Sexual dimorphism in life history traits may influence the distribution of the sexes,population sex ratios, the maintenance of sex in populations, and the evolutionarypotential of a species. In bryophytes, sexual dimorphism in traits related to growth andreproduction may be responsible for female-biased population sex ratios and a lack ofsexual reproduction. I examined the roles of natural selection in maintaining sexualdimorphism in the context of impacts on bryophyte population sex ratios, usingMarchantia inflexa as a model system. My studies included an assessment of amongpopulationvariation in habitat use by the sexes, comparison of phenotypes betweensingle-sex and both-sex populations, a field study of natural selection, and a comparisonof the influence of selection on asexual and sexual fitness components.The sexes of M. inflexa were sexually dimorphic in investment in growth, asexualand sexual reproduction. The sexes were spatially separated in populations, but thesexes overlapped in habitat use. Populations differed in growth, asexual reproductionrates, degrees of sexual dimorphism, and strength of among-trait correlations. Plantsfrom single-sex and both-sex populations differed in investment in growth and asexualreproduction, but the two population types showed the same degree of sexualdimorphism. Thus, local environment may be more influential than the presence of theopposite sex in maintaining sexual dimorphism.Selection on sexually dimorphic traits was both sex-specific and environmentallydependent. Between-sex correlations were not significant in the greenhouse but weresignificant in the field thus, evolution and expression of sexual dimorphism in nature maybe constrained by among-trait and between-sex correlations. Additionally, femalesincurred a cost of plasticity that males did not. Because there was a negative trade-offbetween sexual and asexual fitness, overall lifetime selection may result in a differentpicture of how the sexes experience selection. The combination of sex-specific andenvironment-dependent selection, and sex-specific costs to plasticity may not onlymaintain sexually dimorphic traits but also ensure the persistence of both sexes in apopulation.

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This thesis examined the efficacy of residual forest structure for the preservation and recovery of bryophytes five to six years after partial canopy harvest in boreal mixed-wood forests of northwestern Alberta, Canada. Bryophytes were sampled in two forest types that differed in pre-harvest abundance of broadleaf (primarily Populus tremuloides Michx. and P. balsamifera L.) and coniferous (primarily Picea glauca (Moench) Voss) canopy trees. In Chapter 2, epiphytic bryophytes growing on aspen (P. tremuloides) were characterized by species viability and nearest-neighbour relationships. Epiphyte assemblage structure showed increasing impact with declining retention owing to degradation of growing conditions for species on trees. Chapter 3 provided an analysis of species richness and abundance patterns in relation to residual canopy structure. Bryophytes generally benefitted from higher canopy retention; however, epixylic and epiphytic species were more sensitive to partial harvesting than species on other substrates, and liverworts were more sensitive than mosses. Liverworts exhibited higher among-site differences in richness as retention declined, which partly resulted from increasing numbers of local species extinctions. In an analysis of species-environment relations in partially-harvested forests in Chapter 4, forest moisture was reduced with any degree of harvesting in both forest types. Lower canopy retention and forest moisture levels were associated with reduced abundances of species with particular biological traits, such as limited reproduction and dispersal capacities. Their re-establishment after harvesting may be impeded because of biological and environmental limitations. Coniferous-dominated forests supported higher abundances of liverworts and species with greater moisture requirements than did mixed-wood broadleaf-coniferous forests, and are potentially important refuges of bryophyte source populations. Chapter 5 examined the capacity for bryophyte species to germinate from diaspore banks in forest soils. Species germinated readily from mineral soil samples obtained from harvested sites, including several perennials characteristic of intact forests. Diaspore banks may serve as a persistent source for species colonization at post-disturbance sites, but only under appropriate growing conditions and not for species that were most sensitive to harvesting. Overall, both amount and composition of forest structure retained after partial harvesting are important management considerations for ensuring conservation of the wide variety of bryophyte species in mixed-wood landscapes. / Conservation Biology

