No description available.

Coral reefs have declined globally due to anthropogenic stressors increasing the frequency and severity of bleaching and disease events. In 2014, a stony coral tissue loss disease (SCTLD) outbreak occurred off the coast of southeast Florida and subsequently spread throughout the region. Data collected by the Southeast Florida Reef Evaluation and Monitoring Project (SECREMP) were used to examine the regional impacts of the disease event on the Southeast Florida stony coral assemblage. A long-term annual monitoring project, SECREMP samples permanent sites along the Southeast Florida Reef Tract (SEFRT) from Miami-Dade County north to Martin County. Analysis of stony coral demographic data from 21 sites revealed regional SCTLD prevalence increased significantly, and significant region-wide declines in stony coral diversity and density were observed. From 2014 to 2018, species-specific susceptibility to the disease were evident, with Meandrina meandritesand Dichocoenia stokesiboth losing > 90% of all live tissue by 2016. The reef building, complexity-contributing species Montastraea cavernosaand Orbicellaspp. lost significant tissue (55% and 70% respectively) as a result of this disease event. Overall, up to 64% of all live tissue was lost and at least 11 of 28 total species were impacted by SCTLD. Of the colonies that suffered complete mortality, many were among the largest individuals in the dataset. Loss of large, sexually mature colonies lowers reproductive capabilities and thus severely inhibits the potential for recovery. Juvenile surveys showed many of the large, structurally complex species had little to no juveniles within the sample sites, while eurytopic generalist species made up more than 76% of all juveniles. This disease event resulted in acute mortality and altered ecosystem function to the point where recovery is uncertain. To facilitate recovery, local resource managers need to understand the severity of the disease outbreak on the coral assemblage and mitigate local anthropogenic stressors.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21376号 / 農博第2300号 / 新制||農||1068(附属図書館) / 学位論文||H30||N5149(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 井鷺 裕司, 教授 神﨑 護, 教授 北島 薫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

The Tushar Mountains of Utah provide essential alpine habitat to a variety of flora and fauna, including 27 endemic plant species and several ungulates (mountain goats, deer, elk, cattle). These ungulates were observed throughout two growing seasons and field analyses were conducted to assess foraging selection. Overall, most ungulates, especially large nursery herds, tended to prefer foraging amongst alpine regions within the Bullion volcanic of the Tushars, which is characterized by denser vegetation than the Belknap volcanic region. Mountain goats and deer were most frequently observed foraging within the Tushar alpine habitat; however, elk and domestic cattle were also observed. Mountain goats preferred foraging at higher elevations than other ungulates and shared the most dietary overlap with deer. Out of the 27 plant species endemic to this region, only Castilleja parvula var. parvula, commonly known as the Tushar paintbrush, was encountered frequently utilized by ungulates. This plant species was also observed being eaten by a variety of rodents and lagomorphs. Long-term monitoring plots were established in four different populations of C. parvula var. parvula across the Bullion volcanic range of the Tushars. These plots were revisited on a yearly basis and used to ascertain demographic data, which will shed light on population trends over time. A variety of different measurements were used to better understand the biology and habitat requirements of this rare plant species. Although the four monitored populations share many similarities, they each have their own site characteristics, local densities, relative plant communities, and potential threats. Further monitoring is necessary to better understand trends and assess the level of the various threats to C. parvula var. parvula populations.

No description available.

Orientador: Igor Paiva Ramos / Resumo: A formação de reservatórios está entre os principais responsáveis pela perda de biodiversidade, uma vez que contribuem com a degradação de habitats, perda de conectividade fluvial, modificações no fluxo hidrológico e a introdução de espécies não nativas. Desta forma, as questões endereçadas deste estudo foram: (i) Testar o ajuste de diversos modelos de distribuição de abundância de espécies (SAD) aos dados do monitoramento ictiológico de uma cascata de reservatórios no alto Paraná. Ainda, avaliar se as assembleias de peixes dos reservatórios possuem padrão semelhante de riqueza e complexidade, através de análise dos modelos SAD e das curvas de acumulação de espécies e a comparação do parâmetro α do modelo gambin.; (ii) Determinar a importância de tributários não barrados para a conservação da ictiofauna de reservatórios e; (iii) Avaliar o papel de um sistema de transposição de peixes (STP) na restauração de conectividade fluvial. Foram utilizados dados do monitoramento ictiológico realizados em 14 locais ao longo dos reservatórios de Ilha Solteira, Três Irmãos, Eng. Souza Dias (Jupiá) e Eng. Sergio Motta (Porto Primavera), bacia do alto rio Paraná. Como resultados, (i) a análise comparativa das curvas de acumulação de espécies e das SAD evidencia as diferenças entre as assembleias dos reservatórios avaliados. Três Irmãos e Ilha Solteira apresentaram menor riqueza de espécies e possuem poucas espécies muito abundantes, Jupiá apresenta maior riqueza com muitas espécies de captu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The formation of reservoirs is among the main responsible for the biodiversity loss, as they contribute to the degradation of habitats, loss of river connectivity, changes in hydrological flow and the introduction of non-native species. In this way, the questions addressed in this study were: (i)To test the adjustment of several species abundance distribution models (SAD) to the ichthyological monitoring data of a reservoir cascade in the upper Paraná. Also, to evaluate if the fish assemblages of the reservoirs have similar pattern of richness and complexity, through analysis of the SAD models and the species accumulation curves and the comparison of the parameter α of the gambin model; (ii) To determine the importance of undammed tributaries for the conservation of the ichthyofauna of reservoirs; and (iii) To evaluate the role of a fishway in the restoration of fluvial connectivity. A total of 14 sites were surveyed in the Ilha Solteira, Três Irmãos, Eng. Souza Dias (Jupiá) and Eng. Sergio Motta (Porto Primavera), upper Paraná River. As results, (i)The comparative analysis of species accumulation curves and SAD shows the differences between the assemblies of the evaluated reservoirs. Três Irmãos and Ilha Solteira showed a lower abundance of species and have few abundant species, while Jupiá is richer with many rare species. Porto Primavera, on the other hand, presented similar richness to Jupiá, but with few rare and few dominant species, with a distribution close to the log... (Complete abstract click electronic access below) / Doutor

