The study was performed on 24 localities throughout Socotra Island to approach the threatened tree species of Dendrosicyos socotrana (DS, Cucumber tree), its population and regeneration. 14 localities out of these localities contain DS individuals. This survey studied the land-cover classes of High Shrubland with Succulents, Low Croton-Jatropha Shrubland, Sparse Dwarf Shrubland, Wadies, Submontane Grassland, Submontane Shrubland, Frankincense Woodland, Dracaena Woodland, Urban land, Date Palm Plantation, and Frankincense Forest. Studied localities form an area of 96 square kilometres and 204 individuals have been found (excluding seedlings). The basic measurement of specimens had been taken (height, GBH, fertility and coordinates) as well as collected data about biotope site and regeneration. Regeneration occurred approximately on 36 % of all localities. Dendrosicyos socotrana could be fertile on height of 2 m. The estimation of total number of DS population on Socotra Island could be 8 113 individuals. It is conspicuously showing that High Shrubland with Succulents and Wadies are the best habitat for Dendrosicyos socotrana, the reason is that the northern-slopes and wadies protect Dendrosicyos socotrana from the strong monsoon wind in the Island. As for others land-cover, DS species prefers wind-protected locations. In conclusion the DS population are decreasing in whole Island and I am suggesting to seek for a solution for this unique species.

This masters thesis deals with the longterm changes of forest and nonforest woody vegetation in the area of the former Děčín estate. For my analysis I have used the avalaible historical maps and modern ortophotographs, which I have processed using the ArcGIS software. While many places of the Earth are going through deforesation, on the other hand in Europe there is a significant rise in the area covered by woodlands. I have come to the same results in my thesis, in which at the studied site, in which there was an expansion of forest woody vegetation between the years 1953 and 2015. While when comparing the map of The Stabile cadaster and an aerial image from 1953 there was a decrease of forest woody vegetation. These results pary correlate with the demographic development of the Děčín district as well as general political and economic development of the area in the analyzed time period. The results are compared to similar avalaible studies, on the base of which it seems that the resukts of this study are not a unique trend.

This diploma thesis follows up the influence of horizontal and vertical structure of biotopes on biodiversity of bird species of Czech Republic of forest and open sites. Vertical structure model was created from digital model of surface of Czech Republic (1st generation) and digital model of relief of Czech Republic (5th generation). Information about horizontal structure were derived by analyzing aerial imagery. Then single variables were detected from these data. Subsequently, it was analyzed which of these variables and which way influence bird diversity. On both types of sites was found increasing bird diversity with increasing diversity of vertical structure. With increasing horizontal structure, however, bird diversity significantly increased only on open sites. The influence of other characteristics was mostly different on bird diversity of open and forest sites, but, for both types of sites, the positive influence had for example edge density of land cover categories or edge density of height categories. Additional part of this thesis was to explore if vertical characteristics of biotopes could influence prediction of selected bird species. Results was different in forest and open biotopes, nevertheless in both types of sites was found potential use of both horizontal and vertical variables.

The aim of this thesis is to evaluate whether connectivity indices are usable for bird prediction. The study area contains of the whole country but is divided into separate squares with area of 133 km 2 each, where the presence or absence of the bird species is known. The dependence is tested on landscape connectivity indices presented by prof. S. Saura. The land cover contains of Corine land cover 2012 data. The results will be evaluated with logistic regression approach on sample data including 4 different dispersal distances (500 m, 1 000 m, 2 000 m and 3 000 m) and 10 specific bird species typical for given land cover. The corelation between land cover area presence of the bird is also tested.

