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Accueil du site → Doctorat → Royaume-Uni → 2005 → Effect of drought on growth and development of perennial desert species for rehabilitation of degraded areas of Kuwait

University of Reading (2005)

Effect of drought on growth and development of perennial desert species for rehabilitation of degraded areas of Kuwait

Madouh, Tareq A.

Titre : Effect of drought on growth and development of perennial desert species for rehabilitation of degraded areas of Kuwait

Auteur : Madouh, Tareq A.

Université de soutenance : University of Reading

Grade : Doctor of Philosophy (Ph.D.) : 2005

Résumé
This research focused on a small range of desert perennials native to Kuwait (Farsetia aegyptia, Lycium shawii, Cenchrus setigerus and Calligonum polygonoides) and determined their responses to stresses typical of degraded arid ecosystems. All experiments were conducted under controlled environmental conditions to minimise variation due to confounding factors. Comparisons of seed germination showed that seeds of Farsetia and Lycium germinated at lower osmotic potential levels (up to -1.5 MPa) compared to other species. Studies on more mature plants indicated that Farsetia and Lycium appeared to regulate water loss primarily via stomatal closure, with reductions in leaf water potential and relative water content only occurring later, Farsetia also appeared to alter osmotic potential to minimise water loss during more severe drought. During drought, proportionally more resources were allocated to root development than shoot growth in Farsetia, whereas Cenchrus showed reduced root growth. High temperatures and drought reduced growth and prevented flower initiation of Farsetia. Clipping, while mimicked grazing, had a negative impact on the shoot and root growth of Farsetia regardless of the moisture conditions and even after relief from drought. In contrast, Cenchrus growth was affected to a greater extent by drought than clipping. Response to applied nitrogen and different irrigation regimes varied, Cenchrus demonstrating enhanced growth, whereas there was little influence on Farsetia. These small-scale experiments demonstrate some of the possibilities for successful re-establishment of native species in Kuwait. Practical management strategies and constructive conservation plans are now required to sustain the existing natural vegetation, encourage regeneration and minimise the impacts of grazing within the rangeland of Kuwait.

Présentation : EThOS (UK)

Accès au document : Proquest Dissertations & Theses

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