A few weeks ago I had the luck to visit Hluhluwe-Imfolozi National Park in South Africa. This amazing landscape is tucked into the lush green hills of Kwazulu-Natal towards the south-eastern end of South Africa.
The park has a long history, being the first game park established in Africa, and before that a hunting reserve for the Zulu kings. It has also been a pioneer in thinking about how to manage wildlife and landscapes throughout the 20th century (in ways good and bad, including extensive culling of wildlife in the mid-20th century to eliminate the region of tsetse-fly. Perhaps its most significant contribution is that was the last refuge of the southern white rhinoceros or southern square-lipped rhinoceros (Ceratotherium simum simum), which because of overhunting was reduced to just around 20 individuals hanging out in this reserve in the early 20th century. Thanks to Operation Rhino, perhaps one of the biggest conservation successes in history, this population has recovered and rhinos have been airlifted to reserves and private lands across southern Africa, such that there are around 20,000 southern white rhinos alive today, all descended from this Hluhluwe-Imfolozi population. They are now under renewed pressure, however, as poachng pressure intensifies and becomes more sophisticated.
In addition to rhinos, the reserve has abundant herbivores including elephants, giraffes and water buffalo, and predators including lions, leopards, cheetahs and wild dogs. It has played an exceptional role in our understanding of the interactions between animals, vegetation, climate and landscapes. Particularly notable are the seminal work by Norman Owen-Smith on the role of megaherbivores in ecosystem ecology, and the work by William Bond and his former students on the role of both herbivores and fires as consumers and shapers of ecosystems. To me, this work has been hugely influential in shaping our recent thinking and papers on how the the whole planet may have functioned differently at the time of the megafauna. So many of these ideas can be traced back to this corner of South Africa. It is also an area where the widespread phenomenon of woody encroachment of savannas has been studied in detail, a phenomenon many think to be a response to global increases in carbon dioxide
A detailed history and review of the science of the park has just come out as a book.
Conserving Africa's Mega-Diversity in the Anthropocene: the Hluhluwe-iMfolozi Park Story
I was privileged to be able to spend a few days in this landscape on scientific ramble, in the company of William Bond, soil fauna expert Kate Parr from the University of Liverpool, and PhD students Heath Beckett and Anabelle Cardoso. We explored how herbivores, drought and fire shape the landscape, and looked at the impact of excluding herbivores or excluding fires. These experiments show that changes are not simple or obvious, that ecosystems to not just "flip" when fire or herbivores are removed, but that key events such as droughts appear to be needed as tipping points.
As a predominantly forest ecologist, I relished hanging out with a group of people with a "savanna and grassy biome" eye, looking at the dynamic interplay between trees, grasses, forbs, animals, drought and fire. It was immensely insightful and educational (even with the tick bytes I picked up on the way!)
Yadvinder Malhi is an ecosytem ecologist and Professor of Ecosystem Science at Oxford University