The role of geographic origin and life history stages in invasion ecology: a comparative assessment of Northern European, Ponto-Caspian and North American species

The biological composition of most of the earth’s major ecosystems is being dramatically changed by human activities. The breakdown of natural barriers, as a consequence of an increasingly connected world, has contributed to a rise in biological invasions worldwide with thousands of non-indigenous species established in freshwater, brackish, and marine ecosystems. Identifying traits correlated with invasion success is a central goal in invasion ecology to predict and prevent future invasions. This dissertation is divided into five chapters. Chapter 1 gives a general introduction to the main topic of the thesis, including invasion ecology and possible determinant factors that might influence invasion success such as geographic origin and life history stages. Furthermore, it also explores the influence of experimental design on results in ecology. In Chapter 2, I question the role of geographic origin on invasion success, specifically, whether Ponto-Caspian species are better able to acclimatize to and colonize habitats across a range of salinities than taxa from Northern European and North American regions. The experiments, using eight gammarid species native to those three regions, demonstrated that although species from all three tested regions indicated high tolerance to a wide range of salinities, significant differences in the direction of salinity tolerance were observed among the regions, with Northern European species having a better survival in higher salinities, and Ponto-Caspian species in lower salinities. Therefore, it is important to consider geographic origin as a predictor of invasion success because it might foresee pre-adaptation of certain species due to its evolutionary history. Following these findings, in Chapter 3, I further compare the salinity tolerance of adults and juveniles of three gammarid species originating from Northern European, the Ponto-Caspian and North American regions to determine whether juveniles tolerate salinity changes equally well as adults. During the invasion process, individuals must overcome several challenges and be able to survive and reproduce to establish a successful population. Thus, the role of life history stages in the context of invasion ecology is important to consider. While experimental results determined that both adults and juveniles of all three species endured wide ranges of salinity, juveniles tolerated a narrower salinity range than their parents. The evidence from this study emphasizes the importance of testing several life history stages when constructing models to predict future invasions. In Chapter 4, bearing in mind that the approaches used to test scientific questions may differ not only in spatial scale but also in ecological complexity, I explored how the type of experiment (i.e., scale and ecological complexity) affects the outcome and to what extent the two types of experiments are comparable. Two experiments differing in size and ecological-complexity (i.e. outdoor large-scale community-level mesocosm vs. indoor small-scale two-species laboratory experiment), were conducted to assess the effects of marine heatwaves on two gammarid species. The results revealed that while for one species the population growth was similar independently of the size and ecological-complexity, for the other species, the inclusion of the community seemed to have benefited the species’ growth rate, demonstrating stronger performance in the mesocosm than in the laboratory experiment. These results suggest the importance of biotic interactions and complexity of natural environments in buffering or boosting the effects of environmental stress on organisms while carrying out ecological experiments. Finally, Chapter 5 summarizes the findings from all experiments and concludes that not only geographic origin and life history stages need to be considered in invasion ecology, but also the approach when selecting our experimental designs to answer research questions

Mobility-as-a-service challenges and opportunities in the post-pandemic

In December 2019, the world experienced a pandemic that called into question what we always took for granted, such as our freedom of movement. Tough restrictions imposed across the world were necessary to stem the transmission of the COVID-19 virus and have largely affected the mobility and transport sector. In a first phase, due to the mandatory confinement that forced people not to leave their houses; in a second phase, when the measures eased and people started to have the need to move again, it was necessary to look for alternative means of transport that avoided the gathering of people. In view of the advances that were being made in recent years towards a Mobility-as-a-Service paradigm that advocates multimodal and shared transport, the pandemic has raised many challenges. In this paper, a statistical analysis of the mobility data made available by Apple from January 2020 to March 2021 is presented, where the reduction in the use of public transport becomes evident, leading us to question what the future of Mobility-as-a-Service will be as its foundation advocates, among other aspects, the use of a shared transport model. Despite the challenges that the pandemic has brought to Mobility-asa-Service, a set of opportunities are presented that can be used in the short and medium term to strengthen the paradigm and enhance its massive adoption.5311-8814-F0ED | Sara Maria da Cruz Maia de Oliveira PaivaN/

Are juveniles as tolerant to salinity stress as adults? A case study of Northern European, Ponto‐Caspian and North American species

