Impact of Parthenium hysterophorus L. (Asteraceae) on Herbaceous Plant Biodiversity of Awash National Park (ANP), Ethiopia

This study was conducted in Awash National Park (ANP), East Shewa Zone of Oromia National Regional Sate, Ethiopia, aimed at determining the impact of parthenium weed (Parthenium hysterophorus L.) on herbaceous diversity. A transect belt of 13.5 km * 0.10 km of parthenium weed infested land was identified for the determination of the impact. Four quadrats were purposively laid every 250 m interval two for infested and two for non-infested each from both sides of the road and a total of 216 quadrats of 2 m x 2 m (4 m2) were considered. A total of 91 species were identified from which five of them were out of the quadrats. All species were categorized into 21 families, from which Poaceae and Fabaceae shared about 40%. The species in the non-infested quadrats were found to be more diverse and even when compared to those of the infested quadrats. Infested quadrats were found to be more abundant and dominant. Tetrapogon tenellus was found the dominant specie in the non-infested quadrats while Parthenium hysterophorus was found dominant in the infested followed by T. tenellus. There was no statistically significant difference between the total stand crop biomass of the infested and non-infested. Parthenium weed have been found creating great challenge on herbaceous plant diversity of ANP.