To see the other types of publications on this topic, follow the link: Spruce seedling.
Dissertations / Theses on the topic 'Spruce seedling'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Spruce seedling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Pauliukevičiūtė, Grybauskienė Vilda. "Irrigation Scheduling for Norway Spruce (Picea abies (L.) Karst.) Seedlings." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20110908_114726-07715.
Full textAbstract:
The objectives of the thesis: • to analyse evapotranspiration of Norway spruce seedlings in irrigated and non-irrigated fields by applying lysimetric method; • to determine crop coefficient of spruce seedlings; • to measure dynamics of soil humidity during vegetation period; • to determine influence of irrigation regime on qualitative indices of spruce seedlings; • to determine optimal irrigation regime; • to set economic advantage of irrigation of Norway spruce seedlings.<br>Darbo uždaviniai: • ištirti paprastosios eglės sodinukų suminį išgaravimą drėkinamuose ir nedrėkinamuose plotuose lizimetriniu metodu; • nustatyti eglės sodinukų biologinius koeficientus; • įvertinti dirvožemio drėgmės dinamiką vegetacijos laikotarpiu; • nustatyti drėkinimo režimo įtaką eglės sodinukų kokybiniams rodikliams; • nustatyti optimalų drėkinimo režimą; • nustatyti paprastosios eglės sodinukų drėkinimo ekonominį efektyvumą.
2
White, Helen Marie. "Biotic and Abiotic Factors of Picea rubens (Red Spruce) Seedling Regeneration in Disturbed Heathland Barrens of the Central Appalachians." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/101088.
Full textAbstract:
During the late 19th and early 20th centuries, extensive logging reduced the forests of red spruce (Picea rubens) by nearly 99% through portions of West Virginia. In the wake of this disturbance, red spruce has begun regenerating on the ridge and mountaintop areas of Canaan Valley, West Virginia, where heath and grassland communities have both persisted in natural barrens and expanded into formerly forested areas. To understand abiotic and biotic conditions guiding the advance of the red spruce stand, I conducted a broad-scale assessment of thirty-one demographics plots spread across two sites (north Cabin Mountain and Bear Rocks/Dolly Sods), and a more focused assessment of red spruce species associations within thirty-two paired plots at Cabin Mountain. At the 15m x 15m demographics plots, I conducted a count of all P. rubens present, measured specimen height, DBH or diameter at ground level (DGL) for specimens < 1.37m tall, and assessed the relative percent cover of rock, shrub, herbaceous, and tree cover. These data, along with additional abiotic components derived from a DEM, formed the basis of my assessment using a generalized linear mixed model (GLMM) to identify the most significant biophysical variables related to P. rubens count. In the paired plots, I used the relative interactions index (RII) to compare the total cover of each present non-graminoid vascular species and the grouped cover types Rock, Graminoid, Lichen, Litter, and Moss in one 45cm-radius plot with a < 1.37m P. rubens specimen, and one paired 45cm-radius plot in open heath. The significance of differences in total cover were assessed with the Wilcoxon test and Tukey HSD. The GLMM identified percent rock cover and distance from the nearest P. rubens stand to be important correlates of P. rubens count at the demographic plots. Graminoid cover was found to be higher in P. rubens 45cm-radius plots than in paired heath plots, and Vaccinium angustifolium cover was found to be concentrated in 45cm radius plots beyond the first 15cm from the P. rubens stem. These findings reinforce a complex interplay between both the biotic and abiotic characteristics of a microsite and the successful germination and regeneration of a red spruce seedling in the heathland.<br>Master of Science
3
Roberts, Jessica Jaye Edna. "Incorporating low relative humidity and low temperatures into tree nursery growing regimes, effects on white spruce seedling growth, morphology and physiology." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ34408.pdf.
Full text
4
Blomqvist, Göran. "De-icing salt and the roadside environment : Air-borne exposure, damage to Norway spruce and system monitoring." Doctoral thesis, KTH, Civil and Environmental Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3140.
Full textAbstract:
<p>After decades of investigation, we still have to deal withthe problem of environmental effects of the use of de-icingsalt on roads. Lacking useful indicators of the system, westill do not know the environmental utility of ameliorativemeasures taken. The thesis aims at</p><p>i) describing the system of de-icing practices and theirenvironmental effects with special reference to the exposure ofthe roadside environment to air-borne salt and damage to Norwayspruce seedlings and ii) at proposing indicators for afollow-up system. By collecting bulk deposition and relatingthe deposition pattern to factors concerning wind androad-maintenance characteristics, the influence of thesefactors on air-borne exposure is investigated. By exposingNorway spruce (<i>Picea abies</i>(L.) Karst.) seedlings to roadsideconditions the influence ofsalt exposure on the degree ofdamage is investigated. Based on a comparison of severalsystems of monitoring, improvements are suggested by proposingnew indicators for salt use and its environmental effects.</p><p>A large part of the salt that is applied on the road surfacewill be transported by air and deposited on the ground in theroadside. While the vast majority of the salt will be depositedwithin some tens of metres of the road, some may still be windtransported several hundred metres away. The wind directionplays an important role for the deposition already at adistance of some ten metres from the road. Wind speedinfluences the distance to which the salt is transported.Chloride concentration in unwashed needles collected after thesalting season is positively related to the bulk deposition ofCl during the exposure. The degree of damage can be describedby a sigmoid curve of response to the Cl concentration inneedles. Improvements to the follow-up system are suggested byproposing indicators of the driving forces, pressures, states,impacts and possible responses as regards the undesired impactson water resources, vegetation and the roadside scenery as asocietal asset.</p><p><b>Keywords:</b>road, de-icing salt, air-borne, environmentalimpact, vegetation damage, Norway spruce, seedling, follow-up,monitoring, indicator</p>
5
Holm, Boris. "Effekter av superabsorbent på granplantors överlevnad och tillväxt." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-33386.
Full textAbstract:
Denna studie beskriver effekterna beträffande överlevnad och tillväxt hos gran (Picea abeis L. Karst) vid tillsats av superabsorbent Luquasorb 1280R i samband med plantering under olika betingelser. Plantor i form av täckrot och barrot studerades. Tillsats av superabsorbent visade sig ha en positiv inverkan på de studerade parametrarna i jämförelse med referensmaterial utan tillsats av superabsorbent. Detta visade sig särskilt vid extremförsök under tak utan tillgång till vattentillförsel under försöksperioden, förutom vattentillsats i samband med plantering.<br>This study describes the effects concerning survival and growth of Norway spruce seedelings (Picea abeis L. Karst) by addition of superabsorbent Luquasorb 1280R in connection with planting under differnt conditions. Container seedlings and bare-root seedlings were studied. The addition of superabsorbent showed a positive influence regarding the studied parameters in comparision with reference material without the addition of superabsorbent. This was most obvious at the the extreme test under roof without access to additional water during the test period, except water added in connection with planting.
6
Bakke, Olaf Andreas. "Jack pine (Pinus banksiana Lamb.) pollen effects on jack pine and black spruce (Picea mariana (P. Mill.) B.S.P.) seed germination and seedling growth." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ42997.pdf.
Full text
7
Verbauskas, Žydrūnas. "Biohumuso įtaka paprastosios eglės sėjinukų augimui." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140616_132652-51294.
