WorldWideScience

Sample records for old-growth douglas-fir forest

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

    Science.gov (United States)

    B.B. Bingham; J.O. Sawyer

    1992-01-01

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

  2. The importance of amino sugar turnover to C and N cycling in organic horizons of old-growth Douglas-fir forest soils colonized by ectomycorrhizal mats

    Science.gov (United States)

    L. Zeglin; L.A. Kluber; D.D. Myrold

    2012-01-01

    Amino sugar dynamics represent an important but under-investigated component of the carbon (C) and nitrogen (N) cycles in old-growth Douglas-fir forest soils. Because fungal biomass is high in these soils, particularly in areas colonized by rhizomorphic ectomycorrhizal fungal mats, organic matter derived from chitinous cell wall material (or the monomeric building...

  3. Spatial and population characteristics of dwarf mistletoe infected trees in an old-growth Douglas-fir - western hemlock forest.

    Science.gov (United States)

    David C. Shaw; Jiquan Chen; Elizabeth A. Freeman; David M. Braun

    2005-01-01

    We investigated the distribution and severity of trees infected with western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N. Jones subsp. tsugense) in an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.)...

  4. Crown dynamics and wood production of Douglas-fir trees in an old-growth forest

    Science.gov (United States)

    H. Roaki Ishii; Stephen C. Sillett; Allyson L. Carroll

    2017-01-01

    Large trees are the most prominent structural features of old-growth forests, which are considered to be globally important carbon sinks. Because of their large size, estimates of biomass and growth of large trees are often based on ground-level measurements (e.g., diameter at breast height, DBH) and little is known about growth dynamics within the crown. As trees...

  5. Fertilizing Douglas-fir forests.

    Science.gov (United States)

    Richard E. Miller; Roger D. Right

    1979-01-01

    This report supplements a slide-tape presentation of the same title. Part I of the report describes the current practice of nitrogen fertilization of Douglas-fir forests in western Washington and Oregon and the effects of this fertilization on tree growth and water quality. Part II discusses factors that affect costs and revenues from investments in forest...

  6. Multi-decadal establishment for single-cohort Douglas-fir forests

    Science.gov (United States)

    James A. Freund; Jerry F. Franklin; Andrew J. Larson; James A. Lutz

    2014-01-01

    The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have...

  7. Douglas-fir tussock moth- and Douglas-fir beetle-caused mortality in a ponderosa pine/Douglas-fir forest in the Colorado Front Range, USA

    Science.gov (United States)

    Jose F. Negron; Ann M. Lynch; Willis C. Schaupp; Vladimir Bocharnikov

    2014-01-01

    An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir...

  8. Architectural analysis of Douglas-fir forests

    NARCIS (Netherlands)

    Kuiper, L.C.

    1994-01-01

    The architecture of natural and semi-natural Douglas-fir forest ecosystems in western Washington and western Oregon was analyzed by various case-studies, to yield vital information needed for the design of new silvicultural systems with a high level of biodiversity, intended for low-input

  9. Temporal change in soil carbon stability at a paired old-growth douglas-fir forest/clear-cut site

    Science.gov (United States)

    Forest ecosystems are estimated to contain one-half of the total terrestrial carbon (C) pool (1146 Pg), with two-thirds of this C (787 Pg) residing in forest soils. Given the magnitude of this C pool, it is critical to understand the effects of forest management practices on soil...

  10. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir in the Oregon Cascades.

    Science.gov (United States)

    Vern P. Yerkes

    1960-01-01

    Land managers often express a need for more complete information about the vegetative cover that develops on cutover areas between harvest of old-growth Douglas-fir (Pseudotsuga menziesii) and establishment of a young-growth forest. The composition and density of this cover frequently determines the management techniques that must be used to...

  11. SPECIES-SPECIFIC PARTITIONING OF SOIL WATER RESOURCES IN AN OLD-GROWTH DOUGLAS-FIR/WESTERN HEMLOCK FOREST

    Science.gov (United States)

    Although tree- and stand-level estimates of forest water use are increasingly common, relatively little is known about partitioning of soil water resources among co-occurring tree species. We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menzies...

  12. Douglas-Fir Tussock Moth- and Douglas-Fir Beetle-Caused Mortality in a Ponderosa Pine/Douglas-Fir Forest in the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    José F. Negrón

    2014-12-01

    Full Text Available An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb. Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir tussock moth defoliation resulted in significant Douglas-fir mortality in the heavily defoliated stands, leading to a change in dominance to ponderosa pine, Pinus ponderosa Lawson. Douglas-fir beetle, Dendroctonus pseudotsuqae Hopkins, populations increased following the defoliation event but caused less mortality, and did not differ between heavily and lightly defoliated stands. Douglas-fir tussock moth-related mortality was greatest in trees less than 15 cm dbh (diameter at 1.4 m above the ground that grew in suppressed and intermediate canopy positions. Douglas-fir beetle-related mortality was greatest in trees larger than 15 cm dbh that grew in the dominant and co-dominant crown positions. Although both insects utilize Douglas-fir as its primary host, stand response to infestation is different. The extensive outbreak of the Douglas-fir tussock moth followed by Douglas-fir beetle activity may be associated with a legacy of increased host type growing in overstocked conditions as a result of fire exclusion.

  13. Overstory response to alternative thinning treatments in young Douglas-fir forests of Western Oregon.

    Science.gov (United States)

    Liane R. Davis; Klaus J. Puettmann; Gabriel F. Tucker

    2007-01-01

    An increase in land dominated by young second-growth Douglas-fir forests in the Pacific Northwest has coincided with heightened concerns over loss of old-growth habitat. In search of options for managing young forests to provide late-successional forest structures, the Young Stand Thinning and Diversity Study was designed to test the effectiveness of modified thinning...

  14. Habitat management for red tree voles in Douglas-fir forests.

    Science.gov (United States)

    M.H. Huff; R.S. Holthausen; K.B. Aubry

    1992-01-01

    The relations between arboreal rodents and trees causes the animals to be particularly sensitive to the effects of timber harvesting.Among arboreal rodents,we consider the redtree vole to be the most vulnerable to local extinctions resulting from the loss or fragmentation of old-growth Douglas-fir forests. Redtree voles are nocturnal,canopy dwelling, and difficult to...

  15. The economic significance of mortality in old-growth Douglas-fir management.

    Science.gov (United States)

    R.O. McMahon

    1961-01-01

    Current mortality in the Douglas-fir subregion, exclusive of catastrophic mortality, approximates a billion feet a year. The Forest Service report "Timber Resources for America's Future" recommended "...utilizing a substantial portion of the unsalvaged mortality loss..." as one means of permanently increasing the Nation's timber supply and...

  16. Fire-mediated pathways of stand development in Douglas-fir/western hemlock forests of the Pacific Northwest, USA

    Science.gov (United States)

    A.J. Tepley; F.J. Swanson; T.A. Spies

    2013-01-01

    Forests dominated by Douglas-fir and western hemlock in the Pacific Northwest of the United States have strongly influenced concepts and policy concerning old-growth forest conservation. Despite the attention to their old-growth characteristics, a tendency remains to view their disturbance ecology in relatively simple terms, emphasizing infrequent, stand-replacing (SR...

  17. LATERAL ROOT DISTRIBUTION OF TREES IN AN OLD-GROWTH DOUGLAS-FIR FOREST INFERRED FROM UPTAKE OF TRACER 15N

    Science.gov (United States)

    Belowground competition for nutrients and water is considered a key factor affecting spatial organization and productivity of individual stems within forest stands, yet there are almost no data describing the lateral extent and overlap of competing root systems. We quantified th...

  18. Stand-level gas-exchange responses to seasonal drought in very young versus old Douglas-fir forests of the Pacific Northwest, USA

    Science.gov (United States)

    Sonia Wharton; Matt Schroeder; Ken Bible; Matthias Falk; Kyaw Tha Paw U

    2009-01-01

    This study examines how stand age affects ecosystem mass and energy exchange response to seasonal drought in three adjacent Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. The sites include two early seral (ES) stands (0 to 15 years old) and an old-growth (OG) (~450 to 500 years old) forest in the Wind River Experimental Forest,...

  19. Increment and mortality in a virgin Douglas-fir forest.

    Science.gov (United States)

    Robert W. Steele; Norman P. Worthington

    1955-01-01

    Is there any basis to the forester's rule of thumb that virgin forests eventually reach an equilibrium where increment and mortality approximately balance? Are we wasting potential timber volume by failing to salvage mortality in old-growth stands?

  20. Simulation of carbon and water budgets of a Douglas-fir forest

    NARCIS (Netherlands)

    Wijk, van M.T.; Dekker, S.C.; Bouten, W.; Kohsiek, W.; Mohren, G.M.J.

    2001-01-01

    The forest growth/hydrology model FORGRO–SWIF, consisting of a forest growth and a soil water model, was applied to quantify the inter-annual variability of the carbon and water budgets of a Douglas-fir forest (Pseudotsuga menziessii (Mirb.) Franco) in The Netherlands. With these budgets, the water

  1. Soil spore bank communities of ectomycorrhizal fungi in endangered Chinese Douglas-fir forests.

    Science.gov (United States)

    Wen, Zhugui; Shi, Liang; Tang, Yangze; Hong, Lizhou; Xue, Jiawang; Xing, Jincheng; Chen, Yahua; Nara, Kazuhide

    2018-01-01

    Chinese Douglas-fir (Pseudotsuga sinensis) is an endangered Pinaceae species found in several isolated regions of China. Although soil spore banks of ectomycorrhizal (ECM) fungi can play an important role in seedling establishment after disturbance, such as in the well-known North American relative (Pseudotsuga menziesii), we have no information about soil spore bank communities in relict forests of Chinese Douglas-fir. We conducted bioassays of 73 soil samples collected from three Chinese Douglas-fir forests, using North American Douglas-fir as bait seedlings, and identified 19 species of ECM fungi. The observed spore bank communities were significantly different from those found in ECM fungi on the roots of resident trees at the same sites (p = 0.02). The levels of potassium (K), nitrogen (N), organic matter, and the pH of soil were the dominant factors shaping spore bank community structure. A new Rhizopogon species was the most dominant species in the spore banks. Specifically, at a site on Sanqing Mountain, 22 of the 57 surviving bioassay seedlings (representing 21 of the 23 soil samples) were colonized by this species. ECM fungal richness significantly affected the growth of bioassay seedlings (R 2  = 0.20, p = 0.007). Growth was significantly improved in seedlings colonized by Rhizopogon or Meliniomyces species compared with uncolonized seedlings. Considering its specificity to Chinese Douglas-fir, predominance in the soil spore banks, and positive effect on host growth, this new Rhizopogon species could play critical roles in seedling establishment and forest regeneration of endangered Chinese Douglas-fir.

  2. Silvicultural research and the evolution of forest practices in the Douglas-fir region.

    Science.gov (United States)

    Robert O. Curtis; Dean S. DeBell; Richard E. Miller; Michael Newton; J. Bradley St. Clair; William I. Stein

    2007-01-01

    Silvicultural practices in the Douglas-fir region evolved through a combination of formal research, observation, and practical experience of forest managers and silviculturists, and changing economic and social factors. This process began more than a century ago and still continues. It has had a great influence on the economic well-being of the region and on the...

  3. Ground-based forest harvesting effects on soil physical properties and Douglas-fir growth.

    Science.gov (United States)

    Adrian Ares; Thomas A. Terry; Richard E. Miller; Harry W. Anderson; Barry L. Flaming

    2005-01-01

    Soil properties and forest productivity can be affected by heavy equipment used for harvest and site preparation but these impacts vary greatly with site conditions and operational practices. We assessed the effects of ground-based logging on soil physical properties and subsequent Douglas-fir [Pseudotsuga menziesii (Mirb) Franco] growth on a highly...

  4. Fire, fuels, and restoration of ponderosa pine-Douglas-fir forests in the Rocky Mountains, USA

    OpenAIRE

    Baker, W. L.; Veblen, T. T.; Sherriff, R. L.

    2007-01-01

    Forest restoration in ponderosa pine and mixed ponderosa pine–Douglas fir forests in the US Rocky Mountains has been highly influenced by a historical model of frequent, low-severity surface fires developed for the ponderosa pine forests of the Southwestern USA. A restoration model, based on this low-severity fire model, focuses on thinning and prescribed burning to restore historical forest structure. However, in the US Rocky Mountains, research on fire history and forest structure, and earl...

  5. Natural regeneration of Douglas-fir and associated species using modified clear-cutting systems in the Oregon Cascades.

    Science.gov (United States)

    Jerry F. Franklin

    1963-01-01

    Clear cutting is the standard harvesting system in old-growth Douglas-fir (Pseudotsuga menziesii) forests in the Pacific Northwest. Usually these clear cuts are in "staggered settings" of 15 to 80 acres with the surrounding stand left uncut to provide seed and serve as a firebreak. However, satisfactory natural regeneration of Douglas-fir...

  6. Increased water deficit decreases Douglas fir growth throughout western US forests.

    Science.gov (United States)

    Restaino, Christina M; Peterson, David L; Littell, Jeremy

    2016-08-23

    Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas fir (Pseudotsuga menziesii) chronologies from 122 locations that represent distinct climate environments in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Using an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas fir growth to decrease throughout its US range.

  7. Two commercial thinnings in century-old Douglas-fir.

    Science.gov (United States)

    Robert W. Steele

    1954-01-01

    As young-growth forests replace old-growth forests as the primary source of Douglas-fir raw material, the technique of managing young stands becomes increasingly important. Managers of young-growth timber need to know whether it is economical and silviculturally feasible to make thinnings in stands that are close to rotation age. Final harvest of some stands of this...

  8. Simulating historical disturbance regimes and stand structures in old-forest ponderosa pine/Douglas-fir forests

    Science.gov (United States)

    Mike Hillis; Vick Applegate; Steve Slaughter; Michael G. Harrington; Helen Smith

    2001-01-01

    Forest Service land managers, with the collaborative assistance from research, applied a disturbance based restoration strategy to rehabilitate a greatly-altered, high risk Northern Rocky Mountain old-forest ponderosa pine-Douglas-fir stand. Age-class structure and fire history for the site have been documented in two research papers (Arno and others 1995, 1997)....

  9. Ecological setting of the Wind River old-growth forest.

    Science.gov (United States)

    David C. Shaw; Jerry F. Franklin; Ken Bible; Jeffrey Klopatek; Elizabeth Freeman; Sarah Greene; Geoffrey G. Parker

    2004-01-01

    The Wind River old-growth forest, in the southern Cascade Range of Washington State, is a cool (average annual temperature, 8.7°C), moist (average annual precipitation, 2223 mm), 500-year-old Douglas-fir-western hemlock forest of moderate to low productivity at 371-m elevation on a less than 10% slope. There is a seasonal snowpack (November-March), and rain-on-snow and...

  10. Mineral cycling in a young Douglas fir forest stand

    International Nuclear Information System (INIS)

    Riekerk, H.

    1978-01-01

    Radiotracers for phosphorus ( 32 P), potassium (substitute 86 Rb), and calcium ( 45 Ca) were used to follow the turnover of nutrients entering the forest floor with rainwash. Phosphorus moved readily through the forest floor to be strongly retained by the acid mineral soil. Considerable phosphorus absorbed by trees was correlated with forest-floor leachate contents and became concentrated in physiologically active tissues. Losses with litterfall and rainwash were nondetectable; this indicated high retention and internal redistribution. Rapid movement toward sinks appeared to be characteristic. In contrast, the larger amounts of calcium added were absorbed by the exchange capacity of the forest floor, with subsequent small but relatively unrestricted movement through the soil and trees. Both calcium and potassium absorption by trees was correlated with mineral-soil leachate contents. Annual potassium mobility fell between that of phosphorus and calcium and appeared to be more dependent on temperature and moisture conditions of the forest ecosystem, with potassium moving rapidly in subcycles during wet periods of the growing season

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

    Directory of Open Access Journals (Sweden)

    Hajnal-Jafari Timea

    2016-08-01

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

  12. Carbon dioxide flux measurements from a coastal Douglas-fir forest floor

    International Nuclear Information System (INIS)

    Drewitt, G.B.

    2002-01-01

    This thesis examined the process that affects the exchange of carbon between the soil and the atmosphere with particular attention to the large amounts of carbon stored in soils in the form of decaying organic matter. This forest floor measuring study was conducted in 2000 at a micro-meteorological tower flux site in a coastal temperature Douglas-fir forest. The measuring study involved half hourly measurements of both carbon dioxide and below-ground carbon dioxide storage. Measurements were taken at 6 locations between April and December to include a large portion of the growing season. Eddy covariance (EC) measurements of carbon dioxide flux above the forest floor over a two month period in the summer and the autumn were compared with forest floor measurements. Below-ground carbon dioxide mixing ratios of soil air were measured at 6 depths between 0.02 to 1 m using gas diffusion probes and a syringe sampling method. Maximum carbon dioxide fluxes measured by the soil chambers varied by a factor of 3 and a high spatial variability in soil carbon dioxide flux was noted. Forest floor carbon dioxide fluxes measured by each of the chambers indicated different sensitivities to soil temperature. Hysteresis in the flux temperature relationship over the year was evident. Reliable below-canopy EC measurements of the forest floor carbon dioxide flux were difficult to obtain because of the every low wind speeds below the forest canopy. The amount of carbon dioxde present in the soil increased rapidly with depth near the surface but less rapidly deeper in the soil. It was suggested that approximately half of the carbon dioxide produced below-ground comes from between the soil surface and the first 0.15 m of depth. Carbon dioxide fluxes from the floor of a Douglas-fir forest were found to be large compared to other, less productive ecosystems

  13. Conversion of SPORL pretreated Douglas fir forest residues into microbial lipids with oleaginous yeasts

    Science.gov (United States)

    Bruce S. Dien; Junyong Zhu; Patricia J. Slininger; Cletus P. Kurtzman; Bryan R. Moser; Patricia J. O' Bryan; Roland Gleisner; Michael A. Cotta

    2016-01-01

    Douglas fir is the dominant commercial tree grown in the United States. In this study Douglas fir residue was converted to single cell oils (SCO) using oleaginous yeasts. Monosaccharides were extracted from the woody biomass by pretreating with sulfite and dilute sulfuric acid (SPORL process) and hydrolyzing using commercial cellulases. A new SPORL process that uses pH...

  14. Thinning shock and response to fertilizer less than expected in young Douglas-fir stand at Wind River Experimental Forest.

    Science.gov (United States)

    Dean S. DeBell; Constance A. Harrington; John. Shumway

    2002-01-01

    Three thinning treatments (thinned to 3.7 by 3.7 m, thinned to 4.3 by 4.3 m, and an unthinned control treatment with nominal spacing averaging 2.6 by 2.6 m) were installed in a 10-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation growing on a low-quality site at the Wind River Experimental Forest in southwest Washington. Two...

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

    Science.gov (United States)

    Robert E. Benson; Joyce A. Schlieter

    1980-01-01

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

  16. Enhancement of Carbon Sequestration in west coast Douglas-fir Forests with Nitrogen Fertilization

    Science.gov (United States)

    Chen, B.; Jassal, R.; Black, A.; Brummer, C.; Spittlehouse, D.; Nesic, Z.

    2008-12-01

    Fertilization is one of the eligible management practices for C sequestering and hence reducing CO2 emissions under Article 3.4 of the Kyoto Protocol. In the coastal regions of British Columbia, which have very little nitrogen (N) deposition from pollution sources owing to their remote location, and soils deficient in N (Hanley et al., 1996), Douglas-fir stands respond to N fertilization (Brix, 1981; Fisher and Binkley, 2000; Chapin et al., 2002). However, a major concern with N fertilization is the potential loss from the soil surface of the highly potent greenhouse gas N2O, and little is known about such losses in N-fertilized forest soils. While it is necessary to determine and quantify the effects of N fertilization on stand C sequestration, it is also important to address environmental concerns by measuring N2O emissions to determine the net greenhouse gas (GHG) global warming potential (GWP). The GWP of N2O is 296 times (100-year time horizon) greater than that of CO2 (Ehhalt and Prather, 2001), yet there is little information on its net radiative forcing as a result of forest fertilization. We report two years of results on the effects of N fertilization in a chronosequence of three Douglas-fir stands (7, 19 and 58 years old, hereafter referred to as HDF00, HDF88 and DF49, respectively) on net C sequestration or net primary productivity measured using the eddy-covariance technique. DF49 (110 ha) and HDF88 (20 ha) were aerially fertilized with urea at 200 kg N ha-1 on Jan 13 and Feb 17, 2007, respectively, while due to its young age and competing understory, fertilizer to HDF00 (5 ha) was manually applied at 80 g urea/tree (60 kg N ha-1) along the tree drip line on Feb 13-14, 2007. Additionally, we calculate the net change in GHG GWP resulting from fertilization of DF49 by accounting for N2O emissions and energy costs of fertilizer production, transport, and application. We also compare polymer-coated slow-release urea (Environmentally Smart Nitrogen (ESN

  17. Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  18. Tree water storage and its diurnal dynamics related to sap flow and changes in stem volume in old-growth Douglas-fir trees.

    Science.gov (United States)

    Cermák, Jan; Kucera, Jiri; Bauerle, William L; Phillips, Nathan; Hinckley, Thomas M

    2007-02-01

    Diurnal and seasonal tree water storage was studied in three large Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees at the Wind River Canopy Crane Research site. Changes in water storage were based on measurements of sap flow and changes in stem volume and tissue water content at different heights in the stem and branches. We measured sap flow by two variants of the heat balance method (with internal heating in stems and external heating in branches), stem volume with electronic dendrometers, and tissue water content gravimetrically. Water storage was calculated from the differences in diurnal courses of sap flow at different heights and their integration. Old-growth Douglas-fir trees contained large amounts of free water: stem sapwood was the most important storage site, followed by stem phloem, branch sapwood, branch phloem and needles. There were significant time shifts (minutes to hours) between sap flow measured at different positions within the transport system (i.e., stem base to shoot tip), suggesting a highly elastic transport system. On selected fine days between late July and early October, when daily transpiration ranged from 150 to 300 liters, the quantity of stored water used daily ranged from 25 to 55 liters, i.e., about 20% of daily total sap flow. The greatest amount of this stored water came from the lower stem; however, proportionally more water was removed from the upper parts of the tree relative to their water storage capacity. In addition to lags in sap flow from one point in the hydrolic pathway to another, the withdrawal and replacement of stored water was reflected in changes in stem volume. When point-to-point lags in sap flow (minutes to hours near the top and stem base, respectively) were considered, there was a strong linear relationship between stem volume changes and transpiration. Volume changes of the whole tree were small (equivalent to 14% of the total daily use of stored water) indicating that most stored water came from

  19. Five-Year Impacts of Swiss Needle Cast on Douglas-fir in Interior Forests of Oregon, USA

    Directory of Open Access Journals (Sweden)

    FILIP, Gregory

    2007-01-01

    Full Text Available In 2001 and 2006, we examined 590 Douglas-firs in 59 stands age 10-23 years in the northern Cascade Mountain foothills in Oregon, USA. Mean 5-year-dbh growth was 6.1 cm and total-height growth was 3.6 m. Mean needle-retention index increased by 3.4 over 5 years, and mid-crown retention increased by 1.2 years. Mean percentages of stomata occluded by pseudothecia of Phaeocryptopus gaeumannii were 13.6% for 2000-(2-year-old needles and 1.7% for 2001-(1-year-old needles sampled in 2002, and 13.3% for 2004 (2-year-old needles sampled in 2006. Mean crown-length to sapwood-area ratio was 5.2 cm/cm2 in 2006. There were poor correlations (R2 <0.3 among all variables except for a moderate correlation between stand elevation and either 2000-stomata occluded (R2 = 0.43 or 2004-stomata occluded (R2 = 0.50, where there were fewer pseudothecia at the higher elevations. Either 5 years is not enough time to evaluate the affects of Swiss needle cast on Douglas-fir growth in the Oregon Cascades or there was no significant effect of Swiss needle cast during the latest outbreak on Douglas-fir growth. Based on our results and their interpretation, forest managers may need not alter their current practices in the northern Oregon Cascades, and managing a mix of Douglas-fir and western hemlock at lower elevations and noble fir at higher elevations will help offset any future stand-growth declines due to Swiss needle cast.

  20. Nitrogen, corn, and forest genetics: the agricultural yield strategy-implications for Douglas-fir management.

    Science.gov (United States)

    Roy R. Silen

    1982-01-01

    Agricultural yield strategy simply aims to increase number of grain bearing stalks per acre. Forestry strategies look to thinning, fertilizer, and genetics, each to provide gains. The agricultural strategies applied to Douglas-fir appear to be impractical for long rotations. Concern is expressed for commitments to perpetual inputs of materials and energy to keep a...

  1. Influences of climate, fire, and topography on contemporary age structure patterns of Douglas-fir at 205 old forest sites in western Oregon

    Science.gov (United States)

    Nathan J. Poage; Peter J. Weisberg; Peter C. Impara; John C. Tappeiner; Thomas S. Sensenig

    2009-01-01

    Knowledge of forest development is basic to understanding the ecology, dynamics, and management of forest ecosystems. We hypothesized that the age structure patterns of Douglas-fir at 205 old forest sites in western Oregon are extremely variable with long and (or) multiple establishment periods common, and that these patterns reflect variation in regional-scale climate...

  2. Soil properties in old-growth Douglas-fir gaps in the western Cascade Mountains of Oregon

    Science.gov (United States)

    Robert P. Griffiths; Andrew N. Gray; Thomas A. Spies

    2010-01-01

    This study had three objectives: (1) to determine if there are correlations between aboveground vegetation and belowground soil properties within large 50-m-diameter gaps, (2) to determine how large gaps influence forest soils compared with nongap soils, and (3) to measure the effects of differently sized gaps on gap soils. Circular canopy gaps were created in old-...

  3. Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

  4. Tree microhabitat structures as indicators of biodiversity in Douglas-fir forests of different stand ages and management histories in the Pacific Northwest, U.S.A.

    Science.gov (United States)

    Alexa K. Michel; Susanne. Winter

    2009-01-01

    In this study, microhabitat structures in Douglas-fir (Pseudotsuga menziesii) forests were defined and their frequency and abundance in natural stands and stands of varying active management histories and stand ages was compared. Indicator microhabitat structures for natural forests were determined and the relationship of the abundance of...

  5. Using sulfite chemistry for robust bioconversion of Douglas-fir forest residue to bioethanol at high titer and lignosulfonate: A pilot-scale evaluation

    Science.gov (United States)

    J.Y. Zhu; M. Subhosh Chandra; Feng Gu; Roland Gleisner; J.Y. Zhu; John Sessions; Gevan Marrs; Johnway Gao; Dwight Anderson

    2015-01-01

    This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir forest harvest residue, an underutilized forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid–liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the...

  6. SEASONAL PATTERNS AND VERTICAL PROFILE OF SOIL WATER UPTAKE AND UTILIZATION BY YOUNG AND OLD DOUGLAS-FIR AND PONDEROSA PINE FORESTS

    Science.gov (United States)

    Water availability has a strong influence on the distribution of forest tree species across the landscape. However, we do not understand how seasonal patterns of water utilization by tree species are related to their drought tolerance. In the Pacific Northwest, Douglas-fir occu...

  7. Growth and yield of all-aged Douglas-fir -- western hemlock forest stands: a matrix model with stand diversity effects.

    Science.gov (United States)

    Jingjing Liang; Joseph Buonglorno; Robert A. Monserud

    2005-01-01

    A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) -- western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters...

  8. Less than 50% nitrogen retention 1-year after high N additions to Pacific Northwest Douglas-fir forests

    Science.gov (United States)

    Michelsen-Correa, S.; Harrison, R. B.

    2017-12-01

    In Pacific Northwest forests, N is known to be a limiting nutrient particularly in Douglas-fir (Pseudotsuga menziesii) ecosystems. Fertilizers are commonly applied to increase productivity in commercially managed forests. Despite known N limitations, Douglas-fir uptake of applied fertilizers is typically low and highly variable depending on environmental site conditions of a particular forest. We measured N recovery within a 1-year time frame at five sites using a fertilizer enriched in 15N as a tracer. Comparisons were also made between Enhanced Efficiency Fertilizers (EEFs) and an unformulated urea fertilizer to determine if N recovery is improved with fertilizers designed to limit volatile losses of ammonia. Retention was low across all sites and fertilizer types with a mean of 39.0% recovered after 1-year. The largest fertilizer pool was the top 20cm of mineral soil. The use of EFFs as a management tool to improve N use efficiency at the five sites in our study is not supported by our results as no significant differences in total 1-year N recovery or tree uptake of N were observed between treatments. The low N recovery after 1-year but simultaneous increases in above ground biomass support a model of N loss where the ecosystem can continue to accumulate biomass with simultaneous leaching and gaseous losses of N. This conclusion contrasts with the commonly held assumption that fertilization of N limited Douglas-fir forests, should yield negligible losses of N and high recovery of the applied fertilizer. Additionally, we conclude that management decisions regarding fertilizer use efficiency and the benefits of fertilization need to be site specific due to the variable N recovery rates based on site factors as opposed to fertilizer treatment type. Finally, despite differences in the size of available soil N pools the amount of N recovered in the above group pools (i.e. bole wood and foliage) were not significantly different between sites. N uptake by the plants

  9. NEEDLE ANATOMY CHANGES WITH INCREASING TREE AGE IN DOUGLAS FIR

    Science.gov (United States)

    Morphological differences between old growth and sapling (Pseudotsuga menziesii, (Mirb.) Franco) Douglas fir trees may extend to differences in needle anatomy. We used microscopy with image analysis to compare and quantify anatomical parameters in cross-sections of previous year...

  10. Interactions of predominant insects and diseases with climate change in Douglas-fir forests of western Oregon and Washington, U.S.A.

    Science.gov (United States)

    Agne, Michelle C; Beedlow, Peter A; Shaw, David C; Woodruff, David R; Lee, E Henry; Cline, Steven P; Comeleo, Randy L

    2018-02-01

    Forest disturbance regimes are beginning to show evidence of climate-mediated changes, such as increasing severity of droughts and insect outbreaks. We review the major insects and pathogens affecting the disturbance regime for coastal Douglas-fir forests in western Oregon and Washington State, USA, and ask how future climate changes may influence their role in disturbance ecology. Although the physiological constraints of light, temperature, and moisture largely control tree growth, episodic and chronic disturbances interacting with biological factors have substantial impacts on the structure and functioning of forest ecosystems in this region. Understanding insect and disease interactions is critical to predicting forest response to climate change and the consequences for ecosystem services, such as timber, clean water, fish and wildlife. We focused on future predictions for warmer wetter winters, hotter drier summers, and elevated atmospheric CO 2 to hypothesize the response of Douglas-fir forests to the major insects and diseases influencing this forest type: Douglas-fir beetle, Swiss needle cast, black stain root disease, and laminated root rot. We hypothesize that 1) Douglas-fir beetle and black stain root disease could become more prevalent with increasing, fire, temperature stress, and moisture stress, 2) future impacts of Swiss needle cast are difficult to predict due to uncertainties in May-July leaf wetness, but warmer winters could contribute to intensification at higher elevations, and 3) laminated root rot will be influenced primarily by forest management, rather than climatic change. Furthermore, these biotic disturbance agents interact in complex ways that are poorly understood. Consequently, to inform management decisions, insect and disease influences on disturbance regimes must be characterized specifically by forest type and region in order to accurately capture these interactions in light of future climate-mediated changes.

  11. Vine maple (Acer circinatum) clone growth and reproduction in managed and unmanaged coastal Oregon douglas-fir forests

    Science.gov (United States)

    O'Dea, Mary E.; Zasada, John C.; Tappeiner, John C.

    1995-01-01

    Vine maple (Acer circinatum Pursh.) clone development, expansion, and regeneration by seedling establishment were studied in 5-240 yr old managed and unmanaged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in coastal Oregon. Stem length, number of stems, and crown area were all significantly (P @10 m long and basal sprouts 1-2 m long; some stems had been pinned to the forest floor by fallen trees or branches and had layered. In stands >120 yr in age, clones were often quite complex, composed of several decumbent stems each of which connected the ramets of 1-10 new aerial stems. Vine maple clone expansion occurs by the layering of long aerial stems. Over 95% of the layered stems we observed had been pinned to the forest floor by fallen debris. Unsevered stems that we artificially pinned to the forest floor initiated roots within 1 yr. Thinning may favor clonal expansion because fallen slash from thinning often causes entire clones to layer, not just individual stems. Clonal vine maple seed production and seedling establishment occurred in all stages of stand development except dense, young stands following crown closure. There were more seedlings in thinned stands than in unthinned stands and in unburned clearcuts than in burned clearcuts.

  12. Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  13. Thinning of young Douglas-fir forests decreases density of northern flying squirrels in the Oregon Cascades

    Science.gov (United States)

    Manning, Tom; Hagar, Joan C.; McComb, Brenda C.

    2012-01-01

    Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to measure the impact of commercial thinning on northern flying squirrels have mostly addressed short-term effects (2–5 years post-thinning) and the few published studies of longer-term results have been contradictory. We measured densities of northern flying squirrels 11–13 years after thinning of young (55–65 years) Douglas-fir forest stands in the Cascade Range of Oregon, as part of the Young Stand Thinning & Diversity Study. The study includes four replicate blocks, each consisting of an unthinned control stand and one stand each of the following thinning treatments: Heavy Thin; Light Thin; and Light Thin with Gaps. Thinning decreased density of northern flying squirrels, and squirrel densities were significantly lower in heavily thinned stands than in more lightly thinned stands. Regression analysis revealed a strong positive relationship of flying squirrel density with density of large (>30 cm diameter) standing dead trees and a negative relationship with percent cover of low understory shrubs. Maintaining sufficient area and connectivity of dense, closed canopy forest is recommended as a strategy to assure that long-term goals of promoting late-seral structure do not conflict with short-term habitat requirements of this important species.

  14. Stand-Level Gas-Exchange Responses to Seasonal Drought in Very Young Versus Old Douglas-fir Forests of the Pacific Northwest, USA

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Schroeder, M; Bible, K; Falk, M; Paw U, K T

    2009-02-23

    This study examines how stand age affects ecosystem mass and energy exchange response to seasonal drought in three adjacent Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests. The sites include two early seral stands (ES) (0-15 years old) and an old-growth (OG) ({approx} 450-500) forest in the Wind River Experiment Forest, Washington, USA. We use eddy covariance flux measurements of carbon dioxide (F{sub NEE}), latent energy ({lambda}E) and sensible heat (H) to derive evapotranspiration rate (E{sub T}), bowen ratio ({beta}), water use efficiency (WUE), canopy conductance (G{sub c}), the Priestley-Taylor coefficient ({alpha}) and a canopy decoupling factor ({Omega}). The canopy and bulk parameters are examined to see how ecophysiological responses to water stress, including changes in available soil water ({theta}{sub r}) and vapor pressure deficit ({delta}e) differ among the two forest successional-stages. Despite very different rainfall patterns in 2006 and 2007, we observed distinct successional-stage relationships between E{sub T}, {alpha}, and G{sub c} to {delta}e and {theta}{sub r} during both years. The largest stand differences were (1) higher morning G{sub c} (> 10 mm s{sup -1}) at the OG forest coinciding with higher CO{sub 2} uptake (F{sub NEE} = -9 to -6 {micro}mol m{sup -2} s{sup -1}) but a strong negative response in G{sub c} to moderate {delta}e later in the day and a subsequent reduction in E{sub T}, and (2) higher E{sub T} at the ES stands because midday canopy conductance did not decrease until very low water availability levels (<30%) were reached at the end of the summer. Our results suggest that early seral stands are more likely than mature forests to experience declines in production if the summer drought becomes longer or intensifies because water conserving ecophysiological responses were only observed at the very end of the seasonal drought period in the youngest stands.

  15. Relationship between canopy structure, microclimate, and Swiss needle cast severity among different ages of Douglas-fir forests

    Science.gov (United States)

    Swiss needle cast (SNC) is an endemic disease of Douglas-fir caused by Phaeocryptopus gaeumannii. The fungus infects newly emerged needles between May and August. As the fungus develops, its fruiting bodies (pseudothecia) block the stomata and inhibit gas exchange, reducing the p...

  16. Fingerprints of a forest fungus: Swiss needle cast, carbon isotopes, carbohydrates, and growth in Douglas-fir

    Science.gov (United States)

    Andrea Watts; Frederick Meinzer; Brandy J. Saffell

    2014-01-01

    Swiss needle cast is caused by a fungus native to the Pacific Northwest. Its host is Douglas-fir, an iconic evergreen tree in the region. The fungus does not kill its host, but it adversely affects the tree's growth. The fungal fruiting bodies block the stomata, small openings on the underside of the needle where carbon dioxide, water vapor, and other gases are...

  17. Timber supply in the Pacific Northwest: managing for economic and ecological values in Douglas-fir forest.

    Science.gov (United States)

    R.O. Curtis; A.B. Carey

    1996-01-01

    The Douglas-fir region of western Washington and Oregon and coastal British Columbia contains the most productive forestlands in North America. Yet disagreement among user groups and conflicting goals, policies, and laws have nearly paralyzed timber management on federal lands and greatly increased costs and complexity of management on nonfederal lands. Constructive...

  18. Douglas-Fir Tussock Moth

    Science.gov (United States)

    Boyd E. Wickman; Richard R. Mason; Galen C. Trostle

    1981-01-01

    The Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) is an important defoliator of true firs and Douglas-fir in Western North America. Severe tussock moth outbreaks have occurred in British Columbia, Idaho, Washington, Oregon, Nevada, California, Arizona, and New Mexico, but the area subject to attack is more extensive

  19. When the douglas-firs were counted: The beginning of the Forest Survey

    Science.gov (United States)

    Ivan Doig

    1976-01-01

    The wonders which Phil Briegleb remembered from that stint of work - the dark green spill of forest from ridgeline to valley floor, the colonnade of giant boles crowding acre upon acre, the Depression-staving paycheck earned by sizing up this big timber - may have been grand, all right, but no more so than the language which spelled out the project. The Forest Survey...

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

    Science.gov (United States)

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

  1. Songbird response to alternative forest density management in young Douglas-fir stands

    Science.gov (United States)

    Joan C. Hagar

    2013-01-01

    Th inning has been increasingly used in the Pacifi c Northwest to restore structural and biological diversity to densely-stocked young- to mid-aged forests that have been previously intensively managed for timber production. In the short term, thinning promotes development of understory vegetation, which in turn can increase habitat diversity for wildlife, particularly...

  2. The role of organic matter as a source of nitrogen in Douglas-fir forest soils.

    Science.gov (United States)

    Robert F. Tarrant

    1948-01-01

    The organic material supplied the forest soil by deposits of needles, deadwood and roots, and soil insect remains, decomposes to form humus, defined as the plant and animal residues of the soil, fresh surface litter excluded, which are undergoing evident decomposition (2). This decomposition is necessary before the nutrient elements contained in the organic litter can...

  3. Simulation of forest growth, applied to douglas fir stands in the Netherlands

    NARCIS (Netherlands)

    Mohren, G.M.J.

    1987-01-01

    Forest growth in relation to weather and soils is studied using a physiological simulation model. Growth potential depends on physiological characteristics of the plant species in combination with ambient weather conditions (mainly temperature and incoming radiation). For a given site, growth may be

  4. Trapping Douglas-fir beetle (Dendroctonus pseudotsugae) with pheromone baited multiple-funnel traps does not reduce Douglas-fir (Pseudotsuga menziesii) mortality

    Science.gov (United States)

    R.A. Progar; N. Sturdevant; M.J. Rinella

    2010-01-01

    Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (DFB) causes considerable mortality to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North American forests. We evaluated the use of semiochemical-baited multiple-funnel traps for the protection of small, high-value stands of trees, such as those occurring...

  5. Pretreatment of forest residues of Douglas fir by wet explosion for enhanced enzymatic saccharification.

    Science.gov (United States)

    Biswas, Rajib; Teller, Philip J; Ahring, Birgitte K

    2015-09-01

    The logging and lumbering industry in the Pacific Northwest region generates huge amount of forest residues, offering an inexpensive raw material for biorefineries. Wet explosion (WEx) pretreatment was applied to the recalcitrant biomass to optimize process conditions including temperature (170-190 °C), time (10-30 min), and oxygen loading (0.5-7.5% of DM) through an experimental design. Optimal pH for enzymatic hydrolysis of the optimized samples and a complete mass balance have been evaluated. Results indicated that cellulose digestibility improved in all conditions tested with maximum digestibility achieved at 190 °C, time 30 min, and oxygen loading of 7.5%. Glucose yield at optimal pH of 5.5 was 63.3% with an excellent recovery of cellulose and lignin of 99.9% and 96.3%, respectively. Hemicellulose sugars recovery for xylose and mannose was found to be 69.2% and 76.0%, respectively, indicating that WEx is capable of producing relative high sugar yield even from the recalcitrant forest residues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A perfect storm: multiple stressors interact to drive postfire regeneration failure of lodgepole pine and Douglas-fir forests in Yellowstone

    Science.gov (United States)

    Hansen, W. D.; Braziunas, K. H.; Rammer, W.; Seidl, R.; Turner, M. G.

    2017-12-01

    Twenty-first century forests will experience increased stress as environmental conditions and disturbance regimes change. Whether forests retain their structure or transitions to alternate states, particularly when affected by multiple stressors, remains unresolved. Subalpine forests in Yellowstone National Park, WY experience large severe wildfires, and postfire-tree regeneration is necessary to assure resilience. Drying is projected, causing frequent larger wildfires that could reduce seed supply and drought that could constrain postfire-seedling establishment. We asked what combinations of warming-drying conditions, increased fire frequency, and increased burned-patch size cause postfire tree-regeneration failure in Yellowstone? We conducted a simulation experiment to identify combinations of fire frequency, fire size, postfire climate, substrate type, and elevation where lodgepole-pine and Douglas-fir regeneration failed. We expected postfire densities to be reduced if burned-patch sizes exceeded effective dispersal distance, sequential fires burned before trees reached reproductive maturity, or drought occurred after fire. We also expected regeneration failure only where multiple stressors occurred simultaneously at low elevation or on poor substrates.Douglas-fir stands were most vulnerable to regeneration failure. 98% of simulated Douglas-fir stands located in the middle of large burned patches failed to regenerate 30 years post fire. Lodgepole-pine stands in the middle of large burned patches failed to regenerate if they were also located at low elevations (93%) or at higher elevations on soils with poor water retention (73%). Stands of serotinous lodgepole (i.e., trees with closed cones that open when heated) also failed to regenerate if fire recurred before trees were reproductively mature (82%). Drought constrained postfire regeneration, yet, enhanced establishment due to release from cold-temperatures during mid-to-late 21st century often outweighed

  7. Comparison between mycocenosis living in forest of Cestnut reforested with Douglas Fir; Confronto tra micocenosi presenti nei boschi di latifoglie e rimboschimenti di Douglasia

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, A.; Serra, F. [ENEA, Centro Ricerche Brasimone, Bologna (Italy). Dipt. Ambiente; Dalla Valle, E.; Govi, G. [Bologna, Univ. (Italy). Dipt. di Protezione e Valorizzazione Agroalimentare. Centro di Micologia

    1997-05-01

    In this technical report the results of a first mycological research carried out from 1989 to 1990 in Brasimone in the high Bolognan Appennines (Northern Italy) are shown. The study was taken up by making a comparison between the fungus community living in forest plots with different vegetation; in particular, the mycocenosis of plots reforested with Douglas Fir (Pseudotsuga (Mirb.) Franco) with those of Beech (Fagus sylvatica L.) and Cestnut (Castanea sativa Mill.) woods were compared. The results show that the specific richness clearly decreases form mixed broad-leaved forest (90 species) to the mono specific plantation of P. menziesii (41 species). Particularly in the artificial plantation with exotic trees, there are few symbiont species while the saprophytic wood and litter fungi abound in relationship with the large bulk of undecomposed vegetable material present in these habitats.

  8. Exploring Old Growth Forests: A Teacher's Manual.

    Science.gov (United States)

    Lemieux, Chris; Powers, Jennene; Quinby, Peter; Schultz, Caroline; Stabb, Mark

    "Exploring Old Growth Forests" is an Ontario (Canada) program that provides secondary students with hands-on experiences in old growth forests. Activity-based and student-centered, the program aims to develop student awareness of the importance of old growth forests and the need to conserve them. This manual provides teachers with…

  9. Light thinning in century-old Douglas-fir.

    Science.gov (United States)

    Robert W. Steele

    1948-01-01

    A stand-improvement study in century-old Douglas-fir at the Wind River Experimental Forest provides an example of a commercial thinning that gave a substantial intermediate harvest, salvaged considerable material that would have been lost through mortality, greatly increased the net growth rate, and improved the general vigor of the stand, leaving the forest in a more...

  10. Reproduction following small group cuttings in virgin Douglas-fir.

    Science.gov (United States)

    Norman P. Worthington

    1953-01-01

    Quick and adequate regeneration of Douglas-fir forests as they are harvested is a major forest management problem in the Puget Sound region. Clear-cutting by staggered settings has not always resulted in adequate regeneration even where no part of the area is more than one-fourth mile from a seed source. Single tree selection, experimented with extensively, has many...

  11. Response of individual Douglas-fir trees to release.

    Science.gov (United States)

    Donald L. Reukema

    1961-01-01

    To evaluate effects of different degrees of release on individual Douglas-fir trees, a study was started in 1952 in a 41-year-old, site IV stand at the Wind River Experimental Forest. A remeasurement at the end of four growing seasons showed that dominants respond more quickly and positively to the removal of competing trees than codominants or intermediates. A second...

  12. Impact of Nitrogen Fertilization on Forest Carbon Sequestration and Water Loss in a Chronosequence of Three Douglas-Fir Stands in the Pacific Northwest

    Directory of Open Access Journals (Sweden)

    Xianming Dou

    2015-05-01

    Full Text Available To examine the effect of nitrogen (N fertilization on forest carbon (C sequestration and water loss, we used an artificial neural network model to estimate C fluxes and evapotranspiration (ET in response to N fertilization during four post-fertilization years in a Pacific Northwest chronosequence of three Douglas-fir stands aged 61, 22 and 10 years old in 2010 (DF49, HDF88 and HDF00, respectively. Results showed that N fertilization increased gross primary productivity (GPP for all three sites in all four years with the largest absolute increase at HDF00 followed by HDF88. Ecosystem respiration increased in all four years at HDF00, but decreased over the last three years at HDF88 and over all four years at DF49. As a result, fertilization increased the net ecosystem productivity of all three stands with the largest increase at HDF88, followed by DF49. Fertilization had no discernible effect on ET in any of the stands. Consequently, fertilization increased water use efficiency (WUE in all four post-fertilization years at all three sites and also increased light use efficiency (LUE of all the stands, especially HDF00. Our results suggest that the effects of fertilization on forest C sequestration and water loss may be associated with stand age and fertilization; the two younger stands appeared to be more efficient than the older stand with respect to GPP, WUE and LUE.

  13. Disturbances and structural development of natural forest ecosystems with silvicultural implications, using Douglas-fir forests as an example.

    Science.gov (United States)

    J.F. Franklin; T.A. Spies; R.V. Pelt; A.B. Carey; D.A. Thornburgh; D.R. Berg; D.B. Lindenmayer; M.E. Harmon; W.S. Keeton; D.C. Shaw; K. Bible; J. Chen

    2002-01-01

    Forest managers need a comprehensive scientific understanding of natural stand development processes when designing silvicultural systems that integrate ecological and economic objectives, including a better appreciation of the nature of disturbance regimes and the biological legacies, such as live trees, snags, and logs, that they leave behind. Most conceptual forest...

  14. Structure and Composition of Old-Growth and Unmanaged Second-Growth Riparian Forests at Redwood National Park, USA

    Directory of Open Access Journals (Sweden)

    Christopher R. Keyes

    2014-02-01

    Full Text Available Restoration of second-growth riparian stands has become an important issue for managers of redwood (Sequoia sempervirens [D. Don] Endl. forest reserves. Identifying differences between old-growth and second-growth forest vegetation is a necessary step in evaluating restoration needs and targets. The objective of this study was to characterize and contrast vegetation structure and composition in old-growth and unmanaged second-growth riparian forests in adjacent, geomorphologically similar watersheds at Redwood National Park. In the old-growth, redwood was the dominant overstory species in terms of stem density, basal area, and importance values. Second-growth was dominated by red alder (Alnus rubra Bong., Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco, and redwood. Understory species were similar in both forests, with several key differences: Oxalis oregana Nutt. and Trillium ovatum Pursh had greater importance values in the old-growth, and Vaccinium parvifolium Sm., Dryopteris spp. and sedges Carex spp. had greater importance values in the second-growth. Notable differences in structure and composition suggest that restoration practices such as thinning could expedite the acquisition of old-growth characteristics in second-growth riparian forests.

