (41.5 %) fungal taxa were exclusively in damaged shoots, 146 (14.0 %) were exclusively in undamaged shoots, and 462 (44.5 %) were common to both types of samples. Correspondence analysis showed that study sites representing damaged and undamaged shoots were separated from each other, indicating that in these fungal communities, these were largely different and, therefore, heavily affected by P. piceae. In conclusion, the results demonstrated that invasive alien tree pests may have a profound effect on fungal mycobiota associated with the phyllosphere of P. abies, and therefore, in addition to their direct negative effect owing physical damage of the tissue, they may also indirectly determine health, sustainability and, ultimately, distribution of the forest tree species.

  9. Photosynthesis in black and red spruce and their hybrid derivatives: ecological isolation and hybrid adaptive inferiority (United States)

    S.A.M Manley; F. Thomas Ledig


    Photosynthetic response5 of black and red spruce were used to define parameters of their fundamental niches. Grown at warm temperature, black spruce had highest rates of CO2 uptake at high light intensities, fitting it for a pioneering role, while red spruce had the lowest light compensation point, fitting it for a late successional role. Black...

  10. The current distribution, predictive modeling, and restoration potential of red spruce in West Virginia (United States)

    Gregory Nowacki; Dan. Wendt


    The environmental relationships of red spruce (Picea rubens Sarg.) were assessed in east-central West Virginia. Although many significant relationships existed, red spruce was most strongly associated with elevation, climate, and soil moisture factors. Specifically, red spruce was positively associated with elevation, number of frost days, mean...


    Directory of Open Access Journals (Sweden)

    O. I. Evstigneev


    Full Text Available Successional changes of pine forests were studied in outwash areas characterised by topography with ridges and depressions. The spatial series of pine forests of different stand ages and those that have not experienced the impact of human activities were analyzed. Pine forests in outwash areas form two successional series depending on the different ecotopes. The following successional series occurs at the tops of ridges: boreal green moss pine forest à boreal green moss – dwarf shrub forests à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. Another successional series is formed on gentle ridge slopes: boreal polytric pine forest à boreal bilberry-polytric pine forest à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. We show that ecotope has the leading role in the organisation of cenoses at the early stages of succession: green moss pine forests are formed at high and relatively dry relief sites (ridges and polytric pine forests are formed on relatively wet ridge slopes. The ecotopic mosaic is complicated by the vegetation pattern created by animals (e.g., seed hawkers at the intermediate stages of succession. Zoochoric species appear in the community: Vaccinium vitis-idaea, Convallaria majalis, Sorbus aucuparia and Quercus robur more often take root at the top of ridges; Vaccinium myrtillus, Frangula alnus and Picea abies grow on the slopes. The mosaic created by trees is imposed on a mosaic caused by ecotopes and animals at the final stages of succession: tree-fall gaps appear in the place of old dead trees with tree undergrowth. As a result, a heterogeneous community with a number of asynchronously developing gaps is formed in place of homogeneous pine forest

  12. European spruce bark beetle (Ips typographus, L.) green attack affects foliar reflectance and biochemical properties (United States)

    Abdullah, Haidi; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Groen, Thomas A.; Heurich, Marco


    The European spruce bark beetle Ips typographus, L. (hereafter bark beetle), causes major economic loss to the forest industry in Europe, especially in Norway Spruce (Picea abies). To minimise economic loss and preclude a mass outbreak, early detection of bark beetle infestation (so-called ;green attack; stage - a period at which trees are yet to show visual signs of infestation stress) is, therefore, a crucial step in the management of Norway spruce stands. It is expected that a bark beetle infestation at the green attack stage affects a tree's physiological and chemical status. However, the concurrent effect on key foliar biochemical such as foliar nitrogen and chlorophyll as well as spectral responses are not well documented in the literature. Therefore, in this study, the early detection of bark beetle green attacks is investigated by examining foliar biochemical and spectral properties (400-2000 nm). We also assessed whether bark beetle infestation affects the estimation accuracy of foliar biochemicals. An extensive field survey was conducted in the Bavarian Forest National Park (BFNP), Germany, in the early summer of 2015 to collect leaf samples from 120 healthy and green attacked trees. The spectra of the leaf samples were measured using an ASD FieldSpec3 equipped with an integrating sphere. Significant differences (p < 0.05) between healthy and infested needle samples were found in the mean reflectance spectra, with the most pronounced differences being observed in the NIR and SWIR regions between 730 and 1370 nm. Furthermore, significant differences (p < 0.05) were found in the biochemical compositions (chlorophyll and nitrogen concentration) of healthy versus green attacked samples. Our results further demonstrate that the estimation accuracy of foliar chlorophyll and nitrogen concentrations, utilising partial least square regression model, was lower for the infested compared to the healthy trees. We show that early stage of infestation reduces not only

