Thesis (M.S.)--Oregon State College, 1956. / Typescript. Includes bibliographical references (leaves 74-75). Also available on the World Wide Web.

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Thesis (M.S.)--Oregon State College, 1953. / Typescript. Includes bibliographical references (leaves 55-59). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 1993. / Typescript (photocopy). Includes bibliographical references (leaves 169-175). Also available on the World Wide Web.

Bibliography: pages 171-181. / Studies of forest ecosystems have indicated that internal sources constitute a significant component of the acid load to forest soils and can result in significant decreases in soil pH, acid neutralising capacity and base status. Despite this, the possibility that these processes can result in a significant transfer of acidity to drainage solutions and consequently to associated surface waters has, to a large extent, been discounted due to the self-limiting nature of " natural" acidification processes which purportedly do not involve significant concentrations of the strong acid anions NO₃⁻, SO₄²⁻ and Cl⁻. In South Africa, extensive plantations of Pinus spp. (pine) are developed in mountainous regions that were previously covered by grassland or fynbos (macchia) vegetation and are mostly not believed to be influenced by significant atmospheric pollution. Thus, a good opportunity exists to study the effects of afforestation without the superimposed influence of acid deposition. This thesis documents the results of a regional investigation of the geochemical impact of pine afforestation in South Africa. The study focuses specifically on factors relating to the transfer of soil acidity to drainage waters. The key questions that are addressed are : 1) to what extent is soil acidification, as previously documented for plantations in the eastern seaboard region of southern Africa, prevalent in other forestry areas within South Africa?; 2) in the absence of acid deposition, can afforestation cause enhanced concentrations of strong acid anions in soil solutions and drainage waters, and can this lead to the transfer of large quantities of acidity from forest soils to surface waters ?; 3) does afforestation-induced acidification lead to increased concentrations of environmentally important metals such as Al and Mn in soil solutions and surface waters ?; and 4) how does afforestation affect the quantity of dissolved organic matter in soils and streams?

Since 1982, the state of Illinois has afforested over 100,000 acres of abandoned or marginal cropland. Afforestation, the planting of trees on land not in forest cover, is a sustainable forest management practice that has been shown to store carbon, increase plant diversity, improve soil and water quality, and assist in flood abatement. Our research seeks to develop practical soil and vegetative indicators that can be used by researchers and land managers alike to accurately assess changes to ecosystem function following land use shifts. To assess forest restoration success in terms of ecological function, seven ecological indicators were measured across a chronosequence of 50 afforested sites and 20 mature forested sites. Soil indicators: bulk density, aggregate stability, total nitrogen, total carbon, and labile carbon, and vegetation indicators: forest productivity and stocking density were assessed for each site. Additional sampling was completed on 25 nearby agriculture fields for each of the five soil indicators. Our data were analyzed using an analysis of variance test with multiple comparisons to examine differences among indicator values by land use category. Overall, soil indicator bulk density significantly decreased across afforested sites with stand age, whereas indicators aggregate stability, labile carbon, and total carbon significantly increased across afforested sites with stand age. Linear regression analyses were used to assess the change in indicator values with stand age. Additional linear regression analyses were used to assess the change in indicator values with site index, and significant results were recorded for 3 out of the 5 soil indicators. Indicator bulk density displayed a significant negative relationship with site index, and indicators aggregate stability and total carbon displayed a significant positive relationship with site index. Overall, our results indicated that four out of the five soil parameters measured were successful indicators of restored ecological function in afforested sites. Furthermore, we believe that the inclusion of vegetation indices forest productivity and stocking density provides vital information into forest succession and a better understanding of how productive sites benefit soil quality.

The objective of this study was to examine some mechanisms of bottomland hardwood afforestation and their impacts on above- and belowground carbon sequestration. Six combinations of bottomland hardwood species and two levels each of fertilizer and herbicide were applied in a completely randomized design on two sites in the LMAV. Survival, ground line diameter and total height were monitored for two growing seasons. Soil carbon and nitrogen to a depth of one meter, herbaceous biomass, and tree biomass were sampled in the first and second years of establishment. Species mixes, fertilizer, and herbicide application significantly affected survival, growth, above- and belowground tree biomass carbon after two years of establishment. Survival was generally average, while growth for most species mixes was below expectation. Species mixes E (green ash/oak mix) and F (NRCS species mix) had the highest tree vegetation carbon both above- and belowground. Soil carbon and nitrogen were not significantly affected by any treatments.

published_or_final_version / Geography and Geology / Master / Master of Philosophy

Chan, Fong Fiona. / Thesis submitted in: October 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 165-178). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.v / Table of Contents --- p.vi / List of Tables --- p.ix / List of Figures --- p.x / List of Plates --- p.xi / List of Appendices --- p.xii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- The problems --- p.3 / Chapter 1.3 --- Conceptual framework --- p.10 / Chapter 1.4 --- Objectives of the study --- p.13 / Chapter 1.5 --- Significance --- p.14 / Chapter 1.6 --- Organization of the thesis --- p.15 / Chapter CHAPTER 2 --- LITERATURE REVIEW / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- Ecological rehabilitation --- p.19 / Chapter 2.3 --- Definition of exotic and native species --- p.20 / Chapter 2.4 --- Forest degradation --- p.21 / Chapter 2.4.1 --- Present situation of tropical forests --- p.21 / Chapter 2.4.2 --- Plantation history in Hong Kong --- p.22 / Chapter 2.5 --- Disturbances and rehabilitation strategies --- p.24 / Chapter 2.6 --- The role of plantation --- p.25 / Chapter 2.7 --- Exotic tree species versus native tree species --- p.28 / Chapter CHAPTER 3 --- THE STUDY AREA / Chapter 3.1 --- Location --- p.33 / Chapter 3.2 --- Climate --- p.35 / Chapter 3.3 --- Geology --- p.37 / Chapter 3.4 --- Soils --- p.38 / Chapter 3.5 --- Vegetation --- p.38 / Chapter 3.6 --- Planting designs and management --- p.42 / Chapter CHAPTER 4 --- SOIL CHARACTERISTICS AND PROPERTIES / Chapter 4.1 --- Introduction --- p.44 / Chapter 4.2 --- Methodology --- p.47 / Chapter 4.2.1 --- Sampling --- p.47 / Chapter 4.2.2 --- Soil texture --- p.49 / Chapter 4.2.3 --- Bulk density and porosity --- p.49 / Chapter 4.2.4 --- Penetration resistance --- p.50 / Chapter 4.2.5 --- Soil reaction and conductivity --- p.50 / Chapter 4.2.6 --- Organic carbon --- p.50 / Chapter 4.2.7 --- Total Kjeldahl nitrogen (TKN) --- p.51 / Chapter 4.2.8 --- Mineral nitrogen (ammonium and nitrate nitrogen) --- p.51 / Chapter 4.2.9 --- Total phosphorus --- p.51 / Chapter 4.2.10 --- Available phosphorus --- p.52 / Chapter 4.2.11 --- Exchangeable cations --- p.52 / Chapter 4.2.12 --- Exchangeable A1 and H --- p.52 / Chapter 4.3 --- Data processing and statistical analysis --- p.53 / Chapter 4.4 --- Results and discussion --- p.53 / Chapter 4.4.1 --- Physical properties --- p.54 / Chapter 4.4.2 --- Conductivity --- p.57 / Chapter 4.4.3 --- Soil reaction and exchangeable acidity --- p.57 / Chapter 4.4.4 --- Organic matter --- p.61 / Chapter 4.4.5 --- Total Kjeldahl nitrogen and mineral nitrogen --- p.63 / Chapter 4.4.6 --- C:N ratio --- p.65 / Chapter 4.4.7 --- Total and available phosphorus --- p.65 / Chapter 4.4.8 --- Nutrient cations --- p.67 / Chapter 4.4.9 --- Comparison with other disturbed sites --- p.69 / Chapter 4.5 --- Conclusion --- p.72 / Chapter CHAPTER 5 --- SURVIVAL AND GROWTH PERFORMANCE / Chapter 5.1 --- Introduction --- p.75 / Chapter 5.2 --- Methodology --- p.83 / Chapter 5.2.1 --- Sampling --- p.83 / Chapter 5.2.2 --- Data processing and statistical analysis --- p.85 / Chapter 5.3 --- Results and discussion --- p.85 / Chapter 5.3.1 --- Survival rate --- p.85 / Chapter 5.3.2 --- Growth performance between trial plots --- p.96 / Chapter 5.3.3 --- Growth performance among species --- p.100 / Chapter 5.3.4 --- Plantation management and species selection --- p.109 / Chapter 5.4 --- Conclusion --- p.113 / Chapter CHAPTER 6 --- FOLIAR COMPOSITION OF SPECIES / Chapter 6.1 --- Introduction --- p.116 / Chapter 6.2 --- Methodology --- p.121 / Chapter 6.2.1 --- Foliage sampling --- p.121 / Chapter 6.2.2 --- Chemical analysis --- p.123 / Chapter 6.2.2.1 --- Total Kjeldahl nitrogen (TKN) --- p.123 / Chapter 6.2.2.2 --- Total phosphorus and cation nutrients --- p.123 / Chapter 6.2.3 --- Data processing and statistical analysis --- p.124 / Chapter 6.3 --- Results and discussion --- p.124 / Chapter 6.3.1 --- Foliage composition of existing vegetation --- p.124 / Chapter 6.3.2 --- Foliage composition of planted species --- p.131 / Chapter 6.4 --- Conclusion --- p.143 / Chapter CHAPTER 7 --- CONCLUSION / Chapter 7.1 --- Summary of findings --- p.146 / Chapter 7.2 --- Implications of the study --- p.151 / Chapter 7.2.1 --- Silviculture involving native species --- p.151 / Chapter 7.2.2 --- Screening of species --- p.154 / Chapter 7.2.3 --- Native forest succession --- p.156 / Chapter 7.2.4 --- Potentials of native legumes --- p.158 / Chapter 7.3 --- Limitation of the study --- p.159 / Chapter 7.4 --- Suggestions for future study --- p.161 / REFERENCES --- p.165 / APPENDICES --- p.179

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Thesis documentation sheet inserted. Appendix reprints five journal articles and manuscripts co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.