Thesis (M.Sc.)--York University, 2006. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 63-70). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR19691

Berlin, Techn. Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Berlin, Techn. Univ., Diss., 2003. / Computerdatei im Fernzugriff.

Duisburg, Essen, Universiẗat, Diss., 2004.

published_or_final_version / abstract / toc / Botany / Master / Master of Philosophy

No description available.

Quantifying the pattern and magnitude of spatio-temporal variation in demography, and identifying underlying causes, is key to understanding population dynamics. Using long-term, spatially-explicit data from a small population of European Starlings (Sturnus vulgaris) on Fair Isle, Scotland, I quantified spatio-temporal variation in demography and investigated its underlying mechanisms. I objectively described the population’s physical structure and hence defined spatial clusters of nest sites at multiple spatial scales. I quantified spatio-temporal variation in reproductive success and survival, across clusters and years. I explicitly included multiple broods in these analyses, examining their effects on variation in reproductive success and pre-breeding survival. My results demonstrate substantial small-scale spatial variation in both reproductive success and adult survival, contesting the common assumption that demography will be spatially homogeneous at small scales within populations that lack obvious subdivision. The inclusion of second broods had a substantial effect on spatio-temporal variation in reproductive success, however, the pre-breeding survival of second-brood individuals was so low that ultimately they may not have a large effect on population dynamics. I quantified dispersal movements of colour-ringed individuals, demonstrating that individuals breed significantly closer to their natal site than expected under random settlement. Individuals that left their natal cluster to breed moved to less productive clusters more than expected, and the difference in productivity between natal and breeding clusters did not vary with the number of available nest sites in the breeding year. The absence of nest-site availability effect suggests such patterns are consistent with source-sink dynamics, rather than site-dependent population regulation. Finally, I quantified the effect of grassland availability on demographic variation, since reduction in grassland is postulated to be a major factor in starling decline across Europe. However, there was no significant effect of the proportion of grassland surrounding the nest site on reproductive success or subsequent survival.

Prostrate juniper heath (H15 <I>Calluna vulgaris-Juniperus communis </I>subspecies <I>nana </I>heath) is of considerable conservation importance. Its infrequent distribution in northwest Scotland is often attributed to historical burning. The intraspecific taxonomy of <I>Juniperus communis </I>L (Cupressaceae) is unclear. This thesis seeks to understand the history and current status of the community, and to clarify the taxonomy of juniper in Scotland. The impact of current levels of land use on extant HI5 was found to be low. A study of the environmental conditions associated with HI5 revealed that the community was absent from large areas of north-west Scotland with suitable conditions. Other communities with only infrequent juniper exist in many such areas. Sites with environmental conditions suitable for HI5 were investigated using palaeoecological methods. Fire had occurred in both HI5and non-H15 sites, but there was a prolonged recent absence in HI5. A study of annual growth rings showed juniper in HI5 to be twice as old as in other communities, emphasising the lack of recent disturbance. Evidence of greater past juniper cover was not found on non-H15 sites. It is argued that the history of prostrate juniper heath is more dynamic and complex than previously believed. Comparative morphological, genetic marker, and reciprocal transplant studies of juniper populations showed that <I>Juniperus communis </I>ssp. <I>nana </I>is characterised by genotypic prostrateness, imbricate leaf arrangement, and abrupt leaf tips. It is argued that the conservation importance of HI5 and juniper are increased by the findings of this study. Implications for conservation practice, and future research, are considered.

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Berlin, Techn. Univ., Diss., 2001. / Computerdatei im Fernzugriff.