Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 146-166). Also available on the World Wide Web.

Thesis (M.S.) -- University of Montana, 2009. / Title from author supplied metadata. Description based on contents viewed on August 12, 2009. Author supplied keywords: native plant restoration ; nonnative seed ; road decommissioning ; road removal ; seed establishment ; soil bulk density ; water holding capacity ; watershed restoration. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 95-100). Also available on the World Wide Web.

Invasive woody shrubs are a problem when they displace native species and threaten habitats, especially those that harbor rare or endangered species. They not only compete with native plants, but also alter habitat and food that many organisms depend upon. Invasive plants undergo a release from their specialist predators in the nonnative range, providing them advantages over native species. Because modes and pathways of how invasive species spread are not fully understood, predicting spread and implementing restoration ecological controls remain inexact. Due to the lack of comparative studies on woody shrubs, especially invasive privets, we understand very little about conditions affecting their invasiveness. A study was conducted near Dallas, Texas to determine if privet has allelopathic properties that influences growth of native plants. Soil nutrients and other analyses were made and compared between field plots supporting privet, plots in which privet has been removed, and plots where privet has not been observed. In some field plots, natives were planted under the three previously mentioned conditions, and their survival and condition were monitored to evaluate effects of privet on their establishment and growth. It was found that Chinese privet did hinder seed germination in red mulberry, soapberry and beautyberry and root formation in beautyberry cuttings. The soil in the sites were found to be normal for bottomland forests that endured two flooding events within one year.

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)

It is an unresolved paradox that non-native species are successful in novel environments whereas native species, presumably adapted to that environment, decline. This knowledge gap has persisted because third party processes in invasion ecology have been overlooked. Ungulate densities are increasing due to the eradication of predators and landscape change and I asked how herbivory and invasion might interact to cause declines of native species. In Garry oak meadows, Canada’s most endangered ecosystem, native forbs have declined relative to non-native grasses and I tested the facilitatory role of herbivory in that degradation. My investigations, novel to the field, were conducted on islands spanning the Canada-US border. Islands served as natural experimental units in a mensurative study of abundance patterns in seven plant groups and 15 focal species along gradients of herbivory, biogeography, soil depth, and human activities. Increasing ungulate densities were related to declines in abundances of native forbs, and increasing abundances of non-native annual grasses. These regional patterns were upheld by two plot-based, 2x2 factorial experiments that contrasted the fitness of native species under manipulations of herbivory and competition for light. Specifically, I showed that ungulates limited the establishment, growth, survival and reproduction of seedlings and transplanted native forbs and shrubs and that competition from non-native species had little effect. I also calculated forage selectivity indices and tested the efficacy of fencing and cutting to reduce competition, for the restoration of native community biomass. Non-native annual grasses were rarely browsed and increased with increasing ungulate density. Non-native perennial grasses declined with herbivory, however, their regional abundances were unaffected by ungulate density despite being preferentially foraged. That non-native annual and perennial grasses differed in their responses to herbivory has consequences for restoration and illustrates the challenge of developing a comprehensive theory of invasion. Reducing ungulates, necessary for the recovery of native forbs, also benefits non-native perennial grasses and therefore their removal speed recovery of Garry oak meadows. Despite advances in invasion ecology, scientists and managers are disconnected and research is rarely implemented. I conclude by proposing seven solutions to facilitate the integration of science into management.

Ecological restoration projects are considered successful when identified goals are achieved and the ecosystem progresses along a predicted successional trajectory. My study examined the progress of early-stage forest restoration projects within the Regional Municipality of Waterloo to determine the variables that affect early successional trajectories. The study was undertaken to gain further insight into the most appropriate methods to use in the evaluation of restoration outcomes and to provide some useful recommendations for restoration ecologists and practitioners. <br /><br /> Between April-October 2005 and April 2006, data were collected using a stratified random sampling technique and the wandering-quarter method to evaluate herbaceous vegetation, regenerating woody vegetation and mature trees at 7 forest restoration sites within the Regional Municipality of Waterloo. The Regional Municipality of Waterloo was selected as the study area because it has restoration projects established in forested ecosystems and the Region is typical of southern Ontario, i. e. , forest ecosystems have been disturbed by urban and agricultural activities and require ecological restoration. <br /><br /> A nested Analysis of Variance was used to test the responses of various herbaceous and woody vegetation parameters to the restoration site, restoration technique nested within the restoration site, and transects nested within the restoration technique. Site location, restoration technique, and restoration transect all appear to significantly affect restoration progress for some structural metrics. Species diversity (measured by the Shannon-Wiener Index) was significantly affected by the restoration site (p<0. 01) and transect nested within the restoration technique (p<0. 01). For some sites, differences in diversity among transects are expected to diminish as restoration proceeds and natural succession progresses. For heavily degraded sites, however, that exhibit low native plant species diversity may require a more intensive restoration strategy to improve local conditions. Density was significantly affected by the restoration site (p<0. 001) and the restoration technique nested within the site (p<0. 01). Sites without a closed forest canopy had higher densities of plants for all sampling guilds. The percentage of native species was significantly affected by the restoration site (p<0. 01) and the restoration technique nested with the site (p<0. 05). Sites that were restored from degraded forest conditions, rather than from old fields, exhibited significantly higher percentages of native plants for all sampling guilds. <br /><br /> Generally, sites with high species diversity, a high percentage of native species, and high density indicated that ecological restoration was progressing on the predicted successional trajectories and should lead to a successful restoration as time goes on. Results indicate that 4 out of 7 restoration sites are progressing as expected, i. e. , towards the predetermined restoration goal. The remaining 3 restoration sites may recover over time, but will most likely require additional restoration measures to achieve a desirable long-term outcome. At early-stages, structural measures appear to be useful indicators for evaluating the progress of restoration. In order for a restoring ecosystem to follow along an expected trajectory, formative evaluation must occur throughout the process to ensure that positive outcomes are achieved along the way. The study concludes that evaluating the progress of forest restoration projects at an early stage could greatly improve the long-term success of restoration outcomes by offering opportunities for mid-course correction and to learn from past mistakes.

