The study was focused on disturbances by wild boar (Sus scrofa) and their impact on vegetation of semi-dry grasslands (Festuco-Brometea) dominated by Brachypodium pinnatum. The research was conducted in military area Hradiště in hilly region of the Doupovské hory. Wild boar rooting activities is main source of disturbances regime in this abandoned, previously agricultural area. The vegetation of artificial small scale soil disturbances was compared to undisturbed control plots and vegetation of natural disturbances by wild boar. Experimental plots were established during the summer 2007. Consequently a vegetation survey of these plots was carried out and soil was mechanically disturbed. Succession on disturbances was annually monitored. The surrounding natural disturbances were also mapped three times a year as a potential source of diaspores and to assess their frequency and effect on the landscape level. The list of species in the 2m, 4m and 16m distance from the experimental plot was also made. Results: Disturbances by wild boar increased species diversity and spatial heterogeneity of semi-dry grasslands. There were some species found on experimental plot, which were present not in the surrounding matrix. Most of them belong to hemicryptophytes and species with long-term persistent diaspores. Presence of...

Trees adjust wood anatomical structure to environmental conditions, predisposing time series of quantitative wood anatomical parameters to be valuable source of palaeoenvironmental information. In this doctoral project we analysed the response of vessel parameters of i) floodplain Quercus robur to groundwater level fluctuation, hydroclimate variability and extreme events (droughts and floods), and of ii) Betula pendula to mechanical damage caused by various disturbances. Although climatic signal as well as pointer years stored in tree-ring width chronologies of Quercus robur largely differ between sites, quantitative vessel parameters contain spatially- homogenous positive signal of previous year summer temperature and current year winter/early spring temperature. The only between-site difference in wood anatomical chronologies is negative effect of moisture on vessel size in floodplain, which does not occur in not-flooded lowland sites. We suggest that while tree productivity benefits from high water availability, the wood anatomical structure of Quercus robur is constrained by high soil water saturation in floodplain zone. In addition, the response of tree-ring widths to moisture availability is not uniform inside single stand, but subgroups of trees with completely opposite response coexist...

Fire is a fundamental environmental factor that directly shapes many terrestrial ecosystems on Earth. The present thesis attempts to provide a comprehensive overview of the fire dynamics in Central Europe over the course of the last 12,000 years. Based on extensive analyses of charcoal particles deposited in terrestrial and lacustrine sedimentary sequences and carbonized plant tissues deposited in soils, I was able to track past fire dynamics across a range of spatial scales - from the forest stand scale to the landscape scale. First, we described relationships between drivers of recent fire occurrence and proposed linkages to the spatial pattern of Late-Holocene biomass burning. We found factors related to relief characteristics, such as increased thermal flux or terrain roughness, to be important determinants of fire occurrence within the present-day landscape. Contrary to all expectations, anthropogenic drivers seem to have a weak influence at present. Because relief-based factors have been stable throughout the Holocene, it seems probable that habitats of certain types are more predisposed to increased burning. We hypothesized that recurrent fire disturbances may contribute to the long-term maintenance of Pinus sylvestris-dominated forests, which withstood the competitive pressure of broadleaf...