Aim: Global biodiversity and ecosystems are highly impacted by anthropogenic activities, such as climate change and introduction of non-indigenous species. As numerous species from the Ponto-Caspian region have established in the North and Baltic Seas, as well as in the Laurentian Great Lakes, there have been large number of studies examining environmental tolerance of these species to determine their future potential to spread. However, many of those studies were conducted only on adult stages, while neglecting the possibility that early life history stages might not be equally resilient. Location: Northern European, Ponto-Caspian and North American regions. Methods: To determine whether juveniles would demonstrate the same environmental tolerance as their parents, we examined the salinity tolerance of adults and juveniles of one Northern European (Gammarus salinus), one Ponto-Caspian (Pontogammarus maeoticus) and one North American species (Gammarus tigrinus). Additionally, we compared our study to that of Paiva et al. (Global Change Biology, 24, 2018, 2708), who tested the salinity tolerance of the same species using only adults. Results: Our study determined that both adults and juveniles of all three species tolerated wide ranges of salinity, with juveniles of G. salinus tolerating only slightly narrower salinity range than their parents, while those of P. maeoticus and G. tigrinus much narrower range. Additionally, we determined better survival and higher growth rates of juveniles of G. salinus in higher salinities and better survival of P. maeoticus in lower salinities. Main conclusions: Based on juvenile salinity tolerance, our study further supported findings of Paiva et al. (2018), where Northern European species may be adapted to marine, while Ponto-Caspian to lower saline and freshwater environments. The North American species is probably adapted to intermediate salinities. As juveniles do not tolerate the same salinity stress as adults, we emphasize the importance of testing all life history stages when predicting species resilience to environmental stressors

Development of food bioactives through the valorization of olive oil production wastes

Tesis por compendio de publicaciones[ES]En el presente trabajo se evaluó la viabilidad del uso de radiación gamma para mejorar la extractabilidad de compuestos de interés presentes en muestras de orujo de oliva. Además, se optimizaron las condiciones de extracción para recuperar los principales bioactivos del orujo de oliva irradiado y seleccionar el extracto más prometedor para incorporar como conservante en manzanas recién cortadas con el objeto de extender su vida útil. Se partió de dos tipos de orujo de oliva, Orujo de Aceituna Crudo (COP, crude olive pomace) y Orujo de Oliva Extraído (EOP, extracted olive pomace), que se sometieron a diferentes dosis de radiación absorbidas (5, 10, 16 y 22 kGy) con el fin de encontrar las mejores condiciones de extractabilidad de los componentes bioactivos. [EN]In the present work, the feasibility of using gamma radiation for improving the extractability of valuable compounds present in olive pomace samples was evaluated. Furthermore, the extraction conditions to recover the main compounds from the irradiated olive pomace were also optimized in order to find out the most promising extract to incorporate as a food preservative in fresh-cut apples and to extend their shelf life. Two types of olive pomace, Crude Olive Pomace (COP) and Extracted Olive Pomace (EOP), and different absorbed doses (5, 10, 16 and 22 kGy) were initially assayed to determine the best conditions to improve the extractability of the natural bioactives

