Journal Article
Climate change, land degradation and invasive alien species (IAS) threaten grassland
ecosystems worldwide. IAS clearing and grassland restoration would help to reduce
the negative effects of IAS, restore the original vegetation cover and sustain liveli-
hoods while contributing to climate change mitigation, but uncertain financial ben-
efits to local stakeholders hamper such efforts. This study assessed where and when
net financial benefit could be realized from Prosopis juliflora management and subse-
quent grassland restoration by combining ecological, social and financial information.
2. Impacts of Prosopis invasion and grassland degradation on soil organic carbon (SOC)
Handling Editor: Rafael Zenni
in nine sublocations in Baringo County, Kenya, were evaluated. Then the financial
impacts of Prosopis removal and grassland restoration in the area were calculated
and spatially explicit management scenarios for each sublocation modelled, combin-
ing geographical information derived from satellite images taken in different years of
the invasion with SOC data and socio-economic data collected in the sublocations.
3. The expanding Prosopis distribution and density since 1995 have increased cumu-
lated SOC storage on former bare land or degraded grasslands. On former pristine
or restored grasslands, however, Prosopis invasion has reduced total SOC storage.
4. Prosopis removal and grassland restoration are predicted to yield financial benefits
through charcoal made from removed trees, increased cattle numbers and carbon
credits. However, a trade-off between increased SOC and net financial benefit
was found. The predicted net SOC increase would contribute around one-tenth,
at most, to the net financial benefit.
5. The available budget, based on Baringo households’ average willingness to pay,
would enable removal, on average, of one-fifth of Prosopis per sublocation in a single year. A larger area can be cleared if Prosopis is sparse than if it is dense. The
analyses show that in some sublocations, households’ annual investments could
result in restoration of all former grassland areas.
6. Synthesis and applications. This study shows how integrating and linking detailed
ecological, social and financial geodata to develop accurate and realistic invasive
alien species management scenarios can illustrate costs and benefits of manage-
ment interventions in a spatial context. Such scenarios should be used more exten-
sively to support land management decisions.
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