Thesis (M.S.)--University of Wisconsin, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-63).

The restoration of drained afforested blanket bogs is a cost-effective management approach in peatland conservation that aims to restore key ecosystem functions such as biodiversity and carbon storage and sequestration. Although arthropods are one of the most abundant and widespread animal groups in peatlands, little research has been carried out to assess their response to the variety of restoration management techniques that have been applied in afforested blanket bogs. We assessed the effectiveness of restoration by investigating the restoration trajectory of arthropod assemblages in formerly afforested blanket bog. We first looked at the long-term trajectory of arthropod assemblages, as well as carabid and moth taxa, in a chronosequence of tree-felled/drain-blocked treatments. Then, we looked at the short-term response of arthropod and carabid assemblages in treatments under varying regimes of brash management. General arthropod assemblages, and the functional traits of carabids and moths, were used to further investigate what type of biotic and abiotic parameters might be of importance during restoration. Lastly, we looked at potential biondicators of restoration progress to be used in restoration monitoring. The long-term restoration trajectory showed that typical bog assemblages are yet to be achieved due to persistence of generalists, as well as absence of bog specialists. Divergence in assembly trajectory was found at 18 years since onset of restoration, suggesting the emergence of an alternative state. Short-term restoration shows that brash might act as temporary habitat at early stages, where carabids favour lower structurally complex habitats than arthropods. Broad patterns of moth distribution revealed trait syndromes associated with blanket bog, whilst abiotic components such as vegetation structure, temperature, plot perimeter and blanket bog connectivity were found to be key for arthropod assemblages. The latter suggests potential legacy and edge effects associated with the restoration process. Arthropods and carabids showed high habitat specificity and fidelity, providing high bioindicator potential for restoration progress. This thesis shows that typical bog arthropod assemblages largely rely on habitat microstructure, particularly Sphagnum mosses, and associated microclimates for survival. Management can provide temporary refuge for arthropods, but the re-establishment of peat-forming vegetation and water table depth is essential for the return of typical bog assemblages. Though trade-offs might be encountered in the long-term restoration of peatland functions, a restoration framework is provided for the monitoring of arthropod assemblages.

It is estimated that 10-15% of the worlds blanket bog occurs in British uplands, although this is at risk due to land-use change, climate change and tourism. Currently, several types of management and restoration work are underway in many upland areas to prevent further degradation (RSPB, 2007). Within the RSPB Vyrnwy reserve a five year management plan is currently in progress. The area contains numerous drainage ditches created to improve the quality of grazing. This has lead to a loss of blanket bog vegetation, as the drains facilitate the removal of water, across the site (Worrall, et al, 2007). To encourage the reformation of blanket bogs these ditches are now being dammed. Approximately 4500 ha will be treated over the five year period, with an estimated 18km of drains blocked each year. Previous studies suggest this will lead to increases in CH4 flux from peatlands (Price, 1997). CH4 flux rates at difference water tables in Calluna and Eriophorum cores from Lake Vyrnwy were measured in a controlled environment. It was concluded that, in the short term, water table manipulation does influence net CH4 flux rates in peat cores from this system. In Eriophorum cores a positive flux was recorded at the high water table but not where the water table was 10cm lower. A 13C-CH4 approach was also applied to more accurately determine CH4 oxidation rates. These results indicated CH4 oxidation was occurring at all water tables and in both vegetation types, even when a positive net flux was seen. It was established that comparing both 12+13C-CH4 flux rates, and 13C-CH4 oxidation rates provided more information on the impacts of water table manipulation than relying on flux data alone. Data presented suggests that gripping at Lake Vyrnwy has the potential to decrease rates of CH4 oxidation across the site.

This study investigated the effect of excess carbon loading in the anoxic reactor on the nitrogen removal capacity of a biological pre-denitrification system for the treatment of a high ammonia leachate. The influent leachate was low in degradable organic carbon, thus an external carbon source was needed for denitrification requirements. Four different carbon sources were studied: methanol, glucose, acetate, and a waste brewer's yeast. The carbon loading was increased over the duration of the experimental period. The COD:NOx added to the anoxic reactor reached more than three times the carbon loading required to just achieve complete denitrification. All four carbon sources were found to support denitrification, but the glucose system showed erratic behaviour and ultimately failed after reaching a CODrNOx loading of about 23:1. The system using acetate appeared to require the least amount of COD:NOx (5.9:1) for complete denitrification, followed closely by methanol (6.2:1), then the yeast waste (8.5:1), and finally by glucose (9:1). Carbon breakthrough, the bleeding of carbon from the anoxic reactor into the aerobic reactor, was observed to occur just after complete denitrification was reached. The excess carbon did not appear to have any effect on denitrification, except in the case of the glucose system. The unit nitrification was found to decrease as the CODrNOx was increased, even though the ammonia removal remained at 100%. The decrease in nitrification, with respect to the COD:NOx, was most pronounced in the system that used methanol, and about equal in the other three systems. The cause of the decrease in nitrification is suspected to be due to increased ammonia assimilation by the heterotrophs rather than an inhibition of the nitrifiers. Nitrification ceased in the glucose system, but was restored within 12 days after the glucose addition was halted. The cause of the failure of the nitrogen removal process in the glucose system was not determined. Nitrite accumulation was observed in all the systems except the methanol system. The yeast waste system had nitrite accumulation in the aerobic reactor at C0D:N0x loadings over 25:1. Free ammonia inhibition of Nitrobacter is suspected to be the cause of aerobic nitrite buildup. The glucose and acetate systems had nitrite buildup in the anoxic reactor until complete denitrification was achieved. Facultative anaerobic bacteria are suspected of causing this nitrite accumulation. This theory was supported by observations in the glucose system, such as low anoxic pH; this may have been due to volatile fatty acids produced from fermentation. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

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Etudes écologique, floristique, phytosociologique et ethnobotanique de la forêt marécageuse de Lokoli (Zogbodomey – Bénin)<p><p>La forêt marécageuse de Lokoli, située dans le sud du Bénin est une formation non protégée, bien qu’elle soit la seule forêt marécageuse avec un cours d’eau permanent connue en Afrique de l’Ouest. Pour envisager une prise de décision de conservation et de protection de cet écosystème forestier, il est important de disposer d’une meilleure connaissance de sa flore, de sa végétation et de son fonctionnement. C’est dans ce cadre que la présente étude a été envisagée. Les données collectées concernent le milieu naturel, la structure de la forêt, la régénération naturelle des espèces et les usages faits des Produits Forestiers Non Ligneux (PFNL).<p>Le milieu naturel se compose d’un substratum acide (pH variant de 3,5 à 5,5) et argilo-sableux. Le cortège floristique de cette forêt est composé de 241 espèces réparties en 185 genres et 70 familles dont des espèces endémiques (Uapaca paludosa) ou en danger (Hallea ledermannii), Nauclea xanthoxylon, etc. <p>Sept groupements végétaux ont été identifiés (forêt primaire inondée à Alstonia congensis et Xylopia rubescens, forêt secondaire inondée à Ficus trichopoda et Spondianthus preussii et raphiale à Raphia hookeri et Anthocleista vogelii en forêt ;forêt ripicole à Alchornea cordifolia et Mitragyna inermis, savane marécageuse à Ficus asperifolia et Paullinia pinnata ;prairie marécageuse à Cyclosorus gongylodes et Polygonum pulchrum et enfin prairie marécageuse à Rhynchospora corymbosa et Ludwigia abyssinica en lisière) avec des précisions sur leurs caractéristiques floristiques, biologiques, phytogéographiques et écosociologiques. Les mésophanérophytes sont abondants en forêt alors qu’en lisière, ce sont les microphanérophytes qui sont les plus nombreux. Ces groupements constituent un refuge pour de nombreuses espèces animales dont Barboides britzi, poisson déterminé pour la première fois en 2006. D’après cette étude, on note une bonne régénération des espèces forestières malgré une recrudescence des trouées liées à l’installation de champs de Colocasia esculenta. <p>Parmi les 75 espèces, source de PFNL recensées, les produits et sous-produits issus de Raphia hookeri sont les plus exploités car ils constituent pour les populations riveraines d’importantes sources de revenus. Ces PFNL sont exploités à Lokoli pour plusieurs usages à savoir l’alimentation, l’emballage, boisson alcoolisée, recettes médicinales, construction, etc. Le nombre de pieds de Raphia hookeri saignés par an est de 15.452 par 320 exploitants dont 148 cueilleurs, 81 transformateurs et 91 commerçants ;ce qui fournit aux exploitants des revenus de l’ordre de 28.000 à 159.000 FCFA (42,7 à 242,4 euros) par mois et par exploitant, sans oublier les autres activités menées par les riverains dans cet écosystème. On note une forte pression anthropique sur cette formation qu’il est donc urgent de protéger. <p>En effet, elle dispose d’importants atouts qui militent en faveur de sa conservation. Elle abrite des espèces végétales et animales rares, endémiques, vulnérables et en danger (inscrites sur la liste rouge de l’UICN), telles que :Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. La forêt marécageuse de Lokoli joue un rôle de refuge pour toutes ces espèces qui y trouvent leur niche écologique. Sur le plan socio-économique, la FML fournit aux populations riveraines des revenus pour leur subsistance. Toutes ces potentialités font d’elle une Forêt à Haute Valeur pour la Conservation (FHVC) et elle pourrait constituer une véritable réserve de biosphère dans le Sud-Bénin.<p> <p>Ecological, floristic, phytosociological and ethnobotanical studies of the swamp forest of Lokoli (Zogbodomey - Benin)<p><p>The swamp forest of Lokoli, located in the south of Benin, is a non-protected area, although it is the only swamp forest in West Africa accompanied by a river which always contains water. To be able to make decisions concerning the conservation and protection of this forest ecosystem, it is important to have a better knowledge of its flora, its vegetation and its ecology and dynamics. It is within this framework that the present study was considered. The data that were collected relate to the natural environment, the structure of the forest, the natural regeneration of the species and the uses of the Non Timber Forest Products (NTFP).<p>The natural environment is composed of a substratum which is acid (pH varying from 3.5 to 5.5) and loamy-sandy. The floristic composition of this forest is composed of 241 plant species from 185 genera and 70 families.<p>Seven vegetation types were identified: 1. Inundated primary forest with Alstonia congensis and Xylopia rubescens; 2. Inundated secondary forest with Ficus trichopoda and Spondianthus preussii; 3. Raphia forest with Raphia hookeri and Anthocleista vogelii; 4. Riparian forest with Alchornea cordifolia and Mitragyna inermis; 5. Marshy savanna with Ficus asperifolia and Paullinia pinnata; 6. Marshy savanna with Cyclosorus gongylodes and Polygonum pulchrum; and 7. Marshy savanna with Rhynchospora corymbosa and Ludwigia abyssinica. Precise details are given on their floristic, biological, phytogeographical and phytosociological characteristics. The mesophanerophytes are abundant in forest whereas at forest edges the microphanerophytes are most numerous. These vegetation types constitute a refuge for many animal species, for example Barboides britzi, a species of fish first identified in 2006. This study noted a good regeneration of forest species, in spite of disturbance related to the installation of fields of Colocasia esculenta.<p>About 75 investigated NTFP are exploited in Lokoli for many purposes, among which food, packaging, alcoholic drinks, medicines, construction, etc. Among the listed NTFP, the products and by-products made from Raphia hookeri are the most important because they are important sources of revenue for the inhabitants of the area. The number of stems of Raphia used per year for palm wine production is 15.452 by the 320 inhabitants, including 148 gatherers, 81 transformers and 91 tradesmen. This provides to the inhabitants an income of about 28,000 to 159,000 FCFA per month and per inhabitant, without forgetting the other activities undertaken by these inhabitants. This results in a strong human pressure on the vegetation of the area which is therefore in urgent need of protection.<p>The vegetation of the Lokoli forest has important values which indicate its conservation concern. It shelters plant and animal species that are endemic and/or endangered or vulnerable according to the red list of the IUCN, such as: Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. The swamp forest of Lokoli is a refuge for all these species who find here their ecological niche. On the socio-economic level, the Lokoli forest provides to the inhabitants an income for their subsistence. The Lokoli forest in southern Benin is a forest with a high conservation value and it has the potential to become a “biosphere reserve”.\ / Doctorat en Sciences / info:eu-repo/semantics/nonPublished