  15. Flight periodicity of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae: Scolytinae) in Colorado, U.S.A

    Science.gov (United States)

    Jose F. Negron; Willis C. Schaupp; Lee Pederson

    2011-01-01

    There are about 500 species of bark beetles (Coleoptera: Curculionidae: Scolytinae) in the United States (Wood 1982). A number of them are important disturbance agents in forested ecosystems, occasionally creating large tracts of dead trees. One eruptive species is the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, which utilizes Douglas-fir, Pseudotsuga...

  16. Deterioration of beetle-killed Douglas-fir in Oregon and Washington: a summary of findings to date.

    Science.gov (United States)

    Ernest Wright; K.H. Wright

    1954-01-01

    In 1952 and 1953 cooperative research was conducted by the Pacific Northwest Forest Experiment Station and the Research Department of Weyerhaeuser Timber Company to obtain information concerning the rate of deterioration of beetle-killed Douglas-fir. The study was prompted by an outbreak of the Douglas-fir beetle that developed in 1951 and has since killed an estimated...

  17. Graft union formation in Douglas-fir.

    Science.gov (United States)

    D.L. Copes

    1969-01-01

    Greenhouse-grown Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) graft unions were examined between 2 and 84 days after grafting. Room temperature was maintained at 60-70 F throughout the growing season. In most respects grafts of Douglas-fir followed development patterns previously reported for spruce and pine grafts, but specific differences...

  18. A preliminary study of the deterioration of alder and Douglas-fir chips in outdoor piles.

    Science.gov (United States)

    Ernest. Wright

    1954-01-01

    In the fall of 1952, E. E. Matson of the Pacific Northwest Forest and Range Experiment Station learned that the Fir-Tex Insulating Board Company bf St. Helens, Oregon was considering mixing alder with Douglas-fir chips for outside storage. Since alder heartwood i s more susceptible to decay than that of Douglas-fir, the question arose whether mixing the two might...

  19. Turbulence considerations for comparing ecosystem exchange over old-growth and clear-cut stands for limited fetch and complex canopy flow conditions

    Science.gov (United States)

    Sonia Wharton; Matt Schroeder; Kyaw Tha Paw U; Matthias Falk; Ken Bible

    2009-01-01

    Carbon dioxide (CO2), water vapor, and energy fluxes were measured using eddy covariance (EC) methodology over three adjacent evergreen forests in southern Washington State to identify stand-level age-effects on ecosystem exchange. The sites represent Douglas-fir forest ecosystems at two contrasting successional stages: old-growth (OG) and early...

  20. Interactions of predominant insects and diseases with climate change in Douglas-fir forests of Western Oregon and Washington, USA

    Science.gov (United States)

    Forest disturbance regimes are beginning to show evidence of climate-mediated shifts associated with global climate change, and these patterns will likely continue due to continuing changes in environmental conditions. Tree growth is controlled by the physiological constraints o...

  1. Depression of belowground respiration is more pronounced than enhancement of photosynthesis during the first year after nitrogen fertilization of a mature Pacific Northwest Douglas-fir forest

    Science.gov (United States)

    Chen, B.; Black, T. A.; Jassal, R.; Nesic, Z.; Bruemmer, C.

    2008-05-01

    Nitrogen (N) additions to forest have shown variable effects on both respiration and photosynthesis. With increasing rates of anthropogenic N deposition, there is a strong need to understand the ecosystem response to N inputs. We investigated how N fertilization affects the ecosystem carbon (C) balance of a 57-year-old coast Douglas-fir stand in British Columbia, Canada, based on eddy-covariance (EC) and soil-chamber (fertilized and control plots) measurements and process-based modeling. The stand was fertilized by helicopter with urea at 200 kg N ha-1 in January 2007. A land surface model (Ecosystem Atmosphere Simulation Scheme, EASS) was combined with an ecosystem model (Boreal Ecosystem Productivity Simulator, BEPS) and a coupled C and N subroutine was incorporated into the integrated EASS-BEPS model in this study. This half-hourly time step model was run continuously for the period from 2001 to 2007 in two scenarios: with and without fertilization. Modeled C fluxes without fertilization [net ecosystem productivity (NEP), gross primary productivity (GPP), ecosystem respiration (Re) and belowground respiration (Rs)] agreed well with EC and soil chamber measurements over diurnal, seasonal and annual time scales for 2001 to 2006; while simulated NEP, GPP, Re and Rs with fertilization reasonably followed EC and chamber measurements in 2007 (545 vs. 520, 2163 vs. 2155, 1618 vs. 1635, and 920 vs. 906 g C m-2 yr-1, respectively). Comparison of EC-determined C fluxes in 2007 with model simulations without fertilization suggests that annual Re decreased by 6.7% (1635 vs. 1752 g C m-2), gross primary productivity (GPP) increased by 6.8% (2155 vs. 2017 g C m-2), and annual NEP increased by 96.2% (520 vs. 265 g C m-2) due to fertilization. The modeled reduction in Rs (9.6%, comparing modeled values without and with fertilization: 1008 vs. 920 g C m-2 yr-1) is consistent with that measured using the soil chambers (~11.5%, comparing CO2 effluxes from control and fertilized

  2. Sudden oak death-caused changes to surface fuel loading and potential fire behavior in Douglas-fir-tanoak forests

    Science.gov (United States)

    Y.S. Valachovic; C.A. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

    2011-01-01

    We compared stand structure and fuel loading in northwestern California forests invaded by Phytophthora ramorum, the cause of sudden oak death, to assess whether the continued presence of this pathogen alters surface fuel loading and potential fire behavior in ways that may encumber future firefighting response. To attempt to account for these...

  3. Douglas-fir displays a range of growth responses to ...

    Science.gov (United States)

    Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC using time series intervention analysis of intra-annual tree-ring width data collected at nine forest stands in western Oregon, USA. The effects of temperature and SNC were similar in importance on tree growth at all sites. Previous-year DPD during the annual drought period was a key factor limiting growth regionally. Winter temperature was more important at high elevation cool sites, whereas summer temperature was more important at warm and dry sites. Growth rate increased with summer temperature to an optimum (Topt) then decreased at higher temperatures. At drier sites, temperature and water affected growth interactively such that Topt decreased with decreasing summer soil moisture. With climate change, growth rates increased at high elevation sites and declined at mid-elevation inland sites since ~1990. Growth response to climate is masked by SNC regionally. We conclude that as temperature rises and precipitation patterns shift towards wetter winters and drier summers, Douglas-fir will experience greater temperature and water stress and an increase in severity of SNC. By the end of the 21st century, climate models predict hotter, drier summers and warmer, wetter winters in the Pac

  4. Soil Greenhouse Gas Fluxes in a Pacific Northwest Douglas-Fir Forest: Results from a Soil Fertilization and Biochar Addition Experiment

    Science.gov (United States)

    Hawthorne, I.; Johnson, M. S.; Jassal, R. S.; Black, T. A.

    2013-12-01

    Rising atmospheric concentrations of greenhouse gases (GHGs), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), linked to current climate change has stimulated a scientific response to provide robust accounting of sources and sinks of these gases. There is an urgent need to increase awareness of land management impacts on GHG flux dynamics to facilitate the development of management strategies that minimize GHG emissions. Biochar (pyrolyzed organic matter) has been identified as a strategy to reduce net GHG fluxes from soils. This is due to its potential to sequester large amounts of carbon for significant time periods, as well as its modification of biotic and abiotic soil conditions, which in turn can alter the GHG balance. This study describes the effect of biochar and urea-N application on soil surface CO2, CH4 and N2O fluxes in a Pacific Northwest Douglas-fir forest on Vancouver Island, BC, Canada (49o 52' N, 125o 20' W). We used a randomized complete-block design with four replicates of the following treatments: i) control, ii) 5 Mg ha-1 biochar surface application, iii) 200 kg N ha-1 urea pellets surface application, and iv) 5 Mg ha-1 biochar plus 200 kg N ha-1 urea. Soil GHG flux measurements were made biweekly for two years beginning in September 2011 using a non-steady-state non-flow through chamber technique. Biochar was added in February 2012, with urea applied in March 2013. A collar made from 21-cm diameter x 11-cm long PVC piping was installed in each of the 16 plots between two large trees on the forest floor, penetrating the organic layer to the mineral soil at the 5-8 cm depth. A clear Plexiglas lid, equipped with a 10-cm long vent tube and 9-V fan, was placed on each collar when making measurements, with 20-mL samples of chamber headspace air collected at 0, 3, 6, 9 and 12 min using a medical syringe with 21-gauge needle inserted through a rubber septum in the chamber lid. Samples were injected into and transported in previously

  5. Response of old-growth conifers to reduction in stand density in western Oregon forests

    Science.gov (United States)

    Latham, P.; Tappeiner, J. C.

    2002-01-01

    The positive growth response of healthy young trees to density reduction is well known. In contrast, large old trees are usually thought to be intrinsically limited in their ability to respond to increased growing space; therefore, density reduction is seldom used in stands of old-growth trees. We tested the null hypothesis that old-growth trees are incapable of responding with increased growth following density reduction. The diameter growth response of 271 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), ponderosa pine (Pinus ponderosa Dougl. ex Laws) and sugar pine (Pinus lambertiana Dougl.) trees ranging in age from 158 to 650 years was examined 20 to 50 years after density reduction. Density reduction involved either light thinning with removal of less vigorous trees, or shelterwood treatments in which overstory trees were not removed. Ratios of basal area growth after treatment to basal area growth before treatment, and several other measures of growth, all indicated that the old trees sometimes benefited and were not harmed by density reduction. Growth increased by 10% or more for 68% of the trees in treated stands, and nearly 30% of trees increased growth by over 50%. This growth response persisted for at least 20 years. During this 20-year period, only three trees in treated stands (1.5%) exhibited a rapid decrease in growth, whereas growth decreased in 64% of trees in untreated stands. The length of time before a growth response to density reduction occurred varied from 5 to 25 years, with the greatest growth response often occurring 20 to 25 years after treatment. These results have important implications both for the basic biology of aging in woody plants as well as for silvicultural practices in forests with old-growth trees.

  6. Douglas-fir growth and yield: research 1909-1960.

    Science.gov (United States)

    R.O. Curtis; D.D. Marshall

    2004-01-01

    Systematic research on growth and yield of Douglas-fir began in 1909. This line of early research evolved over time and culminated in publication of USDA Bulletin 201, The Yield of Douglas-fir in the Pacific Northwest. B201 had an enormous influence on development of Douglas-fir forestry and was arguably the most influential single research publication ever produced in...

  7. Effects of manganese and manganese-nitrogen applications on growth and nutrition of Douglas-fir seedlings.

    Science.gov (United States)

    M. A. Radwan; John S. Shumway; Dean S. DeBell

    1979-01-01

    Effects of manganese (Mn) on Douglas-fir grown in soil, with and without urea, and in nutrient solution were investigated. In addition, Mn sorption by forest soils was evaluated. Results show that Douglas-fir does not respond to added Mn and is quite tolerant to high Mn levels. Moreover, Mn sorption by soils is high. It is doubtful that Mn toxicity is of practical...

  8. Inheritance of graft compatibility in Douglas fir.

    Science.gov (United States)

    D.L. Copes

    1973-01-01

    Graft compatibility of genetically related and unrelated rootstock-scion combinations was compared. Scion clones were 75% compatible when grafted on half-related rootstocks but only 56% compatible when grafted on unrelated rootstocks. Most variance associated with graft incompatibility in Douglas-fir appears to be caused by multiple genes.

  9. Vertical stratification of soil water storage and release dynamics in Pacific Northwest coniferous forests.

    Science.gov (United States)

    J.M. Warren; F.C. Meinzer; J.R. Brooks; J.C. Domec

    2005-01-01

    We characterized vertical variation in the seasonal release of stored soil moisture in old-growth ponderosa pine (OG-PP, xeric), and young and old-growth Douglas-fir (Y-DF, OG-DF, mesic) forests to evaluate changes in water availability for root uptake. Soil water potential (ψ) and volumetric water content (θ...

  10. Regeneration in mixed conifer and Douglas-fir shelterwood cuttings in the Cascade Range of Washington.

    Science.gov (United States)

    K.W. Seidel

    1983-01-01

    A survey of shelterwood cuttings in mixed conifer and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests in the Cascade Range in Washington showed that, on the average, shelterwood units were adequately-stocked with a mixture of advance, natural postharvest, and planted reproduction of a number of species. Shelterwood cuttings in the...

  11. Lack of caching of direct-seeded Douglas fir seeds by deer mice

    International Nuclear Information System (INIS)

    Sullivan, T.P.

    1978-01-01

    Seed caching by deer mice was investigated by radiotagging seeds in forest and clear-cut areas in coastal British Columbia. Deer mice tend to cache very few Douglas fir seeds in the fall when the seed is uniformly distributed and is at densities comparable with those used in direct-seeding programs. (author)

  12. Nitrogen turnover in fresh Douglas fir litter directly after additions of moisture and inorganic nitrogen

    NARCIS (Netherlands)

    Raat, K.J.; Tietema, A.; Verstraten, J.M.

    2010-01-01

    The effects of wetting and drying and inorganic nitrogen (N) addition on carbon (C) and N turnover in fresh Douglas fir litter (Speuld forest, the Netherlands) were investigated. Litter was incubated for 9 days in the laboratory, receiving different moisture and N addition treatments. Following the

  13. Dynamic phenotypic plasticity in photosynthesis and biomass patterns in Douglas-fir seedlings

    Science.gov (United States)

    A. C. Koehn; G. I. McDonald; D. L. Turner; D. L. Adams

    2010-01-01

    As climate changes, understanding the mechanisms long-lived conifers use to adapt becomes more important. Light gradients within a forest stand vary constantly with the changes in climate, and the minimum light required for survival plays a major role in plant community dynamics. This study focuses on the dynamic plasticity of Douglas-fir (Pseudotsuga menziesii var....

  14. Fungal endophytes in woody roots of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa)

    Science.gov (United States)

    J. A. Hoff; Ned B. Klopfenstein; Geral I. McDonald; Jonalea R. Tonn; Mee-Sook Kim; Paul J. Zambino; Paul F. Hessburg; J. D. Rodgers; T. L. Peever; L. M. Carris

    2004-01-01

    The fungal community inhabiting large woody roots of healthy conifers has not been well documented. To provide more information about such communities, a survey was conducted using increment cores from the woody roots of symptomless Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) growing in dry forests...

  15. Structural lumber from dense stands of small-diameter Douglas-fir trees.

    Science.gov (United States)

    David W. Green; Eini C. Lowell; Roland Hernandez

    2005-01-01

    Small-diameter trees growing in overstocked dense stands are often targeted for thinning to reduce fire hazard and improve forest health and ecosystem diversity. In the Pacific Northwest and Intermountain regions, Douglas-fir can be a predominant species in such stands. In this study, mechanical properties and grade yield of structural products were estimated for 2 by...

  16. Management, morphological, and environmental factors influencing Douglas-fir bark furrows in the Oregon Coast Range

    Science.gov (United States)

    Sheridan, Christopher D.; Puettmann, Klaus J.; Huso, Manuela M.P.; Hagar, Joan C.; Falk, Kristen R.

    2013-01-01

    Many land managers in the Pacific Northwest have the goal of increasing late-successional forest structures. Despite the documented importance of Douglas-fir tree bark structure in forested ecosystems, little is known about factors influencing bark development and how foresters can manage development. This study investigated the relative importance of tree size, growth, environmental factors, and thinning on Douglas-fir bark furrow characteristics in the Oregon Coast Range. Bark furrow depth, area, and bark roughness were measured for Douglas-fir trees in young heavily thinned and unthinned sites and compared to older reference sites. We tested models for relationships between bark furrow response and thinning, tree diameter, diameter growth, and environmental factors. Separately, we compared bark responses measured on trees used by bark-foraging birds with trees with no observed usage. Tree diameter and diameter growth were the most important variables in predicting bark characteristics in young trees. Measured environmental variables were not strongly related to bark characteristics. Bark furrow characteristics in old trees were influenced by tree diameter and surrounding tree densities. Young trees used by bark foragers did not have different bark characteristics than unused trees. Efforts to enhance Douglas-fir bark characteristics should emphasize retention of larger diameter trees' growth enhancement.

  17. Old-growth forests as global carbon sinks

    NARCIS (Netherlands)

    Luyssaert, S; Schulze, E.D.; Börner, A.

    2008-01-01

    Old- growth forests remove carbon dioxide from the atmosphere(1,2) at rates that vary with climate and nitrogen deposition(3). The sequestered carbon dioxide is stored in live woody tissues and slowly decomposing organic matter in litter and soil(4). Old- growth forests therefore serve as a global

  18. An Old-Growth Definition for Southern Mixed Hardwood Forests

    Science.gov (United States)

    William B. Batista; William J. Platt

    1997-01-01

    This report provides an old-growth definition for the southern mixed hardwood forests based on five exemplary stands that show no evidence of having undergone any natural catastrophe or clearcutting for at least 200 years. This forest type occurs in the U.S. southeastern Coastal Plain from the Carolinas to eastern Texas. The exemplary old-growth stands were restricted...

  19. Douglas-fir tussock moth: an annotated bibliography.

    Science.gov (United States)

    Robert W. Campbell; Lorna C. Youngs

    1978-01-01

    This annotated bibliography includes references to 338 papers. Each deals in some way with either the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), or a related species. Specifically, 210 publications and 82 unpublished documents make some reference, at least, to the Douglas-fir tussock moth; 55 are concerned with other species in...

  20. Size of Douglas-fir trees in relation to distance from a mixed red alder - Douglas-fir stand

    Science.gov (United States)

    R.E. Miller; D.L. Reukema; T.A. Max

    1993-01-01

    Variation in diameter, height, and stem volume of 57-year-old Douglas-fir(Pseudotsuga menziesii var. menziesii (Mirb.) Franco) was related to distance of these trees from a 27 m wide strip in the same Douglas-fir plantation that had been interplanted with red alder (Alnus rubra Bong.). Within the...

  1. Species effect on the water use efficiency of a mixed forest of beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and silver fir (Abies alba Mill.) in Belgium Ardennes.

    Science.gov (United States)

    Soubie, Rémy; Heinesch, Bernard; Aubinet, Marc; Vincke, Caroline

    2010-05-01

    Induced by climate change, intensity and frequency of droughts should be more important for the next century. How does water availability affect the physiology of woody plants at the species and stand scale? Carbon and water vapour fluxes measurements of a mixed forest (deciduous and coniferous) were performed for over ten years by the eddy covariance method in Belgian Ardennes (Aubinet et al, 2001) as a part of the CarboEurope project. Whereas carbon fluxes have been analyzed in detailed and good estimations of the Net Ecosystem Exchange (NEE) and Gross Primary Production (GPP) were obtained, a thorough analysis of water vapour fluxes remains to be done. Improving analysis of water vapour fluxes and monitoring species transpiration will contribute to the estimation of the water use efficiency, WUE, at both the species and stand scale. The WUE well characterizes the vegetation productivity and ecosystem response to environmental factors. It also allows evaluating the sensitivity of temperate woody species to drought. The species concerned are beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and silver fir (Abies alba Mill.). Since summer 2009 we monitor and analyze each species water use by measuring sap flow with the thermal dissipation method (Granier, 1987). Results at the species level will then be upscaled and compared to stand water vapour fluxes measurements obtained by the eddy covariance methodology. Transpiration of each species will be analyzed in relation with their own phenological and ecophysiological attributes, ecosystem soil and atmospheric conditions, to clarify among others their behaviour in case of water deficit. Data are actually analysed, the presented results will concern the 2009, and a part of 2010 growing season.

  2. Inheritance of germinative energy and germinative capacity in Douglas-fir

    Science.gov (United States)

    Thomas E. Greathouse

    1966-01-01

    In the West foresters have had considerable difficulty in reforesting south-facing slopes. We considered this problem when we selected plus-trees for the first Douglas-fir seed orchard in Region 6. We were, however, faced with the need to answer such questions as these: (1) Should we try to produce seed inherently suited for south slopes? (2) If so, should we strive to...

  3. Growth after precommercial thinning in two stands of Douglas-fir.

    Science.gov (United States)

    Robert W. Steele

    1955-01-01

    Twenty years ago, portions of two young Douglas-fir stands on the Wind River Experimental Forest in Skamania County, Washington, were thinned by removing some of the trees in the suppressed and intermediate crown classes. At time of thinning, one stand, (A), was 23 years old and the second, (B), was 30 years old. In both cases site quality is IV. The trees taken out...

  4. THE USE OF INTER SIMPLE SEQUENCE REPEATS (ISSR) IN DISTINGUISHING NEIGHBORING DOUGLAS-FIR TREES AS A MEANS TO IDENTIFYING TREE ROOTS WITH ABOVE-GROUND BIOMASS

    Science.gov (United States)

    We are attempting to identify specific root fragments from soil cores with individual trees. We successfully used Inter Simple Sequence Repeats (ISSR) to distinguish neighboring old-growth Douglas-fir trees from one another, while maintaining identity among each tree's parts. W...

  5. Growth response of Douglas-fir seedlings to nitrogen fertilization: importance of Rubisco activation state and respiration rates.

    Science.gov (United States)

    Daniel K. Manter; Kathleen L. Kavanagh; Cathy L. Rose

    2005-01-01

    High foliar nitrogen concentration ([N]) is associated with high rates of photosynthesis and thus high tree productivity; however, at excessive [N], tree productivity is reduced. Reports of excessive [N] in the Douglas-fir forests of the Oregon Coast Range prompted this investigation of growth and needle physiological responses to increasing foliar N concentrations in...

  6. Height-growth response to climatic changes differs among populations of Douglas-fir: A novel analysis of historic data

    Science.gov (United States)

    Laura P. Leites; Andrew P. Robinson; Gerald E. Rehfeldt; John D. Marshall; Nicholas L. Crookston

    2012-01-01

    Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach,...

  7. EFFECTS OF ELEVATED CO2 AND TEMPERATURE ON SOIL CARBON DENSITY FRACTIONS IN A DOUGLAS FIR MESOCOSM STUDY

    Science.gov (United States)

    We conducted a 4-year full-factorial study of the effects of elevated atmospheric CO2 and temperature on Douglas fir seedlings growing in reconstructed native forest soils in mesocosms. The elevated CO2 treatment was ambient CO2 plus 200 ppm CO2. The elevated temperature treatm...

  8. Fine-scale variability in growth-climate relationships of Douglas-fir, North Cascade Range, Washington.

    Science.gov (United States)

    Michael J. Case; David L. Peterson

    2005-01-01

    Information about the sensitivity to climate of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is valuable because it will allow forest managers to maximize growth, better understand how carbon sequestration may change over time, and better model and predict future ecosystem responses to climatic change. We examined the effects of climatic...

  9. Old-growth forests can accumulate carbon in soils

    Science.gov (United States)

    Zhou, G.; Liu, S.; Li, Z.; Zhang, Dongxiao; Tang, X.; Zhou, C.; Yan, J.; Mo, J.

    2006-01-01

    Old-growth forests have traditionally been considered negligible as carbon sinks because carbon uptake has been thought to be balanced by respiration. We show that the top 20-centimeter soil layer in preserved old-growth forests in southern China accumulated atmospheric carbon at an unexpectedly high average rate of 0.61 megagrams of carbon hectare-1 year-1 from 1979 to 2003. This study suggests that the carbon cycle processes in the belowground system of these forests are changing in response to the changing environment. The result directly challenges the prevailing belief in ecosystem ecology regarding carbon budget in old-growth forests and supports the establishment of a new, nonequilibrium conceptual framework to study soil carbon dynamics.

  10. Carbon Transfers and Emissions Following Harvest and Pile Burning in Coastal Douglas-fir Forests Determined from Analysis of High-Resolution UAV Imagery and Point Clouds and from Field Surveys.

    Science.gov (United States)

    Trofymow, J. A.; Gougeon, F.; Kelley, J. W.

    2017-12-01

    Forest carbon (C) models require knowledge on C transfers due to intense disturbances such as fire, harvest, and slash burning. In such events, live trees die and C transferred to detritus or exported as round wood. With burning, live and detrital C is lost as emissions. Burning can be incomplete, leaving wood, charred and scattered or in unburnt rings and piles. For harvests, all round wood volume is routinely measured, while dispersed and piled residue volumes are typically assessed in field surveys, scaled to a block. Recently, geospatial methods have been used to determine, for an entire block, piled residues using LiDAR or image point clouds (PC) and dispersed residues by analysis of high-resolution imagery. Second-growth Douglas-fir forests on eastern Vancouver Island were examined, 4 blocks at Oyster River (OR) and 2 at Northwest Bay (NB). OR blocks were cut winter 2011, piled spring 2011, field survey, aerial RGB imagery and LiDAR PC acquired fall 2011, piles burned, burn residues surveyed, and post-burn aerial RGB imagery acquired 2012. NB blocks were cut fall 2014, piled spring 2015, field survey, UAV RGB imagery and image PC acquired summer 2015, piles burned and burn residues surveyed spring 2016, and post-burn UAV RGB imagery and PC acquired fall 2016. Volume to biomass conversion used survey species proportions and wood density. At OR, round wood was 261.7 SE 13.1, firewood 1.7 SE 0.3, and dispersed residue by survey, 13.8 SE 3.6 tonnes dry mass (t dm) ha-1. Piled residues were 8.2 SE 0.9 from pile surveys vs. 25.0 SE 5.9 t dm ha-1 from LiDAR PC bulk pile volumes and packing ratios. Post-burn, piles lost 5.8 SE 0.5 from survey of burn residues vs. 18.2 SE 4.7 t dm ha-1 from pile volume changes using 2011 LiDAR PC and 2012 imagery. The percentage of initial merchantable biomass exported as round & fire wood, remaining as dispersed & piled residue, and lost to burning was, respectively, 92.5%, 5.5% and 2% using only field methods vs. 87%, 7% and 6% from

  11. Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate

    Science.gov (United States)

    Wang, Zheng Q.; Newton, M.; Tappeiner, J. C.

    1995-01-01

    A large area of Pacific Coast forests is characterized by shallow soil, with negligible rainfall in the growing season. This study explores water-seeking strategy on such a site. We studied availability of bedrock water and its effects on growth and ecophysiology of 11-yr-old planted Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and sprouting Pacific madrone (Arbutus menziesii Pursh). The study was carried out at three regulated densities of madrone sprouts on shallow ( 0.05) among three densities of madrone. However, cover in plots with the highest density of madrone (1322 sprout clumps/ha) depleted 50 mm of water from the 1.5 m layer by June, whereas vegetation on lower density treatments withdrew 15-28 mm by June, with later withdrawal distributed more uniformly through the growing season. Madrone density significantly affected basal diameter (P a?? 0.0001) and height growth (P a?? 0.002) of Douglas-fir. Madrone was consistently taller than Douglas-fir in all plots. The height of 11-yr-old madrone sprout clumps (424-465 cm) did not differ significantly among densities. Madrone leaf area index and biomass were higher at the high density of madrone than at medium density (P a?? 0.045, LAI; P a?? 0.001, biomass). Physiological advantages and rooting habits of madrone give it a competitive advantage over Douglas-fir in this area that it might not have if bedrock did not provide the principal water reservoir for summer growth.

  12. Effects of stand composition and thinning in mixed-species forests : a modeling approach applied to Douglas-fir and beech

    NARCIS (Netherlands)

    Bartelink, H.H.

    2000-01-01

    Models estimating growth and yield of forest stands provide important tools for forest management. Pure stands have been modeled extensively and successfully for decades; however, relatively few models for mixed-species stands have been developed. A spatially explicit, mechanistic model (COMMIX) is

  13. Responses of cavity-nesting birds to stand-replacement fire and salvage logging in ponderosa pine/Douglas-fir forests of southwestern Idaho

    Science.gov (United States)

    Victoria A. Saab; Jonathan G. Dudley

    1998-01-01

    From 1994 to 1996, researchers monitored 695 nests of nine cavity-nesting bird species and measured vegetation at nest sites and at 90 randomly located sites in burned ponderosa pine forests of southwestern Idaho. Site treatments included two types of salvage logging, and unlogged controls. All bird species selected nest sites with higher tree densities, larger...

  14. Nitrogen Fertilization Effects on Net Ecosystem and Net Primary Productivities as Determined from Flux Tower, Biometric, and Model Estimates for a Coastal Douglas-fir Forest in British Columbia

    Science.gov (United States)

    Trofymow, J. A.; Metsaranta, J. M.; Black, T. A.; Jassal, R. S.; Filipescu, C.

    2013-12-01

    In coastal BC, 6,000-10,000 ha of public and significant areas of private forest land are annually fertilized with nitrogen, with or without thinning, to increase merchantable wood and reduce rotation age. Fertilization has also been viewed as a way to increase carbon (C) sequestration in forests and obtain C offsets. Such offset projects must demonstrate additionality with reference to a baseline and include monitoring to verify net C gains over the project period. Models in combination with field-plot measurements are currently the accepted methods for most C offset protocols. On eastern Vancouver Island, measurements of net ecosystem production (NEP), ecosystem respiration (Re) and gross primary productivity (GPP) using the eddy-covariance (EC) technique as well as component C fluxes and stocks have been made since 1998 in an intermediate-aged Douglas-fir dominated forest planted in 1949. In January 2007 an area around the EC flux tower was aerially fertilized with 200 kg urea-N ha-1. Ground plots in the fertilized area and an adjacent unfertilized control area were also monitored for soil (Rs) and heterotrophic (Rh) respiration, litterfall, and tree growth. To determine fertilization effects on whole tree growth, sample trees were felled in both areas for the 4-year (2003-06) pre- and the 4-year (2007-10) post-fertilization periods and were compared with EC NEP estimates and tree-ring based NEP estimates from Carbon Budget Model - Canadian Forest Sector (CBM-CFS3) for the same periods. Empirical equations using climate and C fluxes from 1998-2006 were derived to estimate what the EC fluxes would have been in 2007-10 for the fertilized area had it been unfertilized. Mean EC NEP for 2007-10 was 561 g C m2 y-1 , a 64% increase above pre-fertilization NEP (341 g C m2 y-1) or 28% increase above estimated unfertilized NEP (438 g C m2 y-1). Most of the increase was attributed to increased tree C uptake (i.e., GPP), with little change in Re. In 2007 fertilization

  15. Dynamics of spectral bio-indicators and their correlations with light use efficiency using directional observations at a Douglas-fir forest

    Science.gov (United States)

    Cheng, Yen-Ben; Middleton, Elizabeth M.; Hilker, Thomas; Coops, Nicholas C.; Black, T. Andrew; Krishnan, Praveena

    2009-09-01

    The carbon science community must rely on satellite remote sensing to obtain global estimates of photosynthetic activity, typically expressed as net primary production (NPP), gross primary production (GPP) or light use efficiency (LUE). The photochemical reflectance index (PRI), calculated as a normalized difference reflectance index using a physiologically active green band (~531 nm) and another physiologically insensitive green reference band (~570 nm), denoted as PRI(570), has been confirmed in many studies as being strongly related to LUE. Here, we examined the potential of utilizing PRI(570) observations under different illumination conditions for canopy LUE estimation of a forest. In order to evaluate this, directional hyperspectral reflectance measurements were collected continuously throughout the daytime periods using an automated spectroradiometer in conjunction with tower-based eddy covariance fluxes and environmental measurements at a coastal conifer forest in British Columbia, Canada throughout the 2006 growing season. A parameter calculated as the PRI(570) difference (dPRI(570)) between shaded versus sunlit canopy foliage sectors showed a strong correlation to tower-based LUE. The seasonal pattern for this correlation produced a dramatic change from high negative (r ~ -0.80) values in the springtime and early fall to high positive values (r ~ 0.80) during the summer months, which could represent the seasonality of physiological characteristics and environmental factors. Although the PRI(570) successfully tracked canopy LUE, one or both of its green bands (~531 and 570 nm) used to calculate the PRI are unavailable on most existing and planned near-term satellites. Therefore, we examined the potential to use 24 other spectral indexes for LUE monitoring that might be correlated to PRI, and thereby a substitute for it. We also continued our previous investigations into the influence of illumination conditions on the observed PRI(570) and other indexes

  16. Dynamics of spectral bio-indicators and their correlations with light use efficiency using directional observations at a Douglas-fir forest

    International Nuclear Information System (INIS)

    Cheng, Yen-Ben; Middleton, Elizabeth M; Hilker, Thomas; Coops, Nicholas C; Black, T Andrew; Krishnan, Praveena

    2009-01-01

    The carbon science community must rely on satellite remote sensing to obtain global estimates of photosynthetic activity, typically expressed as net primary production (NPP), gross primary production (GPP) or light use efficiency (LUE). The photochemical reflectance index (PRI), calculated as a normalized difference reflectance index using a physiologically active green band (∼531 nm) and another physiologically insensitive green reference band (∼570 nm), denoted as PRI(570), has been confirmed in many studies as being strongly related to LUE. Here, we examined the potential of utilizing PRI(570) observations under different illumination conditions for canopy LUE estimation of a forest. In order to evaluate this, directional hyperspectral reflectance measurements were collected continuously throughout the daytime periods using an automated spectroradiometer in conjunction with tower-based eddy covariance fluxes and environmental measurements at a coastal conifer forest in British Columbia, Canada throughout the 2006 growing season. A parameter calculated as the PRI(570) difference (dPRI(570)) between shaded versus sunlit canopy foliage sectors showed a strong correlation to tower-based LUE. The seasonal pattern for this correlation produced a dramatic change from high negative (r ∼ −0.80) values in the springtime and early fall to high positive values (r ∼ 0.80) during the summer months, which could represent the seasonality of physiological characteristics and environmental factors. Although the PRI(570) successfully tracked canopy LUE, one or both of its green bands (∼531 and 570 nm) used to calculate the PRI are unavailable on most existing and planned near-term satellites. Therefore, we examined the potential to use 24 other spectral indexes for LUE monitoring that might be correlated to PRI, and thereby a substitute for it. We also continued our previous investigations into the influence of illumination conditions on the observed PRI(570) and other

  17. Factors affecting diurnal stem contraction in young Douglas-fir

    Science.gov (United States)

    Warren D. Devine; Constance Harrington

    2011-01-01

    Diurnal fluctuation in a tree's stem diameter is a function of daily growth and of the tree's water balance, as water is temporarily stored in the relatively elastic outer cambial and phloem tissues. On a very productive site in southwestern Washington, U.S.A we used recording dendrometers to monitor stem diameter fluctuations of Douglas-fir at plantation...

  18. Predicting Douglas-fir's response to a warming climate

    Science.gov (United States)

    Andrea Watts; Sheel Bansal; Connie Harrington; Brad. St. Clair

    2015-01-01

    Douglas-fir is an iconic tree in the Pacific Northwest. Although individual trees may appear to be identical, genetic differences within each tree have resulted from adaptation to the local environment. These genetic differences over time have resulted in differences among populations that are important to the species' survival and growth in changing climates....

  19. Some economic considerations in thinning Douglas-fir.

    Science.gov (United States)

    Norman P. Worthington

    1957-01-01

    Many thousands of acres of young Douglas-fir stands in western Washington are ready for commercial thinning. This is true even after liberal allowance is made for premerchantable and under stocked stands, unfavorable topography, and lack of markets. However, with but few exceptions, regular systematic thinning is not being practiced even in favorably located, operable...

  20. Developmental decline in height growth in Douglas-fir.

    Science.gov (United States)

    Barbara J. Bond; Nicole M. Czarnomski; Clifton Cooper; Michael E. Day; Michael S. Greenwood

    2007-01-01

    The characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." But is the reduction in height growth in aging trees a function of age or of size? We grafted shoot tips across different ages and sizes of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees to determine whether...

  1. Effects of bear damage on Douglas-fir lumber recovery

    Science.gov (United States)

    Eini C. Lowell; Dennis Dykstra; George McFadden

    2009-01-01

    Bear activily resulting in injury to Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees has been documented as early as the mid-1850s in the Pacific Northwest. The study reported in this article was designed to help managers decide whether the common practice of removing the damaged but potentially valuable butt section of the bottom log and...

  2. Development over 25 years of Douglas-fir, western hemlock, and western redcedar planted at various spacings on a very good site in British Columbia.

    Science.gov (United States)

    Donald L. Reukema; J. Harry G. Smith

    1987-01-01

    Results of five spacing trials on the University of British Columbia Research Forest, covering a range of plantation spacings from 1 to 5 meters, showed that choice of initial spacing is among the most important factors influencing bole and crown development and stand growth and yield. The trials include Douglas-fir (Pseudotsuga menziesi), western...

  3. Early survival and height growth of Douglas-fir and lodgepole pine seedlings and variations in site factors following treatment of logging residues.

    Science.gov (United States)

    W. Lopushlnsky; D. Zabowskl; T.D. Anderson

    1992-01-01

    Logging residues were broadcast burned, piled and burned, removed, or left in place after clearcutting in a high-elevation subalpine fir (Abies lasiocarpa (Hook.) Nutt.) lodgepole pine (Pinus contorta Dougl. ex Loud.) forest in north-central Washington. Survival, height growth and foliar nutrient content of planted Douglas-fir...

  4. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    Science.gov (United States)

    C. Phillips; L.A. Kluber; J.P. Martin; B.A. Caldwell; B.J. Bond

    2012-01-01

    Distinct aggregations of fungal hyphae and rhizomorphs, or “mats”, formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was...

  5. Foliar nitrogen metabolism of adult Douglas-fir trees is affected by soil water availability and varies little among provenances.

    Science.gov (United States)

    Du, Baoguo; Kreuzwieser, Jürgen; Dannenmann, Michael; Junker, Laura Verena; Kleiber, Anita; Hess, Moritz; Jansen, Kirstin; Eiblmeier, Monika; Gessler, Arthur; Kohnle, Ulrich; Ensminger, Ingo; Rennenberg, Heinz; Wildhagen, Henning

    2018-01-01

    The coniferous forest tree Douglas-fir (Pseudotsuga menziesii) is native to the pacific North America, and is increasingly planted in temperate regions worldwide. Nitrogen (N) metabolism is of great importance for growth, resistance and resilience of trees. In the present study, foliar N metabolism of adult trees of three coastal and one interior provenance of Douglas-fir grown at two common gardens in southwestern Germany (Wiesloch, W; Schluchsee, S) were characterized in two subsequent years. Both the native North American habitats of the seed sources and the common garden sites in Germany differ in climate conditions. Total and mineral soil N as well as soil water content were higher in S compared to W. We hypothesized that i) provenances differ constitutively in N pool sizes and composition, ii) N pools are affected by environmental conditions, and iii) that effects of environmental factors on N pools differ among interior and coastal provenances. Soil water content strongly affected the concentrations of total N, soluble protein, total amino acids (TAA), arginine and glutamate. Foliar concentrations of total N, soluble protein, structural N and TAA of trees grown at W were much higher than in trees at S. Provenance effects were small but significant for total N and soluble protein content (interior provenance showed lowest concentrations), as well as arginine, asparagine and glutamate. Our data suggest that needle N status of adult Douglas-fir is independent from soil N availability and that low soil water availability induces a re-allocation of N from structural N to metabolic N pools. Small provenance effects on N pools suggest that local adaptation of Douglas-fir is not dominated by N conditions at the native habitats.

  6. An Old-Growth Definition for Dry and Dry-Mesic Oak-Pine Forests.

    Science.gov (United States)

    David L. White; F. Thomas. Lloyd

    1998-01-01

    Dry and dry-mesic oak-pine forests are widely distributed from New Jersey to Texas, but representative old-growth stands are rare. Historical accounts of composition, along with information from existing old-growth stands, were used to characterize this type. Shortleaf pine and white oak were the most widely distributed trees across all old-growth stands. Shortleaf was...

  7. Eco-physiological characteristics and variation in water source use between montane Douglas-Fir and lodgepole pine trees in southwestern Alberta

    Science.gov (United States)

    Andrews, S.; Flanagan, L. B.

    2009-12-01

    Winter weather on the Canadian prairies is now warmer and drier than 50 years ago and this has implications for soil water re-charge in montane ecosystems with consequences for tree and ecosystem function. We used measurements of the hydrogen isotope ratio of tree stem water to analyze the use of different water sources (winter snow melt, ground water, summer precipitation) in two montane forest sites, one dominated by Douglas-Fir and the other dominated by lodgepole pine trees. On average during the growing season (May-October) stem water in both Douglas-Fir and lodgepole pine trees was composed of 60% summer precipitation. However, during late summer Douglas-Fir trees showed an increased use of ground water as summer precipitation was minimal and ground water was accessible at the bottom of a relatively large soil reservoir. The low summer precipitation and reduced soil water availability in the shallow soils at the lodgepole pine site resulted in severely reduced photosynthetic capacity in late summer. Increased precipitation during the autumn resulted in recovery of photosynthetic gas exchange in lodgepole pine before winter dormancy was induced by low temperatures. Stomatal limitation of photosynthesis, as estimated from measurements of the carbon isotope composition of leaf tissue, was higher in Douglas-Fir than lodgepole pine. This was also associated with lower midday water potential values in Douglas-Fir and sapwood cross-sectional area that was only 70% of that measured in lodgepole pine. The vulnerability of xylem to loss of conductivity with declines in water potential was very similar between the two species. However, midday water potential in Douglas-Fir approached values where cavitation and loss of conductivity were apparent, while in lodgepole pine midday water potential was always much higher than the point at which loss of hydraulic conductivity occurred. These data suggest that, despite the presence of Douglas-Fir on deeper and higher quality

  8. Projected future suitable habitat and productivity of Douglas-fir in western North America

    Science.gov (United States)

    Aaron R. Weiskittel; Nicholas L. Crookston; Gerald E. Rehfeldt

    2012-01-01

    Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is one of the most common and commercially important species in western North America. The species can occupy a range of habitats, is long-lived (up to 500 years), and highly productive. However, the future of Douglas-fir in western North America is highly uncertain due to the expected changes in climate conditions....

  9. Belowground competition from overstory trees influences Douglas-fir sapling morphology in thinned stands

    Science.gov (United States)

    Warren D. Devine; Timothy B. Harrington

    2009-01-01

    We evaluated effects of belowground competition on morphology of naturally established coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) saplings in 60- to 80-year-old thinned Douglas-fir stands in southwestern Washington. We separately quantified belowground competition from overstory and understory sources...

  10. Spatially random mortality in old-growth red pine forests of northern Minnesota

    Science.gov (United States)

    Tuomas ​Aakala; Shawn Fraver; Brian J. Palik; Anthony W. D' Amato

    2012-01-01

    Characterizing the spatial distribution of tree mortality is critical to understanding forest dynamics, but empirical studies on these patterns under old-growth conditions are rare. This rarity is due in part to low mortality rates in old-growth forests, the study of which necessitates long observation periods, and the confounding influence of tree in-growth during...

  11. Regional patterns of increasing Swiss needle cast impacts on Douglas-fir growth with warming temperatures.

    Science.gov (United States)

    Lee, E Henry; Beedlow, Peter A; Waschmann, Ronald S; Tingey, David T; Cline, Steven; Bollman, Michael; Wickham, Charlotte; Carlile, Cailie

    2017-12-01

    The fungal pathogen, Phaeocryptopus gaeumannii , causing Swiss needle cast (SNC) occurs wherever Douglas-fir is found but disease damage is believed to be limited in the U.S. Pacific Northwest (PNW) to the Coast Range of Oregon and Washington (Hansen et al., Plant Disease , 2000, 84 , 773; Rosso & Hansen, Phytopathology , 2003, 93 , 790; Shaw, et al., Journal of Forestry , 2011, 109 , 109). However, knowledge remains limited on the history and spatial distribution of SNC impacts in the PNW. We reconstructed the history of SNC impacts on mature Douglas-fir trees based on tree-ring width chronologies from western Oregon. Our findings show that SNC impacts on growth occur wherever Douglas-fir is found and is not limited to the coastal fog zone. The spatiotemporal patterns of growth impact from SNC disease were synchronous across the region, displayed periodicities of 12-40 years, and strongly correlated with winter and summer temperatures and summer precipitation. The primary climatic factor limiting pathogen dynamics varied spatially by location, topography, and elevation. SNC impacts were least severe in the first half of the 20th century when climatic conditions during the warm phase of the Pacific Decadal Oscillation (1924-1945) were less conducive to pathogen development. At low- to mid-elevations, SNC impacts were most severe in 1984-1986 following several decades of warmer winters and cooler, wetter summers including a high summer precipitation anomaly in 1983. At high elevations on the west slope of the Cascade Range, SNC impacts peaked several years later and were the greatest in the 1990s, a period of warmer winter temperatures. Climate change is predicted to result in warmer winters and will likely continue to increase SNC severity at higher elevations, north along the coast from northern Oregon to British Columbia, and inland where low winter temperatures currently limit growth of the pathogen. Our findings indicate that SNC may become a significant

  12. Climate indices strongly influence old-growth forest carbon exchange

    Science.gov (United States)

    Sonia Wharton; Matthias Falk

    2016-01-01

    We present a decade and a half (1998–2013) of carbon dioxide fluxes from an old-growth stand in the American Pacific Northwest to identify ecosystem-level responses to Pacific teleconnection patterns, including the El Niño/Southern Oscillation (ENSO). This study provides the longest, continuous record of old-growth eddy flux data to date from one of the longest running...

  13. Spatial elements of mortality risk in old-growth forests

    Science.gov (United States)

    Das, Adrian; Battles, John; van Mantgem, Phillip J.; Stephenson, Nathan L.

    2008-01-01

    For many species of long-lived organisms, such as trees, survival appears to be the most critical vital rate affecting population persistence. However, methods commonly used to quantify tree death, such as relating tree mortality risk solely to diameter growth, almost certainly do not account for important spatial processes. Our goal in this study was to detect and, if present, to quantify the relevance of such processes. For this purpose, we examined purely spatial aspects of mortality for four species, Abies concolor, Abies magnifica, Calocedrus decurrens, and Pinus lambertiana, in an old-growth conifer forest in the Sierra Nevada of California, USA. The analysis was performed using data from nine fully mapped long-term monitoring plots.In three cases, the results unequivocally supported the inclusion of spatial information in models used to predict mortality. For Abies concolor, our results suggested that growth rate may not always adequately capture increased mortality risk due to competition. We also found evidence of a facilitative effect for this species, with mortality risk decreasing with proximity to conspecific neighbors. For Pinus lambertiana, mortality risk increased with density of conspecific neighbors, in keeping with a mechanism of increased pathogen or insect pressure (i.e., a Janzen-Connell type effect). Finally, we found that models estimating risk of being crushed were strongly improved by the inclusion of a simple index of spatial proximity.Not only did spatial indices improve models, those improvements were relevant for mortality prediction. For P. lambertiana, spatial factors were important for estimation of mortality risk regardless of growth rate. For A. concolor, although most of the population fell within spatial conditions in which mortality risk was well described by growth, trees that died occurred outside those conditions in a disproportionate fashion. Furthermore, as stands of A. concolor become increasingly dense, such spatial

  14. Two decades of stability and change in old-growth forest at Mount Rainier National Park.

    Science.gov (United States)

    Steven A. Acker; Jerry F. Franklin; Sarah E. Greene; Ted B. Thomas; Robert Van Pelt; Kenneth J. Bible

    2006-01-01

    We examined how composition and structure of old-growth and mature forests at Mount Rainier National Park changed between the mid-1970s and mid-1990s. We assessed whether the patterns of forest dynamics observed in lower elevation old-growth forests in the Pacific Northwest held true for the higher-elevation forests of the Park. We used measurements of tree recruitment...

  15. Structural properties of laminated Douglas fir/epoxy composite material

    Energy Technology Data Exchange (ETDEWEB)

    Spera, D.A. (National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center); Esgar, J.B. (Sverdrup Technology, Inc., Cleveland, OH (USA)); Gougeon, M.; Zuteck, M.D. (Gougeon Bros., Bay City, MI (USA))

    1990-05-01

    This publication contains a compilation of static and fatigue and strength data for laminated-wood material made from Douglas fir and epoxy. Results of tests conducted by several organizations are correlated to provide insight into the effects of variables such as moisture, size, lamina-to-lamina joint design, wood veneer grade, and the ratio of cyclic stress to steady stress during fatigue testing. These test data were originally obtained during development of wood rotor blades for large-scale wind turbines of the horizontal-axis (propeller) configuration. Most of the strength property data in this compilation are not found in the published literature. Test sections ranged from round cylinders 2.25 in. in diameter to rectangular slabs 6 in. by 24 in. in cross section and approximately 30 ft long. All specimens were made from Douglas fir veneers 0.10 in. thick, bonded together with the WEST epoxy system developed for fabrication and repair of wood boats. Loading was usually parallel to the grain. Size effects (reduction in strength with increase in test volume) are observed in some of the test data, and a simple mathematical model is presented that includes the probability of failure. General characteristics of the wood/epoxy laminate are discussed, including features that make it useful for a wide variety of applications. 9 refs.

  16. Spatial and Temporal Relationships of Old-Growth and Secondary Forests in Indiana, USA

    Science.gov (United States)

    Martin A. Spetich; George R. Parker; Eric J. Gustafson

    1997-01-01

    We examined the spatial pattern of forests in Indiana to: (1) determine the extent, connectivity and percent edge of all forests, (2) examine the change in connectivity among these forests if all riparian zones were replanted to forest or other native vegetation, (3) determine the location, spatial dispersion and percent edge of current old-growth forest remnants, (4)...

