IMPACTS OF Parthenium hysterophorus L. ON SELECTED SOIL CHEMICAL PROPERTIES AND ITS POTENTIAL DISTRIBUTION UNDER CLIMATE CHANGE SCENARIOS IN ETHIOPIA

Abstract

Parthenium hysterophorus has become a major environmental, social, and economic threats in Ethiopia. Therefore, identification and mapping of suitable habitats and impacts on soil chemical properties are vital to design future management strategies. A total of 36 soil samples were collected from P. hysterophorus invaded and non-invaded sites. A total of 1,352 P. hysterophorus occurrence records and 19 bioclimatic variables were collected from different sources. ANOVA was conducted to examine the impacts of P. hysterophorus invasion on soil chemical properties between invaded and non invaded sites per depths. Significant pairwise differences (p < 0.05) were observed among means of soil pH, calcium, electric conductivity, Phosphorus and magnesium. An ecological niche model was used to map the current and future (2050 and 2070) suitability habitat for P. hysterophorus. The ensemble model revealed that 72.8%, 18.5%, 6.8%, and 1.9% of the total area were unsuitable, low, moderate, and high suitable habitats under current climate conditions respectively. The high suitability area by 2050 and 2070 under RCP 2.6, RCP 4.5, and RCP 8.5 will be 8.4%, 8.5%, 9.6%, and 7.8%, 6.1%, and 16%, respectively. We found that the current predicted unsuitable area will probably vulnerable to loss of 176.9%, 188%, 125% under RCPs (2.6, 4.5, RCP8.5) by 2050 whereas 166.7%, 164.7%, 3,500% under RCPs (2.6, 4.5, and 8.5) by 2070. The ensemble model also revealed that the highly suitable habitat in 2050 will increase by 76.2%, 76.5%, 79.2%, under RCPs (2.6, 4.5, and 8.5). Similarly, the high suitable habitat for 2070 will increase by 74.4%, 67.2%, and 87.5% under RCPs (2.6, 4.5, and 8.5). Under similar scenarios, the total area of the moderately suitable area in 2050 under RCPs (2.6, 4.5, and 8.5) was predicted to increase by 68.7%, 68.7%, and 54.7%. In addition, 67.1%, 67.6%, and 88.1% were high suitable . Furthermore, the low suitable area for 2050 and 2070 under RCP 2.6, RCP4.5 and RCP8.5 will expand by 56.8%, 57.4%, 56.2%, and 57.3%, 58.4%, and 24% respectively. The mean diurnal range, precipitation of coldest quarter, and annual mean temperature were identified as the most determinant of the distribution of the species. The threats of this species on native biodiversity, soil chemical properties, and the economy will be high in the future unless management action is undertaken. Our study suggests that all relevant stakeholders should be organized to combat the expansion of the species to new areas particularly regions and protected areas as predicted as high suitable area