A durabilidade de estruturas de concreto armado é altamente dependente das características do concreto de cobrimento das armaduras e sua espessura. O fracasso na obtenção do cobrimento é o fator de maior influência na corrosão prematura de armaduras que, por sua vez, é a principal forma de deterioração de estruturas de concreto armado. Pesquisas indicam que o cobrimento mínimo normatizado não tem sido alcançado em sua totalidade nas atuais obras que adotam esta solução estrutural, tratando-se de um problema crônico e não esporádico. Esta situação foi constatada através de um levantamento realizado in loco do cobrimento obtido em obras de Porto Alegre/RS e Cuiabá/MT. Dentre os elementos estruturais mais prejudicados, encontram-se as lajes e o fundo das vigas que, em determinadas ocasiões, apresentaram a totalidade dos valores medidos de cobrimento abaixo do valor mínimo especificado em norma. Uma das causas observadas para falha na obtenção do cobrimento mínimo normatizado é o uso incorreto de espaçadores e a utilização de espaçadores inadequados, bem como a falta de uma norma brasileira que regulamente o produto e seu uso e, consequentemente, a falta de certificação de qualidade pelo órgão responsável. Tendo este trabalho como foco o espaçador propriamente dito, foram propostos requisitos e critérios de desempenho para os espaçadores, assim como métodos para avaliação dos mesmos. A maioria dos requisitos e critérios propostos foram compilados e adaptados a partir de normas internacionais. Depois de estabelecidos os requisitos, critérios e métodos de avaliação, alguns espaçadores plásticos disponíveis no mercado foram efetivamente testados segundo a metodologia proposta. Nenhum modelo de espaçador avaliado provou-se satisfatório segundo a abordagem de desempenho estabelecida. Entretanto, ficou claro que os requisitos, critérios e métodos de avaliação propostos são adequados para avaliação de desempenho de espaçadores plásticos. Diante da diversidade de modelos e de desempenho dos espaçadores ofertados, ficou comprovada a necessidade de uma norma brasileira regulamentadora para este produto, a fim de balizar a qualidade dos espaçadores disponíveis no mercado e eliminar esta variável das causas da não obtenção do correto cobrimento. Desta forma, este trabalho visa colaborar com melhorias na questão da durabilidade de estruturas de concreto armado com foco na obtenção da correta espessura de cobrimento. / The reinforced concrete structures durability is highly dependent on the concrete cover to reinforcement characteristics and its thickness. The failure on achieving the specified cover thickness is the most influential factor in premature reinforcement corrosion, which is the main deterioration form of reinforced concrete structures. Researches indicate that the minimum standardized cover has not been completely achieved in current constructions that adopt this structural solution, which is a chronic problem and not sporadic. This situation was reaffirmed through a survey conducted in loco of the cover obtained in Porto Alegre/RS and Cuiabá/MT constructions. Among the most damaged structural elements are the slabs and beams bottom that, sometimes, showed one hundred percent probability of unsatisfactory standard cover levels. One of the failure causes observed to obtain the minimum standardized cover is the incorrect use of spacers and the use of inappropriate spacers, not to mention the lack of a Brazilian standard for regulating its manufacturing and, therefore, the lack of quality certification by the responsible agency. Having this work focused on the spacers themselves, requirements and performance criteria for the spacers, as well as methods for their evaluation, were proposed. Most of them were compiled and adapted from international standards. After established the requirements, criteria and evaluation methods, some plastic spacers available in the market were effectively tested according to the proposed methodology. No model spacers evaluated proved to be satisfactory according to the established performance approach. However, it was clear that any requirements, criteria and set evaluation methods can be satisfied. Given the diversity of spacers models and offered performances, it has been stated the need for a Brazilian regulatory standard for this product, in order to gauge the quality of the ones commercially available and to eliminate this variable among the causes of failure in obtaining the correct cover. Thus, this work aims to collaborate with improvements on the durability issue of reinforced concrete structures with a focus on getting the right cover thickness.