  13. Resurgence of human bothriocephalosis (Diphyllobothrium latum in the subalpine lake region

    Directory of Open Access Journals (Sweden)



    Full Text Available Human bothriocephalosis is once again being found in various catchment basins in the subalpine region, including Lago Maggiore and Lac Léman, which however are not isolated cases. Domestic animals are thought to be responsible for the survival of the parasite during the period when no human cases were reported. The new phenomenon of eating raw or poorly cooked fish is responsible for the resurgence of human bothriocephalosis, which affects various lake districts in Europe. This habit of eating raw fish might lead to the resurgence of a much more dangerous human parasitosis, transmitted in a similar way: infestation by Anisakis.

  14. The joint influence of photoperiod and temperature during growth cessation and development of dormancy in white spruce (Picea glauca). (United States)

    Hamilton, Jill A; El Kayal, Walid; Hart, Ashley T; Runcie, Daniel E; Arango-Velez, Adriana; Cooke, Janice E K


    Timely responses to environmental cues enable the synchronization of phenological life-history transitions essential for the health and survival of north-temperate and boreal tree species. While photoperiodic cues will remain persistent under climate change, temperature cues may vary, contributing to possible asynchrony in signals influencing developmental and physiological transitions essential to forest health. Understanding the relative contribution of photoperiod and temperature as determinants of the transition from active growth to dormancy is important for informing adaptive forest management decisions that consider future climates. Using a combination of photoperiod (long = 20 h or short = 8 h day lengths) and temperature (warm = 22 °C/16 °C and cool = 8 °C/4 °C day/night, respectively) treatments, we used microscopy, physiology and modeling to comprehensively examine hallmark traits of the growth-dormancy transition-including bud formation, growth cessation, cold hardiness and gas exchange-within two provenances of white spruce [Picea glauca (Moench) Voss] spanning a broad latitude in Alberta, Canada. Following exposure to experimental treatments, seedlings were transferred to favorable conditions, and the depth of dormancy was assessed by determining the timing and ability of spruce seedlings to resume growth. Short photoperiods promoted bud development and growth cessation, whereas longer photoperiods extended the growing season through the induction of lammas growth. In contrast, cool temperatures under both photoperiodic conditions delayed bud development. Photoperiod strongly predicted the development of cold hardiness, whereas temperature predicted photosynthetic rates associated with active growth. White spruce was capable of attaining endodormancy, but its release was environmentally determined. Dormancy depth varied substantially across experimental treatments suggesting that environmental cues experienced within one season could affect growth

  15. Ash recycling to spruce and beech stands effects on nutrients, growth, nitrogen dynamics and carbon balance; Askaaterfoering till gran- och bokbestaand - effekter paa naering, tillvaext, kvaevedynamik och kolbalans

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar


    Ash recycling is an important part in a modern, sustainable forestry, especially in whole-tree harvest systems. Nutrients lost at harvest are returned to the forest with the wood-ash. In the project the effects of ash treatment on needle and leaf chemistry, tree growth, soil chemistry, soil water chemistry, and carbon and nitrogen dynamics were studied on 23 Norway spruce sites in south-western Sweden and in ten European beech sites in Scania, southern Sweden. On some of the sites there were previously established ash recycling experiments, but on a majority of the sites ash recycling was performed without experimental lay-out and ash and control plots were established afterwards. The most common dose was two tons of self hardened crushed wood-ash and two tons of Mg-lime. On average seven to eight years after ash recycling the results were 1. increased exchangeable stores of base cations in the soil in the beech and the spruce stands 2. increased base saturation in the beech and the spruce stands and increased BC/Al in the spruce stands 3. increased concentrations and ratios to N of P, Ca, Zn, and S in the needles, the increased P-values are especially important since P is close to or below deficiency levels in a majority of the spruce stands 4. decreased K-concentration in the beech leaves 5. increased tree growth with on average 14 % in the ash treated spruce stands compared to the control plots 6. increased carbon and nitrogen amounts in the biomass in the spruce stands 7. tendencies towards increased amounts of carbon and nitrogen in the soil in the beech stands and no effect in the soil in the spruce stands 8. increased concentrations of Ca, Mg, and SO{sub 4} and no effect on ANC in the soil water 9. no effect on potential net mineralization but increased potential nitrification rates 10. decreased concentration of nitrate in the soil water in the beech stands and no effect in the spruce stands 11. lower system N losses in the beech stands and possibly in the

