| 1. |
- Bognounou, Fidèle, et al.
(författare)
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Impact of disturbance by roadwork on Pteleopsis suberosa regeneration along roadside environments in Burkina Faso, West Africa
- 2009
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Ingår i: Journal of Forestry Research. - : Springer Science and Business Media LLC. - 1007-662X .- 1993-0607. ; 20, s. 355–361-
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Tidskriftsartikel (refereegranskat)abstract
- The seedling population structure of Pteleopsis suberosa and their regeneration mechanisms were investigated in four roadside environments (graded, adjacent, intermediate and ungraded areas) along paved and unpaved roads in West Africa. A total of 203 quadrats of 2 m × 5 m in size were surveyed and placed along transects parallel to the roads. Within each quadrat, the total number of seedlings and the number of living shoots per seedling base were recorded. Regeneration mechanisms were determined by assessing basal and aerial sprouts and excavating the root systems below ground level. The results show that the total seedling density and the densities of single- and multi-stemmed individuals varied significantly (p < 0.05) among the four roadside environments. However, all seedlings were produced asexually; root suckers were predominant (98%) compared to water sprout (1%) and coppices (less than 1%). This study demonstrates that an intermediate level of soil disturbance from grading along paved and unpaved roads may stimulate P. suberosa regeneration by root suckering. Road type (paved and unpaved) did not affect seedling density, but was a highly significant variable in relation to the coppicing ability of P. suberosa populations in roadside sites. In conclusion, P. suberosa is a disturbance-tolerant species which can proliferate mainly by root suckering after roadwork disturbance.
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| 2. |
- Bognounou, Fidele, et al.
(författare)
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Informants based ethnobotany and utility evaluation of five combretaceae species : differentiation by ethnicity and geographical location
- 2011
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Ingår i: Forests, Trees and Livelyhoods. - : Taylor & Francis Group. - 1472-8028 .- 2164-3075. ; 20:4, s. 265-281
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Tidskriftsartikel (refereegranskat)abstract
- In Africa, local communities depend on forests and plants for their daily needs including goods and services. This paper describes ethnobotanical knowledge of five Combretaceae species in western Burkina Faso. Information was obtained from semi-structured interviews, direct observation and personal conversation with local experts and specialists in plant uses. Data were collected in four villages among four ethnic groups. A total of 150 specialist male and female respondents were involved and 400 users were interviewed. The data were analyzed with generalized linear models with binomial errors. The results show that there is a higher share of ethnobotanical knowledge within an ethnic/village group than between ethnic/village groups. The ethnobotanical information was classified in six main categories: food, fodder, construction materials, fuelwood, handicraft and pharmacopoeia, with the six categories except food representing important uses for all the study species. No significant difference was found for gender and age regarding the knowledge of plant species uses, which may be due to the daily life importance, and to the ecological abundance of the selected Combretaceae species.
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| 3. |
- Bognounou, Fidèle, et al.
(författare)
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Regeneration of five Combretaceae species along a latitudinal gradient in Sahelo-Sudanian zone of Burkina Faso
- 2010
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Ingår i: Annals of Forest Science. - : Springer Science and Business Media LLC. - 1286-4560 .- 1297-966X. ; 67
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Tidskriftsartikel (refereegranskat)abstract
- Seedling density and the regeneration mechanisms of five tree species, Anogeissus leiocarpa, Combretum aculeatum, Combretum micranthum, Combretum nigricans, and Pteleopsis suberosa were investigated in relation to latitudinal gradient across the Sahelo-Sudanian zone of West Africa.Data were collected on 461 quadrats (2 m x 5 m) laid out every 30 m on transect lines through Combretaceae communities at four latitudinal positions. Regeneration mechanisms were determined by excavating the below ground root system and assessing basal and aerial sprouts.The results showed a significant species x latitudinal position effect on the total density of seedling populations, and the density of single-and multi-stemmed individuals (p < 0.001). C. aculeatum and C. micranthum were abundant in the North-Sahelian sector, C. nigricans and P. suberosa in the Sudanian sector and A. leiocarpa across a wide range from the South-Sahelian to South-Sudanian sectors. In general, 58% of the seedlings were regenerated asexually (as coppice, water sprout, layer, and root sucker) while 42% were sexual recruits (as true seedling and seedling sprouts). The proportion of vegetatively propagated seedlings increased with increasing latitude for all species except C. micranthum, for which a clear decreasing trend was observed. The relative importance of the different regeneration mechanisms varied among species: seedling sprouts were important for A. leiocarpa, C. aculeatum and C. nigricans, coppice for C. micranthum and sucker for P. suberosaThe significant interaction observed between species and latitudinal position highlights the importance of accurate species-site matching to ensure successful restoration of degraded areas in the Sahelo-Sudanian zone. Inter-species differences in regeneration mechanism could be related to their biology and ecological adaptation to the site-specific biotic and abiotic factors.