AN ABSTRACT OF THE THESIS OF Taylor J. Sievers, for the Master of Science degree in Plant, Soil, and Agricultural Systems, presented on May 13, 2016, at Southern Illinois University Carbondale. TITLE: COVER CROP CHARACTERISITICS AND IMPACTS ON AGRONOMIC SYSTEMS IN SOUTHERN ILLINOIS MAJOR PROFESSOR: Dr. Rachel L. Cook Midwestern farmers face the dual challenge of increasing crop production while reducing environmental impacts. Best management practices to decrease nutrient and soil loss in agronomic systems has fueled the resurgence of the cover cropping practice, but many growers are uncertain about the effects that different cover crop species may have in their fields or how combinations of tillage and cover crops may influence yields or soil characteristics. Different cover crop characteristics, such as above and belowground biomass production, nitrogen content, and decomposition may affect both soils and crop yields. Field experiments were conducted across two sites in southern Illinois from 2013 to 2015 to study characteristics of cover crops and the impact of cover crops and tillage on soils, nutrient availability, and agronomic field crop performance. Specifically, these studies 1) determine the effects of cover crops on soil nitrogen, 2) quantify above and belowground biomass production of cover crops, 3) quantify the grain yield and belowground biomass of the following crops of corn (Zea mays L.) and soybeans (Glycine max L. Merr.), and 4) evaluate cover crop decomposition and nutrient release of a leguminous and non-leguminous species. In both field sites, Hairy vetch (Vicia villosa Roth) treatments produced the most biomass and accumulated the most nitrogen of all cover crop treatments. Cover crop establishment was a problem for the 2014−2015 field season. Cover crops, for the most part, did not have an influence on corn or soybean grain yields, except that corn following Hairy vetch treatments tended to be higher in grain yields than corn following Annual ryegrass treatments. Soybeans following Annual ryegrass treatments tended to be higher in grain yield than soybeans following Canola treatments. Root biomass production was higher for cover cropped plots than non-cover cropped plots (weed root biomass), and corn or soybean root biomass was more affected by tillage practices rather than the main effect of cover crop. Tilled treatments were typically higher in soil nitrate and total inorganic nitrogen compared to No-till treatments, and Annual ryegrass treatments were consistently lower in soil nitrogen compared to other cover crop treatments. Hairy vetch and cereal rye (Secale cereale L.) decomposition and nutrient release was monitored over a 16 week period, with litterbag and intact root core collections at 2, 4, 6, 8, 12, and 16 weeks. Decomposition and nitrogen release data were fit to a single exponential decay model with an asymptote. Cereal rye aboveground (k = 0.14) and belowground (k = 0.19) biomass decomposed more gradually compared to hairy vetch aboveground (k = 0.45) and belowground (k = 0.68) biomass. The same trend developed for nitrogen release with cereal rye aboveground (k = 0.07) and belowground (k = 0.19) biomass releasing nitrogen slower and more gradually compared to hairy vetch aboveground (k = 0.61) and belowground (k = 0.61) biomass. Most of the hairy vetch nitrogen was released around Week 2, but the corn crop did not reach the V6 growth stage until Week 8, therefore cover crop nitrogen release and cash crop uptake may have not been synchronized. Plant Root Simulator™ ion exchange resin membrane probes also captured significantly more nitrogen in hairy vetch plots compared to cereal rye plots at weeks 2, 4, 6, 8, and 12, which indicates that hairy vetch could increase the readily plant available total nitrogen (nitrate + ammonium) in the soil throughout the bulk of cover crop decomposition. Farmers should decrease the time between cover crop termination and cash crop planting in order to increase the likelihood of crop synchrony. This research will help farmers develop better management practices regarding inclusion of cover crops into traditional agronomic production systems.

The latest spillway in Bergeforsen was finished in 2014. It has a 25 metres wide spillway opening capable of discharging 1500 m^3/s at full reservoir retention level. The overflow chute ends in a 35 metres wide and 100 metres long stilling basin which then converges into 25 metres wide curved tunnel leading the water flow under a railway and back into the river. During the winter, the water in the stilling basin and the tunnel freezes, creating an ice cover all the way through the channel and limiting the water passage in the tunnel. For thinner ice covers, the channel can be flushed by discharging water into the spillway, but there are concerns that a colder winter might result in a ice cover of significant thickness, not prone to cracking at water discharges. This could result in water masses flowing on top of the ice cover into an ice covered tunnel leaving it at risk of being pressurized, posing some serious safety threats to the tunnel. This report presents a full-scale 3D model of the spillway with an ice cover as well as both transient and steady-state simulation results for several discharges to examine the effect of an impenetrable ice cover in the channel. The model is verified using American Society of Mechanical Engineers policy complete with an grid convergence index study. It was found that there was no risk for pressurized flow in the tunnel. However, serious wave-run ups was observed at the tunnel entrance and in the tunnel. / <p>Slutrapporten i projektkursen F7042T (15 hp) på civilingenjörsprogrammet i Teknisk fysik och elektroteknik (INTE EXJOBB).</p>

Ecosystem services are the benefits people obtain from ecosystems. Quantifying these benefits and understanding how they may change under multiple future pressures, such as climate change or land use change, is a highly uncertain exercise. In managing ecosystems to be resilient to future changes, natural resource managers need the most accurate information available, but also need to be informed of when and where they can be confident, or not, in projections of change. In this thesis, I address many of the key aspects of uncertainty in projections of change in ecosystem services, with a particular focus on challenges in West Africa. I show where and for what variables climate models may be reliably used in ecological studies, providing important advice for interpreting the impacts of climate change on biodiversity. Furthermore, I show that uncertainty in climate observations can also have a significant impact on climate change adaptation decisions at both the species level and in terms of protected area management. I also address how vegetation in West Africa may respond to future climate change. I found that even after uncertainties in climate and land use were considered, carbon storage in West African tropical forests was projected to increase where forest degradation remained low or reduced; vegetation productivity was projected to increase in all parts of West Africa, with the exception of locations in the West Sahel where the largest reductions in precipitation were projected; and, importantly for protected areas, ecosystems were projected to shift northwards despite uncertainty in precipitation projections. I also show the sensitivity of 3 major land surface models to uncertainty in vegetation mapping, thereby providing guidance to the remote sensing community on priorities to improve land cover mapping and to the earth system modelling community on bounds of uncertainty in carbon, moisture and energy budgets due to vegetation mapping uncertainties. Lastly, in using the latest land-atmosphere coupled convection-resolving model, I show that it is possible to simulate the observed interaction between landscape heterogeneity and local and regional scale precipitation in West Africa. This provides a timely and relevant tool that will allow scientists and natural resource managers to more accurately assess the impact of changes in land use on the regional climate of West Africa.

Made available in DSpace on 2016-03-07T19:20:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-08. Added 1 bitstream(s) on 2016-03-07T19:24:01Z : No. of bitstreams: 1 000859313.pdf: 21076207 bytes, checksum: a9c6ff7a00a20dda6fe0ac75d76184c4 (MD5) / O planejamento da sucessão de culturas aliada a cultivos de plantas de cobertura na entressafra e a descompactação mecânica são opções para minimizar a compactação na camada superficial do solo bem como proporcionar melhorias nos atributos do solo em sistema plantio direto (SPD), contribuindo para a sustentabilidade do sistema de produção. Assim, objetivou-se quantificar o efeito da descompactação mecânica do solo, no desenvolvimento e produtividade das plantas de cobertura na primavera em SPD, e também no crescimento e produtividade das culturas do arroz de terras altas e feijão de inverno em sucessão, além das alterações nos atributos químicos e físicos do solo, após cada cultivo das culturas anuais. O trabalho foi desenvolvido em Selvíria, MS em 2012/13 e 2013/14, em um Latossolo Vermelho de Cerrado, textura argilosa, com delineamento em blocos casualizados disposto em esquema fatorial 5x2 para o arroz e o feijão, com quatro repetições. Os tratamentos foram constituídos pela combinação de cinco plantas de cobertura (pousio (controle), Cajanus cajan, Crotalaria juncea, Urochloa ruziziensis e Pennisetum glaucum) com e sem escarificação mecânica do solo. A espécie de Pennisetum glaucum, independente do solo escarificado em SPD promoveu maior produtividade de matéria seca e acumulo de macronutrientes na parte aérea bem como maior persistência de resíduos vegetais; o solo escarificado em SPD e o cultivo anterior de Cajanus cajan proporcionaram maiores produtividades do arroz, no primeiro ano, todavia não influenciaram na produtividade do arroz no segundo ano; os cultivos antecessores de Crotalaria juncea e Pennisetum glaucum com escarificação, seguida de cultivo do arroz, proporcionaram incrementos na produtividade do feijão de inverno em sucessão; a entressafra de Pennisetum glaucum, Crotalaria juncea e Urochloa ruziziensis independentes da... / The planning succession allied cover crops in the off-season and sporadic mechanical decompression are options to minimize compaction soil surface under, as well as directly providing improvements in soil attributes in no-tillage system (NTS) deployed in the Savannah South Mato Grossense, advocating the sustainability of the production system. The objective was to evaluate the mechanical soil decompression, development and yield of cover crops in the spring in NTS, and also in the growth and yield of rice crop upland and common bean winter in succession, in addition to changes in chemical and physical attributes of the soil, after each cultivation of annual crops. The study was conducted in Selvíria, MS, in 2012/13 e 2013/14, in a Savannah South Mato Grossense, Oxisol, clayey, in a randomized block design arranged in a factorial design 5x2 for rice and common bean, with four replications. The treatments were a combination of five cover crops (fallow (control), Cajanus cajan, Crotalaria juncea, Pennisetum glaucum and Urochloa ruziziensis) with and without mechanical soil scarification. The species of Pennisetum glaucum, regardless of chiseling in NTS promoted greater dry matter yield and accumulation of macronutrients in the shoot as well as greater persistence of plant debris; the chiseling in NTS and the previous cropping Cajanus cajan provided higher yields of rice in the first year, but did not influence the rice yield in the second year; crops predecessors Crotalaria juncea and Pennisetum glaucum with scarification, followed by rice cultivation, provided increases in bean commun yield winter in succession; the off-Pennisetum glaucum, Crotalaria juncea and Urochloa ruziziensis independent of scarification Urochloa ruziziensis provided improvements more frequently in chemical attributes in the soil profile; the chiseling in NTS promoted greater porosity, and reduced the density and soil ...

