published_or_final_version / abstract / Geography / Doctoral / Doctor of Philosophy

M.Sc. / The decommissioning of mines and mining-related activities brings about the onset of rehabilitation. A legacy that most coal mines must address is the rehabilitation of the coal discard dumps that are generated by the beneficiation process of the raw coal. Rehabilitation involves the shaping and covering with a topsoil layer of these coal discard dumps. The topsoil layer is then revegetated to provide a stable form of protection against erosion. Considerations taken into account regarding the rehabilitation of coal discard dumps include the final slope angle, physical constraints i.e. railways or rivers, a source of topsoil and the grass species to be sown. Once the dump has been shaped, capped and seeded, regular applications of fertilizer take place for a defined period of time. This is to accelerate the growth of the grasses, as well as to stabilise the nutrient levels in the topsoil capping. Ingwe Mine Closure Operations (MCO), part of Ingwe Collieries Limited, is the business unit entrusted with the management and successful rehabilitation of Ingwe’s defunct operations. All of the coal discard dumps sampled in this study are found on such defunct operations. These coal discard dumps have been rehabilitated to a very high standard by MCO, and in most cases exceed the minimum requirements stipulated by law and guideline documents. This study and the results obtained from it reflect this. This study investigated, in terms of defined types of cover, whether or not there is a statistically significant difference between the: • six coal discard dumps from which data were collected; • five different defined slope aspects; • two groups of slope angles; and • slope angle and slope aspect in terms of cover. The data collected was analysed statistically, so as to determine whether significant differences (95 percentile confidence level), in terms of cover, exist. The purpose of this was to determine whether or not a preferred slope aspect or slope angle group could be identified for the six coal discard dumps sampled. By identifying a preferred slope aspect or slope angle group, companies could alter the design of operational or defunct dumps so as to maximise these. This would make the rehabilitation of the dump more sustainable and could possibly reduce aftercare costs. Through statistical analysis of the data collected it was determined that: • of the six coal discard dumps sampled, significant differences did exist between some of the dumps regarding basal cover, plant litter cover and bare ground. As each dump is different with its own specific micro-climate, this can be expected. The age of the dumps could also have played a role in terms of development; • of the five different defined slope aspects analysed, no significant differences existed between any of them; • of the two groups of slope angles analysed, no significant difference existed between them; and • no relationship between slope angle and slope aspect, in terms of cover, could be established. The analysis of the data collected was done by means of ANOVA one-way tests, coupled with Post Hoc Tests and Contrast Tables. The results of the statistical analysis were evaluated by the STATCON Department of the Rand Afrikaans University for accuracy. The data and the statistical analysis thereof were found to be satisfactory and correct. Various other statistical analyses were conducted on the data, but the results obtained from these tests were all the same as that of the original data analysis. These analyses included the Univariate Analysis of Variance, T-tests and Mann-Whitney tests.

As lianas são componentes característicos da Floresta Estacional Semidecidual, importantes para a estrutura e dinâmica deste ecossistema. Entretanto, são escassos os estudos sobre sua ecofisiologia, bem como sua utilização em programas de restauração ecológica. O objetivo deste estudo foi avaliar a ecofisiologia de sementes e juvenis de espécies de liana em relação às preferências ambientais para a regeneração e às variáveis envolvidas no uso dessas espécies na restauração ecológica via semeadura direta. Para isto, sementes de 11 espécies de lianas foram submetidas a quatro tratamentos: com e sem luz e com e sem alternância de temperatura, com 4 repetições de 25 sementes. O experimento sobre o crescimento de mudas foi realizado usando-se oito espécies de lianas submetidas a dois tratamentos: à pleno sol e sob sombra, com 12 repetições. Ao fim do experimento, o número de folhas foi contado. Posteriormente as folhas, o caule e a