  17. Uptake of 15N labelled urea and ammonium nitrate by 4-year old Douglas-fir grown in sand-peat mix

    International Nuclear Information System (INIS)

    Pang, P.C.K.

    1982-01-01

    Four-year old Douglas-fir planted in a 1:1 ratio of sand and peat mixture were fertilized with 200 kg N/ha in the form of either ( 15 NH 2 ) 2 CO, 15 NH 4 NO 3 or NH 4 15 NO 3 and grown in a shadehouse over periods of one and two years. Under the experimental conditions, trees recovered a higher percentage of 15 N from the NO 3 - than the NH 4 + source. The soil retained a higher percentage of N from NH 4 + than the NO 3 - source. % Ndff suggested NO 3 - is the preferred N source for the Douglas-fir. A description is also given of some of the ongoing experiments related to N fertilization of forests underway at the Pacific Forest Research Centre. (author)

  18. Communicating old-growth forest management on the Allegheny National Forest

    Science.gov (United States)

    Brad Nelson; Chris Nowak; Dave deCalesta; Steve Wingate

    1997-01-01

    Successful communication of old-growth management, including the role of silviculture, is achieved by integrating as a working whole the topics addressed in this workshop. We have used research, technology transfer and adaptive management to achieve this integration on the Allegheny National Forest. Program success depends on scientists and practitioners working...

  19. Benchmark carbon stocks from old-growth forests in northern New England, USA

    Science.gov (United States)

    Coeli M. Hoover; William B. Leak; Brian G. Keel

    2012-01-01

    Forests world-wide are recognized as important components of the global carbon cycle. Carbon sequestration has become a recognized forest management objective, but the full carbon storage potential of forests is not well understood. The premise of this study is that old-growth forests can be expected to provide a reasonable estimate of the upper limits of carbon...

  20. Mixed-Species Effects on Soil C and N Stocks, C/N Ratio and pH Using a Transboundary Approach in Adjacent Common Garden Douglas-Fir and Beech Stands

    Directory of Open Access Journals (Sweden)

    Seid Muhie Dawud

    2017-03-01

    Full Text Available Mixed forest of Douglas-fir and beech has been suggested as one of the possible future forest types in Northwest Europe but the effects of this mixed forest on soil properties relative to monoculture stands are unknown. In a transboundary investigation of adjacent common garden Douglas-fir and beech stands, we determined the effects on topsoil properties. However, responses of C and N stocks, the C/N ratio and pH were site- and soil layer-specific and were mainly single-sided and without synergistic effects. Beech reduced the soil C and N stocks in Douglas-fir at the nutrient-poor site, caused an increase in the C/N ratio in the forest floor and mineral soil at both nutrient-poor and -rich sites, and reduced the acidifying effect of Douglas-fir at the nutrient-poor site. These results do not support the hypothesis that mixture effects would be consistent across sites and soil layers. The lack of synergistic effects may be attributed to the relatively similar litter quality or rooting depth that prevented any larger niche differentiation and complementarity. The results indicate that the transboundary approach within a mature common garden proved useful as a platform to test tree species interactions, and this approach could be explored in soil studies until dedicated mixed-species common gardens reach maturity.

  1. Capturing Old-Growth Values for Use in Forest Decision-Making

    Science.gov (United States)

    Owen, Rochelle J.; Duinker, Peter N.; Beckley, Thomas M.

    2009-02-01

    Old-growth forests have declined significantly across the world. Decisions related to old growth are often mired in challenges of value diversity, conflict, data gaps, and resource pressures. This article describes old-growth values of citizens and groups in Nova Scotia, Canada, for integration in sustainable forest management (SFM) decision-making. The study is based on data from 76 research subjects who participated in nine field trips to forest stands. Research subjects were drawn from Aboriginal groups, environmental organizations, forestry professionals, and rural and urban publics. Diaries, group discussions, and rating sheets were used to elicit information during the field trips. Findings show that different elicitation techniques can influence the articulation of intensity with which some values are held. In addition, certain values are more often associated with old-growth than with other forest-age classes. Some values associated with old-growth are considered more important than others, and some silvicultural treatments are perceived to compromise old-growth values more than others. Demographic characteristics, such as constituency group, gender, and age, are shown to influence value priorities. Ideas on how to incorporate old-growth values into SFM decision-making are highlighted.

  2. Early survival and growth of planted Douglas-fir with red alder in four mixed regimes.

    Science.gov (United States)

    Marshall D. Murray; Richard E. Miller

    1986-01-01

    To quantify between-species interactions, we measured and compared survival and growth of planted Douglas-fir and associated planted and volunteer red alder at a location on the west side of the Cascade Range in Washington. The planted alder were wildlings dug either from a nearby area or from a distant, coastal site and interplanted into a 3-year-old Douglas-fir...

  3. Identification of varieties and gene flow in Douglas fir exemplified in artificially established stands in Germany

    Directory of Open Access Journals (Sweden)

    Barbara Fussi

    2013-12-01

    Full Text Available Douglas-fir [Pseudotsuga menziesii (Mirb. Franco] is an economically valuable non-native tree species in Germany and is considered very promising in view of global climate change. Therefore, the genetic characterization of Douglas-fir populations and seed stands in Germany is essential. We studied coastal and interior Douglas-fir varieties, both present in Germany, by using eleven isoenzyme and four microsatellite loci. By analyzing eight reference populations of known origin we were able to identify the two varieties on the population level using Bayesian and distance based methods. Seven populations present in Bavaria were then successfully assigned to one of the two varieties. Within varieties we found stronger grouping within the interior variety than within the coastal one. Despite lower differences within coastal Douglas-fir we have first indications for the origin of two populations. For two Bavarian populations, natural regeneration was included and genetic data revealed no significant genetic difference between adults and offspring. The parentage analysis for one of the studied stands revealed that a large proportion of adults took part in the reproduction, but some trees were more successful than others in transferring their genes to the next generation. Our study was able to improve variety identification of Douglas-fir using isoenzyme markers and nuclear microsatellites and study reproductive patterns, both are important issues for the management of Douglas-fir stands in Bavaria.

  4. Defining old growth for fire-adapted forests of the Western United States

    Science.gov (United States)

    Merrill R. Kaufmann; Daniel Binkley; Peter Z. Fule; Johnson Marlin; Scott L. Stephens; Thomas W. Swetnam

    2007-01-01

    There are varying definitions of old-growth forests because of differences in environment and differing fire influence across the Intermountain West. Two general types of forests reflect the role of fire: 1) forests shaped by natural changes in structure and species makeup-plant succession-that are driven by competitive differences among species and individual trees...

  5. Biomass conversion and expansion factors in Douglas-fir stands of different planting density: variation according to individual growth and prediction equations

    International Nuclear Information System (INIS)

    Marziliano, P.A.; Menguzzato, G.; Scuderi, A.; Scalise, C.; Coletta, V.

    2017-01-01

    Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density. Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy. Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density. Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees. Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.

  6. Biomass conversion and expansion factors in Douglas-fir stands of different planting density: variation according to individual growth and prediction equations

    Energy Technology Data Exchange (ETDEWEB)

    Marziliano, P.A.; Menguzzato, G.; Scuderi, A.; Scalise, C.; Coletta, V.

    2017-11-01

    Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density. Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy. Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density. Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees. Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.

  7. Longleaf pine forests and woodlands: old growth under fire!

    Science.gov (United States)

    Joan L. Walker

    1999-01-01

    The author discusses a once widespread forest type of the Southeast – longleaf pine dominated forests and woodlands. This system depends on fire – more or less frequent, and often of low intensity. Because human-mediated landscape fragmentation has drastically changed the behavior of fire on longleaf pine dominated landscapes, these forests and woodlands will never be...

  8. Local adaptation in migrated interior Douglas-fir seedlings is mediated by ectomycorrhizas and other soil factors.

    Science.gov (United States)

    Pickles, Brian J; Twieg, Brendan D; O'Neill, Gregory A; Mohn, William W; Simard, Suzanne W

    2015-08-01

    Separating edaphic impacts on tree distributions from those of climate and geography is notoriously difficult. Aboveground and belowground factors play important roles, and determining their relative contribution to tree success will greatly assist in refining predictive models and forestry strategies in a changing climate. In a common glasshouse, seedlings of interior Douglas-fir (Pseudotsuga menziesii var. glauca) from multiple populations were grown in multiple forest soils. Fungicide was applied to half of the seedlings to separate soil fungal and nonfungal impacts on seedling performance. Soils of varying geographic and climatic distance from seed origin were compared, using a transfer function approach. Seedling height and biomass were optimized following seed transfer into drier soils, whereas survival was optimized when elevation transfer was minimised. Fungicide application reduced ectomycorrhizal root colonization by c. 50%, with treated seedlings exhibiting greater survival but reduced biomass. Local adaptation of Douglas-fir populations to soils was mediated by soil fungi to some extent in 56% of soil origin by response variable combinations. Mediation by edaphic factors in general occurred in 81% of combinations. Soil biota, hitherto unaccounted for in climate models, interacts with biogeography to influence plant ranges in a changing climate. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  9. Arthropod Diversity and Functional Importance in Old-Growth Forests of North America

    Directory of Open Access Journals (Sweden)

    Timothy Schowalter

    2017-03-01

    Full Text Available Old-growth forests have become rare in North America but provide habitat for unique assemblages of species that often are rare in younger forests. Insects and related arthropods reach their highest diversity in old-growth forests because of their stable moderate temperature and relative humidity and the rich variety of resources represented by high plant species richness and structural complexity. Old-growth arthropod assemblages typically are distinct from those in younger, managed forests. Major subcommunities include the arboreal community that is composed of a rich assemblage of herbivores, fungivores, and their associated predators and parasitoids that function to regulate primary production and nutrient fluxes, the stem zone community that includes bark- and wood-boring species and their associated predators and parasitoids that initiate the decomposition of coarse woody debris, and the forest floor community composed of a variety of detritivores, fungivores, burrowers, and their associated predators and parasitoids that are instrumental in litter decomposition. Insect outbreaks are relatively rare in old-growth forests, where the diversity of resources and predators limit population growth. In turn, insects contribute to plant diversity and limit primary production of host plant species, thereby promoting development of old-growth forest characteristics. Arthropods also provide important functions in decomposition and nutrient cycling that may be lost in younger, managed forests with limited provision of coarse woody debris and accumulated litter. Protection of remnant old-growth forests within the forest matrix may be particularly valuable for maintaining the diversity of plant and arthropod predators that can minimize outbreaks, thereby contributing to resilience to changing environmental conditions.

  10. Spatial aspects of tree mortality strongly differ between young and old-growth forests.

    Science.gov (United States)

    Larson, Andrew J; Lutz, James A; Donato, Daniel C; Freund, James A; Swanson, Mark E; HilleRisLambers, Janneke; Sprugel, Douglas G; Franklin, Jerry F

    2015-11-01

    Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (old) and old-growth (> 300-year-old) Abies amabilis forests. Trees in young forests died at a rate of 4.42% per year, whereas trees in old-growth forests died at 0.60% per year. Tree mortality in young forests was significantly aggregated, strongly density dependent, and caused live tree patterns to become more uniform through time. Mortality in old-growth forests was spatially aggregated, but was density independent and did not change the spatial pattern of surviving trees. These results extend current theory by demonstrating that density-dependent competitive mortality leading to increasingly uniform tree spacing in young forests ultimately transitions late in succession to a more diverse tree mortality regime that maintains spatial heterogeneity through time.

  11. The Role of Old-growth Forests in Frequent-fire Landscapes

    Directory of Open Access Journals (Sweden)

    Daniel Binkley

    2007-12-01

    Full Text Available Classic ecological concepts and forestry language regarding old growth are not well suited to frequent-fire landscapes. In frequent-fire, old-growth landscapes, there is a symbiotic relationship between the trees, the understory graminoids, and fire that results in a healthy ecosystem. Patches of old growth interspersed with younger growth and open, grassy areas provide a wide variety of habitats for animals, and have a higher level of biodiversity. Fire suppression is detrimental to these forests, and eventually destroys all old growth. The reintroduction of fire into degraded frequent-fire, old-growth forests, accompanied by appropriate thinning, can restore a balance to these ecosystems. Several areas require further research and study: 1 the ability of the understory to respond to restoration treatments, 2 the rate of ecosystem recovery following wildfires whose level of severity is beyond the historic or natural range of variation, 3 the effects of climate change, and 4 the role of the microbial community. In addition, it is important to recognize that much of our knowledge about these old-growth systems comes from a few frequent-fire forest types.

  12. Foliar and ecosystem respiration in an old-growth tropical rain forest

    Science.gov (United States)

    Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

    2008-01-01

    Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI).A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (...

  13. Differences in Townsend's chipmunk populations between second- and old-growth forests in western Oregon

    Science.gov (United States)

    D.K. Rosenberg; R.G. Anthony

    1993-01-01

    Because Townsend's chipmunks (Tomias townsendii) may be important in maintaining natural ecosystem processes in forests in the central Oregon Cascade Range, we compared their population characteristics in young second-growth and old-growth forests. We live-trapped Townsend's chipmunks in 5 young (30-60 yr old) second-growth and 5 old-...

  14. Seasonal patterns of bole water content in old growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)

    Science.gov (United States)

    Large, old conifer trees in the Pacific Northwest (PNW), USA purportedly ameliorate the effects of seasonal summer drought by drawing down the water content of bole tissues over the summer months and refilling during the winter. Continuous monitoring of bole relative water conten...

  15. A SNP resource for Douglas-fir: de novo transcriptome assembly and SNP detection and validation.

    Science.gov (United States)

    Howe, Glenn T; Yu, Jianbin; Knaus, Brian; Cronn, Richard; Kolpak, Scott; Dolan, Peter; Lorenz, W Walter; Dean, Jeffrey F D

    2013-02-28

    Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauca) are native to North America, the coastal variety is also widely planted for timber production in Europe, New Zealand, Australia, and Chile. Our main goal was to develop a SNP resource large enough to facilitate genomic selection in Douglas-fir breeding programs. To accomplish this, we developed a 454-based reference transcriptome for coastal Douglas-fir, annotated and evaluated the quality of the reference, identified putative SNPs, and then validated a sample of those SNPs using the Illumina Infinium genotyping platform. We assembled a reference transcriptome consisting of 25,002 isogroups (unique gene models) and 102,623 singletons from 2.76 million 454 and Sanger cDNA sequences from coastal Douglas-fir. We identified 278,979 unique SNPs by mapping the 454 and Sanger sequences to the reference, and by mapping four datasets of Illumina cDNA sequences from multiple seed sources, genotypes, and tissues. The Illumina datasets represented coastal Douglas-fir (64.00 and 13.41 million reads), interior Douglas-fir (80.45 million reads), and a Yakima population similar to interior Douglas-fir (8.99 million reads). We assayed 8067 SNPs on 260 trees using an Illumina Infinium SNP genotyping array. Of these SNPs, 5847 (72.5%) were called successfully and were polymorphic. Based on our validation efficiency, our SNP database may contain as many as ~200,000 true SNPs, and as many as ~69,000 SNPs that could be genotyped at ~20,000 gene loci using an Infinium II array-more SNPs than are needed to use genomic selection in tree breeding programs. Ultimately, these genomic resources will enhance Douglas-fir breeding and allow us to better understand landscape-scale patterns of genetic variation and potential responses to

  16. Douglas-fir displays a range of growth responses to temperature, water, and Swiss needle cast in western Oregon, USA

    Science.gov (United States)

    Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC ...

  17. Growth of bear-damaged trees in a mixed plantation of Douglas-fir and red alder.

    Science.gov (United States)

    Richard E. Miller; Harry W. Anderson; Donald L. Reukema; Timothy A. Max

    2007-01-01

    Incidence and effects of tree damage by black bear (Ursus americanus altifrontalis) in a 50-year-old, coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantation are described. Bears girdled or partially girdled 35 dominant or codominant Douglas-fir trees per acre, but only in that...

  18. Changes in wood product proportions in the Douglas-fir region with respect to size, age, and time.

    Science.gov (United States)

    R.A. Monserud; X. Zhou

    2007-01-01

    We examine both the variation and the changing proportions of different wood products obtained from trees and logs in the Douglas-fir region of the Northwestern United States. Analyses are based on a large product recovery database covering over 40 years of recovery studies; 13 studies are available for Douglas-fir (Pseudotsuga menziesii (Mirb.)...

  19. An examination of the genetic control of Douglas-fir vascular tissue phytochemicals: implications for black bear foraging.

    Science.gov (United States)

    Bruce A. Kimball; G.R. Johnson; Dale L. Nolte; Doreen L. Griffin

    1999-01-01

    Silvicultural practices can influence black bear (Ursus americanus) foraging preferences for Douglas-fir (Pseudotsuga menziesii) cambial-zone vascular tissues, but little is known about the role of genetics. To study the impact of genetic selection, vascular tissue samples were collected from Douglas-fir trees in six half-sib families from five...

  20. Historical effects of dissolved organic carbon export and land management decisions on the watershed-scale forest carbon budget of a coastal British Columbia Douglas-fir-dominated landscape.

    Science.gov (United States)

    Smiley, B P; Trofymow, J A

    2017-12-01

    To address how natural disturbance, forest harvest, and deforestation from reservoir creation affect landscape-level carbon (C) budgets, a retrospective C budget for the 8500 ha Sooke Lake Watershed (SLW) from 1911 to 2012 was developed using historical spatial inventory and disturbance data. To simulate forest C dynamics, data was input into a spatially-explicit version of the Carbon Budget Model-Canadian Forest Sector (CBM-CFS3). Transfers of terrestrial C to inland aquatic environments need to be considered to better capture the watershed scale C balance. Using dissolved organic C (DOC) and stream flow measurements from three SLW catchments, DOC load into the reservoir was derived for a 17-year period. C stocks and stock changes between a baseline and two alternative management scenarios were compared to understand the relative impact of successive reservoir expansions and sustained harvest activity over the 100-year period. Dissolved organic C flux for the three catchments ranged from 0.017 to 0.057 Mg C ha -1  year -1 . Constraining CBM-CFS3 to observed DOC loads required parameterization of humified soil C losses of 2.5, 5.5, and 6.5%. Scaled to the watershed and assuming none of the exported terrestrial DOC was respired to CO 2 , we hypothesize that over 100 years up to 30,657 Mg C may have been available for sequestration in sediment. By 2012, deforestation due to reservoir creation/expansion resulted in the watershed forest lands sequestering 14 Mg C ha -1 less than without reservoir expansion. Sustained harvest activity had a substantially greater impact, reducing forest C stores by 93 Mg C ha -1 by 2012. However approximately half of the C exported as merchantable wood during logging (~176,000 Mg C) may remain in harvested wood products, reducing the cumulative impact of forestry activity from 93 to 71 Mg C ha -1 . Dissolved organic C flux from temperate forest ecosystems is a small but persistent C flux which may have long term

  1. Historical effects of dissolved organic carbon export and land management decisions on the watershed-scale forest carbon budget of a coastal British Columbia Douglas-fir-dominated landscape

    Directory of Open Access Journals (Sweden)

    B. P. Smiley

    2017-07-01

    Full Text Available Abstract Background To address how natural disturbance, forest harvest, and deforestation from reservoir creation affect landscape-level carbon (C budgets, a retrospective C budget for the 8500 ha Sooke Lake Watershed (SLW from 1911 to 2012 was developed using historical spatial inventory and disturbance data. To simulate forest C dynamics, data was input into a spatially-explicit version of the Carbon Budget Model-Canadian Forest Sector (CBM-CFS3. Transfers of terrestrial C to inland aquatic environments need to be considered to better capture the watershed scale C balance. Using dissolved organic C (DOC and stream flow measurements from three SLW catchments, DOC load into the reservoir was derived for a 17-year period. C stocks and stock changes between a baseline and two alternative management scenarios were compared to understand the relative impact of successive reservoir expansions and sustained harvest activity over the 100-year period. Results Dissolved organic C flux for the three catchments ranged from 0.017 to 0.057 Mg C ha−1 year−1. Constraining CBM-CFS3 to observed DOC loads required parameterization of humified soil C losses of 2.5, 5.5, and 6.5%. Scaled to the watershed and assuming none of the exported terrestrial DOC was respired to CO2, we hypothesize that over 100 years up to 30,657 Mg C may have been available for sequestration in sediment. By 2012, deforestation due to reservoir creation/expansion resulted in the watershed forest lands sequestering 14 Mg C ha−1 less than without reservoir expansion. Sustained harvest activity had a substantially greater impact, reducing forest C stores by 93 Mg C ha−1 by 2012. However approximately half of the C exported as merchantable wood during logging (~176,000 Mg C may remain in harvested wood products, reducing the cumulative impact of forestry activity from 93 to 71 Mg C ha−1. Conclusions Dissolved organic C flux from temperate forest ecosystems is a

  2. Biomass and water storage dynamics of epiphytes in old-growth and secondary montane cloud forest stands in Costa Rica

    NARCIS (Netherlands)

    Koehler, L.; Tobon, C.; Frumau, K.F.A.; Bruijnzeel, L.A.

    2007-01-01

    Epiphytic biomass, canopy humus and associated canopy water storage capacity are known to vary greatly between old-growth tropical montane cloud forests but for regenerating forests such data are virtually absent. The present study was conducted in an old-growth cloud forest and in a 30-year-old

  3. Historical harvests reduce neighboring old-growth basal area across a forest landscape.

    Science.gov (United States)

    Bell, David M; Spies, Thomas A; Pabst, Robert

    2017-07-01

    While advances in remote sensing have made stand, landscape, and regional assessments of the direct impacts of disturbance on forests quite common, the edge influence of timber harvesting on the structure of neighboring unharvested forests has not been examined extensively. In this study, we examine the impact of historical timber harvests on basal area patterns of neighboring old-growth forests to assess the magnitude and scale of harvest edge influence in a forest landscape of western Oregon, USA. We used lidar data and forest plot measurements to construct 30-m resolution live tree basal area maps in lower and middle elevation mature and old-growth forests. We assessed how edge influence on total, upper canopy, and lower canopy basal area varied across this forest landscape as a function of harvest characteristics (i.e., harvest size and age) and topographic conditions in the unharvested area. Upper canopy, lower canopy, and total basal area increased with distance from harvest edge and elevation. Forests within 75 m of harvest edges (20% of unharvested forests) had 4% to 6% less live tree basal area compared with forest interiors. An interaction between distance from harvest edge and elevation indicated that elevation altered edge influence in this landscape. We observed a positive edge influence at low elevations (800 m). Surprisingly, we found no or weak effects of harvest age (13-60 yr) and harvest area (0.2-110 ha) on surrounding unharvested forest basal area, implying that edge influence was relatively insensitive to the scale of disturbance and multi-decadal recovery processes. Our study indicates that the edge influence of past clearcutting on the structure of neighboring uncut old-growth forests is widespread and persistent. These indirect and diffuse legacies of historical timber harvests complicate forest management decision-making in old-growth forest landscapes by broadening the traditional view of stand boundaries. Furthermore, the consequences

  4. Conserving and Restoring Old Growth in Frequent-fire Forests: Cycles of Disruption and Recovery

    Directory of Open Access Journals (Sweden)

    Dave Egan

    2007-12-01

    Full Text Available I provide a synthesis of the papers in the Special Issue, The Conservation and Restoration of Old Growth in Frequent-fire Forests of the American West. These papers - the product of an Old Growth Writing Workshop, held at Northern Arizona University in Flagstaff, Arizona on 18-19 April 2006 - represent the ideas of 25 workshop participants who argue for a new attitude toward managing old growth in the frequent-fire forests of the American West. Unlike the lush, old-growth rainforests of the Pacific Northwest, the dry, frequent-fire forests of the western United States evolved with surface fires that disturbed the system with such regularity that young trees were almost always killed. When saplings did survive, they grew beyond the harm of frequent surface fires and, ultimately, attained the characteristics that define old growth in these systems. This system worked well, producing old-growth trees in abundance, until the onset of Euro-American settlement in the mid- to late-19th century. The arrival of these settlers put in motion an interplay of unprecedented social, political, economic, and ecological forces (e.g., removal of Native Americans and their fire-based land management systems, overgrazing of the understory, aggressive logging, establishment of federal land management agencies, implementation of a federal fire suppression policy. These activities have culminated in 1 overly dense forested ecosystems that are now on the verge of collapse because of catastrophic fires (i.e., crown fire at the landscape level; the Rodeo-Chediski Fire and insect outbreaks, 2 the emergence of conservation-minded environmental legislation and policy, and 3 greater levels of interaction between citizens, federal agencies, and fire-prone landscapes. Recognizing the tenuous ecological situation of these forests, restoration ecologists, foresters, and others have developed ways to return historic ecological processes and lower tree densities to these forests

  5. Effect of stand edge on the natural regeneration of spruce, beech and Douglas-fir

    Directory of Open Access Journals (Sweden)

    Lumír Dobrovolný

    2012-01-01

    Full Text Available Our work aimed at studying the strategy of woody plants regeneration during the regeneration of a spruce stand with the admixture of beech and Douglas-fir by border cutting (NW-SE aspect on acidic sites of higher elevations in the Bohemian-Moravian Upland. Spruce is better adapted to bear shade than Douglas-fir. Nevertheless, in optimal light conditions up to a distance of ca. 35 m (about 16% DIFFSF from the stand edge, the Douglas-fir can put the spruce into danger as to height growth. By contrast to beech, the density of spruce is significantly higher within the distance of 45 m (about 15% DIFFSF from the stand edge but further on the situation would change to the benefit of beech. The density of Douglas-fir significantly dominates over beech within a distance of 35 m from the stand edge; from 55 m (less than 15% DIFFSF, the situation changes in favour of beech. Beech can survive in full shade deep in the stand core waiting for its opportunity to come. As compared to spruce and Douglas-fir, the height growth of beech was at all times significantly greater at a distance of 25 m from the stand edge. Converted to practical conditions, spruce and Douglas-fir with individually admixed beech seedlings showed good prosperity approximately up to a distance of one stand height from the edge. A mixture of spruce and beech did well at a greater distance but good prosperity at a distance of 2–3 stand heights was shown only by beech. Thus, border regeneration eliminates disadvantages of the climatic extremes of clear-cutting and specifics of shelterwood felling during which one – usually shade-tolerant tree species dominates in the natural regeneration (e.g. beech.

  6. Tree dynamics in canopy gaps in old-growth forests of Nothofagus pumilio in Southern Chile

    NARCIS (Netherlands)

    Fajardo, Alex; Graaf, de N.R.

    2004-01-01

    The gap dynamics of two Nothofagus pumilio (lenga) stands have been investigated. We evaluated and compared tree diameter distributions, spatial patterns, tree fall and gap characteristics and regeneration responses in gaps in two old-growth forests of Nothofagus pumilio in Southern Chile

  7. Notes on Some Old-Growth Forests in Ohio, Indiana, and Illinois

    Science.gov (United States)

    John T. Auten

    1941-01-01

    The disturbing increase in acreage of abandoned land in the Central States has heightened interest in the region's few remnants of old-growth hardwood forest. Studies are being made to determine what kinds of trees originally grew on different kinds of soil, what was the original character of the soil, how many trees grew on an acre, and how large the trees were...

  8. Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink.

    Science.gov (United States)

    McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H

    2015-02-01

    Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.

  9. Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscape.

    Science.gov (United States)

    Rocha, Ricardo; Ovaskainen, Otso; López-Baucells, Adrià; Farneda, Fábio Z; Sampaio, Erica M; Bobrowiec, Paulo E D; Cabeza, Mar; Palmeirim, Jorge M; Meyer, Christoph F J

    2018-02-28

    Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes.

  10. Plot size recommendations for biomass estimation in a midwestern old-growth forest

    Science.gov (United States)

    Martin A. Spetich; George R Parker

    1998-01-01

    The authors examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. d.b.h. and greater has been tagged and mapped since 1926. Five windows of time are compared—1926, 1976, 1981, 1986...

  11. Ground beetles as indicators of past management of old-growth forests

    Directory of Open Access Journals (Sweden)

    Mazzei A

    2017-06-01

    Full Text Available Old-growth forests are terrestrial ecosystems with the highest level of biodiversity and the main environments for the study of conservation and dynamics of the forest system. In Mediterranean Europe, two millennia of human exploitation deeply altered the structural complexity of the native forests. Some animal groups, including insects, may be used as a proxy of such changes. In this paper we explored the possible effects of forest management on the functional diversity (species traits of carabid beetle communities. Three old-growth forests of the Sila National Park were sampled by pitfall traps set up in pure beech, beech-silver fir and Calabrian black pine forests. In each forest, five managed vs. five unmanaged stands were considered. Managed sites were exploited until the sixties of the past century and then left unmanaged. More than 6000 carabid specimens belonging to 23 species were collected. The functional diversity in carabid groups is influenced by forest management especially in beech and beech-silver fir stands. Body size, specialized predators, endemic species and forest species were negatively affected by stand management. On the contrary, omnivorous ground beetles populations (or species with a high dispersal power (macropterous and large geographic distribution were positively influenced by stand management. In pine forests the old-growth community seems less sensitive to past management and more affected by soil evolution. Soil erosion and disturbance may reduce species diversity of ground beetles. Anyway, the composition of the carabid community shows that 50-60 years of forest restoration are enough for the reconstruction of a fairly diverse assemblage reflecting a “subclimax” situation.

  12. Deriving Fuel Mass by Size Class in Douglas-fir (Pseudotsuga menziesii Using Terrestrial Laser Scanning

    Directory of Open Access Journals (Sweden)

    Lloyd Queen

    2011-08-01

    Full Text Available Requirements for describing coniferous forests are changing in response to wildfire concerns, bio-energy needs, and climate change interests. At the same time, technology advancements are transforming how forest properties can be measured. Terrestrial Laser Scanning (TLS is yielding promising results for measuring tree biomass parameters that, historically, have required costly destructive sampling and resulted in small sample sizes. Here we investigate whether TLS intensity data can be used to distinguish foliage and small branches (≤0.635 cm diameter; coincident with the one-hour timelag fuel size class from larger branchwood (>0.635 cm in Douglas-fir (Pseudotsuga menziesii branch specimens. We also consider the use of laser density for predicting biomass by size class. Measurements are addressed across multiple ranges and scan angles. Results show TLS capable of distinguishing fine fuels from branches at a threshold of one standard deviation above mean intensity. Additionally, the relationship between return density and biomass is linear by fuel type for fine fuels (r2 = 0.898; SE 22.7% and branchwood (r2 = 0.937; SE 28.9%, as well as for total mass (r2 = 0.940; SE 25.5%. Intensity decays predictably as scan distances increase; however, the range-intensity relationship is best described by an exponential model rather than 1/d2. Scan angle appears to have no systematic effect on fine fuel discrimination, while some differences are observed in density-mass relationships with changing angles due to shadowing.

  13. Geographical Variation in the Terpene Composition of the Leaf Oil of Douglas Fir,

    Science.gov (United States)

    The two forms of Douglas fir, Pseudotsuga menziesii var. menziesii and var. glauca, differ quite considerably with regard to the monoterpenes of...their leaf oils. Several chemical races, differing quantitatively in certain monoterpenes , appear to exist in each variety and the leaf oil composition seems to be particularly useful in classifying intermediate forms. (Author)

  14. BOLE WATER CONTENT SHOWS LITTLE SEASONAL VARIATION IN CENTURY-OLD DOUGLAS-FIR TREES

    Science.gov (United States)

    Purportedly, large Douglas-fir trees in the American Pacific Northwest use water stored in bole tissues to ameliorate the effects of seasonal summer drought, the water content of bole tissues being drawn down over the summer months and replenished during the winter. Continuous mo...

  15. Stump-to-truck cable logging cost equations for young-growth douglas-fir

    Science.gov (United States)

    Chris B. LeDoux; Roger D. Fight; Tom L. Ortman

    1986-01-01

    Logging cost simulators and data from logging cost studies have been assembled and converted into a series of equations that can be used to estimate the cost of logging young-growth coastal Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) in mountainous terrain of the Pacific Northwest. These equations were...

  16. Regional patterns of increasing Swiss needle cast impacts on Douglas-fir growth with warming temperatures.

    Science.gov (United States)

    The fungal pathogen, Phaeocryptopus gaeumannii, occurs wherever Douglas-fir is found but disease damage is believed to be limited in the Pacific Northwest (PNW) to the Oregon Coast Range and is of no concern outside the coastal fog zone [1]. However, knowledge remains limited on...

  17. Estimating biomass of shrubs and forbs in central Washington Douglas-fir stands.

    Science.gov (United States)

    Craig M. Olson; Robert E. Martin

    1981-01-01

    Understory plants in closed 70-year-old even-aged Douglas-fir stands in north central Washington were destructively sampled to determine the relationship of ground cover and height to dry weight. Weight of plant material can be estimated from the product of plant height and percentage of ground cover on 50- x 100-centimeter (cm) quadrats. Correlation coefficients for...

  18. The Douglas-fir genome sequence reveals specialization of the photosynthetic apparatus in Pinaceae

    Science.gov (United States)

    David B. Neale; Patrick E. McGuire; Nicholas C. Wheeler; Kristian A. Stevens; Marc W. Crepeau; Charis Cardeno; Aleksey V. Zimin; Daniela Puiu; Geo M. Pertea; U. Uzay Sezen; Claudio Casola; Tomasz E. Koralewski; Robin Paul; Daniel Gonzalez-Ibeas; Sumaira Zaman; Richard Cronn; Mark Yandell; Carson Holt; Charles H. Langley; James A. Yorke; Steven L. Salzberg; Jill L. Wegrzyn

    2017-01-01

    A reference genome sequence for Pseudotsuga menziesii var. menziesii (Mirb.) Franco (Coastal Douglas-fir) is reported, thus providing a reference sequence for a third genus of the family Pinaceae. The contiguity and quality of the genome assembly far exceeds that of other conifer reference genome sequences (contig N50 = 44,136 bp and scaffold N50...

  19. Prescribed fire opportunities in grasslands invaded by Douglas-fir: state-of-the-art guidelines

    Science.gov (United States)

    George E. Gruell; James K. Brown; Charles L. Bushey

    1986-01-01

    Provides information on use of prescribed fire to enhance productivity of bunchgrass ranges that have been invaded by Douglas-fir. Six vegetative "situations" representative of treatment opportunities most commonly encountered in Montana are discussed. Included are fire prescription considerations and identification of the resource objective, fire objective,...

  20. Effects of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) wood

    Science.gov (United States)

    Xianjun Li; Zhiyong Cai; Qunying Mou; Yiqiang Wu; Yuan Liu

    2011-01-01

    In this study the effect of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) was investigated. Wood specimens were subjected to heat treatment at 160, 180, 200 and 220°C for 1, 2, 3 and 4h. The results show that heat treatment resulted in a darkened color, decreased moisture performance and increased dimensional stability of...

  1. Volume growth trends in a Douglas-fir levels-of-growing-stock study.

    Science.gov (United States)

    Robert O. Curtis

    2006-01-01

    Mean curves of increment and yield in gross total cubic volume and net merchantable cubic volume were derived from seven installations of the regional cooperative Levels-of-Growing-Stock Study (LOGS) in Douglas-fir. The technique used reduces the seven curves for each treatment for each variable of interest to a single set of readily interpretable mean curves. To a top...

  2. Pest management in Douglas-fir seed orchards: a microcomputer decision method

    Science.gov (United States)

    James B. Hoy; Michael I. Haverty

    1988-01-01

    The computer program described provides a Douglas-fir seed orchard manager (user) with a quantitative method for making insect pest management decisions on a desk-top computer. The decision system uses site-specific information such as estimates of seed crop size, insect attack rates, insecticide efficacy and application costs, weather, and crop value. At sites where...

  3. Growth and morphogenesis of shoot initials of Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, in vitro

    NARCIS (Netherlands)

    Evers, P.W.

    1984-01-01

    An optimalized method of micropropagation of Douglas fir is described. Seasonal changes were found in optima for nitrate and sucrose in the medium and in the optimum for the light intensity during the culture of shoot initials. Differences in morphogenesis were obtained from shoot initials that had

  4. Foliar essential oils and deer browsing preference of Douglas-fir genotypes

    Science.gov (United States)

    M.A. Radwan

    1978-01-01

    Yield and composition of essential oils were compared in foliage of Douglas-fir. Five clones with different susceptibilities to deer browsing were used; foliage was collected during the dormant season. There were no qualitative differences among the oils of the different clones, but the oils differed quantitatively in all variables measured. Eight variables appeared...

  5. Effectiveness of fungicides in protecting Douglas-fir shoots from infection by Phytophthora ramorum

    Science.gov (United States)

    G.A. Chastagner; E.M. Hansen; K.L. Riley; W. Sutton

    2006-01-01

    The effectiveness of 20 systemic and contact fungicides in protecting Douglas-fir seedlings from infection by Phytophthora ramorum was determined. Some systemic products were applied about a week prior to bud break, while most treatments were applied just after bud break. In addition to the fungicides, two surfactants were included in the post-bud...

  6. Growth phenology of coast Douglas-fir seed sources planted in diverse environments

    Science.gov (United States)

    Peter J. Gould; Constance A. Harrington; J. Bradley St. Clair

    2012-01-01

    The timing of periodic life cycle events in plants (phenology) is an important factor determining how species and populations will react to climate change. We evaluated annual patterns of basal-area and height growth of coast Douglas-fir (Pseudotusuga menziesii var. menziesii (Mirb.) Franco) seedlings from four seed sources...

  7. DFSIM with economics: A financial analysis option for the DFSIM Douglas-fir simulator.

    Science.gov (United States)

    Roger O. Fight; Judith M. Chittester; Gary W. Clendenen

    1984-01-01

    A modified version of the DFSIM Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and yield simulator, DFSIM WITH ECONOMICS, now has an economics option that allows the user to estimate present net worth at the same time a silvicultural regime is simulated. If desired, the economics option will apply a...

  8. Physiological responses of planting frozen and thawed Douglas-fir seedlings

    Science.gov (United States)

    M. Anisul Islam; Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2008-01-01

    We studied the short-term (7-day) physiological responses of planting thawed and frozen root plugs of Douglas-fir (Pseudotsuga menziesii) seedlings in 2 separate experiments under cool-moist and warm-dry growing conditions, respectively. Our results showed that shoot water potential, root hydraulic conductance, net photosynthesis (A), and...

  9. Realized gains from block-plot coastal Douglas-fir trials in the northern Oregon Cascades

    Science.gov (United States)

    Terrence Z. Ye; Keith J.S. Jayawickrama; J. Bradley. St. Clair

    2010-01-01

    Realized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite--high predicted gain; intermediate--moderate predicted gain; and an...

  10. Morphology and accumulation of epicuticular wax on needles of Douglas-fir (Pseudotsuga menziesii var. menziesii)

    Science.gov (United States)

    Constance A. Harrington; William C. Carlson

    2015-01-01

    Past studies have documented differences in epicuticular wax among several tree species but little attention has been paid to changes in accumulation of foliar wax that can occur during the year. We sampled current-year needles from the terminal shoots of Douglas-fir (Pseudotsuga menziesii var. menziesii) in late June/early...

  11. Early genetic evaluation of open-pollinated Douglas-fir families

    Science.gov (United States)

    Kurt H. Riitters; David A. Perry

    1987-01-01

    In a test of early genetic evaluation of the growth potential of 14 families of open-pollinated Douglas-fir (Pseudotsuga menziesii) [Mirb.] Franco), measures of growth and phenology of seedligns grown in a coldframe were correlated with height of saplings in evaluation plantations at 9, 12, and 15 years. fifteen-year height was most strongly...

  12. The Douglas-Fir Genome Sequence Reveals Specialization of the Photosynthetic Apparatus in Pinaceae

    Directory of Open Access Journals (Sweden)

    David B. Neale

    2017-09-01

    Full Text Available A reference genome sequence for Pseudotsuga menziesii var. menziesii (Mirb. Franco (Coastal Douglas-fir is reported, thus providing a reference sequence for a third genus of the family Pinaceae. The contiguity and quality of the genome assembly far exceeds that of other conifer reference genome sequences (contig N50 = 44,136 bp and scaffold N50 = 340,704 bp. Incremental improvements in sequencing and assembly technologies are in part responsible for the higher quality reference genome, but it may also be due to a slightly lower exact repeat content in Douglas-fir vs. pine and spruce. Comparative genome annotation with angiosperm species reveals gene-family expansion and contraction in Douglas-fir and other conifers which may account for some of the major morphological and physiological differences between the two major plant groups. Notable differences in the size of the NDH-complex gene family and genes underlying the functional basis of shade tolerance/intolerance were observed. This reference genome sequence not only provides an important resource for Douglas-fir breeders and geneticists but also sheds additional light on the evolutionary processes that have led to the divergence of modern angiosperms from the more ancient gymnosperms.

  13. Effects of water suspension and wet-dry cycling on fertility of Douglas-fir pollen.

    Science.gov (United States)

    Donald L. Copes; Nan C. Vance

    2000-01-01

    Studies were made to determine how long Douglas-fir pollen remains viable after suspension in cool water form 0 to 34 days. Linear regression analysis of in vivo and in vitro tests indicated that filled seed efficiency and pollen viability, respectively, decreased about 3 percent per day. The relation may have been nonlinear the first 6 days, as little decrease...

  14. Use of dominant tree heights in determining site index for Douglas-fir.

    Science.gov (United States)

    George R. Staebler

    1948-01-01

    Measuring heights of Douglas-fir trees for the determination of site index is a time-consuming job, especially in dense stands. Both dominant and codominant trees must be measured since site index curves represent the average height of dominants and codominants. It has been suggested that considerable time might be saved if only dominant trees were measured, since...

  15. Marbled Murrelets Select Distinctive Nest Trees within Old-Growth Forest Patches

    Directory of Open Access Journals (Sweden)

    Michael P. Silvergieter

    2011-12-01

    Full Text Available The coastal old-growth forests of North America's Pacific Coast are renowned both for their commercial and ecological value. This study adds to growing evidence that selective harvesting of the largest trees may have a disproportionate ecological impact. Marbled Murrelets (Brachyramphus marmoratus, a threatened species, nest almost exclusively in these old-growth forests. Detailed knowledge of nesting habitat selection provides guidance for habitat management and conservation. Habitat selection for this species has been studied at a variety of scales using ground and remote methods. However, because Marbled Murrelet nesting activity is limited to a single mossy platform on a single tree, we investigated nest tree selection within old-growth forest patches, using a set of 59 forest patches containing active nests. Nest trees were usually distinctive compared with neighboring trees in the surrounding 25 m radius patch. They averaged 15 to 20% taller than neighboring trees depending on region, had significantly larger stem diameters, more potential nesting platforms, and more moss. They had the most extreme values of height and width about three times as often as expected by chance. An analysis of moss platform use as a function of number of platforms per platform tree suggests that murrelets select individual platforms, rather than platform trees per se. Nonetheless, highly selective logging practices that remove high-value trees from stands may also remove trees most likely to be selected by nesting murrelets.

  16. Chemical composition of douglas-fir foliage on mule deer winter range. Research report No. RR 91003-CA

    Energy Technology Data Exchange (ETDEWEB)

    Waterhouse, M J; Armleder, H M; Dawson, R J

    1991-01-01

    In the interior of British Columbia, Douglas-fir litterfall is a major source of mule deer winter food. An earlier study found that preference for Douglas-fir foliage was correlated with tree diameter. This study identified the underlying factors of selection so that wildlife managers might have a wider range of forage enhancement options on mule deer winter range. Samples of Douglas-fir foliage were collected from trees at Knife Creek and Big Lake, and analyzed for minerals, tannins, and in vitro digestible dry matter.

  17. Ground cover in old-growth forests of the central hardwood region

    Science.gov (United States)

    Martin A. Spetich; Stephen R. Shifley; George R. Parker; Felix, Jr. Ponder

    1997-01-01

    Differences in ground cover (percent cover of litter, percent cover of vegetation and litter weight) in old-growth forests across this region are not well understood. We initiated a long-term study in a three-state region to enhance knowledge in this area. We present baseline results for ground cover and compare these data across productivity regions. Thirty 0.25-ac (0...

  18. Spatial models reveal the microclimatic buffering capacity of old-growth forests.

    Science.gov (United States)

    Frey, Sarah J K; Hadley, Adam S; Johnson, Sherri L; Schulze, Mark; Jones, Julia A; Betts, Matthew G

    2016-04-01

    Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming.

  19. Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile

    Directory of Open Access Journals (Sweden)

    Jan R. Bannister

    2013-11-01

    Full Text Available The Evergreen forest type develops along the Valdivian and North-Patagonian phytogeographical regions of the south-central part of Chile (38° S–46° S. These evergreen forests have been scarcely studied south of 43° S, where there is still a large area made up of old-growth forests. Silvicultural proposals for the Evergreen forest type have been based on northern Evergreen forests, so that the characterization of the structure and composition of southern Evergreen forests, e.g., their typification, would aid in the development of appropriate silvicultural proposals for these forests. Based on the tree composition of 46 sampled plots in old-growth forests in an area of >1000 ha in southern Chiloé Island (43° S, we used multivariate analyses to define forest groups and to compare these forests with other evergreen forests throughout the Archipelago of North-Patagonia. We determined that evergreen forests of southern Chiloé correspond to the North-Patagonian temperate rainforests that are characterized by few tree species of different shade tolerance growing on fragile soils. We discuss the convenience of developing continuous cover forest management for these forests, rather than selective cuts or even-aged management that is proposed in the current legislation. This study is a contribution to forest classification for both ecologically- and forestry-oriented purposes.

  20. Gap Dynamics and Structure of Two Old-Growth Beech Forest Remnants in Slovenia

    Science.gov (United States)

    Rugani, Tihomir; Diaci, Jurij; Hladnik, David

    2013-01-01

    Context Due to a long history of intensive forest exploitation, few European beech (Fagus sylvatica L.) old-growth forests have been preserved in Europe. Material and Methods We studied two beech forest reserves in southern Slovenia. We examined the structural characteristics of the two forest reserves based on data from sample plots and complete inventory obtained from four previous forest management plans. To gain a better understanding of disturbance dynamics, we used aerial imagery to study the characteristics of canopy gaps over an 11-year period in the Kopa forest reserve and a 20-year period in the Gorjanci forest reserve. Results The results suggest that these forests are structurally heterogeneous over small spatial scales. Gap size analysis showed that gaps smaller than 500 m2 are the dominant driving force of stand development. The percentage of forest area in canopy gaps ranged from 3.2 to 4.5% in the Kopa forest reserve and from 9.1 to 10.6% in the Gorjanci forest reserve. These forests exhibit relatively high annual rates of coverage by newly established (0.15 and 0.25%) and closed (0.08 and 0.16%) canopy gaps. New gap formation is dependant on senescent trees located throughout the reserve. Conclusion We conclude that these stands are not even-sized, but rather unevenly structured. This is due to the fact that the disturbance regime is characterized by low intensity, small-scale disturbances. PMID:23308115

  1. Variation in phenology and monoterpene patterns of defoliated and nondefoliated Douglas-fir (Pseudotsuga menziesii var. glauca).

    Science.gov (United States)

    Rose-Marie Muzika; Judith Engle; Catherine Parks; Boyd. Wickman

    1993-01-01

    Foliage was collected from paired Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees characterized as either "resistant" or "susceptible" western spruce budworm (Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) attack. Resistant trees produced more...

  2. The Tribal Perspective of Old Growth in Frequent-fire Forests - Its History

    Directory of Open Access Journals (Sweden)

    Victoria Yazzie

    2007-12-01

    Full Text Available Anyone who has not lived in "Indian country" cannot understand just how extensively the United States government and its laws affect Native Americans and their natural resource management. These effects are sobering, and touch upon sensitive issues that all Native Americans hold within us. In this article, I outline the historic cycle of tribal entities, and characterize today's tribal self-determination in forest management. I provide an historical account from the "colonial" period and its use of the Doctrine of Discovery to the relations between the United States government and Native Americans from the 18th through the 20th centuries, during which time Native Americans struggled to establish their legal status as tribes, and solidify their land base to sustain and conserve culturally important lands, including areas of old-growth forests, to the current self-determination and self-governance potential of Indian tribes. More importantly, I discuss the cultural connectivity that Native Americans have to the land, and address the unique inherent right of tribes to integrate this cultural view into current forest management, including the protection of old-growth forests, on their reservations.

  3. Complementary models of tree species-soil relationships in old-growth temperate forests

    Science.gov (United States)

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

  4. Variation in short-term and long-term responses of photosynthesis and isoprenoid-mediated photoprotection to soil water availability in four Douglas-fir provenances.

    Science.gov (United States)

    Junker, Laura Verena; Kleiber, Anita; Jansen, Kirstin; Wildhagen, Henning; Hess, Moritz; Kayler, Zachary; Kammerer, Bernd; Schnitzler, Jörg-Peter; Kreuzwieser, Jürgen; Gessler, Arthur; Ensminger, Ingo

    2017-01-10

    For long-lived forest tree species, the understanding of intraspecific variation among populations and their response to water availability can reveal their ability to cope with and adapt to climate change. Dissipation of excess excitation energy, mediated by photoprotective isoprenoids, is an important defense mechanism against drought and high light when photosynthesis is hampered. We used 50-year-old Douglas-fir trees of four provenances at two common garden experiments to characterize provenance-specific variation in photosynthesis and photoprotective mechanisms mediated by essential and non-essential isoprenoids in response to soil water availability and solar radiation. All provenances revealed uniform photoprotective responses to high solar radiation, including increased de-epoxidation of photoprotective xanthophyll cycle pigments and enhanced emission of volatile monoterpenes. In contrast, we observed differences between provenances in response to drought, where provenances sustaining higher CO 2 assimilation rates also revealed increased water-use efficiency, carotenoid-chlorophyll ratios, pools of xanthophyll cycle pigments, β-carotene and stored monoterpenes. Our results demonstrate that local adaptation to contrasting habitats affected chlorophyll-carotenoid ratios, pool sizes of photoprotective xanthophylls, β-carotene, and stored volatile isoprenoids. We conclude that intraspecific variation in isoprenoid-mediated photoprotective mechanisms contributes to the adaptive potential of Douglas-fir provenances to climate change.

  5. Structure and development of old-growth, unmanaged second-growth, and extended rotation Pinus resinosa forests in Minnesota, USA

    Science.gov (United States)

    Silver, Emily J.; D'Amato, Anthony W.; Fraver, Shawn; Palik, Brian J.; Bradford, John B.

    2013-01-01

    The structure and developmental dynamics of old-growth forests often serve as important baselines for restoration prescriptions aimed at promoting more complex structural conditions in managed forest landscapes. Nonetheless, long-term information on natural patterns of development is rare for many commercially important and ecologically widespread forest types. Moreover, the effectiveness of approaches recommended for restoring old-growth structural conditions to managed forests, such as the application of extended rotation forestry, has been little studied. This study uses several long-term datasets from old growth, extended rotation, and unmanaged second growth Pinus resinosa (red pine) forests in northern Minnesota, USA, to quantify the range of variation in structural conditions for this forest type and to evaluate the effectiveness of extended rotation forestry at promoting the development of late-successional structural conditions. Long-term tree population data from permanent plots for one of the old-growth stands and the extended rotation stands (87 and 61 years, respectively) also allowed for an examination of the long-term structural dynamics of these systems. Old-growth forests were more structurally complex than unmanaged second-growth and extended rotation red pine stands, due in large part to the significantly higher volumes of coarse woody debris (70.7 vs. 11.5 and 4.7 m3/ha, respectively) and higher snag basal area (6.9 vs. 2.9 and 0.5 m2/ha, respectively). In addition, old-growth forests, although red pine-dominated, contained a greater abundance of other species, including Pinus strobus, Abies balsamea, and Picea glauca relative to the other stand types examined. These differences between stand types largely reflect historic gap-scale disturbances within the old-growth systems and their corresponding structural and compositional legacies. Nonetheless, extended rotation thinning treatments, by accelerating advancement to larger tree diameter

  6. Manipulating stand structure of Douglas-fir plantations for wildlife habitat and wood production

    Science.gov (United States)

    Timothy B. Harrington

    2010-01-01

    In southwestern Oregon, a study was initiated by Oregon State University (OSU) in 1983 to determine effects of hardwood competition on Douglas-fir plantation development. The use of herbicides to uniformly suppress competing vegetation—especially fast-growing hardwoods—proved to be an effective approach to ensure dominance and a high level of productivity for planted...

  7. Plastic cages to protect Douglas-fir seedlings from animal damage in western Oregon.

    Science.gov (United States)

    Glen C. Crouch

    1980-01-01

    Effects of plastic mesh cages designed to protect Douglas-fir seedlings from animals were evaluated in western Oregon. In two tests over 5-year periods, caging increased survival by 0 and 13 percent and increased height growth by 0.8 and 1.2 feet compared with uncaged trees. Benefits from caging might have been greater if damage had been more prevalent during the tests...

  8. Automated knot detection with visual post-processing of Douglas-fir veneer images

    Science.gov (United States)

    C.L. Todoroki; Eini C. Lowell; Dennis Dykstra

    2010-01-01

    Knots on digital images of 51 full veneer sheets, obtained from nine peeler blocks crosscut from two 35-foot (10.7 m) long logs and one 18-foot (5.5 m) log from a single Douglas-fir tree, were detected using a two-phase algorithm. The algorithm was developed using one image, the Development Sheet, refined on five other images, the Training Sheets, and then applied to...

  9. Douglas-fir plantations in Europe: a retrospective test of assisted migration to address climate change.

    Science.gov (United States)

    Isaac-Renton, Miriam G; Roberts, David R; Hamann, Andreas; Spiecker, Heinrich

    2014-08-01

    We evaluate genetic test plantations of North American Douglas-fir provenances in Europe to quantify how tree populations respond when subjected to climate regime shifts, and we examined whether bioclimate envelope models developed for North America to guide assisted migration under climate change can retrospectively predict the success of these provenance transfers to Europe. The meta-analysis is based on long-term growth data of 2800 provenances transferred to 120 European test sites. The model was generally well suited to predict the best performing provenances along north-south gradients in Western Europe, but failed to predict superior performance of coastal North American populations under continental climate conditions in Eastern Europe. However, model projections appear appropriate when considering additional information regarding adaptation of Douglas-fir provenances to withstand frost and drought, even though the model partially fails in a validation against growth traits alone. We conclude by applying the partially validated model to climate change scenarios for Europe, demonstrating that climate trends observed over the last three decades warrant changes to current use of Douglas-fir provenances in plantation forestry throughout Western and Central Europe. © 2014 John Wiley & Sons Ltd.

  10. Defoliation of interior Douglas-fir elicits carbon transfer and stress signalling to ponderosa pine neighbors through ectomycorrhizal networks.

    Science.gov (United States)

    Song, Yuan Yuan; Simard, Suzanne W; Carroll, Allan; Mohn, William W; Zeng, Ren Sen

    2015-02-16

    Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change. To test whether defoliated IDF can directly transfer resources to ponderosa pine (Pinus ponderosae) regenerating nearby, thus aiding in forest recovery, we examined photosynthetic carbon transfer and defense enzyme response. We grew pairs of ectomycorrhizal IDF 'donor' and ponderosa pine 'receiver' seedlings in pots and isolated transfer pathways by comparing 35 μm, 0.5 μm and no mesh treatments; we then stressed IDF donors either through manual defoliation or infestation by the budworm. We found that manual defoliation of IDF donors led to transfer of photosynthetic carbon to neighboring receivers through mycorrhizal networks, but not through soil or root pathways. Both manual and insect defoliation of donors led to increased activity of peroxidase, polyphenol oxidase and superoxide dismutase in the ponderosa pine receivers, via a mechanism primarily dependent on the mycorrhizal network. These findings indicate that IDF can transfer resources and stress signals to interspecific neighbors, suggesting ectomycorrhizal networks can serve as agents of interspecific communication facilitating recovery and succession of forests after disturbance.

  11. Structure and development of old-growth, unmanaged second-growth, and extended rotation Pinus resinosa forests in Minnesota, USA

    Science.gov (United States)

    Emily J. Silver; Anthony W. D' Amato; Shawn Fraver; Brian J. Palik; John B. Bradford

    2013-01-01

    The structure and developmental dynamics of old-growth forests often serve as important baselines for restoration prescriptions aimed at promoting more complex structural conditions in managed forest landscapes. Nonetheless, long-term information on natural patterns of development is rare for many commercially important and ecologically widespread forest types....

  12. Upland log volumes and conifer establishment patterns in two northern, upland old-growth redwood forests, a brief synopsis

    Science.gov (United States)

    Daniel J. Porter; John O. Sawyer

    2007-01-01

    We characterized the volume, weight and top surface area of naturally fallen logs in an old-growth redwood forest, and quantified conifer recruit densities on these logs and on the surrounding forest floor. We report significantly greater conifer recruit densities on log substrates as compared to the forest floor. Log substrate availability was calculated on a per...

  13. Increase of an introduced bird competitor in old-growth forest associated with restoration

    Directory of Open Access Journals (Sweden)

    Leonard Freed

    2012-05-01

    Full Text Available Many successful invasions involve long initial periods in which the invader exists at low densities followed by sudden population increases. The reasons for such time-lags remain poorly understood. Here we document a sudden increase in density of the introduced Japanese white-eye (Zosterops japonicus in a restoration area contiguous with old-growth forest at Hakalau Forest National Wildlife Refuge on the Island of Hawaii. The refuge, with very high density of native birds, existed in a pocket of low white-eye density that persisted for at least 20 years since the late 1970s. The refuge began an extensive native trees restoration project in 1989 within a 1314 ha abandoned pasture above old-growth forest. This area was soon colonized by white-eyes and their population grew exponentially once the trees had grown tall enough to develop a canopy. This increase was in turn followed by significantly more white-eyes in the open and closed forests adjacent to the restoration area. Competition between white-eyes and native species was documented on study sites within these forests. Density data indicate that competition was more widespread, with loss of tens of thousands of native birds in the 5371 ha area surveyed. Our results are consistent with the view that ecological barriers may delay the population increase of invaders and that human-derived activities may help invaders cross these barriers by creating new ecological opportunities. Control of white-eye numbers may be essential for recovery of native species.

  14. Thirty-two years of change in an old-growth Ohio beech-maple forest.

    Science.gov (United States)

    Runkle, James R

    2013-05-01

    Old-growth forests dominated by understory-tolerant tree species are among forest types most likely to be in equilibrium. However, documentation of the degree to which they are in equilibrium over decades-long time periods is lacking. Changes in climate, pathogens, and land use all are likely to impact stand characteristics and species composition, even in these forests. Here, 32 years of vegetation changes in an old-growth beech (Fagus grandifolia)-sugar maple (Acer saccharum) forest in Hueston Woods, southwest Ohio, USA, are summarized. These changes involve canopy composition and structure, turnover in snags, and development of vegetation in treefall gaps. Stand basal area and canopy density have changed little in 32 years. However, beech has decreased in canopy importance (49% to 32%) while sugar maple has increased (32% to 47%). Annual mortality was about 1.3% throughout the study period. Mortality rates increased with stem size, but the fraction of larger stems increased due to ingrowth from smaller size classes. Beech was represented by more very large stems than small canopy stems: over time, death of those larger stems with inadequate replacement has caused the decrease in beech importance. Sugar maple was represented by more small canopy stems whose growth has increased its importance. The changes in beech and sugar maple relative importance are hypothesized to be due to forest fragmentation mostly from the early 1800s with some possible additional effects associated with the formation of the state park. Snag densities (12-16 snags/ha) and formation rates (1-3 snags.ha(-1).yr(-1)) remained consistent. The treefall gaps previously studied are closing, with a few, large stems remaining. Death of gap border trees occurs consistently enough to favor species able to combine growth in gaps and survival in the understory.

  15. Distribution of bioluminescent fungi across old-growth and secondary tropical rain forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolina Seas-Carvajal

    2013-06-01

    Full Text Available Most research on bioluminescent fungi is concentrated on their taxonomic relationships, while the basics of their natural history and ecological relationships are poorly understood. In this study, we compared the distribution of bioluminescent fungi between old-growth and secondary forest as related to four different soil types at the tropical rainforest of La Selva Biological Station in Costa Rica. The study was conducted during the wet season of 2009. Bioluminescent fungi were sought following eight different transects distributed evenly in old-growth and secondary forests across four different soil types, covering an area of 9 420m². We found fungi in four different substrates: litter, fallen branches, dead trunks, and roots, for a total of 61 samples. Correspondence analysis showed that the occurrence of fungi and soil types were related (inertia=0.21, p=0.071. We found a significant relationship between the presence of fungi and the distribution of soil types (X²=18.89, df=9, p=0.026. We found only three samples with fruiting bodies, two of which had Mycena and the other had one fungus of the order Xylariales (possibly Hypoxylon sp., Kretzschmariella sp., Xylaria sp.. Future work will concentrate on exploring other aspects of their ecology, such as their dispersal and substrate preference. This information will facilitate field identification and will foster more research on the distribution, seasonality, reproductive phenology and ecological requirements of this group of Fungi.

  16. Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

    Science.gov (United States)

    Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

    2009-01-01

    Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

  17. Crown plasticity and neighborhood interactions of European beech (Fagus sylvatica L.) in an old-growth forest

    NARCIS (Netherlands)

    Schröter, M.; Härdtle, W.; Oheimb, von G.

    2012-01-01

    Competition for canopy space is a process of major importance in forest dynamics. Although virgin and old-growth European beech (Fagus sylvatica L.) forests in Europe have been studied for many years, there are to date no studies of individual-tree crown plasticity and the way this is influenced by

  18. Restoring hydrology and old-growth structures in a former production forest

    DEFF Research Database (Denmark)

    Mazziotta, Adriano; Heilmann-Clausen, Jacob; Bruun, Hans Henrik

    2016-01-01

    to restore hydrology and old-growth structure. We collected presence/absence data for four organism groups (vascular plants, epiphytic bryophytes and lichens, wood-inhabiting fungi) and measured environmental variables associated with species occurrence and influenced by restoration (dead or living tree...... characteristics, stand age, water level). We investigated biodiversity consequences of restoration towards pristine environmental characteristics by using a space-for-time substitution model. We evaluated how and through what mechanisms species richness is likely to react when pre-forestry hydrological conditions......-restoration conditions. Furthermore, the increase in soil moisture shifted the forest plots towards an alder carr, while the stand ageing process sustained the shade-tolerant beech despite its low tolerance for high soil humidity. Our prediction shows an increase in species richness for plants directly driven...

  19. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO2 assimilation and growth in Douglas-fir

    Science.gov (United States)

    Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible...

  20. The contribution of competition to tree mortality in old-growth coniferous forests

    Science.gov (United States)

    Das, A.; Battles, J.; Stephenson, N.L.; van Mantgem, P.J.

    2011-01-01

    Competition is a well-documented contributor to tree mortality in temperate forests, with numerous studies documenting a relationship between tree death and the competitive environment. Models frequently rely on competition as the only non-random mechanism affecting tree mortality. However, for mature forests, competition may cease to be the primary driver of mortality.We use a large, long-term dataset to study the importance of competition in determining tree mortality in old-growth forests on the western slope of the Sierra Nevada of California, U.S.A. We make use of the comparative spatial configuration of dead and live trees, changes in tree spatial pattern through time, and field assessments of contributors to an individual tree's death to quantify competitive effects.Competition was apparently a significant contributor to tree mortality in these forests. Trees that died tended to be in more competitive environments than trees that survived, and suppression frequently appeared as a factor contributing to mortality. On the other hand, based on spatial pattern analyses, only three of 14 plots demonstrated compelling evidence that competition was dominating mortality. Most of the rest of the plots fell within the expectation for random mortality, and three fit neither the random nor the competition model. These results suggest that while competition is often playing a significant role in tree mortality processes in these forests it only infrequently governs those processes. In addition, the field assessments indicated a substantial presence of biotic mortality agents in trees that died.While competition is almost certainly important, demographics in these forests cannot accurately be characterized without a better grasp of other mortality processes. In particular, we likely need a better understanding of biotic agents and their interactions with one another and with competition. ?? 2011.

  1. Breakage or uprooting: How tree death type affects hillslope processes in old-growth temperate forests

    Science.gov (United States)

    Šamonil, Pavel; Daněk, Pavel; Adam, Dušan; Phillips, Jonathan D.

    2017-12-01

    Tree breakage and uprooting are two possible scenarios of tree death that have differing effects on hillslope processes. In this study we aimed to (i) reveal the long-term structure of the biomechanical effects of trees (BETs) in relation to their radial growth and tree death types in four old-growth temperate forests in four different elevation settings with an altitudinal gradient of 152-1105 m a.s.l., (ii) quantify affected areas and soil volumes associated with the studied BETs in reserves, and (iii) derive a general model of the role of BETs in hillslope processes in central European temperate forests. We analyzed the individual dynamics of circa 55,000 trees in an area of 161 ha within four old-growth forests over 3-4 decades. Basal tree censuses established in all sites in the 1970s and repeated tree censuses in the 1990s and 2000s provided detailed information about the radial growth of each tree of DBH ≥ 10 cm as well as about types of tree death. We focused on the quantification of: (i) surviving still-living trees, (ii) new recruits, (iii) standing dead trees, (iv) uprooted trees, and (v) broken trees. Frequencies of phenomena were related to affected areas and volumes of soil using individual statistical models. The elevation contrasts were a significant factor in the structure of BETs. Differences between sites increased from frequencies of events through affected areas to volumes of soil associated with BETs. An average 2.7 m3 ha-1 year-1 was associated with all BETs of the living and dying trees in lowlands, while there was an average of 7.8 m3 ha-1 year-1 in the highest mountain site. Differences were caused mainly by the effects of dying trees. BETs associated with dead trees were 7-8 times larger in the mountains. Effects of dying trees and particularly treethrows represented about 70% of all BETs at both mountain sites, while it was 58% at the highland site and only 32% at the lowland site. Our results show a more significant role of BETs in

  2. Regeneration Responses to Management for Old-Growth Characteristics in Northern Hardwood-Conifer Forests

    Directory of Open Access Journals (Sweden)

    Aviva J. Gottesman

    2017-02-01

    Full Text Available Successful tree regeneration is essential for sustainable forest management, yet it can be limited by the interaction of harvesting effects and multiple ecological drivers. In northern hardwood forests, for example, there is uncertainty whether low-intensity selection harvesting techniques will result in adequate and desirable regeneration. Our research is part of a long-term study that tests the hypothesis that a silvicultural approach called “structural complexity enhancement” (SCE can accelerate the development of late-successional forest structure and functions. Our objective is to understand the regeneration dynamics following three uneven-aged forestry treatments with high levels of retention: single-tree selection, group selection, and SCE. Regeneration density and diversity can be limited by differing treatment effects on or interactions among light availability, competitive environment, substrate, and herbivory. To explore these relationships, manipulations and controls were replicated across 2 ha treatment units at two Vermont sites. Forest inventory data were collected pre-harvest and periodically over 13 years post-harvest. We used mixed effects models with repeated measures to evaluate the effect of treatment on seedling and sapling density and diversity (Shannon–Weiner H’. The treatments were all successful in recruiting a sapling class with significantly greater sapling densities compared to the controls. However, undesirable and prolific beech (Fagus americana sprouting dominates some patches in the understory of all the treatments, creating a high degree of spatial variability in the competitive environment for regeneration. Multivariate analyses suggest that while treatment had a dominant effect, other factors were influential in driving regeneration responses. These results indicate variants of uneven-aged systems that retain or enhance elements of stand structural complexity—including old-growth characteristics

  3. The effect of size and competition on tree growth rate in old-growth coniferous forests

    Science.gov (United States)

    Das, Adrian

    2012-01-01

    Tree growth and competition play central roles in forest dynamics. Yet models of competition often neglect important variation in species-specific responses. Furthermore, functions used to model changes in growth rate with size do not always allow for potential complexity. Using a large data set from old-growth forests in California, models were parameterized relating growth rate to tree size and competition for four common species. Several functions relating growth rate to size were tested. Competition models included parameters for tree size, competitor size, and competitor distance. Competitive strength was allowed to vary by species. The best ranked models (using Akaike’s information criterion) explained between 18% and 40% of the variance in growth rate, with each species showing a strong response to competition. Models indicated that relationships between competition and growth varied substantially among species. The results also suggested that the relationship between growth rate and tree size can be complex and that how we model it can affect not only our ability to detect that complexity but also whether we obtain misleading results. In this case, for three of four species, the best model captured an apparent and unexpected decline in potential growth rate for the smallest trees in the data set.

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

    Directory of Open Access Journals (Sweden)

    David A. Perry

    2012-09-01

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

  5. Influence of competition and age on tree growth in structurally complex old-growth forests in northern Minnesota, USA

    Science.gov (United States)

    Tuomas Aakala; Shawn Fraver; Anthony W. D' Amato; Brian J. Palik

    2013-01-01

    Factors influencing tree growth in structurally complex forests remain poorly understood. Here we assessed the influence of competition on Pinus resinosa (n = 224) and Pinus strobus (n = 90) growth in four old-growth stands in Minnesota, using mixed effects models. A subset of trees, with...

  6. Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest

    Science.gov (United States)

    Siyan Ma; Jiquan Chen; John R. Butnor; Malcolm North; Eugénie S. Euskirchen; Brian Oakley

    2005-01-01

    Little is known about biophysical controls on soil respiration in California's Sierra Nevada old-growth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly...

  7. Tolerance to multiple climate stressors: A case study of Douglas-fir drought and cold hardiness

    Science.gov (United States)

    Bansal, Sheel; Harrington, Constance A; St. Clair, John Bradley

    2016-01-01

    Summary: 1. Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations. 2. We assessed the capacity of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii), an ecologically and economically important species in the northwestern USA, to tolerate both drought and cold stress on 35 populations grown in common gardens. We used principal components analysis to combine drought and cold hardiness trait data into generalized stress hardiness traits to model geographic variation in hardiness as a function of climate across the Douglas-fir range. 3. Drought and cold hardiness converged among populations along winter temperature gradients and diverged along summer precipitation gradients. Populations originating in regions with cold winters had relatively high tolerance to both drought and cold stress, which is likely due to overlapping adaptations for coping with winter desiccation. Populations from regions with dry summers had increased drought hardiness but reduced cold hardiness, suggesting a trade-off in tolerance mechanisms. 4. Our findings highlight the necessity to look beyond bivariate trait–climate relationships and instead consider multiple traits and climate variables to effectively model and manage for the impacts of climate change on widespread species.

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

    Science.gov (United States)

    Bolte, Andreas; Kampf, Friederike; Hilbrig, Lutz

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Andreas eBolte

    2013-08-01

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

  10. Local population extinction and vitality of an epiphytic lichen in fragmented old-growth forest.

    Science.gov (United States)

    Ockinger, Erik; Nilsson, Sven G

    2010-07-01

    The population dynamics of organisms living in short-lived habitats will largely depend on the turnover of habitat patches. It has been suggested that epiphytes, whose host plants can be regarded as habitat patches, often form such patch-tracking populations. However, very little is known about the long-term fate of epiphyte individuals and populations. We estimated life span and assessed environmental factors influencing changes in vitality, fertility, abundance, and distribution of the epiphytic lichen species Lobaria pulmonaria on two spatial scales, individual trees and forest patches, over a period of approximately 10 years in 66 old-growth forest fragments. The lichen had gone extinct from 7 of the 66 sites (13.0%) where it was found 10 years earlier, even though the sites remained unchanged. The risk of local population extinction increased with decreasing population size. In contrast to the decrease in the number of occupied trees and sites, the mean area of the lichen per tree increased by 43.0%. The number of trees with fertile ramets of L. pulmonaria increased from 7 (approximately 1%) to 61 (approximately 10%) trees, and the number of forest fragments with fertile ramets increased from 4 to 23 fragments. The mean annual rate of L. pulmonaria extinction at the tree level was estimated to be 2.52%, translating into an expected lifetime of 39.7 years. This disappearance rate is higher than estimated mortality rates for potential host trees. The risk of extinction at the tree level was significantly positively related to tree circumference and differed between tree species. The probability of presence of fertile ramets increased significantly with local population size. Our results show a long expected lifetime of Lobaria pulmonaria ramets on individual trees and a recent increase in vitality, probably due to decreasing air pollution. The population is, however, declining slowly even though remaining stands are left uncut, which we interpret as an

  11. Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO(2) assimilation and growth in Douglas-fir.

    Science.gov (United States)

    Saffell, Brandy J; Meinzer, Frederick C; Voelker, Steven L; Shaw, David C; Brooks, J Renée; Lachenbruch, Barbara; McKay, Jennifer

    2014-07-01

    Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years. © 2013 John Wiley & Sons Ltd.

  12. Pruning high-value Douglas-fir can reduce dwarf mistletoe severity and increase longevity in Central Oregon

    Science.gov (United States)

    Helen M. Maffei; Gregory M. Filip; Nancy E. Grulke; Brent W. Oblinger; Ellis Q. Margolis; Kristen L. Chadwick

    2016-01-01

    Mid- to very large-sized Douglas-fir (Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe (Arceuthobium douglasii) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without...

  13. The importance of seasonal temperature and moisture patterns on growth of Douglas-fir in western Oregon, USA

    Science.gov (United States)

    Douglas-fir growth in the Pacific Northwest is thought to be water limited. However, discerning the relative influence of air temperature and plant available soil water (W) on growth is difficult because they interact with each other, with other climate factors and with the inher...

  14. Regional effects of Swiss needle cast disease and climate on growth of Douglas-fir in western Oregon

    Science.gov (United States)

    The fungal pathogen, Phaeocryptopus gaeumannii, occurs wherever Douglas-fir is found but disease damage is believed to be limited to the Coast Range and is of no concern outside this region (Shaw et al., 2011). However, knowledge remains limited on the spatial distribution of Sw...

  15. Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca). IV. Montana and Idaho near the Continental Divide

    Science.gov (United States)

    Gerald Rehfeldt

    1988-01-01

    Seventy-seven seedling populations of Douglas-fir (Pseudotsuga menziesii var. glauca) sampled from near the Continental Divide in Idaho and Montana exhibited pronounced genetic differences when compared in three common environments. Differentiation involved several traits that are components of an annual developmental cycle that must be completed within a growing...

  16. Inheritance of restriction fragment length polymorphisms, random amplified polymorphic DNAs and isozymes in coastal Douglas-fir

    Science.gov (United States)

    K.D. Jermstad; A.M. Reem; J.R. Henifin; N.C. Wheeler; D.B Neale

    1994-01-01

    A total of 225 new genetic loci [151 restriction fragment length polymorphisms (RFLP) and 74 random amplified polymorphic DNAs (RAPD)] in coastal Douglas- fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii] have been identified using a three-generation outbred pedigree. The Mendelian inheritance of 16 RFLP loci and 29...

  17. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 18--Rocky Brook, 1963-2006.

    Science.gov (United States)

    Robert O. Curtis; David D. Marshall

    2009-01-01

    This report documents the history and results of the Rocky Brook installation of the cooperative levels-of-growing-stock (LOGS) study in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), over the 41-year period 1965 to 2006. This 1938 plantation is one of the two site-IV installations among the nine installations in the study. Much public...

  18. A strategy for monitoring Swiss needle cast and assessing its growth impact in Douglas-fir plantations of Coastal Oregon

    Science.gov (United States)

    Doug Maguire; Alan Kanaskie; Mike McWilliams

    2000-01-01

    Many Douglas-fir plantations along the north coast of Oregon are exhibiting severe symptoms of Swiss needle cast disease (SNC). These symptoms include premature loss of foliage, abundant fungal pseudothecia on needles, yellowing of foliage, and apparent reduction in diameter and height growth. The development of the disease and its impacts on growth are currently being...

  19. History of fire and Douglas-fir establishment in a savanna and sagebrush-grassland mosaic, southwestern Montana, USA

    Science.gov (United States)

    Emily K. Heyerdahl; Richard F. Miller; Russell A. Parsons

    2006-01-01

    Over the past century, trees have encroached into grass- and shrublands across western North America. These include Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco) encroaching into mountain big sagebrush Nutt. ssp. vaseyana (Rydb.) Beetle) from stable islands of savanna in...

  20. Slow and fast pyrolysis of Douglas-fir lignin: Importance of liquid-intermediate formation on the distribution of products

    NARCIS (Netherlands)

    Zhou, Shuai; Pecha, Brennan; van Kuppevelt, Michiel; McDonald, Armando G.; Garcia-Perez, Manuel

    2014-01-01

    The formation of liquid intermediates and the distribution of products were studied under slow and fast pyrolysis conditions. Results indicate that monomers are formed from lignin oligomeric products during secondary reactions, rather than directly from the native lignin. Lignin from Douglas-fir

  1. Seasonal carbohydrate dynamics and growth in Douglas-fir trees experiencing chronic, fungal-mediated reduction in functional leaf area

    Science.gov (United States)

    B. J. Saffell; F. C. Meinzer; D. R. Woodruff; D. C. Shaw; S. L. Voelker; B. Lachenbruch; K. Falk

    2014-01-01

    Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which NSCs can be mobilized...

  2. The influence of weather variation on regional growth of Douglas-fir stands in the U.S. Pacific Northwest.

    Science.gov (United States)

    Charles E. Peterson; Linda S. Heath

    1991-01-01

    In this paper we examine the influence of precipitation and temperature deviations on regional volume growth rates in even aged, onnen.,ed second growth Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) stands. Between 1969 and 1986, average volume growth rates in natural stands of coast Douglas fix in western Washington and Oregon were negatively...

  3. Symptoms associated with inoculation of stems on living Douglas-fir and Grand Fir Trees with Phytophthora ramorum

    Science.gov (United States)

    Gary Chastagner; Kathy Riley; Katie Coats; Marianne Elliott; Annie DeBauw; Norm Dart

    2010-01-01

    To obtain a better understanding of the potential risk of infection and colonization of living Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis) stems, the stems on over 150 trees of each species were inoculated at a Christmas tree farm near Los Gatos, California. This study had the following objectives: 1)...

  4. Genetic variation in tolerance of Douglas-fir to Swiss needle cast as assessed by symptom expression.

    Science.gov (United States)

    G.R. Jonhson

    2002-01-01

    The incidence of Swiss needle cast on Douglas-fir has increased significantly in recent years on the Oregon coast. Genetic variation in symptoms of disease infection, as measured by foliage traits, was assessed in two series of progeny trials to determine whether these "crown health" indicators were under genetic control and correlated with tolerance;...

  5. Estimation of population structure in coastal Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii] using allozyme and microsatellite markers

    Science.gov (United States)

    Konstantin V. Krutovsky; John Bradley St. Clair; Robert Saich; Valerie D. Hipkins; David B. Neale

    2009-01-01

    Characterizing population structure using neutral markers is an important first step in association genetic studies in order to avoid false associations between phenotypes and genotypes that may arise from nonselective demographic factors. Population structure was studied in a wide sample of approximately 1,300 coastal Douglas-fir [Pseudotsuga menziesii...

  6. Family differences in equations for predicting biomass and leaf area in Douglas-fir (Pseudotsuga menziesii var. menziesii).

    Science.gov (United States)

    J.B. St. Clair

    1993-01-01

    Logarithmic regression equations were developed to predict component biomass and leaf area for an 18-yr-old genetic test of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) based on stem diameter or cross-sectional sapwood area. Equations did not differ among open-pollinated families in slope, but intercepts...

  7. Two-dimensional heat flow analysis applied to heat sterilization of ponderosa pine and Douglas-fir square timbers

    Science.gov (United States)

    William T. Simpson

    2004-01-01

    Equations for a two-dimensional finite difference heat flow analysis were developed and applied to ponderosa pine and Douglas-fir square timbers to calculate the time required to heat the center of the squares to target temperature. The squares were solid piled, which made their surfaces inaccessible to the heating air, and thus surface temperatures failed to attain...

  8. Relationships among chilling hours, photoperiod, calendar date, cold hardiness, seed source, and storage of Douglas-fir seedlings

    Science.gov (United States)

    Diane L. Haase; Nabil Khadduri; Euan Mason; Kas Dumroese

    2016-01-01

    Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings from three nurseries in the Pacific Northwest United States were lifted on five dates from mid-October through mid-December 2006. Each nursery provided seedlings from a low- and a high-elevation seed lot. Photoperiod and accumulated chilling hours (calculated using two methods) were evaluated...

  9. Growth of Douglas-fir near equipment trails used for commercial thinning in the Oregon Coast Range.

    Science.gov (United States)

    Richard E. Miller; Jim Smith; Paul W. Adams; Harry W. Anderson

    2007-01-01

    Soil disturbance is a visually apparent result of using heavy equipment to harvest trees. Subsequent consequences for growth of remaining trees, however, are variable and seldom quantified. We measured tree growth 7 and 11 years after thinning of trees in four stands of coast Douglas-fir (Pseudotsuga menziesii var. menziesii(...

  10. Tree growth and soil relations at the 1925 Wind River spacing test in coast Douglas-fir.

    Science.gov (United States)

    Richard E. Miller; Donald L. Reukema; Harry W. Anderson

    2004-01-01

    The 1925 Wind River spacing test is the earliest field trial seeking to determine the most appropriate spacing for planting Douglas-fir. Spacing treatments were not replicated, although individual spacings were subsampled by two to four tree-measurement plots. Previously, greater growth occurred at the wider spacings (10 and 12 ft) than at the closer spacings (4, 5, 6...

  11. Detecting response of Douglas-fir plantations to urea fertilizer at three locations in the Oregon Coast Range.

    Science.gov (United States)

    Richard E. Miller; Jim Smith; Harry. Anderson

    2001-01-01

    Fertilizer trials in coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) in the Oregon Coast Range usually indicate small and statistically nonsignificant response to nitrogen (N) fertilizers. Inherently weak experimental designs of past trials could make them too insensitive to detect growth differences...

  12. Turbulence Considerations for Comparing Ecosystem Exchange over Old-Growth and Clear-Cut Stands For Limited Fetch and Complex Canopy Flow Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Schroeder, M; Paw U, K T; Falk, M; Bible, K

    2009-01-08

    Carbon dioxide, water vapor and energy fluxes were measured using eddy covariance (EC) methodology over three adjacent forests in southern Washington State to identify stand-level age-effects on ecosystem exchange. The sites represent Douglas-fir forest ecosystems at two contrasting successional stages: old-growth (OG) and early seral (ES). Here we present eddy flux and meteorological data from two early seral stands and the Wind River AmeriFlux old-growth forest during the growing season (March-October) in 2006 and 2007. We show an alternative approach to the usual friction velocity (u*) method for determining periods of adequate atmospheric boundary layer (ABL) mixing based on the ratio of mean horizontal ({bar u}) and vertical ({bar w}) wind flow to a modified turbulent kinetic energy scale (uTKE). This new parameter in addition to footprint modeling showed that daytime CO{sub 2} fluxes (F{sub NEE}) in small clear-cuts (< 10 hectares) can be measured accurately with EC if micrometeorological conditions are carefully evaluated. Peak midday CO{sub 2} fluxes (F{sub NEE} = -14.0 to -12.3 {micro}mol m{sup -2} s{sup -1}) at OG were measured in April in both 2006 and 2007 before bud break when air and soil temperatures and vapor pressure deficit were relatively low, and soil moisture and light levels were favorable for photosynthesis. At the early seral stands, peak midday CO{sub 2} fluxes (F{sub NEE} = -11.0 to -8.7 {micro}mol m{sup -2} s{sup -1}) were measured in June and July while spring-time CO{sub 2} fluxes were much smaller (F{sub NEE} = -3.8 to -3.6 {micro}mol m{sup -2} s{sup -1}). Overall, we measured lower evapotranspiration (OG = 230 mm; ES = 297 mm) higher midday F{sub NEE} (OG F{sub NEE} = -9.0 {micro}mol m{sup -2} s{sup -1}; ES F{sub NEE} = -7.3 {micro}mol m{sup -2} s{sup -1}) and higher Bowen ratios (OG {beta} = 2.0. ES {beta} = 1.2) at the old-growth forest than at the ES sites during the summer months (May-August). Eddy covariance studies such as ours

  13. Past, Present, and Future Old Growth in Frequent-fire Conifer Forests of the Western United States

    Directory of Open Access Journals (Sweden)

    Scott R. Abella

    2007-12-01

    Full Text Available Old growth in the frequent-fire conifer forests of the western United States, such as those containing ponderosa pine (Pinus ponderosa, Jeffrey pine (P. jeffreyi, giant sequoia (Sequioa giganteum and other species, has undergone major changes since Euro-American settlement. Understanding past changes and anticipating future changes under different potential management scenarios are fundamental to developing ecologically based fuel reduction or ecological restoration treatments. Some of the many changes that have occurred in these forests include shifts from historically frequent surface fire to no fire or to stand-replacing fire regimes, increases in tree density, increased abundance of fire-intolerant trees, decreases in understory productivity, hydrological alterations, and accelerated mortality of old trees. Although these changes are widespread, the magnitude and causes of changes may vary within and among landscapes. Agents of change, such as fire exclusion or livestock grazing, likely interacted and had multiple effects. For example, historical ranching operations may have altered both fire regimes and understory vegetation, and facilitated institutional fire exclusion through fragmentation and settlement. Evidence exists for large variation in presettlement characteristics and current condition of old growth across this broad forest region, although there are many examples of striking similarities on widely distant landscapes. Exotic species, climate change, unnatural stand-replacing wildfires, and other factors will likely continue to degrade or eradicate old growth in many areas. As a policy of fire exclusion is proving to be unsustainable, mechanical tree thinning, prescribed fire, or wildland fire use will likely be key options for forestalling continued eradication of old growth by severe crown fires. For many practical and societal reasons, the wildland-urban interface may afford some of the most immediate opportunities for re

  14. Understanding old-growth red and white pine dominated forests in Ontario. Forest fragmentation and biodiversity project technical report No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Carleton, T.J.; Gordon, A.M.

    1992-01-01

    In summer 1991, a variety of forest stands dominated by old specimens of white pine and red pine were sampled across a representative portion of the species' range in northcentral Ontario. Plots were established in 40 stands of those surveyed to identify the salient structural components of old-growth, to survey the floristic composition (vascular plants and autotrophic non- vascular plants), to survey site characteristics, and to estimate the links in understorey alpha diversity with site conditions and stand structure. Long-term objectives include a definition of old- growth pine forest, recognition criteria, and prospective management options. Forest stand structure was enumerated through mapping, mensurational, and age estimation techniques. Forest vegetation, including over and understorey species, was non- destructively sampled and a range of data on stand and soil-site variables was also collected in conjunction with information on stand variables peculiar to old growth forests.

  15. Elevated Annual Runoff Ratios in Pacific Northwest Catchments Impacted by Epidemic Foliage Disease of Douglas-fir

    Science.gov (United States)

    Bladon, K. D.; Bywater-Reyes, S.; LeBoldus, J. M.; Segura, C.; Ritokova, G.; Shaw, D. C.

    2017-12-01

    Catchments in the Western United States are undergoing unprecedented levels of tree die-off and/or reduced vigor due to increased severity of wildfire, drought, insect outbreaks, and disease. In the U.S. Pacific Northwest, Swiss needle cast (SNC) is the most damaging foliar disease of Douglas-fir (Pseudotsuga menziesii), physically obstructing stomata and preventing CO2 uptake and transpiration. A recent analysis in coastal Oregon indicated a substantial increase in area affected by the disease, from 530.5 km2 in 1996 to 2,387.1 km2 in 2015. Deforestation or reduced tree vigor can have profound impacts on catchment hydrology, in theory, producing increased streamflow due to reduced interception and transpiration. However, these increases have not always been detectable as impacts also depend on factors such as climate and vegetation composition. Moreover, press disturbances, such as insect outbreaks or disease, often do not result in complete removal of understorey or canopy vegetation. We analyzed trends in annual runoff ratios (quotient of discharge divided by precipitation) from 1990-2015 in 12 catchments (183-1,744 km2) in western Oregon. In general, runoff ratios increased by 10-27% in catchments with a total area of SNC >10%, with the most substantial runoff increases in catchments with SNC impacting >25% of the area. Interestingly, the most severely impacted catchment ( 90.5% SNC) showed a decrease in runoff. This is consistent with a potential compensatory response from understory western hemlock (Tsuga heterophylla) trees, a phenomenon observed in the most severely impacted sites. Findings from this study are important for assessing the impacts of biotic forest disturbances on water supply and aquatic ecosystem health.

  16. Distribution of bioluminescent fungi across old-growth and secondary tropical rain forest in Costa Rica

    Directory of Open Access Journals (Sweden)

    Carolina Seas-Carvajal

    2013-06-01

    Full Text Available Most research on bioluminescent fungi is concentrated on their taxonomic relationships, while the basics of their natural history and ecological relationships are poorly understood. In this study, we compared the distribution of bioluminescent fungi between old-growth and secondary forest as related to four different soil types at the tropical rainforest of La Selva Biological Station in Costa Rica. The study was conducted during the wet season of 2009. Bioluminescent fungi were sought following eight different transects distributed evenly in old-growth and secondary forests across four different soil types, covering an area of 9 420m². We found fungi in four different substrates: litter, fallen branches, dead trunks, and roots, for a total of 61 samples. Correspondence analysis showed that the occurrence of fungi and soil types were related (inertia=0.21, p=0.071. We found a significant relationship between the presence of fungi and the distribution of soil types (X²=18.89, df=9, p=0.026. We found only three samples with fruiting bodies, two of which had Mycena and the other had one fungus of the order Xylariales (possibly Hypoxylon sp., Kretzschmariella sp., Xylaria sp.. Future work will concentrate on exploring other aspects of their ecology, such as their dispersal and substrate preference. This information will facilitate field identification and will foster more research on the distribution, seasonality, reproductive phenology and ecological requirements of this group of Fungi.La mayoría de las investigaciones sobre los hongos bioluminiscentes se ha centrado en relaciones taxonómicas. Los aspectos básicos de la historia natural y relaciones ecológicas de este grupo son poco conocidos. En este estudio, comparamos la distribución de hongos bioluminiscentes entre el bosque primario y el secundario en la Estación Biológica La Selva, Costa Rica en relación con cuatro tipos de suelo. El estudio se realizó durante la estación lluviosa

  17. Age-related variation in genetic control of height growth in Douglas-fir.

    Science.gov (United States)

    Namkoong, G; Usanis, R A; Silen, R R

    1972-01-01

    The development of genetic variances in height growth of Douglas-fir over a 53-year period is analyzed and found to fall into three periods. In the juvenile period, variances in environmental error increase logarithmically, genetic variance within populations exists at moderate levels, and variance among populations is low but increasing. In the early reproductive period, the response to environmental sources of error variance is restricted, genetic variance within populations disappears, and populational differences strongly emerge but do not increase as expected. In the later period, environmental error again increases rapidly, but genetic variance within populations does not reappear and population differences are maintained at about the same level as established in the early reproductive period. The change between the juvenile and early reproductive periods is perhaps associated with the onset of ecological dominance and significant allocations of energy to reproduction.

  18. Dynamic anthropogenic edge effects on the distribution and diversity of fungi in fragmented old-growth forests.

    Science.gov (United States)

    Ruete, Alejandro; Snäll, Tord; Jönsson, Mari

    2016-07-01

    Diversity patterns and dynamics at forest edges are not well understood. We disentangle the relative importance of edge-effect variables on spatio-temporal patterns in species richness and occupancy of deadwood-dwelling fungi in fragmented old-growth forests. We related richness and log occupancy by 10 old-growth forest indicator fungi and by two common fungi to log conditions in natural and anthropogenic edge habitats of 31 old-growth Picea abies forest stands in central Sweden. We compared edge-to-interior gradients (100 m) to the forest interior (beyond 100 m), and we analyzed stand-level changes after 10 yr. Both richness and occupancy of logs by indicator species was negatively related to adjacent young clear-cut edges, but this effect decreased with increasing clear-cut age. The occupancy of logs by indicator species also increased with increasing distance to the natural edges. In contrast, the occupancy of logs by common species was positively related or unrelated to distance to clear-cut edges regardless of the edge age, and this was partly explained by fungal specificity to substrate quality. Stand-level mean richness and mean occupancy of logs did not change for indicator or common species over a decade. By illustrating the importance of spatial and temporal dimensions of edge effects, we extend the general understanding of the distribution and diversity of substrate-confined fungi in fragmented old-growth forests. Our results highlight the importance of longer forest rotation times adjacent to small protected areas and forest set-asides, where it may take more than 50 yr for indicator species richness levels to recover to occupancy levels observed in the forest interior. Also, non-simultaneous clear-cutting of surrounding productive forests in a way that reduces the edge effect over time (i.e., dynamic buffers) may increase the effective core area of small forest set-asides and improve their performance on protecting species of special concern for

  19. Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range

    Science.gov (United States)

    Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen to increase growth rates. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The objective ...

  20. Long-term changes in tree composition in a mesic old-growth upland forest in southern Illinois

    Science.gov (United States)

    James J. Zaczek; John W. Groninger; J.W. Van Sambeek

    1999-01-01

    The Kaskaskia Woods (Lat. 37.5 N, Long. 88.3 W), an old-growth hardwood forest in southern Illinois, has one of the oldest and best documented set of permanent plots with individual tree measurements in the Central Hardwood Region. In 1935, eight 0.101-ha plots were installed in a 7.4 ha upland area consisting of xeric oak-hickory and mesic mixed hardwoods communities...

  1. Abundance and Size Distribution of Cavity Trees in Second-Growth and Old-Growth Central Hardwood Forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson III; David R. Larsen

    2005-01-01

    In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

  2. Abundance and size distribution of cavity trees in second-growth and old-growth central hardwood forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson; David R. Larsen

    2005-01-01

    In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

  3. Protecting rare, old-growth, forest-associated species under the Survey and Manage program guidelines of the northwest forest plan.

    Science.gov (United States)

    Randy Molina; Bruce G. Marcot; Robin. Lesher

    2006-01-01

    The Survey and Manage Program of the Northwest Forest Plan (MFP) represents an unparalleled attempt to protect rare, little-known species associated with late-successional and old-growth forests on more than 7.7 million ha of federal lands. Approximately 400 species of amphibians, bryophytes, fungi, lichens, mollusks, vascular plants, arthropod functional groups, and...

  4. Longevity of Wood-Forced Pools in an Old-Growth Forest

    Science.gov (United States)

    Buffington, J. M.; Woodsmith, R. D.; Johnson, A. C.

    2009-12-01

    Wood debris plays an important role in scouring pools in forest channels and providing resultant habitat for aquatic organisms. We investigated the longevity of such pools in a gravel-bed river flowing through old-growth forest in southeastern Alaska by aging trees and “bear’s bread” fungi (Ganoderma applanatum, Fomitopsis pinicola) growing on pool-forming wood debris. Ages were determined by counting annual growth rings from cores and cross sections of trees and fungi growing on the wood debris. These ages are minimum values because they do not account for lag time between debris recruitment and seedling/spore establishment on the debris, nor do they account for flood scour that may periodically reset tree and fungi growth on the debris. The study stream has a gradient of about 1%, bankfull width and depth of 13.3 and 0.78 m, respectively, median grain size of 18 mm, a high wood loading (0.8 pieces/m), and a correspondingly low pool spacing (0.3 bankfull widths/pool), with 81% of the pools forced by wood debris. The size of wood debris in the study stream is large relative to the channel (average log length of 7.6 m and diameter of 0.35 m), rendering most debris immobile. Eighty-one pool-forming pieces of wood were dated over 1.2 km of stream length, with 28% of these pieces causing scour of more than one pool. In all, 122 wood-forced pools were dated, accounting for 38% of all pools at the site and 47% of the wood-forced pools. Fifty-three percent of the wood-forced pools lacked datable wood because these pieces either: were newly recruited; had been scoured by floods; or were contained below the active channel elevation, prohibiting vegetation establishment on the wood debris (the most common cause). The debris age distribution declined exponentially from 2 to 113 yrs., with a median value of 18 yrs. Similar exponential residence time distributions have been reported in other studies, but our analysis focused specifically on the ages of pool-forming wood

  5. Spider (Arachnida, Araneae) diversity in secondary and old-growth southern Atlantic forests of Paraná state, Brazil.

    Science.gov (United States)

    Raub, Florian; Höfer, Hubert; Scheuermann, Ludger

    2017-07-01

    The data presented here have been collected in the southern part of the Atlantic Forest (Mata Atlântica) in the state of Paraná, Brazil within a bilateral scientific project (SOLOBIOMA). The project aimed to assess the quality of secondary forests of different regeneration stages in comparison with old-growth forests with regard to diversity of soil animals and related functions. The Atlantic Forest is a hotspot of biological diversity with an exceptionally high degree of endemic species, extending over a range of 3,500 km along the coast of Brazil. The anthropogenic pressure in the region is very high with three of the biggest cities of Brazil (São Paulo, Rio de Janeiro, and Curitiba) lying in its extension. An evaluation of the value of secondary forests for biodiversity conservation is becoming more and more important due to the complete disappearance of primary forests. In 2005, we sampled spiders in 12 sites of three successional stages (5-8, 10-15, 35-50 yr old, three replicates of each forest stage) and old-growth forests (> 100 yr untouched, also three replicates). All sites were inside a private nature reserve (Rio Cachoeira Nature Reserve). We repeated the sampling design and procedure in 2007 in a second private reserve (Itaqui Nature Reserve). The two nature reserves are within about 25 km of each other within a well preserved region of the Mata Atlântica, where the matrix of the landscape mosaic is still forest. A widely accepted standard protocol was used in a replicated sampling design to apply statistical analyses to the resulting data set and allow for comparison with other studies in Brazil. Spiders were sorted to family level and counted; the adult spiders further identified to species if possible or classified as morphospecies with the help of several spider specialists. © 2017 by the Ecological Society of America.

