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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

Écologie des érablières à sucre (Acer saccharum Marsh.) à leur limite nord de distribution au Saguenay-Lac-Saint-Jean /

Bilodeau, Janie, January 1992 (has links)
Mémoire (M.Ress.Renouv.)-- Université du Québec à Chicoutimi, 1992. / Résumé disponible sur Internet. CaQCU Bibliogr.: f. 73-76. Document électronique également accessible en format PDF. CaQCU
42

Le système racinaire de quelques érabliéres du Québec /

Lajeunesse, Denyse January 1990 (has links)
No description available.
43

Post-Transplant Root Production, Mortality, and Periodicity of Landscape-Sized Shade Trees

Richardson-Calfee, Lisa E. 06 August 2003 (has links)
A more thorough knowledge of rooting behavior of transplanted trees is needed to better understand plant establishment. The objectives of this research were to: 1) determine if transplant timing affected root system regeneration of northern red oak (Quercus rubra L.) and willow oak (Q. phellos L.), 2) determine the effect of transplant timing and nursery production system on root, shoot, and trunk growth periodicity of balled-and-burlapped (B&B) and pot-in-pot (PIP) sugar maple (Acer saccharum Marsh.), and 3) characterize seasonal patterns of root production and mortality of transplanted sugar maple. No new root growth occurred outside or within the root balls of red or willow oak between November transplanting and January excavation. However, new root growth was observed when November- and March-transplanted oaks were excavated in April, indicating that new root growth occurs primarily in late winter and/or early. Transplanted and non-transplanted sugar maples exhibited a pattern of maximum rates of shoot extension in early May, root length accumulation in late May, and trunk expansion in mid June. Rate of root length accumulation was less in summer and fall. Transplanting did not appear to disrupt the normal growth periodicity of sugar maple, except when transplanted in July. Abundant root length accumulation occurred in the July transplants at a time when root length accumulation had slowed in all other treatments, resulting in the July transplants having similar standing root lengths as the other transplants by fall. Standing root length of non-transplanted PIP sugar maple declined dramatically in spring. While root production in sugar maple was limited to the growing season, root mortality occurred at a steadier rate throughout the year. Most root mortality occurred in winter in transplanted trees and spring and summer in non-transplanted trees. Non-transplanted PIP trees had greater standing root length, production, and mortality than the other treatments. Indices of root activity (analogous to turnover rates) and production:mortality ratios illustrated the dominant role that root production plays relative to mortality in recently transplanted trees. These data indicate that transplanting and the PIP production system disrupt typical patterns of root production and mortality in sugar maple. / Ph. D.
44

Water Use of Landscape Trees During Pot-In-Pot Production and During Establishment in the Landscape

Witmer, Robert K. 03 January 2001 (has links)
Water conservation and pollution concerns from nutrient runoff will very likely dictate precise irrigation regimes for nursery managers in Virginia. Maximum plant growth with minimum input of water and fertilizer is becoming increasingly important. Therefore, water use and growth of red and sugar maple (Acer rubrum L. 'Franksred' and Acer saccharum Marsh.) were studied during two years of pot-in-pot (P+P) production and during three years after transplanting to field soil. Three major experiments were completed. The first experiment studied the effect of frequent irrigation (three-times-a-day) versus standard once-a-day irrigation and found that frequent irrigation increased trunk diameter growth of sugar maples in the second production cycle and for red maples in both production cycles. Height growth of neither species was affected by frequent irrigation. A study of sap flow pattern indicated that late day water stress of red maples was partially alleviated by frequent irrigation. In the second experiment, red and sugar maples were transplanted to field soil after one (1-yr) or two (2-yr) years of P+P production. Irrigation frequency requirement decreased as the trees grew and depended on environmental conditions, size at planting, source of water (rainfall versus irrigation) and species. Height and trunk diameter of 1-yr red maple was equal to that of 2-yr trees after only one year. Height and trunk diameter differences between 1-yr and 2-yr sugar maple trees persisted three years after transplanting. In the third experiment water use of 1-yr and 2-yr red and sugar maple while in P+P production was investigated. Four models of daily water-use were developed. A simple model that is suitable for growers includes species, trunk cross-sectional area (BA) and air temperature (TA) observations. An environmental model was developed using the Penman-van Bavel estimate of evapotranspiration (ET). ET required modifications based on tree characteristics, air temperature, windspeed and relative humidity to be an effective predictor of water-use. A complex model was based on a sine-cosine function of day-of-the-year. This model fits water-use data well for each species and production cycle and includes BA, ET and TA. An alternate simpler model requires only day-of-the-year, TA and BA, offering growers a relatively simple and accurate model of water use. / Ph. D.
45

The Effects of Chronically Elevated N and S Deposition on the Nutrition and Physiology of Sugar Maple at the Bear Brook Watershed in Maine

Bethers, Suzanne January 2008 (has links) (PDF)
No description available.
46

Tree-age distributions in a northern hardwood forest

Cook, Bryan January 1971 (has links)
No description available.
47

Tree-age distributions in a northern hardwood forest

Cook, Bryan January 1971 (has links)
No description available.
48

Fertilization effects on soil and foliar nutrient status in relation to declining sugar maple (Acer saccharum Marsh.)

Spankie, Heather A. (Heather Anne) January 1990 (has links)
Eight fertilization treatments were applied in May 1987 to two sugar maple stands. This was followed by soil and foliar sampling and decline evaluation in mid-summer 1987 and foliar sampling and decline evaluation in mid-summer 1988. / Trees selected for sampling purposes on average showed evidence of light to moderate decline. Foliar nutrient status was found to be poor at both sites, with Ca, Mg, K and P at or very near to deficiency levels although foliar molar ratios for Ca/K, Ca/Mg and Ca/Al were well within their respective critical ranges. / Fertilization had significant effects on several elemental concentrations of the soil and foliage at the Entrelacs sites. Effects in general showed an increase in base cation concentrations when those elements were supplied in high enough quantities in the fertilizers. Fertilization had no significant effect on decline levels. / Positive correlations were obtained between soil B horizon levels and foliar Ca, Mg and K and between soil FH horizon levels and foliar K and Al.
49

Tree transpiration varies spatially in response to atmospheric and edaphic conditions

Traver, Elizabeth. January 2007 (has links)
Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Nov. 26, 2008). Includes bibliographical references (p. 24-33).
50

Root-to-shoot communication in response to drought : a comparison of four central hardwood tree species /

Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.

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