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Olwen M. Grace Oscar A. Pérez-Escobar Eve J. Lucas Maria S. Vorontsova Gwilym P. Lewis Barnaby E. Walker Lúcia G. Lohmann Sandra Knapp Peter Wilkie Tiina Sarkinen Iain Darbyshire Eimear Nic Lughadha Alexandre Monro Yannick Woudstra Sebsebe Demissew A. Muthama Muasya Sandra Díaz William J. Baker Alexandre Antonelli 《Trends in plant science》2021,26(5):433-441
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Sebsebe Demissew 《Nordic Journal of Botany》1989,8(6):627-630
Two new species, Chascanum sulcatum and C. obovatum are described and illustrated, one occurring in Ethiopia and Somalia, the other in Ethiopia and N Kenya. 相似文献
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Menassie Gashaw A. Michelsen I. Friis M. Jensen Sebsebe Demissew Zerihun Woldu 《Nordic Journal of Botany》2002,22(1):19-33
Regeneration mechanisms of vegetation and the role of tree bark resistance to frequent fire were studied in savanna woodlands and grasslands in Gambella, Western Ethiopia. Data were collected from four sites, each with three replicate plots. The variation between sites in species composition and biomass correlated with the differences in fire intensity. Foliar cover was recorded for individual plant species regenerating by sprouting from older parts of plants that had survived fire or by seedlings; records were made during the dry season and at the beginning of the wet season. Data on bark thickness and tree diameters of 12 dominant tree species were also recorded. Both facultative and obligate sprouters significantly contributed to post‐fire recovery, comprising 98.5 % of total vegetation cover. The contribution of seedlings to cover and abundance immediately following fire was negligible, but seedling density increased in the beginning of the rainy season, 4 to 5 months after fire. The importance of the sprouting and seeding strategies varied between the different plant growth forms. The highest contribution to cover and frequency was made by the most abundant grass species, which reproduced in both ways. Facultative sprouters made up 67.3 % of the vegetation cover, out of which 54 % consisted of grasses. Broad‐leaved herbs and trees/shrubs regenerating mainly by sprouting made up 31.3 % of the vegetation cover. Adaptations to fire in tree species seemed to include the development of a thick bark, once the tree has passed seedling stages. Tree bark thickness and tree diameter at breast height were strongly correlated with the time taken for cambium to reach an assumed lethal temperature of 60°C when exposed to fire, which indicated that mature trees with thick barks might resist stronger fire better than, e.g., small or young trees and trees with thin bark. However, for a given bark thickness the cambium resistance to heat varied three‐fold among species. Hence, site differences in fire intensity seemed to influence the distribution of trees depending on their bark characteristics and resistance to fire. 相似文献
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Dorothea Bedigian Sebsebe Demissew Paul Gepts Daniel F. Austin Neil A. Harriman John Klock Sarah Walshaw John Richard Stepp Beverly J. Brown Julie Polley David Winston Barbara Pickersgill Patrick Van Damme Nina L. Etkin Beronda L. Montgomery Linda Perry Stephen E Siebert Robert J. Krueger Kathleen McConnell Wendy Applequist Mary Theresa Bonhage-Freund Karol Chandler-Ezell 《Economic botany》2005,59(4):395-412
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Phylogeography of the wild and cultivated stimulant plant qat (Catha edulis,Celastraceae) in areas of historical cultivation 下载免费PDF全文