L’Arctique se réchauffe deux fois plus vite que le reste du monde, entrainant des changements majeurs des écosystèmes marins. Par exemple, l’étendue de la banquise diminue, et la distribution des masses d’air change, modifiant les régimes de vents et de précipitations. Parallèlement à ces changements climatiques, l’Arctique est soumise à une pollution anthropique croissante amenée par les circulations atmosphériques et océaniques, et accentuée par le développement des activités humaines locales. Dans ce contexte, il est urgent de comprendre les impacts écologiques de ces modifications environnementales sur les espèces de cette région. Les mergules nains (Alle alle) sont les oiseaux marins les plus abondants de l’Arctique, et des acteurs clés des réseaux trophiques côtiers. Bien que des travaux récents aient suggéré une forte résilience de ces organismes aux changements globaux, une étude approfondie permettant de comprendre de manière détaillée l’impact de ces changements était essentielle. Au cours de ce travail de thèse, nous avons donc utilisé une approche pluridisciplinaire (écologie alimentaire, écotoxicologie, bioénergétique, écologie du déplacement) menée à long terme afin de caractériser la sensibilité des mergules nains aux changements de leur environnement pendant la saison de reproduction (été) et en hiver. Nous avons pour cela étudié une population de mergules nains au Groenland Est. Nos résultats montrent que les mergules sont fortement impactés par les changements en cours. Pendant la période de reproduction, leurs proies changent et leur effort de plongée augmente en l’absence de banquise, même s’ils demeurent fidèles à leur zone de nourrissage sur le talus continental. Ceci tend à diminuer leur condition corporelle et celle de leur poussin, mais n’impacte pas leur survie. En hiver, les mergules nains optimisent leur migration et leur distribution en fonction de la distribution de leurs proies et de leur paysage énergétique. Ainsi, nos modèles prédictifs indiquent qu’un réchauffement de l’Atlantique nord pourrait être bénéfique pour les populations en diminuant leurs besoins énergétiques. Enfin, nous avons trouvé que les mergules nains consomment des microplastiques, et ce en les confondant avec leurs proies. Cette source de pollution supplémentaire pourrait augmenter avec la fonte de la banquise qui libère des microplastiques jusque-là stockés dans la glace. Ce travail souligne l’importance des programmes à long terme pour l’étude des impacts des changements globaux. / The Arctic is warming twice faster than the rest of the world, leading to major changes for marine ecosystems. For example, sea-ice extent is decreasing, and air mass distribution is changing, thus modifying wind and precipitation regimes. In parallel, the Arctic is subject to increasing anthropogenic pollution carried by atmospheric and oceanic circulation, and accentuated by the development of local human activities. In this context, there is an urgent need to understand the ecological impacts of these environmental modifications on the species of this region. Little auks (Alle alle) are the most abundant seabird in the Arctic, and key players of coastal food webs. Although recent works suggested a high resiliency of little auks to global changes, a comprehensive study was needed to understand in detail the impacts of these changes. Through this work, we used a multidisciplinary approach (diet ecology, ecotoxicology, bioenergetics, foraging ecology) on the long term to characterize little auk sensitivity to environmental changes during the breeding season (summer) and in winter. We therefore studied a little auk population in East Greenland. Our results show that little auks are indeed impacted by ongoing changes. During the breeding season, their prey change and their diving effort increase when there is no sea-ice, even if they remain faithful to their feeding grounds on the continental slope. This tends to decrease their body condition and that of their chick, but does not impact their survival. In winter, little auks optimize their migration and their distribution according to the distribution of their prey and their energetic landscape. Therefore, our predictive models indicate that a warming of the North Atlantic could be benefic for little auk populations, by reducing their energetic needs. Finally, we found that little auks ingest microplastics, by confusing them with their prey. This additional source of pollution could increase with sea-ice loss that release microplastics stocked in the ice. This work underlines the importance of long term monitoring programs for the study of global change impacts.

Thesis rises from an actual needs to make standard of practice for assessment an existing arch railway masonry bridges on the basis of condition long term monitoring. Bridge assessment is a part of any inspection, especially in case of doubts arising during inspections due to heavy defects, increase of axle load or increase of train frequency, which may influence the structural safety, traffic safety or durability of a bridge. There are possibilities for utilization of monitoring results for assessment in case of investigation data absece. An important option is assessment based on satisfactory past performance by ČSN ISO 13822, chapter 8.

No description available.

The rehabilitation and restoration of degraded landscapes adjacent to gold tailings disposal facilities (TDFs) that have suffered loss of efficiency through anthropogenic forces has become a primary concern to environmental sciences and management in recent decades. Due to the lack of environmental legislation and enforcement thereof, minimal surface rehabilitation took place on the Mine Waste Solutions (MWS) No. 5 TDF prior to 1992, a commonplace occurrence in South Africa at the time. In 2000, MWS intervened and committed to the rehabilitation of the entire site with profits generated by the reprocessing (extraction of residual gold and uranium) of certain TDFs. However, the adjacent grazing land north of the MWS No. 5 TDF had already been subjected to pollution from the TDF which resulted in a pollution plume on the land. Although it has been inactive since April 2011, the pollution plume can be seen from the north-eastern corner of MWS No. 5 TDF, with a north-eastern/south-western direction on the farm Stilfontein. During dry periods, significant amounts of sulphate salts accumulate on the soil surface on the farm Stilfontein over a distance of at least 3.5 km from the TDF. The presence of sulphate salts in association with gold TDFs is highly common but not particularly common, in the chert-poor dolomites of the Oaktree Formation itself, in which the presence of sulphate salts is a rarity. The primary concern of this study was to determine both the quantitative and extent of the pollution observed on the farm Stilfontein over a period of 30 months via monthly monitoring of the different soil geochemical assessments across twelve fixed points, and quarterly interval assessments of three transect lines. In addition, the study was also concerned with the identification of potential linear structure anomalies associated with the pollution plume and weathered zones (fractures, joints and cavities) in the Oaktree Formation dolomites. These zones may be associated with, or may result in, the pollution extending over the area despite a topography as well as geological dip and strike that is adverse. These features and weathered zones create pathways for groundwater to flow and it was anticipated that, if present, these anomalies and weathered zones may be primary contributing factors to the pollution plume forming in a north-easterly direction and extending over the farm Stilfontein. The MWS No. 5 TDF has a hydraulic pressure head of approximately 40 m; the elevations of the north-eastern corner of the TDF and fixed point (FP) 8 (the farthest FP from the TDF) are 1368 m and 1360 m respectively, falling in close range of each other. It is anticipated that as the TDF material dries, the phreatic water level inside the TDF will lower; causing the pressure exerted by the hydraulic head of the TDF to lower over time, which will eventually end the pollution process on the soil. This study discusses the results of a holistic approach towards the evaluation of soil, vegetation and water pollution by utilizing soil quality parameters and indicators, geohydrology, geophysical surveys, Landscape Function Analysis (LFA) and other means of vegetation assessments. Salt accumulation on the soil surface was common in specific areas from 2010 – 2012. X ray diffraction (XRD) analyses confirmed that the salts originated from the No. 5 TDF due to the similarity in mineralogy. The pH values from the start of the 30-month monitoring period remained neutral to slightly alkaline due to the neutralising effect of the dolomitic bedrock. The electrical conductivity (EC) values of the soil decreased significantly from 2010 to 2014; during dry seasons since 2012, no sulphate salts accumulated on the soil surface. Joints, fractures and cavities were found within the bedrock dolomites which created pathways for the polluted TDF water and groundwater to flow towards the study area. It was also established that there were no adverse effects on the natural vegetation, other than encroachment by Seriphium plumosum which affected the grazing quality (overgrazed sites) of the area. It was therefore concluded that after the TDF became dormant in April 2011, the pollution plume in this area is decreasing in magnitude and severity due the lowering of the phreatic water level inside the TDF to significantly lower levels. Consequently, the decrease of the hydraulic pressure head of the TDF as well as rainwater infiltration and high percolation due to the presence of fractures, joints and cavities in the dolomites resulted in the leaching of the sulphate salts to a significant extent. It was also concluded that while there were no apparent adverse effects of the pollution on the functionality of the land, additional monitoring and maintenance would be required for at least the next five years in order to ensure the continuance of current conditions. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015