Full textAbstract:
Magistro baigiamąjame darbe tiriamas biohumuso poveikis paprastųjų eglių (Picea abies (L.) Karst.) sėjinukų augimui atvirame grunte.
Tyrimo objektas - vienerių metų paprastosios eglės sėjinukai.
Tyrimų tikslas: nustatyti ekologiškos organinės trąšos - biohumuso įtaką paprastosios eglės sėjinukų augimui, vystymuisi, išlikimui, išeigai iš ploto vieneto, ekonominiam efektyvumui.
Tyrimo metodai. Loginė mokslinės literatūros apžvalga, apskaitos aikštelių ir duomenų statistinio apdorojimo metodai.
Darbo uždaviniai. Nustatyti biohumuso įtaką paprastosios eglės vienmečių sėjinukų augimui ir vystymuisi. Įvertinti vermikomposto įtaką sėjinukų išlikimui ir išeigai iš ploto vieneto. Atlikti biohumuso panaudojimo ekonominį įvertinimą.
Darbo rezultatai. Paprastosios eglės vienamečių sėjinukų antžeminės dalies augimą, iš šešių tirtų biohumuso normų, labiausiai įtakojo 20 t/ha norma. Ji esmingai padidino sėjinukų aukštį, spyglių skaičių ir jų ilgį, o jos poveikis sėjinukų skersmeniui, šoninių ūglių skaičiui bei jų ilgiui, šoninių pumpurų skaičiui buvo analogiškas kaip ir mineralinių trąšų.
Lyginant sėjinukų šaknų sistemas, biohumuso 10, 20 ir 30 t/ha normos patikimai padidino eglaičių pagrindinės šaknies ilgį (labiausiai – 20 t/ha), o pirmos eilės šoninių šaknų skaičių teigiamai įtakojo tik biohumuso 20 t/ha norma, palyginti su mineralinėmis trąšomis.
Efektyviausiai sėjinukų bendrąją, antžeminės dalies ir šaknų masę padidino biohumuso 20 t/ha norma. Be to, biohumusas labiau skatino... [toliau žr. visą tekstą]<br>The effect of biohumus on the growth of the seedling of Norway spruce in the open soil is researched in this master thesis.
The object of the research – the one year old seedling of Norway spruce.
Research aim is to test the influence of biohumus on the growth, development, survival, amount of the seedling of Norway spruce from 1 hectare and its economikcal effect.
Research methods. The review of logical scientific literature, the methods of statistic analysis of the data of the examined areas.
Research objectives. To define the influence of biohumus on the growth and development of one year old seedling. To assess the influence of vermicompost on the seedling survival and harvest from one hectare. To perform the economical evaluation of the use of biohumus.
Research results. The growth of a year old seedling from the six tested norms with biohumus was mostly influenced by 20 t/ha norm. It eesentially encreased the height of the seedling, the number and length of the needles. Its effect on the widh of the seedling, the number of the side branches, their length and the amount of the side buds was equivalent to the mineral fertilizers.
By comparising the systems of the roots, the norms of biohumus 10, 20 and 30, evidentally encreased the length of the main roots of the Norway spruce (mostly 20 t/ha). However, the number of the side roots of the first row was positively effected only by the 20 t/ha norm if compared to the mineral fertilizers.
The whole weight of the... [to full text]
8
MacDonald, G. Blake. "Comparative responses of black spruce and jack pine seedlings to interspecific competition." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30617.
Full textAbstract:
Competition from non-crop vegetation decreases the productivity of conifer plantations across Canada. The objectives of this research were: (1) to develop reliable indices of perennial, interspecific competition; (2) to compare the responses of black spruce and jack pine seedlings to tree and brush competition in northern Ontario; and (3) to identify the silvicultural implications of the responses.
An examination of potential components of a competition index considered measures based on hemispherical photographs, fractal geometry, stand maps, and mensurational data from 360 seedling-centred plots for each of the two crop species. Reliable competition indices should be simple formulations which include horizontal and vertical dimensions and which express the amount of competition relative to the size of the seedling. The optimum index was found to be the area of competing canopy on hemispherical photographs, relative to the seedling leaf area. An alternate index, requiring no elaborate equipment, was the sum of the competing stem volumes (relative to the seedling stem volume) of the largest competitor in each quadrant surrounding the seedling.
Comparisons of crop tree responses were made using functional growth analysis, replacing the conventional time axis with a competition axis. The relationship between growth and competition was adequately modelled with a power exponential composite function. Jack pine and bare root stock of both species maintained superior growth despite greater sensitivities to competition, compared to black spruce and container stock, respectively. Thus, jack pine or bare root stock of black spruce would outperform the alternatives if tending were delayed, but competition should be removed in all cases to capture the maximum growth potential. The rate of growth decline in response to competition was consistently greatest at the lowest competition levels, indicating that no beneficial effect on growth was provided by a light cover of non-crop vegetation.
Allometric analyses indicated that black spruce had a greater morphological plasticity than jack pine. At high competition levels black spruce allocated more biomass to branches and foliage, at the expense of stem and roots. Jack pine demonstrated no such adjustment in allocation pattern, but followed a strategy of stress avoidance through sustained high growth rates.<br>Forestry, Faculty of<br>Graduate
9
Löwbeer, Emma, and Erik Åkesson. "Detection and tracking of spruce seedlings in spatiospectral images." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-170082.
Full textAbstract:
I projektet detekteras och följs granplantor i spatiospektrala bilder för att därefter skapa en hyperspektral datakub för av varje gran. För att detektera granarna prövas fyra metoder: manuell detektion, detektion med segmentering, detektion med SVM och detektion med neuralt nätverk. Minnesanvändning och körningstid jämförs mellan två implementationer, där hyperspektral rekonstruktion görs med olika metoder.
10
Heineman, Jeanette Lynne. "Growth of Interior spruce seedlings on forest floor materials." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29871.
Full textAbstract:
On a site with a high water table and thick forest floor near Smithers, B.C., two year-old Interior spruce (Picea glauca (Moench) Voss X Picea engelmanni Parry) container seedlings were outplanted onto mineral soil, H-layer material, F-layer material, and rotten wood. Large and small screef sizes were utilized. Temperature and volumetric water contents of the various substrates were monitored over the 1989 growing season, and fertilization with NH₄NO₃ was carried out at the beginning of the 1990 growing season. Destructive sampling of the seedling population took place in August 1989 and August 1990 in order to determine height, root collar diameter, root mass, shoot mass, total seedling mass, and shoot to root ratio. Foliar N concentrations were also determined in late August 1990.
Differences in height and diameter for the seven screef size/substrate treatments were not significant, but the organic substrates produced seedlings of greater root, shoot, and total seedling mass than did mineral soil. Greater seedling mass was correlated most strongly with higher substrate temperature, and to a lesser extent with lower soil moisture content, as well as with higher foliar N concentration. There were no significant differences in survival between the treatments. Seedlings growing in the organic substrates had higher foliar N levels, and fertilization improved growth for all parameters.
It is concluded that on sites such as this, better growth results can be achieved by planting Interior spruce seedlings high above the water table in F-layer material, where conditions are warmer and drier, than by making deep screefs down to more traditionally acceptable planting substrates such as mineral soil or even the well decomposed H-layer material.<br>Forestry, Faculty of<br>Graduate
11
Lehto, Tarja Helena. "Role of mycorrhizas in drought resistance of Sitka spruce seedlings." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/11045.
Full text
12
Cook, Paul Andrew. "Effect of the spruce root aphid, Pachypappa vesicalis on the growth and physiology of Sitka spruce seedlings." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337573.
Full text
13
Harper, George James. "The effect of cold storage duration and soil temperature on the photosynthetic ability of Picea glauca seedlings." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28774.
Full textAbstract:
In response to concern over the failure and poor growth of many interior and white spruce plantations in British Columbia the effect of storage duration and soil temperature on the photosynthetic ability of white spruce seedlings was explored. Seedlings of Picea glauca were dark freezer stored (-5°C) from 9.6 to 30.6 weeks, thawed and grown for 28 days in a growth chamber at three different soil temperatures (3,7,11°C). During this period gas exchange variables and chlorophyll fluorescence kinetics were followed.
Seedlings stored for periods of 22 weeks or longer had significantly lower rates of photosynthesis dependent on the outplanting soil temperature. Stomatal conductance was initially low upon outplanting and showed a recovery period of 4-7 days duration. The level of stomatal conductance increased in seedlings after they were stored for 26.1 weeks or longer. Chlorophyll fluorescence measurements of seedlings stored from 22 to 30.6 weeks showed a recovery period in photosynthetic efficiency (Fy/Fp) related to changes in photosynthesis. A decrease in seedling Fy/Fp with increasing periods of storage was noted at day 5 after outplanting. A disproportionate increase in new root growth with the increasing soil temperatures, measured after the 28 day growth period, suggested a soil temperature threshold for root growth exists between the 7°C and ll°C. In contrast, the stomatal conductance and photosynthesis results suggest the seedling shoots were not directly affected by the cold soil temperatures. In general, the results suggest Picea glauca seedlings stored longer than 22 weeks in freezer conditions have reduced photosynthetic ability, root growth and overall vigor. Fluorescence and bud break data suggest the reduction was possibly due to freezing damage sustained in storage affecting photosynthetic electron transport through photoinhibition upon returning seedlings to the light.<br>Forestry, Faculty of<br>Graduate
14
Stattin, Eva. "Root freezing tolerance and storability of Scots pine and Norway spruce seedlings /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5639-8.pdf.
Full text
15
Kaul, Sonu. "Uptake, transport and bioactivity of exogenously applied ABA and ABA analogues in white spruce and wheat seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36644.pdf.
Full text
16
Wallertz, Kristina. "Pine weevil feeding in Scots pine and Norway spruce regenerations /." Alnarp : Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200960.pdf.
Full text
17
Shishido, Masahiro. "Plant growth promoting rhizobacteria (PGPR) for interior spruce (Picea engelmannii x P. glauca) seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25159.pdf.
Full text
18
Wang, Yingfang. "Low temperature effects on physiological characteristics of dormant white spruce (Picea glauca) bareroot seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34854.pdf.
Full text
19
Hu, Yuebing. "Effects of herbicide, glyphosate, application on growth of planted black spruce, Picea mariana, seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0015/MQ53105.pdf.
Full text
20
Redfield, Edmund Bancroft. "Tolerance mechanisms of black spruce, Picea mariana, seedlings exposed to saline oil sands tailings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60488.pdf.
Full text
21
Caza, C. L. (Caroline Louella). "The ecology of planted Engelmann spruce (Picea engelmannii Parry) seedlings on subalpine forest cutovers." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30967.
Full textAbstract:
At high elevations in south-central British Columbia conifers are slow to re-establish after logging and the vegetation on many harvested sites is dominated by herbs and shrubs. At present, Engelmann spruce (Picea engelmannii Parry) is widely planted on subalpine cutovers to increase stocking levels, but the growth and survival of planted seedlings is often poor and is highly variable. The objectives of this research were to study: 1) variation in the environments within which Engelmann spruce establishes on subalpine cutovers; 2) the performance of planted seedlings in these environments both with and without interference from non-crop species; 3) the relationship between the growth of planted seedlings and naturally established Engelmann spruce and; 4) the responses of non-crop species to post-logging disturbances.
Engelmann spruce seedlings were planted in 1987 into patches of herbs and shrubs and on skid trails on two subalpine cutovers that were winter-logged in 1983. Seedlings grew poorly beneath canopies of all non-crop species where low light levels were a dominant factor limiting growth despite differences between patch types in other environmental factors. Differences in light availability between patches were associated with a relatively greater impact of herbs on stem diameter and lateral growth and of shrubs on height growth.
The removal of non-crop species increased light levels and soil temperatures and resulted in significantly greater growth and ratios of shoot:root biomass in open-grown seedlings. Increases in the size or number of most components in open-grown seedlings were strongly correlated. Needles, however, responded differently to treatments than other seedling components. Increases in shoot:root ratios were size-related and due to differences in the relative growth rates of roots and shoots. There was no evidence of shifts in carbon allocation within seedlings in response to variation in resource availability.
There were significant differences between the characteristics of planted and naturally established Engelmann spruce seedlings. Open-grown planted seedlings were larger than naturals of the same age and had higher relative growth rates, but similar ratios of needle:stem biomass. Shaded planted seedlings were also larger than naturals but had lower relative growth rates and lower ratios of needle:stem biomass. There were also differences between naturals and planted seedlings in the morphology of root systems.
After the removal of above-ground vegetation, dominant herbs re-established cover within one season, mainly from persistent below-ground structures. Dominant shrubs recovered more slowly but were not replaced by new species, even after the removal of both above- and below-ground biomass. Shifts to new dominants occurred after the removal of total biomass in herb patches and also in undisturbed herb patches. Species shifts in undisturbed herb patches as well as increases in total cover in both herb and shrub patches over the study period suggested that the plant communities on the study sites were not at equilibrium.
The results of this research indicated that shifts in carbon allocation within seedlings are not part of Engelmann spruce's strategy for establishment in heterogeneous subalpine environments. It is suggested that patterns of growth are conservative rather than competitive and that increased levels of resources must be delivered directly to seedlings to improve early performance. The removal of non-crop vegetation is one way to do this but dominant non-crop species, particularly herbs, will re-establish rapidly relative to the rate of spruce establishment, suggesting limited benefits from vegetation management on subalpine cutovers. Any form of harvesting that causes mimimum understorey disturbance on these sites will result in levels of spruce regeneration that fail to meet current stocking standards. Planting large and vigorous seedlings in areas where resources are high and interference is low may alleviate this problem, but changing silvicultural expectations to better reflect the constraints on conifer regeneration in subalpine environments may be a more effective solution.<br>Forestry, Faculty of<br>Graduate
22
Petersson, Magnus. "Regeneration methods to reduce pine weevil damage to conifer seedlings /." Alnarp : Southern Swedish Forest Research Centre, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/s330.pdf.
Full text
23
Nemu, Tajure N. "Effects of post-hardening fertilization on early growth and nutrition of planted black spruce seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0002/MQ29459.pdf.
Full text
24
El-Hallak, Mona. "Nutrient and carbon loading of black spruce containerized seedlings during nursery culture and early outplanting." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ53451.pdf.
Full text
25
Silim, Salim Nahdy. "Regulation of cold hardiness in seedlings of western red cedar, yellow cedar and white spruce." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31514.
