Ecological dynamics and stability in the Taï and Comoe national parks in Cote dIvoire

In the heart of West Africa, two distinct worlds of nature face a common threat: the rapid loss of the variety of life that keeps ecosystems running. One world is a dense, green rainforest, while the other is a vast, open savannah. Scientists study these places not just to count animals, but to understand how well these communities can withstand change and keep functioning over time. This concept, often called stability, is about whether a group of species can bounce back after a disturbance or if it simply stays the same without much change. Some ecosystems rely on having many different species that can step in for one another if things go wrong, while others depend on the predictable, steady rhythm of their populations. Understanding which strategy a specific landscape uses is crucial, because if the wrong kind of protection is applied, or if the system has already crossed a point of no return, the entire web of life could collapse.

A recent study focused on two of Côte d'Ivoire's most important protected areas, the Taï National Park and the Comoe National Park, both recognized as UNESCO World Heritage Sites. Taï is a dense rainforest, while Comoe is a savannah ecosystem. Researchers spent a decade, from 2014 to 2025, watching the animals in these parks to see how stable their communities really are. They walked through the forest and flew over the savannah to count 107 different species of vertebrates, ranging from birds and mammals to reptiles. By tracking these numbers over ten years, the team could measure how the communities reacted to the natural ups and downs of the environment. They looked at how quickly populations recovered from setbacks, how much the different species moved in and out of sync with each other, and how predictable the overall numbers remained from year to year.

The results revealed that these two parks, though both vital, operate on completely different principles of stability. The rainforest in Taï proved to be remarkably resilient. It showed a high level of diversity, hosting a wide array of species that interact in complex ways. When disturbances occurred, the forest community bounced back quickly, largely because the different species were not all moving in the same direction at the same time. When one group struggled, another often thrived, creating a safety net that kept the whole system stable. This "portfolio effect" meant that the rainforest could absorb shocks and maintain its function. In contrast, the savannah in Comoe told a different story. Its animal communities were far less diverse and showed much weaker signs of this compensatory safety net. Instead, the savannah relied on a different kind of stability: predictability. The populations there changed very little from year to year, maintaining a steady, unchanging rhythm.

However, this steady rhythm in the savannah came with a hidden risk. The study found that the Comoe National Park lacked the ability to recover from significant changes, a quality known as resilience. While the numbers stayed consistent, the system appeared to have lost its capacity to bounce back if pushed too hard. The researchers detected signs that the savannah might have already crossed a threshold into a state of functional degradation, where the ecosystem is stable only because it is stuck, not because it is healthy. The rainforest, by comparison, showed a dynamic strength, able to shift and adapt while maintaining its core functions.

Ultimately, the study suggests that protecting these two parks requires different strategies. The rainforest needs to be managed in a way that preserves its complex web of interactions and its ability to recover from shocks. The savannah, on the other hand, faces a more urgent challenge. Because it has lost its resilience, it cannot rely on its own ability to recover from future disturbances. The findings argue for immediate restoration efforts tailored specifically to the savannah's needs, aiming to rebuild the mechanisms that allow ecosystems to recover. Without these targeted interventions, the Comoe National Park risks losing its ability to function as a living system, even if its current numbers appear steady. The two parks stand as a reminder that nature's stability is not a single trait, but a collection of different strategies, each vulnerable in its own way.