Ecological restoration projects are considered successful when identified goals are achieved and the ecosystem progresses along a predicted successional trajectory. My study examined the progress of early-stage forest restoration projects within the Regional Municipality of Waterloo to determine the variables that affect early successional trajectories. The study was undertaken to gain further insight into the most appropriate methods to use in the evaluation of restoration outcomes and to provide some useful recommendations for restoration ecologists and practitioners. <br /><br /> Between April-October 2005 and April 2006, data were collected using a stratified random sampling technique and the wandering-quarter method to evaluate herbaceous vegetation, regenerating woody vegetation and mature trees at 7 forest restoration sites within the Regional Municipality of Waterloo. The Regional Municipality of Waterloo was selected as the study area because it has restoration projects established in forested ecosystems and the Region is typical of southern Ontario, i. e. , forest ecosystems have been disturbed by urban and agricultural activities and require ecological restoration. <br /><br /> A nested Analysis of Variance was used to test the responses of various herbaceous and woody vegetation parameters to the restoration site, restoration technique nested within the restoration site, and transects nested within the restoration technique. Site location, restoration technique, and restoration transect all appear to significantly affect restoration progress for some structural metrics. Species diversity (measured by the Shannon-Wiener Index) was significantly affected by the restoration site (p<0. 01) and transect nested within the restoration technique (p<0. 01). For some sites, differences in diversity among transects are expected to diminish as restoration proceeds and natural succession progresses. For heavily degraded sites, however, that exhibit low native plant species diversity may require a more intensive restoration strategy to improve local conditions. Density was significantly affected by the restoration site (p<0. 001) and the restoration technique nested within the site (p<0. 01). Sites without a closed forest canopy had higher densities of plants for all sampling guilds. The percentage of native species was significantly affected by the restoration site (p<0. 01) and the restoration technique nested with the site (p<0. 05). Sites that were restored from degraded forest conditions, rather than from old fields, exhibited significantly higher percentages of native plants for all sampling guilds. <br /><br /> Generally, sites with high species diversity, a high percentage of native species, and high density indicated that ecological restoration was progressing on the predicted successional trajectories and should lead to a successful restoration as time goes on. Results indicate that 4 out of 7 restoration sites are progressing as expected, i. e. , towards the predetermined restoration goal. The remaining 3 restoration sites may recover over time, but will most likely require additional restoration measures to achieve a desirable long-term outcome. At early-stages, structural measures appear to be useful indicators for evaluating the progress of restoration. In order for a restoring ecosystem to follow along an expected trajectory, formative evaluation must occur throughout the process to ensure that positive outcomes are achieved along the way. The study concludes that evaluating the progress of forest restoration projects at an early stage could greatly improve the long-term success of restoration outcomes by offering opportunities for mid-course correction and to learn from past mistakes.

No description available.

It is an unresolved paradox that non-native species are successful in novel environments whereas native species, presumably adapted to that environment, decline. This knowledge gap has persisted because third party processes in invasion ecology have been overlooked. Ungulate densities are increasing due to the eradication of predators and landscape change and I asked how herbivory and invasion might interact to cause declines of native species. In Garry oak meadows, Canada’s most endangered ecosystem, native forbs have declined relative to non-native grasses and I tested the facilitatory role of herbivory in that degradation. My investigations, novel to the field, were conducted on islands spanning the Canada-US border. Islands served as natural experimental units in a mensurative study of abundance patterns in seven plant groups and 15 focal species along gradients of herbivory, biogeography, soil depth, and human activities. Increasing ungulate densities were related to declines in abundances of native forbs, and increasing abundances of non-native annual grasses. These regional patterns were upheld by two plot-based, 2x2 factorial experiments that contrasted the fitness of native species under manipulations of herbivory and competition for light. Specifically, I showed that ungulates limited the establishment, growth, survival and reproduction of seedlings and transplanted native forbs and shrubs and that competition from non-native species had little effect. I also calculated forage selectivity indices and tested the efficacy of fencing and cutting to reduce competition, for the restoration of native community biomass. Non-native annual grasses were rarely browsed and increased with increasing ungulate density. Non-native perennial grasses declined with herbivory, however, their regional abundances were unaffected by ungulate density despite being preferentially foraged. That non-native annual and perennial grasses differed in their responses to herbivory has consequences for restoration and illustrates the challenge of developing a comprehensive theory of invasion. Reducing ungulates, necessary for the recovery of native forbs, also benefits non-native perennial grasses and therefore their removal speed recovery of Garry oak meadows. Despite advances in invasion ecology, scientists and managers are disconnected and research is rarely implemented. I conclude by proposing seven solutions to facilitate the integration of science into management.