Full textAbstract:
The development and nature of cold hardiness was examined in first-year seedlings of the three conifer species: western red cedar (Thuja plicata Donn) from southern Vancouver Island, yellow cedar (Chamaecyparis nootkatensis (D. Don) Spach) from northern Vancouver Island and white spruce (Picea glauCa (Moench) Voss) from northern interior of British Columbia. The relationship between free thiols and the development of cold hardiness, and the effects of mefluidide on the induction of hardiness in the three species were also examined. To permit an accurate estimation of cold hardiness, a reliable method of determining hardiness based on the electrolyte conductivity method (EC) was developed for the three species.
Optimization of tissue preparation resulted in accurate and reliable estimates of cold hardiness in the three coniferous species. A comparison of visual assessment of shoot damage with the results obtained by the EC method indicated that the two methods were highly correlated although the EC method slightly overestimated the temperature at which 50% of the samples were killed (LT₅₀). The absolute lethal temperature (LT₁₀₀) estimated by the EC method was lower (3 to 7 °C) than that determined by the visual method.
The development of hardiness in the three species was characterized by different mechanisms: in white spruce it was initiated by short photoperiod, in red and yellow cedar it was basically regulated by low temperature. Low temperature (7/3 °C day/night) increased hardiness in all three species but subfreezing temperature (2/-3 °C day/night) increased the rate of hardening only in the two cedars. Furthermore, white spruce seedlings were apparently able to attain extreme levels of hardiness (below -65 °C) without exposure to temperatures below 0 °C. The ability to deharden in white spruce
was related to the satisfaction of chilling requirements while red and yellow cedar seedlings appeared to deharden only in response to warm temperatures.
Mefluidide (0.1 and 0.4 mg l⁻¹ ) applied as a root drench did not increase cold hardiness in any of the three species. Stomatal conductance was however decreased, thus resulting in increased shoot water potentials. Net photosynthesis was reduced predominantly due to stomatal limitations. Mefluidide increased synthesis of ABA in shoots of seedlings of the three species. The level of tissue ABA, like the other variables, was dependent on mefluidide concentration.
Low temperature (7/3 °C day and night, 9 h photoperiod, 250 μmoles m⁻² s⁻¹, 400 - 700 nm) induced an increase in free thiols (predominantly reduced glutathione) which was accompanied by an increase in hardiness. Although short photoperiod at a warm temperature (9 h, 20/15 °C day and night) increased hardiness in seedlings of white spruce, no significant increase in thiols was observed. Root application of buthionone sulfoximine and dichlormid affected tissue glutathione levels but these changes did not result in significant changes in freezing resistance. There appears to be no relationship between glutathione and freezing resistance.<br>Forestry, Faculty of<br>Graduate
26
Langvall, Ola. "Interactions between near-ground temperature and radiation, silvicultural treatments and frost damage to Norway spruce seedlings /." Alnarp : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/s140.pdf.
Full text
27
Falls, Robert William. "Cambial and photosynthetic activity relations in untreated, wounded, and geotropically stressed white spruce (Picea glauca (Moench.) Voss) seedlings." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30580.
Full textAbstract:
This thesis reports results of a study of relationships between photosynthetic activity and developmental parameters, and cambial activity (wood formation rate), during and following the period of active wood formation in untreated white spruce seedlings, and in seedlings stressed either by extensive stem incisions, or by tilting.
The approach involved the use of two non-destructive methods for measuring photosynthetic activity: chlorophyll a fluorescence using optical instrumentation, and CO₂ uptake using infrared gas exchange techniques. Photosynthetic development was examined by estimating chlorophyll a content from a specific fluorescence parameter (O-level), and by the relative occurence of specific chloroplast stroma and membrane (thylakoid) proteins using electrophoretic and immunoblotting techniques. Cambial activity was determined using digitized image analysis of prepared cross-sections of seedling stems.
Several fluorescence parameters were strongly correlated to cambial activity in untreated seedlings during the period of active wood formation (in mid-summer). However, the correlations were severely diminished or non-existent when cambial activity was arrested (in late-summer and autumn). Correlations between fluorescence and cambial activity in stressed seedlings were not discernible at any time, suggesting that the induced stresses resulted in a substantial alteration in normal source:sink relationships. Carbon dioxide uptake measures, either uncorrected or corrected to estimated chlorophyll α content, were not measurably correlated to cambial activity in untreated or stressed seedlings at any time in this system.
Chlorophyll α content estimated from O-level fluoresecence, was not related to cambial activity in untreated or stressed seedlings. The relative occurences of two enzymes and proteins associated with photosynthetic carbon fixation, i.e. ribulose 1,5-bisphosphate carboxylase (Rubisco) and Coupling Factor, did not appear to be influenced by applied wounding and geotropic stresses.
In contrast to the strong correlations found between fluorescence parameters and current season stem vigour, pre-season seedling height and cross-sectional stem areas were not related to stem vigour. These results suggest that in unstressed white spruce seedlings, the measure of specific chlorophyll α fluorescence parameters, using the methods
delineated in this study, offers an alternative and more strongly predictive means of assessing current stem vigour, than measures of seedling dimensions.
The results of this study provide strong evidence for, and a degree of elucidation on, the anticipated but previously unestablished existence of a source:sink relationship between leaves and vascular cambium in conifer seedlings. This information should provide an initial foundation for the elucidation of non-invasive methodologies by which to assess stem vigour of white spruce seedlings, and to probe source:sink relationships in other conifer species.<br>Science, Faculty of<br>Botany, Department of<br>Graduate
28
O'Brien, Cristin L. "Revegetating Blackwoods Campground, Acadia National Park: Emphasis on Natural Regeneration of Red Spruce and Balsam Fir." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/ObrienCL2005.pdf.
Full text
29
Šilingienė, Gerda. "Influence of damp water steam on norway spruce (Picea abies (L.) H. Karst.) seeds, seedlings and crop weediness." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2013~D_20140123_133607-54891.
Full textAbstract:
Ecologization of agriculture and forestry directly and indirectly influences the environment, water, air, and landscape. Thus, analysis of organic forestry activities, evaluation and forecast are of scientific, ecological and political significance. Weed control and the resulting organic farming and forestry issues have attracted greater attention to the use of physical methods in weed control, because this weed control method is effective and does not leave chemical residues neither in the soil, nor in water. One of the physical methods is thermal weed control method, which contrary to the other weed control methods, leaves only dead biomass, preventing self-sowing of weed seeds in the soil, destroys some of the pests and disinfects the surface layer of soil (Upadhyaya et al, 2007). Meanwhile, as an alternative to seed treatment, various physical methods are also used (Lynikienė, 2006). However, the effect of some of the techniques on seed-born fungi are not explained, optimal exposures of the effects are unidentified (Clear et al., 2002). One of the possibilities to reduce the infestation of seeds by fungi - their thermal destruction.<br>Žemės ir miškų ūkio ekologizavimas tiesiogiai ir netiesiogiai veikia aplinką, vandenį, orą, landšaftą. Todėl ekologinės veiklos miškų ūkyje analizė, įvertinimas ir prognozė turi mokslinę, ekologinę ir politinę reikšmę (Diepenbrock, 1996). Piktžolių naikinimas ir ekologinės žemės bei miškų ūkių problemos paskatino atkreipti dėmesį į fizikinių metodų naudojimo piktžolių kontrolei svarbą, nes šis piktžolių naikinimo metodas yra efektyvus, nepaliekantis cheminių medžiagų likučių nei dirvožemyje, nei vandenyje. Vienas iš fizikinių metodų ir yra terminis piktžolių naikinimo būdas, kuris, skirtingai nuo kitų piktžolių kontrolės būdų, palieka tik negyvą jų biomasę, neleisdamas piktžolių sėkloms pasisėti dirvoje, sunaikina kai kuriuos kenkėjus ir dezinfekuoja paviršinį dirvožemio sluoksnį (Upadhyaya, 2012). Kaip alternatyva sėkloms beicuoti taip pat naudojami įvairūs fizikiniai metodai (Lynikienė, 2006). Kai kurių metodų poveikis sėklomis plintantiems mikromicetams nenustatytas, nenustatytos ir šių poveikių optimalios ekspozicijos (Clear et al., 2002). Viena iš galimybių sumažinti sėklų užterštumą mikromicetais – jų naikinimas termiškai.