raiz de cada planta foram cortados, embalados, secos e pesados para obtenção da massa seca destes. Para o estudo da semeadura direta, 400 sementes de três espécies de lianas foram semeadas sob a copa de 48 indivíduos de quatro espécies arbóreas do dossel situadas em uma de floresta em restauração na margem da represa de abastecimento público do Município de Iracemápolis SP. Foi realizada avaliação mensal da emergência de plântulas por 210 dias. As espécies de lianas Bauhinia sp, Pithecoctenium echinatum e Urvillea laevis não necessitaram de luz e alternância de temperatura para germinar. Macfadyena unguiscati, Mucuna sp 1, Temnadenia violacea, Adenocalymma bracteatum e Hippocratea volubilis apresentaram fotoblastismo positivo, entretanto as duas últimas tiveram a porcentagem de germinação modificada pela alternância de temperatura. Peltastes peltatus, Aristolochia galeata e Cardiospermum grandiflorum apresentaram dependência de alternância de temperatura. Com relação à ecofisiologia de mudas, todas sobreviveram na sombra, sendo por isso consideradas como tolerantes ao sombreamento. Adenocalymma bracteatum, Cardiospermum grandiflorum e Macfadyena unguis-cati apresentaram maior crescimento à pleno sol para a maioria das variáveis analisadas, o que lhes confere vantagem competitiva em alta irradiância, como clareiras. Aristolochia galeata, Cissus sicyoides e Mucuna sp 2 apresentaram aumento de valor para poucas variáveis à pleno sol. Enquanto Mucuna sp 1 e Urvillea laevis não apresentam diferença de crescimento entre ambiente sombreado e à pleno sol, ou seja, a abertura de clareira não interfere na taxa de crescimento destas espécies. Com relação à semeadura direta, apenas duas espécies germinaram. Bauhinia sp apresentou emergência de plântulas muito baixa e Macfadyena unguis-cati ao contrário, apresentou germinação maior que a esperada nesta condição. Não houve diferença na emergência de plântulas entre os tratamentos. Assim, as lianas estudadas apresentaram diferentes respostas às condições ambientais típicas de clareiras, já que algumas espécies foram dependentes de luz/alternância de temperatura para germinar ou pleno sol para crescer melhor, e outros foram indiferentes a essas condições. Estes resultados indicam que as características ecofisiológicas de lianas devem ser considerados no planejamento de sua introdução em projetos de ecologia da restauração. / Lianas are important components of the structure and dynamics in seasonally dry forests, but there are few studies on their ecophysiology and use in restoration ecology. The objective of this study was to evaluate the ecophysiology of seeds and juveniles of species of liana in the preferences for environmental regeneration and the variables involved in using these species in direct seeding in restoration ecology. Seeds of 11 liana species were submitted to germination test in a combination of light and dark conditions with constant and alternating temperatures, with 4 replicates of 25 seeds per treatment. Seedlings growth was evaluated for eight liana species in conditions of full sun light and shading, with 12 repetitions per treatment. The plants were evaluated according to the dry mass of leaves, stem and root , as well to the number of leaves per plant. For the study of direct seeding, 400 seeds of three liana species were sowed under the canopy of four tree species present in a 20-year-old restored forest in Iracemápolis - SP. Evaluation was performed monthly and for a period of 210 days by accounting seedling emergence. The species Bauhinia sp, Pithecoctenium echinatum and Urvillea laevis did not require light and alternating temperature to germinate, but the species Macfadyena unguis-cati, Mucuna sp 1, Temnadenia violacea, Adenocalymma bracteatum and Hippocratea volubilis showed positive photoblastism and the species Peltastes peltatus, Aristolochia galeata and Cardiospermum grandiflorum required alternating temperatures. All seedlings survived to shading, but most of then grew better under full sun light. Only the species Bauhinia sp Macfadyena unguis-cati produced seedlings in the direct sowing, but at low emergence percentage and rate, which did not differ among tree species canopy. Thus, the studied lianas can have different responses to environmental conditions typical of forest gaps, as some species required light/alternating temperature to germinate and full sun light to grow better, and others were indifferent to such conditions. These results indicate that the ecophysiological characteristics of lianas should be considered when planning their introduction in restoration ecology projects.

