Assessment on the distribution and spread of invasive alien plant species: the case of Zone 1 and 3 of the Afar region, Ethiopia

The study was conducted with the aim of assessing the distribution and abundance of invasive alien plant species (IAPS) in two administrative Zones (1 and 3) of the Afar region. Data were collected using systematic sampling technique and regular intervals of 10 km were used during the field survey. The following weeds Calotropis procera, Cryptostegia grandiflora, Jatropha curcas, Lantana camara, Opuntia stricta, Parkinsonia aculeata, Parthenium hysterophorus, Prosopis juliflora, Senna occidentalis, and Solanum incanum were recorded in this study. Prosopis was found in 38% of the 91 sample waypoints in the altitude range of 347-1005 meters above sea level whereas C. procera was recorded in 28% of the interceptions between 347 m and 1010 meters above sea level. P. hysterophorus occurred in 15 % of the waypoints in the altitudes ranged from 603 to 1005 meters above sea level. C. grandiflora and P. aculeata were observed respectively in 3% and 6% of the interceptions while L. camara and O. stricta were recorded only at a single waypoint. Higher abundance levels were observed for P. juliflora and C. procera. The majority of the IAPS were found infesting diversified habitats such as road sides, cropland, grazing land, riversides, forest and habitation areas. Awash Fentale district had the highest IAPS richness by possessing all the recorded species. The detailed distribution maps of the identified IAPS were developed and prioritization and ranking of invasive species was made based on abundance levels. The results of this study can be used in invasive weed management or extension programs that aim to tackle major IAPS problems in the region.