Härdighet för vedartade växter förknippas oftast med zonkartans zonangivelser. Det är dock inte enbart härdighetsiffran som bestämmer om en växt är härdig eller inte. Klimatet på platsen är en avgörande faktor för hur en växt klarar sig eller inte.  Via en enkät tog jag reda på vad odlare i Norr- och Västerbottens län tycker om zonkartan och hur de använder sig av den när de väljer vedartat växtmaterial. Nästan alla odlare ställer sig positiva till zonkartans zonangivelser. De påpekade dock brister med användandet av den då den inte tar hänsyn till växtens proveniens, lokalt klimat eller växters krav på odlingsplats vilket är viktiga faktorer som påverkar härdigheten hos växten. Odlarna efterlyste mer information om växternas krav på sin odlingsplats och hur man skapar ett mikroklimat för just den växten i samband med zonangivelsen för växten.  En växtlista med växter som anges med en lägre zonangivelse än den zon den odlas i har skapats utifrån odlarnas egna erfarenheter. Med hjälp av litteraturstudien och odlarnas åsikter har jag skapat ett förlag på hur en komplettering av zonkartan skulle kunna se ut för att förbättra både kunskapen om det lokala klimatet och utöka växtvalen för odling i Norrland. / The hardiness of a plant is often strongly associated with the recommendations on the climate zone map. However, it is not only the climate zone recommendation that determines whether a plant is cold hardy enough to survive and thrive at a certain location.  By sending a questionnaire to local growers in northernmost Sweden I wanted to investigate how the climate zone map is used and how well it works in the northern part of Sweden. Most growers were positive to the recommendations in the map. However, they pointed out that the climate zone map does not take into account the genetic heritage, the local microclimate and the requirements of the location on which the plant is supposed to grow, which are all very important. Growers mentioned that more information about how to create a good micro climate for a certain plant in a certain zone would be very useful. From the questionnaire I have put together a list of plants that growers in northern Sweden have grown outside the recommendation from the climate zone map. And by using information from the growers together with information from my literature study I have created a suggestion on an updated climate zone map to see if it is possible to raise knowledge and increase plant selection in northernmost Sweden.

No description available.

Human-caused forest fires have increased in magnitude and frequency, affecting global vegetation and requiring a re-evaluation of fire regimes. Changing fire regimes have led to reduced burned areas in fire- dependent ecosystems and increased areas in fire-independent ecosystems, resulting in changes in land cover and posing a threat to native plant communities. This study focuses on monitoring vegetation recovery after fires in California, USA, using the Enhanced Vegetation Index (EVI) from MODIS time series. The goal is to determine the full recovery time and half recovery time (HRT) after forest fires in year 2017 and analyze the influence of burn severity on three land cover classes in two different climate zones in California.Analyzes show that the "Closed Forest" land cover type exhibits the longest recovery period, followed by the "Open Forest" type and “Herbaceous/Shrub” type in both climate zones but no general connection between recovery time and climate zone was observed. It is found that burn severity degree affects HRT but not the full recovery time in both Mediterranean and Semi-arid climate zones. The study mainly highlights the variations in forest fire recovery patterns between land cover types, as well as differences observed between climate zones.

De par ses caractéristiques, l’environnement urbain influe significativement sur le climat observé dans et à la périphérie des villes. Il est communément admis que le centre des villes présente fréquemment des températures d’air plus élevées que celles mesurées dans les zones rurales environnantes. Ce phénomène appelé îlot de chaleur urbain intéresse les enjeux relatifs à la santé publique, au confort urbain et à la demande énergétique. Ce travail de thèse propose de caractériser le phénomène d’îlot de chaleur à partir de l'association d'un zonage climatique et de mesures mobiles à haute résolution spatiale dans la canopée urbaine. Il repose sur une approche méthodologique en trois temps. Une classification climatique ("Local Climate Zones" (LCZ)) est tout d'abord appliquée à l'agglomération de Nancy. Ce découpage climatique du territoire sert de support à la réalisation de mesures embarquées effectuées en période estivale à l'aide d'un véhicule instrumenté. Celles-ci ont pour but d'observer in situ les spécificités climatiques des LCZ recensées dans l'agglomération. L'association d'une base de données de relevés météorologiques et de la classification LCZ permet de caractériser le comportement climatique du milieu urbain et de comparer le comportement de différentes typologies de quartiers en présence d'un îlot de chaleur urbain. Cette démarche propose également un cadre théorique pour le développement d'un modèle de diagnostic à partir d'indicateurs urbains et climatiques, avec la perspective de construction d'un outil de prise en compte de l'îlot de chaleur dans le processus de planification urbaine / Urban environment impacts significantly the climate observed within and around cities. In this context, city centers frequently present higher air temperatures than those measured in the rural areas nearby. This phenomenon called urban heat island impacts major issues such as public health, urban comfort and energy demand. This Ph.D. thesis proposes to characterize the urban heat island phenomenon based on the combination of a climatic zoning and high spatial density mobile measurements performed within the urban canopy layer. This study is divided into three steps. A climate classification ("Local Climate Zones" (LCZ)) is first applied to the conurbation of Nancy, France. This climatic zoning is used in order to perform mobile measurements thanks to an instrumented vehicle. These measurements target to observe the climatic patterns of the LCZ built in this conurbation. The combination of meteorological database and LCZ classification scheme allows to characterize the urban climate behavior and to compare the thermal behavior of different neighbourhood types. This approach provides a theoretical framework for the development of a diagnosis model based on urban and climatic indicators. It also brings outlooks regarding the building of a decision-support tool that aims to supply information about urban heat island adapted to the urban planners needs

