Cross-boundary human impacts compromise the Serengeti-Mara ecosystem
We know that human population growth is the single most important threat to the Serengeti ecosystem. Now a team of scientists has revealed an important aspect of this, not just on the ecosystem's margins, where one would expect change, but at the very center of the ecosystem. They found human activity has affected grass cover, soils, beneficial natural fires, and the overall risk from climate change. The impact on the Masai Mara Reserve in Kenya has been especially dramatic, greatly reducing the size of the migrating wildebeest herds into this area.
Summary of the Study
"Protected areas provide major benefits for humans in the form of ecosystem services, but landscape degradation by human activity at their edges may compromise their ecological functioning. Using multiple lines of evidence from 40 years of research in the Serengeti-Mara ecosystem, we find that such edge degradation has effectively “squeezed” wildlife into the core protected area and has altered the ecosystem’s dynamics even within this 40,000-square-kilometer ecosystem. This spatial cascade reduced resilience in the core and was mediated by the movement of grazers, which reduced grass fuel and fires, weakened the capacity of soils to sequester nutrients and carbon, and decreased the responsiveness of primary production to rainfall. Similar effects in other protected ecosystems worldwide may require rethinking of natural resource management outside protected area."
Several publications have reported on this, including: