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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Root growth potential and bud dormancy of three northern pines with emphasis on eastern white pine

Johnsen, Kurt H. January 1985 (has links)
A two year study examined Root Growth Potential (RGP) in a hydroponic system and Dormancy Release Index (DRI) in one-year-old (1-0) and two-year-old (2-0) eastern white pine (Pinus strobus L.), red pine (Pinus resinosa Ait.), and Scotch pine (Pinus sylvestris L.) seedlings with emphasis on eastern white pine. During 1985-86 all three species of 2-0 stock displayed a similar pattern of RGP with high levels of RGP limited to mid-March. Only 2-0 eastern white pine had a statistically significant relationship between RGP and DRI; however, this relationship was not consistent in 1986-87. The RGP/DRI relationship in 2-0 eastern white pine was strong over both years within a DRI range of 0.22 to 1.00. One-year-old and 2-0 eastern white pine stock had very different patterns of RGP over both years with 1-0 stock maintaining much wider "lifting windows" for high RGP. Cold storage (2C) of 2-0 eastern white pine resulted in variable effects on RGP although it typically progressed dormancy release. There were no strong RGP trends between northern and southern provenances of 1-0 eastern white pine and heritability values indicate that RGP is under minimal genetic control in 1-0 eastern white pine seedlings. Northern and southern provenances did display clear differences in seedling morphology and seasonal patterns of shoot activity. Results of a field outplanting study show that RGP does show promise as a measure of 2-0 eastern white pine seedling quality. The predictive ability of RGP was increased on non-irrigated versus irrigated seedlings. A comparison of greenhouse versus growthroorn RGP testing demonstrated the validity of using greenhouse RGP testing of 2-0 eastern white pine. / M.S.
42

The Ellison district: alteration-mineralization associated with a mid-tertiary intrusive complex at Sawmill Canyon, White Pine County, Nevada

Johnson, Lawrence Clinton January 1983 (has links)
No description available.
43

Compression wood formation in Pinus strobus L. following ice storm damage in southwestern Virginia

Hook, Benjamin Austin 21 May 2010 (has links)
To evaluate the compression wood response in eastern white pine (Pinus strobus L.) following a severe ice storm in 1994, 47 trees were felled in 2007 and cross-sectional samples were collected at 0.5 (±0.2) m stem height. The disks were sanded and digitally scanned, and the cross-sectional area (mm2) of compression wood within each tree-ring was quantified using image analysis software. Topographic data (slope, aspect, and elevation) were also recorded for each P. strobus tree, along with a modified competition index. Wood anatomical features were also quantified in the three years before and after the storm along a tree diameter gradient. Although tree age was relatively constant in this stand, tree size was influenced by topographic position; larger trees grew in the valley while smaller trees were found growing in thin soils at the mid-slope position. When the cohort was about 25 years old, ice deposition caused a heterogeneous compression wood response which was highly related to tree size. In the thirteen years following the ice storm, the 6 – 9 cm (2007) diameter class formed significantly more compression wood area than any other, followed by the 10 – 13 cm (2007) diameter class. The tree diameter range that formed the most post-storm compression wood was 4 – 8 cm at the time of the storm, suggesting that this diameter range was most affected by 8.5 cm of ice loading in P. strobus. Trees > 18 cm in 1994 did not form any compression wood after the storm, but many experienced a growth release to fill canopy gaps. Topographic variables did not influence compression wood formation directly, but only one plot was sampled so these results are tenuous. However, topography did influence tree size which was the most important predictor in compression wood. There was no relationship between compression wood area and competition index. Due to compression wood formation after the ice storm, cell wall thickness and cell circularity were significantly higher in the 1994 tree-ring than in other rings examined (1991 – 1993, 1995, and 1996). Tracheid and lumen diameters were significantly smaller in compression wood cells (30.5 and 19.5 μm, respectively) than in normal wood (36.8 and 28.4 μm, respectively); opposite wood cells were intermediate in size (32.4 and 24.4 μm, respectively). Due to small tracheid size, compression wood contained significantly more cells mm⁻¹ (33) than normal wood (27), but no significant differences in cell wall area. Therefore, cumulative cell wall area occupied 47% of the cross-section in compression wood tissue on average, compared to 31% in normal wood. Dispersing tree weight across a greater surface area may help compression wood to prop up a bent tree, but reduced lumen area may also impact hydraulic conductivity in the stem. / Master of Science
44

