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dc.contributor.advisorBuckland, S. T. (Stephen T.)
dc.contributor.advisorMagurran, Anne E.
dc.contributor.advisorIllian, Janine
dc.contributor.authorStudeny, Angelika C.
dc.description.abstractThe global loss of biodiversity calls for robust large-scale diversity assessment. Biological diversity is a multi-faceted concept; defined as the “variety of life”, answering questions such as “How much is there?” or more precisely “Have we succeeded in reducing the rate of its decline?” is not straightforward. While various aspects of biodiversity give rise to numerous ways of quantification, we focus on temporal (and spatial) trends and their changes in species diversity. Traditional diversity indices summarise information contained in the species abundance distribution, i.e. each species' proportional contribution to total abundance. Estimated from data, these indices can be biased if variation in detection probability is ignored. We discuss differences between diversity indices and demonstrate possible adjustments for detectability. Additionally, most indices focus on the most abundant species in ecological communities. We introduce a new set of diversity measures, based on a family of goodness-of-fit statistics. A function of a free parameter, this family allows us to vary the sensitivity of these measures to dominance and rarity of species. Their performance is studied by assessing temporal trends in diversity for five communities of British breeding birds based on 14 years of survey data, where they are applied alongside the current headline index, a geometric mean of relative abundances. Revealing the contributions of both rare and common species to biodiversity trends, these "goodness-of-fit" measures provide novel insights into how ecological communities change over time. Biodiversity is not only subject to temporal changes, but it also varies across space. We take first steps towards estimating spatial diversity trends. Finally, processes maintaining biodiversity act locally, at specific spatial scales. Contrary to abundance-based summary statistics, spatial characteristics of ecological communities may distinguish these processes. We suggest a generalisation to a spatial summary, the cross-pair overlap distribution, to render it more flexible to spatial scale.en_US
dc.publisherUniversity of St Andrews
dc.subjectDiversity measuresen_US
dc.subjectGoodness-of-fit statisticsen_US
dc.subjectSimpson's indexen_US
dc.subjectShannon indexen_US
dc.subjectGeometric meanen_US
dc.subjectBritish breeding birdsen_US
dc.subjectCross-pair overlap distributionen_US
dc.subjectPoint patternen_US
dc.subjectDetection probabilityen_US
dc.subject.lcshBiodiversity--Statistical methodsen_US
dc.subject.lcshGoodness-of-fit testsen_US
dc.subject.lcshBird populations--Estimates--Great Britain--Case studiesen_US
dc.titleQuantifying biodiversity trends in time and spaceen_US
dc.contributor.sponsorUniversity of St Andrews.en_US
dc.contributor.sponsorNational Centre of Statistical Ecology (NCSE)en
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US
dc.publisher.departmentCentre of Research into Ecological and Environmental Modelling, School of Mathematics and Statisticsen_US

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