The purpose of the study was to find alternatives to fences by comparing the frequency of damages on different configurations of chemical treated, mechanically protected and untreated hybrid aspen seedlings, planted on agricultural land. The study also explored whether anthropogenic disturbance (proximity to roads and buildings) had any effect on the frequency of seedlings damages. The study was conducted as a quantitative study with field measurements over the course of a year, in two sample plots with hybrid aspen seedlings planted in May 2016 in Vimmerby kommun, Kalmar län. The field data was compiled into Excel and compared for differences between treatments and proximity to anthropogenic disturbance. The result showed that seedlings closer to anthropogenic disturbance showed a lower frequency of damage. There was no significant difference between the mechanical (Taimitassu) and chemical (Arbinol B) seedling protection. The highest frequency of damages occurred in the summer, peaking in July. In conclusion, when choosing a place to plant hybrid aspen, there should be anthropogenic disturbance to minimize the frequency of browsing.

A ocorrência de inundações e alagamentos em Porto Alegre é objeto de estudo de diversas pesquisas, as condições climáticas e o relevo do município propiciam que esses fenômenos sejam recorrentes. Esta pesquisa objetiva analisar as intervenções realizadas pelo uso e ocupação da terra na morfologia original e na dinâmica geomorfológica no entorno de vias do município de Porto Alegre onde é identificada a concentração dos eventos de inundação e/ou alagamento que causam interferências no trânsito. Como contextualização histórica foram realizadas a análise da expansão urbana do município de Porto Alegre e a verificação da ocorrência de inundações e/ou alagamentos no município. A partir da análise dos dados climáticos foram selecionadas datas nas quais houve um total pluviométrico acima de 30 mm. Com isso foram identificadas as áreas de concentração dos eventos que causaram alteração no trânsito, a saber: a bacia hidrográfica do arroio Almirante Tamandaré e a bacia hidrográfica do arroio Cavalhada (a com maior número de ocorrências na zona sul de Porto Alegre). A partir da seleção dessas áreas mapeou-se a morfologia original, caracterizando a morfodinâmica anterior às intervenções antrópicas. A morfologia original dessas áreas, quando analisada em conjunto com dados históricos, remete à condição potencial aos alagamentos e/ou inundações. Posteriormente foram mapeados o uso e ocupação da terra atual das áreas de estudo, destacando a densidade de ocupação dos lotes, assim pode-se analisar a relação entre as intervenções na dinâmica geomorfológica originalmente existente e a concentração de alagamentos nessas áreas. As intervenções realizadas pelo processo de ocupação desses espaços acarretaram mudanças na morfologia original que interferiram na dinâmica superficial, especialmente no que se refere ao escoamento das águas pluviais, podendo gerar ou potencializar os eventos de alagamento e inundações na área de estudo. / The occurrence of floods and inundation in Porto Alegre is the object of study of several research efforts. These are recurrent events determined by the climatic conditions and topography of the city. The present research aims at analyzing the interventions made by the use and occupation of the land and its effects on the original morphology and geomorphology around the city of Porto Alegre, where the concentration of floods and / or inundation are identified and the impacts on urban traffic evaluated. As a historical perspective, the analysis is made of the urban expansion of the city of Porto Alegre, that focus on the descrition of flooding and / or inundation occurences in the city. From the analysis of climate database, specifc dates were selected in which the rainfall was higher than 30 mm. The areas of concentration of events that caused changes in traffic, were identified namely: the Admiral Tamandaré hydrographic system and the Cavalhada stream (with the highest number of events in the southern area of Porto Alegre). From the selection of these areas, the original morphology was mapped allowing the characterization of morphodynamic features previous to human interventions. The original morphology of these areas, were analyzed in conjunction with the historical database, which enabled the potential for flooding and / or inundation to be identified. Subsequently the use and occupation of the current areas of study were mapped, highlighting the density of occupation, in a way of assessing the relationship between interventions in the original geomorphological dynamics and concentration of flooding in these areas. The interventions by the process of occupation in these areas led to changes in the original morphology that interfered in the dynamic surface, especially in regard to stormwater runoff. This may generate or enhance the event of flooding and inundation in the area of study.

