Since the outbreak in December 2019, in Wuhan (China) of COVID-19, approved drugs are still lacking and the world is seeking effective treatment. The purpose of this article is to review the medicinal plants with potential to be used as complementary therapies against COVID-19. Bibliographic information was searched in several databases (Google Scholar, PubMed, Scopus, ScienceDirect, PROTA, ResearchGate and GLOBEinMED), to retrieve relevant papers on (1) plants used to manage common symptoms of COVID-19, (2) plant secondary metabolites with confirmed inhibitory effects on COVID-19 and (3) plants exhibiting pharmacological activities of relevance for COVID-19 management. A total of 230 species was recorded as potential source of ingredients for the fight against the 2019 novel corona virus. Of these species, 30 contain confirmed antiCOVID-19 secondary metabolites, 90 are used traditionally to manage at least 3 common symptoms of COVID-19, 10 have immunostimulant activity, 52 have anti-inflamatory activity, 14 have antiviral properties and 78 species are documented as used to treat malaria. A PCA analysis showing cluster formatting among the recorded species indicates 4 groups of species and an array of possibility of using individual species or a combination of species for their complementary effects. The authors argue that Cameroonian medicinal plants can be of potential contribution to the fight against COVID-19. Further applied research is needed to provide more scientific evidence for their efficacy, to establish standard formulations and clinical studies as part of efforts to develop therapies for COVID-19.

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This study was carried out in the classified forest of Djoli-Kera found in the SouthEastern part of Chad. It aimed to analyze the spatial and temporal dynamics of land cover between 1972 and 2013 and to determine the drivers of vegetation degradation. The databases used were made up of 4 Landsat satellite images (1MSS of 1972, 5TM of 1984, 7ETM+ of 1990 and 2010) and a spot 6 image of 2013, supplemented by field studies. Satellite images were processed using ENVI and ArcGIS software. Interview was used to identify the activities carried out by the local population. In 1972, the classified forest consisted of four types of land cover, the most important of which was open forest (51%), followed by wooded savannah (26%), tree savannah (21%) and sparse vegetation consisting of farms and fallows (2%). Gradually open forest and tree savannah disappeared. In 2013, the main types of land cover were shrub savannah (40%), sparse vegetation (28%), wooded savannah (12%), bare soil (12%) and dwellings (8%). Livestock, agriculture, wood collection and bushfires are perceived by local population as main drivers of forest cover change. Awareness-raising, monitoring and regulation of access to resources must be pursued, but also managers of the classified forest must accompany the local populations in the planting of trees and the setting up of more efficient farming systems to reduce pressure on the forest's resources.

This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM þ of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon (250.75 t C ha À1 ). This value has decreased by more than 60% for mixed crop farms (94.67 t C ha À1 ), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest. ARTICLE HISTORY

In order to find strategies for sustainable management of resources, a study was carried out on the analysis and management of stands of Gnidia glauca in the Kilum-Ijim region (North-West Cameroon). All individuals were identified and counted in 33 plots of 40mx40m established between 1963 and 2785 m altitude in these Gnidia glauca formations. The height and diameter of each individual were measured. A quadrat of 1m² was established around the mature trees to evaluate the regeneration. ANOVA was used to compare the average density of the species in various plots and the DUNCAN test at the 5% significance level (SPSS software version 17.0) was used to separate these means. It emerges from this study that the Thymelaeaceae (G. glauca) family is mainly represented. The Asteraceae, Rubiaceae, Poaceae and Fabaceae are the most diverse families in these formations. The distribution of individuals of G. glauca in diameter classes shows a decreasing pattern. The low density of G. glauca is observed at low altitudes (166.66 stems / hectare), and the high density is between 2350 and 2450 m (778.18 stems / ha). The average standing densities of G. glauca varies between 64.58 and 459.37 stems per hectare; these values indicate a good regeneration of this species in European Scientific Journal February 2017 edition vol.13, No.6 ISSN: 1857

Since the outbreak in December 2019 in Wuhan (China) of COVID-19, approved drugs are still lacking and the world is seeking effective treatment. The purpose of this article is to review the medicinal plants with potential to be used as complementary therapies against COVID-19. Bibliographic information was searched in several databases (Google Scholar, PubMed, Scopus, ScienceDirect, PROTA), to retrieve relevant papers on (1) plants used to manage common symptoms of COVI-19, (2) plant secondary metabolites with confirmed inhibitory effects on COVI-19 and (3) plants exhibiting pharmacological activities of relevance for COVID-19 management. A total of 230 species was recorded as potential source of ingredients for the fight against the 2019 novel corona virus. Of these species, 30 contain confirmed antiCOVID-19 secondary metabolites, 90 are used traditionally to manage at least 3 common symptoms of COVID-19, 10 have immunostimulant activity, 52 have anti-inflamatory activity, 14 have antiviral properties and 78 species are documented as used to treat malaria. A PCA analysis showing cluster formatting among the recorded species recorded indicates 4 groups of species and an array of possibility of using individual species or combination of species for their complementary effects. The authors argue that Cameroonian medicinal plants can be of potential contribution to the fight against COVID-19. Further applied research is needed to provide more scientific evidence for their efficacy, to establish standard formulations and clinical studies as part of efforts to develop therapies for COVID-19.

One of the forms of forest management is community forestry which is as an alternative to state-managed conservation. Knowledge of the wood potential and exploitable species is a prerequisite for the sustainable management of a community forest. This study carried out in the Cobaba community forest in Eastern Cameroon aimed to assess the floristic diversity and exploitable potential of timber species. A floristic inventory at a sampling rate of 8% was carried out and the volume of trees having reached the minimum exploitable diameter estimated. A total of 7736 commercial trees with dbh !20 cm were recorded, belonging to 65 species, 58 genera and 26 families. The Shannon-Weaver diversity index (H 0) was 3.61. The density was 42.04 stems ha-1 and the basal area 16.43 m 2 ha À1. A volume of timber of 31,929.21 m 3 has been estimated for trees having reached the minimum exploitable diameter. About 30% of this volume is made up of high and medium commercial value species for which market demand exists. The most abundant species of high commercial value were Triplochyton scleroxylon, Entandrophragma cylindricum, and Milicia excelsa. For sustainable management and species conservation, we recommend that species with very low densities should be excluded from logging and for each species exploited, some well-conformed seed trees with a diameter greater than the minimum exploitable diameter should be left to ensure the renewal of the wood resource.