The mechanisms behind the high level of plant diversity and endemism observed in the Cape Floral Region (CFR) of South Africa have been the focus of many studies. Recently developed methods that employ DNA sequence data are making major contributions in reconstructing evolutionary histories of CFR species. Concurrently, palaeoenvironmental evidence is used increasingly to explain the impact of past climates on species ranges. This paper combines these two approaches by analysing the distribution of genetic diversity of the Afro-montane liverwort Jamesoniella colorata and associating its inferred evolutionary history with major palaeoclimatic trends in South Africa. Liverworts are generally well-suited for phylogeographical studies because they often have low dispersal rates, broad geographical ranges and long evolutionary persistence. In addition, the high among-population diversity observed in J colorata is conducive to the interpretation of significant historical events. The GIS-based bioclimatic envelope shows a strong correlation between potential habitat and the known distribution of J colorata and indicates that sampling in this study was sufficient to make accurate phylogeographical inferences. A combination of phylogeographical data and population genetics evidence suggests that populations of J colorata in the Western Cape Province have experienced range contractions into upper-montane refugia and range expansions into lower altitudes in response to warming and cooling climatic trends, respectively. These range shifts have probably taken place throughout the Quaternary glacial-interglacials cycles, , which are thought to have been influential in shaping modem patterns of diversity. In lV an attempt to assign approximate dates to the two expansion events inferred for J. colorata, an average chloroplast mutation rate was applied to the trnL-F cpDNA mismatch distribution. The results roughly place the expansions within the last glacial period, demonstrating the general accordance of the phylogeographical and palaeoclimatic data. The molecular work in this study also brought into question the taxonomic status of several specimens that showed distinctly divergent DNA sequences. Preliminary morphological inspection of the specimens revealed subtle but clear differences in leaf and stem anatomy that were once associated with J. oenops, a species synonymised with J. colorata in 1971.

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第20458号 / 人博第808号 / 新制||人||194(附属図書館) / 28||人博||808(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 加藤 眞, 教授 市岡 孝朗, 准教授 西川 完途 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM

Årligen producerar svenska skogsplantskolor runt 400 miljoner plantor till skogsbruket.Lungmossan är ett av de stora ogräsen för de skogliga plantskolorna. Lungmossan breder utsig på plantbäddarna och omöjliggör hanteringen av plantorna. Idag finns det inget tillåtetbekämpningsmedel för att bekämpa lungmossa på marknaden. Behandling av bikarbonat i fastform har visat goda resultat men är svåra att genomföra i stor skala. I detta arbete harmöjligheten att bekämpa lungmossa med vattenlöslig bikarbonatbehandling studerats.Ett plantskoleförsök genomfördes i ett av Skogforsks växthus i Sävar. Försöket bestod av tvåförstudier och sedan ett huvudförsök med 9 olika försöksuppställningar. Totalt ingick 49Starpot 50 kassetter med 24–48 granplantor i varje. Resultatet visade att det går att behandlalungmossa med bikarbonat utblandat med vatten kortsiktigt, men att de skadorna som uppstårunder behandling på granplantorna gör metoden irrelevant. I stället bör vidare studier påbikarbonat i fast form undersökas.

Ozonation has been utilized for water treatment for over 100 years. During that time, the range of applications has grown considerably, and includes the remediation of nursery and greenhouse irrigation water. Ozone is dissolved into irrigation water to kill pathogens and degrade chemical contaminants. By convention, growers remove ozone from solutions, prior to distribution to the crop, to avoid phytotoxic effects. The available literature regarding aqueous ozone (O3(aq)) phytotoxicity is limited, making this a sagacious practice, although the removal does preclude any ancillary benefits beyond the point of treatment. The effects of applying O3(aq) under two irrigation systems are examined. Initial studies suggested O3(aq) concentrations as high as 20 mg⋅L-1 could be applied directly to mineral wool substrate in a limited (one time) fashion without a negative response. To be effective as a remediation tool, however, ozone would need to be applied more frequently (e.g. daily). The effects of daily O3(aq) application, via drip irrigation in mineral wool hydroponic tomato culture, was examined. In the first of two studies, daily applications of 3.0 mg⋅L-1 O3(aq) elicited an overall positive growth response. In a follow-up study, 6.0 mg L-1 elicited a negative response. Nursery operators often utilize overhead irrigation. A study was conducted to determine if overhead irrigation utilizing O3(aq) was compatible with select woody perennial nursery species. The amount of ozone lost from solution during application was examined, as well as crop response to the ozone environment generated. It was shown that 60 to 70% of the ozone was unaccounted for at canopy level, while phytotoxic effects were elicited at emitter concentrations above 1.5 mg L-1. Marchantia polymorpha is a significant weed species in greenhouse and nursery production; a species with few control options. Anatomical features of M. polymorpha suggested sensitivity to O3(aq). Studies were performed to examine contact time (CT) and exposure frequencies required for M. polymorpha suppression. A CT of 0.84 mg⋅L-1⋅min at an application frequency of 3-times/week achieved measurable suppression. / Natural Science and Engineering Research Council (NSEARC); Ontario Ministry of Agriculture Food and Rural Affairs (OMAFRA); Ontario Centres of Excellence (OCE); Purification Research Technologies INC (PRTI); Flowers Canada (Ontario).

<p>The objective of this thesis is to evaluate the ecological consequences of buffer strip retention on riparian and terrestrial biodiversity. Earlier studies on forest buffer strips have evaluated their effectiveness in relation to water quality and aquatic biota. However, forests along streams are species rich habitats for many organism groups. Buffer strip management is assumed to be important also for protecting such species. Current approaches to biodiversity-oriented forest management practices need to be scientifically evaluated. In this thesis the effects on bryophytes and land snails have been evaluated.</p><p>A before-and-after experiment along 15 small streams in northern Sweden showed that buffer strips of 10 m on each side of the stream moderated the negative effects exhibited at the clear-cuts. The number of land snail species remained similar as to before logging and the number of vanished bryophyte species was lower in the buffer strips than in the clear-cuts. The ground moisture influenced the survival rate of land snails at the clear-cuts. At mesic sites many species vanished but at wet sites the snail fauna was unaffected by the logging.</p><p>Many bryophyte species, most of them liverworts, decreased or disappeared in the buffer strips. These were mostly growing on substrates elevated from the forest floor, such as logs, stumps and tree-bases. A number of nationally red-listed species, sensitive for changes in microclimate, were among those decreasing most. Thus, for the species in most need of protection the buffer strips were too narrow.</p><p>An experiment with bryophyte transplants followed over a season showed that wet ground moisture moderated the negative edge effects in narrow buffer strips. On the other hand, the growth in mesic and moist sites was almost as low as in comparable clear-cuts.</p><p>Microclimatic edge effects are stronger at south facing than north-facing edges of forest clear-cuts. This was shown in an experiment using bryophyte growth as an indicator of differences in microclimate. However, the depth of edge influence seemed to be similar between north- and south-facing forest edges, >30 m for one species. An explanation for this could be that wind penetrates deeper into edges than solar radiation and has a more variable direction.</p><p>In conclusion, narrow buffer strips consist entirely of edge habitat. For many species the environment in buffer strips is good enough for persistence. For others, most notably bryophyte species on convex substrates, wider buffer strips are needed to ensure long-term survival. </p>

The objective of this thesis is to evaluate the ecological consequences of buffer strip retention on riparian and terrestrial biodiversity. Earlier studies on forest buffer strips have evaluated their effectiveness in relation to water quality and aquatic biota. However, forests along streams are species rich habitats for many organism groups. Buffer strip management is assumed to be important also for protecting such species. Current approaches to biodiversity-oriented forest management practices need to be scientifically evaluated. In this thesis the effects on bryophytes and land snails have been evaluated. A before-and-after experiment along 15 small streams in northern Sweden showed that buffer strips of 10 m on each side of the stream moderated the negative effects exhibited at the clear-cuts. The number of land snail species remained similar as to before logging and the number of vanished bryophyte species was lower in the buffer strips than in the clear-cuts. The ground moisture influenced the survival rate of land snails at the clear-cuts. At mesic sites many species vanished but at wet sites the snail fauna was unaffected by the logging. Many bryophyte species, most of them liverworts, decreased or disappeared in the buffer strips. These were mostly growing on substrates elevated from the forest floor, such as logs, stumps and tree-bases. A number of nationally red-listed species, sensitive for changes in microclimate, were among those decreasing most. Thus, for the species in most need of protection the buffer strips were too narrow. An experiment with bryophyte transplants followed over a season showed that wet ground moisture moderated the negative edge effects in narrow buffer strips. On the other hand, the growth in mesic and moist sites was almost as low as in comparable clear-cuts. Microclimatic edge effects are stronger at south facing than north-facing edges of forest clear-cuts. This was shown in an experiment using bryophyte growth as an indicator of differences in microclimate. However, the depth of edge influence seemed to be similar between north- and south-facing forest edges, &gt;30 m for one species. An explanation for this could be that wind penetrates deeper into edges than solar radiation and has a more variable direction. In conclusion, narrow buffer strips consist entirely of edge habitat. For many species the environment in buffer strips is good enough for persistence. For others, most notably bryophyte species on convex substrates, wider buffer strips are needed to ensure long-term survival.