O histórico processo de destruição da cobertura vegetal das florestas tropicais restringiu parte significativa das formações naturais deste bioma a fragmentos florestais pequenos e isolados. Nesse contexto, espécies ruderais de lianas podem se proliferar e rapidamente cobrir o dossel da floresta, prejudicando os indivíduos arbóreos e estagnando ou até mesmo regredindo os processos de sucessão florestal. O presente trabalho busca analisar as barreiras ecológicas que impedem a sucessão florestal em fragmentos florestais degradados dominados por lianas hiperabundantes, fornecer subsídios para estratégias de intervenção visando à restauração da estrutura e composição destes fragmentos e avaliar os efeitos iniciais do corte de lianas na dinâmica e crescimento da comunidade arbórea florestal. Para isso, foram instaladas 35 parcelas em um fragmento de floresta estacional semidecidual degradado e isolado pertencente ao bioma da Mata Atlântica, sendo cinco parcelas instaladas em setores menos degradados, e 30 em setores degradados dominados por lianas hiperabundantes. Destas 30 parcelas, cortaram-se todas as lianas em 20 parcelas, e avaliou-se a chegada de sementes, emergência e estabelecimento de plântulas e crescimento dos indivíduos arbóreos comparativamente entre parcelas com e sem manejo de lianas. Parâmetros da comunidade arbórea foram correlacionados com a densidade de lianas a fim de entender as relações entre estas formas de vida. O tempo necessário para o manejo de lianas foi quantificado e correlacionado com parâmetros da floresta a fim de entender quais fatores afetam o rendimento operacional desta atividade e o plantio de mudas foi testado em parcelas com e sem lianas, como técnica complementar ao manejo. Por fim, analisou-se o efeito do corte de lianas na produção de serapilheira, abertura de dossel, mortalidade dos indivíduos arbóreos e estocagem de carbono na parte aérea dos indivíduos arbóreos. Lianas não afetam a chegada de sementes ou a emergência de plântulas em fragmentos florestais degradados, porém diminuem o estabelecimento de plântulas pioneiras (provavelmente por sombreamento); no entanto, indivíduos arbóreos pioneiros compartilham habitat com as lianas, enquanto que espécies não-pioneiras têm a estrutura e diversidade de suas populações correlacionadas negativamente com a densidade de lianas. A quantidade de homens-hora para o corte de lianas em fragmentos degradados é muito maior que valores estimados para fragmentos florestais conservados, e é inversamente correlacionada com a densidade e área basal das lianas e positivamente relacionado com a densidade e área basal dos indivíduos arbóreos. O corte de lianas alterou a abertura do dossel no curto prazo e a produção de serapilheira, além de aumentar a estocagem de carbono para indivíduos arbóreos menores. O corte de lianas não afetou a mortalidade dos indivíduos arbóreos. Lianas hiperabundantes podem estagnar e até mesmo retroceder a sucessão florestal em fragmentos florestais e o corte de lianas é uma estratégia efetiva para recuperar estes processos. No entanto o manejo deve ser feito de forma contínua, dada a elevada resiliência comunidade de lianas ruderais. O plantio de mudas apresentou alta mortalidade e só é recomendando em casos de elevada abertura de dossel e baixa densidade de indivíduos arbóreos estabelecidos. / The historical human-mediated loss of tropical forest cover has beleaguered significant portions of these biomes in small and degraded forest remnants scattered on the landscape. In this context, ruderal liana species may proliferate and quickly dominate forest canopy, hindering tree individuals and arresting or even reversing forest succession. This study aims at analyzing the ecological barriers that halt forest succession in degraded forest remnants dominated by hyper-abundant lianas, providing ground to develop intervention strategies to restore structure and composition of these remnants and assess the early effects of liana cutting on the dynamic and growth of the forest tree community. We installed 35 plots in a degraded and isolated semideciduous seasonal forest remnant, from which five were installed in less degraded sectors of the forest remnant and 30 were installed in degraded sectors, dominated by hyper-abundant lianas. We chose 20 out of the 30 plots to undergo cutting of all lianas. We compared seed arrival, seedling emergence and establishment and growth of established adult tree individuals among control and liana cutting plots. Tree community parameters were correlated with liana density in order to understand the relation of these two life forms in the degraded forest. Time required, in man-hours, for liana cutting was quantified and correlated with tree and liana community parameters in order to provide ground for estimating labor requirements in similar situations; seedling planting was tested as a complimentary restoration technique. Finally, we assessed the early effects of liana cutting on canopy openness, litter production, tree mortality and carbon stored in the tree community. Lianas do not affect seed arrival or seedling emergence in degraded forest remnants, however, they do increase pioneer seedling mortality (probably through shading); at the same time, established pioneer individuals share habitat with lianas, while non-pioneers have the structure and diversity of their community negatively correlated with liana density. Manhours needed for liana cutting in degraded forest remnants are much higher than estimates for mature forests, and it is inversely correlated with liana density and basal area and positively correlated with tree density and basal area. Early effects of liana cutting included increased canopy openness, reduced litter production and increased carbon uptake by smaller trees. Liana cutting did not affect established trees mortality. Hyper-abundant lianas may stagnate and even reverse forest succession in degraded forest remnants and liana cutting is an effective strategy to recuperate sucessional processes. However, liana cutting must be carried out periodically, given the high resilience of ruderal lianas populations. Seedlings planting had high mortality and it is recommended only when canopy openness is high and density of established tree individuals is low.

