Fire drives major Holocene vegetation shifts between subtropical and
Mediterranean-type ecosystems: a case study from a biodiversity hotspot
in South Africa
Abstract
Fire plays a pivotal role in driving ecological shifts between
Mediterranean-type vegetation and subtropical ecosystems in South
Africa. This study investigates long-term environmental dynamics and
ecological regime changes at the Mediterranean-type vegetation
/subtropical boundary using a 6000-year palaeoecological sequence from
the Baviaanskloof – a region of South Africa characterized by high
levels of biodiversity and climate dynamism. Combining fossil pollen and
microcharcoal data from a rock hyrax (Procavia capensis) midden, we
analyse vegetation responses to environmental changes. Our findings
reveal that Mediterranean-type vegetation resilience prevailed until ca.
2800 cal yr BP when a major fire event triggered a transition to a
subtropical thicket-dominated environment. This abrupt ecological
turnover underscores the significance of fire as a major driver of
vegetation change at the Mediterranean-type vegetation /subtropical
boundary. Our study emphasizes the vulnerability of Mediterranean-type
vegetation ecosystems to global environmental change, suggesting
potential implications for similar biome boundaries worldwide. By
integrating multi-proxy palaeoecological evidence, we gain insights into
the resilience and vulnerability of these ecosystems, aiding in
understanding future responses to climate change scenarios.