Roadside invasive Hyptis suaveolens ((L.) Poit, 1806) colonies green energy potential in the soudano-guinean regions of Benin

Résumé

Invasive species pose significant challenges to biodiversity and the community. Mitigation strategies include eradication attempts and biomass harvesting without integrating the invader into the resource chain. In the Republic of Benin, Hyptis suaveolens is a nationwide invasive plant species that develops in pure colonies in many ecological areas, including roadsides. This research evaluated the biomass and sequestered carbon potentials of roadside colonies in the soudano-guinean regions of Benin. Main managed roads, main rural roads, and rural pathways, located in the department of Zou, were assessed using 1m diameter circular plots around the dominant stem of the colonies during the dry season (February & March) of 2024. The 5cm above-ground humid weight of the stems on the plots and their humidity were measured and converted into dry matter (biomass) per road category. The corresponding sequestered Carbon was determined by converting the biomass to sequestered Carbon based on the photosynthesis chemical reaction. These roadside Hyptis suaveolens colonies produce 7843.11±320.86 kg/ha dry matter per year, corresponding to

11505.85±469.44kg/ha of sequestered carbon from an average 18.49±7.99 stems/m². The eastern parts had the lowest biomass productivity,

while the south had the highest biomass potential. The roads had similar stem density. Rural pathways had robust stems and bore the highest biomass, as well  as sequestered carbon. The  invasive  plant  produces high biomass  in the soudano-guinean  regions of Benin. However,  its valorization for green energy requires deeper investigation to prevent worsening its spread and impacts on vulnerable ecosystems.