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1
Nordin, Ida. "Multiple tipping points in the climate system : Implications for climate policy." Thesis, Umeå universitet, Nationalekonomi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-92603.
Повний текст джерела
2
Mason, Suzanna. "Examining species' responses to climate change across multiple taxonomic groups." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/19677/.
Повний текст джерелаАнотація:
Many species are responding to anthropogenic climate change by shifting their ranges to higher latitudes. Understanding the factors that drive species’ responses will help ecologists and conservationists develop strategies to avoid negative climate change impacts. I investigated shifts at the northern (cool) range margins of 1573 southerly-distributed species from 21 animal groups in Great Britain, over the past four decades. My findings confirm continued polewards range shifts (18 km decade-1 over 1986-2010). I then concentrated on 347 British species from 14 invertebrate taxa, discovering considerable variation in the distances moved within each taxonomic group (but not between groups). I used land cover data and distribution records to determine each species’ habitat specialism, and to quantify habitat availability. Habitat availability explained up to half of the range shift variation. I conclude that interactions between species’ attributes and the environment are important determinants of range shifts. Abundance data are used to study species’ responses to environmental changes but, unlike distribution records, are not available for many taxa. Data from 33 British butterflies revealed a strong correlation between mean year-to-year changes in total number of distribution records and mean year-to-year change in abundance, suggesting that distribution data can be used to identify species’ population variability, and ecologists can investigate the influence of climate change on species’ populations without abundance data. I conclude that rates of range shifting are highly variable among species, suggesting that understanding species-specific range shifts is necessary to assess species’ responses to climate change. The availability of habitat at the range margin strongly influence rates of range shifting which suggests the need for habitat management aimed at facilitating species’ dispersal and population establishment. Citizen science data have potential to assist ecologists in examining species’ responses to climate change and in identifying, predicting and mitigating climate change impacts in the future.
3
Gordon, Miles P. "Climate Planning with Multiple Knowledge Systems: The Case of Tribal Adaptation Plans." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou152475789156055.
Повний текст джерела
4
Hou, Huiyi, and 侯慧仪. "Marine biofouling organisms respond to multiple stressors in a changing climate." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194551.
Повний текст джерелаАнотація:
The marine environment is likely to experience profound climate change in the coming 100 years and beyond. Ocean acidification (OA) is one of the climate change issues attracting the attention of researchers all over the world. The decreasing pH of the oceans might threaten marine biofouling organisms. However, climate change is not only involved with ocean acidification (OA) but the change of other environmental variables, such as temperature and salinity. These environmental factors act as multiple stressors and synergistically affect shell-forming biofoulers, in which, the calcium carbonate skeleton structure plays an important role of protection. Previous studies regarding the response of marine biofoulers to the environmental stressors were generally summarized in this article. Then a calcifying biofouling tube worm, Hydroides elegans, were reared from larval stage to early juvenile stage under control and treatment conditions to examine the combined effects of temperature (24, 30°C), pH (8.1, 7.7) and salinity (34, 27ppt). Juvenile growth and chemical composition (Mg/Ca and Sr/Ca) of their calcareous tubes were tested and used as assessment of effects of the three environmental stressors. The experiment revealed that H. elegans was robust to the environmental change because juvenile development positively responded to temperature and the interaction between temperature and salinity. Other combinations did not exert significant effect. The results suggest the need of further study of proteomics and transcriptomics to reveal the mechanisms of calcification as well as long-term studies to examine the energy costs of adaptation. In addition, the non-significant chemical composition (Mg/Ca and Sr/Ca) of the tube of this organism suggest a need of further exploration of the same animal but not only focus on three factors but the seawater chemical composition as well.published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management
5
Tong, Fan. "Capacity demand and climate in Ekerö : Development of tool to predict capacity demand underuncertainty of climate effects." Thesis, KTH, Elektroteknisk teori och konstruktion, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-152522.
Повний текст джерелаАнотація:
The load forecasting has become an important role in the operation of power system, and several models by using different techniques have been applied to solve these problems. In the literature, the linear regression models are considered as a traditional approach to predict power consumption, and more recently, the artificial neural network (ANN) models have received more attention for a great number of successful and practical applications. This report introduces both linear regression and ANN models to predict the power consumption for Fortum in Ekerö. The characteristics of power consumption of different kinds of consumers are analyzed, together with the effects of weather parameters to power consumption. Further, based on the gained information, the numerical models of load forecasting are built and tested by the historical data. The predictions of power consumption are focus on three cases separately: total power consumption in one year, daily peak power consumption during winter and hourly power consumption. The processes of development of the models will be described, such as the choice of the variables, the transformations of the variables, the structure of the models and the training cases of ANN model. In addition, two linear regression models will be built according to the number of input variables. They are simple linear regression with one input variable and multiple linear regression with several input variables. Comparison between the linear regression and ANN models will be carried out. In the end, it finds out that the linear regression obtains better results for all the cases in Ekerö. Especially, the simple linear regression outperforms in prediction of total power consumption in one year, and the multiple linear regression is better in prediction of daily peak load during the winter.
6
Star, Jonathan, Erika L. Rowland, Mary E. Black, Carolyn A. F. Enquist, Gregg Garfin, Catherine Hawkins Hoffman, Holly Hartmann, Katharine L. Jacobs, Richard H. Moss, and Anne M. Waple. "Supporting adaptation decisions through scenario planning: Enabling the effective use of multiple methods." ELSEVIER SCIENCE BV, 2016. http://hdl.handle.net/10150/622731.
Повний текст джерелаАнотація:
Scenario planning is a technique used to inform decision-making under uncertainty, and is increasingly applied in the field of climate change adaptation and policy. This paper describes applications that combine previously distinct scenario methods in new and innovative ways. It draws on numerous recent independent case studies to illustrate emerging practices, such as far stronger connections between researcher-driven and participatory approaches and cycling between exploratory and normative perspectives. The paper concludes with a call for greater support for, and collaboration among, practitioners with the argument that mixed methods are most effective for decision-making in the context of climate change challenges.
7
Dusselier, Hallie E. "Understanding 20th Century Antarctic Pressure Variability and Change in Multiple Climate Model Simulations." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1469189473.
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8
Thompson, William F. "Parametrization and multiple time scale problems with non-Gaussian statistics related to climate dynamics." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54557.
Повний текст джерелаАнотація:
Many problems in climate modelling are characterized by their chaotic nature and multiple time scales. Stochastic parametrization methods can often simplify the analysis of such problems by using appropriate stochastic processes to account for degrees of freedom that are impractical to model explicitly, such that the statistical features of the reduced stochastic model are consistent with more complicated models and/or observational data. However, applying appropriate stochastic parametrizations is generally a non-trivial task. This is especially true when the statistics of the approximated processes exhibit non-Gaussian features, like a non-zero skewness or infinite variance. Such features are common in problems with nonlinear dynamics, anomalous diffusion processes, and multiple time scales. Two common topics in stochastic parameterization are model parameter estimation and the derivation of reduced stochastic models. In this dissertation, we study both of these topics in the context of stochastic differential equation models, which are the preferred formalism for continuous-time modelling problems. The motivation for this analysis is given by problems in atmospheric or climate modelling. In Chapter 2, we estimate parameters of a dynamical model of sea surface vector winds using a method based on the properties of differential operators associated with the probabilistic evolution of the wind model. The parameter fields we obtain allow us to reproduce statistics of the vector wind data and inform us regarding the limitations of both the estimation method and the model itself. In Chapter 3, we derive reduced stochastic models for a class of dynamical models with multiple time scales that are driven by α-stable stochastic forcing. The results of Chapter 3 are applied in Chapter 4, where we derive a similar approximation for processes that are driven by a fast linear process experiencing additive and multiplicative Gaussian white noise forcing. The results of these chapters complement previous results for systems driven by Gaussian white noise and suggest a possible dynamical mechanism for the appearance of α-stable stochastic forcing in some climatic time series.Science, Faculty of
Mathematics, Department of
Graduate
9
Gooding, Rebecca Ann. "Multiple abiotic changes and species interactions mediate responses to climate change on rocky shores." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45550.
Повний текст джерелаАнотація:
Anthropogenic climate change poses a serious threat to biodiversity. Accurate predictions of the ecological consequences of future abiotic change will require a broad perspective that takes into account multiple climate variables, species-specific responses, and intra- and interspecific dynamics. I addressed these issues in the context of a marine rocky intertidal community to determine how abiotic and biotic factors can mediate the effects of climate change. I began with two studies on the organismal-level effects of multiple abiotic variables. In the first study, I found that acute exposure to low salinity reduced the survival of littorine snails facing thermal stress, but that ocean acidification (OA) had no such effect. In a second study, I showed that sustained exposure to increased temperature and OA had positive and additive effects on the growth and feeding of the purple ochre sea star. These findings demonstrate that studies of multiple climate variables will be important not only to identify additive and non-additive effects, but also to determine which climate variables will be detrimental for a given species. Next, I measured how species-specific responses to climate change can alter species interactions. By quantifying the effects of body size on the feeding behaviours of sea stars preying on mussels, I demonstrated that climate-driven changes in body size can have profound impacts on the strength of this interaction. Finally, I investigated how population-level responses to multiple abiotic variables can be affected by the presence of an interacting species. I built a predator-prey model that simulates the ecologically important interaction between the purple ochre sea star and its preferred prey, mussels. Using empirical estimates of sea star and mussel responses to increased temperature and OA, I simulated their interaction under various climate scenarios. I found that predation exacerbated the effects of climate change on mussel populations, and that climate change increased the strength of the sea star-mussel interaction. My work demonstrates that the effects of climate change will likely be mediated by a combination of biotic and abiotic factors, and that these factors should be considered when making predictions about the ecological consequences of climate change.
10
Rose, Brian E. J. (Brian Edward James). "Oceanic control of the sea ice edge and multiple equilibria in the climate system." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62496.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 215-227).