In 2015-2016 Kwa-Zulu Natal (KZN) and other provinces in South Africa suffered from drought conditions. Drought can have negative impacts on the environment, society and the economy. Climate change is predicted to exacerbate extreme events such as droughts that would adversely affect already vulnerable regions such as KZN. The main aim of this study is to implement the attribution procedure, to determine if climate change has contributed to the 2015-2016 hydrological drought in selected KZN catchments. Methodology of the study followed a general framework of implementation of hydrological attribution experiments with climate data obtained from attribution simulations with HadAM3p global climate model. Prior to simulations in attribution mode, QSWAT model was set up for the study area and calibrated using SWAT-CUP and SUFI-2. Calibration results were poor but the model could be applied in the context of this study, under certain constraints. Results of attribution experiments revealed that for all 3 subbasins studied no increase of risk was observed and hence no influence of climate change on the 2015-2016 magnitude of drought for selected catchments was concluded by this study. These results are limited, as they are based on climate attribution experiments with only one climate model, rather than with a multi-model ensemble. Also, QSWAT model, in its implementation with generic climate data is of limited use in attribution (or hydrological) simulations as even after calibration the model performs poorly.

Globally emphasis has been given to identify emerging and re-emerging pathogens. Rapid urban expansion creates a problem which is two-fold. Firstly, increasing slum living conditions due to inadequate rate of infrastructure development results in an increased reliance on natural resources, including the capture and consumption of surrounding wildlife to subsist, thereby facilitating the transfer of emergent zoonotic pathogens. Secondly, through activities such as pollution or alien species introductions, the rapid transformation of once pristine environments, alters natural systems, potentially exposing these environments to new bacterial pathogens. Therefore, the main aim of this study was to assess overlooked bacterial species harboured by four host species (Bathyergus suillus, Georychus capensis, Cryptomys hottentotus hottentotus and Fukomys damarensis) belonging to the subterranean rodent family Bathyergidae, which inhabit an environment well-suited for an array of bacterial species, and which varied in their exposure to human settlements. Bacterial prevalence and diversity was initially evaluated using broad-range PCR techniques in combination with nucleotide sequencing. This revealed high levels of bacterial prevalence (82.91%) and mixed infections (22.60%) in bathyergid species. Two bacterial groups, the Bacillus cereus complex (a group of soil-dwelling bacterial strains with pathogenic potential with an overall prevalence of 8.55%) and haemotropic Mycoplasma strains (vector-borne bacterial strains of zoonotic potential with an overall prevalence of 1.28%) were subsequently selected for further genetic analysis with genus and species-specific PCRs. Bacillus molecular screening and phylogenetic analyses was achieved by targeting four gene regions with seven published primer assays and two novel PCR assays. This enabled identification of two B. cereus complex strains in bathyergid lungs and revealed an overall B. cereus complex prevalence of 17.95% for the 234 bathyergid lung samples screened. Bacillus genome prevalence was significantly higher in B. suillus individuals (45.35%), sampled in a peri-urban environment, compared to the other bathyergid species sampled from pristine habitats (ranging from 0% - 4.44%). Anthropogenic activities in the area where B. suillus was sampled could, at least partially, attribute to the perceived difference between urban and naturally sampled bathyergid species, highlighting the role of B. suillus to act as both a reservoir of potentially zoonotic pathogens and as a sentinel for anthropogenic soiling. Mycoplasma molecular screening using three different PCR assays, all targeting the 16S rRNA gene region, confirmed an overall haemotropic Mycoplasma prevalence of 24.13% in the 286 bathyergid organs (lung, spleen and liver) screened. A significantly higher prevalence and diversity of haemotropic Mycoplasma strains was found in B. suillus lungs (41.86%) compared to its naturally occurring relatives (ranging from 0%-36%). Phylogenetic analyses identified six novel haemotropic Mycoplasma strains, all grouping within a discrete monophyletic cluster, sister to Mycoplasma coccoides, and comprising two well-supported sub-clusters. The human introduction of commensal rodents harbouring Mycoplasma strains transferred through cosmopolitan arthropod vectors to indigenous bathyergids, likely underlies the higher prevalence in urban areas, although other biotic and abiotic factors affecting ectoparasite load also merit consideration. The data generated by the current study indicate the need to identify largely overlooked and potentially zoonotic bacterial pathogens in subterranean mammals and emphasises the importance of monitoring anthropogenically-introduced, opportunistic pathogens and the threats they pose to vulnerable communities and co-occurring, free-living animal species / Dissertation (MSc)--University of Pretoria, 2017. / Airports Company of South Africa (ACSA) / National Research Foundation (NRF) / Zoology and Entomology / MSc / Unrestricted

