Herbaceous plants are found everywhere. However, they are very little studied. The general objective of this study is to improve knowledge of the herbaceous flora introduced from Côte d’Ivoire. The methodology used to draw up the list of exotic woody plants of Côte d’Ivoire consisted of a bibliographic synthesis. Thus, published works and articles as well as national, regional and international online databases were consulted. In total, 550 introduced and naturalized herbaceous plants belonging to 345 genera and divided into 101 families were identified. The dominant genera are: Heliconia and Solanum, Crotalaria and Euphorbia. The most predominant families are: Fabaceae, Poaceae, Compositae, Solanaceae and Araceae. Introduced herbaceous plants are dominated by nanophanerophytes with 242 species (44%). These are most terrestrial dicotyledonous angiosperms. They are mainly (67%) perennial. Regarding morphological types, the introduced herbaceous plants are subdivided into 477 erect plants (87%) and 73 lianas (13%). 44 species with conservation value have been identified in their area of origin, i.e. 8% of all species. Forty-two (42) species are endemic to several countries including: Brazil, India, Mexico and Madagascar. Seven (07) species are present on the IUCN red list (2024). These are: 2 critically endangered species (CR), 03 endangered species (EN) and (02) vulnerable species (VU). The majority of introduced herbaceous plants come from the Americas (41%) and Asia (23%).
The present study aims to improve knowledge of the resilience of post-cultivation vegetation in the Ivorian sub-Sudanese sector by discriminating the stages of post-cultivation reconstitution and characterising these stages using the structural attributes and functional traits of the species.
To this end, 4 groups corresponding to the different stages of reconstitution were identified. These stages are divided into three groups according to their characteristics. Stage_1 is characterised by SudanoZambézian (SZ) and introduced (i) species, generally hemicryptophyte-pyrophytic and chamaephytes that spread by anemochory and barochory. Stage_2 is characterised by Guinean-Congolian and Sudano-Zambézian transition species and Sudano-Zambézian species. They are therophytes and nanophanerophytes, anemochores with small leaves (nanophyll, leptophyll and microphyll). Stages 3 and 4 share the same characteristics. They are characterised by GC species, which are generally large (mesophanerophytes and megaphanerophytes) as well as geophytes, which have large leaves (megaphyll) and spread by zoochory (epizoochory and endozoochory).
In short, post-cultivation reconstitution takes place in four stages. These stages are divided into four groups according to their characteristics. Depending on the maturity gradient, these stages are marked by a transition from savannah species, herbaceous species with small leaves and anemochorous spread, to forest species, large species with large leaves and zoochorous spread.
Biological invasions have many impacts on the composition of flora and soil chemistry. In this study, we analyzed the impacts of an invasive exotic plant, Chromolaena odorata on the floristic diversity and the physico-chemical composition of the soil of the Banco National Park. For this, we compared the floristic and physicochemical parameters of 4 biotopes: forests, ruderal zones without C. odorata, ruderal zones with a young C. odorata invasion and ruderal zones with an old invasion of C. odorata. Floristic inventories and soil samples of 0-20 cm depth were made in quadrats of 4 m2 (2 m x 2 m) of each biotope. A total of 36 quadrats were placed due to 9 repetitions per biotope. The results showed that: Floristically, the ruderal areas with an old invasion of C. odorata had a low floristic richness and a low floristic diversity. In addition, the abundance of native species in these areas was reduced. At soil level, 5 chemical minerals showed significant differences. There are: organic carbon, hydrogen, exchangeable potassium, exchangeable sodium and humus. Our results also showed that areas invaded by C. odorata consume exchangeable potassium as they increase the exchangeable sodium concentrations in soils. Consequently, these two minerals could play an important role in the growth and colonization of environments by C. odorata to the detriment of native plants. Furthermore, ruderal areas with old C. odorata invasion were rich in chemical minerals unlike other biotopes.