Habitat use by a forest-dwelling bat community in the northern Great Lakes region

Jung, Thomas S. January 2000 (has links)
To examine bat - habitat relationships, ultrasonic detectors were used to sample bat activity among: old-growth white pine (Pinus strobus ), mature white pine, boreal mixedwood, and selectively-cut white pine stands in central Ontario. Within the stands, bats were sampled in the canopy, the understory layer, and within canopy gaps. Forest structure was measured within each of the stands. The activity of bats was compared among forest stand types, within the stands, and in relation to forest structure. Also, maintaining forest wildlife populations requires data on the use of snags (i.e. dead trees). To provide further resolution of the habitat requirements of forest-dwelling bats, radio telemetry and exit counts were used to investigate the roosting ecology of mouse-eared bats (Myotis lucifugus and M. septentrionalis). Characteristics of snags used by mouse-eared bats were compared with randomly located snags and random geographic points, at three spatial scales (focal tree, surrounding forest, and landscape). (Abstract shortened by UMI.)
45

Legacies of forest management and fire in mixed-pine forest ecosystems of the Seney National Wildlife Refuge, eastern Upper Michigan

Rist, Stephen George. January 2008 (has links)
Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 74-79).
46

Western White Pine: The Effect of Clone and Cone Color on Attacks by the Mountain Pine Cone Beetle

Jenkins, Michael J 01 May 1982 (has links)
The relationship between clone and cone color in western white pine, Pinus monticola Douglas, to attack by the mountain pine cone beetle, Conophthorus monticolae Hopkins, was studied in the Sandpoint Seed Orchard, Idaho. A positive relationship was shown to exist during a 5 year field evaluation. Cone beetles were found to prefer dark colored cones and to attack certain clones at a higher rate than others. Laboratory dissections did not indicate that cone color affected oviposition, brood development or brood mortality. Olfactometer experiments demonstrated that olfactory stimuli are involved in the cone beetle attack sequence. Visual cues relating to cone color may be involved in the initial long range host orientation of attacking beetles.
47

Habitat use by a forest-dwelling bat community in the northern Great Lakes region

Jung, Thomas S. January 2000 (has links)
No description available.
48

Carbon, water, and energy dynamics of a temperate pine forest during the first decade since plantation on a former cropland

Chan, Felix January 2016 (has links)
This study presents the energy, carbon (C), and water exchange dynamics of a recently afforested temperate white pine (Pinus strobus L.) forest, established on former agricultural land in 2002, in southern Ontario, Canada during the initial thirteen years (2003–2015). Our observations show that the forest became a consistent sink of C after only 5 years of its establishment (ranging from 105 g C m–2 to 216 g C m–2 between 2008 to 2015), owing to sandy soils and low residual soil organic matter from prior agricultural activities. This region frequently experiences low precipitation (P) and soil moisture (VWC) limitations and/or heat stress in late summer, causing a reduction in net ecosystem productivity (NEP). Seasonal and annual dynamics of NEP showed reduced C uptake during years with heat and/or drought events (i.e. 2007 and 2012). In 2007, the impact of a seasonal drought was much more exacerbated when combined with a heatwave, resulting in a strong C source. Similarly, the inter-annual variability of evapotranspiration (ET) gradually increased with stand age (mean 370 mm yr–1) and water use efficiency (WUE) consistently increased (mean 2.65 g C kg–1 H2O). Quantum yield, α (0.019 to 0.045) and maximum photosynthetic capacity, Amax (4.37 to 33.6 µmol m–2s–1) increased steadily as the size and density of the canopy increased with stand age. Energy fluxes were influenced by canopy development as net radiation (Rn), latent heat (LE), and sensible heat (H) flux increased, while ground heat flux (G) peaked in 2007 and then gradually declined. Our analysis showed that daily C fluxes are primarily driven by Rn and temperature (Ts, Ta) which explained 47%, 61%, 52%, and 68% of the variability in gross ecosystem productivity (GEP), ecosystem respiration (RE), NEP, and ET. This study is a significant contribution to our understanding of the energy, C, and water dynamics of young planted conifer forests and controls on their growth and C uptake. Our findings demonstrate the potential of utilizing white pine as a means to sequester atmospheric CO2 in southern Ontario and other regions of North America with similar climate and site history. / Thesis / Master of Science (MSc)
49

Effects of Silvicultural Treatments and Soil Properties on the Establishment and Productivity of Trees Growing on Mine Soils in the Appalachian Coalfields

Casselman, Chad N. 25 May 2005 (has links)
Coal has been and will continue to be an important energy source in the U.S. for the foreseeable future. Surface mining for coal is one of the methods employed to extract this resource from below the ground. The process of surface mining removes native topsoils and any native vegetation that was support by these native soils. In the Appalachian coal-producing region of the United States, the pre-mining landscape is predominantly forested. Prior to the Surface Mining and Reclamation Act of 1977 (SMCRA), surface mined lands were commonly reclaimed to forests. Subsequent to the passage of SMCRA, reforestation of surface mined lands has decreased. As a result, thousands of hectares of land that were forested prior to mining are being reclaimed using grasses and legumes. This is done in spite of the fact that the SMCRA requires that land be reclaimed to an "equal or higher land use." The decline of reforestation stems from two main issues, namely: (1) reclaiming land to pasture is an easy and low-risk way for mining companies to obtain bond release; and (2) SMCRA reclamation requirements have led to unfavorable conditions for tree establishment and growth. Recent interest has been shown in reverting these surface mined lands that have been reclaimed to pasture back to forests for reasons related to the environmental, economic, and carbon sequestration benefits that forests are believed to have when compared to pasture land. It is believed that forests can be established on existing reclaimed pasture land through the use of silvicultural treatments, that mature stands of trees growing on surface mines will respond to treatment similarly to stands growing on native soils, and that mature stands growing on relcaimed surface mines have different soil properties controlling their growth than those that have been found for younger stands. The purpose of this investigation was to understand the biological feasibility of restoring forests on post-SMCRA surface mined lands in the Appalachian coalfields reclaimed to pasture and to understand the productive potential and factors governing the productive potential of pre-SMCRA surface mines supporting mature forests in an attempt to show the benefits of reclaiming these lands with forests. A 3x3x3 factor random complete block design was used to assess first-year survival and growth of three species assemblages under three levels of silvicultural treatment intensity at each of three study sites having different site characteristics. The native hardwood species assemblage was found to have the best survival across all three sites, with 80 and 85% survival for sites with spoils derived from shale and oxidized sandstone, respectively. White pine generally had the lowest survival of all species and ranged from 27% across treatments on siltstone spoils to 58% across treatments on oxidized sandstone spoils. Hardwood and white pine grew little over the first year, ranging from -3.7 to 8.9cm in height compared to hybrid poplar, whose height growth ranged from 22.4cm to 126.6cm. Response to silvicultural treatment was variable by site and species, but weed control in combination with tillage generally resulted in the highest survival. Greatest height growth (126.6cm) occurred on the oxidized sandstone spoil, where hybrid poplar was treated with weed control plus tillage in combination with fertilization. Hybrid poplar was found to have the greatest growth after one year compared with the hardwood and white pine and also had the greatest height growth at each level of silvicultural intensity for all sites. This superior growth should give hybrid poplar an advantage over the others used to revert these grass lands back to forests, as the amount of height growth observed (>50cm over one year in the weed control plus tillage treatment at all sites) may be enough to ensure that these trees will not succumb to aggressive competing vegetation without further weed control. The results of this study show that based on first-year data, reforestation of these lands does appear to be biologically feasible, given the species and treaments used. In an attempt to quantify the productivity of a 26-year-old white pine stand established pre-SMCRA, a random complete block experiment was used to compare the response to a thinning that occurred in this stand at age 17. Site index of the stand was found to be 32.3m at base age 50, indicating that this is a very productive stand. Neither stand volume nor stand value was statistically different at age 26 between treatments with volumes and values ranging from 290m3ha-1 and $5639 ha-1 to 313 m3ha-1 and $5478 ha-1 for the thinned and unthinned treatments, respectively. The difference in mean breast-height diameter, however, was significant at age 26, and this was confirmed by a significant difference in a repeated measures analysis of annual diameter data for these treatments (P < 0.0001). Projection to age 30 revealed that both stand volume and value would be significantly higher in the thinned treatment by margins of 8.7 m3 ha-1 and $2457 ha-1. Regression analysis of soil data within the observed rooting depth of the trees from this stand indicated that nitrogen mineralization index, bulk density, sand percentage of the fine soil fraction, and percentage of oxidized sandstone in the soil profile were the most important variables in determining the stand's productive capacity (R2 = 0.7174). It was also found that of the five different spoil types encountered in the stand, the oxidized sandstone spoil had the most favorable physical and chemical properties for tree growth. Common root-restricting layers were found to have high soil density or increased levels of soluble salts. It has been shown that reclaimed surface mines can grow productive forests if the appropriate spoil materials are returned to the surface in sufficient depth. It has also been shown that surface mined lands reclaimed to pasture can be successfully reforested using silvicultural treatments to ameliorate unfavorable conditions for tree establishment and growth, though these treaments may not be cost-effective, and the success of these treatments was variable based on the soil characteristics of each site. / Master of Science
50