Wildlife managers use models to aid in predicting high risk areas for human and black bear (Ursus americanus) interactions (HBI). These tools help managers implement management strategies to minimize HBI. Over 3,000 incidents of HBI were compiled from management reports at Great Smoky Mountains National Park (GSMNP) during 1998-2011, a park with 9-10.2 million visitors per year and a black bear population of about 1,600 bears. We used data from bear management reports along with annual visitor use, mast and bear abundance data to develop a series of generalized linear models to assess the spatial and temporal factors affecting HBI. Although HBI occurred throughout the GSMNP, 50% of all HBI occurred in five areas. The best predictor variables of HBI across four subsets of models included interaction between mast production and number of park visitors, month, vegetation cover, visitor activity, and bear abundance. Although there was not a clear relationship between visitor use and mast abundance, the number of park visitors was always relatively high and HBI increased substantially in poor mast years. HBI was more frequent during summer months when park visitation rates and more people and food were present overnight in frontcountry and backcountry camping areas. Over 43% of HBI in hemlock forests were serious. Bear abundance data were not a strong predictor of HBI, and bear bait stations may not provide a sensitive index to bear abundance. GSMNP uses different strategies for managing HBI to protect visitors and bears. In 1991, bear proof waste disposal containers and food storage devices were placed in camping and picnic areas. In combination with aversive conditioning, HBI decreased in some areas of the park. We recommend that proactive bear management programs including education, enforcement of park regulations, and aggressive aversion conditioning of bears be implemented at the identified HBI high risk areas to provide a safer environment for both people and bears in GSMNP.

Arsenic (As) and nitrate (NO3) are common contaminants in groundwater that are introduced through a variety of natural and anthropogenic sources. In this study we investigated the sources and distribution of As and NO3 in Goshen Valley, Utah, USA. Goshen Valley is a semi-arid alluvial basin that is impacted by geothermal waters, agriculture, urban development, and legacy mining. In this study we sampled surface water, springs, and wells to analyze concentrations of major ions, trace elements (As, B, Ba, Ca, Fe, K, Li, Mg, Mn, Mo, Pb, Si, Sr, Zn), and stable isotopes in water (δ18O and δD). A subset of samples were also analyzed for 87Sr/86Sr, δ34S, and tritium (3H). Major ion concentrations showed high spatial variability ranging from freshwater to brines, with the highest concentrations found in springs discharging from playa sediments. Likewise, the highest trace element concentrations, including As, were found in the playa-impacted springs. Elevated NO3 concentrations were found in springs and wells in agricultural areas of the valley. δ18O and δD values range from -0.90238 to -17.6 and -37.0891 to -134.5 respectively and represent that the valley contains old groundwater, evaporative surface water, and mixed water signatures in multiple wells. Tritium values range from 0.5 to 7.8 and further show the diversity of water in the valley by indicating old, young, and mixtures of old and young waters. Variations in 87Sr/86Sr were used to evaluate flowpaths of waters with elevated As. 87Sr/86Sr ratios suggest that the groundwater has interacted with a mixture of lithologic units including Tertiary volcanics, Paleozoic carbonates, and Quaternary alluvial/lacustrine fill. Correlations with As and playa affected springs indicate playa sediments as a major As source. The As found in wells has no apparent elemental correlations or spatial patterns and is likely due to the naturally occurring As in the valley alluvium and carbonate units. NO3 in the valley is concentrated in agricultural areas and is likely due to fertilizers, livestock, and alfalfa crops. Of all the potential contaminant sources, the data suggests that the major source of As is the saline playa soils and the major source of NO3 is agricultural activities in the valley.

No description available.

Eutrophication of the Baltic Sea has been an issue for decades and the pollution constantly continues with oxygen deficient bottoms and a damaged marine life as a result. One of the main causes of eutrophication are elevated levels of the nutrient phosphorus. Phosphorus leaks to the sea from various human activities such as agriculture, animal farming and sewage. In Sweden, the onsite wastewater treatment systems are a big problem since they load the Baltic Sea with nearly as much phosphorus as all Swedish municipal wastewater treatment plants. The need for a reduced impact on the Baltic Sea is major and the individual wastewater treatment systems must therefore be looked over. While phosphorus is a contributing factor to eutrophication, it is one of the most important nutrients for all life. Phosphorus builds up our DNA, helps transport of various substances in and out of our cells and provides energy to the cell's processes. We would simply not be able to survive without phosphorus. We ingest phosphorus through the food we eat, which in turn is dependent on fertilizers containing phosphorus. Phosphorus is mined from phosphate ore and the majority of it is used to produce fertilizers. Unfortunately, phosphate ore is not a finite resource and in the last few years it has been realized that the economically extractable phosphorus is a dwindling resource. To be able to produce food for the world's growing population, we need to find ways to recycle phosphorus. In individual drainage systems there is a large potential to catch up phosphorus and then reuse it on agricultural land. This thesis deals with the problems of onsite wastewater treatment systems and suggests measures to improve their status. Ways to recycle phosphorus in combination with having a well-functioning drainage is being investigated and difficulties about the regulations are being discussed. To recover phosphorus and at the same time reduce the burden on the environment should be seen as an incredibly important action, since our sea’s health is acute but lack of the nutrient could have devastating consequences.