  16. Experimental warming delays autumn senescence in a boreal spruce bog: Initial results from the SPRUCE experiment (United States)

    Richardson, Andrew; Furze, Morgan; Aubrecht, Donald; Milliman, Thomas; Nettles, Robert; Krassovski, Misha; Hanson, Paul


    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 ( 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

  17. Response of Lutz, Sitka, and white spruce to attack by Dendroctonus rufipennis (Coleoptera: Scolytidae) and blue stain fungi (United States)

    Richard A. Werner; Barbara L. Illman


    Mechanical wounding and wounding plus inoculation with a blue-stain fungus, Leptographium abietinum (Peck), associated with the spruce beetle, Dendroctonus rufipennis (Kirby), caused an induced reaction zone or lesion around the wound sites in Lutz spruce, Picea lutzii Little, Sitka spruce, P. sitchensis (Bong.) Carr., and white spruce, P. glauca (Moench) Voss, in...

  18. Soil attributes as viable agents in red spruce mortality along the southern Appalachian highlands with applications as field and laboratory exercises for community college science courses (United States)

    Ashbrook, Craig Monday

    The southern Appalachian highlands displaying peaks above 1500m frequently support a northern boreal forest. These highland forests sustain both red spruce and Fraser fir trees, which are typically aboriginal to the northeastern United States and southeastern Canada. Within the past century, these forests have declined at an unusual rate. Past studies have focused on the impacts of acid deposition and similar atmospheric pollutants. However, the scientific community found difficulty in establishing a cause-and-effect relationship between the decline and these atmospheric pollutants. This dissertation focuses on a heavily neglected and often overlooked factor, which creates restrictions in growth patterns and overall health of these boreal trees. That overlooked factor deals primarily with soil nutrients within a selected spruce-fir stand of the southern Appalachians. The research quantitatively analyzes soils for specific chemical and physical properties, with comparisons made to soils from the New England region where the spruces and firs grow indigenously. A fundamental part of understanding ecosystems is the environmental interrelationships within those ecosystems. This document organizes a series of laboratory exercises, which target community college science courses so student exploration of these interrelationships becomes an integral part of the laboratory procedures. By completing these various exercises, students become more aware of the connective character of nature as well as develop an appreciation of geography, the original environmental science. Although atmospheric pollutants should continue to be scrutinized, findings of this research document show that the natural characteristics of soils are clearly a limiting factor in the overall health and vitality of the southern boreal forests. Therefore, future research, regardless of the focus, should include soil characteristics as a viable factor in the health of these delicate forest-types.

  19. Long-term trends in radial growth of Siberian spruce and Scots pine in Komi Republic (northwestern Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Lopatin, E. (Univ. of Joensuu (Finland)); Kolstroem, T. (Russian Academy of Sciences, Syktyvkar (Russian Federation)); Spiecker, H. (Univ. of Freiburg (Germany))


    Komi is situated on the eastern boundary of the European part of Russia, in the boreal region where large areas of natural forest still exist. Using radial growth measurements it was possible to attain positive long-term trends of growth in Scots pine (Pinus sylvestris) and Siberian spruce (Picea obovata) in the Komi Republic. Increases in the radial growth of Siberian spruce in the forest-tundra were 134% and in the northern taiga zone 35% over successive 50-year periods from 1901 to 1950 and from 1951 to 2000. Respectively, in the middle taiga zone a 76% increase in radial growth was found (over 100 years), whilst in the southern taiga zone the changes were not statistically significant. The increase in radial growth of Scots pine in the northern taiga zone was 32%. In the middle taiga zone the radial growth increase in Scots pine was 55% and in the southern taiga zone the changes were not statistically significant. The long-term growth trends of Komi were compared with those in other parts of Europe. (orig.)

  20. Moisture content of Norway spruce (Picea Abies (L.) Karst.) stump wood at clear cutting areas and roadside storage sites

    Energy Technology Data Exchange (ETDEWEB)

    Laurila, J.; Lauhanen, R. (Seinaejoki Univ. of Applied Sciences, Aehtaeri (Finland), School of Agriculture and Forestry), e-mail:, e-mail:


    The use of Norway spruce (Picea abies (L.) Karst.) stump wood in heat energy production has recently increased in Finland. Cost effective stump wood procurement is a sum of many factors. In this study, the moisture content of Norway spruce stump wood at the clear cutting areas and forest roadside storage sites was examined. The moisture content of wood has a large effect on the transportation costs and heating value of wood. The average moisture content of stump wood was 53 % at the clear cutting areas immediately after harvesting. At the beginning the moisture content decreased fairly quickly being about 31 % one month after harvesting. If stumps dried well in the summer, water absorption was fairly slow in the autumn. Each spring and summer the moisture content was lower than during the previous year. On the whole, the stumps at the forest roadside storage sites were combustible at any point during the three year period except a one month drying period immediately after harvesting

  1. Changes in winter conditions impact forest management in north temperate forests. (United States)

    Rittenhouse, Chadwick D; Rissman, Adena R


    Climate change may impact forest management activities with important implications for forest ecosystems. However, most climate change research on forests has focused on climate-driven shifts in species ranges, forest carbon, and hydrology. To examine how climate change may alter timber harvesting and forest operations in north temperate forests, we asked: 1) How have winter conditions changed over the past 60 years? 2) Have changes in winter weather altered timber harvest patterns on public forestlands? 3) What are the implications of changes in winter weather conditions for timber harvest operations in the context of the economic, ecological, and social goals of forest management? Using meteorological information from Climate Data Online and Autoregressive Integrated Moving Average (ARIMA) models we document substantial changes in winter conditions in Wisconsin, including a two- to three-week shortening of frozen ground conditions from 1948 to 2012. Increases in minimum and mean soil temperatures were spatially heterogeneous. Analysis of timber harvest records identified a shift toward greater harvest of jack pine and red pine and less harvest of aspen, black spruce, hemlock, red maple, and white spruce in years with less frozen ground or snow duration. Interviews suggested that frozen ground is a mediating condition that enables low-impact timber harvesting. Climate change may alter frozen ground conditions with complex implications for forest management. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Subalpine Pyrenees received higher nitrogen deposition than predicted by EMEP and CHIMERE chemistry-transport models (United States)

    Boutin, Marion; Lamaze, Thierry; Couvidat, Florian; Pornon, André


    Deposition of reactive nitrogen (N) from the atmosphere is expected to be the third greatest driver of biodiversity loss by the year 2100. Chemistry-transport models are essential tools to estimate spatially explicit N deposition but the reliability of their predictions remained to be validated in mountains. We measured N deposition and air concentration over the subalpine Pyrenees. N deposition was found to range from 797 to 1,463 mg N m-2 year-1. These values were higher than expected from model predictions, especially for nitrate, which exceeded the estimations of EMEP by a factor of 2.6 and CHIMERE by 3.6. Our observations also displayed a reversed reduced-to-oxidized ratio in N deposition compared with model predictions. The results highlight that the subalpine Pyrenees are exposed to higher levels of N deposition than expected according to standard predictions and that these levels exceed currently recognized critical loads for most high-elevation habitats. Our study reveals a need to improve the evaluation of N deposition in mountains which are home to a substantial and original part of the world’s biodiversity.

  3. Population densities of northern Saw-whet Owls (Aegolius acadicus) in degraded boreal forests of the southern Appalachians (United States)

    Timothy C. Milling; Matthew P. Rowe; Bennie L. Cockerel; Timothy A. Dellinger; Johnny B. Gailes; Christopher E. Hill


    A disjunct population of the Northern Saw-whet Owl (Aegolius acadicus) breeds in the montane spruce-fir forests of the southern Appalachian Mountains. These forests are listed as the second most endangered ecosystem in the United States, having suffered from logging and massive fir die-off from the exotic balsam woolly adelgid. We used audio...

  4. Remote sensing of forest decline in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Ardoe, J.


    This thesis describes the localization and quantification of deforestation and forest damage in Norway spruce forests in northern Czech Republic using Landsat data. Severe defoliation increases the spectral reflectance in all wavelength bands, especially in the mid infrared region. These spectral differences allow the separation of three damage categories with an accuracy of 75% using TM data and regression based relationships. Estimating the same categories using an artificial neural network, multi temporal TM data and topographic data yields slightly higher accuracy (78%). The methods are comparable when using identical input data, but the neural network more efficiently manage large input data sets without pre.processing, The estimated coniferous deforestation in northern Bohemia from 1972 to 1989 reveals especially affected areas between 600 and 1000 m.a.s.l. and on slopes facing south and southeast. The sector downwind a large source of sulphur dioxide was strongly deforested. Comparing regional forest damage statistics to three methods estimating harmful effects of sulphur dioxide on Norway spruce yielded significant relationships versus level of forest damage and accumulated salvage felling. Quantifying the effect of data uncertainties permit mapping the probabilities of areas to be significantly over or below thresholds for harmful effects on spruce forests. Satellite based estimation of coniferous forest health is a good complement to field surveys and aerial photography 137 refs, 7 figs, 2 tabs

  5. Survival, frost susceptibility, growth, and disease resistance of corkbark and subalpine fir grown for landscape and Christmas trees (United States)

    Trees from six corkbark fir (Abies lasiocarpa var. arizonica) and 10 subalpine fir (A. lasiocarpa var. lasiocarpa) seed sources were grown at the University of Idaho Sandpoint Research and Extension Center (SREC) and two commercial nurseries in Idaho and Oregon. Post transplant mortality was highest...

  6. Mycorrhiza-plant colonization patterns on a subalpine glacier forefront as a model system of primary succession (United States)

    Efren Cazares; James M. Trappe; Ari Jumpponen


    Lyman glacier in the North Cascades Mountains of Washington has a subalpine forefront characterized by a well-developed terminal moraine, inconspicuous successional moraines, fluting, and outwash. These deposits were depleted of symbiotic fungi when first exposed but colonized by them over time after exposure. Four major groups of plant species in this system are (1)...

  7. Nonlinearities, scale-dependence, and individualism of boreal forest trees to climate forcing (United States)

    Wolken, J. M.; Mann, D. H.; Grant, T. A., III; Lloyd, A. H.; Hollingsworth, T. N.


    Our understanding of the climate-growth relationships of trees are complicated by the nonlinearity and variability of these responses through space and time. Furthermore, trees growing at the same site may exhibit opposing growth responses to climate, a phenomenon termed growth divergence. To date the majority of dendrochronological studies in Interior Alaska have involved white spruce growing at treeline, even though black spruce is the most abundant tree species. Although changing climate-growth relationships have been observed in black spruce, there is little known about the multivariate responses of individual trees to temperature and precipitation and whether or not black spruce exhibits growth divergences similar to those documented for white spruce. To evaluate the occurrence of growth divergences in black spruce, we collected cores from trees growing on a steep, north-facing toposequence having a gradient in environmental parameters. Our overall goal was to assess how the climate-growth relationships of black spruce change over space and time. Specifically, we evaluated how topography influences the climate-growth relationships of black spruce and if the growth responses to climate are homogeneous. At the site-level most trees responded negatively to temperature and positively to precipitation, while at the tree-level black spruce exhibited heterogenous growth responses to climate that varied in both space (i.e., between sites) and time (i.e., seasonally and annually). There was a dominant response-type at each site, but there was also considerable variability in the proportion of trees exhibiting each response-type combination. Even in a climatically extreme setting like Alaska's boreal forest, tree responses to climate variability are spatially and temporally complex, as well as highly nonlinear.

  8. Fire ecology and management of the major ecosystems of southern Utah (United States)

    Sharon M. Hood; Melanie Miller


    This document provides managers with a literature synthesis of the historical conditions, current conditions, fire regime condition classes (FRCC), and recommended treatments for the major ecosystems in southern Utah. Sections are by ecosystems and include: 1) coniferous forests (ponderosa pine, mixed conifer, and Engelmann spruce-subalpine fir), 2) aspen, 3) pinyon-...

