Climate Variability in the Last 12,500 Years Has Shaped Vegetation Dynamics Differently Across West African Savannas and Forests

Why It Matters

The findings show that Holocene climate shifts drove biome‑specific vegetation responses, informing how modern climate change may differently reshape African savannas and forests and affect carbon storage and biodiversity.

Key Takeaways

• Sahel savanna functional diversity increased over Holocene
• Sudanian savanna functional dispersion remained stable
• Forests showed higher functional dispersion than savannas
• SST, δ13C, δ18O best predict Sahel vegetation changes

Pulse Analysis

Pollen records, when paired with modern trait databases, offer a rare window into how past climate oscillations sculpted Africa’s landscapes. By extending the analysis back to the Younger Dryas, the study captures a full spectrum of Holocene variability, from abrupt cooling events to gradual warming. This long‑term perspective is crucial for climate scientists because it validates the sensitivity of West African ecosystems to sea‑surface temperature shifts and atmospheric carbon isotopes, variables that also drive today’s climate models.

The research highlights a striking contrast between savanna and forest dynamics. While Sahelian savannas have become functionally more diverse—suggesting a broader range of leaf and wood strategies—Sudanian savannas have maintained a steady functional profile despite compositional changes. Forests, by contrast, exhibit both higher functional dispersion and greater compositional turnover, reflecting more complex structural adaptations. These patterns imply that savanna communities may rely on a narrower set of conservative traits, such as high wood density, to survive aridity, whereas forests exploit a wider trait palette to thrive under variable moisture regimes.

Understanding these historic trajectories is vital for anticipating future ecosystem responses. As global warming intensifies, the differentiated pathways uncovered—conservative savanna strategies versus flexible forest adaptations—could dictate regional carbon sequestration potential and biodiversity resilience. Policymakers and conservation planners can leverage trait‑based insights to prioritize areas where functional diversity buffers against climate stress, ensuring that West Africa’s critical carbon sinks and food‑security landscapes remain robust in a warming world.