30
Kännaste, Astrid. "Volatiles of Conifer Seedlings : Compositions and Resistance Markers." Doctoral thesis, KTH, Organisk kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4723.
Full textAbstract:
Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (“mini”) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. Thus, it has been proposed that planting young conifer seedlings in clear-cut areas may reduce the damage caused by pine weevils. In attempts to determine why mini seedlings appear to be less damaged by pine weevils than “conventional” seedlings, the volatiles released by Norway spruce and Scots pine mini seedlings were investigated, since such chemicals are of great importance in herbivore-plant communication, inter alia acting as repellents, attractants or antifeedants. Volatiles from the seedlings were collected, separated and identified by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry. The results show that there are high levels of chemodiversity among both spruce and pine seedlings. Between-tissue and age-related variations in their emissions were also found. Norway spruce clones infested by mites were also examined to assess genotype- and pest-specific stress reactions of Norway spruce. Finally, the effects of certain spruce defense compounds on the behavior of the large pine weevil Hylobius abietis were examined.<br>QC 20100818
31
Bertin, Sophie. "Physiological ecology of understorey trees in low impact silvicultural systems." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3773.
Full textAbstract:
Continuous cover forestry (CCF), an alternative forest management approach to clearfelling, is increasingly being adopted in the UK. It aims at enhancing stand structural diversity and favouring natural regeneration and subsequent seedling growth below the existing canopy of plantation forests. One area of limited knowledge is the critical level of below-canopy light for the growth of naturally regenerating seedlings. In addition, plant growth beneath canopies is influenced by other factors (e.g. herbivory). Picea sitchensis (Bong.) Carr. (Sitka spruce) seedlings under canopies have been observed to be severely damaged by Elatobium abietinum (Walker) (green spruce aphid) attacks. The combined effects of light availability and insect attack on seedling growth are not well understood, however, this understanding is crucial in order to ensure successful management of regeneration within CCF systems. A controlled experiment, which mimicked different natural understorey light levels along with repeated artificial aphid infestation, was conducted over two years to look at seedling performance through structural and physiological (chlorophyll fluorescence) measurements. Aphid population assessments showed significant increased population density under shaded conditions. Nevertheless, aphid impacts were mainly localised in extent while the impact of light was the major component that described seedling growth. Light was the primary factor affecting the whole-plant biomass, whereas aphids had only localised effects on the total dry weight of older needles and roots, and on leader extension growth. A significant interaction between light levels and presence/absence of aphid infestation was found for main leader extension growth of the seedlings during the second year of the experiment, with lower values at low light levels under infestation. Plant biomass allocation was affected strongly by light, while aphid presence did not result in significant changes. At the leaf physiologylevel, the light environment was found to be the main driving factor affecting photosynthetic response, whilst aphid presence had only a short-term localised effect on photosynthesis. The impact of light levels and aphid presence on seedling growth were also determined at an experimental field site where plots were located across two light regimes typical of CCF conditions in upland UK coniferous forests. The comparison of the photosynthetic response of the seedlings in both the controlled and field experiment highlighted the importance of considering the temporal heterogeneity of the light environment experienced by understorey seedlings in CCF stands, while aphid and aphid x light interaction effects could not be determined due to very low aphid levels during the year. Finally, a pre-existing light model was parameterised to predict the understorey light environment required to promote successful seedling growth in CCF stands. Sensitivity and validation analyses were also performed.
32
Randhawa, Nirmal Singh. "Impact of fertilization and vegetation management on growth and nutrition of white spruce seedlings and related soil nitrogen transformations." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0003/MQ29460.pdf.
Full text
33
Malik, Vikram Singh. "Growth and nutrient dynamics of nutrient-loaded black spruce seedlings in relation to neighbouring vegetation on boreal mixedwood sites." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq41467.pdf.
Full text
34
Klinka, Karel. "Survival and growth of western larch seedlings in relation to light availability." Forest Sciences Department, University of British Columbia, 1997. http://hdl.handle.net/2429/651.
Full textAbstract:
Western larch (Larix occidentalis Nutt.) is an important component of the montane forest in southeastern British Columbia. It grows in cool-temperate (IDF and ICH zones) and boreal climates (MS zone and, occasionally, ESSF zone). Larch is considered a very shade-intolerant species which can tolerate low light (partial shading) only during the seedling stage (the first 5 growing seasons). Typically, it regenerates after fire in the open on seedbeds exposed by burning. However, to what extent it tolerates low light and how various light environments affect its survival and growth is not known. The objective of our study was to determine the variation in survival and growth of western larch seedlings in relation to light availability and site conditions.
35
Christiansen, Stowe Debra. "Morphological and physiological characteristics of air-slit containerized white spruce seedlings (1 + 0) in response to four different irrigation regimes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ60625.pdf.
Full text
36
Causse, Vincent. "The role of substrate characteristics in Populus tremuloides (MICHX.) seed germination in post-disturbance black spruce-feathermoss forest in northwestern Quebec /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100782.
Full textAbstract:
Trembling aspen (Populus tremuloides (Michx.)) has become established along a mining road in the lower northern Quebec region (49°39' to 49°45'N and 79°01' to 79°02' W) in areas that have not supported aspen in the past. The primary means of regeneration of aspen is through vegetative root suckers, but it is doubtful that it could progress through this region at such a fast rate solely by asexual reproduction. Aspen are known to produce large amounts of seeds that could account for aspen's rapid progression, but sexual reproduction of aspen is rare; very little is known about Populus tremuloides seed germination and seed survival in natural conditions. The aim of this study was to determine seedbed conditions that facilitate the emergence and survival of Populus tremuloides seedlings, and to identify the key factors involved in these processes. Observations of established saplings and a sowing experiment were conducted on both post harvest and post fire sites. Our data on established saplings showed that there were seed-origin trembling aspen located in both post-harvest and burned areas indicating that Populus tremuloides can and has established from seed in areas where aspen was previously absent. Both our sowing experiment and our greenhouse experiment showed that the emergence of seedlings was relatively low, but that Polytrichum strictum moss and exposed mineral soil depressions were the best seedbeds for seed germination. Extreme temperatures and availability of moisture appeared to be controlling factors on seed germination, but ultimately the physical and biological characteristics of each substrate influenced the substrate's response to these factors in a different way. We conclude that sexual reproduction of trembling aspen may and has occurred in this region, and is promoted by the presence of exposed mineral soil and Polytrichum strictum moss.<br>Keywords: Bryophytes, Populus tremuloides, Polytrichum, Sphagnum, seedling, seedbed, germination, seed.
