The aims of this project were to: 1. further develop the evaluation systems of Westman (1986), Chapman and Underwood (2000) and Wilkins et al (2004) proposed for the assessment of restored ecosystems; and 2. use these developments to evaluate whether the revegetation of agricultural land on the Cumberland Plain, west of Sydney, NSW, has led to the re-establishment of a grassy woodland. The evaluation system developed in this Thesis was designed to compare three key ecosystem attributes. First, to assess how restoration was progressing, the species richness, composition and vegetation structure of abandoned pasture (starting point), was compared to that of restored vegetation of differing ages (putative mid points), and remnants (goal or end point). Refinements of the previous assessment models included formulation of predictions about native and exotic species richness and composition under the assumption that restoration was succeeding, and explicit testing of these predictions by planned comparisons and trajectory analysis of species composition. Second, the small-scale effects of planted tree canopies on species composition were assessed to test the hypothesis that native tree canopies facilitate the return of natives. Third, the effects of fire and neighbour removal on seedling emergence and establishment in pasture, restored vegetation and remnants were examined to explore what factors controlled germination and establishment. The results of this study indicate that to date, there has been a partial success of the restoration program at the study sites: while native species have returned unaided to restored sites, the trajectory of native species composition was not in the direction of remnants. There was however, increased species richness of exotic species detected underneath planted tree canopies. Patterns of seedling emergence observed in this study suggest that recruitment plays a role in the maintenance of the species composition found in restored vegetation, with seedling emergence dominated by exotics The evaluation methodology developed within this Thesis is a transparent and accurate way to measure ecological changes in vegetation that have occurred as a result of restoration.The restoration evaluation methodology further developed here will be useful to an industry that involves tree planting, landcare, revegetation and bush regeneration. It will complement guidelines provided by government and other sources that advise on practical aspects of revegetation and will be one of the few which have examined the success of revegetation in ecological terms that are founded on sound scientific basis. / Doctor of Philosophy (PhD)

The secondary productivity of communities is inherently influenced by the availability and quality of food resources. Movement of organic matter (OM) across landscapes can connect adjacent systems by providing subsidies of carbon and nutrients, implying that alterations of environments from their natural state may affect the productivity of neighboring food webs. The intact terrestrial and marine environments of Fiordland provide a setting to study linkages between the land and the sea. The first general objective of this study was to determine if large but nutritionally poor (nitrogen-poor, carbon-rich) inputs of forest litter support marine secondary production, and to identify pathways for incorporation of this material into upper trophic levels. Pools of marine and terrestrial OM had distinct values of [delta]�⁵N, [delta]��C and [delta]�⁴S, providing high power to estimate the relative use of these sources by the food webs of the fjord-head deltas. Deposit feeding invertebrates (e.g. Echinocardium cordatum, Pectinaria australis) directly assimilated plant detritus. Heterotrophic bacteria on the surface of the sediment assimilated forest litter and provided a potential food source for invertebrates. Chemoautotrophic bacteria fix CO₂ that originates from decomposing forest litter, thus providing an indirect pathway for incorporation of forest litter into the food webs. In the deep basins the strength of the flux of uptake by chemoautotrophic bacteria through the benthic food web into the upper trophic levels was demonstrated by hagfish (Eptatretus cirrhatus) obtaining 38-51% of their nutrition from these bacteria. The ability of a community to utilize discrete sources of OM relies on the presence of specific functional feeding guilds. Marine algae provide a highly nutritive (nitrogen-rich) food source for the fjord communities and fluxes of algae into food webs are facilitated by grazing invertebrates and filter feeders. The second general objective of this study was to determine how the effective loss of filter feeders from inner Doubtful Sound would alter the flux of marine-derived OM to the food webs of the delta communities. The low salinity environment imposed by the hydroelectric power station in Doubtful Sound caused a large reduction in the abundance of the infaunal bivalves Austrovenus stutchburyi and Paphies australis from delta habitats. Clams could tolerate periods of freshwater exposure of [less than or equal to]20 days duration, but the constant freshwater conditions in Doubtful Sound decreased survivorship. In 2004/05 the biomass of these species in inner Doubtful Sound (7.28 tonnes) was 29 times smaller than in Bradshaw Sound (214.12 tonnes). The associated loss of biodeposits (~91 tonnes(DW) yr⁻� in Bradshaw Sound vs. 1 tonne(DW) yr⁻� in inner Doubtful Sound) may have also altered the flux of nutritive OM to the infaunal community. The river delta communities in inner Doubtful Sound appear to have a higher reliance on forest litter than those in Bradshaw Sound, which is apparent as low values of [delta]�⁵N and [delta]��C for estuarine fish (Notolabrus celidotus, Hemerocoetes monopterygius), which act as integrators of the benthic community. This study demonstrates important linkages between terrestrial and coastal marine ecosystems and highlights the role of functional diversity in facilitating fluxes of organic material through food webs.