En av de större utmaningarna med ombyggnadsprojekt är de fall när det i byggnaden finns kvarboende eller andra brukare under tiden. En ombyggnad innehåller i regel både bygg- och rivningsarbeten som ofta medför störningar för människor som vistas i eller intill fastigheten. Samtliga störningar är påverkningsbara och kan vid god projektering och produktion minskas. Målet med examensarbetet har varit att ge konkreta förslag på hur ett fastighetsbolag kan arbeta för att öka hyresgästens kvalitetsupplevelse under en ombyggnad som sker i eller intill hyresgästens lokal. Detta har gjorts genom att identifiera vanliga störningar, genom att påvisa hur hyresgästen har påverkats av dessa störningar och genom att undersöka hur tidigare uppkomna störningar har hanterats. I samråd med fastighetsbolaget Vasakronan har tre ombyggnadsprojekt valts. På respektive ombyggnadsprojekt har kontorshyresgäster, intern projektledare och extern projektledare intervjuats.  Även observationer i form av platsbesök och litteraturstudier har genomförts. Studien har resulterat i förbättringsförslag till fastighetsbolaget. Ett av de viktigaste resultaten som studien visar är att ett fastighetsbolag genom tydlig information via olika informationskanaler och genom att säkra att de överenskomna tiderna för störande arbeten efterföljs, kan öka hyresgästens kvalitetsupplevelse vid en ombyggnad. / One of the more difficult challenges with refurbishment projects is when the building is to be kept in use by tenants throughout the time of renovation. A refurbishment project usually contains both construction and demolition activities, of which both often leads to disturbances. In order to minimize these disturbances during the time of refurbishment, and doing so without affecting the production negatively, planning is of key importance. Every disturbance is manageable, and can through good execution of planning and production be minimized. The goal of this study has been to provide the property company with concrete proposals on how to increase tenants quality experience during the time of renovation. This has been achieved by identifying the most common disturbances, how these disturbances have been affecting the tenants and finally how these disturbances have been handled in the past. In consultation with the property company Vasakronan three refurbishment projects of office buildings has been selected for analysis. In addition to interviews that have been carried out with tenants and project managers on each of the three projects, site visits and literature studies have also been performed. The study shows that a property company through the efficient use of communication through various information channels, in conjunction with enforcing that the time periods for production activities classified as sources of disturbances is followed, in fact can increase the level of experienced quality of their tenant during a refurbishment project.

Gropkeramiker är en intressant kultur som utmärker sig under mellanneolitisk tid på grund av de mesolitiska jakttendenserna. Denna text undersöker gropkeramikernas förhållningssätt kring motgångar och resiliens, genom att registrera potentiella motgångar inom kulturen. Detta kommer att genomföras genom att sammanställa källor från tidigare forskning kring kulturen samt utgå från den adaptiva modellen där kollaps och resiliens definieras. De sammanställda källorna inkluderar gropkeramikernas kontaktnät, ritualer, diet, osteologiska analyser, DNA - analyser och handel. Uppsatsen har avgränsat det geografiska området där de primära källorna inkluderar lokalerna: Ajvide, Västerbjers och Jettböle. / Pitted ware culture is an interesting culture during the middle neolithic period due to the mesollithic hunting tendencies. This text examines the cultures approach to setbacks and resilience by registering potential setbacks within the culture. This will be done by compiling sources from previous research on pitted ware culutre and by using the adaptive model where collapse and resilience are defined. The compiled sources include the social network, rituals, diet, osteological analyses, DNA - analysis and trade of the pitted ware culture. This essay has defined the geographical area where the primary sources include the sites of: Ajvide, Västerbjers and Jettböle.

Lack of safety is a problem in many public places in society, including libraries, where disturbances of order and crime are common problems. Perhaps, many people experience the library as a quiet and safe place, without quarrels, vandalism, violence, theft, or harassment, yet all these are recurring problems in libraries. This study is carried out to clarify factors that cause the lack of safety in libraries and to develop measures to counteract these factors. The survey is conducted as a case study of Högdalen library, where the purpose of the study is to understand how the environment at the library affects the safety of the place, based on the visitors' and personnel's safety experiences. In order to get answers to the study's main research question – that is, how visitors and personnel experience the safety at Högdalen library – a questionnaire survey was conducted, answered by 43 library visitors, as well as interviews with four people from the library's personnel. The study also includes an examination and a compilation of statistics from troublesome events that occurred at the library between the years 2017 and 2020 to further – together with the questionnaire survey and interviews – get answers to what problems are most common in the library today. The hope is that the questionnaire survey, the interviews, the statistics, and the study's theoretical and literature basis will provide answers to how crime prevention through environmental design can be used as a reference to improve safety at Högdalen library. The study is delimited and does not include any comparison between Högdalen library and other libraries concerning the safety experience. The results show that visitors and personnel have a positive image of the safety experience at Högdalen library. Most of the questionnaire respondents (83,7 %) have not experienced any situation that has developed the feeling of unsafety, while the personnel, instead, believe that incidents that have been experienced as troublesome have increased their awareness and experiences of how such situations can be handled, and further increased their motivation to strive for a safe environment for all library visitors. Although the above results show a positive safety experience at Högdalen library, a minor number of visitors (16,3 %) experience, or have experienced, the feeling of unsafety in the library's premises. These experiences of unsafety are based on cases linked to disturbances of order, harassment, drugs, or property crimes, but also problems with obstacles, ability to orientate and lines of sight. The personnel also highlight that some troublesome situations – associated with, for example, youth groups and addicts – have contributed to increased stress and a feeling of discomfort, which subsequently has affected their well-being in the workplace. However, it is important to remember that all people experience safety differently, and that a complete elimination of unsafety can thus be difficult to achieve. Nevertheless, it is vital to make every attempt to prevent the existing risks as much as possible. / Otrygghet är ett problem på många offentliga platser i samhället, däribland bibliotek, där både ordningsstörningar och brott är förekommande problem. Förmodligen upplever många människor biblioteket som en lugn och trygg plats, utan bråk, skadegörelser, våld, stöld, eller trakasserier, ändock är alla dessa återkommande problem på bibliotek. Den här studien genomförs med förhoppningen att klara ut orsakerna till otryggande faktorer på bibliotek, och i bästa fall ta fram åtgärder för att motverka dessa faktorer. Undersökningen görs i form av en fallstudie av Högdalens bibliotek, där syftet med studien är att få en ökad förståelse för hur miljön på biblioteket påverkar tryggheten på platsen utifrån besökares och personals trygghetsupplevelser. I syfte att få svar på studiens huvudsakliga forskningsfråga – alltså hur besökare och personal upplever tryggheten på Högdalens bibliotek – görs en enkätundersökning besvarad av 43 biblioteksbesökare, samt intervjuer med fyra personer från bibliotekets personal. Studien innefattar därtill en granskning och sammanställning av statistik från besvärande händelser som inträffat på biblioteket mellan åren 2017 och 2020 för att vidare, tillsammans med enkätundersökningen och intervjuerna, få svar på vilka problem som är mest förekommande på biblioteket idag. Förhoppningen är att enkätundersökningen, intervjuerna, statistiken och studiens teori- och litteraturunderlag ska ge svar på hur brottsprevention genom urban design kan användas som referens för att förbättra tryggheten på Högdalens bibliotek. Studien är avgränsad och innefattar inte någon jämförelse mellan Högdalens bibliotek och andra bibliotek i avseende på trygghetsupplevelsen. Studiens resultat visar att besökare och personal har en positiv bild av trygghetsupplevelsen på Högdalens bibliotek. Majoriteten av enkätrespondenterna (83,7 %) har inte upplevt någon situation som frambringat känslan av otrygghet, medan personalen i stället menar att händelser som upplevts besvärande har ökat deras kunskaper och erfarenheter om hur sådana situationer kan hanteras, samt vidare ökat deras motivation att sträva efter en trygg miljö för alla biblioteks- besökare. Trots att ovannämnda resultat visar en positiv trygghetsupplevelse på Högdalens bibliotek finns det ett mindre antal besökare (16,3 %) som upplever, eller har upplevt, känslan av otrygghet i bibliotekets lokaler. Dessa otrygghetsupplevelser grundar sig på fall kopplat till ordningsstörningar, trakasserier, narkotika eller egendomsbrott, men också problem med hinder, orienteringsmöjligheter och siktlinjer. Personalen belyser också att vissa besvärande situationer – förknippat med exempelvis ungdomsgrupper och missbrukare – har bidragit med ökad stress och en känsla av obehag, vilket fortsättningsvis påverkat deras välbefinnande på arbetsplatsen. Det är dock viktigt att komma ihåg att alla människor upplever trygghet på olika sätt, och att en fullständig eliminering av otrygghet således kan vara svårt att uppnå – men det är trots detta betydelsefullt att i största möjliga grad försöka förebygga de risker som finns.

No description available.

