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Thesis (doctoral)--Vereinigten Friedrichs-Universität Halle-Wittenberg, 1914. / Cover title. Bibliography: p. 57-59.

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Natural environments are often limiting to plant growth in more than one resource due to the simultaneous fluctuations in resource supply and demand. The mechanisms a species uses to acclimate to simultaneous resource variation may not be uniform among species of the same growth form. Four evergreen ericaceous shrubs responded individualistically to fluctuations in light and water in an experimental garden study. <i>Rhododendron maximum</i> and <i>Kalmia latifolia</i> were able to acclimate photosynthetically to high and low irradiance under both high and low water availability. <i>Rhododendron catawbiense</i> and <i>R. minus</i> showed significantly higher acclimation to high light in high water treatments. All four species were able to reduce their osmotic potential and water deficit at the turgor loss point seasonally, especially in low water treatments. Low soil water availability also reduced midday conductance and water potential in all four species. Rhododendron maximum and <i>R. catawbiense</i> were very conservative in their water use patterns. <i>Rhododendron minus</i> and <i>K. latifolia</i> exercised less stomatal control over water loss but did not appear to experience water stress under these treatment conditions. Rhododendron catawbiense was the most sensitive to low water availability and had the lowest turgor pressure of the four species. Daily carbon dioxide assimilation was highest in high light, high water. treatments and lowest in low light, low water treatments for all four species. During the two years of this study, these species did not show any consistent pattern of increased growth in the high light, high water treatments where carbon dioxide assimilation was highest. Since these species are native to low resource habitats, their abilities to significantly increase growth during periods of high resource availability may be less than that of plants adapted to high resource availability. The results of these experiments indicate that these four species of the same growth form respond differently to simultaneous fluctuations in light and water resources. / Ph. D.

The principle aim of this work was to ascertain the relative importance of water and nutrient supply in determining the success of deciduous and evergreen plant forms on two main substrate types in the Worcester-Robertson valley, situated in the Succulent Karoo Biome. The substrate types selected for study represent soils of zoogenic soil mounds (locally termed "heuweltjies", and often referred to in the literature as "Mirna-like" mounds), and soils immediately adjacent to and surrounding the soil mounds. The distribution of deciduous and evergreen plant forms in the Worcester-Robertson valley was analys~d relative to the selected substrate types. Foliar elemental concentrations of four selected species growing on both substrates at five separate sites within the valley were determined. Also, the patterns of seasonal water stress exhibited by three deciduous and five evergreen non-succulent woody perennials growing in both substrates were investigated on high radiation (equator-facing) and low radiation (pole-facing) slopes at one intensive study site, the Worcester Veld Reserve.

Call number: LD2668 .T4 1979 C5266 / Master of Science

Call number: LD2668 .T4 1979 F85 / Master of Science

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Includes bibliographical references.