37
Evans, Lynn Patricia. "The effects of increased atmospheric carbon dioxide on growth and morphology of seedlings of silver birch (Betula pendula Roth.) and Sitka spruce (Picea sitchensis (Bong.) Carr.)." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/14808.
Full textAbstract:
The objective of this study was to determine the effects of long-term exposure to elevated CO<SUB>2</SUB> on the growth and morphology of seedlings of Sitka spruce and silver birch, with a focus on the effects of elevated CO<SUB>2</SUB> on the expansion, surface characteristics, specific leaf area, anatomy and chlorophyll content of leaves of silver birch. Seedlings of Sitka spruce and silver birch were placed in pots in open top chambers receiving ambient or elevated CO<SUB>2</SUB>. After one growing season there was a significant increase in biomass production in seedlings of Sitka spruce grown in elevated CO<SUB>2</SUB> compared to those grown in ambient CO<SUB>2</SUB>, but after eighteen months this effect had disappeared. The initial increase in biomass was a result of a significant increase in root mass. At the end of the second growing season there was no effect of elevated CO<SUB>2</SUB> on allocation of dry mass. There was no effect of elevated CO<SUB>2</SUB> on total number of branches produced at the end of the second growing season but there was an increase in the rate of branch production. Nitrogen, phosphorus and potassium concentration of leaves was reduced in plants grown in elevated CO<SUB>2</SUB>. After one growing season biomass was increased in elevated CO<SUB>2</SUB> plants by <I>ca</I> 20%, rates of photosynthesis were also higher in elevated CO<SUB>2</SUB> plants. There was no effect of CO<SUB>2</SUB> treatment on root: shoot ratio. There was a significant increase in branch production in plants grown in elevated CO<SUB>2</SUB>, but despite an increase in leaf area production early on in the growing season, there was no difference in total tree leaf area at the end of the growing season. Nitrogen, phosphorus and potassium concentration of leaves was reduced in plants grown in elevated CO<SUB>2</SUB> and leaves on elevated CO<SUB>2</SUB> plants senesced <I>ca</I> one week earlier than leaves of plants grown in ambient CO<SUB>2</SUB>.
38
Krasowski, Marek J. "The development of roots and root systems in white spruce, Picea glauca (Moench) Voss, seedlings and the influence of cultural treatments on root morphology, anatomy, and the capacity to conduct water." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ37351.pdf.
Full text
39
Von, der Gonna Marc A. "First year performance and root egress of white spruce (Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta Dougl.) seedlings in mechanically prepared and untreated planting sport in North Central British Columbia." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27347.
Full textAbstract:
Root zone temperature and root egress were studied during the first growing season on white spruce and lodgepole pine seedlings planted in various forms of mechanically prepared microsites. Mounded microsites had higher summer soil temperatures and greater diurnal ranges, at a depth of 10 cm, than the patch and control treatments. Mounded microsites, however, showed the greatest response to changes in weather and decreasing solar radiation inputs in the fall, being the first to record soil temperatures below freezing.
Seedlings planted in the deep mineral soil over inverted humus mounds created by the Ministry Mounder had significantly greater numbers of new roots greater than 1 cm long than did seedlings planted in patch and control treatments at 45 and 70 days after planting. Seedlings planted in other mound and plowing treatments had high to intermediate numbers of new roots. At 95 days after planting, seedlings planted on all mounded treatments generally had higher root area indices, root dry weights and total dry weights than did seedlings on other treatments. Variation in treatment results over the three spruce sites studied reflect differences in site conditions, primarily soil moisture regimes. High and fluctuating water tables negatively affected seedlings planted in patch and control treatments.<br>Forestry, Faculty of<br>Graduate
40
Johansson, Anders. "Olika markberedningsmetoders effekt på granplantors (Picea abies) överlevnad och höjdtillväxt vid Siljansfors försökspark." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-70923.
Full textAbstract:
Markberedning är vanligt förekommande när återbeskogning skall ske efter en avverkning. Vilken metod som väljs styrs av olika faktorer som t ex markfuktighet, humuslagrets tjocklek och mineraljordlagrets djup. I detta arbete studeras ett försök vid SLU: s försökspark i Siljansfors, ca 20 km SV om Mora. Studien omfattar två olika försöksytor, Sf 284 och Sf 287, planterade med gran (Picea abies) år 2004 respektive 2007. Ståndorten är en moränmark, markfuktighetsklassen är frisk och vegetationstypen är blåbär- och lingontyp och är belägen cirka 210 m.ö.h. Syftet med denna studie är att utvärdera och jämföra tre olika markberedningsmetoder med avseende på överlevnad och höjdtillväxt hos granplantor (Picea abies) under de första åren efter plantering. Vid plantering utan markberedning och utan kemiskt behandlade plantor är risken för en hög avgång på grund av skador orsakade av snytbagge (Hylobius abietis L.) stor de första åren. De markberedningsmetoder som jämfördes var högläggning, fläckmarkberedning och inversmetoden. Dessa tre metoder jämfördes inbördes samt mot att inte markbereda alls. I det totala samlade plantmaterialet var hälften kemiskt behandlat mot snytbagge. Fördelningen kemiskt behandlat och obehandlat plantmaterial var jämt fördelat i alla försök och upprepningar. I studien ingick också en utvärdering av den så kallade ”kanteffekten”, dvs. effekten av att plantorna sattes närmare än, respektive längre än 10 cm från kanten av den anlagda markberedningsytan. I juli 2009 mättes planthöjd och överlevnad på försöksytorna. Resultatet presenteras som medelvärden i form av stapeldiagram. Överlevnadsgraden höjdes med hjälp av markberedning, permetrinbehandling och val av planteringspunkt i förhållande till humuskant. Det var framför allt högläggning och inversmarkberedning som gynnade plantornas höjdtillväxt.<br>Soil preparation is common when reforestation occurs after harvesting. Which method is chosen is governed by various factors such as soil moisture, humus layer thickness and depth of mineral soil. An experiment was made at SLU's experimental park in Siljansfors, about 20 km SW about Mora. The study comprises two different experimental areas, Sf 284 and Sf 287, where Picea abies was planted in 2004 and 2007 respectively. The soil is a moraine, the soil moisture class is fresh and the vegetation type is blueberry and lingonberry type. The site is located approximately 210 m above sea level. The purpose of this study was to evaluate and compare three different soil preparation methods regarding to survival and height growth of Picea abies during the first years after planting. In the case of planting without soil preparation and without chemically treated plants, the risk of a high mortality due to the damage caused by pine weevil (Hylobius abietis L.) is high during the first years. The soil preparation methods that were compared were mounding, patch scarification and the inverse method. These three methods were compared to each other as well as to no soil preparation at all. In the total aggregate plant material, half were chemically treated against pine weevil. The distribution of chemically treated and untreated plant material was evenly distributed throughout all trials and repeats. The study also included an evaluation of the so-called "edge effect", i.e. the effect of placing the plants closer than, respectively, longer than 10 cm from the edge of the scarified patch. In July 2009, plant height and survival were measured in the experimental areas. The result is presented as averages in the form of bar charts. The survival rate was increased by soil preparation, permetrin treatment and selection of planting point relative to humus edge. It was above all mounding and inverse soil preparation that favored the height of the plants.
