Chan, Hoi Weun Kilkenny. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 233-248). / Abstract also in Chinese. / ABSTRACT --- p.i / ABSTRACT (IN CHINESE) --- p.iv / ACKNOWLEDGEMENTS --- p.vi / TABLE OF CONTENTS --- p.viii / LIST OF TABLES --- p.xii / LIST OF FIGURES --- p.xiv / LIST OF PLATES --- p.xvi / LIST OF APPENDICES --- p.xvii / LIST OF ABBREVIATIONS --- p.xviii / Chapter CHAPTER ONE --- INTRODUCTION / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Conceptual framework --- p.4 / Chapter 1.3 --- Study objectives --- p.9 / Chapter 1.4 --- Significance of research --- p.10 / Chapter 1.5 --- Organization of thesis --- p.12 / Chapter CHAPTER TWO --- LITERATURE REVIEW / Chapter 2.1 --- Introduction --- p.14 / Chapter 2.2 --- The geographical setting of Hong Kong --- p.14 / Chapter 2.2.1 --- Climate of Hong Kong --- p.14 / Chapter 2.2.2 --- Geology of Hong Kong --- p.16 / Chapter 2.2.3 --- Soils of Hong Kong --- p.17 / Chapter 2.2.4 --- Vegetation of Hong Kong --- p.18 / Chapter 2.3 --- Forestry management in Hong Kong --- p.19 / Chapter 2.4 --- Land degradation and growth constraints --- p.20 / Chapter 2.5 --- Importance of ecological rehabilitation --- p.23 / Chapter 2.6 --- Use of exotic and native species in ecological rehabilitation --- p.27 / Chapter 2.7 --- Myths of native species --- p.32 / Chapter 2.8 --- Quarrying and quarry rehabilitation in Hong Kong --- p.34 / Chapter 2.8.1 --- Permit quarries --- p.34 / Chapter 2.8.2 --- Contract quarries --- p.36 / Chapter 2.8.3 --- Quarry rehabilitation contracts --- p.37 / Chapter 2.9 --- Constraints of quarry rehabilitation --- p.39 / Chapter 2.10 --- Characteristics of quarry growth substrates --- p.41 / Chapter 2.11 --- Soil amendment materials --- p.42 / Chapter 2.12 --- Summary --- p.43 / Chapter CHAPTER THREE --- SCREENING OF SOIL AMENDMENT MATERIALS FOR THE GROWTH OF SCHIMA SUPERB A / Chapter 3.1 --- Introduction --- p.44 / Chapter 3.2 --- Methodology --- p.46 / Chapter 3.2.1 --- Experimental design --- p.46 / Chapter 3.2.2 --- Post-planting care --- p.53 / Chapter 3.2.3 --- Plant performance measurements --- p.53 / Chapter 3.3 --- Laboratory analysis --- p.55 / Chapter 3.3.1 --- Soils --- p.55 / Chapter 3.3.2 --- Amendment materials --- p.59 / Chapter 3.3.3 --- Foliar nutrient contents --- p.60 / Chapter 3.4 --- Statistical analysis --- p.61 / Chapter 3.5 --- Results and discussion --- p.61 / Chapter 3.5.1 --- Physical and chemical properties of decomposed granite --- p.61 / Chapter 3.5.2 --- Chemical properties of soil amendment materials --- p.64 / Chapter 3.5.3 --- Plant growth performance --- p.68 / Chapter 3.5.4 --- Effect of SAMs on growth performance of the seedlings --- p.78 / Chapter 3.6 --- Summary --- p.81 / Chapter CHAPTER FOUR --- SOILS AND VEGETATION CHARACTERISTICS OF THREE RESTORED QUARRY SITES / Chapter 4.1 --- Introduction --- p.85 / Chapter 4.2 --- Study area --- p.87 / Chapter 4.3 --- Methodology --- p.92 / Chapter 4.3.1 --- Experimental design --- p.92 / Chapter 4.3.2 --- Soil sampling --- p.93 / Chapter 4.3.3 --- Vegetation survey --- p.94 / Chapter 4.4 --- Data processing and statistical analysis --- p.95 / Chapter 4.5 --- Results and discussion --- p.96 / Chapter 4.5.1 --- Characteristics and properties of the restored soils --- p.96 / Chapter 4.5.2 --- Vegetation survey --- p.110 / Chapter 4.6 --- Summary --- p.130 / Chapter CHAPTER FIVE --- EFFECT OF ENGINEERING DESIGN AND RAINSTORM ON ECOLOGICAL REHABILITATION / Chapter 5.1 --- Introduction --- p.133 / Chapter 5.2 --- Methodology --- p.135 / Chapter 5.2.1 --- Experimental design --- p.135 / Chapter 5.2.2 --- Assessment of plant growth and storm damage --- p.142 / Chapter 5.2.3 --- Laboratory analysis --- p.143 / Chapter 5.3 --- Statistical analysis --- p.143 / Chapter 5.4 --- Results and discussion --- p.143 / Chapter 5.4.1 --- Physical and chemical properties of the growth substrate --- p.143 / Chapter 5.4.2 --- Chemical properties of the soil amendment materials --- p.146 / Chapter 5.4.3 --- The weather and growth conditions in ARQ --- p.149 / Chapter 5.4.4 --- Damage caused by the rainstorm --- p.155 / Chapter 5.4.5 --- Survival rates of the seedlings --- p.161 / Chapter 5.4.6 --- Growth performance of seedlings 3 months after planting --- p.163 / Chapter 5.4.7 --- Lessons learnt from this experiment --- p.167 / Chapter 5.5 --- Summary --- p.174 / Chapter CHAPTER SIX --- GROWTH OF SCHIMA SUPERBA AND RHAPHIOLEPIS INDICA ON DECOMPOSED GRANITE (DG) AND DECOMPOSED VOLCANIC (DV) / Chapter 6.1 --- Introduction --- p.177 / Chapter 6.2 --- Materials and methods --- p.179 / Chapter 6.2.1 --- Experimental design --- p.179 / Chapter 6.2.2 --- Plant performance measurements and data processing --- p.181 / Chapter 6.2.3 --- Laboratory analysis --- p.182 / Chapter 6.3 --- Statistical analysis --- p.182 / Chapter 6.4 --- Results and discussion --- p.183 / Chapter 6.4.1 --- Properties of decomposed granite and decomposed volcanic --- p.183 / Chapter 6.4.2 --- Properties of the soil amendment materials --- p.186 / Chapter 6.4.3 --- Survival rates of the seedlings --- p.188 / Chapter 6.4.4 --- Height growth of seedlings --- p.198 / Chapter 6.4.5 --- Stem basal diameter growth of seedlings --- p.201 / Chapter 6.4.6 --- Overall growth performance of seedlings --- p.203 / Chapter 6.5 --- Summary --- p.204 / Chapter CHAPTER SEVEN --- CONCLUSIONS / Chapter 7.1 --- Introduction --- p.207 / Chapter 7.2 --- Summary of major findings --- p.207 / Chapter 7.3 --- Implications of the study --- p.216 / Chapter 7.3.1 --- Screening of soil amendment materials to promote early growth of seedlings in decomposed granite --- p.216 / Chapter 7.3.2 --- Successional development in the restored quarry sites under existing revegetation programme --- p.218 / Chapter 7.3.3 --- Constraints of quarry rehabilitation --- p.221 / Chapter 7.3.4 --- Potential use of native species in quarry rehabilitation --- p.225 / Chapter 7.4 --- Limitations of the study --- p.228 / Chapter 7.5 --- Suggestions for further study --- p.230 / REFERENCES --- p.233 / APPENDICES --- p.249

Thesis (Ph.D.)--University of Western Australia, 2005.

