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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

Aspects of the ecology and conservation of the rare plant species Phyteuma spicatum L (Campanulaceae) in the British Isles

Wheeler, Belinda Ruth January 1997 (has links)
No description available.
2

Understanding the causes of reproductive failure in two rare Scottish plants, Linnaea borealis L. and Spiranthes romanzoffiana Cham. and the implications for future conservation management

Scobie, Andrew Rutherford. January 2009 (has links)
Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on Feb. 23, 2010). Includes bibliographical references.
3

The reproductive biology and conservation of the endangered Hawaiian legume, Sesbania tomentosa, with emphasis on its pollination system

Hopper, David R. January 2002 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2002. / Includes bibliographical references (leaves 181-215). Also available on microfiche.
4

Understanding the causes of reproductive failure in two rare Scottish plants, Linnaea borealis L. and Spiranthes romanzoffiana Cham. and the implications for future conservation management

Scobie, Andrew Rutherford January 2009 (has links)
The pollinator spectrum, diversity of flower colour, natural pollination and fruit set levels were examined in Scottish <i>L. borealis </i>patches.  Flowers were visited by a diverse spectrum of insect pollinators but, despite high natural pollination levels, fruit set was very low in the majority of patches examined.  The breeding system of <i>L. borealis </i>was confirmed as highly self-incompatible and limited compatible mate availability was identified as the cause of reproductive failure.  Due to the limited pollen dispersal capabilities of flies which dominate the pollinator spectrum, isolation from pollen exchange between compatible mates began at very short distances.  A diversity of compatible mates situated within close proximity (&lt;6 m) was shown to be the key requirement for high natural fruiting success in <i>L. borealis.  </i>Cross-pollination between neighbouring <i>L. borealis </i>patches resulted in high fruiting success suggesting that transplantation of compatible mates into isolated patches could restore their reproductive success. Natural pollination levels were generally high on Colonsay and a very low, but consistent, level of capsule and seed set was recorded in most years.  Capsules produced by Colonsay plants contained very low quantities of seed (&lt;100/capsule) and high numbers of empty testa, and seed set was extremely low (&lt;1%).  Severe reproductive failure was evident and the cause was attributed to self-incompatibility and/or inbreeding depression.  Seed set was also very low for all of the crosses made within Scotland, even between the two distinct genetic groups.  The high levels of seed set achieved following crossing of Scottish and North American plants suggest that restoration of reproductive success in Scotland may require the introduction of some North American genes.
5

Rarity and conservation of Melampyrum sylvaticum

Dalrymple, Sarah January 2006 (has links)
<i>Melampyrum sylvaticum</i> (small cow-wheat) is a hemiparasitic annual of boreal-montane regions of Europe.  The Species Action Plan recommended that in addition to protecting extant populations, by 2010 there should be an additional five populations that have been created with the aim of enhancing greater genetic diversity of the species.  Consequently this project was set up in order to provide the ecological knowledge required to meet such targets. There are various management options available to conservationists looking to prevent <i>Melampyrum sylvaticum’s</i> extinction from the UK but from the results of this project it is clear that some methods have drawbacks that should preclude their use.  Population augmentation with seeds from other populations is not advised due to the risk of genetic ‘swamping’ or outbreeding depression.  Seed amplification would avoid these problems but may introduce different complications by artificially promoting certain genotypes within a population. Population expansion by mimicking ant dispersal is recommended as a way of minimizing density dependent mortality in larger populations but is not suitable in smaller populations. Seed translocation to unoccupied sites is therefore, the best option but the exact details of seed-sourcing and sowing should be guided by the results of the Species Recovery Project in order to avoid predicted limitations. The long-term outlook for <i>M. sylvaticum</i> will depend entirely on whether populations can be created that operate as part of a functioning ecosystem (including pollinating and seed-dispersing insects) with enough demographic and genetic stability to survive predicted climate change.
6

The influence of beaver impoundments on vegetative composition, and modeling habitat suitability as a tool for wildlife management and conservation

Bonner, Jerri LeAnne. January 2005 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 119 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references.
7

Botanising in Linnaean Britain : a study of Upper Teesdale in northern England

Horsman, Frank January 1998 (has links)
The Swede, Carl Linnaeus (1707-1778), introduced an artificial " Sexual System " of plant classification in 1735, and a binomial system of nomenclature in 1753. They made plant identification much easier. The Linnaean period in Britain lasted from 1760 until [1810-]1830. It is demonstrated that it was during this period that it was first recognised that an unusually high number of rare plants grow in Upper Teesdale. Most of the rare plants of the then very remote Upper Teesdale were discovered shortly after 1783 by William Oliver (1760-1816), alone. He was a surgeon and part of a medical dynasty. How he became a botanist, with his medical background, is examined in detail. He trained at Edinburgh but did not do botany. However, he knew John Hope, the Professor of Botany. Hope was one of only two people teaching the Linnaean system in Britain at this time. The appearance of Linnaean floras of Britain in English from the 1770's onwards made field botany accessiblet o anyone. Previously complex natural systems of plant classification and the use of Latin had restricted access. How Oliver's discoveries were made known is examined in detail. It involved Rev. John Harriman (1760-183 1) who was influenced by the Linnean Society of London, formed in 1788, and the Linnaean English Botany which began in 1790. H-e wanted to become a Fellow of the Linnean Society. James Edward Smith was President of the Linnean Society and an author, with James Sowerby, ofEnglish Botany. IV alic, ,j Lrf Edward Robson (1763-1813), a Quaker botanist and already an Associate of the Linnean Society, and his compilation: Plantae rariores agro Dunelmensi indigenae of 1798, and John Binks (1766-1817), an artisan botanist. Medicine made botanists of both Harriman and Binks, as well as Oliver. Linnaeus influenced the teaching of materia medica (the plant simples).
8

A simple GIS approach to predicting rare plant habitat north central Rocky Mountains, United States Forest Service, Region One /

Nock, Erin Elizabeth. January 2008 (has links)
Thesis (M.A.)--University of Montana, 2008. / Title from title screen. Description based on contents viewed Aug. 27, 2008. Includes bibliographical references (p. 46-51).
9

Population biology of rare mariposa lilies (Calochortus: Liliaceae) endemic to serpentine soils in southwestern Oregon /

Fredricks, Nancy Ann. January 1992 (has links)
Thesis (Ph. D.)--Oregon State University, 1993. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
10

Environmental limitations of two rare Atlantic Coastal Plain flora species and the impact of hydrological alterations /

Lusk, Jennifer Mary-Jane. January 1900 (has links)
Thesis (M.Sc.)--Acadia University, 2006. / Includes bibliographical references (leaves 125-134). Also available on the Internet via the World Wide Web.

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