  6. Effects of long-term pruning, meristem origin, and branch order on the rooting of Douglas-fir stem cuttings.

    Science.gov (United States)

    D.L. Copes

    1992-01-01

    The rooting percentages of 14 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) clones were examined annually from 1974 to 1988. The trees were 10 and 13 years old in 1974 and were pruned to 2.0 m in 1978 and 1979 and then recut annually to 0.5, 1.0, or 1.5 m, starting in 1983. The pruned trees showed no evidence of decreased rooting percentage...

  7. Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles

    OpenAIRE

    Cronn, Richard; Dolan, Peter C.; Jogdeo, Sanjuro; Wegrzyn, Jill L.; Neale, David B.; St. Clair, J. Bradley; Denver, Dee R.

    2017-01-01

    Background Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) n...

  8. Transcription Through The Eye Of A Needle: Daily And Annual Cycles Of Gene Expression Variation In Douglas-Fir Needles

    OpenAIRE

    Dolan, Peter; Cronn, Richard; Denver, Dee; Clair, J.; Neale, David; Wegrzyn, Jill; Jogdeo, Sanjuro

    2017-01-01

    Background: Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal rhythms and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii)...

  9. Characteristics and dynamics of an upland Missouri old-growth forest

    Science.gov (United States)

    R. Hoyt Richards; Stephen R. Shifley; Alan J. Rebertus; Stephen J. Chaplin

    1995-01-01

    We describe the structure, composition, and dynamics of Schnabel Woods, an 80-acre mixed mesophytic old-growth stand located in the loess-covered River Hills adjoining the Missouri River floodplain in central Missouri. In 1982 all trees on a 1.5-ac northwest-facing plot and a 1.5-ac southeast-facing plot were mapped and measured. In 1992 we remeasured those plots to...

  10. Tractor-logging costs and production in old-growth redwood forests

    Science.gov (United States)

    Kenneth N. Boe

    1963-01-01

    A cost accounting analysis of full-scale logging operations in old-growth redwood during 2 years revealed that it cost $12.24 per M bd. ft. (gross Scribner log scale) to get logs on trucks. Road development costs averaged another $5.19 per M bd. ft. Felling-bucking production was calculated by average tree d.b.h. Both skidding and loading outputs per hour were...

  11. Tree growth and competition in an old-growth Picea abies forest of boreal Sweden: influence of tree spatial patterning

    Science.gov (United States)

    Fraver, Shawn; D'Amato, Anthony W.; Bradford, John B.; Jonsson, Bengt Gunnar; Jönsson, Mari; Esseen, Per-Anders

    2013-01-01

    Question: What factors best characterize tree competitive environments in this structurally diverse old-growth forest, and do these factors vary spatially within and among stands? Location: Old-growth Picea abies forest of boreal Sweden. Methods: Using long-term, mapped permanent plot data augmented with dendrochronological analyses, we evaluated the effect of neighbourhood competition on focal tree growth by means of standard competition indices, each modified to include various metrics of trees size, neighbour mortality weighting (for neighbours that died during the inventory period), and within-neighbourhood tree clustering. Candidate models were evaluated using mixed-model linear regression analyses, with mean basal area increment as the response variable. We then analysed stand-level spatial patterns of competition indices and growth rates (via kriging) to determine if the relationship between these patterns could further elucidate factors influencing tree growth. Results: Inter-tree competition clearly affected growth rates, with crown volume being the size metric most strongly influencing the neighbourhood competitive environment. Including neighbour tree mortality weightings in models only slightly improved descriptions of competitive interactions. Although the within-neighbourhood clustering index did not improve model predictions, competition intensity was influenced by the underlying stand-level tree spatial arrangement: stand-level clustering locally intensified competition and reduced tree growth, whereas in the absence of such clustering, inter-tree competition played a lesser role in constraining tree growth. Conclusions: Our findings demonstrate that competition continues to influence forest processes and structures in an old-growth system that has not experienced major disturbances for at least two centuries. The finding that the underlying tree spatial pattern influenced the competitive environment suggests caution in interpreting traditional tree

  12. Forty-two years of change in an old-growth and second-growth beech-maple forest of north central Ohio

    Science.gov (United States)

    Natalie R. Pinheiro; P. Charles Goebel; David M. Hix

    2008-01-01

    Using data collected in 1964 and 2006, we examined changes in the composition and structure of a second-growth and old-growth beech-maple forest of Crall Woods, located in Ashland County of north central Ohio. Over the 42 years, the old-growth forest (estimated to be at least 250 years old) experienced a significant shift in species composition as American beech,...

  13. The steady-state mosaic of disturbance and succession across an old-growth Central Amazon forest landscape.

    Science.gov (United States)

    Chambers, Jeffrey Q; Negron-Juarez, Robinson I; Marra, Daniel Magnabosco; Di Vittorio, Alan; Tews, Joerg; Roberts, Dar; Ribeiro, Gabriel H P M; Trumbore, Susan E; Higuchi, Niro

    2013-03-05

    Old-growth forest ecosystems comprise a mosaic of patches in different successional stages, with the fraction of the landscape in any particular state relatively constant over large temporal and spatial scales. The size distribution and return frequency of disturbance events, and subsequent recovery processes, determine to a large extent the spatial scale over which this old-growth steady state develops. Here, we characterize this mosaic for a Central Amazon forest by integrating field plot data, remote sensing disturbance probability distribution functions, and individual-based simulation modeling. Results demonstrate that a steady state of patches of varying successional age occurs over a relatively large spatial scale, with important implications for detecting temporal trends on plots that sample a small fraction of the landscape. Long highly significant stochastic runs averaging 1.0 Mg biomass⋅ha(-1)⋅y(-1) were often punctuated by episodic disturbance events, resulting in a sawtooth time series of hectare-scale tree biomass. To maximize the detection of temporal trends for this Central Amazon site (e.g., driven by CO2 fertilization), plots larger than 10 ha would provide the greatest sensitivity. A model-based analysis of fractional mortality across all gap sizes demonstrated that 9.1-16.9% of tree mortality was missing from plot-based approaches, underscoring the need to combine plot and remote-sensing methods for estimating net landscape carbon balance. Old-growth tropical forests can exhibit complex large-scale structure driven by disturbance and recovery cycles, with ecosystem and community attributes of hectare-scale plots exhibiting continuous dynamic departures from a steady-state condition.

  14. Spatially nonrandom tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga-Tsuga forest.

    Science.gov (United States)

    Lutz, James A; Larson, Andrew J; Furniss, Tucker J; Donato, Daniel C; Freund, James A; Swanson, Mark E; Bible, Kenneth J; Chen, Jiquan; Franklin, Jerry F

    2014-08-01

    Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga-Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant late-successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii experienced an annual stem mortality rate of 0.84% and no new recruitment. Late-seral species Tsuga and Abies amabilis had nearly balanced demographic rates of ingrowth and mortality. The 2.34% mortality rate for Taxus brevifolia was higher than expected, notably less than ingrowth, and strongly affected by proximity to Tsuga. Large-diameter Tsuga structured both the regenerating conspecific and heterospecific cohorts with recruitment of Tsuga and Abies unlikely in neighborhoods crowded with large-diameter competitors (P old-growth forests.

  15. The Effect of Herbivory by White-Tailed Deer and Additionally Swamp Rabbits in an Old-Growth Bottomland Hardwood Forest

    Science.gov (United States)

    Margaret S. Devall; Bernard R. Parresol; Winston P. Smith

    2001-01-01

    Forest openings create internal patchiness and offer different habitat qualities that attract wildlife, especially herbivores, that flourish along forest edges. But intense herbivory in these openings can reduce or eliminate herbaceous and woody species and thus influence local species composition and structure of the forest. This study in an old-growth bottomland...

  16. Wood Anatomy and Insect Defoliator Systems: Is there an anatomical response to sustained feeding by the western spruce budworm (Choristoneura occidentalis) on Douglas-fir (Pseudotusga menziesii)?

    Science.gov (United States)

    Axelson, Jodi; Gärtner, Holger; Alfaro, René; Smith, Dan

    2013-04-01

    The western spruce budworm (Choristoneura occidentalis Freeman) is the most widespread and destructive defoliator of coniferous forests in western North America, and has a long-term coexistence with its primary host tree, Douglas-fir (Pseudotsuga menziesii Franco). Western spruce budworm (WSB) outbreaks usually last for several years, and cause reductions in annual growth, stem defects, and regeneration delays. In British Columbia, the WSB is the second most damaging insect after the mountain pine beetle, and sustained and/or severe defoliation can result in the mortality of host trees. Numerous studies have used tree rings to reconstruct WSB outbreaks across long temporal scales, to evaluate losses in stand productivity, and examine isotope ratios. Although some studies have looked at the impacts of artificial defoliation on balsam fir in eastern North America, there has been no prior research on how WSB outbreaks affect the anatomical structure of the stem as described by intra-annual wood density and potential cell size variations. The objective of this study was to anatomically examine the response of Douglas-fir to sustained WSB outbreaks in two regions of southern British Columbia. We hypothesize that the anatomical intra-annual characteristics of the tree rings, such as cell wall thickness, latewood cell size, and/or lumen area changes during sustained WSB outbreaks. To test this hypothesis we sampled four permanent sample plots in coastal and dry interior sites, which had annually resolved defoliation data collected over a 7-12 year period. At each site diameter-at-breast height (cm), height (m), and crown position were recorded and three increment cores were extracted from 25 trees. Increment cores were prepared to permit anatomical and x-ray density analyses. For each tree, a 15µm thick micro section was cut from the radial plane. Digital images of the micro sections were captured and processed. In each annual ring, features such as cell lumen area (µm2

  17. Living and Dead Aboveground Biomass in Mediterranean Forests: Evidence of Old-Growth Traits in a Quercus pubescens Willd. s.l. Stand

    Directory of Open Access Journals (Sweden)

    Emilio Badalamenti

    2017-05-01

    Full Text Available For a long time, human impact has deeply simplified most of the forest ecosystems of the Mediterranean Basin. Here, forests have seldom had the chance to naturally develop a complex and multilayered structure, to host large and old trees and rich biological communities, approaching old-growth conditions. Also for this reason, limited information is currently available about Mediterranean old-growth forests, particularly with regard to deadwood. The main aim of this work is to help fill this critical knowledge gap. In Sicily (Italy, we identified a Quercus pubescens forest that seemed to show some typical old-growth features. Total living volume (360 m3 ha−1 and basal area (34 m2 ha−1 were, respectively, about 6 and 3 times higher than the averages recorded in the regional forest inventory for this forest type. Deadwood was particularly abundant, exceeding the threshold of 30 m3 ha−1, mainly represented by lying dead elements. Dead to live wood ratio reached 9%, a value close to the threshold of 10% considered for Mediterranean old-growth forests. As the investigated forest showed some typical old-growth traits, it deserves to be fully protected and could be a permanent monitoring area for studying deadwood and stand dynamics in mature Mediterranean stands.

  18. Monitoring soil chemical and physical parameters under Douglas fir in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Konsten, C.J.M.; Tiktak, A.; Bouten, W.

    1987-01-01

    In march 1987 a monitoring program started in two Douglas fir stands of different vitality in the Netherlands. Aim of the study is to provide insight in the chemical and physical rooting conditions of the vegetation and to quantify the contributions of atmospheric deposition to soil acidification. The hydrological part of the monitoring progam consists of automated measurements of precipitation, throughfall, soil water pressure head and soil water content; in addition soil water content is determined by neutron sonde measurements and gravimetry. These data are used as input data for simulation models which calculate water fluxes through the vegetation and soil. For the soil chemical part of the program precipitation (bulk and wet-only), throughfall and litter fall are sampled. The soil solution is sampled by suction from porous cups and from porous plates by a new, continous technique. Combination of soil chemical and soil physical data will result in chemical fluxes through the vegetation and through various soil compartments. Element budgets for the ecosystem will also be calculated. The program forms part of an interdisciplinary monitoring project within the Dutch Priority Programme on Acidification. 2 figs., 1 tab., 19 refs.

  19. Rapid structural and compositional change in an old-growth subtropical forest: using plant traits to identify probable drivers.

    Science.gov (United States)

    Malizia, Agustina; Easdale, Tomás A; Grau, H Ricardo

    2013-01-01

    Recent studies have shown directional changes in old-growth tropical forests, but changes are complex and diverse, and their drivers unclear. Here, we report rapid net structural and compositional changes in an old-growth subtropical forest and we assess the functional nature of these changes to test hypothetical drivers including recovery from past disturbances, reduction in ungulate browsing, CO2 fertilization, and increases in rainfall and temperature. The study relies on 15 years of demographic monitoring within 8 ha of subtropical montane forest in Argentina. Between 1992 and 2007, stem density markedly increased by 50% (12 stems ha(-1) y(-1)) and basal area by 6% (0.13 m(2) ha(-1) y(-1)). Increased stem density resulted from enhanced recruitment of understory treelets (Piper tucumanum, Eugenia uniflora, Allophylus edulis) into small size classes. Among 27 common tree species, net population growth was negatively correlated with maximum tree size and longevity, and positively correlated with leaf size and leaf nutrient content, especially so when initial population size was controlled for. Changes were inconsistent with predictions derived from past disturbances (no increase in shade-tolerant or long-lived late-succesional species), rainfall or temperature increase (no increase in evergreen or deciduous species, respectively). However, the increase in nutrient-rich soft-leaved species was consistent with exclusion of large herbivores two decades before monitoring started; and CO2 fertilization could help explain the disproportionate increase in small stems. Reductions in populations of large vertebrates have been observed in many otherwise undisturbed tropical forests, and our results suggest they can have important structural and functional repercussions in these forests.

  20. Simulation of Landscape Pattern of Old Growth Forests of Korean Pine by Block Kringing

    Science.gov (United States)

    Wang Zhengquan; Wang Qingcheng; Zhang Yandong

    1997-01-01

    The study area was located in Liangshui Natural Reserve. Xaozing'an Mountains, Northeastern China. Korean pine forests are the typical forest ecosystems and landscapes in this region. It is a high degress of spatial and temporal heterogeneity at different scales, which effected on landscape pattern and processes. In this paper we used the data of 144 plots and...

  1. Old-growth Policy

    Directory of Open Access Journals (Sweden)

    Diane Vosick

    2007-12-01

    Full Text Available Most federal legislation and policies (e.g., the Wilderness Act, Endangered Species Act, National Forest Management Act fail to speak directly to the need for old-growth protection, recruitment, and restoration on federal lands. Various policy and attitudinal barriers must be changed to move beyond the current situation. For example, in order to achieve the goal of healthy old growth in frequent-fire forests, the public must be educated regarding the evolutionary nature of these ecosystems and persuaded that collaborative action rather than preservation and litigation is the best course for the future of these forests. Land managers and policy makers must be encouraged to look beyond the single-species management paradigm toward managing natural processes, such as fire, so that ecosystems fall within the natural range of variability. They must also see that, given their recent evidence of catastrophic fires, management must take place outside the wildland-urban interface in order to protect old-growth forest attributes and human infrastructure. This means that, in some wilderness areas, management may be required. Land managers, researchers, and policy makers will also have to agree on a definition of old growth in frequent-fire landscapes; simply adopting a definition from the mesic Pacific Northwest will not work. Moreover, the culture within the federal agencies needs revamping to allow for more innovation, especially in terms of tree thinning and wildland fire use. Funding for comprehensive restoration treatments needs to be increased, and monitoring of the Healthy Forest Initiative and Healthy Forest Restoration Act must be undertaken.

  2. Drought effects on root and needle terpenoid content of a coastal and an interior Douglas fir provenance.

    Science.gov (United States)

    Kleiber, Anita; Duan, Qiuxiao; Jansen, Kirstin; Verena Junker, Laura; Kammerer, Bernd; Rennenberg, Heinz; Ensminger, Ingo; Gessler, Arthur; Kreuzwieser, Jürgen

    2017-12-01

    Douglas fir (Pseudotsuga menziesii) is a conifer species that stores large amounts of terpenoids, mainly monoterpenoids in resin ducts of various tissues. The effects of drought on stored leaf terpenoid concentrations in trees are scarcely studied and published data are partially controversial, since reduced, unaffected or elevated terpenoid contents due to drought have been reported. Even less is known on the effect of drought on root terpenoids. In the present work, we investigated the effect of reduced water availability on the terpenoid content in roots and needles of Douglas fir seedlings. Two contrasting Douglas fir provenances were studied: an interior provenance (var. glauca) with assumed higher drought resistance, and a coastal provenance (var. menziesii) with assumed lower drought resistance. We tested the hypothesis that both provenances show specific patterns of stored terpenoids and that the patterns will change in response to drought in both, needles and roots. We further expected stronger changes in the less drought tolerant coastal provenance. For this purpose, we performed an experiment under controlled conditions, in which the trees were exposed to moderate and severe drought stress. According to our expectations, the study revealed clear provenance-specific terpenoid patterns in needles. However, such patterns were not detected in the roots. Drought slightly increased the needle terpenoid contents of the coastal but not of the interior provenance. We also observed increased terpenoid abundance mainly in roots of the moderately stressed coastal provenance. Overall, from the observed provenance-specific reactions with increased terpenoid levels in trees of the coastal origin in response to drought, we conclude on functions of terpenoids for abiotic stress tolerance that might be fulfilled by other, constitutively expressed mechanisms in drought-adapted interior provenances. © The Author 2017. Published by Oxford University Press. All rights

  3. Species distribution models may misdirect assisted migration: insights from the introduction of Douglas-fir to Europe.

    Science.gov (United States)

    Boiffin, Juliette; Badeau, Vincent; Bréda, Nathalie

    2017-03-01

    Species distribution models (SDMs), which statistically relate species occurrence to climatic variables, are widely used to identify areas suitable for species growth under future climates and to plan for assisted migration. When SDMs are projected across times or spaces, it is assumed that species climatic requirements remain constant. However, empirical evidence supporting this assumption is rare, and SDM predictions could be biased. Historical human-aided movements of tree species can shed light on the reliability of SDM predictions in planning for assisted migration. We used Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a North American conifer introduced into Europe during the mid-19th century, as a case-study to test niche conservatism. We combined transcontinental data sets of Douglas-fir occurrence and climatic predictors to compare the realized niches between native and introduced ranges. We calibrated a SDM in the native range and compared areas predicted to be climatically suitable with observed presences. The realized niches in the native and introduced ranges showed very limited overlap. The SDM calibrated in North America had very high predictive power in the native range, but failed to predict climatic suitability in Europe where Douglas-fir grows in climates that have no analogue in the native range. We review the ecological mechanisms and silvicultural practices that can trigger such shifts in realized niches. Retrospective analysis of tree species introduction revealed that the assumption of niche conservatism is erroneous. As a result, distributions predicted by SDM are importantly biased. There is a high risk that assisted migration programs may be misdirected and target inadequate species or introduction zones. © 2016 by the Ecological Society of America.

  4. The limited contribution of large trees to annual biomass production in an old-growth tropical forest.

    Science.gov (United States)

    Ligot, Gauthier; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis-Yaoba; Morin, Xavier; Bauwens, Sébastien; Baya, Fidele; Brostaux, Yves; Doucet, Jean-Louis; Fayolle, Adeline

    2018-04-16

    Although the importance of large trees regarding biodiversity and carbon stock in old-growth forests is undeniable, their annual contribution to biomass production and carbon uptake remains poorly studied at the stand level. To clarify the role of large trees in biomass production, we used data of tree growth, mortality, and recruitment monitored during 20 yr in 10 4-ha plots in a species-rich tropical forest (Central African Republic). Using a random block design, three different silvicultural treatments, control, logged, and logged + thinned, were applied in the 10 plots. Annual biomass gains and losses were analyzed in relation to the relative biomass abundance of large trees and by tree size classes using a spatial bootstrap procedure. Although large trees had high individual growth rates and constituted a substantial amount of biomass, stand-level biomass production decreased with the abundance of large trees in all treatments and plots. The contribution of large trees to annual stand-level biomass production appeared limited in comparison to that of small trees. This pattern did not only originate from differences in abundance of small vs. large trees or differences in initial biomass stocks among tree size classes, but also from a reduced relative growth rate of large trees and a relatively constant mortality rate among tree size classes. In a context in which large trees are increasingly gaining attention as being a valuable and a key structural characteristic of natural forests, the present study brought key insights to better gauge the relatively limited role of large trees in annual stand-level biomass production. In terms of carbon uptake, these results suggest, as already demonstrated, a low net carbon uptake of old-growth forests in comparison to that of logged forests. Tropical forests that reach a successional stage with relatively high density of large trees progressively cease to be carbon sinks as large trees contribute sparsely or even

  5. Carbon stocks and greenhouse gas balance of an old-growth forest and an anthropogenic peatland in southern Chile

    Science.gov (United States)

    Perez-Quezada, J. F.; Brito, C. E.; Valdés, A.; Urrutia, P.

    2016-12-01

    Few studies have reported the effects of deforestation on carbon stocks and greenhouse gas balance in the temperate forests of the southern hemisphere. In some areas of southern Chile, after clear-cut or forest fires occurs a proliferation of Sphagnum moss, generating an anthropogenic type of peatland. We measured the effects of this change on the carbon stocks and the greenhouse gas balance, starting in 2013. Carbon stocks were measured in >30 plots on each site; ecosystem CO2 fluxes were measured continuously using eddy covariance stations; CH4 and N2O fluxes were measured monthly using closed chambers and cavity ring-down spectroscopy technology. Total ecosystem carbon stock was 1,523 Mg ha-1 in the forest and 130 Mg ha-1 in the peatland, representing a 91% difference. Both land use types were found to act as sinks of CO2 (NEE=-1094.2 and -31.9 g CO2 m-2 year-¹ for the forest and peatland, respectively); CH4 was mainly captured in the forest and peatland soils, generating balances of -0.70 and -0.12 g CH₄ m-2 year-¹. N2O fluxes were extremely low, so were considered as null. These results indicate that the greenhouse gas balance moved from -1134.6 to -38.8 g CO2-eq m-2 year-1 when land use changed from forest to anthropogenic peatland. These results provide evidence of the importance of preserving old-growth forests in southern Chile.

  6. Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests.

    Science.gov (United States)

    Fry, Danny L; Stephens, Scott L; Collins, Brandon M; North, Malcolm P; Franco-Vizcaíno, Ernesto; Gill, Samantha J

    2014-01-01

    In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha(-1), and occupied 27-46% of the study areas. Average canopy gap sizes (0.04 ha) covering 11-20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥ 56%) in large patches (≥ 10 trees), and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types.

  7. Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests.

    Directory of Open Access Journals (Sweden)

    Danny L Fry

    Full Text Available In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha(-1, and occupied 27-46% of the study areas. Average canopy gap sizes (0.04 ha covering 11-20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥ 56% in large patches (≥ 10 trees, and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types.

  8. Identifying conservation and restoration priorities for saproxylic and old-growth forest species: a case study in Switzerland.

    Science.gov (United States)

    Lachat, Thibault; Bütler, Rita

    2009-07-01

    Saproxylic (dead-wood-associated) and old-growth species are among the most threatened species in European forest ecosystems, as they are susceptible to intensive forest management. Identifying areas with particular relevant features of biodiversity is of prime concern when developing species conservation and habitat restoration strategies and in optimizing resource investments. We present an approach to identify regional conservation and restoration priorities even if knowledge on species distribution is weak, such as for saproxylic and old-growth species in Switzerland. Habitat suitability maps were modeled for an expert-based selection of 55 focal species, using an ecological niche factor analyses (ENFA). All the maps were then overlaid, in order to identify potential species' hotspots for different species groups of the 55 focal species (e.g., birds, fungi, red-listed species). We found that hotspots for various species groups did not correspond. Our results indicate that an approach based on "richness hotspots" may fail to conserve specific species groups. We hence recommend defining a biodiversity conservation strategy prior to implementing conservation/restoration efforts in specific regions. The conservation priority setting of the five biogeographical regions in Switzerland, however, did not differ when different hotspot definitions were applied. This observation emphasizes that the chosen method is robust. Since the ENFA needs only presence data, this species prediction method seems to be useful for any situation where the species distribution is poorly known and/or absence data are lacking. In order to identify priorities for either conservation or restoration efforts, we recommend a method based on presence data only, because absence data may reflect factors unrelated to species presence.

  9. Site quality influence over understory plant diversity in old-growth and harvested Nothofagus pumilio forests

    Directory of Open Access Journals (Sweden)

    E. A. Gallo

    2013-04-01

    Full Text Available Aim of study: The effects and interactions of shelterwood forest harvesting and site qualities over understory plant species diversity and composition were compared among primary and harvested Nothofagus pumilio forests.Area of study: Tierra del Fuego (Argentina, on three pure conditions (one and six year-old harvested, and primary without previous harvesting forests and three site qualities (high, medium and low.Material and Methods: Understory richness and cover (% were registered in five replicates of 1 hectare each per treatment. Taxonomic species were classified in categories (groups, origin and life forms. Two-way ANOVAs and multivariate analyses were conducted.Main results: Shelterwood harvesting and site quality significantly influenced understory cover and richness, which allow the introduction of native and exotic species and increasing of dicot and monocot covers. In dicots, monocots, exotics and total groups, higher richness and covers were related to time. Meanwhile, cover reached similar high values in all site qualities on dicot, native and total groups. On the other hand, monocot and exotic richness and cover remain similar in primary and recently harvested forests, and greatly increased in old harvested forests. Mosses and ferns were among the most sensitive groups.Research highlights: Impacts of shelterwood cut depend on site quality of the stands and time since harvesting occurs. For this, different site quality stands should received differential attention in the development of conservation strategies, as well as variations in the shelterwood implementation (as irregularity and patchiness should be considered to better promote understory plant species conservation inside managed areas.Key words: plant species conservation; years after harvesting; forest management; Tierra del Fuego.

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

    Directory of Open Access Journals (Sweden)

    Enqing Hou

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

  11. Long-term mortality rates and spatial patterns in an old-growth forest

    Science.gov (United States)

    Emily J. Silver; Shawn Fraver; Anthony W. D' Amato; Tuomas Aakala; Brian J. Palik

    2013-01-01

    Understanding natural mortality patterns and processes of forest tree species is increasingly important given projected changes in mortality owing to global change. With this need in mind, the rate and spatial pattern of mortality was assessed over an 89-year period in a natural-origin Pinus resinosa (Aiton)-dominated system to assess these processes...

  12. Storm intensity and old-growth forest disturbances in the Amazon region

    Science.gov (United States)

    F.D.B. Espírito-Santo; M. Keller; B. Braswell; B.W. Nelson; S. Frolking; G. Vicente

    2010-01-01

    We analyzed the pattern of large forest disturbances or blow‐downs apparently caused by severe storms in a mostly unmanaged portion of the Brazilian Amazon using 27 Landsat images and daily precipitation estimates from NOAA satellite data. For each Landsat a spectral mixture analysis (SMA) was applied. Based on SMA, we detected and mapped 279 patches (from 5 ha to 2,...

  13. Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA

    Directory of Open Access Journals (Sweden)

    Kerry D. Woods

    2014-09-01

    Full Text Available Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962–2009, combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360–450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study. Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis.CWD pools measured in 2007 averaged 151 m3/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated; snags constituted 10–50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9–3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer

  14. Effects of mountain beaver management and thinning on 15-year-old Douglas fir growth and survival.

    Science.gov (United States)

    Campbell, Dan L; Engeman, Richard M; Farley, James P

    2015-07-01

    We examined 4-year growth of 15-year-old damaged and undamaged Douglas fir (Pseudotsuga menzesii) after integrating temporary population reductions of mountain beaver (Aplodontia rufa) with thinning in a pre-commercial hand-planted plantation in western Washington. Five treatment combinations were considered: (1) trapping mountain beavers in an unthinned area, (2) trapping before thinning to 65 trees/ha (160 trees/ac), (3) no trapping and thinning to 65 trees/ha, (4) no trapping and thinning to 146 trees/ha (360 trees/ac), and (5) no trapping and no thinning. Removal of ≥ 90 % of mountain beavers temporarily reduced mountain beaver activity whether the stand was unthinned or thinned. Diameter growth at breast height (dbh) was greater for undamaged trees than for damaged trees in thinned areas. Tree height growth was greatest in trapped areas whether thinned or not. No differences were detected in 4-year survival between trees damaged aboveground and those without aboveground damage, which may be related to undetected root damage to trees without aboveground damage. Basal diameter growth and dbh growth were greatest for areas thinned to 65 trees/ha. Seventy-eight percent of stomachs from mountain beaver trapped in winter contained Douglas fir root or stem materials. Overall, short-term removal of mountain beavers integrated with pre-commercial thinning promoted growth of crop trees.

  15. Seasonal carbohydrate dynamics and growth in Douglas-fir trees experiencing chronic, fungal-mediated reduction in functional leaf area.

    Science.gov (United States)

    Saffell, Brandy J; Meinzer, Frederick C; Woodruff, David R; Shaw, David C; Voelker, Steven L; Lachenbruch, Barbara; Falk, Kristen

    2014-03-01

    Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which NSCs can be mobilized under natural conditions of low water stress and restricted carbon supply in relation to potential demands for growth. We analyzed the concentrations of starch, sucrose, glucose and fructose in foliage, twig wood and trunk sapwood of 15 co-occurring Douglas-fir trees expressing a gradient of Swiss needle cast symptom severity quantified as previous-year functional foliage mass. Growth (mean basal area increment, BAI) decreased by ∼80% and trunk NSC concentration decreased by 60% with decreasing functional foliage mass. The ratio of relative changes in NSC concentration and BAI, an index of the relative priority of storage versus growth, more than doubled with increasing disease severity. In contrast, twig and foliage NSC concentrations remained nearly constant with decreasing functional foliage mass. These results suggest that under disease-induced reductions in carbon supply, Douglas-fir trees retain NSCs (either actively or due to sequestration) at the expense of trunk radial growth. The crown retains the highest concentrations of NSC, presumably to maintain foliage growth and shoot extension in the spring, partially compensating for rapid foliage loss in the summer and fall.

  16. Spatial characteristics of tree diameter distributions in a temperate old-growth forest.

    Science.gov (United States)

    Zhang, Chunyu; Wei, Yanbo; Zhao, Xiuhai; von Gadow, Klaus

    2013-01-01

    This contribution identifies spatial characteristics of tree diameter in a temperate forest in north-eastern China, based on a fully censused observational study area covering 500×600 m. Mark correlation analysis with three null hypothesis models was used to determine departure from expectations at different neighborhood distances. Tree positions are clumped at all investigated scales in all 37 studied species, while the diameters of most species are spatially negatively correlated, especially at short distances. Interestingly, all three cases showing short-distance attraction of dbh marks are associated with light-demanding shrub species. The short-distance attraction of dbh marks indicates spatially aggregated cohorts of stems of similar size. The percentage of species showing significant dbh suppression peaked at a 4 m distance under the heterogeneous Poisson model. At scales exceeding the peak distance, the percentage of species showing significant dbh suppression decreases sharply with increasing distances. The evidence from this large observational study shows that some of the variation of the spatial characteristics of tree diameters is related variations of topography and soil chemistry. However, an obvious interpretation of this result is still lacking. Thus, removing competitors surrounding the target trees is an effective way to avoid neighboring competition effects reducing the growth of valuable target trees in forest management practice.

  17. Effects of annual and interannual environmental variability on soil fungi associated with an old-growth, temperate hardwood forest.

    Science.gov (United States)

    Burke, David J

    2015-06-01

    Seasonal and interannual variability in temperature, precipitation and chemical resources may regulate fungal community structure in forests but the effect of such variability is still poorly understood. In this study, I examined changes in fungal communities over two years and how these changes were correlated to natural variation in soil conditions. Soil cores were collected every month for three years from permanent plots established in an old-growth hardwood forest, and molecular methods were used to detect fungal species. Species richness and diversity were not consistent between years with richness and diversity significantly affected by season in one year but significantly affected by depth in the other year. These differences were associated with variation in late winter snow cover. Fungal communities significantly varied by plot location, season and depth and differences were consistent between years but fungal species within the community were not consistent in their seasonality or in their preference for certain soil depths. Some fungal species, however, were found to be consistently correlated with soil chemistry across sampled years. These results suggest that fungal community changes reflect the behavior of the individual species within the community pool and how those species respond to local resource availability. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Growth responses of young Douglas-fir and tanoak 11 years after various levels of hardwood removal and understory suppression in southwestern Oregon, USA

    Science.gov (United States)

    Harrington, T.B.; Tappeiner, John C.

    1997-01-01

    At two sites in southwestern Oregon, height, diameter, and crown width of young Douglas-fir (Pseudotsuga menziesii) and sprout-origin tanoak (Lithocarpus densiflorus) were measured 1–11 years after reducing the density of a 2-year-old tanoak stand to 0%, 25%, 50%, and 100% of its initial cover. Some plots also included suppression of understory vegetation. Tanoak cover developed linearly with time, with steepness of the growth trajectory increasing at a diminishing rate with increasing percentage of initial tanoak cover. Fifth-year cover of understory vegetation declined linearly with increasing percentage of initial tanoak cover (R2 = 0.29). Survival of Douglas-fir (96–100%) differed little among initial abundances of tanoak, while growth trajectories for its size became increasingly exponential with decreasing percentage of initial tanoak cover. Eleventh-year heights of Douglas-fir were similar for 0%, 25%, and 50% of initial tanoak cover; however, diameter increased linearly with decreasing percentage of initial tanoak cover (R2 = 0.73), and the slope of the relationship steepened with understory suppression. Our results indicate that young stands exhibiting a wide range of stand compositions and productivities can be established by early manipulations of tanoak and understory abundance. Complete removal of tanoak plus understory suppression are necessary to maximize Douglas-fir growth, while productive, mixed stands can be achieved by removing 50% or more of tanoak cover.

  19. Levels-of-growing-stock cooperative study on Douglas-fir: report no. 02—The Hoskins Study, 1963-1970.

    Science.gov (United States)

    John F. Bell; Alan B. Berg

    1972-01-01

    Public and private agencies are cooperating in a study of eight thinning regimes in young Douglas-fir stands. Regimes differ in the amount of basal area allowed to accrue in growing stock at each successive thinning. All regimes start with a common level-of-growing-stock which is established by a conditioning thinning. Thinning interval is...

  20. Patterns of Increasing Swiss Needle Cast Impacts on Growth of 20- and 40-year-old Douglas-fir from Tillamook

    Science.gov (United States)

    Currently, Swiss Needle Cast (SNC) is causing an epidemic west of the Oregon Coast Range from Coos Bay to Astoria. The most severely infected Douglas-fir trees are located on BLM land and Stimson Lumber plantations in Tillamook where environmental conditions are highly favorable ...

  1. Tree-ring history of Swiss needle cast impact on Douglas-fir growth in western Oregon: Correlations with climate variables

    Science.gov (United States)

    The fungal pathogen, Phaeocryptopus gaeumannii, occurs wherever Douglas-fir is found but disease damage is believed to be limited to the Coast Range and is of no concern outside the coastal fog zone (Shaw et al., 2011). However, knowledge remains limited on the history and spati...

  2. Residual densities affect growth of overstory trees and planted Douglas-fir, western hemlock, and western redcedar: results from the first decade

    Science.gov (United States)

    Leslie Chandler Brodie; Dean S. DeBell

    2013-01-01

    In recent years, interest has increased in silvicultural systems and harvest cuts that retain partial overstories, but there are few data available on the growth of the understory trees in such stands. We studied the response of overstory trees and underplanted seedlings, Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga...

  3. Effects of silviculture and genetics on branch/knot attributes of coastal Pacific Northwest Douglas-fir and implications for wood quality--a synthesis

    Science.gov (United States)

    Eini C. Lowell; Douglas A. Maguire; David G. Briggs; Eric C. Turnblom; Keith J.S. Jayawickrama; Jed. Bryce

    2014-01-01

    Douglas-fir is the most commercially important timber species in the US Pacific Northwest due to its ecological prevalence and its superior wood attributes, especially strength and stiffness properties that make it highly prized for structural applications. Its economic significance has led to extensive establishment and management of plantations over the last few...

  4. SEASONAL PATTERNS OF PHOTOSYNTHESIS IN DOUGLAS FIR SEEDLINGS DURING THE THIRD AND FOURTH YEAR OF EXPOSURE TO ELEVATED CO2 AND TEMPERATURE

    Science.gov (United States)

    We examined the interactive effects of elevated atmospheric CO2 and temperature on seasonal patterns of photosynthesis in Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings. Seedlings were grown in sunlit chambers controlled to track either ambient (~400 ppm) CO2 or am...

  5. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 19—The Iron Creek study, 1966–2006.

    Science.gov (United States)

    Robert O. Curtis; David D. Marshall

    2009-01-01

    This report documents the history and results of the Iron Creek installation of the cooperative Levels-of-Growing-Stock (LOGS) study in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), over the period 1966–2006 (ages 19 to 59). This is a 1949 plantation on an excellent site, and is one of nine installations in the study. Results are generally...

  6. Levels-of-growing-stock cooperative study in Douglas-fir: report no. 08—The LOGS Study, 20-year results.

    Science.gov (United States)

    Robert O. Curtis; David D. Marshall

    1986-01-01

    This progress report reviews the history and status of the cooperative levels-of-growing-stock study in coast Douglas-fir, begun in 1961, in Oregon, Washington, and British Columbia. It presents new analyses, including comparisons among some installations. Data now available are primarily from the site II installations, which are approaching completion of the study....

  7. Estimating tree biomass, carbon, and nitrogen in two vegetation control treatments in an 11-year-old Douglas-fir plantation on a highly productive site

    Science.gov (United States)

    Warren D. Devine; Paul W. Footen; Robert B. Harrison; Thomas A. Terry; Constance A. Harrington; Scott M. Holub; Peter J. Gould

    2013-01-01

    We sampled trees grown with and without competing vegetation control in an 11-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) plantation on a highly productive site in southwestern Washington to create diameter based allometric equations for estimating individual-tree bole, branch, foliar, and total...

  8. The relation between fine root density and proximity of stems in closed Douglas-fir plantations on homogen[e]ous sandy soils: implications for sampling design

    NARCIS (Netherlands)

    Olsthoorn, A.F.M.; Klap, J.M.; Oude Voshaar, J.H.

    1999-01-01

    Studies have been carried out in two fully stocked, fast growing Douglas-fir plantations of the Dutch ACIFORN project in three consecutive years, to obtain information on fine root densities (Olsthoorn 1991). For the present paper, data collected in early summer 1987 were used to study the relation

  9. THE KINETICS OF NH(4)+ AND NO3(-) UPTAKE BY DOUGLAS-FIR FROM SINGLE N-SOLUTIONS AND FROM SOLUTIONS CONTAINING BOTH NH(4)+ AND NO3(-)

    NARCIS (Netherlands)

    KAMMINGAVANWIJK, C; PRINS, HBA

    The kinetics of NH4+ and NO3- uptake in young Douglas fir trees (Pseudotsuga menziesii [Mirb.] Franco) were studied in solutions, containing either one or both N species. Using solutions containing a single N species, the V(max) of NH4+ uptake was higher than that of NO3- uptake. The K(m) of NH4+

  10. ELEVATED CO2 AND ELEVATED TEMPERATURE HAVE NO EFFECT ON DOUGLAS-FIR FINE-ROOT DYNAMICS IN NITROGEN-POOR SOIL

    Science.gov (United States)

    Here, we investigate fine-root production, mortality and standing crop of Douglas-fir (Pseudotsuga menziesii) seedlings exposed to elevated atmospheric CO2 and elevated air temperature. We hypothesized that these treatments would increase fine-root production, but that mortality ...

  11. Monitoring larval populations of the Douglas-fir tussock moth and the western spruce budworm on permanent plots: sampling methods and statistical properties of data

    Science.gov (United States)

    A.R. Mason; H.G. Paul

    1994-01-01

    Procedures for monitoring larval populations of the Douglas-fir tussock moth and the western spruce budworm are recommended based on many years experience in sampling these species in eastern Oregon and Washington. It is shown that statistically reliable estimates of larval density can be made for a population by sampling host trees in a series of permanent plots in a...

  12. Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades.

    Science.gov (United States)

    Ronald Heninger; William Scott; Alex Dobkowski; Richard Miller; Harry Anderson; Steve Duke

    2002-01-01

    We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at...

  13. The relationship between Swiss needle cast symptom severity and level of Phaeocryptopus gaeumannii colonization in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii).

    Science.gov (United States)

    F. Temel; G.R. Johnson; J.K. Stone

    2004-01-01

    This study examined 108 15-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii trees to investigate whether trees exhibiting less severe Swiss needle cast (SNC) symptoms were more resistant (had less fungal colonization) or more tolerant (maintained healthy foliage under similar infection levels). Trees were sampled from...

  14. Strong links between teleconnections and ecosystem exchange found at a Pacific Northwest old-growth forest from flux tower and MODIS EVI data

    Science.gov (United States)

    Sonia Wharton; Laura Chasmer; Matthias Falk; Kyaw Tha Paw U

    2009-01-01

    Variability in three Pacific teleconnection patterns are examined to see if net carbon exchange at a low-elevation, old-growth forest is affected by climatic changes associated with these periodicities. Examined are the Pacific Decadal Oscillation (PDO), Pacific/North American Oscillation (PNA) and EI Nino-Southern Oscillation (ENSO). We use 9 years of eddy covariance...

  15. Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, LA Selva, Costa Rica

    Science.gov (United States)

    Luitgard Schwendenmann; Edzo Veldkamp; Tania Brenes; Joseph J. O' Brien; Jens Mackensen

    2003-01-01

    Our objectives were to quantify and compare soil CO2, efflux of two doininant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental Factors on CO2, release. We measured soil CO2 efflux from eight permanent soil chamhers on...

  16. Tree communities of lowland warm-temperate old-growth and neighboring shelterbelt forests in the Shikoku region of southwestern Japan

    Science.gov (United States)

    Shigeo Kuramoto; Shigenori Oshioka; Takahisa Hirayama; Kaori Sato; Yasumasa Hirata

    2007-01-01

    We characterized the tree species composition of a 30 ha old-growth and neighboring shelterbelt (reserved buffer strips among conifer plantations) in warm-temperate forests in the Shikoku region of southwestern Japan. Using a two-way indicator species analysis of data from 28 plots, we identified four structural groups in terms of relative basal area. These structural...

  17. The application of LANDSAT remote sensing technology to natural resources management. Section 1: Introduction to VICAR - Image classification module. Section 2: Forest resource assessment of Humboldt County.

    Science.gov (United States)

    Fox, L., III (Principal Investigator); Mayer, K. E.

    1980-01-01

    A teaching module on image classification procedures using the VICAR computer software package was developed to optimize the training benefits for users of the VICAR programs. The field test of the module is discussed. An intensive forest land inventory strategy was developed for Humboldt County. The results indicate that LANDSAT data can be computer classified to yield site specific forest resource information with high accuracy (82%). The "Douglas-fir 80%" category was found to cover approximately 21% of the county and "Mixed Conifer 80%" covering about 13%. The "Redwood 80%" resource category, which represented dense old growth trees as well as large second growth, comprised 4.0% of the total vegetation mosaic. Furthermore, the "Brush" and "Brush-Regeneration" categories were found to be a significant part of the vegetative community, with area estimates of 9.4 and 10.0%.

  18. Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.

    Science.gov (United States)

    Cronn, Richard; Dolan, Peter C; Jogdeo, Sanjuro; Wegrzyn, Jill L; Neale, David B; St Clair, J Bradley; Denver, Dee R

    2017-07-24

    Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales. Using mRNA sequencing, we sampled 6.1 × 10 9 reads from 19 trees and constructed a de novo pan-transcriptome reference that includes 173,882 tree-derived transcripts. Using this reference, we mapped RNA-Seq reads from 179 samples that capture daily and annual variation. We identified 12,042 diurnally-cyclic transcripts, 9299 of which showed homology to annotated genes from other plant genomes, including angiosperm core clock genes. Annual analysis revealed 21,225 circannual transcripts, 17,335 of which showed homology to annotated genes from other plant genomes. The timing of maximum gene expression is associated with light intensity at diurnal scales and photoperiod at annual scales, with approximately half of transcripts reaching maximum expression +/- 2 h from sunrise and sunset, and +/- 20 days from winter and summer solstices. Comparisons with published studies from other conifers shows congruent behavior in clock genes with Japanese cedar (Cryptomeria), and a significant preservation of gene expression patterns for 2278 putative orthologs from Douglas-fir during the summer growing season, and 760 putative orthologs from spruce (Picea) during the transition from fall to winter. Our study highlight the extensive diurnal and circannual transcriptome variability demonstrated in conifer needles. At these temporal scales, 29% of expressed transcripts show a significant diurnal cycle, and 58.7% show a significant circannual cycle. Remarkably

  19. Treefall gap disturbance in an old-growth beech forest in southwestern Japan by a catastrophic typhoon

    International Nuclear Information System (INIS)

    Ida, Hideyuki

    2000-01-01

    In 1991, the catastrophic Typhoon 9119 created many treefall gaps in an old-growth beech (Fagus crenata) forest on Mt. Garyu, southwestern Japan. In a 3.3-ha plot, the density and basal area of fatally damaged trunks (DBH ≥ 20 cm) were 29.1 trunks/ha (16.9% of all pre-typhoon trunks) and 9.1 m 2 /ha. (24.4% of total pre-typhoon basal area), respectively. Many of the dominant beech were lost and larger trunks were damaged. The pre- and post-typhoon DBH distribution both had an inverse J-shape. Spatial distribution of living trunks was not random but clustered irrespective of typhoon damage or DBH size, suggesting that the stand structure of the study plot would be an unusual one as compared with the previous study stands in Japanese beech forests. The death of pre-typhoon trunks, seemed to die standing or to be killed by snap-off, occurred singly; however, the typhoon fatally damaged many clustered trunks at the same time. Uprooting was the most frequent cause of gaps created by the typhoon. The intermediate DBH size class (40 - 70 cm) would be more likely to be uprooted than snapped-off. The DBH distribution of snap-off may reflect the total pre-typhoon trunk distribution. Branch-fall had a flat DBH distribution. Uprooting might have a clustered distribution, while snap-off and branch-fall both had random distributions. The smaller trunks of snap-off and branch-fall seemed to result from injuries caused by the fall of larger trunks

  20. Ethanol synthesis and aerobic respiration in the laboratory by leader segments of Douglas-fir seedlings from winter and spring.

    Science.gov (United States)

    Joseph, Gladwin; Kelsey, Rick G

    2004-05-01

    Stem segments from terminal leaders of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, seedlings were sampled in mid-December when cambial cells were dormant. The residual, debudded leaders were resampled again in early May when the cambium was metabolically active. May stems had higher constitutive ethanol concentrations than December stems. This was not the result of cambial hypoxia generated by rapid spring respiration rates, because when aerobic respiration was stimulated by incubating the stems in air at 30 degrees C ethanol production was induced in December, but not in May. Rapid respiration rates at 30 degrees C may have depleted O(2) supplies and induced ethanol production in December stems because dormant, thick-walled cambial cells may be less permeable to CO(2) and O(2), compared with metabolically active, thin-walled cambial cells in May. December stem segments incubated in a N(2) atmosphere at 30 degrees C synthesized 1.8 times more ethanol than segments from May, most likely because spring growth had reduced the soluble sugars available for fermentation. CO(2) efflux from May stems (after 5.5 h of incubation at 30 degrees C) was equal to December stems per unit volume, but greater than December stems per unit surface area. N(2)-induced ethanol concentrations were positively related with CO(2) efflux per unit volume, indicating that rapidly respiring leaders can maintain rapid fermentation rates, provided soluble sugars are readily available. N(2)-induced ethanol and CO(2) efflux per unit volume declined with increasing leader diameter in both seasons, whereas there were no relationships between CO(2) efflux per unit surface area and diameter. Cambium physiology and phenology influence the induction of fermentation and concentrations of ethanol produced in terminal leaders of Douglas-fir, and probably other conifers as well. This needs to be considered when comparing fermentation among species, or comparing individuals from different seasons, or

  1. Functional structure of ant and termite assemblages in old growth forest, logged forest and oil palm plantation in Malaysian Borneo

    OpenAIRE

    Luke, Sarah H.; Fayle, Tom M.; Eggleton, Paul; Turner, Edgar C.; Davies, Richard G.

    2014-01-01

    Forested tropical landscapes around the world are being extensively logged and converted to agriculture, with serious consequences for biodiversity and potentially ecosystem functioning. Here we investigate associations between habitat disturbance and functional diversity of ants and termites – two numerically dominant and functionally important taxa in tropical rain forests that perform key roles in predation, decomposition, nutrient cycling and seed dispersal. We compared ant and termite oc...

  2. Comparative Structural Dynamics of the Janj Mixed Old-Growth Mountain Forest in Bosnia and Herzegovina: Are Conifers in a Long-Term Decline?

    Directory of Open Access Journals (Sweden)

    Srdjan Keren

    2014-06-01

    Full Text Available Regression of conifers in European mixed old-growth mountain forests has been observed for a long period and studied from different aspects. Old-growth (OG forests in Bosnia and Herzegovina (BiH have not experienced heavy air pollution and chronic overbrowsing that have affected many other European OG forests, while climatic and anthropogenic disturbances have been well documented. We analysed stand structure in the Janj OG forest, compared it with inventories of Lom and Perucica OG forests (BiH and with earlier inventories of the same reserves. At present, OG forest Janj is characterized by a high growing stock (1215 m3∙ha−1. This is due to good site quality, prevalence of conifers (84% and dominant endogenous processes in recent decades. In all three OG forests, indicators of structural change exhibited progression of European beech over time. Historical evidence revealed the occurrence of warm summers and droughts followed by bark beetle outbreaks in the 1920s, 1940s and early 1950s, which in turn influenced a marked conifer decline. It seems likely that repeated canopy opening released waves of European beech regeneration. These stand structural changes have delayed the rejuvenation of conifers and can help explain the early observations of conifer decline.

  3. Investigation of the particle size distribution and particle density characteristics of Douglas fir hogged fuel fly ash collected under known combustion conditions. Technical Progress Report No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Lang, A.J.; Junge, D.C.

    1978-12-01

    The increased interest in wood as a fuel source, coupled with the increasing demand to control the emission generated by wood combustion, has created a need for information characterizing the emissions that occur for given combustion conditions. This investigation characterizes the carbon char and inorganic fly ash size and density distribution for each of thirty-eight Douglas fir bark samples collected under known conditions of combustion.

  4. Comparison of leaf gas exchange and stable isotope signature of water-soluble compounds along canopy gradients of co-occurring Douglas-fir and European beech.

    Science.gov (United States)

    Bögelein, Rebekka; Hassdenteufel, Martin; Thomas, Frank M; Werner, Willy

    2012-07-01

    Combined δ(13) C and δ(18) O analyses of water-soluble leaf and twig phloem material were used to determine intrinsic water-use efficiency (iWUE) and variability of stomatal conductance at different crown positions in adult European beech (Fagus sylvatica) and Douglas-fir (Pseudotsuga menziesii) trees. Simultaneous gas exchange measurements allowed evaluation of the differences in calculating iWUE from leaf or phloem water-soluble compounds, and comparison with a semi-quantitative dual isotope model to infer variability of net photosynthesis (A(n) ) between the investigated crown positions. Estimates of iWUE from δ(13) C of leaf water-soluble organic matter (WSOM) outperformed the estimates from phloem compounds. In the beech crown, δ(13) C of leaf WSOM coincided clearly with gas exchange measurements. The relationship was not as reliable in the Douglas-fir. The differences in δ(18) O between leaf and phloem material were found to correlate with stomatal conductance. The semi-quantitative model approach was applicable for comparisons of daily average A(n) between different crown positions and trees. Intracanopy gradients were more pronounced in the beech than in the Douglas-fir, which reached higher values of iWUE at the respective positions, particularly under dry air conditions. © 2012 Blackwell Publishing Ltd.

  5. Temporal dynamics of tree source water in sky island ecosystems with ephemeral snow pack: a case study using Pseudotsuga menziesii (Douglas Fir)

    Science.gov (United States)

    Papuga, S. A.; Hamann, L.

    2017-12-01

    In semiarid regions, such as the desert southwest, water is a scarce resource that demands careful attention to its movement throughout the environment for accurate accounting in regional water budgets. Ephemeral snow pack in sky island ecosystems delivers a large fraction of the water resources to communities lower in the watershed. Because the major source of loss to those water resources is evapotranspiration (ET), any change in ET in these ecosystems will have major implications downstream. Climate scientists predict more intense and less frequent precipitation events in the desert southwest, which will alter the existing soil-plant-atmosphere continuum (SPAC). Therefore, understanding how water currently moves within that continuum is imperative in preparing for these predicted changes. This study used stable isotopes (δ18O and δD) to study the SPAC that exists in the Santa Catalina Mountain Critical Zone Observatory (SCM-CZO) to determine where the dominant tree species (Pseudotsuga menziesii, a.k.a., Douglas Fir) retrieves its water from and whether that source varies with season. We hypothesize that the Douglas Fir uses shallow soil water (season and deeper soil water (> 40 cm) during the snowmelt season. The findings of this work will help to better account for water losses due to ET and the movement of water throughout the environment. With a shift in the SPAC dynamics, the Douglas Fir may become increasingly water stressed effecting its ability to survive in the desert southwest which will have important consequences for water resources in this region.

  6. Metal stress and decreased tree growth in response to biosolids application in greenhouse seedlings and in situ Douglas-fir stands

    International Nuclear Information System (INIS)

    Cline, Erica T.; Nguyen, Quyen T.N.; Rollins, Lucy; Gawel, James E.

    2012-01-01

    To assess physiological impacts of biosolids on trees, metal contaminants and phytochelatins were measured in Douglas-fir stands amended with biosolids in 1982. A subsequent greenhouse study compared these same soils to soils amended with fresh wastewater treatment plant biosolids. Biosolids-amended field soils had significantly higher organic matter, lower pH, and elevated metals even after 25 years. In the field study, no beneficial growth effects were detected in biosolids-amended stands and in the greenhouse study both fresh and historic biosolids amendments resulted in lower seedling growth rates. Phytochelatins – bioindicators of intracellular metal stress – were elevated in foliage of biosolids-amended stands, and significantly higher in roots of seedlings grown with fresh biosolids. These results demonstrate that biosolids amendments have short- and long-term negative effects that may counteract the expected tree growth benefits. - Highlights: ► Biosolids amendment increases soil metals over 25 years later. ► Douglas-fir growth benefits fail to materialize from biosolids amendments. ► Phytochelatins are elevated in foliage of trees and roots of greenhouse seedlings after new biosolids are added to soil. ► Biosolids connected to metal stress in Douglas-fir. - Biosolids applications increase bioindicators of intracellular metal stress and may counteract tree growth benefits.

  7. Status and conservation of old-growth forests and endemic birds in the pine-oak zone of the Sierra Madre occidental Mexico

    OpenAIRE

    Lammertink, J.M.; Rojas-Tome, J.A.; Casillas-Orona, F.M.; Otto, R.L.

    1996-01-01

    The pine-oak forests of the Sierra Madre Occidental, a mountain range in NW Mexico, have recently been recognized as an area of high endemism and biodiversity. Selective logging threatens three bird species endemic to this habitat, who depend on standing dead trees (snags). This report is based on an 11 month field survey that aimed to locate oldgrowth remnants and to assess the status of the endemic birds. Old-growth is defined here as a forest that has never been logged mechanically. Old-gr...

  8. Forest restoration at Redwood National Park: exploring prescribed fire alternatives to second-growth management: a case study

    Science.gov (United States)

    Engber, Eamon; Teraoka, Jason; van Mantgem, Phillip J.

    2017-01-01

    Almost half of Redwood National Park is comprised of second-growth forests characterized by high stand density, deficient redwood composition, and low understory biodiversity. Typical structure of young redwood stands impedes the recovery of old-growth conditions, such as dominance of redwood (Sequoia sempervirens (D. Don) Endl.), distinct canopy layers and diverse understory vegetation. Young forests are commonly comprised of dense, even-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and redwood stump sprouts, with simple canopy structure and little understory development. Moreover, many of these young stands are believed to be vulnerable to disturbance in the form of drought, disease and fire. Silvicultural practices are increasingly being employed by conservation agencies to restore degraded forests throughout the coast redwood range; however, prescribed fire treatments are less common and potentially under-utilized as a restoration tool. We present an early synthesis from three separate management-scale prescribed fire projects at Redwood National Park spanning 1to 7 years post-treatment. Low intensity prescribed fire had minimal effect on overstory structure, with some mortality observed in trees smaller than 30 cm diameter. Moderate to high intensity fire may be required to reduce densities of larger Douglas-fir, the primary competitor of redwood in the Park’s second growth forests. Fine woody surface fuels fully recovered by 7 years post-burn, while recruitment of larger surface fuels was quite variable. Managers of coastal redwood ecosystems will benefit by having a variety of tools at their disposal for forest restoration and management.

  9. Fate of nitrogenous fertilizers in forest soil

    International Nuclear Information System (INIS)

    Pang, P.C.K.

    1984-01-01

    The fate of the nitrogenous fertilizers through the processes of denitrification, ammonia volatilization, immobilization and uptake by a conifer is determined, with the aid of 15 N-labelled fertizers. The foliage of Douglas-fir was able to absorb gaseous ammonia under optimal conditions. Denitrification and immobilization of fertilizer-N by forest soil were highest with forest floor samples and decreased with depth. Laboratory studies with four-year-old Douglas-fir demostrated that a higher quantity of fertilizer-N was utilized by trees when the nitrogen was supplied as NO 3 - rather than NH 4 + . (M.A.C.) [pt

  10. Disturbance history and stand dynamics in secondary and old-growth forests of the Southern Appalachian Mountains, USA

    Science.gov (United States)

    Sarah M. Butler; Alan S. White; Katherine J. Elliott; Robert S Seymour

    2014-01-01

    BUTLER, S. M. (Family Forest Research Center, University of Massachusetts, Amherst, MA 01003), A. S. WHITE (School of Forest Resources, University of Maine, Orono, ME 04469-5755), K. J. ELLIOTT (Coweeta Hydrologic Laboratory, Center for Forest Watershed Science, Southern Research Station, USDA Forest Service, Otto, NC 28763) AND R. S. SEYMOUR (School of Forest...

  11. Two-Step Hot-Compressed Water Treatment of Douglas Fir for Efficient Total Sugar Recovery by Enzymatic Hydrolysis

    Directory of Open Access Journals (Sweden)

    Hiroyuki Inoue

    2016-04-01

    Full Text Available The non-catalytic hydrothermal pretreatment of softwood is generally less effective for subsequent enzymatic hydrolysis. In this study, the efficacy of hot-compressed water (HCW treatment of Douglas fir was investigated between 180 °C and 260 °C, allowing solubilization of the cellulose components. The enzymatic digestibility of cellulosic residues increased significantly under HCW conditions > 250 °C, and the enhanced glucan digestibility was closely related to the decomposition of the cellulose component. Combination of the first-stage HCW treatment (220 °C, 5 min to recover hemicellulosic sugars with the second-stage HCW treatment (260 °C, 5 min to improve cellulose digestibility gave a total sugar recovery of 56.2% based on the dried raw materials. This yield was 1.4 times higher than that from the one-step HCW-treated sample (260 °C, 5 min. Additionally, an enzymatic hydrolysate from the two-step HCW-treated sample exceeded 90% of the ethanol fermentation yield based on the total sugars present in the hydrolysates. These results suggest the potential of the two-step HCW treatment of softwood as a pretreatment technology for efficient total sugar recovery and ethanol production.

  12. Ectomycorrhizal mats alter forest soil biogeochemistry

    Science.gov (United States)

    Laurel A. Kluber; Kathryn M. Tinnesand; Bruce A. Caldwell; Susie M. Dunham; Rockie R. Yarwood; Peter J. Bottomley; David D. Myrold

    2010-01-01

    Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir forest ecosystems, and have been estimated to cover up to 40% of the soil surface in some forest stands. Two morphotypes of EcM mats have been previously described: rhizomorphic mats, which have thick hyphal rhizomorphs and are found primarily in the organic horizon, and...

  13. Effect of thinning, fertilization with biosolids, and weather on interannual ring specific gravity and carbon accumulation of a 55-year-old Douglas-fir stand in western Washington

    Energy Technology Data Exchange (ETDEWEB)

    Kantavichai, R.; Briggs, D.G.; Turnblom, E.C. [Washington Univ., Seattle, WA (United States). School of Forest Resources

    2010-01-15

    Soil moisture deficits (SMD) cause trees to conserve water by closing stomata, which in turn limits the uptake of atmospheric carbon dioxide (CO{sub 2}) and curtails photosynthesis and wood formation. This study investigated the combined effect of temperature, precipitation, SMD, and various silviculture treatments on interannual ring specific gravity (SG). A model was developed to predict post-treatment interannual ring SG from the treatment and environmental variables. The study assumed that thinning the stand would increase SG, while fertilization with biosolids would decrease SG. The SGs associated with each treatment were then used to calculate the dry mass and carbon content associated with stem growth. Results were then compared with estimates taken from standard publications. The experiment was conducted on a 55-year old Douglas fir stand. Twelve rings were used to assess the effect of the treatments. The study showed that use of the published average to consider only carbon sequestered by tree growth distorts the comparison of management regimes. The thinning process produced logs from which long-term structures were built, and continue to sequester carbon. When product pools of stored carbon are combined with forest carbon pools, thinning and biosolids treatment regimes are preferable to other carbon storage regimes. 40 refs., 6 tabs., 2 figs.

  14. Facilitative-competitive interactions in an old-growth forest: the importance of large-diameter trees as benefactors and stimulators for forest community assembly.

    Science.gov (United States)

    Fichtner, Andreas; Forrester, David I; Härdtle, Werner; Sturm, Knut; von Oheimb, Goddert

    2015-01-01

    The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica) forest by quantifying variation in the intensity of above- (shading) and belowground competition (crowding) among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services.

  15. Facilitative-competitive interactions in an old-growth forest: the importance of large-diameter trees as benefactors and stimulators for forest community assembly.

    Directory of Open Access Journals (Sweden)

    Andreas Fichtner

    Full Text Available The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica forest by quantifying variation in the intensity of above- (shading and belowground competition (crowding among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services.

  16. Facilitative-Competitive Interactions in an Old-Growth Forest: The Importance of Large-Diameter Trees as Benefactors and Stimulators for Forest Community Assembly

    Science.gov (United States)

    Fichtner, Andreas; Forrester, David I.; Härdtle, Werner; Sturm, Knut; von Oheimb, Goddert

    2015-01-01

    The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica) forest by quantifying variation in the intensity of above- (shading) and belowground competition (crowding) among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services. PMID:25803035

  17. Measured and modeled evidence for a two-fold increase in water use efficiency at an old-growth forest site in the Pacific Northwest

    Science.gov (United States)

    Jiang, Y.; Rastogi, B.; Kim, J. B.; Voelker, S.; Meinzer, F. C.; Still, C. J.

    2017-12-01

    Water use efficiency (WUE), the ratio of carbon uptake to transpiration, has been widely recognized as an important measure of carbon and water cycling in plants, and is used to track forest ecosystem responses to climate change and rising atmospheric CO2concentrations. In this study we used eddy covariance measurement data and Ecosystem Demography model (ED2) simulations to explore the patterns and physiological and biophysical controls of WUE at Wind River Experimental Forest, an old-growth coniferous forest in the Pacific Northwest. We characterized how observed and simulated WUE vary between wet and dry years, and explored the drivers of the differences in WUE between the wet and dry years. Through this explorative process, we evaluated the utility of various ways that WUE have been computed in literature. Measurement-based and simulated WUE at the old-growth forest increased over twofold from 1998 to 2015. The primary driver of this trend is a decreasing trend in evapotranspiration (ET). There were significant inter-annual variations. For example, during drought years, higher air temperature drove increases in early season ET, thereby depleting soil water and decreasing GPP. Lower GPP in turn resulted in lower WUE. This mechanism might drive changes in future carbon and water budgets under warming climate. Our evaluation of multiple WUE metrics demonstrates that each metric has a distinct sensitivity to climate anomalies, but also indicates a robust increasing trend of WUE. Statistical (multiple linear regression) and machine learning (Random Forest) analyses of flux measurements indicated that atmospheric CO2 concentration, air temperature and radiation were the most important predictors of WUE at monthly, daily and half-hourly time scale, respectively. In contrast, WUE mechanism was stable across all time scales in ED2 simulations: vapor pressure deficit was consistently the most important predictor of WUE at the monthly, daily and half-hourly time scales.

  18. Contrasting Spatial Patterns in Active-Fire and Fire-Suppressed Mediterranean Climate Old-Growth Mixed Conifer Forests

    OpenAIRE

    Fry, Danny L.; Stephens, Scott L.; Collins, Brandon M.; North, Malcolm P.; Franco-Vizcaíno, Ernesto; Gill, Samantha J.

    2014-01-01

    In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbanc...

  19. Slow and fast pyrolysis of Douglas-fir lignin: Importance of liquid-intermediate formation on the distribution of products

    International Nuclear Information System (INIS)

    Zhou, Shuai; Pecha, Brennan; Kuppevelt, Michiel van; McDonald, Armando G.; Garcia-Perez, Manuel

    2014-01-01

    The formation of liquid intermediates and the distribution of products were studied under slow and fast pyrolysis conditions. Results indicate that monomers are formed from lignin oligomeric products during secondary reactions, rather than directly from the native lignin. Lignin from Douglas-fir (Pseudotsuga menziesii) wood was extracted using the milled wood enzyme lignin isolation method. Slow pyrolysis using a microscope with hot-stage captured the liquid formation (>150 °C), shrinking, swelling (foaming), and evaporation behavior of lignin intermediates. The activation energy (E a ) for 5–80% conversions was 213 kJ mol −1 , and the pre-exponential factor (log A) was 24.34. Fast pyrolysis tests in a wire mesh reactor were conducted (300–650 °C). The formation of the liquid intermediate was visualized with a fast speed camera (250 Hz), showing the existence of three well defined steps: formation of lignin liquid intermediates, foaming and liquid intermediate swelling, and evaporation and droplet shrinking. GC/MS and UV-Fluorescence of the mesh reactor condensate revealed lignin oligomer formation but no mono-phenols were seen. An increase in pyrolytic lignin yield was observed as temperature increased. The molar mass determined by ESI-MS was not affected by pyrolysis temperature. SEM of the char showed a smooth surface with holes, evidence of a liquid intermediate with foaming; bursting from these foams could be responsible for the removal of lignin oligomers. Py-GC/MS studies showed the highest yield of guaiacol compounds at 450–550 °C. - Highlights: • The formation of a liquid intermediate phase is a critical step during lignin pyrolysis. • The lignin oligomers are thermally ejected from the liquid intermediate phase. • The mono-phenols are formed mainly from the secondary reactions of lignin oligomers

  20. Variation in water potential, hydraulic characteristics and water source use in montane Douglas-fir and lodgepole pine trees in southwestern Alberta and consequences for seasonal changes in photosynthetic capacity.

    Science.gov (United States)

    Andrews, Shilo F; Flanagan, Lawrence B; Sharp, Eric J; Cai, Tiebo

    2012-02-01

    Tree species response to climate change-induced shifts in the hydrological cycle depends on many physiological traits, particularly variation in water relations characteristics. We evaluated differences in shoot water potential, vulnerability of branches to reductions in hydraulic conductivity, and water source use between Pinus contorta Dougl. ex Loud. var. latifolia Engelm. (lodgepole pine) and Pseudotsuga menziesii (Mirb.) Franco (interior Douglas-fir), and determined the consequences for seasonal changes in photosynthetic capacity. The Douglas-fir site had soil with greater depth, finer texture and higher organic matter content than soil at the lodgepole pine site, all factors that increased the storage of soil moisture. While the measured xylem vulnerability curves were quite similar for the two species, Douglas-fir had lower average midday shoot water potentials than did lodgepole pine. This implied that lodgepole pine exhibited stronger stomatal control of transpiration than Douglas-fir, which helped to reduce the magnitude of the water potential gradient required to access water from drying soil. Stable hydrogen isotope measurements indicated that Douglas-fir increased the use of groundwater during mid-summer when precipitation inputs were low, while lodgepole pine did not. There was a greater reduction of photosynthetic carbon gain in lodgepole pine compared with Douglas-fir when the two tree species were exposed to seasonal declines in soil water content. The contrasting patterns of seasonal variation in photosynthetic capacity observed for the two species were a combined result of differences in soil characteristics at the separate sites and the inherent physiological differences between the species.

  1. Nutritional hotspots and the secret life of forests

    Science.gov (United States)

    Jane Smith; Laurel Kluber; Noreen Parks

    2014-01-01

    The floor of a Douglas-fir forest may be rich in organic matter, but nutrients essential to plant growth are locked within the decomposing needles, leaves, and fallen wood. Before nitrogen, phosphorus, and other nutrients can be cycled back through the forest system, they need to be further broken down into forms accessible to plants. Understanding how nutrients become...

  2. Estimating air drying times of small-diameter ponderosa pine and Douglas-fir logs.

    Science.gov (United States)

    William T. Simpson; Xiping. Wang

    2003-01-01

    Because dense stands of softwood trees are causing forest health problems in the western United States, new ways to use this material need to be found. One option is to use this material as logs rather than sawing it into lumber. For many applications, logs require some degree of drying. Even though these logs may be considered small diameter, they are large compared...

  3. Virulence of Fusarium oxysporum and F. commune to Douglas-fir (Pseudotsuga menziesii) seedlings

    Science.gov (United States)

    J. E. Stewart; Z. Abdo; R. K. Dumroese; N. B. Klopfenstein; M. -S. Kim

    2012-01-01

    Fusarium species can cause damping-off and root rot of young conifer seedlings, resulting in severe crop and economic losses in forest nurseries. Disease control within tree nurseries is difficult because of the inability to characterize and quantify Fusarium spp. populations with regard to disease potential because of high variability in isolate virulence. Fusarium...

  4. Fusarium oxysporum protects Douglas-fir (Pseudotsuga menziesii) seedlings from root disease caused by Fusarium commune

    Science.gov (United States)

    R. Kasten Dumroese; Mee-Sook Kim; Robert L. James

    2012-01-01

    Fusarium root disease can be a serious problem in forest and conservation nurseries in the western United States. Fusarium inoculum is commonly found in most container and bareroot nurseries on healthy and diseased seedlings, in nursery soils, and on conifer seeds. Fusarium spp. within the F. oxysporum species complex have been recognized as pathogens for more than a...

  5. Gene activity test determines cold tolerance in Douglas-fir seedlings

    Science.gov (United States)

    Peter A. Balk; Diane L. Haase; Monique F. van Wordragen

    2008-01-01

    Forest tree nurseries rely on a tight scheduling of operations to be able to deliver vigorous seedlings to the planting site. Cooler or freezer storage is often used to maintain planting stock in an inactive condition and to ensure a plant supply for geographically diverse planting sites, which is a requirement for large-scale or internationally operating nurseries....

  6. Soil acidification effects on fine root growth of Douglas-fir on sandy soils

    NARCIS (Netherlands)

    Olsthoorn, A.F.M.

    1998-01-01

    The ammonium sulphate deposited in forest ecosystems in the Netherlands as a result of air pollution currently exceeds 80 kg N ha -1yr -1locally. To study the influence of this air pollution on fine root density and its dynamics, fine root

  7. Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests

    Science.gov (United States)

    Danny L. Fry; Scott L. Stephens; Brandon M. Collins; Malcolm North; Ernesto Franco-Vizcaino; Samantha J. Gill

    2014-01-01

    In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference...

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

  9. Epiphytic lichens of Stužica (E Slovakia) in the context of Central European old-growth forests

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jan; Malíček, J.; Šoun, J.; Pouska, V.

    2015-01-01

    Roč. 28, č. 1 (2015), s. 104-126 ISSN 0018-0971 Institutional support: RVO:67985939 Keywords : beech forest * diversity inventory * Sorensen's similarity index Subject RIV: EF - Botanics Impact factor: 0.821, year: 2015

  10. Effects of biotic and abiotic factors on resistance versus resilience of Douglas fir to drought.

    Directory of Open Access Journals (Sweden)

    Gunnar Carnwath

    Full Text Available Significant increases in tree mortality due to drought-induced physiological stress have been documented worldwide. This trend is likely to continue with increased frequency and severity of extreme drought events in the future. Therefore, understanding the factors that influence variability in drought responses among trees will be critical to predicting ecosystem responses to climate change and developing effective management actions. In this study, we used hierarchical mixed-effects models to analyze drought responses of Pseudotsuga menziesii in 20 unmanaged forests stands across a broad range of environmental conditions in northeastern Washington, USA. We aimed to 1 identify the biotic and abiotic attributes most closely associated with the responses of individual trees to drought and 2 quantify the variability in drought responses at different spatial scales. We found that growth rates and competition for resources significantly affected resistance to a severe drought event in 2001: slow-growing trees and trees growing in subordinate canopy positions and/or with more neighbors suffered greater declines in radial growth during the drought event. In contrast, the ability of a tree to return to normal growth when climatic conditions improved (resilience was unaffected by competition or relative growth rates. Drought responses were significantly influenced by tree age: older trees were more resistant but less resilient than younger trees. Finally, we found differences between resistance and resilience in spatial scale: a significant proportion (approximately 50% of the variability in drought resistance across the study area was at broad spatial scales (i.e. among different forest types, most likely due to differences in the total amount of precipitation received at different elevations; in contrast, variation in resilience was overwhelmingly (82% at the level of individual trees within stands and there was no difference in drought resilience

  11. Effects of Harvesting Systems and Bole Moisture Loss on Weight Scaling of Douglas-Fir Sawlogs (Pseudotsuga Menziesii var. glauca Franco

    Directory of Open Access Journals (Sweden)

    Jarred D. Saralecos

    2014-09-01

    Full Text Available Characterizing the moisture loss from felled trees is essential for determining weight-to-volume (W-V relationships in softwood sawlogs. Several factors affect moisture loss, but research to quantify the effects of bole size and harvest method is limited. This study was designed to test whether bole size, harvest method, environmental factors, and the associated changes in stem moisture content of felled Douglas-fir (Pseudotsuga menziesii var. glauca Franco affected the weight-to-volume relationship of sawlogs. Thirty trees in three size classes (12.7–25.4 cm, 25.5–38.1 cm, 38.2–50.8 cm were felled and treated with one of two harvesting processing methods. Moisture content was sampled every two days for four weeks. Results showed 6% greater moisture loss in the crowns of stems that retained limbs after felling compared to stems with limbs removed after harvesting. Additionally, moisture loss rate increased as stem size decreased. The smallest size class lost 58% moisture content compared to 34% in the largest size class throughout the study duration. These stem moisture content changes showed a 17% reduction in average sawlog weight within the largest size class, shifting current W-V relationships from 2.33 tons m−3 to 1.94 tons m−3 during the third seasonal quarter for northern Idaho Douglas-fir and potentially altering relationships year-round.

  12. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest (P-53)

    Science.gov (United States)

    Joseph E. Crouse; Margaret M. Moore; Peter Z. Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  13. Forest research notes, Pacific Northwest Forest Experiment Station, No. 23, November 27, 1937.

    Science.gov (United States)

    J. Elton Lodewick; P.A. Briegleb; F.L. Moravets; Leo A. Isaac; William G. Morris; Wade. DeVries

    1937-01-01

    Douglas fir, the most abundant and most used lumber species in the forests of the Pacific Northwest, is being pulped on a commercial scale by the sulfate and soda processes. The markets for unbleached pulps are limited, and there has been much speculation as to the possibilities of developing pulping processes whereby the enormous quantities of otherwise unutilized...

  14. Changes in forest species composition and structure after stand-replacing wildfire in the mountains of southeastern Arizona

    Science.gov (United States)

    Ronald D. Quinn; Lin Wu

    2005-01-01

    A wildfire in the Chiricahua Mountains of southeastern Arizona apparently altered the long-term structure of the forest. The pre-fire canopy forest, which had not burned for 100 years, was an even mixture of Arizona pines and Rocky Mountain Douglas-firs. A decade later the new forest was numerically dominated by quaking aspen seedlings in clumps separated by persistent...

  15. Pruning high-value Douglas-fir can reduce dwarf mistletoe severity and increase longevity in central Oregon

    Science.gov (United States)

    Maffei, Helen M; Filip, Gregory M; Gruelke, Nancy E; Oblinger, Brent W; Margolis, Ellis; Chadwick, Kristen L

    2016-01-01

    Mid- to very large-sized Douglas-fir (Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe (Arceuthobium douglasii) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without significantly affecting tree vitality and by inference, longevity. Immediate and longterm pruning effects on mistletoe infection severity were assessed by comparing pruned trees (n = 173) to unpruned trees (n = 55) with respect to: (1) percentage of trees with no visible infections 14 years post-pruning, (2) Broom Volume Rating (BVR), and (3) rate of BVR increase 14 years postpruning. Vitality/longevity (compared with unpruned trees) was assessed using six indicators: (1) tree survival, (2) the development of severe infections, (3) the development of dead tops, (4) tree-ring width indices, (5) Normalized Difference Vegetation Index (NDVI) from high-resolution multi-spectral imagery, and (6) live-crown ratio (LCR) and increment. Twenty-four percent of the pruned trees remained free of mistletoe 14 years post-pruning. Pruning is most likely to successfully eradicate mistletoe in lightly infected trees (BVR 1 or 2) without infected neighbors. Pruning significantly decreased mean BVR in the pruned versus the unpruned trees. However, the subsequent average rate of intensification (1.3–1.5 BVR per decade) was not affected, implying that a single pruning provides ~14 years respite in the progression of infection levels. Post-pruning infection intensification was slower on dominant and co-dominants than on intermediate or suppressed trees. The success of mistletoe eradication via pruning and need for follow-up pruning should be evaluated no sooner than 14 years after pruning to allow for the development of detectable brooms. Based on six indicators, foliage from witches brooms contribute little to long-term tree vitality since removal appears to have

  16. Impacts of Nitrogen Fertilization on Carbon and Water Balances in Different-aged Westcoast Douglas-fir Stands

    Science.gov (United States)

    Jassal, P.; Black, A.; Bruemmer, C.; Nesic, Z.; Spittlehouse, D.; Trofymow, T.

    2009-05-01

    Using the eddy-covariance technique, we have been measuring, since 1998, CO2, water vapour and energy exchange between the atmosphere and the ecosystem in three different-aged Westcoast Douglas-fir (Pseudotsuga menziesii) stands (9, 21 and 60 year-old in 2009, hereafter known as HDF00, HDF88 and DF49, respectively). These stands were fertilized with urea in January 2007. While HDF88 and DF49 were fertilized aerially with 200 kg N ha-1, HDF00, due to its young age and competing brush, was fertilized manually at 60 kg N ha-1. This paper reports the environmental controls of pre-fertilization interannual variability in ecosystem respiration (R), gross photosynthesis (P) and evapotranspiration (E), and discusses the effects of N- fertilization on these fluxes and net ecosystem productivity (NEP = P - R, i.e., carbon sequestration) and water use efficiency (WUE = P/E). For DF49, both pre-fertilization annual P and R responded positively to increases in mean annual air temperature and soil water content, but R was more responsive to both these environmental variables. Using these relationships, we calculated P and R for 2007 and 2008 assuming the stand was not fertilized. A comparison with measured 2007 and 2008 fluxes indicated that fertilization increased P and had almost no effect on R and soil respiration with the consequence that NEP was increased by 170 and 90 g C m- 2 during 2007 and 2008, respectively. Pre-fertilization annual E was modelled as a function of mean annual temperature, annual total photosynthetically active radiation, and precipitation for the previous year. Using this model to calculate 2007 and 2008 values of E for the unfertilized stand and comparing these with measured values in the fertilized stand indicated that fertilization had no effect on E, neither in 2007 nor in 2008. As a result, annual water use efficiency increased from a mean of 4.9 g C (kg water)-1 for 1998-2006 to 5.2 g C (kg water)-1 in 2007 and 2008. A similar analysis was

  17. New and interesting lichen records from old-growth forest stands in the German National Park Bayerischer Wald

    Czech Academy of Sciences Publication Activity Database

    Printzen, C.; Halda, J.; Palice, Zdeněk; Toensberg, T.

    2002-01-01

    Roč. 74, 1-2 (2002), s. 25-49 ISSN 0029-5035 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6005908 Keywords : lichens * forest stands * Bayerischer Wald National Park Subject RIV: EF - Botanics Impact factor: 0.588, year: 2002

  18. High retention of 15N-labeled nitrogen deposition in a nitrogen saturated old-growth tropical forest

    DEFF Research Database (Denmark)

    Gurmesa, Geshere Abdisa; Lu, Xiankai; Gundersen, Per

    2016-01-01

    ecosystem compartments were quantified 4 months after the last addition. Tracer recoveries in soil solution were monitored monthly to quantify leaching losses. Total tracer recovery in plant and soil (N retention) in the control plots was 72% and similar to those observed in temperate forests. The retention...

  19. Chromosera cyanophylla (Basidiomycota, Agaricales) a rare fungus of Central European old-growth forests and its habitat preferences in Europe

    Czech Academy of Sciences Publication Activity Database

    Holec, J.; Kříž, M.; Beran, M.; Kolařík, Miroslav

    2015-01-01

    Roč. 100, 1-2 (2015), s. 189-204 ISSN 0029-5035 Institutional support: RVO:61388971 Keywords : Omphalina cyanophylla * Boubinskyr prales virgin forest * Czech Republic Subject RIV: EE - Microbiology, Virology Impact factor: 0.876, year: 2015

  20. Alternatives to clearcutting in the old-growth forests of southeast Alaska: study plan and establishment report.

    Science.gov (United States)

    Michael H. McClellan; Douglas N. Swanston; Paul E. Hennon; Robert L. Deal; Toni L. de Santo; Mark S. Wipfli

    2000-01-01

    Much is known about the ecological effects, economics, and social impacts of clearcutting, but little documented experience with other silvicultural systems exists in southeast Alaska. The Pacific Northwest Research Station and the Alaska Region of the USDA Forest Service have cooperatively established an interdisciplinary study of ecosystem and social responses to...

  1. Simulating fuel treatment effects in dry forests of the western United States: testing the principles of a fire-safe forest

    Science.gov (United States)

    Morris C. Johnson; Maureen C Kennedy; David L. Peterson

    2011-01-01

    We used the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) to simulate fuel treatment effects on stands in low- to midelevation dry forests (e.g., ponderosa pine (Pinus ponderosa Dougl. ex. P. & C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) of the western United States. We...

  2. Effects of local biotic neighbors and habitat heterogeneity on tree and shrub seedling survival in an old-growth temperate forest.

    Science.gov (United States)

    Bai, Xuejiao; Queenborough, Simon A; Wang, Xugao; Zhang, Jian; Li, Buhang; Yuan, Zuoqiang; Xing, Dingliang; Lin, Fei; Ye, Ji; Hao, Zhanqing

    2012-11-01

    Seedling dynamics play a crucial role in determining species distributions and coexistence. Exploring causes of variation in seedling dynamics can therefore provide key insights into the factors affecting these phenomena. We examined the relative importance of biotic neighborhood processes and habitat heterogeneity using survival data for 5,827 seedlings in 39 tree and shrub species over 2 years from an old-growth temperate forest in northeastern China. We found significant negative density-dependence effects on survival of tree seedlings, and limited effects of habitat heterogeneity (edaphic and topographic variables) on survival of shrub seedlings. The importance of negative density dependence on young tree seedling survival was replaced by habitat in tree seedlings ≥ 4 years old. As expected, negative density dependence was more apparent in gravity-dispersed species compared to wind-dispersed and animal-dispersed species. Moreover, we found that a community compensatory trend existed for trees. Therefore, although negative density dependence was not as pervasive as in other forest communities, it is an important mechanism for the maintenance of community diversity in this temperate forest. We conclude that both negative density dependence and habitat heterogeneity drive seedling survival, but their relative importance varies with seedling age classes and species traits.

  3. Using tree recruitment patterns and fire history to guide restoration of an unlogged ponderosa pine/Douglas-fir landscape in the southern Rocky Mountains after a century of fire suppression

    Science.gov (United States)

    Merrill R. Kaufmann; Laurie S. Huckaby; Paula J. Fornwalt; Jason M. Stoker; William H. Romme

    2003-01-01

    Tree age and fire history were studied in an unlogged ponderosa pine/Douglas-fir (Pinus ponderosa/Pseudotsuga menziesii) landscape in the Colorado Front Range mountains. These data were analysed to understand tree survival during fire and post-fire recruitment patterns after fire, as a basis for understanding the characteristics of, and restoration needs for, an...

  4. Strong Links Between Teleconnections and Ecosystem Exchange Found at a Pacific Northwest Old-Growth Forest from Flux Tower and MODIS EVI Data

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Chasmer, L; Falk, M; Paw U, K T

    2009-03-12

    Variability in three Pacific teleconnection patterns are examined to see if net carbon exchange at a low-elevation, old-growth forest is affected by climatic changes associated with these periodicities. Examined are the Pacific Decadal Oscillation (PDO), Pacific/North American Oscillation (PNA) and El Nino-Southern Oscillation (ENSO). We use nine years of eddy covariance CO{sub 2}, H{sub 2}O and energy fluxes measured at the Wind River AmeriFlux site, Washington, USA and eight years of tower-pixel remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to address this question. We compute a new Composite Climate Index (CCI) based on the three Pacific Oscillations to divide the measurement period into positive- (2003 and 2005), negative- (1999 and 2000) and neutral-phase climate years (2001, 2002, 2004, 2006 and 2007). The forest transitioned from an annual net carbon sink (NEP = + 217 g C m{sup -2} year{sup -1}, 1999) to a source (NEP = - 100 g C m{sup -2} year{sup -1}, 2003) during two dominant teleconnection patterns. Net ecosystem productivity (NEP), water use efficiency (WUE) and light use efficiency (LUE) were significantly different (P < 0.01) during positive (NEP = -0.27 g C m{sup -2} day{sup -1}, WUE = 4.1 mg C/g H{sub 2}O, LUE = 0.94 g C MJ{sup -1}) and negative (NEP = +0.37 g C m{sup -2} day{sup -1}, WUE = 3.4 mg C/g H{sub 2}O, LUE = 0.83 g C MJ{sup -1}) climate phases. The CCI was linked to variability in the MODIS Enhanced Vegetation Index (EVI) but not to MODIS Fraction of absorbed Photosynthetically Active Radiation (FPAR). EVI was highest during negative climate phases (1999 and 2000) and was positively correlated with NEP and showed potential for using MODIS to estimate teleconnection-driven anomalies in ecosystem CO{sub 2} exchange in old-growth forests. This work suggests that any increase in the strength or frequency of ENSO coinciding with in-phase, low frequency Pacific oscillations (PDO and PNA) will likely increase

  5. Modelling trends in soil solution concentrations under five forest-soil combinations in the Netherlands

    NARCIS (Netherlands)

    Salm, van der C.; Vries, de W.; Kros, J.

    1996-01-01

    The influence of forest and soil properties on changes in soil solution concentration upon a reduction deposition was examined for five forest-soil combinations with the dynamic RESAM model. Predicted concentrations decreased in the direction Douglas fir - Scotch pine - oak, due to decreased

  6. Breeding birds in riparian and upland dry forests of the Cascade Range

    Science.gov (United States)

    John F. Lehmkuhl; E. Dorsey Burger; Emily K. Drew; John P. Lindsey; Maryellen Haggard; Kent Z. Woodruff

    2007-01-01

    We quantified breeding bird abundance, diversity, and indicator species in riparian and upland dry forests along six third- to fourth-order streams on the east slope of the Cascade Range, Washington, USA. Upland mesic forest on southerly aspects was dominated by open ponderosa pine (Pinus ponderosa) and dry Douglas-fir (Pseudotsuga menziesii...

  7. Seed Dispersal, Microsites or Competition—What Drives Gap Regeneration in an Old-Growth Forest? An Application of Spatial Point Process Modelling

    Directory of Open Access Journals (Sweden)

    Georg Gratzer

    2018-04-01

    Full Text Available The spatial structure of trees is a template for forest dynamics and the outcome of a variety of processes in ecosystems. Identifying the contribution and magnitude of the different drivers is an age-old task in plant ecology. Recently, the modelling of a spatial point process was used to identify factors driving the spatial distribution of trees at stand scales. Processes driving the coexistence of trees, however, frequently unfold within gaps and questions on the role of resource heterogeneity within-gaps have become central issues in community ecology. We tested the applicability of a spatial point process modelling approach for quantifying the effects of seed dispersal, within gap light environment, microsite heterogeneity, and competition on the generation of within gap spatial structure of small tree seedlings in a temperate, old growth, mixed-species forest. By fitting a non-homogeneous Neyman–Scott point process model, we could disentangle the role of seed dispersal from niche partitioning for within gap tree establishment and did not detect seed densities as a factor explaining the clustering of small trees. We found only a very weak indication for partitioning of within gap light among the three species and detected a clear niche segregation of Picea abies (L. Karst. on nurse logs. The other two dominating species, Abies alba Mill. and Fagus sylvatica L., did not show signs of within gap segregation.

  8. Feasibility of high-density climate reconstruction based on Forest Inventory and Analysis (FIA) collected tree-ring data

    Science.gov (United States)

    R. Justin DeRose; Shih-Yu Wang; John D. Shaw

    2013-01-01

    This study introduces a novel tree-ring dataset, with unparalleled spatial density, for use as a climate proxy. Ancillary Douglas fir and pinyon pine tree-ring data collected by the U.S. Forest Service Forest Inventory and Analysis Program (FIA data) were subjected to a series of tests to determine their feasibility as climate proxies. First, temporal coherence between...

  9. Changes to the N cycle following bark beetle outbreaks in two contrasting conifer forest types.

    Science.gov (United States)

    Griffin, Jacob M; Turner, Monica G

    2012-10-01

    Outbreaks of Dendroctonus beetles are causing extensive mortality in conifer forests throughout North America. However, nitrogen (N) cycling impacts among forest types are not well known. We quantified beetle-induced changes in forest structure, soil temperature, and N cycling in Douglas-fir (Pseudotsuga menziesii) forests of Greater Yellowstone (WY, USA), and compared them to published lodgepole pine (Pinus contorta var. latifolia) data. Five undisturbed stands were compared to five beetle-killed stands (4-5 years post-outbreak). We hypothesized greater N cycling responses in Douglas-fir due to higher overall N stocks. Undisturbed Douglas-fir stands had greater litter N pools, soil N, and net N mineralization than lodgepole pine. Several responses to disturbance were similar between forest types, including a pulse of N-enriched litter, doubling of soil N availability, 30-50 % increase in understory cover, and 20 % increase in foliar N concentration of unattacked trees. However, the response of some ecosystem properties notably varied by host forest type. Soil temperature was unaffected in Douglas-fir, but lowered in lodgepole pine. Fresh foliar %N was uncorrelated with net N mineralization in Douglas-fir, but positively correlated in lodgepole pine. Though soil ammonium and nitrate, net N mineralization, and net nitrification all doubled, they remained low in both forest types (mineralization; litter and soil N cycling similarly in each forest type, despite substantial differences in pre-disturbance biogeochemistry. In contrast, soil temperature and soil N-foliar N linkages differed between host forest types. This result suggests that disturbance type may be a better predictor of litter and soil N responses than forest type due to similar disturbance mechanisms and disturbance legacies across both host-beetle systems.

  10. Codominance of Acer saccharum and Fagus grandifolia: the role of Fagus root sprouts along a slope gradient in an old-growth forest.

    Science.gov (United States)

    Takahashi, Koichi; Arii, Ken; Lechowicz, Martin J

    2010-09-01

    We studied how the unusual capacity of mature Fagus grandifolia to form clumps of clonal stems from root sprouts can contribute to its frequent codominance with Acer saccharum in southern Quebec, Canada. In an old-growth forest, the degree of dominance by the two species shifted along topographic gradients spanning a few hundreds of meters, with Fagus more frequent on lower slopes and Acer on upper slopes. The frequency distribution of Fagus stem diameter had an inverse J distribution at all slope positions, which is indicative of continuous recruitment. Acer stem diameter also had an inverse J pattern, except at lower slope positions where size structure was discontinuous. For stems Acer were positively correlated with conspecific canopy trees only on the mid-slope. There were many Fagus seedlings around Acer canopy trees at the lower slope, suggesting the potential replacement of Acer canopy trees by Fagus. This study suggests that the regeneration traits of the two species changed with slope position and that Fagus patches originating from root sprouts can contribute to the maintenance of Acer-Fagus codominance at the scale of local landscapes.

  11. Understanding the long-term fire risks in forests affected by sudden oak death

    Science.gov (United States)

    Yana Valachovic; Chris Lee; Radoslaw Glebocki; Hugh Scanlon; J. Morgan Varner; David. Rizzo

    2010-01-01

    It is assumed that large numbers of dead and down tanoak in forests infested by Phytophthora ramorum contribute to increased fire hazard risk and fuel loading. We studied the impact of P. ramorum infestation on surface fuel loading, potential fire hazard, and potential fire behavior in Douglas-fir- (Pseudotsuga...

  12. Riparian buffer and density management influences on microclimate of young headwater forests of Western Oregon.

    Science.gov (United States)

    Paul D. Anderson; David J. Larson; Samuel S. Chan

    2007-01-01

    Thinning of 30- to 70-year-old Douglas-fir (Psuedotsuga menziesii [Mirb.] Franco) stands is a common silvicultural activity on federal forest lands of the Pacific Northwest, United States. Empirical relationships among riparian functions, silvicultural treatments, and different riparian buffer widths are not well documented for small headwater...

  13. Biomass accumulation rates of Amazonian secondary forest and biomass of old-growth forests from Landsat time series and the Geoscience Laser Altimeter System

    Science.gov (United States)

    E. H. Helmer; M. A. Lefsky; D. A. Roberts

    2009-01-01

    We estimate the age of humid lowland tropical forests in Rondônia, Brazil, from a somewhat densely spaced time series of Landsat images (1975–2003) with an automated procedure, the Threshold Age Mapping Algorithm (TAMA), first described here. We then estimate a landscape-level rate of aboveground woody biomass accumulation of secondary forest by combining forest age...

  14. Invasive scotch broom alters soil chemical properties in Douglas-fir forests of the Pacific Northwest, USA

    Science.gov (United States)

    Robert A. Slesak; Timothy B. Harrington; Anthony W. D′Amato

    2016-01-01

    Backgrounds and aims Scotch broom is an N-fixing invasive species that has high potential to alter soil properties. We compared soil from areas of Scotch broom invasion with nearby areas that had no evidence of invasion to assess the influence of broom on soil P fractions and other chemical properties. Methods The study was...

  15. Temperate and boreal old-growth forests: how do their growth dynamics and biodiversity differ from young stands and managed forests?

    NARCIS (Netherlands)

    Schulze, E.D.; Hessenmoeller, D; Knohl, A.; Luyssaert, S; Boerner, A; Grace, J.

    2009-01-01

    This chapter investigates biomass, net primary productivity (NPP), and net ecosystem productivity (NEP) of boreal and temperate forest ecosystems in relation to stand density and age. Forests may accumulate woody biomass at constant rate for centuries and there is little evidence of an age-related

  16. Effects of forest harvest on stream-water quality and nitrogen cycling in the Caspar Creek watershed

    Science.gov (United States)

    Randy A. Dahlgren

    1998-01-01

    The effects of forest harvest on stream-water quality and nitrogen cycling were examined for a redwood/Douglas-fir ecosystem in the North Fork, Caspar Creek experimental watershed in northern California. Stream-water samples were collected from treated (e.g., clearcut) and reference (e.g., noncut) watersheds, and from various locations downstream from the treated...

  17. Structure and Composition of a Dry Mixed-Conifer Forest in Absence of Contemporary Treatments, Southwest, USA

    Directory of Open Access Journals (Sweden)

    Douglas Cram

    2017-09-01

    Full Text Available Dry mixed-conifer forests in the Southwest occupy an important ecological and hydrological role in upper watersheds. In the absence of reoccurring fire and silvicultural treatments over the last 50 years, we quantified forest structure and composition on prevailing north and south aspects of a dry mixed-conifer forest in southcentral New Mexico using mixed models and ordination analysis in preparation for an experiment in ecological restoration. Results indicated overstory and midstory were dominated by Douglas-fir (Pseudotsuga menziesii and shade tolerant/fire intolerant white fir (Abies concolor with interspersed mature aspen on north aspects, and Douglas-fir and Southwestern white pine (Pinus strobiformis on south aspects. Ponderosa pine (Pinus ponderosa, which was historically co-dominant with Douglas-fir on north and south aspects, was subdominant on south aspects and almost entirely absent on north aspects. Regeneration was dominated by white fir saplings and seedlings on north aspects while ponderosa pine was completely absent. South aspect saplings and seedlings were characterized by Douglas-fir and Southwestern white pine, but almost no ponderosa pine. Ordination analysis characterized the effect of aspect on species composition. Understanding contemporary forest structure and composition is important when planning for desired future conditions that are to be achieved through ecological restoration using silvicultural techniques designed to foster resilience.

  18. First report of Fusarium proliferatum causing Fusarium root disease on sugar pine (Pinus lambertiana) in a forest container nursery in California

    Science.gov (United States)

    J. E. Stewart; K. Otto; G. A. Cline; Kas Dumroese; Ned Klopfenstein; M. -S. Kim

    2016-01-01

    Fusarium species, specifically F. commune, F. proliferatum, and F. solani, can cause severe damping-off and root disease in container and bareroot forest nurseries throughout North America. Many conifer and hardwood species can be affected, but Douglas-fir (Pseudotsuga menziesii), western white pine (Pinus monticola), and ponderosa pine (P. ponderosa) are known to be...

  19. An old-growth forest at the Caspian Sea coast is similar in epiphytic lichens to lowland deciduous forests in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Ismailov, A.; Urbanavichus, G.; Vondrák, Jan; Pouska, V.

    2017-01-01

    Roč. 30, č. 1 (2017), s. 103-125 ISSN 0018-0971 Institutional support: RVO:67985939 Keywords : Dagestan * forest protection * lowland fores indicator Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 0.740, year: 2016

  20. Old growth revisited: integrating social, economic, and ecological perspectives

    Science.gov (United States)

    Marie Oliver; Thomas Spies; Sally.   Duncan

    2009-01-01

    How should old-growth forests be managed? Should they be managed? Stakeholders with differing values and agendas have debated these questions for years. Over time, the debate has evolved: now there is greater awareness about the complexity of old-growth ecosystems and different ways humans value them. A scientist at the Pacific Northwest Research Station has co-edited...

  1. Bat use of remnant old-growth redwood stands

    Science.gov (United States)

    William J. Zielinski; Steven T. Gellman

    1999-01-01

    Most of the old-growth redwood (Sequoia sempervirens) in Calfornia has been cut; regenerating forests will probably never resemble those that were harvested, and what old growth remains on private land occurs in small, isolated remnant patches. The landscapes in which these stands occur differ so markedly from their original condition that their...

  2. Negligible impacts of biomass removal on Douglas-fir growth 29 years after outplanting in the northern Rocky Mountains

    Science.gov (United States)

    Woongsoon Jang; Christopher R. Keyes; Deborah S. Page-Dumroese

    2018-01-01

    To investigate the long-term impacts of biomass harvesting on site productivity, we remeasured trees in the 1974 Forest Residues Utilization Research and Development Program at Coram Experimental Forest in western Montana. Three levels (high, medium, and low) of biomass removal intensity combined with broadcast burning treatment were assigned after clearcut in western...

  3. Selecting Populations for Non-Analogous Climate Conditions Using Universal Response Functions: The Case of Douglas-Fir in Central Europe.

    Science.gov (United States)

    Chakraborty, Debojyoti; Wang, Tongli; Andre, Konrad; Konnert, Monika; Lexer, Manfred J; Matulla, Christoph; Schueler, Silvio

    2015-01-01

    Identifying populations within tree species potentially adapted to future climatic conditions is an important requirement for reforestation and assisted migration programmes. Such populations can be identified either by empirical response functions based on correlations of quantitative traits with climate variables or by climate envelope models that compare the climate of seed sources and potential growing areas. In the present study, we analyzed the intraspecific variation in climate growth response of Douglas-fir planted within the non-analogous climate conditions of Central and continental Europe. With data from 50 common garden trials, we developed Universal Response Functions (URF) for tree height and mean basal area and compared the growth performance of the selected best performing populations with that of populations identified through a climate envelope approach. Climate variables of the trial location were found to be stronger predictors of growth performance than climate variables of the population origin. Although the precipitation regime of the population sources varied strongly none of the precipitation related climate variables of population origin was found to be significant within the models. Overall, the URFs explained more than 88% of variation in growth performance. Populations identified by the URF models originate from western Cascades and coastal areas of Washington and Oregon and show significantly higher growth performance than populations identified by the climate envelope approach under both current and climate change scenarios. The URFs predict decreasing growth performance at low and middle elevations of the case study area, but increasing growth performance on high elevation sites. Our analysis suggests that population recommendations based on empirical approaches should be preferred and population selections by climate envelope models without considering climatic constrains of growth performance should be carefully appraised before

  4. Selecting Populations for Non-Analogous Climate Conditions Using Universal Response Functions: The Case of Douglas-Fir in Central Europe

    Science.gov (United States)

    Chakraborty, Debojyoti; Wang, Tongli; Andre, Konrad; Konnert, Monika; Lexer, Manfred J.; Matulla, Christoph; Schueler, Silvio

    2015-01-01

    Identifying populations within tree species potentially adapted to future climatic conditions is an important requirement for reforestation and assisted migration programmes. Such populations can be identified either by empirical response functions based on correlations of quantitative traits with climate variables or by climate envelope models that compare the climate of seed sources and potential growing areas. In the present study, we analyzed the intraspecific variation in climate growth response of Douglas-fir planted within the non-analogous climate conditions of Central and continental Europe. With data from 50 common garden trials, we developed Universal Response Functions (URF) for tree height and mean basal area and compared the growth performance of the selected best performing populations with that of populations identified through a climate envelope approach. Climate variables of the trial location were found to be stronger predictors of growth performance than climate variables of the population origin. Although the precipitation regime of the population sources varied strongly none of the precipitation related climate variables of population origin was found to be significant within the models. Overall, the URFs explained more than 88% of variation in growth performance. Populations identified by the URF models originate from western Cascades and coastal areas of Washington and Oregon and show significantly higher growth performance than populations identified by the climate envelope approach under both current and climate change scenarios. The URFs predict decreasing growth performance at low and middle elevations of the case study area, but increasing growth performance on high elevation sites. Our analysis suggests that population recommendations based on empirical approaches should be preferred and population selections by climate envelope models without considering climatic constrains of growth performance should be carefully appraised before

  5. Effect of environmental and cultural conditions on medium pH and explant growth performance of Douglas-fir (Pseudotsuga menziesii shoot cultures [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2015-05-01

    Full Text Available The medium pH level of plant tissue cultures has been shown to be essential to many aspects of explant development and growth. Sensitivity or tolerance of medium pH change in vitro varies according to specific requirements of individual species. The objectives of this study are to 1 determine medium pH change over time in storage conditions and with presence of explants, 2 evaluate the effects of medium pH change on explant growth performance and 3 assess the effects of adding a pH stabilizer, 2-(N-morpholinoethanesulfonic acid (MES that is commonly used in Douglas-fir micropropagation medium. Vegetative buds were collected in the spring before breaking dormancy from juvenile and mature donor trees for conducting these evaluations. Medium, with or without MES, was pre-adjusted to five pH levels before adding MES, agar and autoclaving. Medium pH changes and explant growth parameters were measured at eight different incubation times. Overall, MES provided a more stable medium pH, relative to starting pH values, under both light and dark storage conditions as well as with presence of explants. A general trend of decreasing medium pH over time was found comparing explants from juvenile and mature donor genotypes. Explant height and weight growth increased over time, but differ among explants from juvenile and mature donor genotypes. Our findings suggest that a 21-day subculture practice may best sustain medium freshness, medium pH level and desirable explant growth.

  6. Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany

    Czech Academy of Sciences Publication Activity Database

    Vitali, V.; Büntgen, Ulf; Bauhus, J.

    2017-01-01

    Roč. 23, č. 12 (2017), s. 5108-5119 ISSN 1354-1013 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : temperate forest trees * picea-abies karst. * climate- change * water relations * vosges mountains * growth-patterns * species stands * scots pine * alba * productivity * Abies alba * Central Europe * climate change * dendroecology * drought tolerance * forest management * Picea abies * Pseudotsuga menziesii Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  7. Contributions of Ectomycorrhizal Fungal Mats to Forest Soil Carbon Cycles

    Science.gov (United States)

    Kluber, L. A.; Phillips, C. L.; Myrold, D. D.; Bond, B. J.

    2008-12-01

    Ectomycorrhizal (EM) fungi are a prominent and ubiquitous feature of forest soils, forming symbioses with most tree species, yet little is known about the magnitude of their impact on forest carbon cycles. A subset of EM fungi form dense, perennial aggregations of hyphae, which have elevated respiration rates compared with neighboring non-mat soils. These mats are a foci of EM activity and thereby a natural laboratory for examining how EM fungi impact forest soils. In order to constrain the contributions of EM fungi to forest soil respiration, we quantified the proportion of respiration derived from EM mat soils in an old-growth Douglas-fir stand in western Oregon. One dominant genus of mat-forming fungi, Piloderma, covered 56% of the soil surface area. Piloderma mats were monitored for respiration rates over 15 months and found to have on average 10% higher respiration than non-mat soil. At the stand level, this amounts to roughly 6% of soil respiration due to the presence of Piloderma mats. We calculate that these mats may constitute 27% of autotrophic respiration, based on respiration rates from trenched plots in a neighboring forest stand. Furthermore, enzyme activity and microbial community profiles in mat and non-mat soil provide evidence that specialized communities utilizing chitin contribute to this increased efflux. With 60% higher chitinase activity in mats, the breakdown of chitin is likely an important carbon flux while providing carbon and nitrogen to the microbial communities associated with mats. Quantitative PCR showed similar populations of fungi and bacteria in mat and non-mat soils; however, community analysis revealed distinct fungal and bacterial communities in the two soil types. The higher respiration associated with EM mats does not appear to be due only to a proliferation of EM fungi, but to a shift in overall community composition to organisms that efficiently utilize the unique resources available within the mat, including plant and

  8. Cooperative advanced-generation breeding and testing of coastal Douglas-fir and western hemlock—strategy and implementation.

    Science.gov (United States)

    K. J.S. Jayawickrama; G.R. Johnson; T. Ye

    2005-01-01

    As in many temperate regions of the world, forest tree improvement got underway in the Pacific Northwest of the USA in the 1950s, with a number of companies and agencies starting independent tree improvement programs. Booth-Kelly Lumber Co., Crown Zellerbach Corp., the Industrial Forestry Association, Port Blakely Mill Co., Simpson Timber Co., Timber Service Co., the...

  9. Physiology and growth of redwood and Douglas-fir planted after variable density retention outside redwood’s range

    Science.gov (United States)

    Lucy Kerhoulas; Nicholas Kerhoulas; Wade Polda; John-Pascal Berrill

    2017-01-01

    Reforestation following timber harvests is an important topic throughout the coast redwood (Sequoia sempervirens (D. Don) Endl.) range. Furthermore, as drought-induced mortality spreads across many of California’s forests, it is important to understand how physiology and stand structure influence reforestation success. Finally, as climate...

  10. Use of two population metrics clarifies biodiversity dynamics in large-scale monitoring: the case of trees in Japanese old-growth forests: the need for multiple population metrics in large-scale monitoring.

    Science.gov (United States)

    Ogawa, Mifuyu; Yamaura, Yuichi; Abe, Shin; Hoshino, Daisuke; Hoshizaki, Kazuhiko; Iida, Shigeo; Katsuki, Toshio; Masaki, Takashi; Niiyama, Kaoru; Saito, Satoshi; Sakai, Takeshi; Sugita, Hisashi; Tanouchi, Hiroyuki; Amano, Tatsuya; Taki, Hisatomo; Okabe, Kimiko

    2011-07-01

    Many indicators/indices provide information on whether the 2010 biodiversity target of reducing declines in biodiversity have been achieved. The strengths and limitations of the various measures used to assess the success of such measures are now being discussed. Biodiversity dynamics are often evaluated by a single biological population metric, such as the abundance of each species. Here we examined tree population dynamics of 52 families (192 species) at 11 research sites (three vegetation zones) of Japanese old-growth forests using two population metrics: number of stems and basal area. We calculated indices that track the rate of change in all species of tree by taking the geometric mean of changes in population metrics between the 1990s and the 2000s at the national level and at the levels of the vegetation zone and family. We specifically focused on whether indices based on these two metrics behaved similarly. The indices showed that (1) the number of stems declined, whereas basal area did not change at the national level and (2) the degree of change in the indices varied by vegetation zone and family. These results suggest that Japanese old-growth forests have not degraded and may even be developing in some vegetation zones, and indicate that the use of a single population metric (or indicator/index) may be insufficient to precisely understand the state of biodiversity. It is therefore important to incorporate more metrics into monitoring schemes to overcome the risk of misunderstanding or misrepresenting biodiversity dynamics.

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

    Science.gov (United States)

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

    2012-01-01

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

  12. Status and conservation of old-growth forests and endemic birds in the pine-oak zone of the Sierra Madre Occidental, Mexico

    NARCIS (Netherlands)

    Lammertink, J.M.; Rojas-Tomé, J.A.; Casillas-Orona, F.M.; Otto, R.L.

    1996-01-01

    The pine-oak forests of the Sierra Madre Occidental, a mountain range in NW Mexico, have recently been recognized as an area of high endemism and biodiversity. Selective logging threatens three bird species endemic to this habitat, who depend on standing dead trees (snags). This report is based on

  13. Canopy arthropod responses to thinning and burning treatments in old-growth mixed-conifer forest in the Sierra Nevada, California

    Science.gov (United States)

    Thomas Rambo; Timothy Schowalter; Malcolm North

    2014-01-01

    We compared canopy arthropod responses to common fuels reduction treatments at Teakettle Experimental Forest in the south-central Sierra Nevada of California. We sampled arthropod communities among four dominant overstory conifer species and three dominant understory angiosperm species before and after overstory or understory thinning or no thinning treatments followed...

  14. Towards a better understanding of long-term wood-chemistry variations in old-growth forests: A case study on ancient Pinus uncinata trees from the Pyrenees.

    Science.gov (United States)

    Hevia, Andrea; Sánchez-Salguero, Raúl; Camarero, J Julio; Buras, Allan; Sangüesa-Barreda, Gabriel; Galván, J Diego; Gutiérrez, Emilia

    2018-06-01

    Dendrochemical studies in old forests are still underdeveloped. Old trees growing in remote high-elevation areas far from direct human influence constitute a promising biological proxy for the long-term reconstructions of environmental changes using tree-rings. Furthermore, centennial-long chronologies of multi-elemental chemistry at inter- and intra-annual resolution are scarce. Here, we use a novel non-destructive method by applying Micro X-ray fluorescence (μXRF) to wood samples of old Pinus uncinata trees from two Pyrenean high-elevation forests growing on acidic and basic soils. To disentangle ontogenetic (changes in tree age and diameter) from environmental influences (e.g., climate warming) we compared element patterns in sapwood (SW) and heartwood (HW) during the pre-industrial (1700-1849) and industrial (1850-2008) periods. We quantified tree-ring growth, wood density and relative element concentrations at annual (TRW, tree-ring) to seasonal resolution (EW, earlywood; LW, latewood) and related them to climate variables (temperature and precipitation) and volcanic eruptions in the 18th and 19th centuries. We detected differences for most studied elements between SW and HW along the stem and also between EW and LW within rings. Long-term positive and negative trends were observed for Ca and K, respectively. Cl, P and S showed positive trends during the industrial period. However, differences between sites were also notable. Higher values of Mg, Al, Si and the Ca/Mn ratio were observed at the site with acidic soil. Growing-season temperatures were positively related to growth, maximum wood density and to the concentration of most elements. Peaks in S, Fe, Cl, Zn and Ca were linked to major volcanic eruptions (e.g., Tambora in 1815). Our results reveal the potential of long-term wood-chemistry studies based on the μXRF non-destructive technique to reconstruct environmental changes. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Modeling daily gas exchange of a Douglas-fir forest : comparison of three stomatal conductance models with and without a soil water stress function

    NARCIS (Netherlands)

    Wijk, van M.T.; Dekker, S.C.; Bouten, W.; Bosveld, F.C.; Kohsiek, W.; Kramer, K.; Mohren, G.M.J.

    2000-01-01

    Modeling stomatal conductance is a key element in predicting tree growth and water use at the stand scale. We compared three commonly used models of stomatal conductance, the Jarvis-Loustau, Ball-Berry and Leuning models, for their suitability for incorporating soil water stress into their

  16. Cherry Creek Research Natural Area: guidebook supplement 41

    Science.gov (United States)

    Reid Schuller; Jennie Sperling; Tim Rodenkirk

    2011-01-01

    This guidebook describes Cherry Creek Research Natural Area, a 239-ha (590-ac) area that supports old-growth Douglas-fir-western hemlock (Pseudotsuga menziesii- Tsuga heterophylla) forest occurring on sedimentary materials in the southern Oregon Coast Range. Major plant associations present within the area include the western hemlock/Oregon oxalis...

  17. Production rates and costs of cable yarding wood residue from clearcut units

    Science.gov (United States)

    Chris B. LeDoux

    1984-01-01

    Wood residue is a little used source of fiber, chips, and fuel because harvest costs are largely unknown. This study calculates incremental production rates and costs for yarding and loading logging residue in clearcut old-growth Douglas-fir/western hemlock forests. Harvest operations were observed for two timber sales in western Oregon. Three different cable yarding...

  18. Using dendrometer and dendroclimatology data to predict the growth response of Douglas-fir to climate change in the Pacific Northwest, USA

    Science.gov (United States)

    Altered seasonal climate patterns towards hotter, drier summers through the 21st century resulting from global climate change could affect the growth of coniferous forests in the Pacific Northwest (PNW) region of North America. The seasonal effects of temperature, precipitation,...

  19. Tree-ring analysis of the fungal disease Swiss needle cast and its impact on radial growth of Douglas-fir in the Western Oregon coast

    Science.gov (United States)

    To inform an individual-based forest stand model emphasizing belowground competition, we explored the potential of using the relative abundances of ribosomal PCR products from pooled and milled roots, to allocate total root biomass to each of the three coniferous species and to n...

  20. Effects of new export rules, a spotted owl plan, and recession on timber prices and shipments from the Douglas-fir region.

    Science.gov (United States)

    Donald F. Flora; Wendy J. McGInnls

    1992-01-01

    Several recently emplaced and potential Northwest timber policies are causing considerable market turbulence. Estimated were price and volume changes induced by three supply-side policies (a state-log export embargo, forest replanning, and spotted owl reservations) and the demand slide of 1990-91. Impacts were gauged separately and together by using a four-sector model...

  1. Multilocus patterns of nucleotide diversity and divergence reveal positive selection at candidate genes related to cold hardiness in coastal Douglas Fir (Pseudotsuga menziesii var. menziesii).

    Science.gov (United States)

    A. Eckert; J. Wegrzyn; B. Pande; K. Jermstad; J. Lee; J. Liechty; B. Tearse; K. Krutovsky; D. Neale

    2009-01-01

    Forest trees exhibit remarkable adaptations to their environments. The genetic basis for phenotypic adaptation to climatic gradients has been established through a long history of common garden, provenance, and genecological studies. The identities of genes underlying these traits, however, have remained elusive and thus so have the patterns of adaptive molecular...

  2. Managing for Old Growth in Frequent-fire Landscapes

    Directory of Open Access Journals (Sweden)

    Carl E. Fiedler

    2007-12-01

    Full Text Available There is no one-size-fits-all approach to managing frequent-fire, old-growth forests. However, there are general guidelines to follow: 1 set objectives for both structure (tree density, diameter distribution, tree species composition, spatial arrangement, amount of coarse woody debris and function (nutrient cycling, desired tree species regeneration; 2 prioritize treatments according to ecological, economic, and social needs and risks; 3 identify the potential treatments (natural fire, prescribed fire, silvicultural cutting that best meet the objectives and scale of the project; and 4 implement the treatment(s. We discuss each of these guidelines in this article.

  3. Assessing the impact of current and projected climates on Douglas-fir productivity in British Columbia, Canada, using a process-based model (3-PG)

    International Nuclear Information System (INIS)

    Coops, N.C.; Hember, R.A.; Waring, R.H.

    2010-01-01

    Drained peat soils are significant sources of greenhouse gas (GHG) emissions, including nitrous oxide (N 2 O), methane (CH 4 ) and carbon dioxide (CO 2 ), which are produced in the soil and emitted year-round. This study measured N 2 O and CH 4 flux rates and total respiration over a 1-year period from a drained peatland with a grass field subsite and a forested subsite. Annual N 2 O respiration rates for the field were 660 mg per m 2 for the field and 297 mg per m 2 for the forest. Eighty per cent of the annual N 2 O emissions took place in the winter months. Higher emissions were detected during a thaw in April when accumulated N 2 O in the field was released. N 2 O emissions in the forest peaked when the top soil froze in January. Results of the study demonstrated that the timing of episodic high N 2 O emissions differs depending on land use. 52 refs., 1 tab., 6 figs.

  4. Stand conditions immediately following a restoration harvest in an old-growth pine-hardwood remnant

    Science.gov (United States)

    D. C. Bragg

    2010-01-01

    Portions of the Levi Wilcoxon Demonstration Forest (LWDF), a privately owned parcel of old-growth pine and hardwoods in Ashley County, Arkansas, were recently treated to restore conditions similar to some historic accounts of the virgin forest. Following a hardwood-only cut, a post-harvest inventory showed that the number of tree species in the sample area declined...

  5. Restoring old-growth southern pine ecosystems: strategic lessons from long-term silvicultural research

    Science.gov (United States)

    Don C. Bragg; Michael G. Shelton; James M. Guldin

    2008-01-01

    The successful restoration of old-growth-like loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated forests requires the integration of ecological information with long-term silvicultural research from places such as the Crossett Experimental Forest (CEF). Conventional management practices such as timber harvesting or competition control have supplied...

  6. Natural seedlings and sprouts after regeneration cuttings in old-growth redwood

    Science.gov (United States)

    Kenneth N. Boe

    1975-01-01

    Natural regeneration of harvested old-growth stands of redwood (Sequoia sempervirens) is one way to start a new forest that is needed quickly for continuous timber production. Natural seedlings and sprouts developing after stands were cut were studied on the Redwood Experimental Forest, northern California. Three types of regeneration cuttings were...

  7. Observations of the scale-dependent turbulence and evaluation of the flux–gradient relationship for sensible heat for a closed Douglas-fir canopy in very weak wind conditions

    Directory of Open Access Journals (Sweden)

    D. Vickers

    2014-09-01

    Full Text Available Observations of the scale-dependent turbulent fluxes, variances, and the bulk transfer parameterization for sensible heat above, within, and beneath a tall closed Douglas-fir canopy in very weak winds are examined. The daytime sub-canopy vertical velocity spectra exhibit a double-peak structure with peaks at timescales of 0.8 s and 51.2 s. A double-peak structure is also observed in the daytime sub-canopy heat flux co-spectra. The daytime momentum flux co-spectra in the upper bole space and in the sub-canopy are characterized by a relatively large cross-wind component, likely due to the extremely light and variable winds, such that the definition of a mean wind direction, and subsequent partitioning of the momentum flux into along- and cross-wind components, has little physical meaning. Positive values of both momentum flux components in the sub-canopy contribute to upward transfer of momentum, consistent with the observed sub-canopy secondary wind speed maximum. For the smallest resolved scales in the canopy at nighttime, we find increasing vertical velocity variance with decreasing timescale, consistent with very small eddies possibly generated by wake shedding from the canopy elements that transport momentum, but not heat. Unusually large values of the velocity aspect ratio within the canopy were observed, consistent with enhanced suppression of the horizontal wind components compared to the vertical by the very dense canopy. The flux–gradient approach for sensible heat flux is found to be valid for the sub-canopy and above-canopy layers when considered separately in spite of the very small fluxes on the order of a few W m−2 in the sub-canopy. However, single-source approaches that ignore the canopy fail because they make the heat flux appear to be counter-gradient when in fact it is aligned with the local temperature gradient in both the sub-canopy and above-canopy layers. While sub-canopy Stanton numbers agreed well with values

  8. Thinning, tree-growth, and resistance to multi-year drought in a mixed-conifer forest of northern California

    Science.gov (United States)

    Vernon, Michael J.; Sherriff, Rosemary L.; van Mantgem, Phillip; Kane, Jeffrey M.

    2018-01-01

    Drought is an important stressor in forest ecosystems that can influence tree vigor and survival. In the U.S., forest managers use two primary management techniques to promote resistance and resilience to drought: prescribed fire and mechanical thinning. Generally applied to reduce fuels and fire hazard, treatments may also reduce competition for resources that may improve tree-growth and reduce mortality during drought. A recent severe and prolonged drought in California provided a natural experiment to investigate tree-growth responses to fuel treatments and climatic stress. We assessed tree-growth from 299 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) in treated and untreated stands during severe drought from 2012 to 2015 in the mixed-conifer forests of Whiskeytown National Recreation Area (WNRA) in northern California. The treatment implemented at WNRA removed 34% of live basal area through mechanical thinning with a subsequent pile burning of residual fuels. Tree-growth was positively associated with crown ratio and negatively associated with competition and a 1-year lag of climate water deficit, an index of drought. Douglas-fir generally had higher annual growth than ponderosa pine, although factors affecting growth were the same for both species. Drought resistance, expressed as the ratio between mean growth during drought and mean growth pre-drought, was higher in treated stands compared to untreated stands during both years of severe drought (2014 and 2015) for ponderosa pine but only one year (2014) for Douglas-fir. Thinning improved drought resistance, but tree size, competition and species influenced this response. On-going thinning treatments focused on fuels and fire hazard reduction are likely to be effective at promoting growth and greater drought resistance in dry mixed-conifer forests. Given the likelihood of future droughts, land managers may choose to implement similar treatments to reduce potential impacts.

  9. Structural attributes of two old-growth Cross Timbers stands in western Arkansas

    Science.gov (United States)

    Don C. Bragg; David W. Stahle; K. Chris Cerny

    2012-01-01

    Comprised of largely non-commercial, xeric, oak-dominated forests, the Cross Timbers in Arkansas have been heavily altered over the last two centuries, and thus only scattered parcels of old-growth timber remain. We inventoried and mapped two such stands on Fort Chaffee Military Training Center in Sebastian County, Arkansas. The west-facing Christmas Knob site is...

  10. Interactions between leaf nitrogen status and longevity in relation to N cycling in three contrasting European forest canopies

    Directory of Open Access Journals (Sweden)

    L. Wang

    2013-02-01

    Full Text Available Seasonal and spatial variations in foliar nitrogen (N parameters were investigated in three European forests with different tree species, viz. beech (Fagus sylvatica L., Douglas fir (Pseudotsuga menziesii (Mirb. Franco and Scots pine (Pinus sylvestris L. growing in Denmark, the Netherlands and Finland, respectively. The objectives were to investigate the distribution of N pools within the canopies of the different forests and to relate this distribution to factors and plant strategies controlling leaf development throughout the seasonal course of a vegetation period. Leaf N pools generally showed much higher seasonal and vertical variability in beech than in the coniferous canopies. However, also the two coniferous tree species behaved very differently with respect to peak summer canopy N content and N re-translocation efficiency, showing that generalisations on tree internal vs. ecosystem internal N cycling cannot be made on the basis of the leaf duration alone. During phases of intensive N turnover in spring and autumn, the NH4+ concentration in beech leaves rose considerably, while fully developed green beech leaves had relatively low tissue NH4+, similar to the steadily low levels in Douglas fir and, particularly, in Scots pine. The ratio between bulk foliar concentrations of NH4+ and H+, which is an indicator of the NH3 emission potential, reflected differences in foliage N concentration, with beech having the highest values followed by Douglas fir and Scots pine. Irrespectively of the leaf habit, i.e. deciduous versus evergreen, the majority of the canopy foliage N was retained within the trees. This was accomplished through an effective N re-translocation (beech, higher foliage longevity (fir or both (boreal pine forest. In combination with data from a literature review, a general relationship of decreasing N re

  11. Calibrating and testing a gap model for simulating forest management in the Oregon Coast Range

    Science.gov (United States)

    Pabst, R.J.; Goslin, M.N.; Garman, S.L.; Spies, T.A.

    2008-01-01

    The complex mix of economic and ecological objectives facing today's forest managers necessitates the development of growth models with a capacity for simulating a wide range of forest conditions while producing outputs useful for economic analyses. We calibrated the gap model ZELIG to simulate stand-level forest development in the Oregon Coast Range as part of a landscape-scale assessment of different forest management strategies. Our goal was to incorporate the predictive ability of an empirical model with the flexibility of a forest succession model. We emphasized the development of commercial-aged stands of Douglas-fir, the dominant tree species in the study area and primary source of timber. In addition, we judged that the ecological approach of ZELIG would be robust to the variety of other forest conditions and practices encountered in the Coast Range, including mixed-species stands, small-scale gap formation, innovative silvicultural methods, and reserve areas where forests grow unmanaged for long periods of time. We parameterized the model to distinguish forest development among two ecoregions, three forest types and two site productivity classes using three data sources: chronosequences of forest inventory data, long-term research data, and simulations from an empirical growth-and-yield model. The calibrated model was tested with independent, long-term measurements from 11 Douglas-fir plots (6 unthinned, 5 thinned), 3 spruce-hemlock plots, and 1 red alder plot. ZELIG closely approximated developmental trajectories of basal area and large trees in the Douglas-fir plots. Differences between simulated and observed conifer basal area for these plots ranged from -2.6 to 2.4 m2/ha; differences in the number of trees/ha ???50 cm dbh ranged from -8.8 to 7.3 tph. Achieving these results required the use of a diameter-growth multiplier, suggesting some underlying constraints on tree growth such as the temperature response function. ZELIG also tended to overestimate

  12. Fluxes of CO2, CH4, CO, BVOCs, NOx, and O3 in an Old Growth Amazonian Forest: Ecosystem Processes, Carbon Cycle, Atmospheric Chemistry, and Feedbacks on Climate

    Energy Technology Data Exchange (ETDEWEB)

    Wofsy, Steven C. [Harvard Univ., Cambridge, MA (United States)

    2016-12-20

    A comprehensive, merged data set of trace gases (NO, NO2, CO2, CH4 and O3) along with has been tabulated and subjected to meticulous quality assurance and quality control (QA/QC). The merged data set is being submitted to the ARM website dedicated to the Green Ocean Experiment: https://www.arm.gov/research/campaigns/amf2014goamazon Analysis using the final data set is in progress to determine the magnitudes of the fluxes for CH4, H2O, CO2, O3, NOx, sensible and latent heat, momentum, and their seasonal variations. Here are summary statements, from the discussion above: Total NO fluxes were calculated following Keller et al., 1986. A vertical gradient is established in the mixing ratio of NO because it is emitted at the soil surface and mixed upward in the atmosphere (see above). Once in the atmosphere, the NO reacts rapidly with O3 to produce NO2 (NO + O3 → NO2 + O2). Therefore, if the vertical profiles of the mixing ratios of NO and O3 are known, the surface flux of NO may be determined. If any other reaction removes NO (e.g., deposition on leaves), FNO should estimate the lower limit to the NO flux from the soil in this forest. Our preliminary results show fluxes of NO averaged 133 x 109 molecules cm-2 s-1, a factor of 4 higher than fluxes previously observed in white sand soils in the Amazon, and a factor of 3 to 14 higher than fluxes observed for yellow clay soils (Bakwin et al., 1990 and references therein). The soil in the km 67 site is predominately oxisol with pockets of sandy ultisols, both having low reduced nutrient contents, mostly due to efficient microorganism decomposition and acid leaching by rain water. Oxisols contain both oxidized and reduced forms of nitrogen, of which concentrations vary independently of leaching (Jordan et al., 1982), with most

  13. Convergence of the effect of root hydraulic functioning and root hydraulic redistribution on ecosystem water and carbon balance across divergent forest ecosystems

    Science.gov (United States)

    domec, J.; King, J. S.; Ogée, J.; Noormets, A.; Warren, J.; Meinzer, F. C.; Sun, G.; Jordan-Meille, L.; Martineau, E.; Brooks, R. J.; Laclau, J.; Battie Laclau, P.; McNulty, S.

    2012-12-01

    INVITED ABSTRACT: Deep root water uptake and hydraulic redistribution (HR) play a major role in forest ecosystems during drought, but little is known about the impact of climate change on root-zone processes influencing HR and its consequences on water and carbon fluxes. Using data from two old growth sites in the western USA, two mature sites in the eastern USA, one site in southern Brazil, and simulations with the process-based model MuSICA, our objectives were to show that HR can 1) mitigate the effects of soil drying on root functioning, and 2) have important implications for carbon uptake and net ecosystem exchange (NEE). In a dry, old-growth ponderosa pine (USA) and a eucalyptus stand (Brazil) both characterized by deep sandy soils, HR limited the decline in root hydraulic conductivity and increased dry season tree transpiration (T) by up to 30%, which impacted NEE through major increases in gross primary productivity (GPP). The presence of deep-rooted trees did not necessarily imply high rates of HR unless soil texture allowed large water potential gradients to occur, as was the case in the wet old-growth Douglas-fir/mixed conifer stand. At the Duke mixed hardwood forest characterized by a shallow clay-loam soil, modeled HR was low but not negligible, representing annually up to 10% of T, and maintaining root conductance high. At this site, in the absence of HR, it was predicted that annual GPP would have been diminished by 7-19%. At the coastal loblolly pine plantation, characterized by deep organic soil, HR limited the decline in shallow root conductivity by more than 50% and increased dry season T by up to 40%, which increased net carbon gain by the ecosystem by about 400 gC m-2 yr-1, demonstrating the significance of HR in maintaining the stomatal conductance and assimilation capacity of the whole ecosystem. Under future climate conditions (elevated atmospheric [CO2] and temperature), HR is predicted to be reduced by up to 50%; reducing the resilience of

  14. Structural Equation Modeling: Theory and Applications in Forest Management

    Directory of Open Access Journals (Sweden)

    Tzeng Yih Lam

    2012-01-01

    Full Text Available Forest ecosystem dynamics are driven by a complex array of simultaneous cause-and-effect relationships. Understanding this complex web requires specialized analytical techniques such as Structural Equation Modeling (SEM. The SEM framework and implementation steps are outlined in this study, and we then demonstrate the technique by application to overstory-understory relationships in mature Douglas-fir forests in the northwestern USA. A SEM model was formulated with (1 a path model representing the effects of successively higher layers of vegetation on late-seral herbs through processes such as light attenuation and (2 a measurement model accounting for measurement errors. The fitted SEM model suggested a direct negative effect of light attenuation on late-seral herbs cover but a direct positive effect of northern aspect. Moreover, many processes have indirect effects mediated through midstory vegetation. SEM is recommended as a forest management tool for designing silvicultural treatments and systems for attaining complex arrays of management objectives.

  15. Final Progress Report on Model-Based Diagnosis of Soil Limitations to Forest Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Luxmoore, R.J.

    2004-08-30

    This project was undertaken in support of the forest industry to link modeling of nutrients and productivity with field research to identify methods for enhancing soil quality and forest productivity and for alleviating soil limitations to sustainable forest productivity. The project consisted of a series of related tasks, including (1) simulation of changes in biomass and soil carbon with nitrogen fertilization, (2) development of spreadsheet modeling tools for soil nutrient availability and tree nutrient requirements, (3) additional modeling studies, and (4) evaluation of factors involved in the establishment and productivity of southern pine plantations in seasonally wet soils. This report also describes the two Web sites that were developed from the research to assist forest managers with nutrient management of Douglas-fir and loblolly pine plantations.

  16. Coniferous tree plantations in forest conditions-economic analysis of dedicated and semi-dedicated pathways to increase wood production

    International Nuclear Information System (INIS)

    Rakotoarison, Hanitra; Richter, Claudine; Cailly, Priscilla; Deleuze, Christine; Berthelot, Alain

    2015-01-01

    To meet growing demand for wood, particularly softwoods, the authors study a number of new silvicultural pathways for planting 3 species: Douglas fir, spruce and maritime pine. The goal of these pathways is to achieve specialised production of either industrial and workable timber, or a mixture of industrial and workable timber with medium-diameter workable timber. Pathways of this type have already been standardised for hardwoods, generally on fertile farmland. In a less fertile forest context, softwoods have a significant potential for woody production but specialized pathways and their profitability have yet to be studied. This article describes the innovative work being done to construct and simulate profitable production, new potential pathways, where plantation density, rotation time, the level of fertility are made to vary using the data from the FCBA test network in conjunction with the FCBA growth models (Oasis for spruce and Douglas fir, Sylveco for maritime pine). Economic data is derived from auction sales statistics and the ONF management and forestry work costs for the period 2012-2015. The Economics module developed by FCBA and ONF on the Capsis platform in the framework of the ICI project (Futurol) was used for the economic simulations. The analyses show that compared to conventional pathways, these pathways generally increase productivity but are nonetheless less profitable than current economic assumptions, although results vary according to species, fertility and the particular pathway. The sensitivity study shows that variations in the price of wood could alter the performance ratings as between conventional and specialised pathways. (authors)

  17. Climate Drives Episodic Conifer Establishment after Fire in Dry Ponderosa Pine Forests of the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    Monica T. Rother

    2017-05-01

    Full Text Available In recent years, warming climate and increased fire activity have raised concern about post-fire recovery of western U.S. forests. We assessed relationships between climate variability and tree establishment after fire in dry ponderosa pine forests of the Colorado Front Range. We harvested and aged over 400 post-fire juvenile ponderosa pine (Pinus ponderosa and Douglas-fir (Pseudotsuga menziesii trees using an improved tree-ring based approach that yielded annually-resolved dates and then assessed relationships between climate variability and pulses of tree establishment. We found that tree establishment was largely concentrated in years of above-average moisture availability in the growing season, including higher amounts of precipitation and more positive values of the Palmer Drought Severity Index. Under continued climate change, drier conditions associated with warming temperatures may limit forest recovery after fire, which could result in lower stand densities or shifts to non-forested vegetation in some areas.

  18. Development of silvicultural systems for maintaining old-growth conditions in the temperate rainforest of southeast Alaska.

    Science.gov (United States)

    Michael H. McClellan

    2004-01-01

    In the old-growth temperate rainforests of southeast Alaska, concerns over clearcutting effects on habitat, visual quality, slope stability, and biodiversity have created a demand for the use of other silvicultural systems. The forest vegetation and animal taxa of southeast Alaska appear to be well adapted to frequent, widespread, small-scale disturbance, suggesting...

  19. Analysis of conifer forest regeneration using Landsat Thematic Mapper data

    Science.gov (United States)

    Fiorella, Maria; Ripple, William J.

    1995-01-01

    Landsat Thematic Mapper (TM) data were used to evaluate young conifer stands in the western Cascade Mountains of Oregon. Regression and correlation analyses were used to describe the relationships between TM band values and age of young Douglas-fir stands (2 to 35 years old). Spectral data from well regenerated Douglas-fir stands were compared to those of poorly regenerated conifer stands. TM bands 1, 2, 3, 5, 6, and 7 were inversely correlated with the age (r greater than or equal to -0.80) of well regenerated Douglas-fir stands. Overall, the 'structural index' (TM 4/5 ratio) had the highest correlation to age of Douglas-fir stands (r = 0.96). Poorly regenerated stands were spectrally distinct from well regenerated Douglas-fir stands after the stands reached an age of approximately 15 years.

  20. Structural and compositional controls on transpiration in 40- and 450-year-old riparian forests in western Oregon, USA.

    Science.gov (United States)

    Moore, Georgianne W; Bond, Barbara J; Jones, Julia A; Phillips, Nathan; Meinzer, Federick C

    2004-05-01

    Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in similar environments, or are there other structural or compositional components in the forests that compensate for tree-level differences? We investigated the impacts of tree age, species composition and sapwood basal area on stand-level transpiration in adjacent watersheds at the H.J. Andrews Forest in the western Cascades of Oregon, one containing a young, mature (about 40 years since disturbance) conifer forest and the other an old growth (about 450 years since disturbance) forest. Sap flow measurements were used to evaluate the degree to which differences in age and species composition affect water use. Stand sapwood basal area was evaluated based on a vegetation survey for species, basal area and sapwood basal area in the riparian area of two watersheds. A simple scaling exercise derived from estimated differences in water use as a result of differences in age, species composition and stand sapwood area was used to estimate transpiration from late June through October within the entire riparian area of these watersheds. Transpiration was higher in the young stand because of greater sap flux density (sap flow per unit sapwood area) by age class and species, and greater total stand sapwood area. During the measurement period, mean daily sap flux density was 2.30 times higher in young compared with old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Sap flux density was 1.41 times higher in young red alder (Alnus rubra Bong.) compared with young P. menziesii trees, and was 1.45 times higher in old P. menziesii compared with old western hemlock (Tsuga heterophylla (Raf

  1. Litterfall, litter decomposition and nitrogen mineralization in old-growth evergreen and secondary deciduous Nothofagus forests in south-central Chile Aporte, descomposición de hojarasca y mineralización de nitrógeno en bosques siempreverdes de antiguo crecimiento y bosques secundarios deciduos, centro-sur de Chile

    Directory of Open Access Journals (Sweden)

    JEROEN STAELENS

    2011-03-01

    Full Text Available South Chilean forest ecosystems represent one of the largest areas of old-growth temperate rainforests remaining in the Southern hemisphere and have a high ecological value, but suffer from deforestation, invasion by exotic species, fragmentation, and increasing atmospheric nitrogen (N deposition. To support sustainable forest management, more knowledge is required on nutrient cycling of these ecosystems. Therefore, a descriptive study of nutrient dynamics was done in four Valdivian rainforests in the lower Andes range of south Chile: old-growth and altered evergreen stands and unmanaged and managed secondary deciduous stands. Time series were measured for (i mass (four year and nutrient content (N, K, Ca, and Mg; one year of litterfall, (ii decomposition and nutrient dynamics (N, C, K, Ca, Mg, and P; one year of leaf litter and Saxegothaea conspicua bark litter, and (iii in situ topsoil net N mineralization (one year. Litterfall in the four stands ranged from 3.5 to 5.8 ton ha-1 yr-1, was temporarily lower in the managed than in the unmanaged deciduous stand and had a different seasonality in the evergreen stands than in the deciduous stands. Leaf litter decomposed faster (on average 32 % mass loss after one year than bark litter (8 % but without significant differences between leaf litter types. Net N in evergreen leaf litter decreased during decomposition but increased in deciduous leaf litter. Net soil N mineralization was fastest in the pristine evergreen stand, intermediate in the deciduous stands and slowest in the altered evergreen forest. Given the absence of replicated stands, the definite impact of forest type or management regime on the internal nutrient cycling cannot be demonstrated. Nevertheless, the results suggest that management can affect nutrient turnover by altering species composition and forest structure, while recent (five years selective logging in secondary deciduous forest did not affect litter decomposition or N

  2. Forest health in Canada, Montane cordillera ecozone 2003

    Energy Technology Data Exchange (ETDEWEB)

    Allen, E.; Garbutt, R.; Hirvonen, H.; Pinnell, H.

    2004-07-01

    This paper describes the key forest health issues affecting the 6 main forest types in Canada's Montane Cordillera ecozone in the central interior of British Columbia and the Alberta Foothills. In order to protect and conserve biological diversity, the Canadian Council of Forest Ministers adopted national criteria to measure sustainable forest management. This report describes the Montane Cordillera landscape conditions, pre-industrial ecological influences, current ecological influences, and the impact of invasive alien insects and diseases on the diversity of tree species. Pine forests in the Montane Cordillera ecozone are threatened by the mountain pine beetle. Fire suppression has also resulted in ecological changes to forests in the Montane Cordillera, including an increase in Douglas-firs, gradual replacement of Lodgepole pine forests, and reduced health of Ponderosa pine ecosystems. Alien insects are being monitored by provincial forestry agencies through annual surveys. They are also being controlled through localized treatment programs. The impact of land use practices such as forest harvesting on forest structure and composition was also addressed. It was noted that the unrestricted movement of wood and forestry products also increases the threat of invasive alien diseases and insects. The trees in this ecozone have not been damaged by air pollution. refs., tabs., figs.

  3. Late-successional forests and northern spotted owls: how effective is the Northwest Forest Plan?

    Science.gov (United States)

    Miles Hemstrom; Martin G. Raphael

    2000-01-01

    This paper describes the late-successional and old-growth forest and the northern spotted owl effectiveness monitoring plans for the Northwest Forest Plan. The effectiveness monitoring plan for late-successional and old-growth forests will track changes in forest spatial distribution, and within-stand structure and composition, and it will predict future trends.

  4. Stress wave nondestructive evaluation of Douglas-fir peeler cores

    Science.gov (United States)

    Robert J. Ross; John I. Zerbe; Xiping Wang; David W. Green; Roy F. Pellerin

    2005-01-01

    With the need for evaluating the utilization of veneer peeler log cores in higher value products and the increasing importance of utilizing round timbers in poles, posts, stakes, and building construction components, we conducted a cooperative project to verify the suitability of stress wave nondestructive evaluation techniques for assessing peeler cores and some...

  5. Forest Structure Affects Soil Mercury Losses in the Presence and Absence of Wildfire.

    Science.gov (United States)

    Homann, Peter S; Darbyshire, Robyn L; Bormann, Bernard T; Morrissette, Brett A

    2015-11-03

    Soil is an important, dynamic component of regional and global mercury (Hg) cycles. This study evaluated how changes in forest soil Hg masses caused by atmospheric deposition and wildfire are affected by forest structure. Pre and postfire soil Hg measurements were made over two decades on replicate experimental units of three prefire forest structures (mature unthinned, mature thinned, clear-cut) in Douglas-fir dominated forest of southwestern Oregon. In the absence of wildfire, O-horizon Hg decreased by 60% during the 14 years after clearcutting, possibly the result of decreased atmospheric deposition due to the smaller-stature vegetative canopy; in contrast, no change was observed in mature unthinned and thinned forest. Wildfire decreased O-horizon Hg by >88% across all forest structures and decreased mineral-soil (0 to 66 mm depth) Hg by 50% in thinned forest and clear-cut. The wildfire-associated soil Hg loss was positively related to the amount of surface fine wood that burned during the fire, the proportion of area that burned at >700 °C, fire severity as indicated by tree mortality, and soil C loss. Loss of soil Hg due to the 200,000 ha wildfire was more than four times the annual atmospheric Hg emissions from human activities in Oregon.

  6. Regeneration after cutting of old-growth northern hardwoods in New Hampshire

    Science.gov (United States)

    William B. Leak; Robert W., Jr. Wilson

    1958-01-01

    Past experience with cuttings in old-growth northern hardwoods has demonstrated that the primary regeneration problem is to obtain a large proportion of desirable species of good quality. Regardless of method or intensity of cutting, the total amount of reproduction usually is adequate. Second-growth stands are a different story: this report pertains only to old-growth...

  7. Lidar-derived canopy architecture predicts Brown Creeper occupancy of two western coniferous forests

    Science.gov (United States)

    Jody C. Vogeler; Andrew T. Hudak; Lee A. Vierling; Kerri T. Vierling

    2013-01-01

    In western conifer-dominated forests where the abundance of old-growth stands is decreasing, species such as the Brown Creeper (Certhia americana) may be useful as indicator species for monitoring the health of old-growth systems because they are strongly associated with habitat characteristics associated with old growth and are especially sensitive to forest...

  8. Latent resilience in ponderosa pine forest: effects of resumed frequent fire.

    Science.gov (United States)

    Larson, Andrew J; Belote, R Travis; Cansler, C Alina; Parks, Sean A; Dietz, Matthew S

    2013-09-01

    Ecological systems often exhibit resilient states that are maintained through negative feedbacks. In ponderosa pine forests, fire historically represented the negative feedback mechanism that maintained ecosystem resilience; fire exclusion reduced that resilience, predisposing the transition to an alternative ecosystem state upon reintroduction of fire. We evaluated the effects of reintroduced frequent wildfire in unlogged, fire-excluded, ponderosa pine forest in the Bob Marshall Wilderness, Montana, USA. Initial reintroduction of fire in 2003 reduced tree density and consumed surface fuels, but also stimulated establishment of a dense cohort of lodgepole pine, maintaining a trajectory toward an alternative state. Resumption of a frequent fire regime by a second fire in 2011 restored a low-density forest dominated by large-diameter ponderosa pine by eliminating many regenerating lodgepole pines and by continuing to remove surface fuels and small-diameter lodgepole pine and Douglas-fir that established during the fire suppression era. Our data demonstrate that some unlogged, fire-excluded, ponderosa pine forests possess latent resilience to reintroduced fire. A passive model of simply allowing lightning-ignited fires to burn appears to be a viable approach to restoration of such forests.

  9. What causes the density effect in young forest plantations?; FINAL

    International Nuclear Information System (INIS)

    Barbara J. Bond; Gary A. Ritchie

    2002-01-01

    In young forest plantations, trees planted at high densities frequently show more rapid height and diameter growth than those plants at lower densities. This positive growth response to density (the ''density effect'') often manifests long before seedlings are tall enough to shade one another, so it is not a simple response to shade. The mechanism(s) which trigger and sustain this growth enhancement are unknown. Our objectives were to document the temporal dynamics of positive growth response to increasing density in Douglas-fir plantations and to test two hypotheses as potential mechanisms for this response. The hypotheses are (1) a canopy boundary layer effect, and (2) alterations in the quality of light reflected from neighboring trees. The ''boundary layer'' hypotheses proposes that changes in atmospheric mixing occur in high-density plantations, promoting increased concentrations of CO(sub 2) and H(sub 2)O vapor during early morning hours, which in turn would enhance carbon assimilation. The ''light quality'' hypothesis proposes that the presence of neighbors alters the ratio of red to far red light in the canopy environment. Plant sensors detect this change in light quality, and growth and development is altered in response. We found that boundary layer conductance was higher, as we predicted, in low-density Douglas-fir stands than in high-density stands five years after planting. The changes in boundary conductance were accompanied by higher CO(sub 2) and H(sub 2)O vapor during early morning hours. However, we also found that the primary manifestation of the density effect in Douglas-fir occurs two to four years after planting, and we were not able to measure differences in boundary conductance in different densities at that time. Also, we found no difference in carbon isotope composition of wood cellulose formed in high- vs. low-density stands two to three years after planting. We conclude that although stand density may have a significant impact on

  10. Chapter 36: Status of Forest Habitat of the Marbled Murrelet

    Science.gov (United States)

    David A. Perry

    1995-01-01

    Marbled Murrelets (Brachyramphus marmoratus) have been shown to be dependant upon old-growth forests for nesting habitat. These forests have declined over the last century as they are cut for human use. This paper reviews the current status of old-growth forests along the west coast, in both the United States and Canada.

