Resource managers need to be able to quickly and accurately map aquatic plants in freshwater lakes and ponds for regulatory purposes, to monitor the health of native species and to monitor the spread of invasive species. Site surveys and transects are expensive and time consuming, and low resolution imagery is not detailed enough to map multiple, small lakes spread out over large areas. This study evaluated methods for mapping aquatic plants using high resolution Quickbird satellite imagery obtained in 2007 and 2008. The study area included nine lakes in northern Indiana chosen because they are used for recreation, have residential development along their shorelines, support a diverse wildlife population, and are susceptible to invasive species. An unsupervised classification was used to develop two levels of classification. The Level I classification divided the vegetation into detailed classes of emergent and submerged vegetation based on plant structure. In the Level II classification, these classes were combined into more general categories. Overall accuracy of the Level I classification was 68% for the 2007 imagery and 58% for the 2008 imagery. The overall accuracy of the Level II classification was higher for both the 2007 and 2008 imagery at 75% and 74%, respectively. Classes containing bulrushes were the least accurately mapped in the Level I classification. In the Level II classification, the least accurately mapped class was submerged vegetation. Water and man-made surfaces were mapped with the highest degree of accuracy in both classification schemes. Overhanging trees and shore vegetation contributed to classification error. Overall, results of this research suggest that high resolution imagery provides useful information for natural resource managers. It is most applicable to mapping general aquatic vegetation categories, such as submerged and emergent vegetation, and providing general estimates of plant coverage in lakes. Better methods for mapping individual species, species assemblages, and submerged vegetation constitute areas for further research. / Indiana University-Purdue University Indianapolis (IUPUI)

Made available in DSpace on 2016-06-02T19:29:41Z (GMT). No. of bitstreams: 1 3992.pdf: 1107503 bytes, checksum: 7c3e8c7b1f79eb3747f360b3ec8d02b4 (MD5) Previous issue date: 2011-03-01 / The Lagoa do Peixe National Park is an important conservation unity, aiming to protect the wetlands, one of the most endangered type of ecosystem in the world. In Southern Brazil around 90% of the wetlands were already lost. The protected ecosystems in the park are ernationally important for biodiversity conservation and it is the unique Ramsar site in Southern Brazil. The existence of areas invaded by Pinus eliotti and the artificial breaching of the lagoon sandbar are severe problems that can threaten the biodiversity in this preservation area. The goal of this study was to evaluate the diversity of aquatic macrophyte present in the park and test some ecological hypothesis about the community diversity of aquatic macrophyte in natural areas and areas under influence of the main problems of the park (pine invasion and the sandbar breaching). To answer this questions a survey was conducted in 32 wetlands situated inside the park between 2007 and 2009. We identified 176 aquatic macrophyte species in the palustrine wetlands of the park. The aquatic macrophyte richness and composition in coastal wetlands are directly related to the isolation degree of these wetlands in relation to the source wetland and other closer wetlands. The wetland area was not a significant factor for the spatial structure of the aquatic macrophyte community. Other determinant factors for the community were habitat diversity and hydroperiod. The influence of those environmental characteristics was different among the macrophyte groups defined as: hydrophytes, palustrine, and amphibious. The presence of pine resulted in a decrease in macrophyte richness, and the species composition in this area is, in a general way, a subset of the species found in natural wetlands. The artificial sandbar breaching did not affect the richness of aquatic macrophytes in the floodplain wetlands of Lagoa do Peixe. However, in this areas affected by the sandbar breaching, the community composition 4 was characterized by a pattern of continuous species replacement during the two-year study. These results provide important information for wetland management in the park. / O Parque Nacional da Lagoa do Peixe, o único sítio Ramsar no sul do Brasil, é uma importante Unidade de Conservação do sul do Brasil visando à proteção de áreas úmidas um dos tipos de ecossistemas mais ameaçados no mundo. No sul do Brasil, cerca de 90% das áreas úmidas já foram perdidas. A existência de áreas invadidas por Pinus elliottii e a abertura artificial da barra da Lagoa do Peixe são problemas graves que podem representar severos riscos à biodiversidade no parque. O objetivo desse estudo foi avaliar a diversidade de macrófitas aquáticas do parque e testar algumas hipóteses ecológicas sobre a dinâmica da comunidade de macrófitas aquáticas em áreas naturais e sob a influência da invasão do pinus e da abertura da barra. Foi realizado um inventário em 32 áreas úmidas do parque entre 2007 e 2009, nas quais foram identificadas 176 espécies de macrófitas aquáticas. A riqueza e a composição de macrófitas aquáticas estiveram diretamente relacionadas ao grau de isolamento dessas áreas em relação às áreas-fonte e a outras áreas úmidas próximas. O tamanho da área não foi um fator importante para a estrutura espacial da comunidade de macrófitas aquáticas, sendo fatores determinantes a diversidade de hábitats e o hidroperíodo. A influência desses fatores variou entre os grupos de macrófitas definidos como: hidrófitas, palustres e anfíbias. A invasão por pinus resultou na redução da riqueza de macrófitas e a composição de espécies nessas áreas é, de forma geral, um subconjunto das espécies encontradas nas áreas úmidas naturais. A abertura da barra não alterou a riqueza de macrófitas, as quais estão sujeitas ao manejo da barra. A composição da comunidade foi caracterizada por um padrão de contínua substituição de espécies ao longo dos dois anos de estudo. Esses resultados são informações importantes para o gerenciamento das áreas úmidas do parque.

The search for alternatives to the fossil oil and concern about environmental pollution has increasingly supported the importance of biofuels. The production of bio-oil from aquatic plants (water hyacinth) has become as interesting alternative due to its rapid growth rate, robust nature and unrelated to the food chain. The present work aimed to study the application of conventional and catalytic pyrolysis to convert aquatic plants like Eichhornia crassipes (EC) and Eichhornia azurea (EA) in bio-oil, employing Ferrierite and Y zeolite as catalysts. These plants were obtained in Aracaju-SE and Itabaiana-SE, respectively. The micropyrolys is were performed at three temperatures (400, 500 and 600 °C). The catalytic micropyrolysis using Ferrierite and Y zeolite was performed in the same condition applying 1 and 5% of catalysts w/w. The bio-oils solutions obtained were characterized by GC/MS and GC-FID. The micropyrolysis performed in the absence of catalyst showed similar chromatographic profiles to the biomasses tested, with the composition of bio-oils showing phenolic compounds, acids and alcohols. With Ferrierite as catalyst at 5% in the micropyrolysis and performing a study from the total area of the obtained chromatograms was observed the higher yield by GC-FID caused by the increased formation of small molecular mass compounds from biomasses. However, when used 1% of the same catalyst to EC was not observed a very significant difference in relation with no catalyst pyrolysis. To the EA in this condition was observed a significant yield reduction when performed at 500 °C. When used Y catalyst for EA pyrolysis a smaller yield was observed at all studied temperatures that shows a significantly inhibited formation of compounds derived from these lignocelullosic biomasses. However for the EC catalytic pyrolysis with 5% of Y catalyst at 500 °C we observed the largest decrease in the yield from the chromatograms area. The bio-oils characterization gave compounds identified belong to the following classes: alcohol, phenol, and sugar acids. The bio-oils from catalytic pyrolysis of EC and EA biomass showed a high content of phenolic compounds and acidic compounds. / A procura por soluções alternativas para a substituição total ou parcial do petróleo e a preocupação com a poluição ambiental tem reforçado cada vez mais a importância da produção de biocombustíveis. Neste sentido a produção de bio-óleo a partir de plantas aquáticas tornou-se uma alternativa interessante. Estas plantas são invasoras e possuem alta taxa de crescimento, natureza robusta e não tem relação com a cadeia alimentar. Neste trabalho, biomassas provenientes de plantas aquáticas, obtidas em Itabaiana-SE e Aracaju-SE, das espécies crassipes (EC) e azurea (EA), ambas do gênero Eichhornia, foram submetidas a micropirólise convencional a três temperaturas, 400, 500 e 600 ºC, e catalítica empregando catalisadores do tipo zeólita Ferrierita e Y nas proporções de 1 e 5%. As soluções de bio-óleos produzidas foram caracterizadas por CG/EM e CG-FID. Na micropirólise realizada na ausência de catalisador foi observado semelhança na composição química do bio-óleo para todas as condições testadas. Empregando 5% de catalisador Ferrierita na micropirólise, e realizando um estudo da área total dos cromatogramas obtidos foram observados aumentos significativos a 400 ºC para EC (+53,74%) e para a EA (+43,67%). A 1% deste mesmo catalisador para a EC houve diminuição da área total nas três temperaturas, enquanto que para EA houve diminuição na área total a 500 ºC (-48,09%). Quando empregado a zeólita Y nas duas proporções foi observado menor capacidade de produção de bio-óleo para EA em todas as temperaturas estudadas. A maior diminuição de área foi a 600 ºC (-25,70%) a 1% de catalisador e quando utilizado 5% foi a 500 ºC (-84,34%), ou seja, houve a inibição significativa na formação de bio-óleo. Para a EC foi observado a maior diminuição da capacidade de conversão térmica catalítica desta biomassa em bio-óleo na condição de 5% de zeólita Y, a 500 ºC (-33,23%) e na condição de 1% de zeólita Y, a 600 ºC (-46,77%). Os principais compostos identificados nos bio-óleos obtidos foram das classes do álcoois, fenóis, ácidos e açúcares. O bio-óleo obtido por pirólise catalítica das biomassas EC e EA apresentou um alto teor de compostos fenólicos e ácidos.

The Goukou Wetland is a 700 ha unchannelled valley bottom wetland near the town of Riversdale in the Western Cape of South Africa. The wetland is approximately 16 km long and between 200 and 800 m wide, with peat deposits up to 8 m deep that get progressively shallower downstream. The Goukou Wetland is one of the last remaining intact peatlands of significant size in the Western Cape. However, there is increasing human pressure on these peat wetlands, where the dominant plant is palmiet (Prionium serratum), which is endemic to the Western and Eastern Cape Provinces of South Africa. Palmiet is viewed as a problem plant by farmers as it is believed to block waterways and promote inundation of arable land and infrastructure. Many landowners therefore actively remove palmiet from peatlands, threatening the integrity of these wetlands. Although the hydrogeomorphic origin of large, non-peat floodplain and valley bottom wetlands has been investigated in South Africa, unchannelled valley-bottom wetlands with deep peat accumulations are rare features and have not been well studied. The hydrogeomorphic factors leading to peat accumulation have been documented elsewhere in Southern Africa, where aggradation due to sedimentation along trunk streams may block a tributary stream, elevating the local base level of the tributary, creating the accommodation space for organic sedimentation. Alternatively, sedimentation along a trunk stream at the toe of a tributary stream may similarly block a trunk stream, promoting organic sedimentation along the trunk stream upstream of the tributary. This pattern of peat accumulation is associated with declining peat thickness upstream of the blocked valley. In the case of the Goukou Wetland, however, peat depth and organic content was found to increase consistently upstream from the toe to the head of the wetland. The Goukou Wetland was graded along its length, with gradient increasing consistently upstream in response to longitudinal variation in discharge. There was no clear relationship between peat formation and tributary streams blocking the wetland. Instead, the distribution of peat and the extent of the wetland appeared to be controlled by the plant palmiet, whose clonal nature and robust root, rhizome and stem system allowed it to grow from channel banks and islands into fast-flowing river channels, slowing river flows and ultimately blocking the channel. The promotion of diffuse flows within the dense, monospecific stands of palmiet creates conditions conducive to water retention and peat accumulation. By growing across the full width of the valley floor, the plant is able to constrict the stream, trapping sediment and slowing flows such that the fluvial environment is changed from a fast flowing stream to one with slow, diffuse flow. These processes appear to lead to the formation of organic sediment, accumulating to form a deep peat basin. The sustained input of water from the folded and fractured quartzite lithologies of the Cape Supergroup that make up the Langeberg Mountains, which provide the bulk of the water supply to the wetland, is also important in promoting permanent flooding in the wetland. A feature that characterized the wetland was the fact that bedrock across the valley beneath the peat deposits exhibited a remarkably uniform elevation. This suggests that over long periods of time (tens to hundreds of thousands of years), bedrock has been laterally planed across the valley floor. It is proposed that valley widening associated with lateral planning of Uitenhage Formation rocks has taken place during periods of episodic very high flows. During these episodes, erosion cuts into the peat wetland and valley sides, cutting to bedrock and planing the valley floor to a uniform elevation for a given distance from the head of the wetland. Periods of episodic degradation are followed by periods of renewed peat accumulation associated with palmiet establishment, such that the wetland valley is shaped by repeated cycles of cutting and filling. Palmiet can be considered an “ecosystem engineer” that is integral to the formation of these deep peat basins. Removal of palmiet from these systems is likely to have negative consequences for the wetland and its functions in that water storage will be reduced, erosion will increase dramatically, and the water-purification function of the wetlands will be lost. Management of these wetlands, which are close to the geomorphic threshold slopes for their size, is therefore essential if they are to be preserved for the benefit of human well-being.

Indiana University-Purdue University Indianapolis (IUPUI) / Resource managers need to be able to quickly and accurately map aquatic plants in freshwater lakes and ponds for regulatory purposes, to monitor the health of native species and to monitor the spread of invasive species. Site surveys and transects are expensive and time consuming, and low resolution imagery is not detailed enough to map multiple, small lakes spread out over large areas. This study evaluated methods for mapping aquatic plants using high resolution Quickbird satellite imagery obtained in 2007 and 2008. The study area included nine lakes in northern Indiana chosen because they are used for recreation, have residential development along their shorelines, support a diverse wildlife population, and are susceptible to invasive species. An unsupervised classification was used to develop two levels of classification. The Level I classification divided the vegetation into detailed classes of emergent and submerged vegetation based on plant structure. In the Level II classification, these classes were combined into more general categories. Overall accuracy of the Level I classification was 68% for the 2007 imagery and 58% for the 2008 imagery. The overall accuracy of the Level II classification was higher for both the 2007 and 2008 imagery at 75% and 74%, respectively. Classes containing bulrushes were the least accurately mapped in the Level I classification. In the Level II classification, the least accurately mapped class was submerged vegetation. Water and man-made surfaces were mapped with the highest degree of accuracy in both classification schemes. Overhanging trees and shore vegetation contributed to classification error. Overall, results of this research suggest that high resolution imagery provides useful information for natural resource managers. It is most applicable to mapping general aquatic vegetation categories, such as submerged and emergent vegetation, and providing general estimates of plant coverage in lakes. Better methods for mapping individual species, species assemblages, and submerged vegetation constitute areas for further research.

No description available.

Multiple dimensions of biodiversity within and across producer and consumer guilds in the food web affect an ecosystem’s functionality and stability. Tropical and subtropical aquatic ecosystems, which are extremely diverse, have received much less attention than terrestrial ecosystems in regards to the effects of biodiversity on ecosystem functioning. We conducted a field experiment that tested for effects of macrophyte functional diversity on diversity and stability of associated fish assemblages in floodplain lakes of the Upper Paraná River floodplain, Brazil. Three levels of macrophyte functional diversity were maintained through time in five floodplain lakes and response variables included various components of fish taxonomic and functional diversity and stability. Components of functional diversity of fish assemblages were quantified using a suite of ecomorphological traits that relate to foraging and habitat use. Response variables primarily distinguished macrophyte treatments from the control. Macrophyte treatments had, on average, double the number of species and total abundance than the control treatment, but only limited effects on stability. The high diversity treatment was essentially nested within the low diversity for assemblage structure and had similar or even slightly lower levels of species richness and abundance in most cases. Gymnotiformes and young-of-year were diverse and relatively abundant in macrophyte treatments contributing to the large differences in diversity between macrophyte and control treatments. Higher fish diversity in structured habitats compared to more homogenous habitats is likely associated with increased ecomorphological diversity to exploit heterogeneous microhabitats and resources provided by the macrophytes.

Zur Sicherung der Fischbestände muss die Aquakultur ihren Beitrag zur Weltfischversorgung weiter steigern. Solange jedoch die Fischfutter Produktion stark von der Gewinnung von Fischmehl abhängig ist, bestehen für die Aquakultur natürliche Begrenzungen und die Gefahr der Überfischung der Fischbestände bleibt erhalten. Wenn das Wachstumspotenzial der Aquakultur ausgeschöpft werden soll, müssen beträchtliche Mengen von Nährstoffeinträgen in Form von vollständigen Aquakultur-Mischfuttermitteln auf einer nachhaltigen Basis verfügbar sein. Aufgrund des gestiegenen Preises von kommerziellem Fischfutter sind Kleinproduzenten nicht in der Lage dieses zu erwerben. Daher ist es notwendig, ihnen alternatives Fischfutter zur Verfügung zu stellen. Wasserpflanzen können eine bedeutende Nahrungsquelle für herbivore- und omnivore Fische sein. Dennoch ist die Nutzung dieser Pflanzen als Zusatz für Fischfutter durch eine Reihe antinutritiver Substanzen, welche das normale Fischwachstum negativ beeinträchtigen, begrenzt. Unterschiedliche Behandlungen der Pflanzen können den Anteil an antinutritiven Substanzen reduzieren. Das Ziel dieser Dissertation war es, das nutritive Potential von Wasserpflanzen zu bestimmen. Die Wirkung der Behandlungen wie Sonnentrocknung oder Fermentierung zu bewerten und den Effekt ihrer Nutzung als Fischfutter auf das Wachstum von kultivierten Fischen zu erfassen. Dazu wurden Rationen mit einem geringen Gehalt an Fischmehl (3%) und bis zu 25% der Wasserpflanzen an die Fischspezies P. brachypomus und O. niloticus verfüttert. Die Ergebnisse der Untersuchung zeigen dass, eine ausschließlich auf aquatischen Makrophyten basierende Fütterung nicht empfehlenswert ist. Indem sie jedoch mit anderen lokal verfügbaren Agrar-Nebenerzeugnissen oder sogar mit kommerziellen Futtermitteln kombiniert werden, könnten die Futterkosten erheblich reduziert werden und bäuerlichen Kleinbetrieben eine Möglichkeit zum Wettbewerb auf den lokalen Märkten eröffnen. / It is commonly known that aquaculture needs to increase further its net contribution to the total world fish supplies. However, at present almost all farming operations, based on the use of fish feed, are highly dependent on available fishery resources for the production of fish meal, becoming a reducing activity rather than an activity suppling fishery resources. If the aquaculture growth potential is to be maintained, then considerable quantities of nutrient inputs in the form of aquafeeds will have to be available on a sustainable basis. On a long-term the small producers will be unable to depend on commercial aquafeeds based traditionally on fish meal, due to its increased price. Small-scale farmers need an alternative fish feed wherever possible based on the use of non-food grade locally feed resources, which is available in rural areas, is low-cost and is suitable for the proper growth and maintenance of native fish. Aquatic plants are considered important nutritional sources for herbivorous-omnivorous fish. However, the use of plant-derived materials as fish feed ingredient is limited by the presence of wide variety of antinutrients that affect the normal fish growth negatively; so that plants should be processed to reduce the effects of these compounds. Considering these aspects, this study assessed the nutritional potential of aquatic plants available in rural Colombia treated by sun drying and by fermentation and the effect of their use as fish feed on the growth performance of common cultured tropical fish (Piaractus brachypomus and Oreochromis niloticus) fed low fishmeal diets (3%) and until 25% of aquatic plants. The results of this study showed that a feeding exclusively based on aquatic plants is not recommendable; but to combine them with other locally available by-products of agriculture or even with commercial diets might considerably reduce feeding cost and provide to the small-scale farmers the opportunity to compete in local markets.