Do floristic composition, plant species abundance and vegetation structure in Sudanian wetlands vary according to conservation status?

In Sahel, wetlands are particularly endangered hence practical knowledge for their sustainable management is needed. The aim of this study was to compare plant community structure between protected and unprotected wetland bank stands in eastern Burkina Faso. Phytosociological and dendrometrical parameters were carrying out in adult trees, seedling individuals and herbaceous species. Discrimination of plant communities and diversity indices were calculated for each group. Weibull distribution was used to compare the diameter structures. The results shows that plant communities located in riverbanks of unprotected wetlands have a greater specificheterogeneity. They are rich inannual speciesand in species with a wide distribution. Finally their woody stands are characterized by lower basal areas than unprotected wetland riverbank stands. Plant community stands in riverbanks of protected wetlands were better preserved but some disturbances were noticed. Furthermore, juvenile plants of the two sites were threatened and this may affect in long term, the relative stability of these trees stands as revealed by Weibull distribution. Further study should focus on wetlands riverbanks seedling status in order to propose restoration strategies

Long-Term Vegetation Change in Central Africa: The Need for an Integrated Management Framework for Forests and Savannas

peer reviewedTropical forests and savannas are the main biomes in sub-Saharan Africa, covering most of the continent. Collectively they offer important habitat for biodiversity and provide multiple ecosystem services. Considering their global importance and the multiple sustainability challenges they face in the era of the Anthropocene, this chapter undertakes a comprehensive analysis of the past, present, and future vegetation patterns in central African forests and savannas. Past changes in climate, vegetation, land use, and human activity have affected the distribution of forests and savannas across central Africa. Currently, forests form a continuous block across the wet and moist areas of central Africa, and are characterized by high tree cover (>90% tree cover). Savannas and woodlands have lower tree cover (<40% tree cover), are found in drier sites in the north and south of the region, and are maintained by frequent fires. Recent tree cover loss (2000–2015) has been more important for forests than for savannas, which, however, reportedly experienced woody encroachment. Future cropland expansion is expected to have a strong impact on savannas, while the extent of climatic impacts depends on the actual scenario. We finally identify some of the policy implications for restoring ecosystems, expanding protected areas, and designing sustainable ecosystem management approaches in the region

ANTIPLASMODIAL TRITERPENOIDS ISOLATED FROM CANTHIUM MULTIFLORUM

In Burkina Faso, roots of Canthium multiflorum (Thonn.) Hiern (Rubiaceae) are used for the treatment of malaria and hypertension [1]. This investigation was initiated because of the absence of published phytochemical reports on this specie and the possibility of the presence of antiplasmodial compounds. A bioactivity guided fractionation of roots of Canthium multiflorum led to the isolation of the 2 new ursenoic acid derivatives, 19α-hydroxy-3-oxo-ursa-1,12-dien-28-oic acid 1 and 3-oxo-15α,19α-dihydroxyursa-1,12-dien-28-oic acid 2 which were tested for antiplasmodial effect and for inducing change of the shape of membranes of erythrocytes. Assay for antiplasmodial activity was performed using chloroquine-sensitive Plasmodium falciparum strain 3D7 [2]. Chloroquine was used as a positive control. Investigation of membrane shape effects of pentacyclic triterpenes was performed according to a previous described method (Ziegler et al., 2002) [3]. The structure of the two new compounds was elucidated using MS and NMR spectroscopy. The HR-ESI-MS gave a m/z 467.3161, calcd. for C30H43O4 (M-H)- 467.3167 for 1 and m/z = 507.3089 [M+ Na]+ (calcd. for C30H44NaO5 :507.3081) for compound 2. Application of the modified octant rule and comparison of the recorded CD spectrum with those of related pentacyclic triterpenoids with a 1-en-3-one system in the A-ring confirmed the absolute configuration of the two compounds. A moderate antiplasmodial activity (IC50=26 μg/ml) was observed which was not related to the deformation of the shape of erythrocyte membranes. References 1. Nacoulma, O.G. (1996). Plantes médicinales et pratiques médicinales traditionnelles au Burkina Faso: Cas du plateau central. Faculté des Sciences et Techniques, Université de Ouagadougou. 2. Ziegler, H.L., Staerk, D., Christensen, J. et al. (2002b). Antimicrobial Agents and Chemotherapy, 46, 1441–1446. 3. Ziegler, H.L., Jensen, T.H., Christensen, J., Staerk, D. et al. (2002a). Planta Medica, 68, 547–549. Acknowledgments: This work was supported by Danida. We thank Dorte Brix for technical support

Potent antiproliferative cembrenoids accumulate in tobacco upon infection with Rhodococcus fascians and trigger unusual microtubule dynamics in human glioblastoma cells.

Though plant metabolic changes are known to occur during interactions with bacteria, these were rarely challenged for pharmacologically active compounds suitable for further drug development. Here, the occurrence of specific chemicals with antiproliferative activity against human cancer cell lines was evidenced in hyperplasia (leafy galls) induced when plants interact with particular phytopathogens, such as the Actinomycete Rhodococcus fascians.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe