In life, elephants are described as ecological engineers because they physically change habitats, for example, by pushing over trees. A new study lead by a consortium of US National Science Foundation-funded researchers, collectively the Megacarcass Ecology Working group , is asking the question ‘Can these megaherbivores impact savanna ecology in death as well’?
Scientists know that the decay of an individual whale carcass transfers around 2 tons of carbon and half a ton of nitrogen to the ocean floor in a single pulse, essentially fertilizing the sea bed and creating patches of increased productivity and biodiversity that may last for decades. However, the impact of a multi-ton carcass in terrestrial systems is not known. The researchers anticipate that even a single elephant carcass represents a significant local-scale fertilization event that alters soil chemistry and soil microbe (primarily bacteria) communities, so driving a succession in the plant species growing at the site, as well as the nutritional value of those plants as a food source for herbivores.
At larger scales these megacarcass sites, which will suddenly appear and then slowly disappear from the savanna over the course of years to decades, may represent critical hotspots of species diversity and ecosystem functioning across the landscape. Phrased differently, savannas lacking in megafauna, as is currently typical outside of protected areas, lack this potentially significant source of nutrient input and driver of ecosystem dynamics and diversity.
Accordingly in 2022, this research investigation was launched in the Kruger National Park (KNP), in collaboration with scientists from South African National Parks (SANParks) and the South African Environmental Observation Network (SAEON).
Elephant carcass sites will be sampled multiple times each year over the next several years to build up a multi-year data set that will inform the ecological processes that link soil chemistry, soil microbe communities, plant communities, and invertebrate and ungulate herbivore activity.
Ajubatus recognizes the immense value of this research, and has a particular interest in that component assessing the microbial community at the megacarcass sites where the outcomes potentially link to the elephant and lion tuberculosis studies conducted in KNP which are being undertaken in conjunction with the Foundation.