Procerum root disease physiology and disease interactions with ozone

Carlson, Jodi A. 02 March 2006 (has links)
Procerum root disease of eastern white pine (Pinus strobus L.), caused by Leptographium procerum (Kendr.) Wingf., has been epidemic in Virginia Christmas tree plantations since 1990. Symptoms of chlorosis, wilt, and decreased apical growth resemble those of water stress. Resin infiltration of the xylem at the stem base may be responsible for vascular occlusion leading to severe water deficits and mortality. The pathogen has been isolated from the roots of ozone-sensitive eastern white pines in the field, although not from nearby tolerant trees, and it may be that ozone sensitivity predisposes the trees to infection. The objectives of my Studies were to investigate the physiology of diseased white pines, and to determine the effects of ozone fumigation on disease development. Impacts of vascular occlusion upon host water relations and gas exchange were investigated in 8-yr-old, plantation-grown, white pine Christmas trees. Disease severity was estimated as the proportion of resin-soaked cross-sectional area at the base of the stem. The linear response of a suite of six physiological variables to disease severity was highly significant. Individually, the variables pre-dawn water potential, daily change in pre-dawn to mid-day water potential, stomatal conductance, and photosynthetic and transpiration rates all decreased significantly with increasing disease severity. Fumigation studies were conducted on white and loblolly (P. taeda L.) pine seedlings to determine if ozone exposure increased the incidence of root disease or the amount of stem tissue colonized by L. procerum. Roots were inoculated by soil drenching with conidial suspension, and stems were wounded at the base and inoculated with mycelium. Beginning 24 h post-inoculation, and for 14 consecutive days, seedlings were fumigated in closed chambers with charcoal-filtered air or 200 ppb ozone for 5 h/day, then removed to a charcoal-filtered greenhouse. Six weeks post-inoculation, root and stem tissue were plated on a medium selective for L. procerum. Ozone treatment did not significantly affect the proportion of diseased roots per seedling or the vertical colonization of stem tissue in seedlings of either species. / Ph. D.

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