Two of the most pressing questions involving ancient bristlecone pines are how microsite factors lead to differences in tree responses to climate at high-elevation sites, and how global change has impacted growing season events. Disparities in climate response at treeline and subalpine locations have been associated with local environmental characteristics while the increasing growth trend found at treeline has been linked to warming. In this study, environmental conditions were considered in order to identify microsite differences between trees growing at two different elevations on four aspects of a conical-shaped mountain in the White Mountains, California. Dendrochronological, environmental, correlational, and spectral methods were employed to explore differences in ring-width chronologies. Albedo, soil thickness, and percent slope led to ring-width variability. Northwestern upper site was most highly correlated with precipitation, while the Southeastern lower site showed a strong negative correlation with temperature. This work indicates that selection of climate-sensitive trees a priori necessitates the consideration of local environmental factors, and these microsite differences resulted in different climate responses between nearby trees. By monitoring growing season events at the historic phenology site from the 1962-64 (Fritts 1969), natural variations and responses to climate change can be identified. Morphological and physiological phenophases, dendrometer traces, and environmental data were collected throughout the summers of 2007 and 2008. Duration and timing of cambial activity (tracheid lifespan) in the present study were similar to those recorded in the Fritts (1969) investigation, while pollination onset and bud opening occurred earlier in this study. No change was found in duration and timing of cambial activity suggesting that changes in cambial phenology are not an explanation for the increasing growth trend found at upper forest borders. On the other hand, changes in bud opening and pollination onset may be related to recent warming. To monitor diurnal and seasonal stem variability as part of phenologic studies on several trees, a point potentiometer dendrometer was designed. The newly designed point potentiometer dendrometer was tested in multiple environments and found to be versatile, cost-effective, and portable, working well in semi-arid and arid environments.

農林水産研究情報センターで作成したPDFファイルを使用している。

Modeling the seedling recruitment microsite involves characterization of the soil environment of the shallow profile from which weed seedlings recruit. Understanding the environment of the seedling recruitment microsite is the prelude to weed emergence studies. Because of spatial and temporal heterogeneity of the recruitment microsite, sufficient measurements are often not feasible. An experiment was established in 2003 and 2004 across topography within an annually cropped field in south-central Manitoba to determine the effect that hillslope aspect and position, and soil residue and depth would have on microsite environment within the shallow seedling recruitment zone. Microclimatic, topographic, soil surface and soil properties were assessed in the context of the weed recruitment microsite. The soil water retention characteristic was measured by pressure plate to determine water availability to germinating seeds at the various topographic positions. The soil water characteristic was evaluated across topography and soil depth. Evaluation of the soil water characteristic by pedotransfer function indicated that a single soil water characteristic is representative of the recruitment zone. Field and laboratory experimental measurements were used as parameterization for the simultaneous heat and water (SHAW) model to generate continuous water and temperature profiles for the recruitment zone. Soil temperature and temperature fluctuation decreased with depth in the recruitment zone. Despite differences of texture, bulk density, and organic matter across topography and soil depth, the soil water characteristic differed only across topography. Soil water potential fluctuated considerably at the soil surface due to numerous precipitation events and direct evaporation. Implications for germinating seeds is that the seedling recruitment zone is influenced by spatial effects of topography and the vertical location of the seed microsite. Physical process based modeling used in this study to predict temperature and water within the seedling recruitment zone enables better understanding of interactions between above-ground microclimate and the recruitment microsite. Such interactions enable linkage between atmospheric models and recruitment models that can enhance our ability to evaluate crop management decisions.

