Thesis (doctoral)--Universität Bonn, 2004. / Includes bibliographical references (leaves 125-138). Also available via the internet.

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 144-162).

This thesis includes four separate studies. The first two studies assessed edge effects in a 700-year-old forest. After 20 years of exposure, epiphyte assemblages on the clearcut edge were similar to those of the forest interior, but there were some differences in vertical distribution patterns. Several species restricted to the upper canopy of the forest interior occurred farther down in the crowns of trees on the clearcut edge. Many species were associated with thick moss mats. Thalli of two cyanolichen species were reciprocally transplanted among four tree crowns. Lobaria oregana grew less on the clearcut edge than in the forest interior. Populations of Pseudocyphellaria rainierensis had acclimated to the edge environment. The third study evaluated whether these two species require old growth and/or thick, underlying moss mats to achieve normal rates of growth and mortality. Thalli were transplanted into tree crowns in 13 forest stands representing 4 age classes: old growth, mature, young, and recent clearcut. Wooden racks were used instead of trees in clearcuts. Half of the cyanolichen thalli were transplanted onto thick moss mats, half onto bare bark. Both species grew at least as well in the younger forests as they did in old growth, but growth rates were significantly lower in clearcuts. Mortality rates were very low in young, mature, and old-growth forests but high in clearcuts. P. rainierensis grew significantly better on moss than bare bark. The fourth study evaluated the long-term potential of live tree retention for cyanolichen conservation. Lichen litterfall was sampled in a natural, multiple-age stand containing remnant trees and regenerating forest. Two lichen species (L. oregana and Sphaerophorus globosus) were strongly associated with remnant trees. Biomass of both species was highest near remnant trees and was significantly higher within groves of remnant trees than at the edges of these groves or near isolated trees. Cyanolichen populations appear to have persisted on remnant trees since before the last fire. They are slowly recolonizing the regenerating forest. Retention of live trees, including hardwoods, combined with longer rotation periods, has great potential to maintain cyanolichens in managed forests. / Graduation date: 1996

Thesis (Ph. D.)--Duke University, 2007. / Includes bibliographical references. Also available via the Internet: http://dukespace.lib.duke.edu/dspace/bitstream/10161/181/1/D_Schuettpelz_Eric_a_052007.pdf (viewed May 21, 2009).

Thesis (Ph. D.)--Duke University, 2007. / Includes bibliographical references.

Thesis--University of Wisconsin-Madison, 1976. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 191-196).

Field and culture studies have been carried out with the epiphytic red alga, Ceramium codicola J. Agardh, with the objective of determining what factors in its biology cause it to be limited to growth on one host plant, Codium fragile (Suringar) Hariot. A survey of epiphytes of C. fragile and C. setcheIIii confirm the absence of C. codicoIa on C. setcheIIii and shows that C. codicola is the most abundant epiphyte on C. fragiIe. More species of epiphytes were present in wave sheltered areas. C. codicoIa was not present in samples from the Strait of Georgia. In culture, C. codicoIa grew to reproductive maturity apart from C. fragiIe from spores, but the life history was not completed. The presence of living or extracted C. fragiIe or C. setcheIIii did not promote germination, growth or reproduction of C. codicola, and typically inhibited it. C. codicoIa did not grow well at temperatures above 15°C in culture; C. fragiIe, Ceramium pacificum and C. gardner i grew weII at 10-18°C. Rhizoids of C. codicola have bulbous tips, which appears to be genetically determined. Substratum can affect later development of these rhizoids, which may obscure the bulbous nature of the rhizoid tips. C. codicoIa is unable to produce digitate holdfasts on its rhizoid tips, as was observed in other Ceramium spp. , and may only be able to attach by entangling its rhizoids in loosely constructed substrata such as Codium spp. C. setcheIIii is not suitable because it is too compact, and penetration of rhizoids is inhibited. Field studies show that C. codicoIa is reproductive throughout the year, although reduced in the winter. Thallus length was also reduced in the winter. In addition, thalIi were longer in wave sheltered sites, and longer in the upper regions of their intertidal distribution. Male and female gametophytes and tetrasporophytes of C. codicola exhibit a hetermorphism in branching pattern. Gametophytes differ from tetrasporophytes by having more primary branches and larger angles of branching. Females differ from males by having a higher degree of proliferous branching, resulting in a higher number of primary branches and a higher branching ratio. Branching pattern in females may be the result of continued growth of involucral ramuli, and it may optimize reproductive potential. / Science, Faculty of / Botany, Department of / Graduate

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

The objective of the current study was to analyse the effect of landscape structure (habitat size and exposure to farmland) on the occurrence and abundance of Lobaria pulmonaria, a foliose cyanolichen. Since the agrarian revolution during the 19th century the agricultural landscape has become increasingly fragmented resulting in isolated meadows and wood-pastures surrounded by farmland. Lobaria pulmonaria is one of the species being affected by this habitat change, much due to their dispersal limitations, specific habitat demands and susceptibility to air pollution. 36 localities of two different size classes (< 1.5 ha and > 4.5 ha) and two different exposure classes (exposed or unexposed to farmland) were studied. The occurrence, size of lichen thallus and height of lichen patches on tree trunks were significantly positively affected by habitat size and negatively affected by habitat exposure. The implications of these findings for strategies to manage and conserve L. pulmonaria in a fragmented landscape are discussed.

Placophora binderi can be described as an "obligate epiphyte" as it does not respond well to any culture conditions and is found growing only on other algae in the natural environment. This habit may have arisen as a response to the best available substrate in a harsh environment (Harlin 1971; Moss 1982). Any nutrient transfer which may occur between Placophora binderi and its basiphyte, usually various species of Codium, is probably by diffusion as rhizoids do not penetrate the basiphyte cells but simply lie between the Codium utricles providing better anchorage. A triphasic life history exists with isomorphic gametophyte, carposporophyte and tetrasporophyte generations. The male and female gametophytes are dioecious. This study confirms Scagel's (1953) observations for the development of the juvenile, mature and reproductive thallus. The juvenile develops as an erect polysiphonous thallus which produces a prostrate lobe as an adventitious branch from the basal segments. This prostrate lobe develops into the dorsiventrally flattened mature thallus. Reproductive structures are produced on erect branches which are initiated at the mature thallus margins. The gametophyte develops on evanescent trichoblasts produced on erect reproductive branches while the tetra sporophyte develops within these erect branches. The female gametophyte has a four-celled carpogonial branch with an auxiliary cell forming after fertilisation from the supporting cell. At the electron microscope level several vesicle types were seen in the reproductive organs. In the male, spermatial vesicles are produced which probably aid in release of the spermatia (Kugrens 1980). These are also visible under the light microscope. In carposporogenesis and tetrasporogenesis, three vesicle types are produced. Striated vesicles appear for a short while during the early stages and probably function as protein stores. Fibrillar vesicles are large and visible under the light microscope. These probably act as carbohydrate storage organelles (Triemer and Vasconcelos 1979; Kugrens and West 1973c; Tripodi 1971). Cored vesicles appear late in sporogenesis and probably aid in adhesion once the spores have settled (Chamberlain and Evans 1973; Wetherbee 1978). Carpospores follow the "serial release" type pattern observed in Polysiphonia (Boney 1978). Tetraspores are released singly via a rupture in the tetrasporangial wall as in Ceramium rubrum (Chamberlain and Evans 1973). Both carpospores and tetraspores germinate in the typical bi-polar Ceramium-type pattern described by Dixon (1973)