Applying patterns in embedded systems design for managing quality attributes and their trade-offs

Embedded systems comprise one of the most important types of software-intensive systems, as they are pervasive and used in daily life more than any other type, e.g., in cars or in electrical appliances. When these systems operate under hard constraints, the violation of which can lead to catastrophic events, the system is classified as a critical embedded system (CES). The quality attributes related to these hard constraints are named critical quality attributes (CQAs). For example, the performance of the software for cruise-control or self-driving in a car are critical as they can potentially relate to harming human lives. Despite the growing body of knowledge on engineering CESs, there is still a lack of approaches that can support its design, while managing CQAs and their trade-offs with noncritical ones (e.g., maintainability and reusability). To address this gap, the state-of-research and practice on designing CES and managing quality trade-offs were explored, approaches to improve its design identified, and the merit of these approaches empirically investigated. When designing software, one common approach is to organize its components according to well-known structures, named design patterns. However, these patterns may be avoided in some classes of systems such as CES, as they are sometimes associated with the detriment of CQAs. In short, the findings reported in the thesis suggest that, when applicable, design patterns can promote CQAs while supporting the management of trade-offs. The thesis also reports on a phenomena, namely pattern grime, and factors that can influence the extent of the observed benefits

Prediciendo la descomponibilidad de la hojarasca: evaluación de caracteres funcionales de hoja, de broza y de propiedades espectrales de seis especies herbáceas del Mediterráneo

Algunos trabajos han explorado métodos fáciles y rápidos de evaluar la decomponibilidad de la broza de grandes conjuntos de especies. Aquí evaluamos tres de los más utilizados en seis especies mediterráneas herbáceas de diferentes familias y formas de vida: (1) 'caracteres de hojas verdes': caracteres de hojas vivas relacionadas a las estrategias de vida de las plantas; (2) 'caracteres de la broza': respiración de la broza durante incubaciones in vitro y propiedades iniciales de la broza; (3) 'propiedades espectrales de las hojas y de la broza': características espectrales (NIR) de las hojas verdes y de la broza. Analizamos las relaciones entre estos métodos y su consistencia para evaluar la tasa de descomposición de la broza en el campo. Las propiedades espectrales de hojas verdes fueron las más precisas para predecir la descomponibilidad a campo, seguidas por el contenido de materia seca de las hojas (LDMC) y el contenido inicial de compuestos no lábiles de la broza. La descomponibilidad in vitro se correlacionó marginalmente con la descomponibilidad a campo. La selección entre los predictores puede depender, entonces, de los instrumentos disponibles. LDMC es el método más económico y fácil de medir para grandes conjuntos de especies que, a su vez, fue constante dentro de las especies analizadas. Alternativamente, en el caso de tener el equipamiento y las calibraciones disponibles, los espectros NIR de las hojas verdes y de la broza inicial representan un método rápido para estimar la descomponibilidad y calidad de la broza al mismo tiempo. Nuestros resultados confirman evidencias previas que para las especies de sistemas semiáridos caracteres estructurales como LDMC y el contenido de compuestos no lábiles son propiedades importantes en el control de la descomponibilidad de la broza. La validez de nuestras conclusiones para un rango mayor de especies debería probarse en futuros estudios.Several studies attempted to find quick and easy methods to assess litter decomposability. We tested three frequently used methods on 6 Mediterranean herbaceous species from different plant families and life forms: (1) ‘green leaves traits’: traits of living leaves related to the strategies of living plants; (2) ‘litter traits’: litter respiration during in vitro incubation and initial litter properties; and (3) ‘leaf and litter spectral properties’: the spectral characteristics (NIR) of green leaves and litter. We analyzed the relationship between these methods and their consistency to assess litter decomposability in the field. Green leaves spectral properties were the most accurate to predict Several studies attempted to find quick and easy methods to assess litter decomposability. We tested three frequently used methods on 6 Mediterranean herbaceous species from different plant families and life forms: (1) ‘green leaves traits’: traits of living leaves related to the strategies of living plants; (2) ‘litter traits’: litter respiration during in vitro incubation and initial litter properties; and (3) ‘leaf and litter spectral properties’: the spectral characteristics (NIR) of green leaves and litter. We analyzed the relationship between these methods and their consistency to assess litter decomposability in the field. Green leaves spectral properties were the most accurate to predict field decomposability, followed by leaf dry matter content (LDMC) and initial content of non-labile compounds. In vitro decomposability marginally correlated with field decomposability. The selection among these predictors may then depend on the instruments available. LDMC is the easiest and least expensive, and is also a constant trait within species. Alternatively, if available, NIR spectra of green leaves and initial litter represent the quickest method for estimating decomposability and litter quality at the same time. Our findings confirm previous evidence that for species from semi-arid systems structural traits like LDMC and non-labile compounds content are important properties controlling species litter decomposability. The validity of our conclusions when a wider range of species is included remains to be tested. decomposability, followed by leaf dry matter content (LDMC) and initial content of non-labile compounds. In vitro decomposability marginally correlated with field decomposability. The selection among these predictors may then depend on the instruments available. LDMC is the easiest and least expensive, and is also a constant trait within species. Alternatively, if available, NIR spectra of green leaves and initial litter represent the quickest method for estimating decomposability and litter quality at the same time. Our findings confirm previous evidence that for species from semi-arid systems structural traits like LDMC and non-labile compounds content are important properties controlling species litter decomposability. The validity of our conclusions when a wider range of species is included remains to be tested.Fil: Perez Harguindeguy, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Cortez, Jacques. Centre d´Ecologie Fonctionnelle et Evolutive; FranciaFil: Garnier, Eric. Centre d´Ecologie Fonctionnelle et Evolutive; FranciaFil: Gillon, Dominique. Centre d´Ecologie Fonctionnelle et Evolutive; FranciaFil: Poca, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentin

Predicting leaf litter decomposability : an exploratory assessment of leaf traits, litter traits and spectral properties in six Mediterranean herbaceous species

Algunos trabajos han explorado métodos fáciles y rápidos de evaluar la decomponibilidad de la broza de grandes conjuntos de especies. Aquí evaluamos tres de los más utilizados en seis especies mediterráneas herbáceas de diferentes familias y formas de vida: (1) ‘caracteres de hojas verdes’: caracteres de hojas vivas relacionadas a las estrategias de vida de las plantas; (2) ‘caracteres de la broza’: respiración de la broza durante incubaciones in vitro y propiedades iniciales de la broza; (3) ‘propiedades espectrales de las hojas y de la broza’: características espectrales (NIR) de las hojas verdes y de la broza. Analizamos las relaciones entre estos métodos y su consistencia para evaluar la tasa de descomposición de la broza en el campo. Las propiedades espectrales de hojas verdes fueron las más precisas para predecir la descomponibilidad a campo, seguidas por el contenido de materia seca de las hojas (LDMC) y el contenido inicial de compuestos no lábiles de la broza. La descomponibilidad in vitro se correlacionó marginalmente con la descomponibilidad a campo. La selección entre los predictores puede depender, entonces, de los instrumentos disponibles. LDMC es el método más económico y fácil de medir para grandes conjuntos de especies que, a su vez, fue constante dentro de las especies analizadas. Alternativamente, en el caso de tener el equipamiento y las calibraciones disponibles, los espectros NIR de las hojas verdes y de la broza inicial representan un método rápido para estimar la descomponibilidad y calidad de la broza al mismo tiempo. Nuestros resultados confirman evidencias previas que para las especies de sistemas semiáridos caracteres estructurales como LDMC y el contenido de compuestos no lábiles son propiedades importantes en el control de la descomponibilidad de la broza. La validez de nuestras conclusiones para un rango mayor de especies debería probarse en futuros estudios.Several studies attempted to find quick and easy methods to assess litter decomposability. We tested three frequently used methods on 6 Mediterranean herbaceous species from different plant families and life forms: (1) ‘green leaves traits’: traits of living leaves related to the strategies of living plants; (2) ‘litter traits’: litter respiration during in vitro incubation and initial litter properties; and (3) ‘leaf and litter spectral properties’: the spectral characteristics (NIR) of green leaves and litter. We analyzed the relationship between these methods and their consistency to assess litter decomposability in the field. Green leaves spectral properties were the most accurate to predict field decomposability, followed by leaf dry matter content (LDMC) and initial content of non-labile compounds. In vitro decomposability marginally correlated with field decomposability. The selection among these predictors may then depend on the instruments available. LDMC is the easiest and least expensive, and is also a constant trait within species. Alternatively, if available, NIR spectra of green leaves and initial litter represent the quickest method for estimating decomposability and litter quality at the same time. Our findings confirm previous evidence that for species from semi-arid systems structural traits like LDMC and non-labile compounds content are important properties controlling species litter decomposability. The validity of our conclusions when a wider range of species is included remains to be tested

Peatland Plant-soil Feedbacks Dictate Ecosystem Properties and Processes

Interactions between plants and soil are increasingly recognised as drivers of ecosystems through dictating ecosystem properties and processes. My thesis explores the linkage between aboveground and belowground in Boreal peatlands, where soil (i.e., peat) is partially decomposed plant material, thus presenting opportunity for strong plant-soil relationships to arise. In an observational study, I show feedbacks between chemical plant traits (e.g., leaf N) of the dominant ecosystem engineer (Sphagnum moss or Carex sedge) and peat environment drive slow or fast cycles to regulate aboveground plant growth and belowground peat properties such as pH, moisture and nutrients, in two contrasting peatland types. In a field experiment, I show pure and mixed litters of dominant peatland plants (Sphagnum and Carex) decompose more quickly in their site of origin, consistent with a home-field advantage. Peatland plant-soil feedbacks shape ecosystem properties and decompositional processes, collectively dictating ecosystem function, such as nutrient cycling and carbon storage