Caracterização das necessidades de ventilação do parque habitacional português

Dissertação de mestrado integrado em Engenharia CivilOs elevados consumos energéticos dos edifícios e as emissões de gases de efeito de estufa a eles associados conduziram à degradação do meio ambiente e estão na origem da preocupação ecológica que constitui a marca dos dias de hoje e que se tem vindo a apresentar como uma arma importante na construção de um novo mundo. A preservação da natureza transformou-se numa ética e num estilo de vida que está a mudar o modo como o homem se relaciona entre si e também o modo como o homem se relaciona com o mundo físico. É neste contexto que surge a necessidade e a vontade de trabalhar no sentido de proporcionar o aumento da eficiência energética do setor dos edifícios, que vá ao encontro da preocupação ecológica de defesa do meio ambiente e que ao mesmo tempo garanta a saúde e o bem-estar daqueles que nele vivem. O trabalho a realizar filia-se nesta ideia e procura saber se a ventilação natural pode constituir-se como um mecanismo suficiente para garantir a qualidade do ar interior dos edifícios. De modo a concretizar o objetivo estabelecido determinaram-se os caudais de ventilação necessários nos diferentes espaços de edifícios de habitação, de modo a assegurar a qualidade do ar interior, tendo em atenção o bem-estar dos ocupantes. Para esta análise, foi necessário caraterizar o parque habitacional nacional, selecionando, depois, um tipo de edifícios a estudar e determinando uma amostra que permitisse a realização do estudo. Depois de caraterizados os diferentes espaços dos edifícios da amostra, calcularam-se, com recurso a normas e regulamentações nacionais e internacionais, os respetivos caudais de ventilação necessários e os efetivamente existentes nos edifícios, considerando apenas a ventilação natural. A análise permitiu concluir que é possível assegurar uma boa qualidade do ar interior apenas com recurso à ventilação natural, garantindo o conforto, saúde e bem-estar dos ocupantes dos edifícios. Permitiu ainda perceber que os caudais de ventilação existentes nos edifícios em estudo são significativamente superiores aos valores que estão regulamentados.The high energy consumption of buildings and the associated greenhouse gas emissions have led to the degradation of the environment and are at the origin of the ecological concern that constitutes the mark of our days and which has been presented as an important weapon in the construction of a new world. The preservation of nature has become an ethic and a way of life that is changing the way man relates to himself and also the way man relates to the physical world. It is in this context that appears the necessity and the willingness to work in order to increase the energy efficiency of the buildings sector, that meets the ecological concern of protecting the environment while at the same time ensures health and well-being of those who live in it. The work to be done is based on this idea and seeks to know if the natural ventilation can constitute as a sufficient mechanism to ensure the quality of the indoor air of the buildings. In order to achieve the established objective, the necessary airflow rates were determined in the different spaces of residential buildings, in order to ensure the quality of indoor air, taking into account the well-being of the occupants. For this analysis, it was necessary to characterize the national housing stock, selecting then a type of buildings to study and determining a sample that would allow the study. After characterizing the different spaces of the sample buildings, the respective required ventilation flow rates and those actually existing in the buildings, using only natural ventilation, were calculated using national and international standards and regulations. The analysis concluded that it is possible to ensure a good indoor air quality only by means of natural ventilation, ensuring the comfort, health and well-being of the occupants of the buildings. It also allowed to realize that the ventilation flows existing in the study buildings are significantly higher than the values that are regulated

Ship transport of marine invasive species and its stress resistance

In the context of biological invasions, ship transport plays an important role in the transference of species around the world. During this process organisms are exposed to several stressful conditions, which do not prevent them to arrive in areas where they did not occur before. The marine invertebrates Carcinus maenas and Mytilus galloprovincialis natives in Portugal, have already established stable invasive populations in several regions worldwide. This study exposed organisms of both species to stress conditions similar to what occurs in ballast tanks and on ship hulls. Results showed a high survival of pre-stressed Mytilus galloprovincialis individuals when compared to non pre-stressed organisms when exposed to air exposure, hyposalinity and heat events. However when Carcinus maenas was exposed to heat stress, there was no significant difference between groups with a different stress history. These findings suggest that transport on ships is not only a vector of dispersal but also a vector capable to increase the resistance to stress conditions in potential species invaders by selection of resistant individual; Resumo: "Transporte marítimo de espécies marinhas invasoras e sua resistência ao stress" No contexto das invasões biológicas, o transporte marítimo desempenha um papel importante contribuindo para a transferência de espécies em todo o mundo. Durante este processo os organismos são expostos a variadas condições de stress que não os impede de chegar a áreas onde não ocorriam anteriormente. Os invertebrados marinhos Carcinus maenas e Mytilus galloprovincialis nativos em Portugal, já estabeleceram populações invasoras estáveis em várias regiões do mundo. Neste estudo, submeteram-se organismos de Carcinus maenas e Mytilus galloprovincialis a condições de stress semelhante ao que ocorre em tanques de água de lastro e em cascos de navios. Os resultados mostram uma maior sobrevivência dos indivíduos Mytilus galloprovincialis pré – expostos a condições de stress quando comparado com organismos sem uma prévia exposição a esses eventos de stress, quando expostos ao ar, baixa salinidade e altas temperaturas. No entanto, quando Carcinus maenas foi exposto a temperaturas mais altas, não houve diferença significativa entre os grupos com diferentes exposições ao stress aplicado. Estes resultados sugerem que o transporte marítimo não é apenas um vetor de dispersão mas também um vector capaz de aumentar a resistência a condições de stress em potenciais espécies invasoras, nomeadamente através da seleção dos indivíduos mais resistentes