  9. Les Gorges de Trévans dans le front subalpin – Un site exceptionnel des Alpes de Haute-Provence

    Directory of Open Access Journals (Sweden)

    Jean Nicod


    Full Text Available Les canyons de Trévans sont incisés dans des unités calcaires jurassiques, dans la zone frontale subalpine, proche du piémont de Valensole. Ces reliefs sont en rapport avec les phases néotectoniques. Ce secteur fait principalement partie de la forêt domaniale du Montdenier, avec des écosystèmes montagnards et supra-méditerranéens, bois de hêtres et de chênes pubescents, large extension des brousses et d'importants reboisements en pins noirs. Les hautes surfaces conservent des traces d'un ancien aplanissement et des sols résiduels paléokarstiques. Sur les pentes, sous des escarpements démembrés, les éboulis et convois de blocs témoignent des processus périglaciaires hérités et, localement, des évènements séismiques. De nombreux processus dynamiques s'observent dans les canyons : éboulements provenant des parois affectées des effets de détente, coups de gouge et marmites de géant dans leur fond excavé par les écoulements turbulents dans les cascades… et le Pont de Tuf.The canyon system of Trevans has cut the blocks of the jurassic limestones, in subalpine over thrust front, near the Valensole piedmont. These landforms are in relationship with the neotectonic movements. This area belongs to the State Forest of Montdenier, woodland of various mountain and supra-mediterranean ecosystems, with beeches and white oaks Quercus pubescens, large extent of bush and important reforestation in black pines (Pinus nigra. The high surfaces preserve some relics of the old planation and paleokarstic forms and residual soils. On the slopes, under the break-up escarpments, the screes and landslides give the part of the periglacial processes and, locally, of the seismic events. Numerous dynamic processes occur in the canyons: rock-slides, in relationship with open fractures, scallops and pot-holes in the bottom excavated by the turbulent flows in the waterfalls of the creeks and, only case, a travertine bridge.

  10. Patterns of cross-continental variation in tree seed mass in the Canadian Boreal Forest.

    Directory of Open Access Journals (Sweden)

    Jushan Liu

    Full Text Available Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill. B.S.P., white spruce (Picea glauca (Moench Voss and jack pine (Pinus banksiana Lamb across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively, indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they

  11. Indicators and associated decay of Engelmann spruce in Colorado (United States)

    Thomas E. Hinds; Frank G. Hawksworth


    Average cull deductions for 11 cull indicators were determined from over 2,000 abnormalities on 1,027 merchantable Engelmann spruce in 21 stands throughout Colorado. On a board-foot basis, Fomes pini punk knots or sporophores caused an 81 percent deduction. Deduction for broken tops or dead tops with adjacent dead rust brooms amounted to 24 percent....

  12. Reproductive compatibility within and among spruce budworm (Lepidoptera: tortricidae) populations (United States)

    Nancy Lorimer; Leah S. Bauer


    Spruce budworm moths collected as larvae from two species of host trees in four populations were mated in single pairs in two years. In 1980 but not 1981, more of the intra-population matings than the inter-population matings were fertile. Host tree origin was not a significant factor in the level of sterility.

  13. Carbon sources in vertical profile of Norway spruce stand

    Czech Academy of Sciences Publication Activity Database

    Pavelka, Marian; Janouš, Dalibor; Urban, Otmar; Acosta, Manuel; Pokorný, Radek; Havránková, Kateřina; Formanek, P.


    Roč. 2, č. 30 (2003), s. 199-206 ISSN 1336-5266 R&D Projects: GA MŠk(CZ) LN00A141; GA ČR(CZ) GA526/03/1021 Institutional research plan: CEZ:AV0Z6087904 Keywords : Carbon stock * respiration * Norway spruce Subject RIV: EH - Ecology, Behaviour

  14. Red spruce/hardwood ecotones in the central Appalachians (United States)

    Harold S. Adams; Steven L. Stephenson; David M. Lawrence; Mary Beth Adams; John D. Eisenback


    We are currently investigating patterns of species composition and distribution, ecologically important population processes, and microenvironmental gradients along ten permanent transects (each consisting of a series of. contiguous 10 x 10 m quadrats) established across the typically abrupt and narrow spruce/hardwood ecotone at seven localities in the mountains of...

