Eco-hydrological impacts of Eucalyptus in the semi humid Ethiopian Highlands: the Lake Tana Plain

Abstract

Abstract:Eucalyptus is the tree of choice for wood production by farmers in Ethiopia. Although there are many claims about its harmful effect on ecology and water availability, little actual research exists. The main objective of this study was, therefore, to study the extent of harm of Eucalyptus on the ecosystem. This study was conducted at the Koga Watershed near Lake Tana in Ethiopia. Twenty-five farmers were interviewed and a field experiment with three replications was carried out to quantify the effect of Eucalyptus on various soil physical and chemical properties and maize crop measurements and to compare bulk density, soil moisture contents, maize crop counts and shading effects in fields bordered by Eucalyptus and Croton macrostachyus. Our results show that Eucalyptus decreased both soil nutrients and maize yields within 20 m of the trees. Although moisture content was not affected during the monsoon, it decreased faster within 30 m of the Eucalyptus trees than elsewhere. Soils become water repellent, too. Local farmers' perception agreed with our experimental findings and indicated that Eucalyptus trees are exhausting the once productive land. They also reported that Eucalyptus dries up springs. Despite this, the growers insist on planting Eucalyptus because of its cash income.

Balancing Ecosystem Services and Disservices: Smallholder Farmers’ Use and Management of Forest and Trees in an Agricultural Landscape in Southwestern Ethiopia

“…Compared with naturally grown trees, farmers are not required to get permission from the kebele administration when they want to cut Eucalyptus. This is because in recent years the Ethiopian government has strongly discouraged the expansion of Eucalyptus trees because of the alleged negative ecological consequences (Chanie et al 2013). Because farmers find it an important tree that grows fast and provides valuable wood products, both for home consumption and the market, the Eucalyptus is now one of the most frequently planted trees in many parts of Ethiopia (Wirtu 1998, Jenbere 2009, Ango 2010.…”

The use of Eucalyptus in agroforestry systems of southern Rwanda : to integrate of segregate

“…Some authors report tree effects on crops in fields adjacent to trees to extend to a distance equal to/or several times higher than the tree heights from the tree-crop interface (Pinto et al, 2005;Chanie et al, 2013). In this study, the effect of woodlots on maize yield was limited to a distance about half the average woodlot tree height.…”

“…Many reports on crop yields as affected by trees when these are grown next to each other are usually presented as percentages or yields ha -1 relating values nearest to trees and those in open areas, far away from the trees (Sudmeyer and Hall, 2015;Tadele and Teketay, 2014;Chanie et al, 2013). This is very informative since it does not show actual proportional sizes of crops fields affected and those not affected, and the percentages are usually high, giving a wrong impressions to the readers of the magnitude of tree effects.…”

Perspectives locales et globales pour la gestion des terres des régions montagneuses du Nord de l'Éthiopie

“…Globalement, les villageois participent de manière convaincante à la reforestation et à d'autres activités de conservation (Kumasi et Asenso-Okyere, 2011). La diffusion de l'eucalyptus reste un goulot d'étranglement pour la biodiversité : les bénéfices de la plantation de ces arbres se retrouvent essentiellement au niveau des agriculteurs individuels, alors que les effets environnementaux néfastes de cet arbre très consommateur d'eau sont supportés par les communautés (Selamyihun Kidanu et al, 2005 ;Zenebe Mekonnen et al, 2007 ;Tilashwork Chanie et al, 2013).…”