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| 4. |
- Bognounou, Fidele, et al.
(författare)
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Role of climate and herbivory on native and alien conifer seedling recruitment at and above the Fennoscandian tree line
- 2018
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Ingår i: Journal of Vegetation Science. - : Wiley-Blackwell. - 1100-9233 .- 1654-1103. ; 29:4, s. 573-584
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Tidskriftsartikel (refereegranskat)abstract
- Questions: We investigated the importance of climate and herbivory on native and alien conifer colonization of the birch-dominated Fennoscandian tree line by addressing the following questions: (a) are tree line and tundra habitats similarly suitable for conifer seedling recruitment; (b) do ungulate and rodent herbivores differentially impact seedling recruitment; and (c) how does the role of habitat and herbivory on seedling recruitment vary across a marked climate gradient?Location: Northern Fennoscandia, Sweden (Vassijaure and Paddus), and Norway (Joatka and Seiland).Methods: We conducted an experiment to assess the emergence rate, survival probability and height development of Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and Siberian larch (Larix sibirica) seedlings. Three experimental plots (i.e., open control, reindeer exclosure and complete vertebrate exclosure) were established in both tree line and tundra habitats at each of the four locations. Seeds of the three conifer species were sown in each plot in June 1999 during three consecutive years. The surviving seedlings were counted in August to September 1999, 2000, 2001, 2002 and 2007. The height of all seedlings was measured in 2007.Results: Our study reveals that Norway spruce, Scots pine and Siberian larch can regenerate from seed at and above the current tree line in northern Fennoscandia. Their performance was generally higher above tree line in tundra than at tree line, but depended on species identity, climate aridity and mammal herbivory, particularly by rodents. These results suggest that the species composition and latitudinal limit of the tree line in the future might depend not only on direct effects of the future climate on the current tree line species, but also on the intensity of alien and native conifer introductions, as well as changes in herbivore populations.Conclusion: If sufficient seeds of Norway spruce, Scots pine and Siberian larch should reach the current tree line, their performances will increase with a warmer and wetter climate, and this effect will be markedly modulated by herbivores (particularly rodents). Further work is required to extend these results to determine the ability of these conifers to become tree line-forming species in the future.
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| 5. |
- Bognounou, Fidèle, et al.
(författare)
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Woody vegetation structure and composition at four sites along a latitudinal gradient in Western Burkina Faso
- 2009
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Ingår i: Bois Et Forets Des Tropiques. - 0006-579X. ; , s. 29-44
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the distribution patterns of plant species and the underlying factors is crucial to the conservation and management of plant communities in savannah-wood land ecosystems. This article describes the species composition, structure and diversity of woody species at four sites along a latitudinal gradient in the North Sahelian, South Sahelian, North Sudanian and South Sudanian sectors in western Burkina Faso. All woody species were systematically identified and measured in 82 sample plots measuring 50 x 20 m(2). Density, dominance, frequency and species and family importance values were computed to characterize the species composition. A range of diversity measures were calculated to analyze the heterogeneity of each site. A total of 74 species representing 26 families and 53 genera were found. The predominant families were Combretaceae, Mimosaceae and Caesalpiniaceae. Significant differences were found between the structural characteristics (p < 0.001) of sites and species. At some sites, the tree size-class distributions formed a reverse J-shaped curve, indicating vegetation dominated by juvenile individuals. Similarity in tree species composition between sites was found to be low, which indicates high beta diversity and reflects differences in habitat conditions, topography and between site distances. These site-specific differences highlight the importance of landscape-scale approaches in understanding species distribution pat terns, composition, structure and diversity, as well as in applying restoration and conservation measures geared to total basal area and diversity in these ecosystems.
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