Using leaf economics to find appropriate woody species for rain gardens

Urban rainwater management faces great challenges in the future, caused by expected increase in precipitation and frequency of storms associated with climate change. Constructions such as rain gardens may be a mean for adaptation to, as well as mitigation of these effects. However, growing conditions in rain gardens are challenging for most vegetation, and in particular woody vegetation, often leading to failing rain garden constructions. By gaining information on the responses of different woody species during conditions found in rain gardens, the probability for a successful decision of vegetation increases. This study was made in connection to a research project led by Anna Levinsson at SLU, Alnarp, researching different responses of nine woody species to waterlogging and drought. The species were chosen based on the categorising work by Niinemets and Valladares (2006), and sorted further according to a few additional criteria. This thesis aim to investigate the possible importance of leaf economics when choosing trees for rain gardens, focusing on the conditions during waterlogging. A literature study explored the current knowledge of waterlogging in urban environments, the effect of waterlogging on trees, and plant strategies centred around Grimes CSR theory and leaf economics. The literature study showed that the most damaging factor to plants during waterlogging is the anoxic conditions created in the soil. Several adaptations exist which may increase the survival-rate for woody species during these conditions, such as the ability for altering root growth, hypertrophied lenticels and a permeable cambium. These adaptations are all associated with the longitudinal transportation of oxygen. The knowledge gathered in the literature study provided the base for the experimental study. Measurements of midday leaf water potential (ψL) and stomatal conductance (gl) were conducted as well as measurements of leaf morphology focusing on the leaf trait Specific leaf area (SLA). The results of the experimental study indicated that the ability for SLA plasticity might be important for the survival of trees during waterlogging, since the species deemed most flood-tolerant displayed significant, or almost significant, effect when kept in a waterlogged state. Furthermore, it showed that these species had a higher ψL and showed no significant effect on gl, indicating that these species seem to be able to upkeep water levels in the leaves and inhibit stomatal closure during waterlogging. This was somewhat contradictory to what was previously described in the literature. Further investigations within the responses of ψL and gl towards waterlogging and how plasticity within leaf economics might be related to this are encouraged. This would possibly increase our understanding in what to search for when choosing woody species for rain beds

Effects of Experimental Sowing on Agroforestry Ecosystem Primary Production during Recovery from Agricultural Abandonment in a Semi-Arid Region of Central Western Spain

22 páginas, 11 figuras y 5 tablas.-- This chapter appeared in: Forest ecology and conservation (2): 25-46 (2017) and may be found at https://www.intechopen.com/books/forest-ecology-and-conservationWe present a study of plant species diversity manipulation on abandoned arable fields and show that most diversity effects can be explained by a successional shift from annuals to perennial plant species. We tested the hypothesis that plant mixtures consisted of mid-successional plant species that were expected to occur on the site following secondary succession, and an increase in the initial plant species diversity at the beginning of secondary succession improves the amount of biomass produced. The main aim was to compare the aboveground biomass for the whole plant community and for different functional groups, using 7 years of field data at abandoned arable land in a semi-arid region of Central Western Spain. Significant differences were established for the treatment-year interaction, analysing the perennial-annual species ratio (P:A) in the HD and LD of sowing treatments. The differences were established at the start of the experiment, when the sown species were more effective in the HD-sowing treatment. There was a negative relationship among the productivity and mean richness of the natural colonization (NC) and the analysed sowing treatments (HD and LD). The coefficient of determination of this relationship was significant (R2 = 0.307, F(1, 13) = 5.75, P = 0. 032).The experimental work was supported by the Framework IV Environment and Climate Programme of the European Commission, contract number ENV4-CT95-0002.Peer reviewe

Effects of Experimental Sowing on Agroforestry Ecosystem Primary Production during Recovery from Agricultural Abandonment in a Semi-Arid Region of Central Western Spain

We present a study of plant species diversity manipulation on abandoned arable fields and show that most diversity effects can be explained by a successional shift from annuals to perennial plant species. We tested the hypothesis that plant mixtures consisted of mid-successional plant species that were expected to occur on the site following secondary succession, and an increase in the initial plant species diversity at the beginning of secondary succession improves the amount of biomass produced. The main aim was to compare the aboveground biomass for the whole plant community and for different functional groups, using 7 years of field data at abandoned arable land in a semi-arid region of Central Western Spain. Significant differences were established for the treatment-year interaction, analysing the perennial-annual species ratio (P:A) in the HD and LD of sowing treatments. The differences were established at the start of the experiment, when the sown species were more effective in the HD-sowing treatment. There was a negative relationship among the productivity and mean richness of the natural colonization (NC) and the analysed sowing treatments (HD and LD). The coefficient of determination of this relationship was significant (R2 = 0.307, F(1, 13) = 5.75, P = 0. 032)