Seed regeneration of invasive species: germination ecophysiology and woody vegetation encroachment processes in Borana, southern Ethiopia

Description

The spread of invasive woody plants is a common worldwide challenge. Similar to other African savannas, vast areas of Borana rangelands of southern Ethiopia are encroached by native invasive woody plants. The expansion in bush encroachment poses a great threat to the Borana rangelands with consequences on the environment and livelihoods of the pastoral communities. Bush encroachment leads to dense thicket bushes which negatively affect forage productivity, carrying capacity and ultimately the livelihoods and food security of local communities. On the other hand, trees assist in carbon sequestration and eventually reduce global warming. Several native species of Acacia are reported to be invasive species in Borana rangelands (Coppock, 1994). There is little information about regeneration capacity, germination ecophysiology, and process of woody vegetation in response to pastoral land use system, soil, rainfall, grazing and fire regime. Yet, this information is vital for the management and control strategies of invasive woody species. This PhD study will focus on examine the mechanisms and factors determine the invisibility of major invasive woody plants. In this regard, sets of experiments will be conducted in Borana rangeland of south Ethiopia. A combination of methods that consists of a greenhouse experiment, nursery, manipulative field experiments (germination, seedling survival and recruitment) and Geographical Information System (GIS) will be used. In line with this, various data on ecophysiological traits and morphological responses of species will be gathered. The species’ ecophysiological responses to environmental conditions, together with additional aspects of their seeds germination and regeneration ecology that will be identified in this study could provide the basis for planning environmentally sound control strategies in suppressing invasive species. This will help to restore rangelands’ health and enhance forage productivity to support sustainable livestock production in the region. The output further helps in predicting the potential occurrence of these and other species with similar characteristics. The study will also enable to understand the regeneration ecology and recognize ecophysiological characteristics that would make invasive species to spread in dryland.

Involved persons

• Assoc. Prof. Dr. Tesfaye Abebe
• PhD Scholar Teshome Abate Beza

Involved institutions

• School of Plant and Horticulture Science
• College of Agricultural Sciences
• Food Security Center (791)

Sponsors

Supported by the DAAD program Bilateral SDG Graduate Schools, funded by the Federal Ministry for Economic Cooperation and Development (BMZ)