Abstract:
Invasive Alien species (IAS) are considered to be one of the most serious challenges worldwide to mankind, biodiversity and environment. But, studies widely agree that actions to eradicate and control the effects of invasive alien species focused largely within developed countries. However, in poor, fragile and vulnerable developing countries, invasive alien species cause similar or worse problems, for development as well as conservation of biodiversity. Addressing the problem of invasive alien species is currently urgent because the threat is growing daily, and the economic as well as environmental impacts are severe. This study aims to empirically estimate the total economic value of Prosopis juliflora (hereafter referred as ‘Prosopis’) invasion in Dire Dawa administration. Data were collected through a survey of 450 agro-pastoral households (250 from Prosopis invaded and 200 from non-invaded area). Both stated and revealed preference methods were used because impacts of Prosopis are both tangible and intangible. Applying the total economic valuation approach, the study found that the current costs of the Prosopis invasion in Dire Dawa administration are higher than the benefits. The Gini-coefficient shows that on-farm income as a whole accounted for 22.5%, while nonfarm income accounted for 73.5% of total income inequality in the Administration. The study further shows that while on-farm income inequality is decreasing, non-farm income inequality is increasing in rural Dire Dawa Administration. Applying a double bounded contingent valuation method, the study found that WTP for eradication measures is significantly influenced by bid level, income of the households, age of the household head, gender, physical injury incidence, size of land holding and attitudes towards payment. Moreover WTP for control measures is influenced by bid level, occupation, family size, livestock owned, participation in non-farm income earning activities and attitudes towards payment. Results indicate that eradication and control of Prosopis invasion offers 224.30 and 107.49 Birr per household, respectively. The importance of Prosopis is perceived negatively by the households with a mean value of almost 4 out of 5 rating scale. Results obtained from the PSM model reveal that Prosopis invasion has led to an increased education expenditure, average annual income from crop production, non-farm income, food and non-food expenditure and physical food consumption, whereas Prosopis invasion reduced income generation from the sale of milk products. Among the coping strategies used by households living in invaded areas, utilizing Prosopis either as a source of income or domestic consumption took the lion’s share (61.2%). The clear implication is that controlling Prosopis through utilization is the most preferred management option in the study area