I study fundamental mechanisms of atmosphere-ocean-sea ice interaction. Hierarchies of idealized models are invoked to argue that multiple equilibria and abrupt change are robust features of the climate system. The main finding is that meridional structure in poleward oceanic energy transport, which is set by the wind forcing, gives rise to preferred latitudes for the sea ice edge, including a stable large ice cap extending into mid-latitudes. I review multiple equilibria in energy balance models (EBMs), and extend the EBM to include explicit ocean heat transport (OHT) and insulating sea ice. I derive a method for simultaneously satisfying global energy and angular momentum budgets through a diffusive closure for potential vorticity, enabling a prediction of the basic shape of the surface wind stress. An idealized model of wind-driven gyres links this stress to OHT, and gives significant structure on sub-hemispheric scales in agreement with observations. This model predicts a stable large ice cap solution not found in the classic EBM, made possible by convergence of OHT in mid-latitudes. Analogous multiple equilibria are found in coupled atmosphere-ocean-sea ice general circulation model (GCM) simulations with idealized geometry (a pure aquaplanet and a "ridgeworld" with a global-scale ocean basin). Despite differing ocean dynamics, both configurations support similar equilibria: an ice-free climate, a cold climate with mid-latitude sea ice edge, and a completely ice-covered Snowball state. Multiple states persist despite a seasonal cycle and vigorous internal variability. Simulations with slowly-evolving thermal forcing show that some transitions between the ice-free and large ice cap states are abrupt. Multiple equilibria are explored in uncoupled simulations with prescribed OHT. The large ice cap is stabilized by wind-driven convergence of OHT at the poleward edge of the subtropical thermocline. The size of the large ice cap is sensitive to the meridional and seasonal distribution of OHT convergence. The ice-free state persists in the absence of high-latitude OHT. Mid-latitude convergence of OHT warms the poles by driving increased atmospheric heat transport to the poles. This effect is captured in a simple diffusive EBM. I discuss the significance of these findings for understanding the paleoclimate record.
by Brian E. J. Rose.
Ph.D.
11
Liu, Chao. "Variations of Global Ocean Salinity from Multiple Gridded Argo Products." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7848.
Повний текст джерелаАнотація:
Salinity is one of the fundamental ocean state variables. Variations of ocean salinity can be used to infer changes in the global water cycle and air-sea freshwater exchange. Many institutions have developed gridded Argo products of global coverage. However, the existing gridded salinity products have not yet been dedicatedly intercompare and assessed. In this study, the mean state, annual and interannual variabilities, and decadal changes of ocean salinity from five Argo-based gridded salinity products, available from UK Met Office, JAMSTEC, Scripps Institution of Oceanography, China Second Institute of Oceanography, and International Pacific Research Center, are examined and compared for their overlapping period of 2005-2015 within two depth intervals (0-700 m and 700-2000 m), as well as the sea surface. Though some global and regional features are relatively reproducible, obvious discrepancies are found particularly for the deeper layer. These discrepancies are not apparent on the 11-year climatological mean or the trend patterns, but are readily evident on temporal variations. For instance, the potentially undersampled current systems in the North Atlantic and Southern Ocean are one of the main reasons for the observed discrepancies. The gridded products from Scripps, JAMSTEC and Met Office show large deviation from the ensemble mean, particularly in regions like the Atlantic Ocean and the tropical Pacific. Large disagreements are found in the first and final years, which can lead to different estimates on decadal trends. This study can serve as a useful reference on how to utilize and improve the existing gridded salinity products.
12
Somor, Andrew. "Quantifying streamflow change following bark beetle outbreak in multiple central Colorado catchments." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/193435.
Повний текст джерелаАнотація:
Over the last decade, millions of acres of western North American forest have been reduced to areas of standing dead trees following eruptions in bark beetle populations. This thesis provides up-to-date information on streamflow response to the recent bark beetle outbreak in subalpine forests of the Colorado Rockies. Streamflow and climate measures are evaluated in eight central Colorado catchments with long-term data records and varying levels of beetle outbreak. No detectable streamflow change is observed in 7 of 8 highly impacted catchments. A significant reduction in streamflow is observed in 1 highly impacted catchment and is likely driven by tree mortality and record warm temperatures. These findings deviate from expected results and have important implications for vegetation and streamflow change under a warmer climate.
13
Carrillo, Cruz Carlos Mauricio. "North American monsoon variability from paleoclimate era to climate change projection| A multiple dataset perspective." Thesis, The University of Arizona, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3667939.
Повний текст джерелаАнотація:
In southwestern United States, the North American monsoon (NAM) is the main driver of severe weather in the Southwest. How the monsoon has behaved in the past and how it will change in the future is a question of importance for natural resource management and infrastructural planning. In this dissertation, I present the results of three studies that have investigated NAM variability and change from the perspective of paleoclimate records, future climate change projections, and simulation of the low-frequency variability with the longest retrospective atmospheric reanalysis.
In the first study, a monsoon-sensitive network of tree-ring chronologies is evaluated within its ability to reproduce NAM variability during the past four centuries. The tree-ring chronologies can reasonable characterizes the dominant modes of NAM climate variability and reveal low-frequency climate variability at decadal and longer timescales that is beyond the ability of the instrumental record to temporally well resolve. This low-frequency climate variability seems to coincide with the occurrence of multiyear persistent droughts.
In the second study, we consider the modes of climate variability to assess the degree of physical uncertainty in climate change projections models used in the North American Regional Climate Change Assessment Program (NARCCAP). NARCCAP models are evaluated mainly on their ability to represent warm season driven by quasi-stationary Rossby wave trains and El Niño Southern Oscillation – Pacific Decadal Variability (ENSO-PDV). Only one out of eight NARCCAP models has a reasonable representation of the seasonal cycle of monsoon precipitation and ENSO-driven variability in both the 20 th and 21st centuries. No decadal variability was observed in any of the NARCCAP models.
In the third study, the low-frequency drought signal found with tree-ring chronologies is further explored within the framework of a regional climate modeling. The Twentieth-Century Reanalysis is dynamically downscaled (DD-20CR) and its statistic analysis suggests that low-frequency drought signal in the Southwest is driven by atmospheric circulation changes on global to continental scales that affect precipitation in Central American as well. Low-frequency climate variability is therefore likely responsible for the multiyear persistent droughts in the last four centuries, as independently evaluated from the tree-ring monsoon-sensitive network.
14
Carrillo, Cruz Carlos Mauricio. "North American Monsoon Variability from Paleoclimate Era to Climate Change Projection: A Multiple Dataset Perspective." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/338900.
Повний текст джерелаАнотація:
In the southwestern United States, the North American monsoon (NAM) is the main driver of severe weather and accounts for nearly half the annual precipitation. How the monsoon has behaved in the past and how it will change in the future is a question of major importance for natural resource management and infrastructural planning. In this dissertation, I present the results of three studies that have investigated North American monsoon variability and change from the perspective of paleoclimate records, future climate change projections, and simulation of the low-frequency variability with the longest retrospective atmospheric reanalysis. In the first study, a monsoon-sensitive network of tree-ring chronologies is evaluated within its ability to reproduce NAM variability during the past four centuries. Matrix methods are used to detect the low-frequency spatiotemporal variability. The treering chronologies can reasonable characterizes the dominant modes of NAM climate variability. The monsoon tree-ring network is able to reproduce the interannual variability of cool and warm season precipitation, in a manner similar to the period of the instrumental record. Earlywood and latewood adjusted chronologies reveal low frequency climate variability at decadal and longer timescales that is beyond the ability of the instrumental record to temporally well resolve. This low-frequency climate variability seems to be part of a much larger cycle that coincides with the occurrence of multiyear persistent droughts. In the second study, we consider the modes of natural climate variability identified in the previous study to objectively assess the degree of physical uncertainty in climate change projections for NAM from Regional Climate Models (RCMs) used in the North American Regional Climate Change Assessment Program (NARCCAP). Climate change projection models are evaluated mainly on their ability to represent warm season driven by quasi-stationary Rossby wave trains and El Niño Southern Oscillation – Pacific Decadal Variability (ENSO-PDV). It is concluded that use of the NARCCAP model ensemble mean for NAM climate projections is probably not suitable. NARCCAP RCMs are largely a slave to their driving global models and their error in the specification of large-scale atmospheric circulation. Only one out of eight NARCCAP RCMs has a reasonable representation of the seasonal cycle of monsoon precipitation and ENSOdriven interannual variability in both the 20th and 21st centuries. No decadal variability was observed in any of the NARCCAP RCMs. In the third study, the low-frequency drought signal found with tree-ring chronologies is further explored within the framework of a regional climate modeling. Version 2 of the Twentieth-Century Reanalysis (DD-20CR) is dynamically downscaled over a contiguous U.S.-Mexico domain. Statistic analysis of the DD-20CR suggests that the low-frequency drought signal in the Southwest is driven by atmospheric circulation changes on global to continental scales that affect precipitation in Central American as well. DD-20CR reproduces the spatial patterns of precipitation associated with climate variability at decadal and longer timescales in a manner that compares well with observational records and tree-ring chronologies. Low-frequency climate variability is therefore likely responsible for the multiyear persistent droughts in the last four centuries, as independently evaluated from the tree-ring monsoon-sensitive network.
15
Rova, Silvia <1987>. "Analysis and management of multiple ecosystem services in social-ecological systems under a changing climate." Doctoral thesis, Università Ca' Foscari Venezia, 2018. http://hdl.handle.net/10579/14955.
Повний текст джерелаАнотація:
This thesis aims to develop new methods for the analysis and management of multiple ecosystem services (ES) in the context of climate change. Taking the Venice lagoon (Italy) as case study, it focuses on two major research challenges in the ES field of study, that are, understanding how multiple ES are co-produced and interact, and how they can be managed sustainably. These challenges are addressed first through a conceptual viewpoint based on the social-ecological systems framework, which distinguishes between ES with “direct” and “mediated” flow type: the first occur directly through some ecological functions, whereas the second require the involvement of human activities, which can generate feedbacks on the same and/or other ES. This viewpoint is then translated into a dynamic ES model, which represents multiple ES together as a single network, accounting for their interactions and for the effects of drivers of change. This represents a significant step forward with respect to current ES models, which provide static snapshots of single ES. The modeling results highlight the importance of including the ES interactions, the absence of which remarkably affects the results. Finally, the modeling application is merged with a quantitative mapping of the multiple ES delivered by the Venice lagoon, aiming at analyzing the sustainability of the ES patterns. This analysis allows to delineate management trajectories for correcting the unsustainable ES patterns and preserving the ES delivery in the face of climate change. The joint analysis of multiple ES and their interactions, along with a sustainability-driven interpretation, seems crucial for the application of ES to management challenges in the context of climate change.
16
Carr, Sam. "An examination of multiple goals in children's physical education : motivational correlates of goal profiles and the role of perceived climate in multiple goal development." Thesis, Lancaster University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436739.
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17
Berner, Nadine [Verfasser], and Matthias [Akademischer Betreuer] Holschneider. "Deciphering multiple changes in complex climate time series using Bayesian inference / Nadine Berner ; Betreuer: Matthias Holschneider." Potsdam : Universität Potsdam, 2016. http://d-nb.info/1219514179/34.