Variation in the seasonal water level fluctuations of tropical and subtropical wetlands controls the production and concentration of aquatic fauna that support breeding wading birds. However, little is known about how particular components of the annual hydrologic cycle affect processes that control food availability and reproduction. This thesis identifies specific mechanisms responsible for transforming wet season prey standing stock into dry season prey concentrations, links landscape hydrological patterns to wading bird nesting, and presents a predictive model of Wood Stork nesting. I examined the supoort for several a priori hypotheses of factors affecting wading bird prey concentrations and wading bird nest effort. Factors affecting the concentration and vulnerability of prey were important for transferring secondary production to higher trophic levels. Receding water levels, microtopographic variation, and high standing stocks of prey were critical for generating pulses of food availabiltiy to meet the high energy requirements of breeding predatory birds. / by Bryan A. Botson. / Thesis (M.S.)--Florida Atlantic University, 2012 / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

A restauração da Mata Atlântica tem sido considerada prioridade nas iniciativas de manutenção da biodiversidade. Adicionalmente, há consenso de que os parâmetros para avaliação da restauração ecológica devem mensurar o retorno de funções ecológicas. O estudo de interações planta-visitante floral pode ser um caminho adequado para avaliar a eficiência das práticas de restauração, visto que estas interações desempenham função crítica na dinâmica e diversidade da comunidade. Variações na diversidade de espécies de plantas e de seus visitantes florais podem alterar a freqüência de interação entre as espécies, definir a estrutura das redes de interação, determinando os níveis de generalização e especialização na comunidade. Neste contexto, a tentativa de restaurar florestas tropicais pela adição de espécies arbóreas pode ter efeitos sobre a estrutura, estabelecimento de grupos funcionais e níveis de generalização na rede de interação entre flores e visitantes florais. O objetivo principal deste trabalho é o de comparar redes de interação planta-visitante floral em florestas tropicais restauradas após 5 anos do plantio das arbóreas, florestas regeneradas naturalmente e remanescentes de floresta atlântica em uma área sob domínio da Mata Atlântica no sudeste do Brasil. Para atingir esse objetivo, essas florestas foram comparadas quanto suas diversidades estruturais e funcionais em relação aos seguintes aspectos: 1) Riqueza e atributos de história de vida (formas de vida, sistemas sexuais, modos de polinização e de dispersão); 2) redes de interação plantavisitante floral; 3) Grau de generalização e especialização das redes de interação; 4) robustez quanto à perda de espécie em redes de interação, e 5) Formação de grupos funcionais seguindo características florais e de freqüência de visitas. Para cada aspecto avaliamos a contribuição das espécies plantadas. Florestas restauradas tiveram a maior riqueza de espécies em flor, porém com menor similaridade florística com outras florestas locais. A similaridade em abundâncias relativas de arbustos e lianas com outras categorias de florestas indicou a inclusão de outras formas de vida além de árvores nas florestas restauradas. Porém, a alta abundância relativa de árvores nas florestas regeneradas naturalmente também indicou o potencial de regeneração natural em florestas 15 degradadas. A maior diversidade de modos de polinização biótica e de dispersão de sementes nas florestas restauradas veio das plantas regenerantes espontaneamente. Não houve diferenças significativas quanto às métricas de redes de interação flores e visitantes entre os tratamentos, porém houve uma tendência de maior especialização dessas interações nas florestas nativas e maior robustez à perda de espécies em florestas restauradas. Além disso, plantas regenerantes espontaneamente receberam significantemente mais visitas nas florestas regeneradas naturalmente do que em florestas restauradas, sugerindo que árvores plantadas podem estar reduzindo visitação às flores da vegetação regenerante espontânea, possivelmente competindo por visitantes florais. Em relação à diversidade funcional, 21 grupos funcionais baseados em atributos florais foram estabelecidos entre todas as espécies em flor, onde as espécies da floresta restaurada dominaram três grandes grupos e a floresta nativa apresentou representantes distribuídos equitativamente pelos grupos, sem dominância. Pólen foi a variável que mais contribui para diferenciação dos grupos. As espécies plantadas formaram grupos funcionais exclusivos nas florestas restauradas, contribuindo para uma maior diversificação em atributos funcionais florais em tais comunidades, porém não mais do que a diversificação