This study evaluates energy performance and economic analysis of variable refrigerant flow (VRF) systems in U.S. climate locations using widelyepted whole building energy modeling software, EnergyPlus. VRF systems are known for their high energy performance and thus can improve energy efficiency in buildings. To evaluate the energy performance of a VRF system, energy simulation modeling and calibration of a VRF heat pump (HP) type system is performed using the EnergyPlus program based on measured data collected from an experimental facility at Oak Ridge National Laboratory (ORNL). In the calibration procedures, the energy simulation model is calibrated, according to the ASHRAE Guideline 14-2014, under cooling and heating seasons. After a proper calibration of the simulation model, the VRF HP system is placed in U.S. climate locations to evaluate the performance variations in different weather conditions. An office prototype building model, developed by the U.S. Department of Energy (DOE), is used with the VRF HP system in this study. This study also considers net-zero energy building (NZEB) design of VRF systems with a distributed photovoltaic (PV) system. The NZEB concept has been considered as one of the remedies to reduce electric energy usages and achieve high energy efficiency in buildings. Both the VRF HP and VRF heat recovery (HR) system types are considered in the NZEB design, and a solar PV system is utilized to enable NZEB balances in U.S. climate locations by assuming that net-metering available within the electrical grid-level. In addition, this study conducts life cycle cost analysis (LCCA) of NZEBs with VRF HP and HR systems. LCCA provides present values at a given study period, discounted payback period, and net-savings between VRF HP and HR systems in U.S. climate locations. Preliminary results indicate that the simulated VRF HP system can reasonably predict the energy performance of the actual VRF HP system and reduce between 15-45% for HVAC site energy uses when compared to a VAV system in U.S. climate locations. The VRF HR system can be used to lower building energy demand and thus achieve NZEB performance effectively in some hot and mild U.S. climate locations.

This thesis investigates the impact of Green Infrastructure (GI) and Local Climate Zones (LCZs) on air temperature at 2 meters above the ground (T2m) in Norrköping and Linköping, Sweden, with a focus on urban planning and climate resilience strategies. Two concepts of LCZ and the newly developed “3-30-300” GI rule are applied. Two concepts are evaluated under summer 2018 strong heatwave conditions and project future scenarios with a 3°C rise in global temperatures during extreme heatwaves. The results show an increase in mean temperature of about 2.9 °C and an extended duration of heatwaves in 17 days from the summer of 2018 to the possible future. Findings indicate that urban areas adhering to 30% tree canopy coverage and within 300 meters or less of a park show a 0.7°C reduction in median T2m during heatwaves. LCZs with more natural environments and less paved surfaces, such as open low-rise, sparsely built, and open midrise, exhibit lower air temperatures, while densely built areas (compact high-rise) show higher temperatures at night, and wide-open paved areas (large low-rise, heavy industry) show higher temperatures during days. The study underscores the necessity of increasing GI coverage and parks in both cities, highlighting the challenges of equitable GI distribution. Recommendations for future research include selecting cooling-effective indigenous tree species and expanding the scope to additional climate variables. This work provides crucial insights for urban areas in Nordic countries and similar climates, contributing to sustainable urban planning and enhanced climate resilience.

No description available.