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18
Garris, Heath William. "Restructuring of Wetland Communities in Response to a Changing Climate at Multiple Spatial and Taxonomic Scales." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1383312022.
Повний текст джерела
19
Spiegel, Rachel Hannah. "Drowning in Rising Seas: Navigating Multiple Knowledge Systems and Responding to Climate Change in the Maldives." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/pitzer_theses/76.
Повний текст джерелаАнотація:
The threat of global climate change increasingly influences the actions of human society. As world leaders have negotiated adaptation strategies over the past couple of decades, a certain discourse has emerged that privileges Western conceptions of environmental degradation. I argue that this framing of climate change inhibits the successful implementation of adaptation strategies. This thesis focuses on a case study of the Maldives, an island nation deemed one of the most vulnerable locations to the impacts of rising sea levels. I apply a postcolonial theoretical framework to examine how differing knowledge systems can both complement and contradict one another. By analyzing government-enforced relocation policies in the Maldives, I find that points of contradiction between Western and indigenous environmental epistemologies can create opportunities to bridge the gap between isolated viewpoints and serve as moments to resist the dominant climate change discourse.
20
Pucko, Carolyn Ann. "The Impacts of Multiple Anthropogenic Disturbances on the Montane Forests of the Green Mountains, Vermont, USA." ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/315.
Повний текст джерелаАнотація:
How and why species’ ranges shift has long been a focus of ecology but is now becoming increasingly important given the current rate of climatic and environmental change. In response to global warming, species will need to migrate northward or upward to stay within their climatic tolerances. The ability of species to migrate will determine their fate and affect the community compositions of the future. However, to more accurately predict the future extent of species, we must identify and understand their responses to past and current climatic and environmental changes. The first place change is expected to occur is within ecotones where the ranges of many species converge and individuals exist at the limits of their environmental tolerances. In montane regions, these boundaries are compressed, creating a situation in which even relatively small changes in conditions can lead to shifts in the elevational ranges of species.
In this dissertation, I examine the responses of forests in the Green Mountains of Vermont to recent climatic and environmental change in an attempt to understand how future climate change will affect their location and composition. I focus on the Boreal-Deciduous Ecotone (BDE), where the high elevation spruce-fir forests converge with the lower elevation northern hardwoods. In addition to investigating adult trees within the BDE, I also examine the responses of understory herbs and tree seedlings to changes in environmental and climatic factors. Factors considered in these investigations include temperature, soil environment, light environment, invasive species, competition, disturbance and many others. I will examine the complex range of responses in forest species that results from prolonged exposure to these forces alone and in combination.
I have attempted to identify the responses of forest species to environmental changes by resurveying historic vegetation plots (Chapter 2), experimentally manipulating the growing environment of tree seedlings (Chapter 3) and performing dendrochronological analyses on tree rings (Chapter 4). Through my resurvey of historic vegetation plots, I determined the degree to which understory species have shifted as individuals or as groups. I also identified a set of novel understory communities that have developed since the 1960's in response to recent climate change, acid deposition and invasive species (Chapter 2). By transplanting and artificially warming tree seedlings, I identified factors responsible for limiting the growth and survival of northern hardwood species above the BDE. Temperature was the primary factor limiting sugar maple (Acer saccharum) at high elevations, while yellow birch (Betula alleghaniensis) was limited almost exclusively by light (Chapter 3). Dendrochronological studies of sugar maples indicated that prolonged exposure to acidified soils has only recently caused growth declines and has altered their relationship to climate (Chapter 4). Together, these studies have produced a cohesive picture of how northeastern montane forests have responded to recent climate change and other anthropogenic impacts. These findings can be used to help predict future species' ranges and identify species that may not be capable of migrating fast enough on their own to keep pace with changes in climatic conditions.
21
Glaser, Sofia. "The Corona pandemic - a focusing event for insufficient governmental action on climate change mitigation?" Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-413203.
Повний текст джерелаАнотація:
This study seeks to examine whether the Corona pandemic has potential to serve as a focusing event for the problem of insufficient governmental action on climate change mitigation. The study is built on the Multiple Streams Framework by John W. Kingdon, with a main focus on the focusing event theory. According to this, focusing events can come in three forms: as crises and disasters, personal experiences of policymakers, and as symbols. Kingdon’s theoretical discussions, alongside my own developments of his work, provides the basis for a set of analytical questions through which the answer to the research question is provided. The analysis reveals that while the pandemic indeed can be considered a crisis or disaster and personal experiences of policymakers, establishing whether these could focus attention to the specific problem of insufficient governmental action on climate change mitigation requires further research, as the perceived cause of the crisis or disaster and personal experience must be established. However, the paper finds that the pandemic indeed has potential to serve as a symbol for the specific insufficient governmental action, for instance by stressing that deforestation increases the risk of zoonotic outbreaks, such as the Corona pandemic.
22
Cradock-Henry, Nicholas Andrew. "Farm-level vulnerability to climate change in the Eastern Bay of Plenty, New Zealand, in the context of multiple stressors." Thesis, University of Canterbury. Geography, 2011. http://hdl.handle.net/10092/6564.
Повний текст джерелаАнотація:
Climate change research is undergoing a monumental shift, from an almost exclusive focus on mitigation, and the reduction of greenhouse gases, to adaptation, and identifying the ways in which nations, communities and sectors might best respond to the reality of a changing climate. Vulnerability assessments are now being employed to identify the conditions to which socio ecological systems are exposed-sensitive and their capacity to adapt. Work has been conducted across a range of geographical locations and systems as diverse as healthcare and mining. There are however, few examples of analyses incorporating an assessment of the multiple climatic and non-climatic stressors to which agricultural producers are exposed.
This thesis examines farm-level vulnerability to climate change of agricultural producers from the Eastern Bay of Plenty, New Zealand. The study area has a diverse agricultural economy, founded upon pastoral farming (dairy and drystock) and kiwifruit. This dependence on agricultural production, and the likely influence of expected changes in climatic conditions in the future provided a unique setting in which to develop a place-based case study exploring vulnerability to future climatic variability and change. Using a mixed methods approach, including semi-structured interviews and temporal analogues, a conceptual framework of farm-level vulnerability was developed and applied. The application of the framework was conducted through an empirical study that relied on engagement with and insights from producers who identified current exposure-sensitivity and adaptive capacity. It is shown that pastoral farmers and kiwifruit growers are exposed-sensitive to a range of climatic and non-climatic conditions that affect production, yields and farm income and returns. It demonstrates that producers have in turn, developed a range of short- and long-term adaptive strategies in order to better manage climatic conditions. It shows that these responses are varied, and are not made in response to climatic conditions alone, illustrating the need to consider other, multiple stimuli. An assessment of future vulnerability is presented, based on the empirical work and the identification of those drivers of vulnerability that are likely to be of concern and that will shape the capacity of farmers and growers to respond to climatic variability and change.
The thesis as a whole not only provides a place-based case study on the vulnerability of farmers and kiwifruit growers in eastern New Zealand, but also demonstrates the need to engage with producers in order to develop an understanding of the complex ways in which climatic conditions interact with non-climatic stimuli beyond the farm-gate to influence vulnerability to climatic variability and change, both now and in the future.
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Barnwell, Anna Theodora. "Multiple Measurement of International Regime Effectiveness : Comparative Study of the International Ozone Depletion Regime and Climate Change Regime." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for sosiologi og statsvitenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13059.
Повний текст джерелаАнотація:
The study of international environmental regime effectiveness is contextualized in globalization. In this classificatory and comparative study, the cases of the ozone depletion regime and climate change regime are evaluated for their level of effectiveness. Regime effectiveness is conceptualized in a three-fold indicator operationalization of “output,” “outcome,” and “impact.” This multiple-measurement approach to regime effectiveness facilitates a robustness check of the levels of effectiveness of the ozone depletion regime and the climate change regime. The study employs an analytical framework based on the standards of collective optimum and goal attainment. The classification of regime effectiveness through this framework provides nuanced findings for each regime depending on which operationalization of effectiveness is applied. The comparison between the regimes finds that they are similar in terms of the outcome indicator, but vary significantly on the output and impact indicators, with the ozone regime scoring a high level of effectiveness and the climate regime ranking a low level of effectiveness. The findings emphasize areas of institutional design and scientific overlap between the regimes that could be used as a platform for a future explanatory study.
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Manangan, Arie Ponce. "Influenza Prevalence in the US Associated with Climatic Factors, Analyzed at Multiple Spatial and Temporal Scales." unrestricted, 2006. http://etd.gsu.edu/theses/available/etd-06142006-103922/.
Повний текст джерелаАнотація:
Thesis (M.A.)--Georgia State University, 2006.Title from title screen. Susan Walcott, Paul Knapp, committee co-chairs; John Allensworth, committee member. Electronic text (106 p. : col. ill., col. maps) : digital, PDF file. Description based on contents viewed July 9, 2007. Includes bibliographical references (p. 103-106).
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Hallman, Tyler Andrew. "RESPONSES OF HYLA CHRYSOSCELIS TO SUBLETHAL METAL MIXTURES UNDER INCREASING TEMPERATURES: IMPLICATIONS FOR THE EFFECTS OF CLIMATE CHANGE ON AMPHIBIANS." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/934.
Повний текст джерелаАнотація:
Amphibian populations are rapidly declining worldwide. Although individual factors may have large local influences, worldwide declines are attributed to interacting global stressors including rising temperatures and environmental pollutants. Globally, water temperatures closely track rising air temperatures and increase the metabolic rates of aquatic ectotherms, changing the rates of uptake, biotransformation, and excretion of contaminants, such as metals. To test how interactions of multiple, chronic stressors affect amphibian growth, I exposed Cope's gray treefrogs (Hyla chrysoscelis) in an outdoor mesocosm facility to three temperature regimes (ambient, ambient +1.5 oC, ambient +2.5 oC) in filtered lake water amended with mixtures of cadmium, copper, and lead ranging from 3.7 to 26.7 risk quotients (relative to the chronic concentration criteria protective of freshwater organisms). Temperature shifts and sublethal metals concentrations significantly affected the energetics of tadpoles as assessed by non-parametric and parametric analyses. Regression analyses indicated no significant relationship between temperature and time to forelimb emergence at the three lowest metals concentrations, but the relationship was parabolic at the three highest concentrations, indicating a differential effect of temperature across a gradient of water quality. The concept that tadpoles increase developmental rates to escape unfavorable aquatic conditions was supported at each temperature by shortened time to forelimb emergence (Gosner Stage 42) at the second highest metals concentration. This response, however, was overwhelmed by the energetic costs associated with the highest concentration and the highest temperature. Moreover, these parabolic relationships match predictions based on species specific thermal windows and pejus temperatures. My findings indicate that global warming may affect contaminated waters to a greater extent than pristine aquatic ecosystems, and that the primary effect may be diminished pejus and critical thermal maximum temperatures, and a narrowing of the species' thermal window.
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Yu, Zicheng. "Late Quaternary paleoecology of the southern Niagara Escarpment, Ontario, Canada, a multiple proxy investigation of vegetation and climate history." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq28098.pdf.
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Irby, Isaac. "Using Water Quality Models in Management - A Multiple Model Assessment, Analysis of Confidence, and Evaluation of Climate Change Impacts." W&M ScholarWorks, 2017. https://scholarworks.wm.edu/etd/1516639464.
Повний текст джерелаАнотація:
Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea-level, and changes in precipitation, have elevated the conversation surrounding the future of water quality in the Bay. The overall goal of this dissertation project is to use a combination of models and data to better understand and quantify the impact of changes in nutrient loads and climate on water quality in the Chesapeake Bay. This research achieves that goal in three parts.
First, a set of eight water quality models is used to establish a model mean and assess model skill. All models were found to exhibit similar skill in resolving dissolved oxygen concentrations as well as a number of dissolved oxygen-influencing variables (temperature, salinity, stratification, chlorophyll and nitrate) and the model mean exhibited the highest individual skill. The location of stratification within the water column was found to be a limiting factor in the models’ ability to adequately simulate habitat compression resulting from low-oxygen conditions.
Second, two of the previous models underwent the regulatory Chesapeake Bay pollution diet mandated by the Environmental Protection Agency. Both models exhibited a similar relative improvement in dissolved oxygen concentrations as a result of the reduction of nutrients stipulated in the pollution diet. A Confidence Index was developed to identify the locations of the Bay where the models are in agreement and disagreement regarding the impacts of the pollution diet. The models were least certain in the deep part of the upper main stem of the Bay and the uncertainty primarily stemmed from the post-processing methodology.
Finally, by projecting the impacts of climate change in 2050 on the Bay, the potential success of the pollution diet in light of future projections for air temperature, sea level, and precipitation was examined. While a changing climate will reduce the ability of the nutrient reduction to improve oxygen concentrations, that effect is trumped by the improvements in dissolved oxygen stemming from the pollution diet itself. However, climate change still has the potential to cause the current level of nutrient reduction to be inadequate. This is primarily due to the fact that low-oxygen conditions are predicted to start one week earlier, on average, in the future, with the primary changes resulting from the increase in temperature.
Overall, this research lends an increased degree of confidence in the water quality modeling of the potential impact of the Chesapeake Bay pollution diet. This research also establishes the efficacy of utilizing a multiple model approach to examining projected changes in water quality while establishing that the pollution diet trumps the impact from climate change. This work will lead directly to advances in scientific understanding of the response of water quality, ecosystem health, and ecological resilience to the impacts of nutrient reduction and climate change.
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Brunetta, Fabiana. "Social Dominance Orientation and Emotion Regulation: A Parallel Multiple Mediator Model of Instigated Incivility Moderated By Workgroup Civility Climate." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3907.
Повний текст джерелаАнотація:
While most of the existing research on the topic of workplace incivility has focused upon its consequences on employee and organizational well-being, researchers are recognizing the need for research on predictors, mediators, and moderators of uncivil workplace behavior. The current study contributes to this new wave of workplace incivility research by emphasizing the links among variables not previously explored in incivility research. This nonexperimental correlational study (N = 1027) developed and tested a parallel multiple mediator model of instigated incivility. The model examined the mediation of the emotion regulation strategies – cognitive reappraisal and expressive suppression – on the relation of two types of social dominance orientation – intergroup dominance (SDO-D) and intergroup antiegalitarianism (SDO-E) – on the outcome of instigated incivility, and tested the moderating effects of workgroup civility climate on the paths of the proposed model.
An Internet-based self-report survey battery was administered to a sample drawn from Amazon’s Mechanical Turk worker population. Hypotheses were tested though structural equation modeling analytic procedures. Findings suggest that intergroup dominance (SDO-D) increases instigated incivility and the relationship is not moderated by workgroup civility climate norms. In contrast, intergroup antiegalitarianism (SDO-E) decreases instigated incivility. Further, this study found that SDO-D had an indirect effect on instigated incivility through the emotion regulation strategy of expressive suppression. Additional findings suggest that the emotion regulation strategy of cognitive reappraisal has the potential to reduce uncivil workplace behavior. Future research was proposed to test the model examined in this study in different cultural settings, with additional mediators and moderators, and longitudinally. The practical findings suggest that HRD practitioners may find emotion regulation and civility trainings useful to reduce the likelihood of uncivil workplace behavior.
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Ngigi, Marther [Verfasser]. "Managing Risk under Climate Change in Rural Kenya : Multiple Shocks, Poverty, Gender, and Potential for Group-Based Approaches / Marther Ngigi." Bonn : Universitäts- und Landesbibliothek Bonn, 2017. http://d-nb.info/1140586440/34.
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Watson, Stephen C. L. "The impact of multiple stressors on coastal biodiversity and associated ecosystem services." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/16817.
Повний текст джерелаАнотація:
Marine and coastal ecosystems are subject to diverse and increasingly intensive anthropogenic activities, making understanding cumulative effects critically important. However, accurately accounting for the cumulative effects of human impacts can be difficult, with the possibility of multiple stressors interacting and having greater impacts than expected, compounding direct and indirect effects on individuals, populations, communities and ecosystems. Assessment of multiple stressors therefore requires extensive scientific research that directly tests how single or multiple ecological components are affected by stressors, both singly and when combined, and as a consequence, cumulative effects assessments are now increasingly included in environmental assessments. Currently, there is a need to assess these at larger spatial scales, with additional research also urgently needed on the responses of ecological components, processes and functions to single and cumulative stressors. As cumulative environmental impacts could be better addressed by regional stressor effects assessments that combine methods for predicting multiple pressures on ecosystem recovery alongside degradation, this study used several separate approaches that can be used in parallel to give support for local management measures. I tested four completely different methods - a range of multi-metric indices, a food web model (Ecopath), a predictive model (Ecosim) and a Bayesian Belief Network model. Each approach was tested and compared in two shallow water estuarine systems, in Scotland and England, initially concerning the impact of nutrient enrichment and subsequent recovery and was followed by an investigation of how the addition of multiple stressors (nutrient levels, temperature and river-flow rates) would impact the future state of each system. The response to stressors was highly context dependent, varying between and within geographic locations. Overall, each of the four different approaches complemented each other and gave strong support for the need to make big reductions in the pressures and to consider trade-offs between impacting pressures. The models and tools also indicate that in order to reach an improved overall environmental state of each ecosystem, a focus on nutrient reductions are likely to be the most effective of the controls on stressors explored and that cumulative effects of the management of nutrient inputs and increased water temperatures and river-flow are likely to exist.
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Niiranen, Susa. "Multiple forces drive the Baltic Sea food web dynamics and its response to environmental change." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-92541.
Повний текст джерелаАнотація:
Understanding the interaction of multiple drivers and their compounded effects on ecosystem dynamics is a key challenge for marine resource management. The Baltic Sea is one of the world’s seas most strongly impacted by effects from both human activities and climate. In the late 1980’s changes in climate in combination with intensive fishing initiated a reorganization of the Central Baltic Sea (CBS) food web resulting in the current sprat-dominated state. In the future, climate change is projected to cause drastic changes in hydrodynamic conditions of the world oceans in general, and the Baltic Sea in particular. In this thesis, CBS food web responses to the combined effects of fishing, nutrient loads and climate were tested for the past (1974-2006) and projected into the future (2010-2098). A new food web model for the CBS (BaltProWeb) was developed using extensive monitoring data across trophic levels. This model described the past food web dynamics well, and was hence also used for future (2010-2098) projections. Different ensemble modeling approaches were employed when testing the food web response to future scenarios. The results show that regardless the climate change, the management of nutrient loads and cod fishing are likely to determine the food web dynamics and trophic control mechanisms in the future Baltic Sea. Consequently, the variation in the food web projections was large, ranging from a strongly eutrophied and sprat-dominated to a cod-dominated CBS with eutrophication levels close to today’s values. The results also suggest a potential risk of abrupt ecosystem changes in the future CBS, particularly if the nutrient loads are not reduced. Finally, the studies illustrate the usefulness of the ensemble modeling approach, both from the perspective of ecosystem-based management as well as for studying the importance of different mechanisms in the ecosystem response.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: In press. Paper 5: Submitted.
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Lee, Ji Yun. "Risk-informed decision for civil infrastructure exposed to natural hazards: sharing risk across multiple generations." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53965.
Повний текст джерелаАнотація:
Civil infrastructure facilities play a central role in the economic, social and political health of modern society and their safety, integrity and functionality must be maintained at manageable cost over their service lives through design and periodic maintenance. Hurricanes and tropical cyclones, tornadoes, earthquakes and floods are paramount among the potentially devastating and costly natural disasters impacting civil infrastructure. Even larger losses may occur in the future, given the population growth and economic development accompanying urbanization in potentially hazardous areas of the world. Moreover, in recent years, the effects that global climate change might have on both the frequency and severity of extreme events from natural hazards and their effect on civil infrastructure facilities have become a major concern for decision makers. Potential influences of climate change on civil infrastructure are even greater for certain facilities with service periods of 100 years or more, which are substantially longer than those previously considered in life-cycle engineering and may extend across multiple generations. Customary risk-informed decision frameworks may not be applicable to such long-term event horizons, because they tend to devalue the importance of current decisions for future generations, causing an ethical and moral dilemma for current decision-makers. Thus, intergenerational risk-informed decision frameworks that consider facility performance over service periods well in excess of 100 years and extend across multiple generations must be developed.
This dissertation addresses risk-informed decision-making for civil infrastructure exposed to natural hazards, with a particular focus on the equitable transfer of risk across multiple generations. Risk-informed decision tools applied to extended service periods require careful modifications to current life-cycle engineering analysis methods to account for values and decision preferences of both current and future generations and to achieve decisions that will be sustainable in the long term. The methodology for supporting equitable and socio-economical sustainable decisions regarding long-term public safety incorporates two essential ingredients of such decisions: global climate change effect on stochastic models of extreme events from natural hazards and intergenerational discounting methods for equitable risk-sharing. Several specific civil infrastructure applications are investigated: a levee situated in a flood-prone city; an existing dam built in a strong earthquake-prone area; and a special moment resisting steel frame building designed to withstand hurricanes in Miami, FL. These investigations have led to the conclusion that risks can and should be shared across multiple generations; that the proposed intergenerational decision methods can achieve goals of intergenerational equity and sustainability in engineering decision-making that are reflective of the welfare and aspirations of both current and future generations; and that intergenerational equity can be achieved at reasonable cost.
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Tahmasebi, Asghar [Verfasser]. "Pastoralism under Pressure : Vulnerability of Pastoral Nomads to Multiple Socio-political and Climate Stresses ; The Shahsevan of Northwest Iran / Asghar Tahmasebi." Bonn : Universitäts- und Landesbibliothek Bonn, 2012. http://d-nb.info/1044081457/34.
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Violetti, Daniele <1965>. "Climate change and the tourism sector: the clean development mechanism, a market instrument under the Kyoto Protocol to achieve multiple objectives." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2567/1/Violetti_Daniele_tesi.pdf.
Повний текст джерелаАнотація:
The main objective of this research is to demonstrate that the Clean Development Mechanism (CDM), an instrument created under a global international treaty, can achieve multiple objectives beyond those for which it has been established. As such, while being already a powerful tool to contribute to the global fight against climate change, the CDM can also be successful if applied to different sectors not contemplated before. In particular, this research aimed at demonstrating that a wider utilization of the CDM in the tourism sector can represent an innovative way to foster sustainable tourism and generate additional benefits.
The CDM was created by Article 12 of the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC) and represents an innovative tool to reduce greenhouse gases emissions through the implementation of mitigation activities in developing countries which generate certified emission reductions (CERs), each of them equivalent to one ton of CO2 not emitted in the atmosphere. These credits can be used for compliance reasons by industrialized countries in achieving their reduction targets.
The logic path of this research begins with an analysis of the scientific evidences of climate change and its impacts on different economic sectors including tourism and it continues with a focus on the linkages between climate and the tourism sector. Then, it analyses the international responses to the issue of climate change and the peculiar activities in the international arena addressing climate change and the tourism sector. The concluding part of the work presents the objectives and achievements of the CDM and its links to the tourism sector by considering case studies of existing projects which demonstrate that the underlying question can be positively answered. New opportunities for the tourism sector are available.
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Violetti, Daniele <1965>. "Climate change and the tourism sector: the clean development mechanism, a market instrument under the Kyoto Protocol to achieve multiple objectives." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2567/.
Повний текст джерелаАнотація:
The main objective of this research is to demonstrate that the Clean Development Mechanism (CDM), an instrument created under a global international treaty, can achieve multiple objectives beyond those for which it has been established. As such, while being already a powerful tool to contribute to the global fight against climate change, the CDM can also be successful if applied to different sectors not contemplated before. In particular, this research aimed at demonstrating that a wider utilization of the CDM in the tourism sector can represent an innovative way to foster sustainable tourism and generate additional benefits.
The CDM was created by Article 12 of the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC) and represents an innovative tool to reduce greenhouse gases emissions through the implementation of mitigation activities in developing countries which generate certified emission reductions (CERs), each of them equivalent to one ton of CO2 not emitted in the atmosphere. These credits can be used for compliance reasons by industrialized countries in achieving their reduction targets.
The logic path of this research begins with an analysis of the scientific evidences of climate change and its impacts on different economic sectors including tourism and it continues with a focus on the linkages between climate and the tourism sector. Then, it analyses the international responses to the issue of climate change and the peculiar activities in the international arena addressing climate change and the tourism sector. The concluding part of the work presents the objectives and achievements of the CDM and its links to the tourism sector by considering case studies of existing projects which demonstrate that the underlying question can be positively answered. New opportunities for the tourism sector are available.
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Paull, David James Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "Habitat fragmentation and the southern brown bandicoot Isoodon obesulus at multiple spatial scales." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2003. http://handle.unsw.edu.au/1959.4/38698.
Повний текст джерелаАнотація:
This thesis investigates the process of habitat fragmentation and the spatial and temporal scales at which it occurs. Fragmentation has become an important topic in biogeography and conservation biology because of the impacts it has upon species??? distributions and biodiversity. Various definitions of fragmentation are available but in this research it is considered to be the disruption of continuity, either natural or human-induced in its origins and operative at multiple spatial scales. Using the distribution of the southern brown bandicoot Isoodon obesulus as a case study, three spatial scales of fragmentation were analysed. At the continental scale, the Australian distribution of the subspecies I. o. obesulus was examined in relation to climate, geology and vegetation cover at the time of European settlement of Australia and two centuries later. Using archived wildlife records and Geographic Information Systems (GIS) analyses, habitat suitability models were created to assess natural and human-induced fragmentation of the distribution of I. obesulus in 1788 and 1988. At the regional scale, a study was made of the distribution of I. obesulus in the south-east of the State of South Australia. Again, natural and human-induced patterns of habitat fragmentation were modelled using GIS with climate, soil and vegetation data for the time of European settlement and at present. At the local scale, the distribution of I. obesulus was the subject of a detailed field survey of 372 sites within 29 remnant patches of native vegetation in south-eastern South Australia in order to understand the variables that cause habitat fragmentation. Geographic information systems were used again but in a different way to carefully stratify the field survey by overlaying maps of topography, vegetation and past fires. The large dataset collected from the surveys was described using six generalized linear models which identified the significant variables that fragment the distribution of I. obesulus at a local scale. From the results of the field surveys, a subset of four remnants was chosen for further GIS spatial modelling of the probability of I. obesulus occurring within remnants in response to fire via a controlled burning programme put in place to reduce accumulating fuel loads. These investigations show that habitat fragmentation can be caused by different factors at different spatial scales. At the continental scale, it was found that climate played a dominant role in influencing the fragmented distribution of I. obesulus but vegetation change during the past two centuries has also had a profound impact on the availability of habitat. Within south-eastern South Australia, the species??? regional scale distribution is constrained by climate and also by soil and vegetation patterns. Dramatic change to its regional distribution occurred in the 20th century as a result of the clearance of native vegetation for planting pastures, crops and pines. Fragmentation at the regional scale has resulted in the remaining habitat being reduced to small, isolated, remnant patches of native vegetation. At the local scale it was found that variables which disrupt the continuity of I. obesulus habitat within remnants include vegetation cover in the 0-1 m stratum, abundance of Xanthorrhoea australis and soil texture. For a subset of sites located in one landsystem of the study area, named Young, the age of vegetation since it was last burnt was also found to be a significant variable, with vegetation 10-14 years old since burning providing the most suitable habitat. Spatial modelling of two scenarios for prescribed burning over 15 years revealed that the use of fire as a habitat enhancement tool will be complicated and require a detailed understanding of the factors that cause natural fragmentation in the distribution of I. obesulus at the local scale. A further conclusion of the study was that ecological relationships between species and their habitats require careful interpretation of multi-scaled datasets and conservation plans for endangered species ought to be made at multiple spatial scales. Future research directions are identified including the linking of multi-scaled habitat fragmentation models to genetic studies of the species throughout its range.
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NARDI, ALESSANDRO. "Indirect effects of climate changes: role of ocean warming and acidification on the susceptibility to environmental contamination in marine organisms." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245424.
Повний текст джерелаАнотація:
Le crescenti emissioni antropiche di anidride carbonica stanno causando il riscaldamento e l’acidificazione degli oceani, cambiamenti pericolosi per l’integrità degli ecosistemi marini. Questi cambiamenti potrebbero essere particolarmente dannosi per organismi esposti ad altri fattori di stress nell’ambiente marino, come gli alti livelli di contaminazione antropica nelle aree costiere: le future variazioni di temperatura e pH potranno influenzare la speciazione chimica dei contaminanti inorganici, la loro biodisponibilità, il bioaccumulo e gli effetti biologici negli organismi marini. Nonostante il crescente interesse della comunità scientifica, i possibili effetti delle interazioni di questi fattori di stress sono ancora poco conosciuti. Il principale obiettivo di questa attività di ricerca è stato quello di investigare gli effetti del concomitante aumento di temperatura e diminuzione di pH sul bioaccumulo di cadmio, scelto come contaminante inorganico modello, e sugli effetti biologici indotti dal metallo, misurati a livello molecolare e cellulare, valutando possibili differenze tra organismi provenienti da ecosistemi differenti, in specie differenti provenienti dallo stesso ecosistema, in differenti stagioni e tessuti, e su diversi meccanismi cellulari. A tal scopo, tre specie di bivalvi sono state scelte come specie indicatrici modello, il pettinide antartico Adamussium colbecki, il mitilo mediterraneo Mytilus galloprovincialis, e il pettine glabro Flexopecten glaber. Un ampio set di risposte biologiche è stato analizzato sulla ghiandola digestiva e sulle branchie degli organismi, tra cui metallotioneine, singole difese antiossidanti, capacità antiossidante totale e accumulo di prodotti della perossidazione lipidica, mentre negli emociti degli organismi sono stati analizzati parametri immunitari e di danno genotossico.
I risultati ottenuti mostrano effetti specie-specifici, con differenze tra organismi provenienti da ecosistemi con diversa pressione naturale e antropica; la stagionalità rappresenta un’ulteriore variabile a carico della risposta degli organismi, largamente influenzata da caratteristiche metaboliche e fisiologiche dei vari tessuti. In conclusione, questo lavoro ha contribuito alla crescente conoscenza sugli effetti degli stress multipli sullo stato di salute degli organismi marini.Growing anthropogenic emissions of carbon dioxide are driving ocean warming and acidification, which represent a threat for marine ecosystems integrity. These changes may particularly affect marine organisms that are already coping with other stressors in the marine environment, as high levels of anthropogenic pollution in coastal areas. Changes of temperature and pH could influence inorganic pollutants speciation, bioavailability, bioaccumulation and biological effects in marine organisms. Despite the growing concern and the increased scientific literature available, possible effects of interactions of these multiple stressors are still poorly understood. The main objective of this research activity was to investigate the effects of concomitant higher temperature and reduced pH on the bioaccumulation of cadmium, as a typical inorganic pollutant, and on metal-induced biological effects, measured at low molecular and cellular level. Our aim was to elucidate possible differences in organisms from different ecosystems, in different species from the same ecosystem, in different seasons and tissues, and on different cellular mechanisms. In this respect, three bivalve species were chosen as model indicators species, namely the Antarctic scallop Adamussium colbecki, the Mediterranean mussel Mytilus galloprovincialis, and the smooth scallop Flexopecten glaber. A wide range of biological responses were analyzed in digestive gland and gills, including metal-binding proteins, single antioxidant defenses, total oxyradical scavenging capacity and accumulation of peroxidation products; immune system parameters and onset of genotoxic damages were also measured in haemocytes. Obtained results showed species-specific effects, with differences in organisms from ecosystems with different natural or anthropogenic pressure; seasonality represented an additional variable on organisms’ responsiveness largely influenced by metabolic and physiological features of various tissues. Overall, this work contributed to the growing knowledge on the effects of multiple stressors on the health status of marine organisms.
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McCarthy, Darcy. "Climate change advocates and deniers? Triangulating methods to investigate the language of left- and right-leaning Twitter users." Thesis, Linguistics, 2023. https://hdl.handle.net/2123/29906.
Повний текст джерелаАнотація:
This thesis examines left- and right- leaning users on Australian Twitter in an effort to understand the language use of the different parties to online climate change discourse. The data are taken from Australian Twitter users between 2020 and 2022, and split up via a political affiliation metric in order to create two distinct politically-opposed user groups. Three main techniques are used to identify linguistic differences between the two groups: sentiment analysis, multiple correspondence analysis, and keyword analysis. The findings of this thesis are threefold. Firstly, text data collected on left- and right-leaning metrics are found to be an apt proxy for examining the language of climate change activism and denial. Secondly, climate change activists and deniers on Australian social media speak similarly in terms of grammatical style, but significantly differently in terms of lexical content. Thirdly and finally, triangulating between the three aforementioned methods provides a much clearer picture of language use. In this way, this thesis offers methodological innovations in examining online discourses, as well as important findings on the language use of the various parties to climate discourses on Australian Twitter.
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Beaumier, Maude. "Vulnerability of Inuit women's food system to climate change in the context of multiple socio-economic stresses - a case study of Arviat, Nunavut." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107673.
Повний текст джерелаАнотація:
Nunavut has the highest incidence of food insecurity in Canada, where 56% of Inuit households are believed to experience difficulties in obtaining sufficient food. Food insecurity occurs when food systems are stressed such that adequate nutrition is not accessible, available, and/or of insufficient quality. Inuit food systems comprising traditional and store food components are affected by economic, social and cultural transformations, and ecological changes, most notably associated with climate change. Inuit women have been identified to be particularly vulnerable to food insecurity, a condition that can be exacerbated by climate change stresses on their food system. This research identifies and characterizes the key factors determining Inuit women's food system vulnerability and adaptability to climate change and human stressors, and the factors contributing to food insecurity. This research was conducted in collaboration with the community of Arviat, Nunavut, using a community-based participatory research approach. Arviat is experiencing a high level of food insecurity, particularly among women. Photovoice, semi-structured interviews with Inuit women (n=42) and key informants (n=8), focus groups with women (n=7), elders (n=3) and hunters (n=2), and participant observations were used to collect in-depth qualitative data. Findings show that Inuit's food system in Arviat is sensitive to climate-related risks and changes, but climate change was not identified as affecting women's food security. Human factors such as financial resources and budgeting skills, store food knowledge, decrease in the transmission of country food knowledge, decrease in traditional training, substance use and gambling and high cost of living, negatively impact Inuit women's food security. On the other hand, a strong sharing network, governmental financial support and local educational initiatives help strengthen the food system and improve food security.Le Nunavut connait la plus haute incidence d'insécurité alimentaire au Canada, où 56% des foyers ont de la difficulté à obtenir une quantité suffisante de nourriture. Ce pourcentage dépasse largement la moyenne canadienne. L'insécurité alimentaire se manifeste lorsque le système alimentaire est stressé, provoquant ainsi un accès et une disponibilité inadéquate à de la nourriture de qualité. Le système alimentaire des Inuit, qui se compose de nourriture traditionnelle et d'aliments importés, est affecté par des changements d'ordre économique, social, culturel, et environnemental notamment associé aux changements climatiques. Les femmes Inuit ont été identifiées comme étant particulièrement vulnérables à l'insécurité alimentaire, et donc plus sensibles aux changements climatiques. L'insécurité alimentaire, particulièrement lorsqu'elle est chronique, a des répercussions au niveau de la santé physique, mentale et sociale des femmes Inuit, et ainsi accroît leur susceptibilité aux infections et aux maladies chroniques. Cette recherche améliore la compréhension de la vulnérabilité et la capacité d'adaptation du système alimentaire des femmes Inuit au changement climatique, et ce dans le contexte de stresses socio-économiques. Ce travail identifie et caractérise les facteurs clés qui déterminent la sécurité ou l'insécurité alimentaire chez les femmes Inuit à l'aide d'une méthodologie basée sur l'étude de cas, qui s'inspire d'une approche de recherche participative communautaire (CBRP), et ce en collaboration avec la communauté d'Arviat, Nunavut. Le niveau d'insécurité alimentaire est élevé à Arviat, particulièrement chez les femmes. Diverses méthodes ont été utilisée afin d'obtenir des données qualitatives approfondies, telles que photovoice, entrevues semi-structurées avec des femmes Inuit (n=42) et des informateurs clefs (n=8), groupes de discussions avec des femmes (n=7), des personnes âgées (n=3) et des chasseurs (n=2), ainsi que l'observation participative. Les résultats démontrent que le système alimentaire des femmes Inuit est sensible aux risques et aux changements reliés au climat. Par contre, le changement climatique n'a pas été identifié comme un facteur affectant la sécurité alimentaire des femmes actuellement. Les facteurs humains tels que les ressources financières, la capacité à faire un budget, les connaissances au sujet de la nourriture d'épicerie, la diminution de la transmission des savoirs reliés à la nourriture traditionnelle, la réduction de l'éducation traditionnelle, la consommation de tabac et de drogues, les jeux de hasard et le coût de la vie élevé impactent négativement le système alimentaire des femmes Inuit. Malgré tout, un important réseau de partage et le support gouvernemental et local contribuent à renforcir le système alimentaire et la sécurité alimentaire. Les programmes communautaires à vocation éducative sont important afin d'assurer la sécurité alimentaire à long terme.
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Higdon, Julia Dianne. "Measuring and Modeling Intercultural Attitudes Among Adolescents Across Europe: A Multi-Level, Multiple-Group Analysis Examining Student Attitudes, Intergroup Contact, and School Climate." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:16461055.
Повний текст джерелаАнотація:
European nations, built on democratic foundations, rely on participation that is inclusive of all groups. Among efforts to support social cohesion in Europe, investigating the development of intercultural attitudes—attitudes toward others on the basis of their intersecting group memberships—is a crucial area of research. Further, examining attitudes among adolescents is useful because of their growing capacity to understand complex systems, while still being engaged in formal education in which interventions aimed at developing positive attitudes are often applied. In this dissertation, I used data from the 2009 IEA ICCS (International Civic and Citizenship Education Study) to examine determinants of intercultural attitudes among adolescents (n=16,847) in seven countries across Europe—the United Kingdom (England only), Sweden, Switzerland, Spain, Bulgaria, Poland, and Greece—focusing on cultural contexts and school climates. First, I established the measurement invariance of a variety of measures of intercultural attitudes to support the validity of cross-cultural comparison, using a novel approach in the Bayesian framework. Using this method, I was able to validly compare intercultural attitudes across contexts in Europe, and these findings are interpreted and discussed. Then, I examined the ways in which intergroup contact, gender, and school climates were associated with intergroup attitudes across these seven countries. I found limited evidence of an association between native-born and immigrant contact and positive intercultural attitudes. However, I found that positive intercultural attitudes were consistently associated with positive and democratic school climates, as well as with gender and attitudes toward gender equality. In this dissertation, I present these findings, as well as provide interpretation, discussion, and future directions with regard to educational interventions.Culture, Communities, and Education
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English, Gregory G. "The Change Process and the Implementation of High School Jostens Renaissance Programs: A Multiple Case Study." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/etd/3528.
Повний текст джерелаАнотація:
Motivated by the growing body of research relating to the impact school climate has on student achievement, attendance, behavior, and mental well-being, many educators have implemented initiatives and programs aimed at school climate improvement. Jostens Renaissance is one such program and was the program of focus for this study. Though Jostens has numerous publications and media sources to facilitate the sharing of ideas, there is very little information available regarding the implementation of Renaissance.
The primary purpose of this study was to identify factors that facilitated change in the process of implementing high school Jostens Renaissance programs in order to identify any common factors that may be transferable to other schools. A multiple case study approach was utilized to explore the strategies which facilitated the implementation of Renaissance at three southeastern high schools. Data were collected via qualitative interviews with teachers and administrators who were present at their respective schools prior to, during, and after the implementation of Jostens Renaissance. The three study schools selected for the study were identified by Jostens as having strong Renaissance programs.
Seven main themes related to change factors were identified: need for change, supportive administration, dedicated faculty coordinator, student leadership and participation, faculty buy-in and participation, intentionality in building teacher climate, and perceived quality of the program. Surprisingly, none of the schools experienced any major barriers the implementation. Participants credited the lack of implementation barriers to a perceived need for change among the school community.
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Mortyn, Peter Graham. "Planktonic foraminifera and upper water column variability in the South Atlantic : a multiple species approach to the deep sea sedimentary record of climate change /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035424.
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Kornder, Niklas Alexander. "Using Regression-Based Effect Size Meta-Analysis to Investigate Coral Responses to Climate Change." NSUWorks, 2016. http://nsuworks.nova.edu/occ_stuetd/415.
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Attempts to quantify the effects of ocean acidification and warming (OAW) on scleractinian corals provide a growing body of response measurements. However, placing empirical results into an ecological context is challenging, owing to variations that reflect both natural heterogeneity and scientific bias. This study addresses the heterogeneity of climate change induced changes in coral recruitment and calcification. To discern scientific bias and identify drivers of the remaining heterogeneity, 100 publications were analyzed using a combination of weighted mixed effects meta-regression and factorial effect size meta‑analysis. A linear model was applied to quantify the variation caused by differing stress levels across studies. The least squares predictions were then used to standardize individual study outcomes and effect size meta-analysis was performed on original and standardized outcomes separately. On average, increased temperature significantly reduces larval survival, while ocean acidification impedes settlement and calcification. Coral resistance to OAW is likely governed by biological traits (genera and life cycle stage), environmental factors (abiotic variability) and experimental design (feeding regime, stressor magnitude, and exposure duration). Linear models suggest that calcification rates are driven by carbonate and bicarbonate concentrations, which act additively with warming. Standardizing outcomes to linear model predictions proved useful in discerning strong sources of scientific bias. The approach used in this study can improve modelling projections and inform policy and management on changes in coral community structure associated with the expected future intensification of OAW.
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Altahlawi, Naif Tarik. "Integrated Thermal and Daylight Performance Comparison of Single and Double Glass Skin Facade for Hot Climate Conditions." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/90783.
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Visual integration of the building interior and exterior is one of the charms of today's architecture. The Double-Skin facade system is a technology that can reduce the drawbacks of using glass in a building's elevation. In fact, the double-skin façade (DSF) offers transparency while reducing energy consumption when compared to single-skin systems in cold and moderate weather conditions. However, there is no clear evidence of how the system will perform in hot climate conditions. In this research, a testing procedure was established to experimentally evaluate the performance of the double-skin façade system, data was collected to create multiple regression models, and then evaluate the double-skin façade's performance and compare it to a single-skin system in hot arid climate conditions.Doctor of Philosophy
Improving the quality of indoor environments is a main goal in today’s architecture. Towards this goal, the use of glass and curtain walls is common in office buildings. The building façade is a key factor for the amount of energy consumed to reach comfort levels in the building. That is, because facades influence lighting, glare, heat gain, noise safety and energy usage. Therefore, the use of glass improves transparency which can interfere with comfort levels inside the building due to solar heat gain. The Double Skin façade system is widely adopted in Europe and has been shown to reduce energy used for heating in cold weather. In winter, heat losses can be reduced as the system’s intermediate cavity acts as a thermal buffer. However, there is no clear understanding of how the system will perform in hot arid climate conditions where cooling is the dominant operating mode. A Double Skin Façade can provide shading during the overheating period, while having the desired glass elevations sought by designers. This is due to ventilation and solar control devices located inside the system’s cavity. Being placed between the interior and the exterior glass panels, solar control devices are protected from the weather, which in return decreases its size. Furthermore, the additional glass panel allows windows in the system’s inner layer to be opened for natural ventilation. Unfortunately, the performance of the Double Skin Façade system for hot arid climate is not well documented. Therefore, the primary goal of this research is to compare the thermal and light performance of the Double Skin Façade system to a single façade system for hot weather conditions.
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Chamberlain, Natasha Arlene. "Investigating the influence of climate change, conflict and development interventions on livelihood resilience in pastoralist societies : a multiple case study of the Borana and Samburu." Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/15643.
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East African pastoralist societies are characterised by their inherent adaptability to climatic variability, by way of their sophisticated resource management systems and social institutions which provide the knowledge and flexibility needed to respond effectively to risk and uncertainty. However, the impacts of future climate change, in addition to the myriad of social, political, economic and environmental pressures associated with integrating into an increasingly inter-connected globalised system, may be unprecedented in their scope and range, and are likely to undermine their ability to pursue successful livelihoods while putting at risk the things they value. Responses to these challenges need to be based on an accurate and evidence-based understanding of the complexity and synergistic nature of multiple stressors, in order to avoid narrow quick-fix solutions which may undermine resilience and human security in the longer term. This social science research has used a multi-methods approach to fulfil the following objectives: identify the range of stressors impacting livelihoods and wellbeing within the study areas; investigate the multi-directional associations between climate variability and conflict; and evaluate the influence of development interventions on the characteristics of social resilience. Fieldwork was undertaken in collaboration with two non-governmental organisations, with data derived from ethnographic observations and shadowing, participatory rural appraisal, focus group discussions, semi-structured interviews and household livelihood surveys. Results find that communities within the study areas are faced with multiple and interacting pressures on their lives and livelihoods, and that while climate change impacts are likely to compound vulnerability and undermine human security, they cannot be isolated from the broader context, or from local priorities and lived realities. Violent conflict is identified as being more closely associated with periods of abundant rainfall than those of scarcity or resource competition, with climate-related hazards such as drought being more likely to result in reconciliation and cooperation. Conflict is driven primarily by the broader political economy within the region, along with land boundary disputes and the ethnically-based nature of governance and resource allocation. Pastoralist systems are found to inherently contain many of the characteristics of socio-ecological resilience, with development interventions having the potential to build on these strengths in order to simultaneously promote adaptive capacity and build peace. However, the narrow focus on specific risks by organisations within the study areas, without a broader integration of responses to multiple stressors, may lead to path dependency and maladaptation, and could act to undermine resilience in the longer term. This thesis contributes qualitative empirical evidence to the climate security debate, and demonstrates that peace and cooperation are more likely outcomes than violence in pastoralist regions during periods of climate-related stress. It also provides an analysis of the extent to which development interventions inherently support or constrain adaptive capacity and social resilience to climate change, conflict, and other livelihood pressures.
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Garland, Michael A. "Multi-stress proteomics: The global protein response to multiple environmental stressors in the porcelain crab Petrolisthes cinctipes." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1441.
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Global climate change is increasing the number of hot days along the California coast as well as increasing the incidence of off-shore upwelling events that lower the pH of intertidal seawater; thus, intertidal organisms are experiencing an increase in more than one stress simultaneously. This study seeks to characterize the global protein response of the eurythermal porcelain crab Petrolisthes cinctipes to changes in thermal, pH, and tidal regime treatments, either combined or individually. The first experiment examined temperature stress alone and sought to determine the effect of chronic temperature acclimation on the acute heat shock response. We compared the proteomic response of cheliped muscle tissue following a month-long acclimation to either (1) constant 10°C, (2) daily fluctuation from 10-20°C, or (3) daily fluctuation from 10-30°C, all followed by either a 30°C acute heat shock or 10°C control. We found that ATP supply via the phosphagen system, changes in glycolytic enzymes, muscle fiber restructuring, respiratory protein fragmentation, and immunity were primarily affected by acclimation and subsequent heat shock. Acclimation to the “extreme” regimes (10°C and 10-30°C) resulted in the greatest proteomic changes, while acclimation to the moderate regime (10-20°C) resulted in a more mild response to heat shock (i.e., fewer adjustments to relative protein abundance). The second experiment sought to determine the proteomic response of gill tissue following a 17 d acclimation to daily changes in pH (ambient pH 8.1 vs low pH 7.6), tidal regime (constant immersion vs 6 h emersion), and temperature (ambient 11°C vs 22-31°C heat shock during emersion). Low pH alone reduced expression of molecular chaperones of the endoplasmic reticulum, lectins, and serine proteases involved in activating the prophenoloxidase cascade. It also increased the abundance of Na+/K+-ATPase, nitrogen metabolism enzymes, and induced changes in tubulin expression, all suggesting an increase in ammonium excretion. Addition of emersion during low pH reduced the abundance of several metabolic proteins including those involved in the proposed ammonium excretion mechanism, suggesting a decrease in metabolic function in part to prevent toxic accumulation of ammonium in the branchial chambers. Combined pH, emersion, and thermal stress increased the abundance of proteins involved in cuticle binding and crosslinking. These results indicate that the responses to pH, tidal cycle, and temperature are highly dependent on one another and that changes in ER protein maturation, ion transport, immunity, and cuticle structure are the primary biochemical systems impacted by these environmental stressors in crustacean gill.
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Cramb, Pamela Helen. "The influence of coastal upwelling on the biodiversity of sandy beaches in South Africa." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6553.
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Sandy beaches are often highly allochthonous, depending on external subsidies of carbon and nutrients. Despite this, sandy beach macrofaunal assemblages have received little attention regarding their response to enhanced primary productivity generated from coastal upwelling. This thesis investigates the influence of upwelling on macrofaunal assemblages over a variety of spatial and temporal scales. Spatially, four regions were examined across two biogeographic provinces to remove temperature as a confounding factor, and limit biogeography-specific effects. A nested hierarchical design enabled both large and small scales to be examined and generalities about upwelling effects across multiple areas to be considered. Sampling was conducted in two seasons, and over two years, to test the persistence of any effects. Biogeography and region had the strongest influences on macrofaunal biodiversity. Upwelling influenced macrofaunal assemblages in every region when analyses were conducted at the species level. However, the particular effect, positive or negative, differed among regions depending on local factors, and between the response variables, abundance and biomass. Coarser scales of taxonomy, feeding guild and developmental mode were investigated; however, the influence of upwelling generally became weaker and more varied, and occasionally disappeared. Seasonality was greater on the South Coast but was still important in some analyses on the West Coast. At the small-scale, variation within-beaches was lower than between beaches, assemblage structure remained stable over time, and consistent zonation was not present. The influence of temperature on filtration rate and oxygen consumption of Donax serra was investigated to test a driving mechanism for assemblage responses to upwelling. Feeding ability was significantly reduced at colder temperatures indicating an important factor which may be involved in determining assemblage structure. These results suggest that alterations to upwelling regimes predicted under climate change scenarios will impact sandy beach macrofauna, however the specific outcome will depend on multiple contextual factors.
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Alves, Elis Dener Lima. "Análise das influências geourbanas no clima urbano da cidade de Iporá - Goiás." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-26082016-085246/.
