The present study was carried out to improve knowledge on the preferential environments for invasion of C. odorata with a view to combating the species. Four biotopes were selected: closed forests, ruderal areas without C. odorata (by the side of roads, under wires), ruderal areas with a young invasion of C. odorata (populations invaded by young C. odorata plants) of less than one year and ruderal areas with an old invasion of C. odorata (populations invaded by C. odorata plants with lignified stems, well-developed and massive shrubs) from one to three years. Floristic inventories and soil samples from 0 to 20 cm depth were carried out in quadrats of 4 m2 (2 m × 2 m). A total of 36 quadrats were placed using 9 repetitions per biotope. A morpho-pedological description of the BNP soils according to the toposequence was also carried out. The results showed that theBNP soils belong to the class of ferrallitic soils or Ferralsols. The summits are not preferential growth environments for C. odorata. The species adapts with difficulty to this type of environment. Mid-slopes are environments where we can observe the growth of C. odorata. The species manages to adapt to this type of environment. Finally, the bottom of slopes are preferential environments for the growth and proliferation of C. odorata. The species grows easily, proliferates and even becomes invasive.

Azagny National Park, is only coastal park in Côte d’Ivoire classified a zone RAMSAR. However, It is subject to strong degradation. The most common causes are peripheral agriculture, harverting of non-timber and wood forest products. All these factors lead to the increase of tracks, and therefore of ruderal areas, which facilitate the establishment, abundance and proliferation of invasive plants. These species are among the greatest threats to the integrity of protected areas and their struggle is a challenge. It is therefore necessary at first to know the ruderal flora of the park which is hitherto little known, to determine the invasive plants present in the park. The general objective of this study to improve knowledge of the flora and vegetation of the ruderal areas of Azagny national park. To achieve this objective, floristic inventory was carried in 92 plots of 50 m2 (5m x 10m) equidistant from 300m. The plant species were inventoried taking into account their abundance-dominance. The flora contains 150 species. 18 species with a particular status were inventoried. Ruderal areas of the park are home 15 invasive plants, including ten proven invasive plants, four potential ivasive plants and one species to monitor. Phytosociological study identified three plant groups including one of which were colonized by invasive plants. It is necessary to put in place a strategy and an action plan for these invasive plants in order to avoid the possible evolution in this forest heritage.