Modeling the seedling recruitment microsite involves characterization of the soil environment of the shallow profile from which weed seedlings recruit. Understanding the environment of the seedling recruitment microsite is the prelude to weed emergence studies. Because of spatial and temporal heterogeneity of the recruitment microsite, sufficient measurements are often not feasible. An experiment was established in 2003 and 2004 across topography within an annually cropped field in south-central Manitoba to determine the effect that hillslope aspect and position, and soil residue and depth would have on microsite environment within the shallow seedling recruitment zone. Microclimatic, topographic, soil surface and soil properties were assessed in the context of the weed recruitment microsite. The soil water retention characteristic was measured by pressure plate to determine water availability to germinating seeds at the various topographic positions. The soil water characteristic was evaluated across topography and soil depth. Evaluation of the soil water characteristic by pedotransfer function indicated that a single soil water characteristic is representative of the recruitment zone. Field and laboratory experimental measurements were used as parameterization for the simultaneous heat and water (SHAW) model to generate continuous water and temperature profiles for the recruitment zone. Soil temperature and temperature fluctuation decreased with depth in the recruitment zone. Despite differences of texture, bulk density, and organic matter across topography and soil depth, the soil water characteristic differed only across topography. Soil water potential fluctuated considerably at the soil surface due to numerous precipitation events and direct evaporation. Implications for germinating seeds is that the seedling recruitment zone is influenced by spatial effects of topography and the vertical location of the seed microsite. Physical process based modeling used in this study to predict temperature and water within the seedling recruitment zone enables better understanding of interactions between above-ground microclimate and the recruitment microsite. Such interactions enable linkage between atmospheric models and recruitment models that can enhance our ability to evaluate crop management decisions.

This thesis is concerned with designing an internet shop for company. Based on the knowledge and information gained in the theoretical part and in the company's proposed solution shop which will improve the promotion of the company and bring new customers.

There are generally two contrasting alternatives to what limits recruitment in plants, namely the availability of seeds (seed limitation) or the quality or quantity of suitable sites (microsite limitation). Dust seeds, the smallest existing seeds, lack or have minimal nutrient reserves. During germination and initial development they consequently parasitize on mycorrhizal fungi. This is called mycoheterotrophy, and can vary in degree of fungal dependency in adult plants from full, partial or initial mycoheterotrophy. The aim of this thesis was to investigate the recruitment ecology of mycoheterotrophic Ericaceae (tribe Pyroleae) species with dust seeds, and to determine what limits their recruitment. The investigated species were: Chimaphila umbellata, Moneses uniflora, Orthilia secunda, Pyrola chlorantha, P. minor and P. rotundifolia. This aim was achieved by combining field experiments (seed sowing) with isotope analysis and fungal host pyrosequencing. Results provide evidence that the species in Pyroleae are heterogeneous, not only with regard to their degree of mycoheterotrophy, but also concerning germination and early seedling development. A combination of microsite and seed limitation is thus likely to be of importance for all studied species, but the relative importance of these limitations varies among species. Despite having adaptations for wind dispersal the majority of the seeds were deposited in close vicinity of the seed source. But with high seed production at least some seeds should be able to disperse long-distance. Seedlings of all studied species were found to associate with a wide range of ectomycorrhizal fungi, at least during their initial developmental stages. There seems to be a tendency for host narrowing in some Pyroleae species, but not as strict as the host specialization seen in fully mycoheterotrophic Monotropa hypopitys, supporting the hypothesis of geographical and developmental host shifts. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.</p>