  11. Old Growth Conifer Watersheds in the Western Cascades, Oregon: Sentinels of Climate Change

    Science.gov (United States)

    Miles, K. M.

    2011-12-01

    In the Pacific Northwest, where the majority of precipitation falls during the winter, mountain snowpacks provide an important source of streamflow during the dry summer months when water demands are frequently highest. Increasing temperatures associated with climate change are expected to result in a decline in winter snowpacks in western North America, earlier snowmelt, and subsequently a shift in the timing of streamflows, with an increasing fraction of streamflows occurring earlier in the water year and drier conditions during the summer. Long-term records from headwater watersheds in old growth conifer forest at the H. J. Andrews Experimental Forest (HJ Andrews), Oregon, provide the opportunity to examine changes in climate, vegetation, and streamflow. Continuous streamflow records have been collected since 1953, 1964, and 1969 from three small (8.5-60 ha) watersheds (WS2, WS8, and WS9). Over the 40- to 50-year period of study, late winter to early summer monthly average minimum temperatures have increased by 1-2°C, and spring snow water equivalent at a nearby Snotel site has declined, but monthly precipitation has remained unchanged. Spring runoff ratios have declined in by amounts equivalent to 0.59-2.45 mm day-1 at WS2, WS8, and WS9, which are comparable to estimated rates of stand-level transpiration from trees in these watersheds. However, winter runoff ratios have not changed significantly at either WS2 or WS9, and have actually decreased at WS8 by 2.43 mm day-1 over the period of record. Furthermore, summer runoff ratios have not changed significantly at either WS8 or WS9, and have increased at WS2 by 0.34 mm day-1 over the period of record. These findings suggest that warming temperatures have resulted in a reduction in spring snowpacks and an earlier onset of evapotranspiration in the spring when soil moisture is abundant, but physiological responses of these conifer forests to water stress and water surplus may mitigate or exceed the expression of a

  12. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Directory of Open Access Journals (Sweden)

    Brad Seely

    Full Text Available Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine for established stands due to increased moisture stress mortality.

  13. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Science.gov (United States)

    Seely, Brad; Welham, Clive; Scoullar, Kim

    2015-01-01

    Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality.

  14. Charcoal and Total Carbon in Soils from Foothills Shrublands to Subalpine Forests in the Colorado Front Range

    Directory of Open Access Journals (Sweden)

    Robert Sanford

    2012-10-01

    Full Text Available Temperate conifer forests in the Colorado Front Range are fire-adapted ecosystems where wildland fires leave a legacy in the form of char and charcoal. Long-term soil charcoal C (CC pools result from the combined effects of wildland fires, aboveground biomass characteristics and soil transfer mechanisms. We measured CC pools in surface soils (0–10 cm at mid-slope positions on east facing aspects in five continuous foothills shrubland and conifer forest types. We found a significant statistical effect of vegetation type on CC pools along this ecological gradient, but not a linear pattern increasing with elevation gain. There is a weak bimodal pattern of CC gain with elevation between foothills shrublands (1.2 mg CC ha−1 and the lower montane, ponderosa pine (1.5 mg CC ha−1 and Douglas-fir (1.5 mg CC ha−1 forest types prior to a mid-elevation decline in upper montane lodgepole pine forests (1.2 mg CC ha−1 before increasing again in the spruce/subalpine fir forests (1.5 mg CC ha−1. We propose that CC forms and accumulates via unique ecological conditions such as fire regime. The range of soil CC amounts and ratios of CC to total SOC are comparable to but lower than other regional estimates.

  15. Forest Fire Smoldering Emissions from Ponderosa Pine Duff in Central Washington

    Science.gov (United States)

    Baker, S. P.; Lincoln, E.; Page, W.; Richardson, M.

    2017-12-01

    Forest fire smoldering combustion is a significant contribution to pollution and carbon emissions. Smoldering combustion produces the majority of carbon monoxide (CO), methane (CH4), volatile organic compounds (VOC), and fine particulate matter (PM2.5) emitted by forest fires when it occurs. The emission factor for PM2.5 and many VOCs are correlated with the modified combustion efficiency (MCE), which is the ratio of CO2 emitted, to the sum of emitted CO2 and CO. MCE is a measure of the relative ratio of flaming and smoldering combustion, but its relationship to the physical fire process is poorly studied. We measured carbon emission rates and individual emission factors for CO, CO2, CH4, and VOC's from smoldering combustion on Ponderosa pine /Douglas-Fir forest sites in central Washington. The emission factor results are linked with concurrent thermal measurements made at various depths in the duff and surface IR camera imagery. The MCE value ranged from .80 to .91 and are correlated with emission factors for 24 carbon compounds. Other data collected were fuel moistures and duff temperatures at depth increments. This goal of this research is the creation of a database to better predict the impacts of air pollution resulting from burns leading to smoldering combustion.

  16. LBA-ECO CD-10 Forest Litter Data for km 67 Tower Site, Tapajos National Forest

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains a single text file which reports litter type and mass in the old-growth upland forest at the Para Western (Santarem) - km 67, Primary Forest...

  17. Distribution of cavity trees in midwestern old-growth and second-growth forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson; David R. Larsen

    2003-01-01

    We used classification and regression tree analysis to determine the primary variables associated with the occurrence of cavity trees and the hierarchical structure among those variables. We applied that information to develop logistic models predicting cavity tree probability as a function of diameter, species group, and decay class. Inventories of cavity abundance in...

  18. Mountain pine beetle selectivity in old-growth ponderosa pine forests, Montana, USA.

    Science.gov (United States)

    Knapp, Paul A; Soulé, Peter T; Maxwell, Justin T

    2013-05-01

    A historically unprecedented mountain pine beetle (MPB) outbreak affected western Montana during the past decade. We examined radial growth rates (AD 1860-2007/8) of co-occurring mature healthy and MPB-infected ponderosa pine trees collected at two sites (Cabin Gulch and Kitchen Gulch) in western Montana and: (1) compared basal area increment (BAI) values within populations and between sites; (2) used carbon isotope analysis to calculate intrinsic water-use efficiency (iWUE) at Cabin Gulch; and (3) compared climate-growth responses using a suite of monthly climatic variables. BAI values within populations and between sites were similar until the last 20-30 years, at which point the visually healthy populations had consistently higher BAI values (22-34%) than the MPB-infected trees. These results suggest that growth rates two-three decades prior to the current outbreak diverged between our selected populations, with the slower-growing trees being more vulnerable to beetle infestation. Both samples from Cabin Gulch experienced upward trends in iWUE, with significant regime shifts toward higher iWUE beginning in 1955-59 for the visually healthy trees and 1960-64 for the MPB-infected trees. Drought tolerance also varied between the two populations with the visually healthy trees having higher growth rates than MPB-infected trees prior to infection during a multi-decadal period of drying summertime conditions. Intrinsic water-use efficiency significantly increased for both populations during the past 150 years, but there were no significant differences between the visually healthy and MPB-infected chronologies.

  19. Piloted ignition of live forest fuels

    Science.gov (United States)

    S. McAllister; I. Grenfell; A. Hadlow; W. M. Jolly; M. Finney; J. Cohen

    2012-01-01

    The most unpredictable and uncontrollable wildfires are those that burn in the crowns of live vegetation. The fuels that feed these crown fires are mostly live, green foliage. Unfortunately, little is known about how live fuels combust. To understand how live fuels burn, piloted ignition experiments were performed with lodgepole pine and Douglas-fir. The thermal...

  20. Reference conditions for old-growth redwood restoration on alluvial flats

    Science.gov (United States)

    Christa M. Dagley; John-Pascal. Berrill

    2012-01-01

    We quantified structural attributes in three alluvial flat old-growth coast redwood stands. Tree size parameters and occurrences of distinctive features (e.g., burls, goose pens) were similar between stands. Occurrence of distinctive features was greater among larger trees. Tree sizefrequency distributions conformed to a reverse-J diameter distribution. The range of...

  1. Ecological restoration of an old-growth longleaf pine stand utilizing prescribed fire

    Science.gov (United States)

    J. Morgan Varner; John S. Kush; Ralph S. Meldahl

    2000-01-01

    Ecological restoration using prescribed fire has been underway for 3 years in an uncut, old-growth longleaf pine (Pinus palustris) stand located in south Alabama. The longleaf pine ecosystem requires frequent (once every 1-10 years) surface fire to prevent succesion to later several stages. Before this study began, this stand had not burned in >...

  2. Abundance of Armillaria within old-growth eastern hemlock stands in South-Central Pennsylvania

    Science.gov (United States)

    Matthew S. Fromm; Donald D. Davis

    2007-01-01

    Abstract—In early summer 2002, 329 soil-sampling pits were dug within an old-growth, eastern hemlock (Tsuga canadensis [L.] Carrière) stand in south-central Pennsylvania recently infested with the hemlock woolly adelgid (Adelges tsugae Annand). For comparison, 199 similar pits were dug in an adjacent hardwood stand. Rhizomorphs of...

  3. Edge effects and the effective size of old-growth coast redwood preserves

    Science.gov (United States)

    William H. Russell; Joe R. McBride; Ky Carnell

    2000-01-01

    Data were collected to determine the depth of influence of conditions created by clear-cut timber harvest on adjacent old-growth stands of coast redwood. Fourteen variables related to stand structure and composition, wildlife habitat, and physical environment exhibited significant correlation to distance from the timber harvest boundary. Results were applied to the...

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

    Directory of Open Access Journals (Sweden)

    Andrew D. Cameron

    2015-02-01

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

  5. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

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

  6. Interactions between leaf nitrogen status and longevity in relation to N cycling in three contrasting European forest canopies

    Science.gov (United States)

    Wang, L.; Ibrom, A.; Korhonen, J. F. J.; Arnoud Frumau, K. F.; Wu, J.; Pihlatie, M.; Schjoerring, J. K.

    2012-07-01

    Seasonal and spatial variations in foliar nitrogen (N) parameters were investigated in three European forests with different tree species, viz. beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga menziesii, Mirb., Franco) and Scots pine (Pinus sylvestris L.) in Denmark, The Netherlands and Finland, respectively. This was done in order to obtain information about functional acclimation, tree internal N conservation and its relevance for both ecosystem internal N cycling and foliar N exchange with the atmosphere. Leaf N pools generally showed much higher seasonal variability in beech trees than in the coniferous canopies. The concentrations of N and chlorophyll in the beech leaves were synchronized with the seasonal course of solar radiation implying close physiological acclimation, which was not observed in the coniferous needles. During phases of intensive N metabolism in the beech leaves, the NH4+ concentration rose considerably. This was compensated for by a strong pH decrease resulting in relatively low Γ values (ratio between tissue NH4+ and H+). The Γ values in the coniferous were even smaller than in beech, indicating low probability of NH3 emissions from the foliage to the atmosphere as an N conserving mechanism. The reduction in foliage N content during senescence was interpreted as N re-translocation from the senescing leaves into the rest of the trees. The N re-translocation efficiency (ηr) ranged from 37 to 70% and decreased with the time necessary for full renewal of the canopy foliage. Comparison with literature data from in total 23 tree species showed a general tendency for ηr to on average be reduced by 8% per year the canopy stays longer, i.e. with each additional year it takes for canopy renewal. The boreal pine site returned the lowest amount of N via foliage litter to the soil, while the temperate Douglas fir stand which had the largest peak canopy N content and the lowestηr returned the highest amount of N to the soil. These results

  7. Tree ring evidence for limited direct CO2 fertilization of forests over the 20th century

    Science.gov (United States)

    Gedalof, Ze'ev; Berg, Aaron A.

    2010-09-01

    The effect that rising atmospheric CO2 levels will have on forest productivity and water use efficiency remains uncertain, yet it has critical implications for future rates of carbon sequestration and forest distributions. Efforts to understand the effect that rising CO2 will have on forests are largely based on growth chamber studies of seedlings, and the relatively small number of FACE sites. Inferences from these studies are limited by their generally short durations, artificial growing conditions, unnatural step-increases in CO2 concentrations, and poor replication. Here we analyze the global record of annual radial tree growth, derived from the International Tree ring Data Bank (ITRDB), for evidence of increasing growth rates that cannot be explained by climatic change alone, and for evidence of decreasing sensitivity to drought. We find that approximately 20 percent of sites globally exhibit increasing trends in growth that cannot be attributed to climatic causes, nitrogen deposition, elevation, or latitude, which we attribute to a direct CO2 fertilization effect. No differences were found between species in their likelihood to exhibit growth increases attributable to CO2 fertilization, although Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa), the two most commonly sampled species in the ITRDB, exhibit a CO2 fertilization signal at frequencies very near their upper and lower confidence limits respectively. Overall these results suggest that CO2 fertilization of forests will not counteract emissions or slow warming in any substantial fashion, but do suggest that future forest dynamics may differ from those seen today depending on site conditions and individual species' responses to elevated CO2.

  8. Calcium oxalate contribution to calcium cycling in forests of contrasting nutrient status

    Science.gov (United States)

    Dauer, Jenny M.; Perakis, Steven S.

    2014-01-01

    Calcium oxalate (Ca oxalate) is an insoluble biomineral that forms in plants and fungi, and occurs in soils across many types of ecosystems. Assessing how Ca oxalate may shape ecosystem Ca cycling requires information on the distribution of Ca oxalate among plant biomass, detritus, and mineral soil, and how it varies with ecosystem Ca status. We compared two Douglas-fir forests of contrasting ecosystem Ca availability, and found that Ca oxalate was partitioned similarly among plant biomass, detritus and mineral soil major ecosystem compartments at both sites, and total pools of Ca oxalate were greater in the high-Ca forest. However, the proportional importance of Ca oxalate was greater in the low-Ca than high-Ca forest (18% versus 4% of actively cycling ecosystem Ca, respectively). And calcium oxalate in mineral soil, which is of particular interest as a potential long-term Ca reservoir, was a larger portion of total available Ca (exchangeable Ca plus Ca oxalate Ca) in the low-Ca site than the high-Ca site (9% versus 1% of available soil Ca, respectively). Calcium oxalate was the dominant form of Ca returned from plants to soil as leaf litterfall at the high-Ca site, yet calcium oxalate disappeared rapidly from decomposing litter (0.28 yr−1 or faster) at both sites. We conclude that accumulation of Ca oxalate in forest ecosystems appears most closely related to overall Ca supply for live biomass pools, and that the accumulation of Ca oxalate in forest floor and mineral soil is limited by rapid microbial degradation of putatively unavailable Ca oxalate.

  9. Diversity of Medicinal Plants among Different Forest-use Types of the Pakistani Himalaya.

    Science.gov (United States)

    Adnan, Muhammad; Hölscher, Dirk

    2012-12-01

    Diversity of Medicinal Plants among Different Forest-use Types of the Pakistani Himalaya Medicinal plants collected in Himalayan forests play a vital role in the livelihoods of regional rural societies and are also increasingly recognized at the international level. However, these forests are being heavily transformed by logging. Here we ask how forest transformation influences the diversity and composition of medicinal plants in northwestern Pakistan, where we studied old-growth forests, forests degraded by logging, and regrowth forests. First, an approximate map indicating these forest types was established and then 15 study plots per forest type were randomly selected. We found a total of 59 medicinal plant species consisting of herbs and ferns, most of which occurred in the old-growth forest. Species number was lowest in forest degraded by logging and intermediate in regrowth forest. The most valuable economic species, including six Himalayan endemics, occurred almost exclusively in old-growth forest. Species composition and abundance of forest degraded by logging differed markedly from that of old-growth forest, while regrowth forest was more similar to old-growth forest. The density of medicinal plants positively correlated with tree canopy cover in old-growth forest and negatively in degraded forest, which indicates that species adapted to open conditions dominate in logged forest. Thus, old-growth forests are important as refuge for vulnerable endemics. Forest degraded by logging has the lowest diversity of relatively common medicinal plants. Forest regrowth may foster the reappearance of certain medicinal species valuable to local livelihoods and as such promote acceptance of forest expansion and medicinal plants conservation in the region. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12231-012-9213-4) contains supplementary material, which is available to authorized users.

  10. Functional structure of ant and termite assemblages in old growth forest, logged forest and oil palm plantation in Malaysian Borneo

    Czech Academy of Sciences Publication Activity Database

    Luke, S. H.; Fayle, Tom Maurice; Eggleton, P.; Turner, E. C.; Davies, R. G.

    2014-01-01

    Roč. 23, č. 11 (2014), s. 2817-2832 ISSN 0960-3115 R&D Projects: GA ČR GA14-32302S Grant - others:European Social Fund(CZ) CZ.1.07/2.3.00/20.0064; Australïan Research Council Discovery Grant(AU) DP140101541 Institutional support: RVO:60077344 Keywords : feeding groups * formicidae * functional groups Subject RIV: EH - Ecology, Behaviour Impact factor: 2.365, year: 2014 http://link.springer.com/article/10.1007%2Fs10531-014-0750-2

  11. Monoterpene concentration in Douglas-fir in relation to geographic location and resistance to attack by the Douglas-fir beetle

    Science.gov (United States)

    J.W. Hanover; M.M. Furniss

    1966-01-01

    The concentration of monoterpenes in Pinus monticola Dougl. has been shown to be genetically controlled (Hanover, in preparation). Genetic control of terpene concentration has been implied, also, from analyses of parents or interspecies hybrids in other species (Bannister et al. 1959; Williams and Bannister 1962; Smith 1964, and Forde 1964). Evidence...

  12. Proceedings from the conference on the ecology and management of high-elevation forests in the central and southern Appalachian Mountains

    Science.gov (United States)

    James S. Rentch; Thomas M. Schuler

    2010-01-01

    The proceedings includes 18 peer-reviewed papers and 41 abstracts pertaining to acid deposition and nutrient cycling, ecological classification, forest dynamics, avifauna, wildlife and fisheries, forests pests, climate change, old-growth forest structure, regeneration, and restoration.

  13. LBA-ECO CD-10 Forest Litter Data for km 67 Tower Site, Tapajos National Forest

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains a single text file which reports litter type and mass in the old-growth upland forest at the Para Western (Santarem) - km 67,...

  14. Application of Lidar remote sensing to the estimation of forest canopy and stand structure

    Science.gov (United States)

    Lefsky, Michael Andrew

    A new remote sensing instrument, SLICER (Scanning Lidar Imager of Canopies by Echo Recovery), has been applied to the problem of remote sensing the canopy and stand structure of two groups of deciduous forests, Tulip Poplar-Oak stands in the vicinity of Annapolis, MD. and bottomland hardwood stands near Williamston, NC. The ability of the SLICER instrument to remotely sense the vertical distribution of canopy structure (Canopy Height Profile), bulk canopy transmittance, and several indices of canopy height has been successfully validated using twelve stands with coincident field and SLICER estimates of canopy structure. Principal components analysis has been applied to canopy height profiles from both field sites, and three significant factors were identified, each closely related to the amount of foliage in a recognizable layer of the forest, either understory, midstory, or overstory. The distribution of canopy structure to these layers is significantly correlated with the size and number of stems supporting them. The same layered structure was shown to apply to both field and SLICER remotely sensed canopy height profiles, and to apply to SLICER remotely sensed canopy profiles from both the bottomland hardwood stands in the coastal plain of North Carolina, and to mesic Tulip-Poplars stands in the upland coastal plain of Maryland. Linear regressions have demonstrated that canopy and stand structure are correlated to both a statistically significant and useful degree. Stand age and stem density is more highly correlated to stand height, while stand basal area and aboveground biomass are more closely related to a new measure of canopy structure, the quadratic mean canopy height. A geometric model of canopy structure has been shown to explain the differing relationships between canopy structure and stand basal area for stands of Eastern Deciduous Forest and Douglas Fir Forest.

  15. Nitrogen dynamics across silvicultural canopy gaps in young forests of western Oregon

    Science.gov (United States)

    Thiel, A.L.; Perakis, S.S.

    2009-01-01

    Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. The effect of gap creation on available nitrogen (N) is of concern to managers because N is often a limiting nutrient in Pacific Northwest forests. We investigated patterns of N availability in the forest floor and upper mineral soil (0-10 cm) across 6-8-year-old silvicultural canopy gaps in three 50-70-year-old Douglas-fir forests spanning a wide range of soil N capital in the Coast Range and Cascade Mountains of western Oregon. We used extractable ammonium (NH4+) and nitrate (NO3-) pools, net N mineralization and nitrification rates, and NH4+ and NO3- ion exchange resin (IER) concentrations to quantify N availability along north-south transects run through the centers of 0.4 and 0.1 ha gaps. In addition, we measured several factors known to influence N availability, including litterfall, moisture, temperature, and decomposition rates. In general, gap-forest differences in N availability were more pronounced in the mineral soil than in the forest floor. Mineral soil extractable NH4+ and NO3- pools, net N mineralization and nitrification rates, and NH4+ and NO3- IER concentrations were all significantly elevated in gaps relative to adjacent forest, and in several cases exhibited significantly greater spatial variability in gaps than forest. Nitrogen availability along the edges of gaps more often resembled levels in the adjacent forest than in gap centers. For the majority of response variables, there were no significant differences between northern and southern transect positions, nor between 0.4 and 0.1 ha gaps. Forest floor and mineral soil gravimetric percent moisture and temperature showed few differences along transects, while litterfall carbon (C) inputs and litterfall C:N ratios in gaps were significantly lower than in the adjacent forest. Reciprocal transfer incubations of

  16. Accelerating the development of old-growth characteristics in second-growth northern hardwoods

    Science.gov (United States)

    Karin S. Fassnacht; Dustin R. Bronson; Brian J. Palik; Anthony W. D' Amato; Craig Lorimer; Karl J. Martin

    2015-01-01

    Active management techniques that emulate natural forest disturbance and stand development processes have the potential to enhance species diversity, structural complexity, and spatial heterogeneity in managed forests, helping to meet goals related to biodiversity, ecosystem health, and forest resilience in the face of uncertain future conditions. There are a number of...

  17. Cutover tropical forest productivity potential merits assessment, Puerto Rico

    Science.gov (United States)

    Frank H. Wadsworth; Brynne Bryan; Julio Figueroa-Colón

    2010-01-01

    Timber extraction continues to add to vast cutover tropical forests. They are unattractive economically because of the loss of merchantable timber and the long delay foreseen for recovery. Despite this, wood in cutover tropical forests is in line to become more marketable as demand continues and old-growth forests become less accessible. In a cutover forest in Puerto...

  18. NPP Boreal Forest: Kuusamo, Finland, 1967-1972, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains three files (.txt format). One file provides stand characteristics, biomass, and production allocation data for an old-growth boreal forest...

  19. Forests

    International Nuclear Information System (INIS)

    Melin, J.

    1997-01-01

    Forests have the capacity to trap and retain radionuclides for a substantial period of time. The dynamic behaviour of nutrients, pollution and radionuclides in forests is complex. The rotation period of a forest stand in the Nordic countries is about 100 years, whilst the time for decomposition of organic material in a forest environment can be several hundred years. This means that any countermeasure applied in the forest environment must have an effect for several decades, or be reapplied continuously for long periods of time. To mitigate the detrimental effect of a contaminated forest environment on man, and to minimise the economic loss in trade of contaminated forest products, it is necessary to understand the mechanisms of transfer of radionuclides through the forest environment. It must also be stressed that any countermeasure applied in the forest environment must be evaluated with respect to long, as well as short term, negative effects, before any decision about remedial action is taken. Of the radionuclides studied in forests in the past, radiocaesium has been the main contributor to dose to man. In this document, only radiocaesium will be discussed since data on the impact of other radionuclides on man are too scarce for a proper evaluation. (EG)

  20. Mapping change of older forest with nearest-neighbor imputation and Landsat time-series

    Science.gov (United States)

    Janet L. Ohmann; Matthew J. Gregory; Heather M. Roberts; Warren B. Cohen; Robert E. Kennedy; Zhiqiang. Yang

    2012-01-01

    The Northwest Forest Plan (NWFP), which aims to conserve late-successional and old-growth forests (older forests) and associated species, established new policies on federal lands in the Pacific Northwest USA. As part of monitoring for the NWFP, we tested nearest-neighbor imputation for mapping change in older forest, defined by threshold values for forest attributes...

  1. Redefining Secondary Forests in the Mexican Forest Code: Implications for Management, Restoration, and Conservation

    Directory of Open Access Journals (Sweden)

    Francisco J. Román-Dañobeytia

    2014-05-01

    Full Text Available The Mexican Forest Code establishes structural reference values to differentiate between secondary and old-growth forests and requires a management plan when secondary forests become old-growth and potentially harvestable forests. The implications of this regulation for forest management, restoration, and conservation were assessed in the context of the Calakmul Biosphere Reserve, which is located in the Yucatan Peninsula. The basal area and stem density thresholds currently used by the legislation to differentiate old-growth from secondary forests are 4 m2/ha and 15 trees/ha (trees with a diameter at breast height of >25 cm; however, our research indicates that these values should be increased to 20 m2/ha and 100 trees/ha, respectively. Given that a management plan is required when secondary forests become old-growth forests, many landowners avoid forest-stand development by engaging slash-and-burn agriculture or cattle grazing. We present evidence that deforestation and land degradation may prevent the natural regeneration of late-successional tree species of high ecological and economic importance. Moreover, we discuss the results of this study in the light of an ongoing debate in the Yucatan Peninsula between policy makers, non-governmental organizations (NGOs, landowners and researchers, regarding the modification of this regulation to redefine the concept of acahual (secondary forest and to facilitate forest management and restoration with valuable timber tree species.

  2. Impact of fire in two old-growth montane longleaf pine stands

    Science.gov (United States)

    John S. Kush; John C. Gilbert; Crystal Lupo; Na Zhou; Becky Barlow

    2013-01-01

    The structure of longleaf pine (Pinus palustris Mill.) forests of the Southeastern United States Coastal Plains has been the focus of numerous studies. By comparison, the forests in the mountains of Alabama and Georgia are not well understood. Less than 1 percent of longleaf pine stands found in the montane portion of longleaf’s range are considered...

  3. 'Pygmy' old-growth redwood characteristics on an edaphic ecotone in Mendocino County, California

    Science.gov (United States)

    Will Russell; Suzie. Woolhouse

    2012-01-01

    The 'pygmy forest' is a specialized community that is adapted to highly acidic, hydrophobic, nutrient deprived soils, and exists in pockets within the coast redwood forest in Mendocino County. While coast redwood is known as an exceptionally tall tree, stunted trees exhibit unusual growth-forms on pygmy soils. We used a stratified random sampling procedure to...

  4. Selected yield tables for plantations and natural stands in Inland Northwest Forests

    Science.gov (United States)

    Albert R. Stage; David L. Renner; Roger C. Chapman

    1988-01-01

    Yields arrayed by site index and age have been tabulated for plantations of 500 trees per acre, with five thinning regimes, for Douglas-fir, grand fir, and western larch. Yields were also tabulated for naturally regenerated stands of the grand fir-cedar-hemlock ecosystem of the Inland Empire. All yields were estimated with the Prognosis Model for Stand Development,...

  5. Dwarf mistletoe and host tree interactions in managed forests of the Pacific Northwest.

    Science.gov (United States)

    Donald M. Knutson; Robert. Tinnin

    1980-01-01

    Dwarf mistletoes in the Pacific Northwest infect true firs, larch, pine, Douglas-fir, and hemlock. Forty-one percent of all stands east of the crest of the Cascade Range and 10 percent of west-side stands are infected. General characteristics of dwarf mistletoe are discussed including mortality and growth losses rate of spread within a tree and within stands. Relation...

  6. How can we increase the production, quality and health of our forests by selective breeding

    Energy Technology Data Exchange (ETDEWEB)

    Nanson, A

    1981-01-01

    Selective breeding programmes in Belgium are discussed, and a number of seed plantations are listed. Descriptions are given of the performance of European provenances of spruce and larch and American and Canadian Douglas fir, at 3 plantations in Belgium. An account is given of Belgian success in breeding varieties of spruce with late-opening buds resistant to late frosts. (Refs. 8).

  7. 77 FR 19177 - Beaverhead-Deerlodge National Forest, Jefferson Ranger District, Montana, Boulder River Salvage...

    Science.gov (United States)

    2012-03-30

    ... statement. SUMMARY: The project proposes to salvage by clearcut harvest dead and lodgepole pine infested or... Need for Action The purpose and need for this project is to harvest merchantable wood products from..., before the value of the wood deteriorates; reduce stand density in lodgepole pine and Douglas-fir stands...

  8. Biophysical constraints on leaf expansion in a tall conifer.

    Science.gov (United States)

    Fredrick C. Meinzer; Barbara J. Bond; Jennifer A. Karanian

    2008-01-01

    The physiological mechanisms responsible for reduced extension growth as trees increase in height remain elusive. We evaluated biophysical constraints on leaf expansion in old-growth Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) trees. Needle elongation rates, plastic and elastic extensibility, bulk leaf water, (L...

  9. Estimating tree bole and log weights from green densities measured with the Bergstrom Xylodensimeter.

    Science.gov (United States)

    Dale R. Waddell; Michael B. Lambert; W.Y. Pong

    1984-01-01

    The performance of the Bergstrom xylodensimeter, designed to measure the green density of wood, was investigated and compared with a technique that derived green densities from wood disk samples. In addition, log and bole weights of old-growth Douglas-fir and western hemlock were calculated by various formulas and compared with lifted weights measured with a load cell...

  10. Douglas-fir nutrients and terpenes as potential factors influencing western spruce budworm defoliation

    Science.gov (United States)

    Karen M. Clancy

    1991-01-01

    Variation in levels of herbivory within and among plants can be attributed to many mechanisms, such as differences in a) host nutritional quality, b) suitability of the physical environment, and c) abundance of competitor consumers or natural enemies (Mattson et al. 1982, Denno and McClure 1983, Mattson and Scriber 1987, Clancy et al. 1988a, 1988b, Mattson et al. 1988...

  11. Simulation of growth and competition in mixed stands of Douglas-fir and beech

    NARCIS (Netherlands)

    Bartelink, H.H.

    1998-01-01

    For a long time, the emphasis in silviculture in Western Europe was solely on even-aged, monospecific stands; many empirical stand-level growth models were developed and successfully used for managing such stands. In contrast, no generally accepted growth and yield approach has emerged so

  12. Genotype * environment interaction: a case study for Douglas-fir in western Oregon.

    Science.gov (United States)

    Robert K. Campbell

    1992-01-01

    Unrecognized genotype x environment interactions (g,e) can bias genetic-gain predictions and models for predicting growth dynamics or species perturbations by global climate change. This study tested six sets of families in 10 plantation sites in a 78-thousand-hectare breeding zone. Plantation differences accounted for 71 percent of sums of squares (15-year heights),...

  13. Phylogeographic analysis of the Douglas-fir beetle Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae: Scolytinae)

    Science.gov (United States)

    Enrico A. Ruíz; Jane L. Hayes; John E. Rinehart; G. Zúñiga

    2007-01-01

    Population genetic structure studies made in genus Dendroctonus have been conducted from the perspectives of allopatric and sympatric models. In the first case, host effect and historical contingency were not recognized as a source of variation, while the later considered the host itself as a source of reproductive isolation. Nevertheless, both...

  14. FIRE RESISTANCE OF DOUGLAS FIR [Pseudotsuga menziesii (Mirb. Franco] WOOD TREATED WITH SOME CHEMICALS

    Directory of Open Access Journals (Sweden)

    M. Kemal YALINKILIÇ

    1998-02-01

    Full Text Available Combustible properties of treated douglas wood specimens and fire-retardancy of some preservatives were tested in this study. Crib test of ASTM E 160-150 was followed. Results indicated that, aqueous solutions of boric acid (BA, borax (Bx (Na2BO7 10H2O or BA + Bx mixture (7: 3, w: w had fire retardant efficacy (FRE over untreated wood and reduced the combustibility of vinil monomers (Styrene and methylmetacrylate which were applied as secondary treatment.

  15. Pythium and Fusarium Species Associated with Production of Douglas-Fir Seedlings

    Science.gov (United States)

    Methyl bromide has long been used to control Pythium and Fusarium spp. in conifer nurseries in the Pacific Northwest. However, alternative fumigants are now necessary as methyl bromide is an ozone-depleting agent. The efficacy of metam sodium, dimethyl disulfide, and methyl iodide against Pythium ...

  16. Major outbreaks of the Douglas-fir tussock moth in Oregon and California.

    Science.gov (United States)

    Boyd E. Wickman; Richard R. Mason; C.G. Thompson

    1973-01-01

    Case histories of five tussock moth outbreaks that occurred in California and Oregon between 1935 and 1965 are discussed. Information is given on the size and duration of the outbreaks, the presence of natural control agents and the damage caused. Most of the outbreaks were eventually treated with DDT. However, enough information was available from untreated portions...

  17. Age trends in Douglas-fir genetic parameters and implications for optimum selection age.

    Science.gov (United States)

    G.R. Johnson; R.A. Sniezko; N.L. Mandel

    1997-01-01

    rends in genetic variation were examined over 51 progeny test sites throughout western Oregon. Narrow sense heritabilities for height and diameter showed an increasing trend to age 25, the oldest age examined. Before age 10, height heritabilities were relatively unstable. Type B site-site genetic correlations increased slowly with age for height and remained relatively...

  18. Breeding graft-compatible Douglas-fir rootstocks (Pseudotsuga menziesii (Mirb.) Franco).

    Science.gov (United States)

    D.L. Copes

    1999-01-01

    A study encompassing 24 years was conducted to determine if a breeding program could produce highly graft-compatible rootstocks. Twenty-seven trees of apparent high graft compatibility were selected and crossed to produce 226 control-pollinated families. Seedlings were grown, field planted, and grafted with test scions. Graft unions from field tests were evaluated...

  19. Heat sterilization time of ponderosa pine and Douglas-fir boards and square timbers

    Science.gov (United States)

    William T. Simpson; Xiping Wang; Steve Verrill

    2003-01-01

    To prevent the unintentional transfer of insects and pathogens during world trade, wood products are often heat sterilized. The general requirement is that the center of the wood configuration be held at 133°F (56°C) for 30 min. However, many factors can affect the time required to reach this temperature. This study explored several of these factors, including...

  20. The impacts of water stress on phloem transport in Douglas-fir trees

    Science.gov (United States)

    David Woodruff

    2014-01-01

    Despite the critical role that phloem plays in a number of plant functional processes and the potential impact of water stress on phloem structural and phloem sap compositional characteristics, little research has been done to examine how water stress influences phloem transport. The objectives of this study were to develop a more accurate understanding of how water...

  1. Tolerance to multiple climate stressors: a case study of Douglas-fir drought and cold hardiness

    Science.gov (United States)

    Sheel Bansal; Connie Harrington; Brad St. Clair

    2016-01-01

    1. Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations. 2. We assessed the...

  2. Tree damage from skyline logging in a western larch/Douglas-fir stand

    Science.gov (United States)

    Robert E. Benson; Michael J. Gonsior

    1981-01-01

    Damage to shelterwood leave trees and to understory trees in shelterwood and clearcut logging units logged with skyline yarders was measured, and related to stand conditions, harvesting specifications, and yarding system-terrain interactions. About 23 percent of the marked leave trees in the shelterwood units were killed in logging, and about 10 percent had moderate to...

  3. Original Paper Floristic and structural changes in secondary forests ...

    African Journals Online (AJOL)

    Data from the first inventory in secondary and old-growth forests were ... Structural changes in secondary forests are less known in West Africa, and ... temporal succession from one time spatial ..... s = number of species sampled per hectare; S = species richness of the whole forest; NF = the number of taxonomic families,.

  4. Investigating Forest Inventory and Analysis-collected tree-ring data from Utah as a proxy for historical climate

    Science.gov (United States)

    R. Justin DeRose; W. Shih-Yu (Simon) Wang; John D. Shaw

    2012-01-01

    Increment cores collected as part of the periodic inventory in the Intermountain West were examined for their potential to represent growth and be a proxy for climate (precipitation) over a large region (Utah). Standardized and crossdated time-series created from pinyon pine (n=249) and Douglas-fir (n=274) increment cores displayed spatiotemporal patterns in growth...

  5. Linking spatiotemporal disturbance history with tree regeneration and diversity in an old-growth forest in northern Japan

    Czech Academy of Sciences Publication Activity Database

    Altman, Jan; Fibich, Pavel; Lepš, J.; Uemura, S.; Hara, T.; Doležal, Jiří

    2016-01-01

    Roč. 21, č. 1 (2016), s. 1-13 ISSN 1433-8319 R&D Projects: GA ČR(CZ) GA14-12262S; GA ČR GAP504/12/1952; GA ČR GA13-13368S Institutional support: RVO:67985939 Keywords : Tree rings * Disturbance * Spatial pattern Subject RIV: EH - Ecology, Behaviour Impact factor: 3.123, year: 2016

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

  7. Relationships between growth, quality, and stocking within managed old-growth northern hardwoods

    Science.gov (United States)

    Chris Gronewold; Anthony W. D' Amato; Brian J. Palik

    2012-01-01

    An understanding of long-term growth dynamics is central to the development of sustainable uneven-aged silvicultural systems for northern hardwood forests in eastern North America. Of particular importance are quantitative assessments of the relationships between stocking control and long-term growth and quality development. This study examined these relationships in a...

  8. Forest fragmentation in Vietnam : Effects on tree diversity, populations and genetics

    NARCIS (Netherlands)

    Ha, V.T.

    2015-01-01

    Millions of square kilometers of the Earth’s surface is covered by forest fragments, and a quarter of remaining tropical forest has been fragmented. In Southeast Asia, about 650,000 ha of natural forests are fragmented per year. Fragmentation of old growth forests is considered to be the greatest

  9. The role of old forests and big trees in forest carbon sequestration in the Pacific Northwest

    Science.gov (United States)

    Andrew N. Gray

    2015-01-01

    Forest ecosystems are an important component of the global carbon (C) cycle. Recent research has indicated that large trees in general, and old-growth forests in particular, sequester substantial amounts of C annually. C sequestration rates are thought to peak and decline with stand age but the timing and controls are not well-understood. The objectives of this study...

  10. NPP Tropical Forest: Consistent Worldwide Site Estimates, 1967-1999, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains documented field measurements of NPP components for 39 old-growth tropical forests distributed worldwide between latitudes 23.58 N and 23.58...

  11. Ectomycorrhizal Community Structure and Soil Characteristics of Mature Lodgepole Pine (Pinus Contorta) and Adjacent Stands of Old Growth Mixed Conifer in Yellowstone National Park, Wyoming USA

    Science.gov (United States)

    Douglas, Robert B.; Parker, V. Thomas; Cullings, Kenneth W.; Sun, Sidney (Technical Monitor)

    2003-01-01

    Forest development patterns following disturbance are known to influence the physical and chemical attributes of soils at different points in time. Changes in soil resources are thought to have a corresponding effect on ectomycorrhizal (ECM) community structure. We used molecular methods to compare below-ground ECM species richness, composition, and abundance between adjacent stands of homogenous lodgepole pine and old growth mixed conifer in Yellowstone National Park (YNP). In each stand-type we collected soil cores to both identify mycorrhizae and assess soil chemistry. Although no statistical difference was observed in the mean number of ECM root tips per core between stand types, the total number of species identified (85 versus 35) and the mean number of species per core (8.8 +/- 0.6 versus 2.5 +/- 0.3) were significantly higher in lodgepole pine. Differences between the actual and estimated species richness levels indicated that these forest types support a high number of ECM species and that undersampling was severe. Species compositions were widely disparate between stands where only four species were shared out of a total of 116. Soil analysis also revealed that mixed conifer was significantly lower in pH, but higher in organic matter, potassium, phosphorus, and ammonium when compared to lodgepole pine stands. Species richness per core was correlated with these chemical data, however, analysis of covariance indicated that stand type was the only statistically significant factor in the observed difference in species richness. Our data suggest that ECM fungal richness increases as homogenous lodgepole pine stands grow and mature, but declines after Engelmann spruce and subalpine fir colonize. Despite difficulties linking species composition with soil chemistry, there are a variety of physical and chemical factors that could be influencing ECM community structure. Future field experiments are necessary to test some of the mechanisms potentially operating

  12. Evaluation and improvement of the Community Land Model (CLM4 in Oregon forests

    Directory of Open Access Journals (Sweden)

    T. W. Hudiburg

    2013-01-01

    -arid pine site and spring GPP was overestimated at the Campbell River mesic Douglas-fir site, indicating GPP may be an area for further improvement. The low bias in summer maximum GPP at the semi-arid site could be due to seasonal response of Vcmax to temperature and precipitation while overestimated spring values at the mesic site could be due to response of Vcmax to temperature and day length.

  13. Low Tree-Growth Elasticity of Forest Biomass Indicated by an Individual-Based Model

    Directory of Open Access Journals (Sweden)

    Robbie A. Hember

    2018-01-01

    Full Text Available Environmental conditions and silviculture fundamentally alter the metabolism of individual trees and, therefore, need to be studied at that scale. However, changes in forest biomass density (Mg C ha−1 may be decoupled from changes in growth (kg C year−1 when the latter also accelerates the life cycle of trees and strains access to light, nutrients, and water. In this study, we refer to an individual-based model of forest biomass dynamics to constrain the magnitude of system feedbacks associated with ontogeny and competition and estimate the scaling relationship between changes in tree growth and forest biomass density. The model was driven by fitted equations of annual aboveground biomass growth (Gag, probability of recruitment (Pr, and probability of mortality (Pm parameterized against field observations of black spruce (Picea mariana (Mill. BSP, interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn. Franco, and western hemlock (Tsuga heterophylla (Raf. Sarg.. A hypothetical positive step-change in mean tree growth was imposed half way through the simulations and landscape-scale responses were then evaluated by comparing pre- and post-stimulus periods. Imposing a 100% increase in tree growth above calibrated predictions (i.e., contemporary rates only translated into 36% to 41% increases in forest biomass density. This corresponded with a tree-growth elasticity of forest biomass (εG,SB ranging from 0.33 to 0.55. The inelastic nature of stand biomass density was attributed to the dependence of mortality on intensity of competition and tree size, which decreased stand density by 353 to 495 trees ha−1, and decreased biomass residence time by 10 to 23 years. Values of εG,SB depended on the magnitude of the stimulus. For example, a retrospective scenario in which tree growth increased from 50% below contemporary rates up to contemporary rates indicated values of εG,SB ranging from 0.66 to 0.75. We conclude that: (1 effects of

  14. Mixed-conifer forests of central Oregon: effects of logging and fire exclusion vary with environment.

    Science.gov (United States)

    Merschel, Andrew G; Spies, Thomas A; Heyerdahl, Emily K

    Twentieth-century land management has altered the structure and composition of mixed-conifer forests and decreased their resilience to fire, drought, and insects in many parts of the Interior West. These forests occur across a wide range of environmental settings and historical disturbance regimes, so their response to land management is likely to vary across landscapes and among ecoregions. However, this variation has not been well characterized and hampers the development of appropriate management and restoration plans. We identified mixed-conifer types in central Oregon based on historical structure and composition, and successional trajectories following recent changes in land use, and evaluated how these types were distributed across environmental gradients. We used field data from 171 sites sampled across a range of environmental settings in two subregions: the eastern Cascades and the Ochoco Mountains. We identified four forest types in the eastern Cascades and four analogous types with lower densities in the Ochoco Mountains. All types historically contained ponderosa pine, but differed in the historical and modern proportions of shade-tolerant vs. shade-intolerant tree species. The Persistent Ponderosa Pine and Recent Douglas-fir types occupied relatively hot–dry environments compared to Recent Grand Fir and Persistent Shade Tolerant sites, which occupied warm–moist and cold–wet environments, respectively. Twentieth-century selective harvesting halved the density of large trees, with some variation among forest types. In contrast, the density of small trees doubled or tripled early in the 20th century, probably due to land-use change and a relatively cool, wet climate. Contrary to the common perception that dry ponderosa pine forests are the most highly departed from historical conditions, we found a greater departure in the modern composition of small trees in warm–moist environments than in either hot–dry or cold–wet environments. Furthermore

  15. Comparison of Red-Cockaded Woodpecker (Piciodes borealis) Nestling Diet in Old-Growth and Old-Field Longleaf Pine (Pinus palustris)

    Energy Technology Data Exchange (ETDEWEB)

    Hanula, J.L.; Engstrom, R.T.

    1999-10-01

    Automatic cameras were used to record adult woodpecker diets in old-growth and old-field longleaf pine in the South. Roaches were the number one prey for the woodpeckers based on either biomass or numbers. The latter ranged from 37% to 57% of the prey numbers and 55%-73% of the biomass. Morisita's index of similarity between old-field and old growth varied from 0.89 to 0.95. The authors conclude that the prey base is similar in both conditions and that old-growth provides similar foraging habitat.

  16. Impact of surrounding environment evolution on long-term gas flux measurements in a temperate mixed forest

    Science.gov (United States)

    Hurdebise, Quentin; Rixen, Toma; De Ligne, Anne; Vincke, Caroline; Heinesch, Bernard; Aubinet, Marc

    2016-04-01

    With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: -displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; -turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; -tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; -measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into

  17. Long-term effects of prescribed fire on mixed conifer forest structure in the Sierra Nevada, California

    Science.gov (United States)

    Phillip J. Van Mantgem; Nathan L. Stephenson; Eric Knapp; John Barrles; Jon E. Keeley

    2011-01-01

    The capacity of prescribed fire to restore forest conditions is often judged by changes in forest structure within a few years following burning. However, prescribed fire might have longer-term effects on forest structure, potentially changing treatment assessments. We examined annual changes in forest structure in five 1 ha old-growth plots immediately before...

  18. Current net ecosystem exchange of CO2 in a young mixed forest: any heritage from the previous ecosystem?

    Science.gov (United States)

    Violette, Aurélie; Heinesch, Bernard; Erpicum, Michel; Carnol, Monique; Aubinet, Marc; François, Louis

    2013-04-01

    For 15 years, networks of flux towers have been developed to determine accurate carbon balance with the eddy-covariance method and determine if forests are sink or source of carbon. However, for prediction of the evolution of carbon cycle and climate, major uncertainties remain on the ecosystem respiration (Reco, which includes the respiration of above ground part of trees, roots respiration and mineralization of the soil organic matter), the gross primary productivity (GPP) and their difference, the net ecosystem exchange (NEE) of forests. These uncertainties are consequences of spatial and inter-annual variability, driven by previous and current climatic conditions, as well as by the particular history of the site (management, diseases, etc.). In this study we focus on the carbon cycle in two mixed forests in the Belgian Ardennes. The first site, Vielsalm, is a mature stand mostly composed of beeches (Fagus sylvatica) and douglas fir (Pseudotsuga menziesii) from 80 to 100 years old. The second site, La Robinette, was covered before 1995 with spruces. After an important windfall and a clear cutting, the site was replanted, between 1995 and 2000, with spruces (Piceas abies) and deciduous species (mostly Betula pendula, Aulnus glutinosa and Salix aurita). The challenge here is to highlight how initial conditions can influence the current behavior of the carbon cycle in a growing stand compared to a mature one, where initial conditions are supposed to be forgotten. A modeling approach suits particularly well for sensitivity tests and estimation of the temporal lag between an event and the ecosystem response. We use the forest ecosystem model ASPECTS (Rasse et al., Ecological Modelling 141, 35-52, 2001). This model predicts long-term forest growth by calculating, over time, hourly NEE. It was developed and already validated on the Vielsalm forest. Modelling results are confronted to eddy-covariance data on both sites from 2006 to 2011. The main difference between both

  19. Surveying marbled murrelets at inland forested sites: a guide

    Science.gov (United States)

    Peter W.C. Paton; C. John Ralph; Harry R. Carter; S. Kim Nelson

    1990-01-01

    The marbled murrelet (Brachyramphus marmoratus), a seabird, nests in forested stands from southeast Alaska south to Santa Cruz, California. Because of this species' close association with old-growth forests, researchers and land managers need a method to assess murrelet distribution and use patterns throughout its range. This guide describes a...

  20. Repeated insect outbreaks promote multi-cohort aspen mixedwood forests in Northern Minnesota, USA

    Science.gov (United States)

    Michael Reinikainen; Anthony W. D' Amato; Shawn. Fraver

    2012-01-01

    Characterizing the timing, severity, and agents of historic forest disturbances is critical to developing management and conservation strategies based on natural processes. Typically such information is derived from retrospective studies of remnant old-growth forests; however, this approach has limited application in regions dominated by secondary forests heavily...