Spatial Distribution of Parthenium hysterophorus : Impact on Plant Species Diversity and Soil Characteristics in Gamo Zone, Southern Ethiopia

The invasions are severe and have an impact on pasture lands, farmlands, and conservation areas. However, there is little data on Parthenium hysterophorus L. ( Parthenium ) mapping using GIS in the Southern Region of Ethiopia. The objective of this study was to map the spatial distribution of Parthenium which affects the diversity of plant species and physicochemical characteristics of the soil. For the study, three districts in the Gamo Zone like Arba Minch Zuria, Kucha, and Dara Mallo were selected. Parthenium abundance and point data were collected randomly from 400 m 2 square quadrats from nine sites on 15 transects and 101 sampling quadrats. Then, abundance and presence of the items were observed and recorded. Meanwhile, plant species and soil samples (0–15 and 15–30 cm depths) collected from invaded and non‐invaded lands were collected in cultivated, grazing, and woodlands. Parthenium was found to be abundant in cultivated lands, along roadsides, and on grazing lands. However, the density of Parthenium was the lowest on forest lands. The non‐invaded cultivated areas had higher Shannon diversity index (1.82), species richness (9), and Shannon evenness (0.85) than the invaded lands. Meanwhile, the invasion of Parthenium had no effects on soil properties across sites or between invaded and non‐invaded areas. However, the invasion of Parthenium affected Ca 2+ across sites that ranged between 1.2 mg/kg at the Dana site of Kucha district to 1.5 mg/kg at the Shara site of Arba Minch Zuria district. This indicates that further research will be needed to confirm the effects of Parthenium on plant species diversity and soil properties across sites and in the invaded and non‐invaded lands.