funcional trazida pelas plantas regenerantes espontaneamente. Redes de interação entre grupos funcionais de plantas e categorias taxonômicas de visitantes reforçaram que os visitantes florais parecem não seguir fielmente grupos funcionais por atributos florais. Considerando que as florestas regeneradas naturalmente apresentaram alta abundância relativa de árvores, não apresentaram diferenças significativas quanto às métricas de redes de interação planta-visitantes florais com as florestas restauradas e que a regeneração natural na região estudada ocorre em grande intensidade, sugerimos que seja dada importância relevante às plantas regenerantes espontaneamente em projetos de restauração. Cabe ressaltar que avaliamos restauração após 5 anos da implantação. Assim, todas as conclusões tiradas deste estudo necessitarão ser acompanhada em estudos futuros. / Restoration of the Brazilian Atlantic Forest has been considered priority in initiatives to maintain biodiversity. Additionally, there is consensus that the parameters to evaluate restoration should address the return of ecological processes. The study of flower-visitor interactions can be a reasonable way to evaluate restoration practice, considering that these interactions have critical role in the dynamics and diversity of communities. Variations in the diversity of plant species and their flower visitors could modify frequency of interactions between species; define the structure of interaction networks, and determine generalization and specialization levels in the community as well. In this context, the attempt to restore tropical forests by planting native trees can affect the structural and functional diversity and generalization level in flower-visitor networks. The main objective of this research is to compare flower-visitor networks in 5-year-old restored forests, naturally regenerated forests and native forests in an Atlantic Forest domain in southeastern Brazil. We compared these forests in relation to: 1) Richness of species and life history traits (growth form, sexual system, biotic pollination modes and dispersal modes); 2) Flower-visitor networks; 3) Generalization and specialization levels in ecological networks; 4) Robustness to species loss in ecological networks; and 5) Functional groups by floral traits and visitation frequencies of flower visitors. We evaluated the contribution of planted species on each of these aspects. Restored forests had the highest floristic richness of species in flower, but little floristic similarity with other native local forests. Similarity in the relative abundance of shrubs and lianas among habitat categories indicated the possibility of annexation of other life forms than trees in restored forests. But the presence of high relative abundance of trees in the naturally regenerated forests also indicated the potential of natural regeneration of the degraded forests. Biotic pollination and dispersal modes tended to be more diverse in restored forests, but it comes as a result of the addition of spontaneously regenerated plants to this forest. There were no significant differences in the metrics of flower-visitor networks between forest categories, although there was a trend towards high specialization of 17 interactions between flower and visitors in native forests and high robustness of species loss in restored forests. In addition, spontaneously regenerated plants received significantly more visits in the naturally regenerated forests than in restored forests, suggesting that the planted trees may reduce the visitation to the spontaneously regenerated vegetation, possibly by competing for flower visitors. With regard to functional diversity, 21 functional groups based on floral traits were recognized when all species in flower was pooled. Species of restored forests were dispersed mainly among three groups, while species from native forests were spread among all groups with almost the same number of species per group. Pollen was the variable that most contributed for grouping species. Planted trees species formed exclusive functional groups, contributing for higher diversification of floral trait to the community. However, this diversification was not higher than provided by spontaneous regenerated plants. Interaction networks between plant functional groups and taxonomic categories of flower visitors ensured that flower visitors do not seem to follow the grouping formed by floral traits. Considering that naturally regenerated forests had high relative abundance of trees, were not different from restored forests in relation to network metrics and that natural regeneration was intense in the region, we suggest paying relevant attention to spontaneous regenerated plants in restoration projects. We would like to point out that we evaluated five-year-old restored forests and there is still need to track these forests in the future.

