School of Botany - Theses
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ItemThe value of revegetated linear strips and patches of habitat for faunal conservation: reconciling ecological and landholder perspectives( 2012)A large-scale loss of biodiversity is currently occurring around the world, and it has been argued that extensive restoration of the landscape is necessary to reduce species extinctions. I assessed the effectiveness of revegetation for maintaining reptile (Reptilia) and beetle (Coleoptera) communities in two fragmented, agricultural landscapes of south-eastern Australia, and investigated how the management actions of landholders influenced the composition and structural attributes of revegetated and remnant areas. Reptiles and beetles were surveyed using pitfall traps from January to March in 2008 and 2009. I established the variation in reptile and beetle species richness and abundance in remnant, revegetated and cleared linear strips, in remnant patches of vegetation and in revegetated areas adjacent to the remnant patches. Habitat variables such as rock cover and the proportion of native plants were also recorded. In order to determine landholders’ past and planned revegetation activities, the composition of plantings, and their attitudes towards and intentions to manage revegetated and remnant areas, I quantitatively surveyed 400 landholders using postal questionnaires. I then used Bayesian Networks to integrate the ecological and social data I collected and demonstrate the conceptual link between management actions and biodiversity outcomes. Overall I found that reptile and beetle species richness, abundance and community composition did not substantially differ between revegetated, remnant, and cleared linear strips; revegetated and remnant patches; or between revegetated linear strips and revegetated patches. However, I found some reptile and beetle species showed a trend towards higher abundance in remnant linear strips than in revegetated and cleared linear strips. Interestingly, species richness and abundance of rare reptiles, overall reptile abundance, and abundance of Carlia tetradactyla increased in remnant linear strips but decreased in revegetated and cleared linear strips as distance from remnant patches increased. Reptile species richness and abundance were positively influenced by rock cover, and reptile and beetle community composition was substantially influenced by environmental variables such as rock, litter and herb cover. Three-quarters of survey respondents had previously undertaken revegetation on their land, the majority of them having replanted with native trees and shrubs along linear strips. Respondents that had revegetated or planned to revegetate were usually Landcare members with an off-farm income. Landholder attitudes towards revegetated and remnant areas influenced their intention to manage these areas, with landholders who considered replanted and remnant areas to be detrimental to their property most likely to undertake management actions such as pest control. Using Bayesian Networks, I determined that the management actions of landholders were more likely to increase reptile and beetle species richness in cleared linear strips than in other linear strips and patches. The most cost-effective management actions for increasing reptile and beetle species richness were weed control, planting trees and shrubs and adding leaf litter and fallen timber/coarse woody debris. The agricultural landscapes I studied are highly degraded, and the remaining reptile and beetle species are mostly a robust subset of previously present species, with species requiring good quality ground layers persisting along remnant linear strips. Bayesian Networks are an effective tool for integrating ecological and social data to inform management decisions, and increase the value of revegetation for wildlife.
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ItemDiversity and systematics of Peyssonneliaceae (Rhodophyta) from Vanuatu and southeastern Australia( 2010)The thesis investigates members of the crustose and largely calcified red algal family Peyssonneliaceae through molecular analyses and anatomical and ultrastructural observations. Mitochondrial CO1 DNA barcoding was implemented, in combination with fine-scale anatomy, to recognise species boundaries and identify complexes of cryptic species. Nuclear and organellar DNA markers were employed to construct a multigene phylogeny for Vanuatu and southern Australian members of the family facilitating the recognition of two undescribed genera Annea and Incendia.