Widespread rangeland degradation in Namibia has changed the landscape dramatically. Decades of farming has altered the soil quality and allowed for invasive thornbushes to take root and flourish. As a result, farmers often try to clear these bushes so their livestock can graze on the land, but doing so continues to alter the soil quality. Removing the bushes exposes the land for open-savanna-adapted species, including cheetah and its prey. However, it also prohibits the nutrients contained in those plant materials from entering back into the soil, perpetuating a vicious cycle that continues to promote vigorous thornbush growth.
Researchers at the Namibia University of Science and Technology (NUST), Cheetah Conservation Fund (CCF), and Columbia University recently set out to evaluate how various debushing practices on CCF farms impacted soil quality. They sampled soil from areas that had been uncleared, partially cleared, or totally cleared for varying amounts of time and then measured how well plants grew in those soil samples. The soil samples revealed that soil fertility decreases as more and more thornbush is removed. It was also noted that soil quality did not improve when bushes were allowed to grow for as long as 13 years, hinting that soil restoration of nutrients, where grasses can thrive again, takes perhaps decades.
With this useful information, this team suggested that thoughtful linear debushing techniques could be employed that would allow thornbush growth areas to gradually improve soil fertility while providing linear clear land corridors for grazing livestock and wild savanna species.
Studies like these show that there are promising ways to improve the landscape for both farmers, wildlife and cheetahs simultaneously. Fertile land for farmers that are economically successful, but that also encourage healthy ecosystems with open wildlife corridors, is critical to cheetah survival. By studying soil imbalances, we are reminded that the cheetah and its future are connected to an intricate and complex ecosystem that cannot be overlooked in cheetah conservation.