  15. Leaf area dynamics of a boreal black spruce fire chronosequence. (United States)

    Bond-Lamberty, B; Wang, C; Gower, S T; Norman, J


    Specific leaf area (SLA) and leaf area index (LAI) were estimated using site-specific allometric equations for a boreal black spruce (Picea mariana (Mill.) BSP) fire chronosequence in northern Manitoba, Canada. Stands ranged from 3 to 131 years in age and had soils that were categorized as well or poorly drained. The goals of the study were to: (i) measure SLA for the dominant tree and understory species of boreal black spruce-dominated stands, and examine the effect of various biophysical conditions on SLA; and (ii) examine leaf area dynamics of both understory and overstory for well- and poorly drained stands in the chronosequence. Overall, average SLA values for black spruce (n = 215), jack pine (Pinus banksiana Lamb., n = 72) and trembling aspen (Populus tremuloides Michx., n = 27) were 5.82 +/- 1.91, 5.76 +/- 1.91 and 17.42 +/- 2.21 m2 x kg-1, respectively. Foliage age, stand age, vertical position in the canopy and soil drainage had significant effects on SLA. Black spruce dominated overstory LAI in the older stands. Well-drained stands had significantly higher overstory LAI (P 40%) of total leaf area in all stands except the oldest.

  16. Isolated ecosystems on supercooled scree slopes in subalpine environments - interaction between permafrost, soil and vegetation (United States)

    Schwindt, Daniel; Kozák, Johanna-Luise; Kohlpaintner, Michael


    forest growth. Ellenberg pointer values in central parts of the study sites showed a strong plant adaption to cold temperatures. However, plant sociological analysis did not indicate one clear azonal community, but two different permafrost-plant-communities, one adapted to acidic and the other to calcareous substrates. Dwarf grown trees (e.g. spruce, 63cm high, 122 years old) could be found in permafrost-affected areas of all study sites, while the same species developed normally in the surroundings. Main factor for the physiognomic adaptation seems to be the low temperature in the rooting zone and the correlated shorter vegetation period, as air temperatures and nutrient supplies between the permafrost affected area and its surroundings are comparable. Pronounced interdependencies between frozen ground distribution, vegetation cover and soil development could be verified for all sites. The supercooled subsurface causes reduced decomposition of organic material as well as dwarfing of trees. In return, Tangelhumus and dwarfed trees positively affect supercooling. Dry organic material thermally insulates the subsurface during summer and prevents/delays thawing, while the high thermal conductivity of the moist or frozen Tangelhumus enhances heat flow and supercooling in winter. In addition, dwarfed trees prevent the formation of a consistent insulating snow cover optimizing thermal fluxes between atmosphere and subsurface.

  17. Growth-melt asymmetry in ice crystals under the influence of spruce budworm antifreeze protein

    Energy Technology Data Exchange (ETDEWEB)

    Pertaya, Natalya [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Celik, Yeliz [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); DiPrinzio, Carlos L [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States); Wettlaufer, J S [Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109 (United States); Davies, Peter L [Department of Biochemistry, Queen' s University, Kingston, ON K7L 3N6 (Canada); Braslavsky, Ido [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States)


    Here we describe studies of the crystallization behavior of ice in an aqueous solution of spruce budworm antifreeze protein (sbwAFP) at atmospheric pressure. SbwAFP is an ice binding protein with high thermal hysteresis activity, which helps protect Choristoneura fumiferana (spruce budworm) larvae from freezing as they overwinter in the spruce and fir forests of the north eastern United States and Canada. Different types of ice binding proteins have been found in many other species. They have a wide range of applications in cryomedicine and cryopreservation, as well as the potential to protect plants and vegetables from frost damage through genetic engineering. However, there is much to learn regarding the mechanism of action of ice binding proteins. In our experiments, a solution containing sbwAFP was rapidly frozen and then melted back, thereby allowing us to produce small single crystals. These maintained their hexagonal shapes during cooling within the thermal hysteresis gap. Melt-growth-melt sequences in low concentrations of sbwAFP reveal the same shape transitions as are found in pure ice crystals at low temperature (-22 deg. C) and high pressure (2000 bar) (Cahoon et al 2006 Phys. Rev. Lett. 96 255502); while both growth and melt shapes display faceted hexagonal morphology, they are rotated 30 deg. relative to one another. Moreover, the initial melt shape and orientation is recovered in the sequence. To visualize the binding of sbwAFP to ice, we labeled the antifreeze protein with enhanced green fluorescent protein (eGFP) and observed the sbwAFP-GFP molecules directly on ice crystals using confocal microscopy. When cooling the ice crystals, facets form on the six primary prism planes (slowest growing planes) that are evenly decorated with sbwAFP-GFP. During melting, apparent facets form on secondary prism planes (fastest melting planes), leaving residual sbwAFP at the six corners of the hexagon. Thus, the same general growth-melt behavior of an apparently

  18. Effects of Boreal Well Site Reclamation Practices on Long-Term Planted Spruce and Deciduous Tree Regeneration

    Directory of Open Access Journals (Sweden)

    Laurie A. Frerichs


    Full Text Available Well site development associated with oil sands exploration is common in boreal mixedwood forests of northern Alberta, Canada, and necessitates reforestation to accommodate other land uses. Little is known about the impact of soil and debris handling strategies during well site construction on long-term forest regeneration. This study addresses the impact of soil disturbance intensity, debris treatment, soil storage, and planting on the reforestation of 33 well sites reclaimed prior to 2006. Data on the survival and growth of planted white spruce (Picea glauca (Moench Voss and the regeneration density of deciduous trees, including trembling aspen (Populus tremuloides Michx, are presented from 2014 to 2015. The survival of planted spruce increased from 81% to 88% at well sites with a high relative to low soil disturbance. The total tree densities were lower in most treatments (≤2.69 stems m−2 than those in clear cuts (5.17 stems m−2, with the exception of root salvage areas where clear cuts had greater balsam poplar (Populus balsamifera L. densities (2.05 stems m−2 vs. <0.71 stems m−2 on all other treatments. Aspen densities were up to five times greater at well sites with low disturbance when compared to those with high disturbance, and this was further aided by shallow mulch at low disturbance sites. Spruce growth did not respond to well site treatments. Aspen growth (diameter and height remained similar between well site disturbance regimes; aspen exposed to high disturbance underperformed relative to low disturbance well sites and clear cut controls. With high disturbance, progressive soil piling led to increases in the density of aspen and birch (Betula papyrifera Marshall. Few long-term changes in soil were found due to well site development, with a greater soil pH in high disturbance sites compared to low disturbance sites. Overall, these results indicate that the nature of well site construction, including the extent of soil

  19. Resistance and resilience of forest soils in the Limestone Alps (United States)

    Katzensteiner, K.; Darabant, A.; Gratzer, G.


    During the last decades a dramatic increase in frequency and extent of forest disturbances, in particular of bark beetle infestations after windthrows, can be observed in Austria. In protective forests of the montane and subalpine vegetation zone, forest recovery can take several decades - a period of altered micro-climatic conditions and nutrient cycles. Soils on calcareous bedrock are considered to be particularly vulnerable under these conditions. Erosion and disintegration of ecto-organic layers of folic Histosols (Tangel) and lithic and rendzic Leptosols will lead to a loss of soil functions. In a pilot study on resilience of protective forests, soil development along chronosequences of windthrows has been surveyed in three climatically different test regions. Multivariate statistics uncover the relation between micro-topography, time since disturbance, and vegetation status on the one hand and morphological characteristics, carbon and nitrogen stocks of soils on the other hand. Factors affecting resistance and resilience of soils on calcareous bedrock are discussed.

  20. Local adaptations and climate change: converging sensitivity of bud break in black spruce provenances (United States)

    Rossi, Sergio


    Species with transcontinental distribution or spread over wide geographical regions develop populations with growth traits genetically adapted to the local climate. The aim of this study was to investigate the ecotypic sensitivity of bud break, a strong adaptive trait, to a changing environment. Six phenological phases of bud break were monitored daily on black spruce [ Picea mariana (Mill.) BSP] seedlings submitted to different temperatures (12, 16 and 20 °C) and photoperiods (14, 18 and 22 h). Six provenances were tested in growth chambers, produced from seeds collected along the whole latitudinal range of the closed boreal forest in Quebec, Canada. Bud break lasted 13.3 days on average and occurred earlier in seedlings from colder sites. The annual temperature of the sites suitably tracked the clinal variation among ecotypes, providing a clear biological explanation for the environmental signal driving the adaptive divergence of populations to the local climate. Increasing temperature induced an earlier bud break according to a non-linear pattern with greater advancements observed between 12 and 16 °C. Photoperiod was significant, but sensitivity analysis indicated that its effect on bud break was marginal with respect to temperature. No interaction of provenance × treatment was observed, demonstrating an ecotypic convergence of the responses to both factors. Changes in the growing conditions could substantially modify the synchronization between bud phenology and climate, thus exposing the developing meristems of black spruce to frost damage. However, similar advancements of bud break could be expected in the different ecotypes subjected to warmer temperatures or longer day lengths.