Kong Hoi-Yeung. / Thesis submitted in: November 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 132-146). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.v / Table of contents --- p.vii / List of tables --- p.x / List of figures --- p.xi / List of plates --- p.xii / List of appendices --- p.xii / Chapter Chapter one --- Introduction / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Afforestation in Hong Kong --- p.2 / Chapter 1.3 --- Conceptual framework of the study --- p.6 / Chapter 1.4 --- Objectives of the study --- p.13 / Chapter 1.5 --- Scope and significance of the study --- p.14 / Chapter 1.6 --- Organization of the thesis --- p.15 / Chapter Chapter Two --- The Study Area / Chapter 2.1 --- Geographical setting of Hong Kong --- p.17 / Chapter 2.1.1 --- Climate --- p.17 / Chapter 2.1.2 --- Geology --- p.19 / Chapter 2.1.3 --- Soils --- p.20 / Chapter 2.1.4 --- Vegetation --- p.21 / Chapter 2.1.5 --- Characteristics of Lophostemon confertus --- p.23 / Chapter 2.2 --- Site selection --- p.24 / Chapter Chapter Three --- Stand Characteristics of Lophostemon confertus Plantations / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Methodology --- p.35 / Chapter 3.2.1 --- Sample plots design --- p.35 / Chapter 3.2.2 --- Tree density --- p.35 / Chapter 3.2.3 --- Tree growth parameters --- p.35 / Chapter 3.2.4 --- Data processing and statistical analysis --- p.36 / Chapter 3.3 --- Results and discussion --- p.37 / Chapter 3.3.1 --- Tree density and mortality rate --- p.37 / Chapter 3.3.2 --- Growth performance of Lophostemon confertus --- p.39 / Chapter 3.3.3 --- Growth rate of Lophostemon confertus in the plantations --- p.41 / Chapter 3.4 --- Conclusion --- p.44 / Chapter Chapter Four --- Soil Characteristics of Lophostemon confertus Plantations / Chapter 4.1 --- Introduction --- p.47 / Chapter 4.2 --- Methodology --- p.51 / Chapter 4.2.1 --- Soil sampling --- p.51 / Chapter 4.2.2 --- Laboratory analysis --- p.52 / Chapter 4.2.3 --- Texture --- p.52 / Chapter 4.2.4 --- Soil pH --- p.53 / Chapter 4.2.5 --- Organic carbon --- p.53 / Chapter 4.2.6 --- Total Kjeldahl Nitrogen (TKN) --- p.53 / Chapter 4.2.7 --- Carbon: Nitrogen ratio --- p.54 / Chapter 4.2.8 --- Mineral nitrogen (NH4-H and N03-N) --- p.54 / Chapter 4.2.9 --- Available phosphorus --- p.55 / Chapter 4.2.10 --- Exchangeable cations --- p.55 / Chapter 4.3 --- Data processing and statistical analysis --- p.55 / Chapter 4.4 --- Results and discussion --- p.56 / Chapter 4.4.1 --- Soil texture --- p.56 / Chapter 4.4.2 --- Effects of Lophostemon confertus plantations on reaction pH --- p.58 / Chapter 4.4.3 --- "Effects of Lophostemon confertus plantations on SOM, TKN and mineral nitrogen" --- p.59 / Chapter 4.4.4 --- Effects of Lophostemon confertus plantations on available P and exchangeable cations --- p.69 / Chapter 4.4.5 --- Effects of Lophostemon confertus plantations on nutrient status of the soils --- p.73 / Chapter 4.5 --- Conclusion --- p.79 / Chapter Chapter Five --- Understorey Vegetation of Lophostemon confertus Plantations / Chapter 5.1 --- Introduction --- p.81 / Chapter 5.2 --- Methodology --- p.85 / Chapter 5.2.1 --- Understorey plant sampling --- p.85 / Chapter 5.2.2 --- Species identification and nomenclature --- p.86 / Chapter 5.2.3 --- Plant growth parameters --- p.87 / Chapter 5.2.4 --- Data processing and statistical analysis --- p.87 / Chapter 5.3 --- Results and discussion --- p.89 / Chapter 5.3.1 --- Floristic composition of the Lophostemon confertus plantations --- p.89 / Chapter 5.3.2 --- "Species richness, diversity and woody abundance of the understorey" --- p.93 / Chapter 5.3.3 --- Species composition and structure of understories --- p.99 / Chapter 5.3.4 --- Dynamics of species establishment in the understorey --- p.109 / Chapter 5.4 --- Conclusion --- p.112 / Chapter Chapter Six --- Conclusion / Chapter 6.1 --- Summary of findings --- p.114 / Chapter 6.2 --- Implications of the study --- p.118 / Chapter 6.2.1 --- Ecological value of Lophostemon confertus plantations in Hong Kong --- p.118 / Chapter 6.2.2 --- Rehabilitation of badland derived from granite --- p.124 / Chapter 6.2.3 --- Management of the existing plantations --- p.126 / Chapter 6.3 --- Limitations of the study --- p.129 / Chapter 6.4 --- Suggestions for future study --- p.130 / References --- p.132 / Appendices --- p.147

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