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 20, 2007). Includes bibliographical references.

Seasonal trends in forage production and environmental parameters for five plant community types within a northeastern Oregon riparian zone were described and modeled using correlation and path analysis. Wet meadows produced the greatest amount of herbage biomass, followed by moist bluegrass meadows, gravel bars, forests and dry bluegrass meadows. Trends in soil moisture generally increased and then declined from spring to fall. Depth to the water table declined and then increased. Soil temperatures steadily increased. Variables driving seasonal forage production varied by community type. Soil moisture was most important in dry bluegrass meadows and least important in wet meadows. Depth to the water table was most important in wet meadows and least important in dry bluegrass meadows. The amount of herbage production which had already occurred was also an important variable in describing biomass production. Streamflow levels and the amount of production having occurred were driving variables in the gravel bar communities. Preference for grazing different riparian vegetation community types and forage intake by cattle was monitored over a three-week grazing period occuring at the end of summer. Concurrent to preference and intake, vegetative and nutritional characteristics of the forage available for grazing were monitored and relationships between these variables and both community preference and intake described through correlation and path analyses. Grazing cattle initially favored communities with highly digestibile forage, hence communities dominated by Kentucky bluegrass were most preferred. Late in the grazing period community preference was best associated with community abundance, indicating that cattle were grazing communities in proportion to their abundance in the pasture. Intake levels were greater during the first year of the study than the second (2.15 versus 1.81 percent of body weight). Daily grazing time declined as livestock neared the end of the grazing period. Intake was correlated with in vitro dry matter digestibility and the amount of time spent grazing, but poorly related to the amount of forage available. The indirect effect of the amount of forage available on intake was greater than the direct effect and functioned through increases in grazing time as a result of increased availability of highly digestible forage. / Graduation date: 1992

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 19, 2010). Thesis advisor: Dr. Charles F. Rabeni. Includes bibliographical references.

Thesis (M.S.)--California Polytechnic State University, 2010. / Title from PDF title page; viewed on March 18, 2010. Major professor: Royden Nakamura, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Biological Sciences." "February 2010." Includes bibliographical references (p. 78-90).

Thesis (Ph. D.)--University of California, San Diego, 2000. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, Dept. of Ecology and Evolution, August 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : 41-46).

A model of an artificial ecosystem has been formulated for use as a tool to investigate the dynamics of autonomous biosystems. The model is part of a composite model of an EcoCyborg which consists of an ecosystem and its control system, both of which are contained inside a cylindrical space station. The objectives of this project were to design a model of the ecosystem, and to develop a method for its creation and implementation within the overall framework of the EcoCyborg Project. / The modeling approach that has been adopted for the ecosystem model is individual-based and object-oriented. This enables the inclusion of a description of the abiotic environment, as well as of the organisms that inhabit it. A total of 1000 species representing a range of taxonomic groups may be modeled. Individuals in each species are described by their behaviours and phenotypic traits. / The ecosystem model will be linked with the other components of the EcoCyborg model in a multi-process simulation under OS/2 Warp. The behaviour of the system will be studied to elucidate preliminary guidelines for the design, maintenance and control of complex systems.