The soil seed bank plays a dynamic role in the regeneration of plant communities after natural and anthropogenic disturbance. In this thesis, I addressed how disturbances influence the vegetation and seed bank of Florida rosemary scrub. In Chapter One I evaluated changes in species composition and spatiotemporal pattern of the vegetation and seed bank along a gradient of disturbance. During the summers and winters of 2007-2009 percent ground cover and seed bank species composition were assessed among replicates of three vegetation types subjected to minimal, moderate, and extreme anthropogenic disturbance (native rosemary scrub, degraded scrub, and agriculturally improved pasture, respectively). These vegetation types shared the same soil and topographic characteristics but differed in disturbance history. I found that species composition and spatial pattern varied with disturbance. In pastures the compositional and structural characteristics of rosemary scrub were lost and only native scrub species able to evade herbivory persisted in this community. Native and degraded scrub differed most from each other in species abundances and spatial pattern. Degraded scrub showed highest abundance of subshrubs and a spike moss species, while rosemary scrub was dominated by shrubs. The seed banks of scrub herbs in degraded scrub had a tendency towards a random spatial distribution that lacked association with aboveground cover. Conversely, rosemary scrub seed banks tended to have an aggregated distribution and were associated with occurrence of conspecific species aboveground, litter, and shrub cover. These results indicated a change in the spatial heterogeneity of the seed banks of scrub herbs in degraded scrub. In Chapter Two I evaluated changes in seed bank density with time-since-fire in native rosemary scrub. Due to large pulses of recruitment immediately after fire and population decline iii with time-since-fire, I predicted seed density with time-since-fire would follow a unimodal function with low density in early and late years post-fire, and highest density at intermediate time-since-fire. I compared seed density data among sites with different time-since-fire: two sites each of three, six, ten and 24 years time-since-fire and three long-unburned sites ( > 24 years). Variability in seed bank composition and density increased with time-since-fire and only recently burned stands were distinctly different from the other time-since-fire age classes. Some species and functional groups did exhibit a quadratic or cubic association to time-since-fire (ruderal herbs, subshrubs, Ceratiola ericoides, Lechea cernua, Paronychia chartacea, Phyllanthus tenellus); however, timing of the peak in seed density varied depending on life span and age of reproductive maturity. Scrub herbs were the most abundant functional group in the seed bank and showed highest density in the first ten years post-fire. This pattern corresponds to the pattern of aboveground species abundance and suggests abundances above- and belowground are closely linked. Understanding the dynamics of the seed bank in both naturally and anthropogenically disturbed communities in Florida rosemary scrub is important for the restoration of scrub habitat and management of existing populations of endangered and threatened scrub species endemic to the Lake Wales Ridge in central Florida.

We investigate attractors of the Verhulst model with delay under the influence of random perturbations. In this work, we study dynamic regimes and bifurcations for the deterministic discrete model in zones of stable equilibria, closed invariant curves and discrete cycles. Here, a stability level of attractors is studied by Lyapunov exponents. Transformations of the closed invariant curve that appears as a result of Neimark-Sacker bifurcation, were analyzed via the rotation number and angular density. A parametric analysis of stochastically forced regular attractors of this model is performed using the stochastic sensitivity functions technique. A spatial arrangement of random states in stochastic attractors is described by confidence domains. The phenomenon of noise-induced transitions in a zone of discrete cycles is discussed. / Мы исследуем аттракторы модели Ферхюльста с запаздыванием под влиянием случайных возмущений. В работе мы изучаем динамические режимы и бифуркации для детерминированной дискретной модели в зонах устойчивых равновесий, замкнутых инвариантных кривых и дискретных циклов. Исследована устойчивость регулярных аттракторов. Замкнутая инвариантная кривая, которая появляется в результате бифуркации Неймарка–Сакера, анализируется с помощью числа вращения и секторной плотности. Параметрический анализ стохастически возмущенных регулярных аттракторов этой модели выполняется с помощью техники функции стохастической чувствительности. Пространственное распределение случайных состояний стохастических аттракторов описывается с помощью доверительных областей. Наблюдается явление индуцированных шумом переходов в зоне дискретных циклов.

В работе изучается распределённая нелинейная математическая модель гликолитического осциллятора Хиггинса с диффузией. Исследуется влияние диффузии на процессы, протекающие в модели, способность модели к формированию пространственных структур и её чувствительность к случайному шуму. Изучаются явления мультистабильности, стохастического доминирования, подавления автоколебаний диффузией, индуцированных шумом переходов между аттракторами. Рассмотрен вариант модели с одной и двумя пространственными координатами. / This thesis studies a distributed nonlinear mathematical model of the Higgins glycolytic oscillator with diffusion. The influence of diffusion on the processes occurring in the model, the ability of the model to form spatial structures and its sensitivity to random noise are investigated. The phenomena of multistability, stochastic preference, suppression of self-oscillations by diffusion, noise-induced transitions between attractors are studied. A variant of the model with one and two spatial coordinates is considered.