41
Johansson, Karin Margareta. "Interactions between site preparation, seedling type and genetics on the establishment of Norway spruce." 2004. http://www.lib.ncsu.edu/theses/available/etd-05122004-140102/unrestricted/etd.pdf.
Full text
42
Bagherzadeh, Chaharjouee Ali. "Mechanisms of Carbon and Nitrogen transformations in Forest floors of Beech-, Spruce- and Mixed Beech-Spruce Stands." Doctoral thesis, 2004. http://hdl.handle.net/11858/00-1735-0000-0006-B108-0.
Full text
43
Binnie, Sheila Catherine. "Vegetative storage protein accumulation and physiological changes occurring within interior spruce seedlings." Thesis, 1993. http://hdl.handle.net/2429/1272.
Full textAbstract:
The appearance and accumulation of vegetative storage proteins in nursery-grown Interior spruce seedlings (Picea glauca and P.engelmanni complex) was evaluated along with changes in seedling physiology. The 30 kD and 27 kD vegetative storage proteins (VSP) appeared after vegetative maturity (budset) and accumulated during the development of rest and the acquisition of cold hardiness. This trend was observed in bud extracts of three seedlots QL, EK, and PG as well as in the ambient treatment (natural fluctuations in photoperiod and temperature) of seedlot FIN. Stem and root tissue had similar accumulation patterns. Cold hardiness levels were measured using the electrolyte leakage method. This test is used annually to predict lifting date for cold storage of seedlings. Both the LT₅₀ (temperature for 50% electrolyte leakage) and the index of injury at -18°C (I.I.@-18°C) were low during early fall when storage protein levels were negligible in seedlot QL extracts. Afterwards, hardiness (I.I.@-18°C) was acquired and VSP accumulated until late October. Scanning densitometry of SDS-PAGE gels indicated that 15% of total protein was VSP by early November. These changes were accompanied by a decline in photosystem II activity, mitotic index, and dormancy. In seedlot QL, vegetative storage protein patterns were correlated to LT₅₀ (r = -0.972), photosystem II activity (r = -0.971), index of injury at -18°C (r = -0.900) and days to budbreak (r = -0.893). Seedlings stored at 4°C showed a slight decline in VSP and a decrease in seedling quality after 6 months of storage. Fall acclimation treatments -- long day 16 hr, 10°C days/5°C night (LD/Cold), short day <12 hr, 22°C day/18°C night (SD/Warm), and Ambient treatment -- indicated that prolonged short days caused maximum VSP accumulation within 30 days whereas under ambient conditions it took between 80 to 100 days. Cold temperatures may help cause the normal gradual increase in VSP and cold hardiness within buds. The SD/warm root bark was not as strongly influenced by daylength as bud and stem tissue because VSP accumulation was gradual. Although SD/warm seedlings accumulated maximum VSP levels, these seedlings remained dormant and did not become cold hardy. The results indicate that VSP accumulation and cold hardiness usually develop in parallel but they are unrelated. Under normal fall acclimation conditions, VSP accumulation and cold hardiness acquisition patterns are very similar; therefore, both could be used to predict lifting date in the future, with VSP used to predict lifting date and hardiness testing used to ensure cold hardiness.
44
Kostamo, Markku J. "Performance of interior spruce seedlings planted under dry soil and climatic regimes." Thesis, 1997. http://hdl.handle.net/2429/6409.
Full textAbstract:
A soil water balance model was used in a retrospective study of the survival and performance of short-day treated interior spruce seedlings, operationally planted in the Prince George region under dry soil and climatic regimes in July and August, 1994. The soil water balance model has potential to be used in operational forestry as a tool in managing plantation sites that are susceptible to drought. Comparison of modeled and measured soil water content indicated that the model is able to predict soil moisture accurately if applied to sites where model assumptions are met. The model should be a good predictor of soil water content between early May and mid August for the Prince George region. A linear regression model was developed predicting seedling performance by soil moisture. The relationship between a seedling performance index and mean ϒm (soil matric potential) for 30 days following planting is strong, r²= 0.75. The best predictor of a root variable from above ground morphological measurements was found to involve a volume surrogate (caliper² x height) as the independent variable and dry root mass as the dependent variable, r² = 0.50. Site characteristics were found to be a good predictor of seedling survival, r²2 = 0.64. An additional seedling study showed that percent survival has a strong relationship with the modelled mean ϒ for 30 days following planting. Survival decreases substantially below a mean ϒm of -0.2 MPa.
45
"FERTILIZATION TO OPTIMIZE GROWTH OF TREE SEEDLINGS ON RECLAIMED OIL SANDS SITES." Thesis, 2014. http://hdl.handle.net/10388/ETD-2014-01-1368.
Full textAbstract:
Successful establishment of boreal tree seedlings like trembling aspen (Populus tremuloides Michx) and white spruce (Picea glauca (Moench) Voss.) in reclaimed oil sands mining sites is often limited by low nutrient availability and competition from the ground cover vegetation like planted cover crops and weeds. Competing vegetation can adversely affect seedling establishment by augmenting the impacts of moisture and nutrient stress. Despite high potential of barley (Hordeum vulgare L.) and oats (Avena sativa) as cover crops in oil sands reclamation, it was not well known how these crops interact with fertilization to influence early survival and growth of tree seedlings. This study evaluated the potential of fertilization and other silvicultural practices to improve revegetation success in oil sands sites reclaimed with peat-mineral mixture. Fertilizer application significantly increased height and root collar diameter (RCD) of tree seedlings in controlled environment greenhouse conditions, but not at a field research site near Fort McMurray, Alberta. In a greenhouse study, alleviating soil moisture stress significantly increased height, RCD, and biomass of tree seedlings. Vigorous growth of ground cover vegetation stimulated by fertilizer addition in both the greenhouse and field, largely controlled survival and growth responses of tree seedlings. Survival rates of tree seedlings were significantly decreased with increased fertilizer application rates, and no positive growth responses were observed in the field. Maximum seedlings survival (92%) was recorded without fertilization. Trembling aspen was sensitive to ground cover competition, whereas white spruce was unaffected. The inherent fertility of the peat-mineral mixture appeared sufficient for establishment and early growth of planted tree seedlings in recently reclaimed oil sands sites. Fertilization appeared to increase competition between tree seedlings and cover vegetation by promoting increased growth and competition for other resources like water. Effects on growth over the longer term (several years) should be evaluated in future studies.
46
Hölldampf, Bärbel. "Assessment of mineral nutrition of declining forest trees with red spruce seedlings and indicator plants /." 1992. https://scholarworks.umass.edu/theses/3428.
Full text
47
Mohammed, Idris. "Growth and nutrition of black spruce seedlings in pot culture: Effect of nutrient loading, fertilization and interplanting." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442057&T=F.
Full text
48
Lévesque, Françoise. "Carbohydrates in white spruce and lodgepole pine seedlings during winter : outdoors, in freezer-storage and in thawing." Thesis, 1995. http://hdl.handle.net/2429/4191.
