Elephant impacts on savannas after death – do elephants “live” forever?
In the deep oceans far from land-locked Kruger National Park it is well understood that when a whale dies, the decomposing carcass creates a nutrient-rich environment on the ocean floor. These nutrient-enriched sites create localised hotspots that can supply sustenance to a variety of deep-sea organisms for decades. As the largest land mammal, could the death of an elephant create a persistent hotspot with increased biodiversity and ecosystem processes on land comparable to a marine whale fall?
This is the big (pun intended) question behind a US National Science Foundation-funded project involving scientists from the University of California – Santa Barbara, Marquette University, Utah State University, the South African Environmental Observation Network and SANParks. Elephants are often referred to as ecosystem engineers because they are huge role-players in changing the physical landscape by, for example, pushing over trees and digging holes in dry riverbeds. Yet, it is intriguing to consider that these engineers may have lasting effects on the savanna landscape even after death. Nutrients in the form of blood, soft tissue and bone from an adult elephant carcass essentially create a pulse of fertilisation in a generally nutrient-poor environment. The research team hypothesis that these carcass sites form nutrient and biogeochemical hotspots with altered soil chemistry, which eventually change plant communities and herbivore use of the landscape.
So, do elephants as the great engineers of African savannas leave a life-after-death legacy that lasts for many years after they have died? It is considered inappropriate for the living to speak ill of the dead, or phrased a little differently in the original latin, of the dead nothing but good is to be said. This is to be tested in the coming years with clipboard, disc pasture metre and soil auger in hand.
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This article was written by Tercia Strydom, Deron Burkepile, Izak Smit and Dave Thompson and originally published in the 2022/2023 Research Report.