Made available in DSpace on 2014-06-11T19:35:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-23Bitstream added on 2014-06-13T20:06:57Z : No. of bitstreams: 1 nakayama_ft_dr_ilha.pdf: 450316 bytes, checksum: 082c50b94e8da5be2360a3aaf96e6438 (MD5) / Universidade Estadual Paulista (UNESP) / A semeadura direta vem a cada ano ampliando sua área agrícola no cerrado e é imprescindível a manutenção da palhada para o sucesso desta tecnologia, devendo respectivamente atender à necessidade da cultura e promover a conservação do solo. Desta forma, este trabalho teve por objetivo avaliar os efeitos do consórcio de plantas utilizadas como coberturas vegetais no desenvolvimento e produtividade do algodoeiro bem como sua contribuição no condicionamento químico e físico do solo. O delineamento experimental empregado foi o de blocos ao acaso com quatro repetições no esquema fatorial 4x4 compreendendo os fatores: 1. Dicotiledôneas: a- Cajanus cajan, b- Crotalaria juncea, c- Raphanus sativus, d- “sem dicotiledônea”; 2. Monocotiledôneas: a- Avena strigosa, b- Pennisetum glaucum, c- Brachiaria ruziziensis, d- “sem monocotiledônea”. Foram realizadas avaliações de fitomassa seca e cobertura do solo nas coberturas vegetais e a influência na química e física do solo sendo analisadas a porosidade e resistência à penetração. Após o manejo da palhada foi semeada a cultura do algodão nas parcelas experimentais no qual foram avaliados os aspectos agronômicos da cultura. De acordo com os resultados obtidos, os consórcios entre monocotiledôneas e dicotiledôneas ou ao cultivo exclusivo de monocotiledöneas apresentam maiores percentagens de cobertura do solo se comparado ao cultivo isolado de dicotiledôneas. As maiores produtividades de fitomassa seca de plantas de cobertura foram proporcionadas pelo cultivo exclusivo de milheto e milheto associado ao guandu. A aveia preta proporcionou os menores valores de resistëncia a penetraçäo para as camadas superficiais do solo (0-15 e 15-30 cm); e os tratamentos dicotiledonares destacando- se o nabo forrageiro proporcionaram uma diminuição... / The practice of no tillage are expanding year why year in Cerrado and is essential the crop residues maintenance for success of this technology, respectively meet the needs of culture and promote soil conservation. The objective work was to evaluate the effects of the consortium of cover crops in the development and yield of cotton as well as his contribution to the chemical and physical conditioning of the soil. The experimental design was a randomized block design with four replicates in a 4x4 factorial factors including: 1. Dicotyledons: a- Cajanus cajan, b- Crotalaria juncea, c- Raphanus sativus, d- “no dicotyledons”; 2. Monocotyledons: a- Avena strigosa, b- Pennisetum glaucum, c- Brachiaria ruziziensis, d- “no monocotyledons”. Were evaluated vegetation cover, dry matter and the influence on chemical and physical soil being analyzed porosity and penetration resistance. After handling of the cover crop was sown cotton in the experimental plots in which we evaluated the agronomic aspects of culture. According to the results obtained, the consortium between monocots and dicots or monocots unique culture have higher percentages of soil coverage as compared to isolated from dicotyledons. The highest yield of dry biomass of cover crops were provided exclusively by the cultivation of Pennisetum glaucum and Pennisetum glaucum associated with Cajanus cajan. The Avena strigosa provided the lowest values of penetration resistance to the soil surface layers (0-15 and 15-30 cm) and dicots treatments distinguished Raphanus sativus provided a decrease in penetration resistance for layers 30 -45 and 45-60 cm. Pennisetum glaucum provided the highest values for total porosity and macroporosity in the 0-20 cm layer. Treatments isolated Raphanus sativus, Raphanus sativus associated Brachiaria ruziziensis or until Pennisetum glaucum sown in the month of July provided the highest yield for Deltaopal cotton in the Cerrado conditions