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

abstract: Biological soil crusts (biocrusts) are topsoil communities of organisms that contribute to soil fertility and erosion resistance in drylands. Anthropogenic disturbances can quickly damage these communities and their natural recovery can take decades. With the development of accelerated restoration strategies in mind, I studied physiological mechanisms controlling the establishment of cyanobacteria in biocrusts, since these photoautotrophs are not just the biocrust pioneer organisms, but also largely responsible for improving key soil attributes such as physical stability, nutrient content, water retention and albedo. I started by determining the cyanobacterial community composition of a variety of biocrust types from deserts in the Southwestern US. I then isolated a large number of cyanobacterial strains from these locations, pedigreed them based on their 16SrRNA gene sequences, and selective representatives that matched the most abundant cyanobacterial field populations. I then developed methodologies for large-scale growth of the selected isolates to produce location-specific and genetically autochthonous inoculum for restoration. I also developed and tested viable methodologies to physiologically harden this inoculum and improve its survival under harsh field conditions. My tests proved that in most cases good viability of the inoculum could be attained under field-like conditions. In parallel, I used molecular ecology approaches to show that the biocrust pioneer, Microcoleus vaginatus, shapes its surrounding heterotrophic microbiome, enriching for a compositionally-differentiated “cyanosphere” that concentrates the nitrogen-fixing function. I proposed that a mutualism based on carbon for nitrogen exchange between M. vaginatus and its cyanosphere creates a consortium that constitutes the true pioneer community enabling the colonization of nitrogen-poor, bare soils. Using the right mixture of photosynthetic and diazotrophic cultures will thus likely help in soil restoration. Additionally, using physiological assays and molecular meta-analyses, I demonstrated that the largest contributors to N2-fixation in late successional biocrusts (three genera of heterocystous cyanobacteria) partition their niche along temperature gradients, and that this can explain their geographic patterns of dominance within biocrusts worldwide. This finding can improve restoration strategies by incorporating climate-matched physiological types in inoculum formulations. In all, this dissertation resulted in the establishment of a comprehensive "cyanobacterial biocrust nursery", that includes a culture collection containing 101 strains, isolation and cultivation methods, inoculum design strategies as well as field conditioning protocols. It constitutes a new interdisciplinary application of microbiology in restoration ecology. / Dissertation/Thesis / Doctoral Dissertation Liberal Studies 2019

Ecological conservation and restoration in the anthropocene must struggle with overlapping drivers of biodiversity and cultural loss; ruptures of the ecological environment mirror ruptures of human relationships with nature. And yet technology cannot remove humans from nature; technological and infrastructural reconfigurations of nature create new vulnerabilities and risks for humans and ecosystems alike. How can conservation and restoration science productively grapple with complex infrastructure systems and decision-making processes as biophysical and social drivers of ecosystem change? Using dam removals in the USA and in the Mid Columbia River region of the Pacific Northwest, this dissertation develops a conceptual framework for Social, Environmental, and Technological Systems (SETS), and applies it at three spatial and temporal scales to the practice of dam removal as a river restoration strategy. Drawing upon existing data sets, as well as biophysical, document, survey, and interview data this dissertation addresses how dam removals have functioned in the context of the social histories of river restoration programs, examines how these restoration programs must continue to renegotiate the human relationships with nature through the infrastructure systems that enable certain forms of existence while precluding others. Of particular interest is how restoration programs have increasingly functioned to deliver novel infrastructure solutions, while ignoring longer-term changes in ecological structure and function due to infrastructure development; in other words, the infrastructural work of restored ecosystems, and the infrastructural blind spots of restoration programs. How restoration planning considers, or does not consider, infrastructural blind spots, is indicative of not only the biophysical drivers of threatened and endangered species loss, but also the political dynamics of decision making at large, and the power-knowledge relationships constituting legitimate and relevant knowledge in the decision making space. In the Pacific Northwest, there appears to be a tipping point of social convention in centering treaty rights and obligations vis-a-vis ongoing processes of colonization and institutionalized scientific expertise. Ecological restoration will only be successful if it addresses both engineered infrastructures and social justice.

