Invasive Alien Weed Species Distribution, Impacts on Agriculture, Challenge and Reaction in Ethiopia: A Review

Abstract

Invasive Alien Species are of a great concern in Ethiopia, posing particular problems on agricultural lands, range lands, biodiversity of the country, national parks, water ways, rivers, power dams, roadsides and urban green spaces with great economic and ecological consequences. In Ethiopia, there are about 35 invasive alien species were identified. Foremost among these are Parthenium hysterophorus L., Eichhornia crassipes (Mart.) Solms, Prosopis juliflora (Sw.) DC., Lantana camara L., Argemone ochroleuca Sweet, Xanthium strumarium L., Ageratum conyzoides L., Datura stramonium L., Nicotiana glauca Graham, Senna didymobotrya (Fresen.) Irwin & Barneby and Senna occidentalis (L.) Link. They have been identified as a threat to Agriculture land, biodiversity of the country and economic well-being of its people. Their high seed production capacity and spread, adaptation to wide climatic and soil conditions, spread by animal movement and their association with pastoralists way of life and overgrazing are challenges to their management in Ethiopia. Parthenium exert strong allelopathic effect and reduce the growth and reproductively of associated crops. Labor-intensive control of parthenium resulted in some of them developing skin allergies, itching, fever, and asthma. Eichhornia crassipes restrict proper water flow, water loss through excessive evapo-transpiration, interference with fishing, grazing and crop production activities, effect on power generation, increase siltation, flooding, and increase cost of production. Prosopis form impenetrable thicket that prohibits free movement of people and animals and its thorns damage eyes and hooves of animals. Current costs of Prosopis invasion in Ethiopia was estimated 2.2 billion Birr. More resources have to be invested to tackle the IAS problem as the estimated loss is disproportionate to the cost of investment on IAS research and development activities. This paper attempts to review the available research information on IAS, i.e, distribution and spread, impacts, control measures and suggest the future prospects on research and management.

Keywords: Alien Invasive Species, Ecological distribution, Ethiopia, Impact