Submitted by (edna.saturno@ufrpe.br) on 2016-06-21T12:53:25Z No. of bitstreams: 1 Juliana Ramos de Andrade.pdf: 535601 bytes, checksum: 6196e7d4ba3109b000c13f69d90f6c56 (MD5) / Made available in DSpace on 2016-06-21T12:53:25Z (GMT). No. of bitstreams: 1 Juliana Ramos de Andrade.pdf: 535601 bytes, checksum: 6196e7d4ba3109b000c13f69d90f6c56 (MD5) Previous issue date: 2012-02-14 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The different conditions for the establishment of plants such as water availability, light intensity, shading preserved fragments differ from the conditions of anthropogenic areas. In dry environments, the herbaceous cover predominates in the re-colonization of deforested areas, can act as a good group to evaluate the biological impacts of changes in habitat heterogeneity in the process of resilience of dry forests. Therefore, the objective was to evaluate whether the natural regeneration of the herbaceous layer in two microhabitat (parts exposed to direct sunlight and diffuse light) differed between preserved and disturbed areas of scrub and describe how this occurs. The study took place in the semi-arid(caatinga) in preserved and disturbed areas, where they were established 50 plots of 1 m² in area, with 25 allocated in microhabitat called direct light and 25 in microhabitat called diffuse light, we assessed the density, height , number of living individuals, number of individuals killed and fruit yield of each species. The herbaceous species were selected for study Delila biflora (Asteraceae), Gomphrena vaga (Amaranthaceae) and Pseudabutilon spicatum (Malvaceae), significant differences between areas and between preserved and anthropogenic microhabitat of direct and diffuse light in terms of density and survival only for first two species. Fruit production was higher in the area preserved for the three species. The study concludes that: 1. the effect of the existence of microhabitat with direct light and diffuse light in areas preserved and anthropogenic depends on the species considered, 2. populations sensitive to variation in light intensity vary in the number of individuals, height and fruit production of plants 3. resilience in areas of anthropogenic semi-arid environments can be characterized by the existence of spatial heterogeneity on the emergence and survival of herbaceous seedlings, suggesting that regeneration areas can occur by anthropogenic spots. / As diferentes condições de estabelecimento das plantas como a disponibilidade de água, intensidade luminosa,sombreamento em fragmentos preservados diferem das condições de áreas antrópicas. Em ambientes secos, a cobertura herbácea predomina na re-colonização de áreas desmatadas, podendo funcionar como um bom grupo biológico para avaliar os impactos das mudanças da heterogeneidade de habitats no processo de resiliência de florestas secas. Diante disso, objetivou-se avaliar se a regeneração natural do estrato herbáceo em dois microhabitates (trechos expostos à luz direta e a luz difusa) diferia entre áreas preservadas e antropizadas da caatinga e descrever como isso ocorre. O estudo ocorreu no semi-árido brasileiro (caatinga) em áreas preservada e antropizada, onde foram estabelecidas 50 parcelas de 1 m² por área, sendo 25 alocadas no microhabitat denominado luz direta e 25 no microhabitat denominado luz difusa, foram avaliadas a densidade, altura, número de indivíduos vivos, número de indivíduos mortos e produtividade de frutos de cada espécie. As espécies herbáceas selecionadas para o estudo foram Delilia biflora (Asteraceae), Gomphrena vaga (Amaranthaceae) e Pseudabutilon spicatum (Malvaceae), houve diferença significativa entre áreas preservada e antrópica e entre microhabitates de luz direta e difusa quanto à densidade e sobrevivência apenas para as duas primeiras espécies. A produção de frutos foi maior na área preservada para as três espécies. O estudo conclui que: 1. o efeito da existência de microhabitates com luz direta e luz difusa em áreas preservada e antrópica depende da espécie considerada; 2. as populações sensíveis à variação da intensidade luminosa apresentam diferenças quanto ao número de indivíduos, altura e produção de frutos das plantas; 3. a resiliência de áreas antrópicas de ambientes semi-áridos pode ser caracterizada pela existência de heterogeneidade espacial quanto a emergência e sobrevivência de plântulas herbáceas, sugerindo que a regeneração de áreas antrópicas possa ocorrer por manchas.