The prairie ecosystem of the American Midwest has long been depicted as a "lost landscape." Two-hundred years of Euro-American settlement has degraded the ecological prairie through systematic removal of native grasses and forbs, replacement with nonnative and invasive plant species, disruption of longstanding disturbance regimes (such as prairie fires), and the fragmentation of ecosystem connectivity. The prairie's depiction in art, literature, history, politics, and our national environmental discourse, collectively referred to in this study as the "cultural prairie," has not fared much better. Beginning in the early nineteenth-century, explorers and soldiers, writers and artists, settlers and promoters perpetuated an image of the "vanishing prairie" in travel narratives prolifically published for consumption by a burgeoning American readership. As the "vanishing prairie" emerged as the accepted image of the prairie, narratives depicting its disappearance from the landscape became self-fulfilling prophecies. Language, and narrative in particular, thus contributed to the degradation of the ecological prairie. Narratives of the "vanishing prairie" are characterized by what Anishinaabe writer Gerald Vizenor terms "absence, nihility, and victimry." One remedy to these fatalistic narratives is Vizenor's notion of "survivance," which he defines as "an active sense of presence over absence, deracination, and oblivion; survivance is the continuance of stories" ("Aesthetics of Survivance," in Survivance: Narratives of Native Presence, ed. Gerald Vizenor [Lincoln, NE: University of Nebraska Press, 2008], 1). Though Vizenor uses the term survivance principally to recover the stories, traditions, and identities of Native American cultures from Euro-American "simulations of dominance," his critical inquiries are more broadly applicable to the exploitation of the environment by many of the same policies, agents, strategies, and technologies that were put to use to propagate and promote state-sponsored ideologies of uniformity, homogeneity, and monoculturalism throughout the American Midwest. "Prairie survivance" is thus an attempt to make the prairie a presence, not an absence, in mainstream environmental discourse and debate, including the study of American literature and the fields of environmental criticism (or ecocriticism), place studies, and cultural geography. My argument begins with a critique of Euro-American travel narratives popularized throughout the nineteenth-century by the likes of Washington Irving, George Catlin, "Buffalo Bill" Cody, and others. These travel narratives perpetuated the trope of the "vanishing prairie" by employing stock images and narrative techniques, none more pervasive than the bison hunt. Specifically, the dramatic hunt sequences of these travel narratives reinforced the eradication of the bison from the ecological prairie. However, the consequences of these narratives are not limited to the time of their writing; instead, the "lost landscape" image of the prairie remains persistent to this day as a direct result of its misrepresentation in the travel literature of the nineteenth century. The second half of my argument entails a reading of counternarratives that envision a much different past, present, and future for the prairie. The bison's recovery in narratives by Luther Standing Bear, James Welch, N. Scott Momaday, and Mary Oliver is one example in which the fate of the prairie is not limited to its inevitable demise. Moreover, I have coined the term "aesthetics of restoration" to describe the prairie's presence in the work of Aldo Leopold, Paul Gruchow, Annie Proulx, and Linda Hogan (among others), each of whom overturns nihilistic images of the prairie as a "lost landscape" by writing about its restoration and permanent return to the landscapes of the American Midwest. Narrative's potential for healing is realized in these examples, a cornerstone of narrative ethics.