Oyster reefs are biodiverse communities that provide many ecological and commercial benefits. However, oyster reefs have declined around the world from human activities. Oyster reef restoration programs have begun to limit some of the decline, but the need for determining the success of a program has been problematic. Passive acoustic techniques can use naturally occurring sounds produced by organisms to assess biodiversity. Passive acoustics was utilized to compare the sounds in natural and restored oyster reefs, with special attention on snapping shrimp (Alpheus spp.) snap sounds, in the St. Lucie Estuary, Florida over a one year period. Season, estuary region, habitat and day period had an effect on sound production. Passive acoustic monitoring of snapping shrimp sound production may be a useful non-destructive technique for monitoring the progress of oyster reef restoration projects once further correlations are established between environmental effects and sound production. / by Hilde P. Zenil Becerra. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

香港的山火主要是由於氣候及人類活動所引發，嚴重威脅著一些陸地上生物多樣性豐富的生境（如灌木林和林地）。在華南地區，有關火燒地的動物群落恢復生態學硏究的資料非常少，所以本硏究旨在調查山火後動物群落的復原，以及比較天然復原的林區及人工植林的生境恢復之差異。此外，枯枝落葉、物理因素及山火後的微生物對動物群落的影響亦會在此硏究中詳细分析。 / 在亞熱帶地區，地棲無脊椎動物群落的復原速度相對為慢，例如螞蟻群落需要12年的時間才能復原，但人工種植於火燒地能成功地加快其復原速度。 / 無脊椎動物群落與植被結構、山火之後的時間及生境發展都有一定的關係。山火發生兩年後火燒地的鳥類和無脊椎動物的數量、種或科的豐富度、單一性、多樣性及所有無脊椎動物的生物量都比參考樣地低，這意味著山火對動物群落有著長遠的影響。Pheidole spp. 及Tapinoma sp. 1 屬的螞蟻、隠翅甲科及小蠹科的甲蟲、管巢蛛科及狼蛛科的蜘蛛，牠們的數量，以及數量與生物量之比 (ABC plot) 都能用作反映火燒地的生態復原及演替進度的指標。 / 人工種植能夠使生態系統得到長遠的持續建立，對於動物群落的恢復非常重要。是次研究結果顯示人工種植能促進本地無脊椎動物的建群，其數量和群落亦會隨時間增加而增加。這很可能是由於山火後人工種植能為無脊椎動物創造較好的生存條件。其中，相對於原生樹種，外來樹種更有利於無脊椎動物的建群。在外來品種的人工種植區，微生物的數量較低，枯枝落葉的被分解速度較慢，加上生長速度快的外來品種能製造大量的枯枝落葉，這些都顯著增加了枯葉層的深度。較深的枯葉層為無脊椎動物提供了適宜的微生境，有利於其建群。 / 總的來說，在火燒地進行人工植樹能加快動物在火燒地的復原速度，這種方法是有效且成功的。人工種植時採用適當的品種能夠促進及預測早期的植被演替。根據此次硏究結果，我們建議在火燒地上種植生長快速的外來樹種，以加快無脊椎動物的建群。植被蓋度對動物的建群很重要，但植物和結構的多樣性及枯枝落葉層對無脊椎動物的建群更為重要。 / Hill fire in Hong Kong is mainly caused by a combination of weather and human activities. Fire is a major threat to terrestrial animal communities especially in shrublands and woodlands which have a rich faunal diversity. Since research done on hill fire ecology in southern China, especially on faunal colonization after fire, is very scarce, this research attempted to investigate the recovery of fauna after fire disturbance, and the difference in recovery between natural regeneration and artificial planting. Besides, the effects of litter and physical parameters on fauna community as well as the effect of fire on soil microbial community structure were studied. / The recolonization of ground-dwelling invertebrates was relatively slow in the study area, while proactive planting has been successful because they have considerably accelerated the return of fauna at the fire-affected sites. Ground-dwelling invertebrate communities appeared to be less resilient to fire in subtropical environment; the ant composition in the experimental plots needed 12 years to recover. / The composition of the ground-dwelling communities differed among study sites and was correlated with vegetation structure and time since last fire. They showed the trends in the development of invertebrate community composition in association with habitat development. Abundance, species/family richness, evenness, diversity of birds and ground-dwelling invertebrates, and biomass of total invertebrates were lower on the burned site than the reference site even 2 years after fire, implying that fire had longer-term impacts on the faunal communities. Ants such as Pheidole spp., Tapinoma sp. 1, beetles such as Staphylinidae, Scolytidae, and spiders such as Clubionidae, Lycosidae, as well as the abundance biomass comparison (ABC plot) can be chosen to reflect the situation or the recovery process and succession of the fire-affected sites. / The establishment of fauna in proactive planting is vital if ecosystem functions are to be reestablished and restorations to be sustained in the long term. In general the invertebrate data suggest that restoration plantings facilitated the reestablishment of indigenous invertebrate species and invertebrate community changed with time. Proactive plantings created better conditions for ground-dwelling invertebrates after fire, and exotic species with faster growth rate seem to be better than the natives. In exotic plantations, lower decomposition rate of litter provided by the lower microbial population together with higher productivity of exotic species of plants caused a higher litter depth, which provided more microhabitats for ground-dwelling and litter-dwelling invertebrates than the native plantations. / Correct species selection in proactive planting is essential to facilitate and determine the early stages of plant succession. The present study suggests that initial floristic composition is significant in proactive plantings and exotic species with fast growth rate is an effective planting species for invertebrate recolonization. Although plant cover is of importance to developing fauna, the provision of adequate floristic and structural diversity and the presence of logs and litter are important for the full range of native invertebrate recolonization. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Cheung, Kwok Leung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 192-219). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; some appendixes also in Chinese. / Abstract --- p.i / Acknowledgements --- p.vi / Table of contents --- p.vii / List of figures --- p.x / List of plates --- p.xvi / List of appendices --- p.xvii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Ecology of Fire --- p.1 / Chapter 1.2 --- Effects of Hill Fire on Soil --- p.3 / Chapter 1.3 --- Effects of Hill Fire on Microbial Communities --- p.7 / Chapter 1.4 --- Effects of Hill Fire on Vegetation --- p.10 / Chapter 1.5 --- Effects of Hill Fire on Fauna Communities --- p.14 / Chapter 1.6 --- The Use of Bioindicators on Restoration Ecology --- p.19 / Chapter 1.7 --- Hill Fire Situation and Research in Hong Kong --- p.23 / Chapter 1.8 --- Study Objectives --- p.28 / Chapter Chapter 2 --- Faunal Colonization after Fire Disturbance --- p.30 / Chapter 2.1 --- Introduction --- p.30 / Chapter 2.2 --- Materials and Methods --- p.32 / Chapter 2.2.1 --- Study sites --- p.32 / Chapter 2.2.2 --- Measurements of soil physicochemical parameters --- p.35 / Chapter 2.2.3 --- Determination of vegetation parameters --- p.36 / Chapter 2.2.4 --- Monitoring of vertebrate communities --- p.36 / Chapter 2.2.5 --- Sampling, sorting and identification of invertebrates --- p.37 / Chapter 2.2.6 --- Data analysis --- p.38 / Chapter 2.3 --- Results --- p.41 / Chapter 2.3.1 --- Soil physicochemical characteristics --- p.41 / Chapter 2.3.2 --- Vegetation parameters --- p.42 / Chapter 2.3.3 --- Vertebrate communities --- p.44 / Chapter 2.3.4 --- Invertebrate communities --- p.47 / Chapter 2.4 --- Discussion --- p.58 / Chapter 2.5 --- Conclusions --- p.66 / Chapter Chapter 3 --- Effect of Different Planting Approaches on Invertebrates --- p.68 / Chapter 3.1 --- Introduction --- p.68 / Chapter 3.2 --- Materials and Methods --- p.70 / Chapter 3.2.1 --- Study sites --- p.70 / Chapter 3.2.2 --- Proactive planting --- p.71 / Chapter 3.2.3 --- Measurement of soil, vegetation, and faunal parameters, and data analysis --- p.73 / Chapter 3.3 --- Results --- p.75 / Chapter 3.3.1 --- Soil physicochemical parameters --- p.75 / Chapter 3.3.2 --- Vegetation parameters --- p.77 / Chapter 3.3.3 --- Invertebrate communities --- p.78 / Chapter 3.4 --- Discussion --- p.92 / Chapter 3.5 --- Conclusions --- p.98 / Chapter Chapter 4 --- Long-term Changes of Invertebrate Community after Hill Fire by a Retrospective Approach --- p.100 / Chapter 4.1 --- Introduction --- p.100 / Chapter 4.2 --- Materials and Methods --- p.102 / Chapter 4.2.1 --- Study sites --- p.102 / Chapter 4.2.2 --- Measurement of soil physicochemical parameters --- p.102 / Chapter 4.2.3 --- Determination of vegetation parameters --- p.103 / Chapter 4.2.4 --- Collection, sorting and identification of invertebrates --- p.104 / Chapter 4.2.5 --- Data analysis --- p.104 / Chapter 4.3 --- Results --- p.105 / Chapter 4.3.1 --- Soil physicochemical characteristics --- p.105 / Chapter 4.3.2 --- Vegetation parameters --- p.106 / Chapter 4.3.3 --- Invertebrate communities --- p.110 / Chapter 4.4 --- Discussion --- p.123 / Chapter 4.5 --- Conclusions --- p.133 / Chapter Chapter 5 --- Relationship of Microbial Community with Recolonization of Invertebrates --- p.135 / Chapter 5.1 --- Introduction --- p.135 / Chapter 5.2 --- Materials and Methods --- p.139 / Chapter 5.2.1 --- Study sites --- p.139 / Chapter 5.2.2 --- Microbial biomass carbon (C[subscript mic]) and nitrogen (N[subscript mic]) --- p.139 / Chapter 5.2.3 --- Fatty acid methyl esters (FAME) extraction --- p.140 / Chapter 5.2.4 --- Data analysis --- p.141 / Chapter 5.3 --- Results --- p.142 / Chapter 5.3.1 --- Fumigation-extraction --- p.142 / Chapter 5.3.2 --- Fatty acid methyl esters --- p.144 / Chapter 5.3.3 --- Relationship of microbial communities with physicochemical, vegetation and invertebrate parameters --- p.145 / Chapter 5.4 --- Discussion --- p.152 / Chapter 5.5 --- Conclusions --- p.159 / Chapter Chapter 6 --- Effects of Critical Factors on Invertebrate Communities --- p.160 / Chapter 6.1 --- Introduction --- p.160 / Chapter 6.2 --- Materials and Methods --- p.162 / Chapter 6.2.1 --- Experimental sites --- p.162 / Chapter 6.2.2 --- Critical factors selection and simulation --- p.163 / Chapter 6.2.3 --- Measurement of microclimatic characteristics --- p.165 / Chapter 6.2.4 --- Collection, sorting and identification of invertebrates --- p.166 / Chapter 6.2.5 --- Data analysis --- p.166 / Chapter 6.3 --- Results --- p.167 / Chapter 6.3.1 --- Microclimatic characteristics --- p.167 / Chapter 6.3.2 --- Invertebrate communities --- p.168 / Chapter 6.4 --- Discussion --- p.173 / Chapter 6.5 --- Conclusions --- p.178 / Chapter Chapter 7 --- General Conclusions --- p.180 / Chapter 7.1 --- Overall Discussion --- p.180 / Chapter 7.2 --- Limitation of the Present Study and Future Research --- p.184 / Chapter 7.3 --- Contributions to Our Knowledge --- p.188 / Reference --- p.192 / Appendices --- p.220

Wong Cheuk Yuet. / Thesis submitted in: July 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 223-233). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT --- p.iv / TABLE OF CONTENTS --- p.ix / LIST OF FIGURES --- p.xii / LIST OF PLATES --- p.xiv / LIST OF TABLES --- p.xv / Chapter CHAPTER 1 --- Introduction --- p.1 / Chapter 1.1 --- About the thesis --- p.1 / Chapter 1.2 --- Background of Hong Kong --- p.1 / Chapter 1.2.1 --- Geography --- p.1 / Chapter 1.2.2 --- Climate --- p.3 / Chapter 1.2.3 --- Vegetation and their distribution --- p.7 / Chapter 1.2.4 --- Floristic composition --- p.10 / Chapter 1.2.5 --- Urban development and forestry history --- p.11 / Chapter 1.3 --- Restoration of degraded lands --- p.13 / Chapter 1.3.1 --- Importance of restoration --- p.13 / Chapter 1.3.2 --- Sites for restoration --- p.16 / Chapter 1.3.3 --- Substratum for restoration in Hong Kong --- p.16 / Chapter 1.3.4 --- Revegetation --- p.19 / Chapter 1.4 --- Species for plantation --- p.20 / Chapter 1.4.1 --- Exotics vs. natives --- p.20 / Chapter 1.4.2 --- Fields of controversy --- p.23 / Chapter 1.5 --- Project objectives and significances --- p.26 / Chapter 1.6 --- Study sites --- p.27 / Chapter 1.6.1 --- Criteria for site selection --- p.27 / Chapter 1.6.2 --- Shek O Quarry and Lam Tei Quarry --- p.27 / Chapter 1.6.3 --- Rehabilitation of the quarries --- p.31 / Chapter 1.6.4 --- Site specificity and representativeness --- p.33 / Chapter CHAPTER 2 --- Characterization of CDG on Site --- p.37 / Chapter 2.1 --- Introduction --- p.37 / Chapter 2.2 --- Materials and methods --- p.39 / Chapter 2.2.1 --- Soil sampling --- p.39 / Chapter 2.2.2 --- Soil analysis --- p.40 / Chapter 2.3 --- Statistical analysis --- p.42 / Chapter 2.4 --- Results and discussion --- p.43 / Chapter 2.4.1 --- Characterization and comparison of soil stock between two sites --- p.43 / Chapter 2.4.2 --- Comparison between raw soil and grassed soil --- p.46 / Chapter 2.4.3 --- Comparison among phases --- p.49 / Chapter 2.4.4 --- Comparison with other studies --- p.56 / Chapter 2.4.5 --- Soil development in two quarries --- p.58 / Chapter 2.5 --- Conclusions --- p.59 / Chapter CHAPTER 3 --- Natives Performance in Revegetation on CDG - I. Common PlantationSpecies --- p.61 / Chapter 3.1 --- Introduction --- p.61 / Chapter 3.2 --- Materials and methods --- p.64 / Chapter 3.3 --- Statistical analysis --- p.66 / Chapter 3.4 --- Results and discussion --- p.68 / Chapter 3.4.1 --- Height and basal diameter at the beginning of study --- p.68 / Chapter 3.4.2 --- Relative growth rates of different ages --- p.72 / Chapter 3.4.3 --- Comparison between sites --- p.84 / Chapter 3.5 --- Conclusions --- p.89 / Chapter CHAPTER 4 --- Natives Performance in Revegetation on CDG ´ؤ II. the Neglected Species --- p.91 / Chapter 4.1 --- Introduction --- p.91 / Chapter 4.1.1 --- Seed dispersal and rehabilitation --- p.91 / Chapter 4.1.2 --- Conservation and rehabilitation --- p.92 / Chapter 4.1.3 --- Framework species --- p.93 / Chapter 4.2 --- Materials and Methods --- p.95 / Chapter 4.2.1 --- Species selection --- p.95 / Chapter 4.2.2 --- Planting area --- p.97 / Chapter 4.2.3 --- Planting scheme --- p.97 / Chapter 4.2.4 --- Planting protocol --- p.100 / Chapter 4.2.5 --- Field measurements --- p.102 / Chapter 4.3 --- Statistical analysis --- p.106 / Chapter 4.4 --- Results and discussion --- p.107 / Chapter 4.4.1 --- General performance of the planted species --- p.107 / Chapter 4.4.2 --- General inter-specific comparison --- p.116 / Chapter 4.4.3 --- Effect of aspect on seedling performance --- p.120 / Chapter 4.4.4 --- Effect of elevation on seedling performance --- p.140 / Chapter 4.4.5 --- Overall species evaluation --- p.147 / Chapter 4.5 --- Conclusions --- p.151 / Chapter CHAPTER 5 --- Further Exploration of Other Potential Pioneer Natives --- p.153 / Chapter 5.1 --- Introduction --- p.153 / Chapter 5.2 --- Materials and methods --- p.155 / Chapter 5.3 --- Results and discussion --- p.156 / Chapter 5.3.1 --- Inter-site comparison --- p.161 / Chapter 5.3.2 --- Inter-phase comparison --- p.163 / Chapter 5.3.3 --- Ranking of species --- p.171 / Chapter 5.3.4 --- Invaders for exploration --- p.171 / Chapter 5.4 --- Conclusions --- p.177 / Chapter CHAPTER 6 --- Performance of Five Natives under Different N:P Combinations --- p.180 / Chapter 6.1 --- Introduction --- p.180 / Chapter 6.2 --- Materials and Methods --- p.181 / Chapter 6.3 --- Statistical analysis --- p.185 / Chapter 6.4 --- Results and discussion --- p.186 / Chapter 6.4.1 --- Height --- p.186 / Chapter 6.4.2 --- Basal diameter --- p.193 / Chapter 6.4.3 --- Leaf number --- p.200 / Chapter 6.4.4 --- Total dry weight --- p.200 / Chapter 6.4.5 --- Aerial and underground dry weight --- p.202 / Chapter 6.4.6 --- "Chlorophyll florescence, stomatal conductance and transpiration" --- p.207 / Chapter 6.4.7 --- General species performance in treatments --- p.214 / Chapter 6.4.8 --- Comparison with seedling performance in field trial --- p.215 / Chapter 6.5 --- Conclusions --- p.216 / Chapter CHAPTER 7 --- General Conclusions --- p.217 / REFERENCES --- p.223 / APPENDIX I --- p.234 / APPENDIX II --- p.235 / APPENDIX III --- p.237 / APPENDIX IV --- p.238 / APPENDIX V --- p.241 / APPENDIX VI --- p.242

Ecological changes in soil covers were studied in terms of physical, chemical and biological properties in the three quarries. Results show that all soils were classified as sand loam in texture, and high bulk density and low total porosity were common problems. Soils were strongly acidic to moderately acidic in reaction. Organic C, total N, extractable NO3 - and extractable cations increased with increasing rehabilitation age, but others did not show similar trends. The results of mineral N flux in soil show that ammonification predominated over nitrification in TH and LT, while nitrification predominated in SO in wet season. In dry season, ammonification predominated over nitrification in all phases, except TH. Net N mineralization increased with age. The results of soil microbial study show that older sites had the highest total microbial abundance and biomass C and N, while those in younger sites were low. Metabolic abilities of soil microbes developed gradually with ages in SO, but TH and LT had the similar patterns of carbon source utilization. The group of G- bacteria dominated in all sites, in which cy19:0 represented more than 15% of the total extracted FAMEs. The group of fungi and AM fungi decreased with increasing ages in the three quarries. / Lacks of seed rain and seed bank were major factors limiting vegetation regeneration. Physical and chemical problems of cover soils are still severe even after 10 years of rehabilitation. Therefore, adding native species with fleshy fruits to attract birds, and leguminous species to assist in the buildup of nitrogen capital should be recommended. Application of organic composts should be considered by quarry contractors and managers during early rehabilitation period to improve soil structure and raise nutrient storage capacities. / To evaluate the ecological succession in the floristic composition and structure of closed quarries, studies of the current vegetation development and seed dynamics were carried out in the three quarries, namely Turret Hill Quarry (TH), Lam Tei Quarry (LT) and Shek O Quarry (SO). The floristic composition shows that the species richness and Shannon index were higher on older phases than other younger phases in the overstorey and understorey vegetation. Although planted exotic species dominated the overstorey at different phases, some native species became more dominant in the understorey, and the importance value of native species accounted for more than 50%. Seed rain results show that older sites had higher seed number and seed species than younger sites. In terms of number of seeds, half were dispersed by birds, while 23% and 27% were dispersed by wind and civets, respectively. Seed germination experiment shows that most species from all twelve woody species had higher germination in SO, though most emerging seedlings finally died under the field condition. In the soil seed bank study, high seed species and density were recorded on older sites. Non-woody species predominated on all phases of the three quarries, but some pioneer tree and shrub species were better represented on older sites. / Zhang, Hao. / Adviser: L.M. Chu. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 238-280). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Tsang Po-yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 173-191). / Abstract --- p.i / Acknowledgements --- p.iii / List of Tables --- p.iv / List of Figures --- p.v / List of Plates --- p.vi / List of Appendices --- p.vii / Chapter CHAPTER 1 --- INTRODUCTION / Introduction --- p.1 / Chapter 1.2 --- Conceptual framework --- p.3 / Chapter 1.3 --- Objectives --- p.15 / Chapter 1.4 --- Significance and scope of study --- p.17 / Chapter 1.5 --- Organization of the thesis --- p.18 / Chapter CHAPTER 2 --- STUDY AREA / Chapter 2.1 --- Location --- p.20 / Chapter 2.2 --- Climate --- p.23 / Chapter 2.3 --- Geology --- p.25 / Chapter 2.4 --- Soils --- p.26 / Chapter 2.5 --- Vegetation --- p.27 / Chapter 2.6 --- Restoration and floristic composition of the rehabilitated communities --- p.29 / Chapter 2.7 --- Post-planting maintenance of the rehabilitated communities --- p.31 / Chapter CHAPTER 3 --- RESTORATION OF SOIL CHEMICAL PROPERTIES / Chapter 3.1 --- Introduction --- p.33 / Chapter 3.2 --- Methodology --- p.37 / Chapter 3.2.1 --- Sampling --- p.37 / Chapter 3.2.2 --- Soil reaction --- p.37 / Chapter 3.2.3 --- Organic carbon --- p.37 / Chapter 3.2.4 --- Total Kjeldahl nitrogen (TKN) --- p.38 / Chapter 3.2.5 --- Mineral nitrogen (ammonium and nitrate nitrogen) --- p.38 / Chapter 3.2.6 --- Total phosphorus --- p.39 / Chapter 3.2.7 --- Available phosphorus --- p.39 / Chapter 3.2.8 --- Exchangeable cations --- p.39 / Chapter 3.2.9 --- Exchangeable A1 and H --- p.40 / Chapter 3.2.10 --- Carbon : nitrogen ratio --- p.40 / Chapter 3.3 --- Statistical analysis --- p.40 / Chapter 3.4 --- Results --- p.41 / Chapter 3.4.1 --- Chemical properties of the newly excavated soil --- p.41 / Chapter 3.4.2 --- Effect of rehabilitated communities on soil chemical properties --- p.42 / Chapter 3.4.2.1 --- Soil reaction and exchangeable acidity --- p.42 / Chapter 3.4.2.2 --- Organic matter and C:N ratio --- p.43 / Chapter 3.4.2.3 --- Total Kjeldahl N and mineral N --- p.43 / Chapter 3.4.2.4 --- Total and available phosphorus --- p.44 / Chapter 3.4.2.5 --- Nutrient cations --- p.44 / Chapter 3.4.3 --- Intra-layer differences of soil properties --- p.44 / Chapter 3.5 --- Discussion --- p.46 / Chapter 3.5.1 --- Properties of granitic soils awaiting restoration --- p.46 / Chapter 3.5.2 --- Effect of rehabilitated communities on soil acidity --- p.49 / Chapter 3.5.3 --- "Effect of rehabilitated communities on SOM, N and P" --- p.51 / Chapter 3.5.4 --- Changes in cation nutrients after rehabilitation --- p.57 / Chapter 3.5.5 --- Comparison of ecosystem rehabilitation with other studies --- p.60 / Chapter 3.6 --- Conclusion --- p.66 / Chapter CHAPTER 4 --- NITROGEN MINERALIZATION / Chapter 4.1 --- Introduction --- p.68 / Chapter 4.2 --- Methodology --- p.73 / Chapter 4.2.1 --- In situ incubation --- p.73 / Chapter 4.2.2 --- "Determination of N mineralization, uptake and leaching" --- p.75 / Chapter 4.3 --- Statistical analysis --- p.76 / Chapter 4.4 --- Results --- p.76 / Chapter 4.4.1 --- Temporal variations of NH4-N and N03-N in the rehabilitated sites --- p.76 / Chapter 4.4.2 --- "Net ammonification, nitrification and N mineralization in the rehabilitated sites" --- p.78 / Chapter 4.4.3 --- Uptake of mineral N in the rehabilitated sites --- p.80 / Chapter 4.4.4 --- Leaching loss of mineral N in the rehabilitated sites --- p.82 / Chapter 4.5 --- Discussion --- p.84 / Chapter 4.5.1 --- Nitrogen mineralization in the rehabilitated sites --- p.84 / Chapter 4.5.2 --- Uptake of mineral nitrogen in the newly rehabilitated sites --- p.92 / Chapter 4.5.3 --- Leaching loss of and mechanisms to conserve mineral nitrogen in newly rehabilitated sites --- p.96 / Chapter 4.6 --- Conclusion --- p.98 / Chapter CHAPTER 5 --- SOIL RESPIRATION IN NEWLY REHABILITATED BORROW AREA / Chapter 5.1 --- Introduction --- p.100 / Chapter 5.2 --- Methodology --- p.105 / Chapter 5.3 --- Statistical analysis --- p.107 / Chapter 5.4 --- Results --- p.107 / Chapter 5.5 --- Discussion --- p.109 / Chapter 5.5.1 --- Inherent microbial activities of the newly excavated soil --- p.109 / Chapter 5.5.2 --- Effects of young plantations on soil respiration --- p.110 / Chapter 5.5.3 --- Comparison of soil respiration between the rehabilitated sites and secondary Pinus massoniana woodland --- p.114 / Chapter 5.6 --- Conclusion --- p.116 / Chapter CHAPTER 6 --- GROWTH PERFORMANCE AND FOLIAR COMPOSITION OF REHABILITATED VEGETATION / Chapter 6.1 --- Introduction --- p.118 / Chapter 6.2 --- Methodology --- p.122 / Chapter 6.2.1 --- Growth performance measurements --- p.122 / Chapter 6.2.2 --- Chemical analysis --- p.123 / Chapter 6.3 --- Statistical analysis --- p.124 / Chapter 6.4 --- Results --- p.124 / Chapter 6.4.1 --- Growth measurements --- p.124 / Chapter 6.4.1.1 --- Height --- p.124 / Chapter 6.4.1.2 --- Stem basal diameter (SBD) --- p.127 / Chapter 6.4.1.3 --- Crown coverage --- p.130 / Chapter 6.4.2 --- Foliar nutrient composition of rehabilitated vegetation --- p.133 / Chapter 6.4.2.1 --- Total Kjeldahl nitrogen --- p.133 / Chapter 6.4.2.2 --- Total phosphorus --- p.134 / Chapter 6.4.2.3 --- Potassium --- p.136 / Chapter 6.4.2.4 --- Sodium --- p.137 / Chapter 6.4.2.5 --- Calcium --- p.138 / Chapter 6.4.2.6 --- Magnesium --- p.140 / Chapter 6.4.3 --- Element abundance among the rehabilitated species --- p.142 / Chapter 6.5 --- Discussion --- p.142 / Chapter 6.5.1 --- Species growth in the rehabilitated sites --- p.142 / Chapter 6.5.2 --- Role of nitrogen fixers in rehabilitating the borrow area --- p.144 / Chapter 6.5.3 --- Species selection in ecosystem restoration --- p.150 / Chapter 6.6 --- Conclusion --- p.154 / Chapter CHAPTER 7 --- CONCLUSION / Chapter 7.1 --- Summary of findings --- p.156 / Chapter 7.2 --- Implications of the study --- p.161 / Chapter 7.2.1 --- Ecosystem restoration strategy in Hong Kong --- p.161 / Chapter 7.2.2 --- Can native species establish on degraded land? --- p.164 / Chapter 7.2.3 --- Are the present findings transferable to other areas? --- p.167 / Chapter 7.3 --- Limitations of the study --- p.169 / Chapter 7.4 --- Suggestion for future studies --- p.171 / REFERENCES --- p.173 / APPENDICES --- p.192

Thesis (M.Sc.)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: It is well known that smoke and aqueous smoke solutions promote the germination of certain seeds. This has considerable practical implications for restoration in fire prone areas like the Cape fynbos. The aqueous smoke solution (more commonly known as smoke water) can be used in restoration projects to stimulate seeds to germinate faster so that a wide diversity of plants can be established rapidly. Smoke water is made using different methods and different plant materials. This inevitably results in different concentrations of smoke water. Although made in different ways, different smoke waters may all have an enhancing effect on seed germination. In this study, the germination of Grand Rapids lettuce seed was used to determine the differences between five different types of smoke water. Germination was done in a controlled environment, using through-flow germination boxes (patent no. ZA2000/1832, registered 1114/2000) instead of traditional petri dishes. The differences in the concentrations were determined using bioassays. A very strong concentration of smoke water damaged the seed and a very weak concentration did not have any enhancing effect on germination. The concentrations of the different smoke waters were compared to a standard smoke solution (the first smoke solution ever made, that of De Lange & Boucher (1990». The different concentrations of the smoke solutions were determined by comparing them to the standard, using a best fit line on the germination graphs. Each of the smoke solutions tested is given a "delb" rating (after De Lange & Boucher), with the standard smoke water being 1 delb. The delb value is used to determine the dilution factor for each smoke solution. It is concluded that the five smoke solutions tested all differed from each other emphasizing the need for quality control in commercial and experimental applications. / AFRIKAANSE OPSOMMING: Dit is wel bekend dat rook en vloeibare rook oplossings (rookwater) die ontkieming van sekere sade bespoedig. Dit het groot praktiese implikasies vir hervestiging in gebiede met gereelde vuur, soos die Kaapse fynbos. Die rookwater kan in hervestiginsprojekte gebruik word om sade te stimuleer om vinniger te ontkiem om sodoende 'n groot diversiteit van plante vinnig te vestig. Rookwater word op verskillende maniere en met verskillende materiaal vervaardig. Dit kan lei tot verskillende konsentrasies rookwater, alhoewel al die verskillende rookwaters 'n stimulerende effek op saadontkieming kan bewerkstellig. In hierdei studie is Grand Rapids slaai saad gebruik om die verskille tussen vyf verskillende rookwaters te ondersoek. Ontkieming was in 'n beheerde atmosfeer gedoen en deurvloei ontkiemingsbakke (patent nr. ZA2000/1832, geregistreer 11/4/2000) is gebruik, i. p. v. traditionele petri bakkies. Die verskille in konsentrasies is gemeet m. b. v. biotoetse. 'n Baie serk konsentrasie het die sade beskadig en 'n baie flou konsentrasie het geen stimulerende effek op ontkieming gehad nie. Die konsentrasie van die verskillende rookwaters is vergelyk teenoor 'n standaard rookwater (die eerste rookwater ooit gemaak, die van De Lange en Boucher (1990». Die verskillende rookwater konsentrasies is bepaal deur dit met die standaard te vergelyk m. b. v. 'n regressie lyn op die ontkiemingsgrafieke. Elke rookwater getoets kry dan 'n "delb" waarde (n. a. v. De Lange & Boucher), met die standard gelyk aan 1 delb. Die delb waarde word gebruik om die optimale verdunning van elke rookwater te bepaal. Daar word opgesom dat al die rookwaters getoets wel van mekaar verskil en dit beklemtoon die waarde van kwaliteits beheer in kommersiële en eksperimentele toepassings.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Worldwide, invasive alien plants (IAPs) alter aspects of invaded ecosystems including geomorphology, above-ground vegetation, soil seed banks and soil nutrient regimes, thereby affecting the long-term stability of ecosystems. In many cases these invasions call for various management interventions, including restoration. Effects of alien plant invaders on native ecosystems are widely acknowledged, but compared to terrestrial ecosystems, riparian habitats are poorly studied. Riparian habitats are inherently rich in biodiversity, but are particularly prone to invasion by IAPs because of their dynamic nature and because these ecosystems are affected by many anthropogenic activities. This enhances the proliferation of IAPs, especially trees such as Tamarix spp. (e.g. in the southwestern United States), Salix spp. (e.g. in Australia), and Australian Acacia spp. and Eucalyptus camaldulensis (in South Africa). Initiatives such as the Working for Water (WfW) programme in South Africa that are focusing on clearing IAPs, particularly in riparian zones, have reported much success in the short term, but ecosystem recovery remains limited. There is a poor understanding of the nature of the impacts of invasive trees, and of the opportunities that exist for ecosystem restoration. The objective of my thesis was to investigate the effects of the widespread invasions of Eucalyptus camaldulensis in riparian zones. Methodological constraints have been identified as one reason for limited success of restoration projects. Many studies examining the effects of IAPs used a comparative approach of uninvaded (reference) and invaded sites. However, this approach often fails to separate cause from effect. An experimental removal approach has been suggested as an alternative, but it is often inappropriate for large invasive trees owing to time and cost constraints. I used a comparative gradient approach, involving sampling along a continuum from uninvaded sites, and varying E. camaldulensis invasion densities categorised as “lightly”, “moderately” and “heavily” invaded (hereafter the gradient of invasion), each with four replicates (n = 16). This approach enabled me to detect trends that could be reliably attributed to invasion. Furthermore, my study attempted to provide a comprehensive understanding of the effects of IAPs in invaded ecosystems by considering various components of the ecosystem and integrating their feedback relationships to establish the net effects on ecosystem processes. The riparian zone is a unique ecosystem which provides an opportunity for such a multifaceted study examining and integrating the effects of invasive trees on riparian geomorphology, above-ground vegetation, soil seed banks, and soil properties. I studied the effects of E. camaldulensis invasion in riparian zones along the Berg River in the Mediterranean-type climate zone of the Western Cape, South Africa. I asked the questions 1) Are environmental conditions (i.e. the riparian environment created by geomorphological processes) altered by Eucalyptus invasion and if so, are these conditions less suitable for recruitment of indigenous species? 2. Has Eucalyptus invasion altered the composition of indigenous species (potentially limiting post-clearing propagule supply)? 3: How does Eucalyptus invasion change the composition of the riparian soil seed bank; and its potential to re-initiate ecosystem recovery? 4: Do soil properties (physical and chemical) change with Eucalyptus invasion? Data for all four questions were collected in the same sites to enable cross comparisons. For the first question, I employed photogrammetry techniques in a GIS and remote sensing environment to analyse repeated aerial photographs (1938 -2010) to reconstruct the invasion history and riparian geomorphology evolutionary dynamics. For the second and third questions, I compared richness, diversity, evenness and composition of resident above-ground and seed bank vegetation between uninvaded sites and the gradient of invaded sites. For the fourth question, I compared a set of variables describing physico-chemical properties in uninvaded sites to the gradient of invaded sites seasonally. Results of the geomorphology study showed that the riparian zone has been very dynamic over the 70 years, with a 13.5% net decrease in area. There was evidence of channel narrowing, riverbank steepening and river bed incision in areas that were densely invaded. No significant trends were detected in hydrometeorological data. The above-ground vegetation study revealed that species richness, diversity and structural attributes (e.g. height, relative cover and mean basal diameter) of native species decreased consistently along the invasion gradient. Invasion also altered native and alien plant species composition, both of which showed a high preference for lightly invaded sites. The seed bank study revealed that E. camaldulensis invasion had no significant effect on total and native species richness, diversity and evenness, however the effects were bigger on native than alien species. Alien species density was significantly higher than native species density. Invasion also influenced the composition of the native seed bank. However, native seed banks were more diverse than above-ground plant assemblages with some native fynbos species occurring only in the seed bank. In the soil study, I found that soil pH levels were significantly lower in invaded sites than in uninvaded sites in all seasons. Litter cover and thickness increased significantly with invasion intensity. Soil moisture decreased consistently with invasion intensity while temperature increased in winter and spring. Total macro, micro and available nutrients did not vary significantly along the invasion gradient (p > 0.05), but exchangeable cation content was significantly higher in uninvaded than in invaded sites, especially in winter and spring. Narrowing of river channel and steepening of river banks reduces the suitability of the riparian zone to perform certain ecological functions such as soil seed storage and providing space for vegetation to grow. This reduces opportunities for seedling recruitment and consequently reduces species diversity. Conversely, the reduction of species diversity in above-ground vegetation reduces seed input into the soil leading to depauperate soil-stored seed banks. The abundance of seeds of Acacia mearnsii in the soil-stored seed bank poses a threat of secondary invasions post clearing of E. camaldulensis if this is adopted as a management action. The study was successful in addressing the stated objectives. The transition from a native-dominated riparian plant community to a monoculture of E. camaldulensis over c. 50 years has resulted in marked changes to riparian geomorphology and above-ground vegetation, but has yet to radically change the total soil seed bank and soil nutrient concentrations. The findings offer support to the WfW clearing initiatives and show that potential for recovery of native species after removal of the invasive eucalypts still exists. This knowledge not only enhances effectiveness of restoration and long term management of riparian ecosystems, but also advances the field of riparian ecology and restoration. Further experimental work is needed to establish the mechanisms responsible for the changes associated with Eucalyptus invasion. The contribution of agriculture in shaping channel morphology also needs to be investigated. / AFRIKAANSE OPSOMMING: Die langtermyn stabiliteit van ekosisteme wêreldwyd word bedreig deur uitheemse indringer plante (UIPs) wat, onder andere, die geomorfologie, bo-grondse plantegroei, onder-grondse saadbanke en voedingstofstatus van ekosisteme kan verander. In baie gevalle word bestuursoperasies vir indringer plante vereis, en sluit onder andere herstel (restorasie) in. Die invloed van UIPs op inheemse ekosisteme word wyd erken, maar kennis oor oewerbank-habitatte, in vergeleke met ander terrestriële ekosisteme, skiet steeds tekort. Oewerbank-habitatte is inherent ryk aan biodiversiteit maar uiters sensitief vir indringing deur UIPs. Dit is weens die dinamiese aard van hierdie ekosisteme asook vele menslike aktiwiteite in hierdie tipe habitat. Dit dra by tot die vermeerdering van UIPs, veral bome wat byvoorbeeld insluit Tamarix (tamariske) (bv. in die suid-wes van die Verenigde State van Amerika), Salix (wilger) (in bv. Australië) en die Australiese Acacia (wattel) en Eucalyptus spesies (bloekom) in Suid Afrika. Inisiatiewe soos die Werk vir Water (WvW) program