Full textAbstract:
Studies were conducted to examine factors associated with total non-structural
carbohydrate (TNC) depletion during winter, either outdoors, in freezer-storage or in
thawing. To see if TNC depletion was mainly due to respiration, two experiments were
conducted. In Experiment 1, respiratory C02 evolution of white spruce (Picea glauca
(Moench) Voss.) was monitored in -2°C storage for 4 months and in +2°C and +7°C
thawing regimes for 6 weeks. In Experiment 2, white spruce and lodgepole pine (Pinus
contorta Dougl.) respiration was monitored in -2°C storage for 2 months. In the
following 6 weeks of +2°C and +7°C thawing regimes, only spruce respiration frost hardiness in storage. Starch synthesis occurred in -2°C storage although no clear
environmental signals could have triggered this activity.
Soluble sugars were analyzed by HPLC to explore sugar dynamics in relation
to frost hardiness and growth resumption. Spruce and pine seedlings from outdoors,
the 4 months freezer-storage treatment and the +2°C thawing regime were analyzed.
Contents of individual sugars were plotted against frost hardiness to identify any
relationship to dehardening. The results suggested that shoot raffinose content is well
correlated with hardiness of spruce and pine. More species and conditions need to be
tested to establish the strength of this relationship.
To explore the possibility of root to shoot CH2O transport via phloem, white
spruce seedlings were girdled at the collar zone. Intact and girdled seedlings were
freezer-stored for 4 months and transferred to a +2°C thawing regime for 4 weeks.
Thereafter, the temperature in thawing was increased to +7°C for 2 additional weeks.
Shoot and root TNC content were compared for intact and girdled seedlings. The
results showed that significant phloem transport was not likely in -2°C storage or when
seedlings were exposed to +2°C for 4 weeks. However, once transferred to +7°C,
there was a disproportionate accumulation of free sugars in roots of girdled seedlings,
suggesting that normal root to shoot phloem transport was blocked.
monitoring was considered in Experiment 2. TNC was measured every month
beginning in December in white spruce and lodgepole pine for seedlings overwintered
outdoors for 3 months, for seedlings left outdoors 2 months and then lifted in February
for freezer-storage, and for seedlings freezer-stored for 4 months. TNC was also
measured twice during the two thawing regimes for seedlings cold-stored for 2 and 4
months. Respiration rates and TNC depletion were compared. Frost hardiness was
monitored for spruce and pine at months 0, 2 and 4 during freezer-storage and every
two weeks during thawing. For seedlings kept outdoors, frost hardiness was monitored
at months 0, 2 and 3.
Respiration increased following a disturbance (e.g. lifting for storage) but
stabilized at a lower steady-state rate thereafter. Measured TNC depletion matched
respiration rate in the 4 months freezer-storage but not in any other cases. The Q10
calculated between -2°C and +2°C was found to be extreme for steady-state
respiration rates, indicating a disproportionate increase in activity when seedlings are
transferred from freezer-storage to thawing. Frost hardiness was released relatively
slowly following 4 months of freezer-storage. Dehardening was faster for seedlings
kept outdoors. Seedlings placed in freezer-storage in February were able to regain
49
Sun, Zongjia. "Stable carbon isotopes as indicators of increased water-use efficiency and biomass production in white spruce (Picea glauca (Moench) voss) seedlings grown under different water and nitrogen regimes." Thesis, 1995. http://hdl.handle.net/1828/6572.
Full text
50
Smit, Julie. "Effects of root growth and physiology on drought resistance in Douglas-fir, lodgepole pine, and white spruce seedlings." Thesis, 1993. https://dspace.library.uvic.ca//handle/1828/9656.
Full textAbstract:
Two aspects of drought resistance were investigated on wet and dry ecotypes
of three conifer species: 1) the relative importance of drought avoidance and
drought tolerance mechanisms in resisting drought stress was assessed on Douglas-fir
(Pseudotsuga menzieseii) and lodgepole pine (Pinus contorta) seedlings, and 2)
the effects of drought on root hydraulic conductance and low temperature, on root
water flow rates Were assessed on first-year seedlings of Douglas-fir, lodgepole
pine and white spruce (Picea glauca).
To study drought avoidance, Douglas-fir and lodgepole pine seedlings were
grown in sealed containers in wet (522% water content) or dry (318% water
content) peat/vermiculite soil in a factorial treatment design. Dry weights, water
use, and root length were determined for seedlings at each of five harvests and
stomatal conductance and shoot water potentials were measured during the last 12
weeks of the experiment. Lodgepole pine seedlings had greater dry matter
production, water use, stomatal conductance and new root length than Douglas-fir
seedlings. New root weight of lodgepole pine seedlings exceeded that of Douglas-fir
seedlings during the last five weeks of the experiment, and specific root length
of new roots was higher for lodgepole pine seedlings throughout the experiment.
Douglas-fir seedlings showed higher water use efficiency (WUE) than lodgepole
pine seedlings, although water uptake rates per unit of root dry weight showed
little difference between species. Soil water treatment influenced specific root
length of new roots, water uptake per unit of new root length, and WUE in
Douglas-fir seedlings more than in lodgepole pine seedlings.
To study drought tolerance, Douglas-fir and lodgepole pine seedlings were
grown under drought and well-watered conditions. At each of three harvests a
pressure-volume curve was produced for each seedling. Douglas-fir maintained a
lower osmotic potential at full saturation [special characters omitted] and lower turgor loss point [special characters omitted] than lodgepole pine under both watering regimes,. Both species had lower
[special characters omitted] when drought-stressed.
Douglas-fir appears to be a more conservative species, maintaining low
stomatal conductance and tolerating drought conditions, whereas lodgepole pine
avoids drought by producing large amounts of roots to exploit the soil resource.
To study root hydraulic conductance (Lproot) and water flow rates through
roots (WFRR), water flow was measured through de-topped roots of Douglas-fir,
lodgepole pine, and white spruce seedlings in a pressure chamber. In a drought
experiment, seedlings were grown in sandy soil in a greenhouse under drought and
well-watered conditions during their first growing season and, in a low temperature
experiment, seedlings were grown in sandy soil in growth chambers at 25/20°C
(day/night) and 15/10°C,
In the drought experiment, water flow through roots was measured at three
pressures. No differences in Lproot were found for Douglas-fir and white spruce
seedlings grown under the two watering regimes, however, lodgepole pine
seedlings had reduced Lproot when grown under drought conditions. Welk
watered seedlings of lodgepole pine and white spruce had higher Lpr00t in 1989
than in 1990 whereas Douglas-fir seedlings had the same Lproot in both years.
In the low temperature experiment, WFRR was measured at 1.0 MPa and
temperatures of 20°C for 24 hours or 20°, 12°, and 4°C for 18, 15, and 15 hours
respectively. At 20°C, white spruce seedlings had higher WFRR than the other
two species. Lodgepole pine and white spruce seedlings grown in the 1S°/10°C
growth chamber had higher WFRR than seedlings grown in the 25°/20°C growth
chamber. Water flow rate decreased with temperature in all three species. After
correcting for viscosity, all seedlings had lower WFRR with reduced temperature,
except for Douglas-fir and white spruce seedlings grown at 15°/10°C which had
the same WFRR at 20°C and 12°C. Therefore, Douglas-fir and white spruce
seedlings were found to become less sensitive to low temperature (chilling) stress
when pre-conditioned at low temperatures.
In the drought and low temperature studies, dry weight biomass of white
spruce was lowest but white spruce had a greater specific root length than
lodgepole pine and Douglas-fir. In the drought study, biomass production in
seedlings from wet ecotypes of each species was more reduced when drought-stressed than seedlings from dry ecotypes.<br>Graduate