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As modificações impostas pela ação do homem desequilibram o complexo sistema natural, alterando os elementos e características do clima na escala local. A cidade é o exemplo mais significativo destas transformações e o campo térmico urbano é um dos elementos do sistema cidade-atmosfera mais afetados pela mudança do uso e da cobertura do solo. No Brasil, tem-se observado que a grande maioria dos estudos de clima urbano está focada nas grandes cidades, sobre as características do clima urbano para a região Centro-Oeste, especialmente nas cidades de pequeno porte, pouco se conhece. Dessa forma, o objetivo desta pesquisa foi de analisar as influências das características geourbanas na configuração do clima da cidade de Iporá e identificar a variabilidade temporal e espacial das ilhas de calor urbanas. Para tanto, instalou-se oito aparelhos termo-higrômetros para a coleta de dados de temperatura do ar e umidade e duas estação meteorológicas completas, uma na área urbana e a outra na área rural, também foram utilizadas imagens multiespectrais do satélite Landsat 5 e 8. Nas análises dos dados foram utilizadas regressões lineares simples e múltiplas, modelagem, simulações e foi proposto um índice (InGe) para quantificar a influência do homem no clima da cidade. Os resultados evidenciaram que: 1 - em algumas áreas da cidade de Iporá foram observadas tendências significativas de aumento na intensidade das anomalias térmicas; 2 - as variáveis mais influentes na regressão linear múltipla da temperatura de superfície (TS) foram o NDVI que explicou 35% da variabilidade e a densidade demográfica com 25%; 3 - a equação final, proposta como modelo preditor da intensidade máxima da ilha de calor urbana de superfície para a Região do Oeste Goiano obteve r2 de 0,6; 4 - quanto maior a distância da área verde maior a temperatura de superfície, além disso, na primavera ou próximo dela, a intensidade do efeito da área verde na TS foi muito superior ao efeito em outras datas; 5 - os padrões dos desvios da umidade absoluta permitiram afirmar que a área central, mais urbanizada, teve os maiores desvios negativos e áreas com maiores valores de NDVI e próximas aos cursos d\'água apresentaram os maiores desvios positivos de umidade; 6 - as ilhas de calor urbanas em Iporá foram mais frequentes na intensidade de 0,5°C e 1°C, a intensidade máxima observada foi de 3,5°C; 7 - as áreas localizadas nos fundos de vale apresentaram os menores valores térmicos, o que sugere uma drenagem de ar frio. Contudo, constatou-se que a cidade de Iporá, mesmo se tratando de uma cidade pequena, modifica seus parâmetros atmosféricos.The changes imposed by man unbalance the complex natural system, changing the climate elements and features at local scale. The city is the most significant example of these transformations and the urban thermal field is the element of the city-atmosphere most affected by the use and land cover change system. In Brazil, it has been observed that the vast majority of urban climate research is focused on big cities, so that little is known on urban climate characteristics for the Midwest, especially in small towns. Thus, the objective of this research was to analyze the influence of Geourban characteristics in the climate setting of the city of Iporá and to identify the temporal and spatial variability of urban heat islands. Therefore, eight Thermo-Hygrometer devices for collecting air temperature and humidity data and two complete weather stations were settled, one in the urban area and the other in the rural area; Landsat 5 and 8 multi-spectral images of were also used. In data analysis simple and multiple linear regressions, modeling and simulations were used and an index (InGe) was proposed to quantify the man influence on the city climate. The results showed that: 1 - in some areas of Iporá city significant trends of increasing intensity of thermal anomalies were observed; 2 - the most influential variables in the multiple regression of surface temperature (TS) were explained by NDVI (35% of the variability) and population density (25%); 3 - the final equation, proposed as a maximum intensity predictive model of the urban surface heat island for the West Region of Goiás, we obtained an R2 0.6; 4 - the greater the distance from the green area, the higher surface temperature; moreover, in the spring, or close to it, the intensity of the green area effect on TS was by far superior to the effect at other periods; 5 - the patterns of the absolute humidity deviations allow us to affirm that the central area, urbanized, had the highest negative variances, while the areas with higher NDVI values and nearby watercourses showed the highest positive deviations moisture; 6 - urban heat islands on Iporá were more frequent at the intensity of 0.5°C to 1°C, while the maximum intensity was observed at 3.5°C; 7 - the areas located in the valley bottoms had the lowest thermal values, suggesting a cold air drainage. However, it was found that the city of Iporá, despite being a small town, modifies its atmospheric parameters.
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Andersson, Emil, and Mahim Hoque. "The Causal Relationships Between ESG and Financial Asset Classes : A multiple investment horizon wavelet approach of the non-linear directionality." Thesis, Linköpings universitet, Nationalekonomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-159650.
Повний текст джерелаАнотація:
This thesis investigates if Environmental, Social and Governance (ESG) investments can be considered as an independent asset class. As ESG and responsible investing has increased substantially in recent years, responsible investments have entered the portfolios with other asset classes too. Therefore, there is a need in studying ESG investment properties with other financial asset classes. By collecting daily price data from October 2007 to December 2018, we research the directionalities between ESG, ethical, conventional, commodities and currency. Initially, we employed a MODWT, multiscale investment horizon wavelet analysis transformation of the data. The decomposed wavelet data is then applied in pairwise linear and non-linear Granger causality estimations to study the directionality relationships dependent on investment horizon. Additionally, econometric filtering processes have been employed to study the effects of volatility on directionality relationships. The results mainly suggest significant directionality relationships between ESG and the other asset classes. On the medium-term investment horizon, almost all estimations indicate strict bidirectionality. Thus, on the medium-term, ESG can be said to be integrated with the other asset classes. For the long-term horizon, most relationships are still predominantly bidirectional between ESG and all other asset classes. The biggest differences are found on the short-term horizon, with no directionality found between ESG and commodities that cannot be explained by volatility. Furthermore, most directionality relationships also disappear when controlling for the volatility transmission between ESG and currency on the short-term horizon. Thus, our findings suggest significantly more integration between ESG and ethical and conventional as bidirectionality overwhelmingly prevails regardless of investment horizon. As previous research has found similarities between ethical and conventional as well as ESG having similar characteristics to commodities as conventional and ethical, we suggest that ESG should be considered as being integrated and having strong similarities with other equities. Thus, it should be treated as being part of the conventional equity asset class. Deviations from bidirectionality could be caused by ESG variable specific heterogeneity. However, despite our rejection of ESG as an independent asset class, it still carries significant potential as it excludes firms with climate-harming practices, thereby helping in combating climate-related as well as social and governance issues the world is facing.
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Shestakova, Tatiana A. "Tree-ring networks at multiple geographical scales: patterns of coordinated ecological responses to global warming = Xarxes d'anells de creixement en arbres a escales geogràfiques múltiples: patrons de respostes ecològiques coordinades en front a l'escalfament global." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/402622.
Повний текст джерелаАнотація:
Forest biomes are major reserves for terrestrial carbon and thus small shifts in the carbon balance of forests could have a large impact on the global carbon cycle. In spite of unambiguous evidence pointing to climate warming as modern factor increasing the risk of regional forest vulnerability, many uncertainties still remain preventing accurate predictions of forest productivity under future climate change. Improving our understanding of the diversity in tree performance at varying spatiotemporal scales must provide insights on the environmental responses of forests and their function as carbon holders in the coming years. To this end, we proposed a new conceptual framework to investigate tree-ring records by grouping chronologies into potentially homogeneous subsets based on mixed modeling principles, as illustrated for a Quercus spp. dataset from the northeastern Iberian Peninsula. Accordingly, we assessed spatiotemporal patterns of signal strength of tree-ring assemblages across environmental gradients and at multiple geographical scales. We used long-term tree ring-width (TRW) records to assess changes in the temporal coherence of radial growth in multispecies dendrochronological networks. In combination with stable isotope records (carbon isotope discrimination, Δ13C; oxygen isotope composition, δ18O) we characterized the physiological drivers of tree productivity under varying environmental conditions. Finally, we investigated shifts in climate sensitivity of tree growth and performance in response to warming-induced heat and drought effects. We found significant spatial autocorrelations for TRW, Δ13C and δ18O spreading over sites separated up to 1,000 km in Eurasia. However, growth synchrony was not uniform continent-wide, increasing along a latitudinal gradient and, thus, reflecting the extent of environmental coherence in the dominant climatic drivers of regional tree growth (i.e., rainfall patterns at mid latitudes vs. temperature patterns at high latitudes). Also, there were geographically-structured relationships between ring-width and either Δ13C (decreasing northwards and upwards) and δ18O (increasing northwards). These results pointed to limited CO2 diffusion impairing carbon uptake as main mechanism controlling the temporal coherence of forest growth signals at latitudes below 50°N in Europe and altitudes below ~1,600 m a.s.l. in Western Mediterranean. Notably, our results showed an increasing influence of climate on the spatial variability of tree growth over the twentieth century, ultimately leading to enhanced temporal coherence in ring-width records (spatial synchrony) along the local–continental continuum in most European
forests (except Fennoscandia) and also in central Siberia. Growth-climate analyses highlighted coherent shifts in vegetative activity towards more favorable periods depending on site location through an advanced onset of growth in the early season and temperature effects in summer (e.g., strengthening of drought-induced growth limitations in Mediterranean forests and relaxation of cold constraints in boreal forests). Increase in growth synchrony together with a tighter relationship between ring-width and Δ13C over the twentieth century suggested increasing drought effects on growth patterns in southern and central European forests and also in mountain Mediterranean forests. Particularly, our results indicated that warming-induced drought stress is spreading upwards in Mediterranean forests and northwards in temperate forests, overriding taxonomic imprints and local drivers of tree growth. However, uppermost and northernmost forests exhibited a diverging reaction to warming, which highlights the complexities of changing climate effects on peripheral forest populations, hence requiring further examination. Collectively, we demonstrated that broad-scale climatic variation influence ecophysiological traits in both conifers and hardwoods in ways that have previously gone unrecognized, which may help to understand the ecological implications of ecosystem functioning and make better predictions on future forest responses to the ongoing global warming. The evidence for substantial altitudinal and latitudinal variation in tree growth dependencies on leaf-level physiology could be valuable to forecast the extent by which future forests may progressively shift from temperature- to moisture-sensitive growth.Actualmente existen muchas incertezas que impiden predecir con precisión futuros cambios en productividad de los bosques en respuesta al cambio global. Una mejor comprensión del comportamiento de los árboles a diversas escalas espaciotemporales debe proporcionar pistas sobre las respuestas de éstos frente al medio y su función como sumideros de carbono. Esta tesis propone un nuevo marco conceptual para investigar registros de anillos mediante la agrupación de cronologías utilizando modelos mixtos. Se han utilizado series de anchura de anillos (TRW) para determinar cambios en la coherencia temporal del crecimiento en redes multiespecíficas. En combinación con registros isotópicos, se han estudiado los controladores fisiológicos de la productividad. Finalmente, se han investigado los cambios en sensibilidad climática del crecimiento. Se hallaron autocorrelaciones espaciales relevantes para TRW, Δ13C y δ18O entre bosques separados hasta 1000 km en Eurasia. Sin embargo, la sincronía en crecimiento no resultó uniforme geográficamente, incrementando latitudinalmente y reflejando la importancia de ciertos factores climáticos dominantes. Igualmente, se observaron relaciones estructuradas entre el grosor de anillos y Δ13C (disminuyendo altitudinalmente y hacia el norte) o δ18O (incrementando hacia el norte). Ello apunta a una limitación en la difusión intercelular del CO2 como mecanismo de control de la coherencia temporal del crecimiento en latitudes <50°N y altitudes <1,600 m en el oeste mediterráneo. Asimismo, el clima ejerció una influencia creciente sobre la variabilidad espacial del crecimiento en el siglo XX, conduciendo a un aumento en la coherencia temporal de los registros de anchura de anillo (sincronía) en la mayoría de bosques europeos. El análisis de las relaciones crecimiento-clima destacó la presencia de cambios coherentes en la actividad vegetativa hacia periodos de crecimiento favorables. El incremento en crecimiento sincrónico y la relación más estrecha entre anchura de anillo y Δ13C indican que la sequía inducida por calentamiento se extiende altitudinalmente en bosques mediterráneos y septentrionalmente en bosques templados, encubriendo diferencias taxonómicas y factores locales. Colectivamente, se ha evidenciado que la variación climática influencia el comportamiento ecofisiológico en coníferas y angiospermas de forma desconocida hasta la fecha, lo que debería ayudar a realizar predicciones más fiables de la respuesta futura de nuestros bosques.