Nutrient availability, water depth, competition, and soil management effects on cattail (Typha latifolia) growth in wetland systems were examined. Soluble reactive phosphorous (SRP), nitrate-nitrogen (NO3-N), and ammonia-nitrogen (NH3-N) removals were tested at a constructed wetland receiving municipal wastewater effluent. Over all, no significant differences in nutrients occurred between diverse planted and cattail areas. T. latifolia seeds, under the canopy of Eleochoris macrostachya, had low seed germination. Established stands of emergent vegetation can prevent cattail colonization and spread. Germination of T. latifolia at various water depths was tested, and depth impacts on cattail seedling growth and survival were ascertained using various moist soil management techniques in three ponds. Water levels at 0cm and >40cm can adversely impact cattail establishment.

Emergent macrophytes are an integral part of prairie marshes and involved in many of the services that make these ecosystems valuable. Water depth and hydroperiod are two environmental variables that can influence the growth and nutrient content of emergent macrophytes. This study looked at the growth and nutrient content response of hybrid cattail (Typha x glauca) to water depth and hydroperiod in two prairie marshes in southern Manitoba, Canada. Above- and belowground samples of hybrid cattails were collected along a water depth gradient at Oak Hammock Marsh, Canada, and analyzed for biomass, total phosphorus, total nitrogen, total Kjeldahl nitrogen content, shoot height, and density. A second dataset was obtained from the Marsh Ecology Research Program (MERP) experiment, and used to determine the biomass and nutrient content response of the hybrid cattail following one or two years of drawdown. / October 2015

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels. In addition, I used a multivariate PCA analysis to evaluate all parameters together. The water depth was significantly larger in habitats with mussels than in those without. Shading varied from 5 to 80 %, but there was no significant difference between habitats with and without mussels. There was no correlation between water depth and mussel density and not between shading and mussel density either. The multivariate PCA analysis showed that the habitats with and without mussels were different from with regard to the PC1 axis, which included water depth, bottom substrate and water velocity. Alone, the water depth is not enough to predict the presence of Unio crassus in the stream, and it is likely that more parameters need to be considered.  Previous work indicate that the more parameters and habitats that are investigated, the more confident results can be stated of which habitats Unio crassus prefer.

The passage of two major hurricanes across southwest Florida (Category 5, Labor Day Hurricane of 1935; Category 4, Hurricane Donna 1960) resulted in fragmentation of mangrove forest at Big Sable Creek, Everglades National Park. Over time forest fragmentation led to forest loss and patchy conversion to unvegetated mudflats. My goal was to determine the consequence of forest fragmentation on nekton (i.e., fish and decapod crustaceans) inhabiting the intertidal zone. I used block nets across intertidal rivulets to compare nekton leaving replicate forest and unvegetated mudflat sites from October, 2002 through April 2004. Overall nekton density (individuals per 100 m3) was significantly greater (rmANOVA, p < 0.001) for mangrove (212·100 m-3) than mudflat (26·100 m-3) habitats. Biomass (g per 100 m3) was also significantly greater for mangrove (715 g·100 m-3) than mudflat (20 g·100 m-3) habitats. Composition of the nekton assemblage also differed between habitat types (ANOSIM global R=0.416, p<0.001). Structure-associated species dominated forested sites, whereas schooling species dominated mudflats. When mangrove destruction and mortality results in fragmentation (Craighead and Gilbert, 1962; Smith et al., 1994; Wanless et al., 1994), nekton density and biomass will likely decline as a consequence.

Gerard De Geer was the first one to identify De Geer-moraines, and has since then been mapped by many other studies around the world.  The focus of this study was to examine the environment the ridges form in, regarding the water depth during creation, the importance of topography and the melting rate of the ice. Using airborne Light Detection and Ranging  (LiDAR) data, De Geer- moraines were mapped around eastern Norrbotten county, including Piteå, Boden and Luleå. A total of 14 651 De Geer-moraines were identified over the selected area. Six parameters were analysed during this study; length, orientation, steepness, distance between ridges, current ground level and depth below highest shoreline. In some areas, ridges showed a high, local steepness, while other study sites showed ridges with a varied interconnected form, from straight, to convex and concave. Prominent De Geer-moraines had been identified, where the mean distance between the ridges was calculated to 345 m. Furthermore, other glacial formations (drumlins, flutings, rogen moraines and eskers) showed a relationship to De Geer-moraines, either with a similar angle or a perpendicular relation. A great water depth showed a significant role in the creation of the ridges, with 75% of the identified De Geer-moraines formed in a water depth greater than 150 m. De Geer- moraines found on topographic lows tend to have an interconnected concave form, while over or close to elevated areas; they’re slightly convex. The mean distance between prominent ridges showed a connection to the average retreat rate of the last ice, which suggests that prominent ridges had been formed annually.

The increasing demand for and limited supply of fresh water necessitates an understanding of how human actions affect aquatic ecosystems. Anthropogenic impacts to these ecosystems occur in many forms including eutrophication, invasive species removals, and hydrologic alterations. Ground water extraction is one such action that can dramatically impact wetland hydrology and is increasing in occurrence globally as clean surface water resources are exhausted. Despite the importance of ground water extraction to meet human demand, little information is available concerning the response of vegetation communities to chronic ground water extraction. Over extraction is known to result in reduced water levels and duration, resulting in a shift towards more upland tolerant species; however, detailed information concerning the response of the individual species comprising these communities and how wetlands shift along with pumping regime remains unavailable. The following dissertation combines historical hydrology and ground cover vegetation data with recent monitoring to describe how ground cover (herbaceous species) and canopy (tree species) vegetation respond to fluctuations in hydrology and ground water extraction. Ground cover communities were extremely diverse with a total of 103 species being sampled in the historical ground cover vegetation dataset. Juncus repens was the most widely distributed species and was observed in 36% of all samples. The 29 species most widely observed in the ground cover strata (height) displayed relatively narrow ranges of preferred water depth and duration with Amphicarpum muhlenbergianum being found in the driest areas and Pontederia cordata and Ludwigia repens the wettest. In general species found in shallower water depths also tended to be found in locations with shorter hydroperiods, although woody species tended to found in areas with relatively shallow water depths with extended hydroperiod. Ground cover vegetation is extremely useful as an indicator of recent hydrology, although the hydrologic preference of the species in the current study does not reflect the assumed ecology of the species utilized by Florida Administrative Code 62-340.450. Additional research to validate and improve the accuracy of this classification system is required. When ground water extraction volumes in well fields was significantly reduced, ground cover communities were responsive, as was indicated by Permanova results (Before After Control Impact). All ground cover at wetlands located within well fields became more indicative of wetter conditions while control wetlands responding only to climate and weather all became drier. In contrast, several well fields displayed reductions in water levels and hydroperiod following extraction reductions. The shift in ground cover community indicates that ground water extraction has not produced an alternative stable state and restoration of these ecosystems is possible through alterations in ground water extraction volumes alone. As ground water extraction volumes were increased, tree communities responded by displaying increased occurrance of non-Taxodium sp. trees, mortality of wetland tree species, and light availability. All wetlands remained dominated by mature Taxodium sp. regardless of the amount of ground water impact indicating that each wetland has not yet shifted into a new community type as a result of non-Taxodium tree encroachment; however, recruitment and mortality patterns of both Taxodium and non-Taxodium species indicate this may occur in the future. Changes in light availability at the wetland floor associated with tree species is likely providing an additional feedback mechanism on ground cover communities. Results from this dissertation indicate that vegetation communities are extremely responsive to changes in hydrology and have shown significant changes associated with ground water extraction. These changes may not be permanent; however, and alterations in extraction volumes and timing can provide changes in vegetation communities even after decades. Routine long term monitoring should be conducted, in addition to critical assessments of current extraction volumes, to assess the current status of vegetation ecosystems and allow for individuals to best manage aquatic resources for all uses.