in Suid Afrika fokus juis daarop om UIPs vanuit oewerbank areas te verwyder, en alhoewel groot sukses in die kort termyn behaal is, is die herstel van ekosisteme steeds beperk. Daar is dus min inligting beskikbaar oor die impak van indringer bome en gevolglik ook oor geleenthede vir die herstel van hierdie ekosisteme. My tesis ondersoek die impak van die wydverspreide voorkoms van die indringer, Eucalyptus camaldulensis, in oewerbank-omgewings. Beperkte metodes is tans beskikbaar om die impak van indringer plante te ondersoek, en dit is geïdentifiseer as een van die oorsake vir die beperkte sukses van herstelprojekte. Baie studies ondersoek die effekte van UIPs deur natuurlike areas sonder enige indringer plante te vergelyk met areas waar UIPs voorkom. Hierdie tipe benadering kan ongelukkig, in meeste gevalle, nie onderskei tussen die oorsaak en die impak nie. ʼn Alternatiewe voorstel is om UIPs eksperimenteel te verwyder, maar is ongelukkig nie van toepassing op groot bome nie weens die tyd en kostes verbonde hieraan. Ek het gebruik gemaak van ʼn vergelykende-gradiënt benadering wat steekproefnemings langs ʼn geleidelike kontinuum van natuurlike areas sonder enige indringer plante na areas wat effens gematig, en erg ingedring is (hiernaas bekend as die indringer-gradiënt) deur die indringer, E. camaldulensis. Die steekproefnemings van elke kategorie van indringing (geen, effens, gematig en erg) is vier keer herhaal (n = 16). Hierdie benadering het my toegelaat om neigings te identifiseer wat met sekerheid toegeskryf kan word aan die teenwoordigheid van indringers. My studie het ook verder gemik om ʼn omvattende beskrywing van die impak van UIPs in ekosisteme met indringers te verskaf deur verskeie komponente van die ekosisteem, sowel as hul terugvoer-verhoudinge, in ag te neem, en sodoende die totale effek op ekosisteem prosesse te bepaal. ʼn Oewerbank is ʼn unieke ekosisteem wat ʼn geleentheid bied vir ʼn veelsydige studie wat die impakte van indringer bome op oewerbank-geomorfologie, bo-grond plantegroei, grond saadbanke en grondeienskappe, kan bestudeer en integreer. Ek het die impak van die teenwoordigheid van die indringer, E. camaldulensis in oewerbank areas langs die Bergrivier, wat ʼn Meditereense-tipe klimaat het, in die Wes Kaap, Suid Afrika, bestudeer. My studie het die volgende vrae gevra: 1) Is omgewings-omstandighede (bv. die oewerbank-omgewing geskep deur geomorfologiese prosesse) verander deur die teenwoordigheid van die Eucalyptus indringing, en indien wel, is hierdie omstandighede minder geskik vir inheemse spesies?; 2) Het die indringing van Eucalyptus gelei tot ʼn verandering in die samestelling van inheemse spesie gemeenskappe (moontlik beperkte plant voorplantings materiaal nadat die indringer verwyder is)?; 3) Hoe verander die indringing van Eucalyptus die samestelling van saad teenwoordig in die grond (saad bank) van die oewerbank en het dit die potensiaal om ekosisteem-herstel weer aan die gang te sit?; 4) Verander indringer Eucalyptus grond eienskappe (fisies en chemies)? Data vir al vier vrae is by dieselfde plek versamel om vergelykings te kan tref. Vir die eerste vraag het ek fotogrammetrie-tegnieke in ʼn Geografiese Inligting Stelsel (GIS) en afstandwaarnemings-omgewing toegepas om herhaalde lugfotos (1938-2010) te analiseer om die indringings geskiedenis sowel as die oewerbank se geomorfologiese evolusionêre dinamika saam te stel. Vir die tweede en derde vraag, het ek die aantal, diversiteit, gelykheid en samestelling van die bo-grond en saad bank plantegroei tussen natuurlike (geen indringers) en die gradiënt met indringers vergelyk. Vir die vierde en laaste vraag, het ek ʼn stel veranderlikes wat die fisies-chemiese eienskappe van die natuurlike omgewing sonder indringers beskryf, vergelyk met die eienskappe van die indringers gradiënt op ʼn seisoenale basis. Die resultate van die geomorfologiese studie wys dat die oewerbank omgewing baie dinamies was oor die afgelope 70 jaar met ʼn totale afname van 13.5% in rivieroewer-area in die gebied wat bestudeer is. Daar is ook bewyse vir ʼn vernouing van die kanaal, toename in die steilte van die rivierbank sowel as insnyding in die rivierbedding in areas wat ernstige indringing ervaar. Daar was geen beduidende neigings in die hidro-meteorologiese data nie. Die studie van die bo-grondse plantegroei het gewys dat die aantal plantspesies, diversiteit en strukturele kenmerke (bv. hoogte, dekking en gemiddelde basale diameter) van inheemse spesies afneem soos wat die indringings gradiënt toeneem. Indringing verander ook die inheemse sowel as uitheemse plant spesies samestelling. Beide inheemse en uitheemse spesies het areas wat slegs effense indringing wys, verkies. ʼn Studie van die saad bank (aantal sade in die grond) het gewys dat die indringer, E. camaldulensis geen merkwaardige invloed op die aantal, diversiteit en gelykheid van die totale en inheemse spesies teenwoordig gehad het nie. Die aantal uitheemse spesies was merkwaardig meer as die aantal inheemse spesies. Alhoewel indringing ook die samestelling van die inheemse saadbank beïnvloed het, was die inheemse saad bank, waarvan sommige spesies slegs daar voorgekom het, meer divers as die bo-grond plant samestellings. ʼn Studie van die grond het gewys dat die pH vlakke, afgesien van die seisoen, aansienlik laer is in die areas met indringers in vergeleke met areas sonder die indringers. Die hoeveelheid en dikte van plantmateriaal op die grond neem ook toe met ʼn toename in indringers. Die waterinhoud van die grond het afgeneem met ʼn toename in indringers en temperatuur het verhoog in beide winter en lente. Die totale makro- en mikrovoedingstowwe het nie merkwaardig gewissel saam met die indringingsgradiënt nie (p > 0.05), maar die uitruilbare katioon inhoud was aansienlik hoër, veral in die winter en lente-maande, in die areas sonder indringers in vergelyking met die areas met indringers. Vernouing van rivierkanaal en versteiling van rivieroewers verminder die geskiktheid van die oewersone om sekere ekologiese funksies te verrig soos grond-saadstoring en die verskaffing van ruimte vir plante om te groei. Dit verminder geleenthede vir werwing van saailinge en verminder gevolglik spesiediversiteit. Aan die ander kant, die vermindering van die spesiediversiteit in die bogrondse plantegroei verminder saadinsette in die grond en dit lei tot verarming van grondgestoorde saadbanke. Die oorvloed van sade van Acacia mearnsii in die grondgestoorde saadbank hou die bedreiging van sekondêre indringing in na die skoonmaak van E. camaldulensis indien dit wel as 'n bestuursaksie aangeneem word. Hierdie studie het die uiteengesette doelwitte suksesvol aangespreek. Die oorgang van ʼn oewerbank-gemeenskap wat hoofsaaklik uit inheemse plante bestaan na ʼn gemeenskap wat slegs uit E. camaldulensis bestaan, oor ʼn periode van ongeveer 50 jaar, het duidelike veranderinge tot gevolg gehad. Hierdie veranderinge is veral opmerklik in die oewerbank-geomorfologie en bo-grondse plantegroei, maar tot op hede is dit nog nie so opmerklik in die saadbank en grond-voedingstowwe konsentrasies nie. Hierdie bevindinge bied ondersteuning aan die WvW verwyderings-ondernemings en wys dat daar wel moontlike herstel van inheemse spesies kan wees na die verwydering van die indringer Eucalyptus. Hierdie kennis dra nie net by tot verhoogde effektiwiteit van herstelwerk en langtermyn-bestuursplanne nie, maar ook tot die navorsingsveld van oewerbankekologie en-herstel. Verdere eksperimentele navorsing word benodig om die moontlike meganismes wat verantwoordelik is vir die waargeneemde veranderinge, geassosieerd met Eucalyptus indringing, te verduidelik. Die bydrae van landbou tot die vorming van kanaal morfologie moet ook verder bestudeer word.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The loss and degradation of habitat is recognised as the greatest threat to invertebrate biodiversity. Restoration practices have the potential to reduce these impacts. The Seychelles giant millipede (SGM), Sechelleptus seychellarum, is a threatened and functionally important macro-detritivore endemic to the Seychelles granitic islands. The broad objective of this dissertation was to investigate selected aspects of the restoration ecology of the SGM, with the intention of making practical restoration recommendations that can be used to assist in the conservation of this species. This study was carried out on Cousine Island, Seychelles between 1998 and 2009, in the context of the large-scale plant community restoration that has taken place on the island. Large fluctuations in millipede population densities were found between 1998 and 2009. In 2002, 2003, 2005 and 2007 millipede densities were low, while densities were high in 1998 and 2009. Although the SGM is active all year round, its surface activity was positively correlated with rainfall, with density high during the high rainfall period (i.e. October – April) and low during the low rainfall period (i.e. May – September). Female:male:juvenile ratios were ~ 3:1:1. The implications are that translocations should preferably be done in years of high millipede densities and during the wet season. Alien coconut trees did not affect SGM density, but negatively affected its foraging behaviour, whereas bamboo stands negatively affected both its density and foraging behaviour. The SGM showed feeding preferences for Pisonia grandis and Ficus sp. leaf litter types. Alien bamboo and coconut pose a varied threat to the SGM, and their removal and replacement by indigenous forest species (e.g. P. grandis and Ficus sp.) should form part of an island’s restoration programme. SGM density was an order of magnitude lower in the restored area compared to the natural forest. In contrast, SGM physical condition improved significantly in the restored area, as vegetation structure increased. Furthermore, SGM behaviour in the restored area switched from a predominantly walking to a predominantly feeding behaviour over the study period, resulting in the forest restoration programme on Cousine increasing the foraging area of the SGM by 43%. SGM spatial density did not significantly correlate with edaphic and litter properties, but did positively correlate with the toposcape (i.e. elevation and granitic rock cover). Granite rock crevices in forest covered areas were important diurnal refuges for the SGM, as microclimate conditions in non-forest covered rock refuges were unsuitable. SGM physical condition was significantly lower in non-shaded crevices compared to those shaded by forest. Low granite rock cover in the restored forest limited the SGM colonisation of this area in large numbers, despite canopy cover in the restored forest being comparable with that in the reference natural forest. As most restoration practices are primarily vegetation-based, this study demonstrates that such an approach can be inadequate for restoring habitat for target invertebrates, as many species’ habitat requirements extend beyond that of vegetation. For the SGM, selecting restoration sites that already have abundant rock cover would be the most practical way to increase SGM habitat through forest restoration practices. Taking into consideration the habitat requirements of target invertebrates can help in setting or redirecting restoration goals and thus enhance the conservation value of such practices. / AFRIKAANSE OPSOMMING: Die verlies en agteruitgang van habitat word alom beskou as die grootste bedreiging var die biodiversiteit van ongewerweldes. Herstellingspraktyke kan hierdie agteruitgang verminder of stop. Die Seychelle Reuse Duisendpoot (SGM), Sechelleptus seychellarum, is 'n bedreigde en funksioneel belangrike makro-detritusvoeder wat endemies is aan die Seychelle graniet-eilande. Die breë doelstelling van hierdie verhandeling is die doen van navorsing om praktiese aanbevelings te kan maak om die habitat van die SGM tot so ‘n mate te herstel dat die spesie kan bly voortbestaan. Hierdie studie is tussen 1998 en 2009 uitgevoer op Cousine Island, Seychelles, nadat ‘n grootskaalse herstellingsfase van die plantgemeenskap plaasgevind het. Groot skommelings in duisendpootgetalle is waargeneem tussen 1998 en 2009, viz. duisendpootgetalle was laag in 2002, 2003, 2005 en 2007, terwyl dit hoog was in 1998 en 2009. Alhoewel die SGM gedurende die hele jaar aktief is, is hulle tog in groter getalle aanwesig in die tydperke met hoë reënval (Oktober-April) en laag in die droë tydperk (Mei-September). Die verhouding van wyfies, mannetjies en onvolwassenes was deurgaans ~ 3:1:1. Dit bring mee dat hervestiging van SGM verkieslik gedoen moet word wanneer hul populasies hoog is en dan ook in die nat seisoen. Uitheemse klapperbome het geen invloed op SGM getalle gehad nie, alhoewel hul voedingsgedrag negatief beïnvloed is deur dié bome. Bamboesbosse darenteen, beïnvloed beide populasiedigtheid en voedingsgedrag van SGM negatief. Verder is daar gevind dat Pisonia grandis en Ficus sp. blaardetritus voorkeurvoedsel vir SGM is. Die verwydering van die uitheemse bamboes en klapperbome en vervanging daarvan met inheemse woudspesies (P. grandis en Ficus sp.) moet dus deel vorm van die eiland se herstelprogram om sodoende die SGM te bevoordeel. Die SGM-bevolkingsdigtheid was 'n grootte-orde laer in die herstelde gebied in vergelyking met die natuurlike bos, maar hul fisiese toestand het aansienlik verbeter in die herstelde gebied, waarskynlik omdat die plantegroei as geheel verbeter het. Verder het die SGM se gedrag gedurende die studietydperk in die herstelde area oorgegaan vanaf ‘n oorwegend loopgedrag om na kos te soek, na ‘n oorwegend voedende gedrag. Die vervanging van uitheemse- met inheemse boomspesies op Cousine Island het dus die voedingsarea van SGM met tot 43% verhoog. Die ruimtelike SGM populasiedigtheid is nie beduidend beïnvloed deur blaardetritus nie, maar is wel positief beïnvloed deur die topografie (hoogte en granietbedekking). Bebosde graniet rotsskeure bied belangrike toevlugsoorde vir SGM gedurende die dag, terwyl die mikroklimaat wat deur onbebosde rotsskeure veroorsaak word, totaal ongeskik is vir SGM. Die fisiese toestand van SGM was ook aansienlik swakker in die nie bebosde rotsskeure teenoor dié van die bebosde areas. In herstelde bos met min granietskuiling was die herkolonisering van SGM ook getalsgewys laer alhoewel die bosbedekking vergelykbaar was met dié van die inheemse bos. Dit bewys dus dat herstellingspraktyke wat hoofsaaklik plantegroei teiken, nie altyd die teikenspesie bevoordeel nie, maar dat ‘n meer holistiese benadering wat alle habitatvoorkeure in ag neem, toegepas moet word. Om SGM te bevoordeel moet herstel areas vir herbebossing dus gekies word waar daar reeds genoegsame granietskuiling is. Deur die habitatvereistes van ongewerwelde teikenspesies in ag te neem kan die herstellingspraktyke meer oordeelkundig ingestel word en sodoende kan die bewaringswaarde van sulke praktyke verbeter word.