It has been estimated that approximately half of all anthropogenic fossil fuel carbon dioxide (CO2) emissions have been absorbed by the oceans. Air-sea gas exchange of CO2 and the buffering capacity of seawater allows the oceans to store significant amounts of dissolved inorganic carbon (DIC; ~38,000 GtC). The Arctic Ocean is currently warming at double the rate of the rest of the planet, yet the effect of climate change on the Arctic marine carbon cycle remains unconstrained. Recent work suggests that Arctic marine environments are a carbon sink for the majority of the year, and plays a key role in storing anthropogenic carbon below the mixed layer. Baffin Bay is a semi-enclosed, Arctic basin that supplies cold surface water to the Labrador Sea; a critical region for North Atlantic deep-water formation. While the physical oceanography of surface Baffin Bay is well characterized, less is known about deep water formation mechanisms and its ventilation age. The few residence times for Baffin Bay Deep Water (BBDW) range widely from 20-1450 years. Improved residence time estimates are essential for understanding the role Baffin Bay plays in the Arctic carbon cycle and how this region will respond to climate change. Radiocarbon (D14C) and stable carbon (δ13C) measurements of DIC are powerful tools for parameterizing water mass sources, aging and residence times. However, very few DIC Δ14C and d13C data have been reported in the Arctic Ocean, comprising only a handful of stations in the Eurasian Basin, Canadian Basin, and Beaufort Sea. With this goal in mind, we conducted a study in which DIC samples were collected aboard the CCGS Amundsen in 2019 for δ13C and Δ14C analysis. DIC δ13C and D14C values ranged from 0.68‰ to +1.90‰ and -90.0‰ to +29.8‰, respectively. Surface DIC δ13C values were +0.69‰ to +1.90‰, while deep (>100m) d13C values ranged -0.01 to -0.68‰. Significant linear correlations were found for δ13C and potential density, suggesting DIC δ13C is an effective water mass and carbon source tracer in Baffin Bay. Surface DIC Δ14C values ranged -5.4‰ to +22.9‰, while deep DIC (>1400m) DIC Δ14C averaged -82.2 8.5‰ (n = 9). Much larger surface to deep gradients in DIC Δ14C are observed in Baffin Bay vs. that of the North Atlantic Ocean, suggesting significant aging of BBDW. Next, we used the potential alkalinity method (Palk) and the ΔC* method to quantify the amount of “bomb” 14C and anthropogenic C (DICanth) to model “natural” DIC Δ14C profiles. Both Palk and ΔC* proxies had high errors in cold, low salinity surface water. In particular, surface (<400m) Δ14Cbomb was overestimated at all stations. However, both proxies did not indicate Δ14Cbomb or DICanth contributions below 1000m. Two 14C residence times were estimated based on two proposed mechanisms of BBDW formation. A residence time of 690 +/- 35 years was estimated assuming surface brine rejection in Nares Strait is the main source of BBDW. Another plausible source of BBDW is the entrainment of dense north Atlantic Water over Davis Strait mixed with brine enriched surface water. A comparison of DICanth and Δ14Cbomb corrected deep DIC Δ14C values from the North Atlantic (GO SHIP A16N) to BBDW, resulted in a residence time of 360 +/- 35 years. These residence times (360-690 years) provide new constraints on the ventilation age of deep Baffin Bay and suggest this basin has the potential to store carbon for centuries.

Global warming and climate change deeply influence weather and climate extremes, causing substantial property damage and loss every year around the world. Given the importance of heating differences between low-latitude and Arctic regions, which produce heat sources and cold sources that each influence global circulations, we investigate three extreme weather events in different regions in order to better understand the possible connections between extreme events and global circulation changes. This study begins with climate variations in the low-latitude western North Pacific. In early summer, the timing of the wet season has shifted from late May to early June since 1979. This change influences the water supply in Southeast Asia. Our analysis results indicate that the increase in global temperatures is suggested to have induced this change. During the hurricane season, deep convection in the western North Pacific has a 20-year frequency of timing variations, oscillating between July and August and influencing hurricane activity. These variations have not been previously identified and do not have any driven forcings, but a precursor deep-convection signal is found in the spring. Mid-latitude weather and climate can be influenced by tropical deep convection through the Pacific North American teleconnection. Our analysis results suggest that the wintertime Californian drought is mainly modulated by a teleconnection pattern from the tropics and natural variations in North Pacific circulation. Another key factor that influences mid-latitude circulation is Arctic temperature variations. We find an increase in the subseasonal Arctic warming event, suggesting more weather extremes in the mid-latitudes. Evidence suggests that sea-ice loss and the increase in tropical deep convection results in the increased likelihood of a subseasonal Arctic warming event.