Abstract Plant community composition and diversity are determined by the balance between rates of immigration and extinction. Processes of immigration to a local community, i.e. propagule availability and dispersal of propagules between and within habitats, set the upper limit for the pool of species potentially capable of coexisting in a community, while local biotic interactions, i.e., competition, facilitation, herbivory and interactions with below-ground ecosystem components, and environmental factors control colonisation and establishment, and determine the persistence and dynamics of already existing species. In this thesis, I studied (1) the interactions between propagule availability, biotic and environmental constraints on colonisation, and (2) the interdependence between biotic and environmental factors regulating community processes in already established resident vegetation. First, I found that both propagule availability and competition with adult plants limited the rates of colonisation and total community diversity in a relatively low-productive tundra ecosystem. Long-term exclusion of mammalian herbivores and alleviation of nutrient limitation by fertilization increased the intensity of competition with established vegetation, and diminished immigration rates. In addition, I also found that community openness to colonization depended on the initial community properties, i.e., the functional composition and the traits of dominant plants in resident vegetation, which mediate the effects of nutrient addition and biomass removal on immigration rates. Second, adult plants in the resident vegetation experienced an increased extent of neighbourhood competition and herbivory in nutrient enriched conditions and in naturally more fertile habitats. However, the effects were also species-specific. On a community level, release from heavy grazing favoured lichens over graminoids and increased species richness. Furthermore, I also showed that plant community composition was strongly linked with soil organic matter quality and microbial community composition, and that these vegetation-soil-microbe interactions varied along a gradient of soil pH. Overall, my results emphasise that propagule availability, biotic and environmental control over community processes are strongly interconnected in tundra ecosystems. Especially, my findings highlight the role of plant competition and herbivory and their dependence on soil nutrient availability in governing colonisation and resident community dynamics. My results also indicate that plant functional composition and traits of dominant plants are of great importance in channelling community responses to external alterations and dictating plant-soil interactions.

The sagebrush steppe is a particularly sensitive ecosystem that is easily disturbed by fires, oil and gas extraction, woody-plant encroachment, and overgrazing. The natural regeneration of native species following a disturbance within this system is typically slow and sporadic, which allows invasive grasses to occupy the landscape. Attempts to assist the recovery of these landscapes through direct seeding is commonly met with poor success rates, particularly in lower elevation, drier sites. Novel seed enhancement technologies and planting techniques that mitigate limiting factors impairing restoration efforts may improve the likelihood of restoring these degraded areas. For chapter 1, we evaluated a solid-matrix priming technique, where bluebunch wheatgrass (Pseudoroegneria spicata) and Lewis flax (Linum lewisii) were primed and then the priming matrix and seed were pelleted together. We evaluated primed seed that had been incorporated into pellets at two field sites against seed that was pelleted but been left unprimed, and untreated seed (control). These three seed treatments were planted in the spring (mid-march) in shallow (2-cm) and deep (15-cm) furrows, in a complete factorial design. We found that primed seeds generally produced higher plant densities than control seed at the beginning of the growing season; however, its influence diminished towards the end of the growing season. We also found that deep furrows increased plant density throughout the growing season and even into the following year. The combination of priming and deep furrows outperformed control seed in shallow furrows in all measured metrics. For chapter 2, we evaluated a seed conglomeration technique for improving Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis) emergence and survival under fall and winter plantings. The trial was implemented at five sites across Utah and Nevada in a randomized complete block-split-split plot design, with site, and planting season, comprising the split-plot factors. Each site and season combination was seeded with conglomerated and control seed. We found that in most cases, a fall seeding of Wyoming big sagebrush was either the same or more successful compared to planting on the snow in the winter, which is the current suggested practice. Our results also demonstrated that seed conglomeration produced higher plant densities compared to control seed throughout the growing season. The higher density of plants produced from conglomerates combined with the improved seed delivery provided by the conglomeration technique was estimated to offset the cost in producing conglomerates and reduce overall restoration costs by 41%.

This diploma thesis "Development of model of goals, instruments and performance indicators for digital advertising campaigns for universities" deals with the issue of marketing commu-nication and is specifically focused on advertisement of higher education in the Czech repub-lic. Theoretical part examines goals of marketing communication, instruments of digital adverti-sing campaings and their performance indicators. In practical part, this knowledge is further modified to suit the specific segment of higher education and there is created a model of goals, instruments and performance indicators. This model is then used as a base for analysis of the digital campaign Buď dobrej!, which had been made for the University of economics in Prague, specifically for the Faculty of informa-tics and statistics. Using the results from the previous analysis, we made practical recommendations, which further expand the model created in the practical part.