Swap invasive mathenge for grasslands to benefit livelihoods better, new study shows

May 3, 2021 Newsroom

Clearing invasive woody weeds, and paving the way for grasslands may have significant financial benefits to mitigating impacts of climate change in Baringo County, a new study shows.

Climate change, land degradation, and invasive alien species (IAS) such as Prosopis julifora populary known as mathenge are major threats to people’s livelihoods in arid and semi-arid areas with each of these negatively impacting the ecosystem especially vegetation that is a prime resource for pastoralists.

The study team of PhD students and scientists from various disciplines developed land use scenarios to assess the implications of Prosopis management and restoration of grasslands.

They studied the impacts Prosopis invasion and grassland degradation on soil organic carbon (SOC) in Baringo County where mathenge was introduced in the 1980s to provide wind breaks, timber, and fuel.

The Woody Weeds project compiled socio-economic data to determine the budget for Prosopis management and the financial benefits accrued from the charcoal business even as it assessed changes in SOC following root out of mathenge and the establishment of vast grasslands.

The data was linked to spatially-explicit land use maps derived from satellite images before generating possible restoration scenarios.

Dr René Eschen, an ecologist working for Centre for Agriculture and Bioscience International (CABI) said, “while Prosopis does provide these benefits, it has also spread rapidly across a large area, leading to a loss of native vegetation, agricultural areas and grazing land. These changes are primarily driven by Prosopis invasion, along with human activities such as deforestation, land clearing, overgrazing, and climate change.

The study shows that a one-off budget based on willingness to pay by Baringo residents would manage a considerable area of Prosopis in a year, and turning vast areas under mathenge into grasslands would provide significant financial benefits, said Dr René Eschen.

A sustained effort over a number of years might, therefore, enable sustainable management of a large swathes of land invaded by Prosopis.

Although Prosopis management is expensive, the study suggest that a large part of the costs in Baringo can be offset by immediate financial benefits from the sale of charcoal.

Dr Sandra Eckert, a remote sensing specialist from University of Bern, Switzerland, said grasslands provide non-monetary benefits, including regulating climate change, floods and soil erosion. However, the likelihood of grasses establishing depends on suitable climatic conditions and grazing management.

“With climate change and the associated higher variability of the beginning and duration of the various seasons, grass is considered a more secure crop compared to local staple crops like maize or beans; particularly perennial grass species that require less rain for completion of a cropping cycle,” added Dr Sandra Eckert.

This study shows that relatively small investment in IAS clearing and restoration of degraded grassland in Eastern Africa may result in significant benefits for the communities managing the land that will support traditional livelihoods.

Dr Charles Kilawe, an ecologist from Sokoine University of Agriculture, in Tanzania, said that the benefits from the management of Prosopis juliflora should not be used to promote introduction of the invasive species to new areas as this would trigger negative impacts on the environment and livelihoods.

“Integrating and linking IAS data may be particularly useful to develop accurate and realistic management scenarios that can be used to illustrate costs and benefits of management interventions, where they are most needed and most cost-effective, and thus help stakeholders select the most appropriate and feasible approach that suits their needs,” noted Dr Eschen.