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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

EXOTIC INVASIVE PLANTS IN KENTUCKY

Liang, Yu 01 January 2010 (has links)
Invasion of exotic species is a significant problem in natural ecosystems, reaching epidemic proportions and resulting in significant economic losses. However, insufficient knowledge of explicit spatial distribution of invasive species hinders our ability to prevent and/or mitigate future invasion. In this study, we demonstrate the use of existing voluntary data to survey invasive plant species in Kentucky. We also reconstructed the historical distribution of 16 exotic invasive plants typical to Kentucky using herbarium records. We found that Kentucky is facing a large threat from exotic invasive plants as they are reported throughout most counties. The distribution maps for four of the top 10 most reported invasive species revealed that Kentucky is presently or was previously a front of invasion. The majority of the 16 targeted invasive species were scattered throughout Kentucky with no concentrations within particular regions. Cumulative curves of occupied counties over time fit a “J” shape expansion curve, which indicates the potential for further future invasion. This study demonstrates the usefulness of voluntary data and herbarium data to reconstruct the historical and current distribution of invasive species. Further studies on other invasive species can take advantage of information associated with herbarium specimens to achieve more fruitful results.
2

Contribution de la glyptique à l'étude de la grande faune en Syrie aux 4ème et 3ème millénaires

Devillers, Anne 28 May 2018 (has links)
L’étude entreprise visait à examiner l'apport que l'iconographie peut fournir à l’étude de la grande faune mammalienne et à l'évaluation de sa distribution historique au Proche-Orient, en prenant le 4ème et le 3ème millénaire en Syrie du nord comme époque et région cible. Trois objectifs précis étaient posés dans ce cadre (1) Proposer à travers des sources glyptiques contemporaines une vue de la faune des 4ème et 3ème millénaires en Mésopotamie du Nord ;(2) Evaluer la cohérence de cette image par rapport aux données archéozoologiques et par rapport à un modèle géochronologique plus large de l’évolution de la faune régionale ;(3) Evaluer la pertinence de la glyptique comme marqueur pour l’étude de la paléofaune. The object of this study was to examine the contribution that iconography can make to the study of large mammal faunas, focussing on the 4th and 3rd millennia in Upper Mesopotamia (Syria). Three goals were set in this framework (1) To propose a view of 4th and 3rd millennia fauna in Upper Mesopotamia as seen through glyptic sources; (2) To evaluate the coherence of this view in relation to contemporary archaeozoological data and in relation to a wider geochronological model of the regional fauna; (3) To assess the relevance of glyptic as a marker in the study of ancient faunas. / Doctorat en Histoire, histoire de l'art et archéologie / info:eu-repo/semantics/nonPublished

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