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京都大学 / 新制・課程博士 / 博士(農学) / 甲第23942号 / 農博第2491号 / 新制||農||1090(附属図書館) / 学位論文||R4||N5377(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 神﨑 護, 教授 北島 薫, 教授 市岡 孝朗 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Not much is known if butterflies can get affected by wind turbines. There are different possibilities how they can affect butterflies. How high the risk is that they can get killed by wind turbines and that butterflies might loose habitats by constructions. But there can also be factors that indirectly makes butterflies thrive better in wind farms. More road edges giving the butterflies resources of nectar from herbal plants growing next to the roads is one of them. This study examines if the distance from wind turbines can affect butterflies density and species diversity within and close to the Windfarm of Örbacken. In total 504 individuals of butterflies of 18 species got recorded within distance of 0-1km from wind turbines for three days. Within the distance of 200-500m from wind turbines 228 individuals of 12 species were recorded and had the highest mid value recorded of both the amount species and individuals. There was significance on the number of species being located within areas 200-500m away from wind turbinesand 0-200m from wind turbines. This suggests that the 200-500m areas from these wind turbines that were within the windfarm, may have a higher species diversity of butterflies. The species diversity of butterflies can possibly be affected by less nectar plants and shelter from the wind in areas close to wind turbines compared to areas 200-500m away from them.

Urbanization is an intensive form of habitat disturbance associated with detrimental effects on biodiversity. However, few studies have investigated its effects on the number, identity and structure of species interactions while considering seasonal fluctuations in communities. Avian seed dispersal is a vital ecosystem service, and the interplay of urbanization and seasonality may impact seed dispersal in ways not predicted by either factor alone. In this study, we evaluate the effects of urbanization and season on avian seed dispersal networks in the southern Appalachians. We found that the number and richness of interactions was unaffected, but the identity of interacting bird species differed based on landscape type. We also found that species strength was impacted by urbanization and season, but other network metrics were unaffected. These results suggest that species identity should be considered when making comparisons of seed dispersal networks, as it may reveal differences between networks with implications for dispersal quality and future plant communities.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24907号 / 農博第2570号 / 新制||農||1102(附属図書館) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 柴田 昌三, 教授 松下 幸司, 教授 德地 直子 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The purpose of this study was to determine the effects of amendments (control, (1x) compost, (2x) compost, (TS) topsoil, and 1x+TS) and microtopography (level, pit and mound) on three parameters (plant species composition, above-ground characteristics of Taxodium distichum, and plant root characteristics) of vegetation growing at a created tidal freshwater swamp in Virginia. None of the soil treatments met the traditional vegetation criteria for federal wetland jurisdictional determination, which only considers dominant species. When the same criteria were used for all of the species, the control, 1x, and 2x treatments met jurisdictional criteria. Considering these findings, vegetative criteria should be re-evaluated for young created wetlands. Compost addition produced the highest proportion of obligate wetland species (30%) while topsoil additions created the lowest proportion of wetland obligates (11%) and the highest proportion of upland plants. The 1x treatment generated the greatest species evenness and lowest weighted average (2.57). Topsoil treatments had the lowest diversity and evenness. Therefore, compost amendment is recommended to increase hydrophytes without compromising evenness and diversity. Bald cypress in pits were taller, had larger trunk diameter and basal trunk swelling than trees growing at higher elevations. Roots growing in mounds were more numerous with greater length than roots at lower elevations. Root length and count were highest for the control soil treatment. Amended treatments may have had lower rooting values because nutrient supply was adequate. Overall, incorporating microtopography and compost during wetland creation had a positive effect on vegetative function in this system. / Master of Science

The effects of seven silvicultural prescriptions were examined one full growing season post-treatment on five sites in the Ridge and Valley, Cumberland Plateau, and Allegheny Plateau of Virginia and West Virginia. Prescriptions were (1) control, (2) understory control with herbicide, (3) group selection, (4) high-leave shelterwood, (5) low-leave shelterwood, (6) leave tree, and (7) clearcut. The effects of each treatment on the vascular plant community were characterized by changes in species diversity, species composition, exotic species richness, Raunkiaer's life-forms, and growth-forms. Pre-treatment, baseline data, and a randomized block design ensured the precision of post-treatment comparisons. High-disturbance treatments (i.e., low-leave shelterwood, leave tree, clearcut) exhibited lower tree-stratum species richness than unharvested treatments. Prescriptions had no effect on shrub-stratum richness. Compared to the control, woody, herb-stratum richness was higher in harvested treatments. Non-woody herb-stratum richness was unaffected. No differences in herb-stratum species diversity were detected using Shannon's (exp H') or Simpson's (1/D) indices. Non-woody species richness per 2-ha treatment plot was significantly higher than the control for high-disturbance treatments. Pre- vs. post-treatment species composition was least similar for high-disturbance treatments, as measured by qualitative and quantitative community similarity indices. Exotic woody species richness was unaffected by treatment; however, non-woody exotic species were more prevalent in high-disturbance treatments. Hemicrytophytes replaced phanerophytes as the most important life-form for harvested treatments. Therophytes were more important in harvested treatments, while the proportion of cryptophtes and chamaephytes did not change in response to treatments. Tree and shrub growth-forms were less dominant in harvested treatments, while graminoids and annual/biennial forbs were more important for high-disturbance treatments. These data represent only the initial results of a long-term study designed to examine plant-community response to silviculture for one harvest rotation length. Long-term results will aid in devising management strategies that address concerns for biodiversity without devaluing traditional resource demands. / Master of Science

Little is known about the tick populations found within the central Appalachian/southwestern region of Virginia. The main focus of this research was to better assess local tick communities in the central Appalachian-Southwestern region of Virginia, which was addressed by determining species diversity, habitat associations, seasonal phenology, pathogen prevalence, and ecological factors that influences tick presence and abundance. A field study was conducted from June 2019 - November 2020 across 8 counties and 3 habitat types. Forested habitats exhibited greater tick species diversity than pasture and urban habitats. Each tick species was observed to be associated with particular habitats. The presence of B. burgdorferi sensu stricto (causative agent of Lyme disease), the human variant of A. phagocytophilum (causative agent of human granulocytic anaplasmosis), and Powassan virus (the causative agent of Powassan encephalitis) were detected in collected field specimens, suggesting a significant threat to public health. The detection of Powassan virus RNA in local Ixodes scapularis ticks is the first evidence of this viral pathogen within the region. The overwintering abilities of ticks, whose populations are expanding or becoming more invasive, including Haemaphysalis longicornis, Amblyomma americanum, and Amblyomma maculatum, were examined through a combination of laboratory and field experiments. Amblyomma americanum and H. longicornis nymphal ticks had a lower supercooling temperature than adult ticks, suggesting their potential to overwinter better; A. maculatum nymphs had similar average supercooling temperatures as the other two species at nymphal stage. Via a field experiment, A. americanum, H. longicornis, and A. maculatum were subjected to natural elements of a Virginian winter in a two-factor design investigating elevation and potential insulation coverage. Elevation and insulation coverage were found to have no significant impact on the overwintering survival of H. longicornis and A. americanum. However, the life-stage of the tick was determined to be a significant factor that dictated the survival of ticks of these species. Overwintering survival of Amblyomma maculatum nymphs was influenced by insulation (proxied by leaf litter); which may be attributed to this tick's preference of drier climate. Low overwintering survival suggests that a tick may not be able to establish a permanent population within the area. / Master of Science in Life Sciences / Ticks can transmit many pathogens, bacteria or viruses that cause disease, to both humans and animals. Diseases associated with ticks can include Lyme disease, Human Anaplasmosis, Ehrlichiosis, Rocky Mountain spotted fever, as well as viral illnesses. The pathogens that cause these diseases are vectored by specific tick species. Currently, there are no published reports of tick species present within the central Appalachian/southwestern region of Virginia. A study to determine local tick populations presence and the factors influencing their maintenance in the environment was conducted. Additionally, field collected specimens were screened to assess pathogen prevalence within the region. I confirm the presence of Borrelia burgdorferi sensu stricto (causative agent for Lyme disease), Anaplasma phagocytophilum (causative agent for Human Granulocytic Anaplasmosis), and Powassan virus within Ixodes scapularis, commonly referred to as black-legged ticks. Habitat (forest, urban, pasture) was a significant influencing factor on the presence of I. scapularis, Amblyomma americanum, and Haemaphysalis longicornis (e.g., the latter species was predominantly found in pasture habitats). Secondly, I investigated how well three sympatric tick species would overwinter within the region. Survival of a tick is heavily dependent upon their ability to withstand desiccation, obtain a blood meal from a host, mate, and reproduce. Certain ticks may be limited to certain regions based on elevation, temperature, and relative humidity. I investigated the influence of elevation and insulation coverage (presence of leaves vs. no leaves) on A. americanum (Lone star tick), H. longicornis (Asian longhorned tick), and A. maculatum (Gulf Coast tick). Elevation and insulation coverage had no significant impact on the overwintering survival of the Lone star and Asian longhorned ticks. Tick survival was mainly dictated by what life-stage they were in; Lone star ticks survived better as adult than at other life stages. Asian longhorned ticks survived better as nymphs than larva and adults. Insulation coverage influenced the overwintering survival of the Gulf Coast tick. These ticks survived better with no leaves, which may be associated with their preference of drier climates.

Classification of relevé data aims to present the best possible explanation of the vegetation within a specific study area. The variety of multivariate techniques available to classify vegetation into ecological communities has developed in recent years, which contributes to uncertainty among vegetation scientists as to which methods and computer software to select for optimum classification results. The wide application of the classical TWINSPAN algorithm along with the Braun-Blanquet approach of plant community descriptions and diagnostic species identification in southern Africa prompted a comparison of classification results between these classical approaches and a modern approach. The modern approach, as being referred to in this study, entails the recent improvement on the classical TWINSPAN algorithm, namely the Modified TWINSPAN algorithm in combination with statistical measures of species fidelity. Comparisons between classification end-results were undertaken at various spatial scales to test whether discrepancies between results obtained from the different approaches are similar when applied to a broad-scale synthesis, an intermediate synthesis and a local-scale classification within a similar vegetation type, the Mopaneveld. Such a comparative study is envisaged to present insight on the credibility of the use of classical approaches in phytosociology at various spatial scales. A modern approach was tested upon three previous vegetation classification studies which followed the classical approach. These vegetation classification studies were all undertaken at different spatial scales and are being referred to as the reference classifications. The data that were subjected to the modern approach were analogous to those used in the reference classifications. The computer package JUICE 7.0 was used in which the Modified TWINSPAN algorithm was applied in combination with statistical measures of species fidelity, which was obtained as a function directly in the JUICE program. Classification hierarchies were constructed for both the classical and modern approach results to compare and describe similarities and discrepancies between the different hierarchical dendrograms. Fidelity syntables were constructed to assist in the grouping of diagnostic species according to highest fidelity values. Such diagnostic species groups were compared with the lists of diagnostic species in the reference classifications. At the broadest spatial scale, comparisons revealed discrepancies between classification results from the classical and the modern approach. The modern approach presented a more robust synthesis of the Mopaneveld in southern Africa since the vegetation units and their associated diagnostic species are ecologically better expressed. The intermediate scale synthesis comparison revealed similar discrepancies, which again question the credibility of the classical approach at broader spatial scales. The application of the modern approach to the local scale classification, however, revealed little difference with the results obtained through the classical approach. Although more alternative classification techniques need to be applied to report on the most robust technique for vegetation classifications across spatial scales, it could be reported that the classical TWINSPAN algorithm is not favorable for vegetation classifications and syntheses beyond the local scale. The ecological reliability of the modern approach at the intermediate scale prompted its application in a synthesis of the riparian vegetation within the Mopane Bioregion of South Africa, which was not achieved in any previous study. Riparian vegetation plays an important role in maintaining good water quality and also provides habitat for many species. Riparian vegetation therefore needs to be classified and described. The synthesis of the riparian vegetation in the Mopane Bioregion of South Africa revealed six distinct plant communities which are described and discussed in terms of diagnostic, constant and dominant species along with variance in plant species diversity. / Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2012