In collaboration with the Government of Gabon, experts from the University of Stirling, have headed an international study relating to the effect of climate change on the rainforests of Central Africa and the risk posed to elephant populations in the region.
Dr Emma Bush and Dr Robin Whytock, from the Faculty of Natural Sciences, together with Professors Kate Abernethy and Lee White, are lead authors of the study titled “Long-term collapse in fruit availability threatens Central African forest megafauna” published in the leading Science journal.
The study shows that a considerable reduction in fruit production by trees in Lopé National Park, Gabon, has corresponded with a reduction in the physical condition of fruit-eating elephants in the forest.
The study identified a 81% reduction in fruit production from 1986 to 2018, in addition to 11% reduction in the physical condition of fruit-dependent forest elephants from 2008.
The Reduction in the Production of Rainforest Fruits
This implies that, on average, various animals, including elephants, would have encountered a ripe fruit on one in every 10 trees in the 1980s, but had to look for over 50 trees today.
Changes have occurred in the region’s climate from the 1980s, becoming drier and warmer and scientists believe that this might be the reason behind the reduction in the production of rainforest fruits. During the course of the study, the mean temperature has increased by nearly 1 °C.
In Lopé National Park, certain tree species depend on a dip in temperature to promote flowering but warmer temperatures may indicate that this crucial cue to producing fruit is being overlooked.
The massive collapse in fruiting among more than 70 tree species studied at Lopé National Park, Gabon may be due to species missing the environmental cue to bear fruit, because of increased temperatures and less rainfall. Less fruit in the ecosystem will have huge impacts on forest dynamics such as seed dispersal, plant reproduction and food availability for wildlife such as forest elephants, chimpanzees, and gorillas.
Dr Emma Bush, Faculty of Natural Sciences, University of Stirling
The University of Stirling is an innovator in tropical ecology research and had founded the world’s leading Station d’Etudes des Gorilles et Chimpanzes (SEGC-The Gorilla and Chimpanzee Research Station) with the Centre Internationale de Recherches Médicales de Franceville (CIRMF, The International Medical Research Centre in Franceville) in Lopé National Park, central Gabon, in 1983.
This 37-year, ongoing partnership between the Government of Gabon and the University of Stirling has produced an exclusive data set that enables scientists to track how the wildlife of the Congo Basin and rainforests are responding to climate change.
Large animals like forest elephants are already under severe pressure in Central Africa due to hunting, habitat loss and habitat degradation. If important protected areas like Lopé National Park in Gabon can no longer support them because there is not enough food, then we may see further population declines, jeopardising their survival in the long-term.
Dr Robin Whytock, Faculty of Natural Sciences, University of Stirling
Dr Whytock continued, “We know that large bodied animals, like elephants, are disproportionately important for the healthy functioning of ecosystems and their loss could result in broad changes to forest systems and even reduce the amount of carbon stored there.”
Functioning tropical ecosystems are crucial for global health and for the regulation of global climate. The new study underscores how global climate change could be impacting animals and plants locally, via decreased food production in the forest. The study adds to the global body of evidence, emphasizing the ongoing biodiversity crisis and the impacts of rapid climatic change.
Long-term ecological research such as ours is unfortunately extremely rare in the tropics, and it is possible that similar processes are underway, but undetected, throughout the tropical rainforests of our planet.
Lee White, Honorary Professor, University of Stirling
Professor White is also the Minister of Water, Forest, Sea and Environment in the Government of Gabon.
“It is alarming that climate change may be resulting in forest elephants going hungry, and we need to seriously consider whether this is forcing elephants out of the forests to approach rural villages in search of food, resulting in an increase in crop raiding,” concluded White.
The study’s co-authors include experts from the Gabonese National Parks Agency (ANPN), Gabon; Ministry of Forests, Oceans, Environment, and Climate Change, Gabon; Research Institue for Tropical Ecology (IRET), Gabon; Royal Botanic Garden Edinburgh, United Kingdom; University of KwaZulu-Natal, South Africa; Osborne Memorial Labs, Yale University, United States; Environmental Change Institute, Oxford University, United Kingdom.
Uk-Africa Research Collaboration
The University of Stirling and the Government of Gabon have financially supported this study through a special UK-Africa research collaboration, uninterrupted for 40 years.
The Government of Gabon has offered support via its PID funding mechanism and through agreements with Total Gabon to help the work of the International Centre for Medical Research in Franceville (CIRMF), and the Gabonese National Parks Agency (ANPN).
The research program at Lopé National Park has received financial support from the European Union from 1992 via the ongoing ECOFAC program. Additional support has been received from sources including the Wildlife Conservation Society, the European Research Council, Panthera, and the University of Oxford’s Hertford College Mortimer-May scholarship.