Made available in DSpace on 2016-01-26T18:56:34Z (GMT). No. of bitstreams: 1 dissertacao completa.pdf: 364191 bytes, checksum: d74c3583ae69ea3e267b2f257654a08b (MD5) Previous issue date: 2007-12-21 / The growing demand for forest products has led Brazilian reflorestation companies that work out reforestation with Eucalyptus to a search for higher productivity due to their use for cellulose, paper and chancoal. One of the most limiting factors for agricultural production is the water deficit, which inhibits several physiological process in plants. This work was aimed to study the effects of water deficit on the physiology of seedlings of four species Eucalyptus: E. citriodora, E. pellita, E. urograndis e E. grandis, looking for information about plants susceptibility at water deficit in the initial phase their of development with is a critical period for the installation of forest. The seedlings were exposed to three irrigation schemes, based on class A evaporation pan with replacement of 100, 50 and 25% of the water level, which were evaluated by gas exchange, chlorophyll fluorescence and content leaf water potential. It was observed that E. pellita and E.citrodora were more tolerant to level water imposed by the regime of 50% of replacement of the water depth. Meanwhile the regime with 25% effected the species so similar / A crescente demanda de produtos florestais tem levado as empresas brasileiras que realizam reflorestamento com espécies do gênero Eucalyptus a uma busca por maior produtividade devido a sua utilização para celulose, papel e carvão. Um dos principais fatores limitante da produção agrícola é falta de água, que inibe vários processos fisiológicos nas plantas. Este trabalho teve por objetivo estudar os efeitos da deficiência hídrica sobre a fisiologia de plântulas de quatro espécies de Eucalyptus: E. citriodora, E. pellita, E. urograndis e E. grandis, visando obter informações sobre a susceptibilidade das plantas ao déficit hídrico na fase inicial de seu desenvolvimento que é um período crítico para a implantação de povoamentos florestais. As plântulas foram expostas a três regimes de irrigação, baseados na evaporação de um mini-tanque classe A com reposição de 100, 50 e 25 % da lâmina de água, das quais foram avaliadas em relação as trocas gasosas, fluorescência da clorofila a, conteúdo de clorofila e potencial de água foliar. Observou-se que as espécies de E.pellita e E. citriodora foram as mais tolerantes ao défict hídrico imposto pelo regime de 50% de reposição da lâmina de água. Entretanto o regime com 25% afetou as espécies de forma similar

Made available in DSpace on 2016-07-18T17:51:15Z (GMT). No. of bitstreams: 1 dissertacao completa.pdf: 364191 bytes, checksum: d74c3583ae69ea3e267b2f257654a08b (MD5) Previous issue date: 2007-12-21 / The growing demand for forest products has led Brazilian reflorestation companies that work out reforestation with Eucalyptus to a search for higher productivity due to their use for cellulose, paper and chancoal. One of the most limiting factors for agricultural production is the water deficit, which inhibits several physiological process in plants. This work was aimed to study the effects of water deficit on the physiology of seedlings of four species Eucalyptus: E. citriodora, E. pellita, E. urograndis e E. grandis, looking for information about plants susceptibility at water deficit in the initial phase their of development with is a critical period for the installation of forest. The seedlings were exposed to three irrigation schemes, based on class A evaporation pan with replacement of 100, 50 and 25% of the water level, which were evaluated by gas exchange, chlorophyll fluorescence and content leaf water potential. It was observed that E. pellita and E.citrodora were more tolerant to level water imposed by the regime of 50% of replacement of the water depth. Meanwhile the regime with 25% effected the species so similar / A crescente demanda de produtos florestais tem levado as empresas brasileiras que realizam reflorestamento com espécies do gênero Eucalyptus a uma busca por maior produtividade devido a sua utilização para celulose, papel e carvão. Um dos principais fatores limitante da produção agrícola é falta de água, que inibe vários processos fisiológicos nas plantas. Este trabalho teve por objetivo estudar os efeitos da deficiência hídrica sobre a fisiologia de plântulas de quatro espécies de Eucalyptus: E. citriodora, E. pellita, E. urograndis e E. grandis, visando obter informações sobre a susceptibilidade das plantas ao déficit hídrico na fase inicial de seu desenvolvimento que é um período crítico para a implantação de povoamentos florestais. As plântulas foram expostas a três regimes de irrigação, baseados na evaporação de um mini-tanque classe A com reposição de 100, 50 e 25 % da lâmina de água, das quais foram avaliadas em relação as trocas gasosas, fluorescência da clorofila a, conteúdo de clorofila e potencial de água foliar. Observou-se que as espécies de E.pellita e E. citriodora foram as mais tolerantes ao défict hídrico imposto pelo regime de 50% de reposição da lâmina de água. Entretanto o regime com 25% afetou as espécies de forma similar

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京都大学 / 新制・課程博士 / 博士(理学) / 甲第24423号 / 理博第4922号 / 新制||理||1703(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 伊藤 喜宏, 准教授 西村 卓也, 教授 王 功輝 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM