| dc.description.abstract | This study presents the first high-resolution reconstruction of Late Holocene fire
regimes and vegetation dynamics on Bonaire, a semi-arid island in the southern
Caribbean. Using sediment cores from two hypersaline lakes (Saliña Slagbaai and
Saliña Bartol), charcoal analyses (macro-, meso- and microcharcoal) were
combined with pollen and geochemical proxies (LOI, CaCO₃, CaSO₄) to assess the
interaction between climate variability, human activity, and the occurrence of fires
over the past 2000 years. Charcoal morphology was used to infer fuel types.
ImageJ software enabled standardized particle analysis. Both records show
similar patterns in fire dynamics, indicating a strong spatial synchronicity.
Three distinct fire phases were identified: 1) A pre-ceramic natural period (~CE 0–
867) with low fire activity (1 peak per ≥600 years) and open herbaceous
landscapes (savannah-like). Fire regimes during this phase were likely driven by
biomass availability, with limited to no human impact. 2) A phase of Indigenous
land use (~CE 867–1520), indicated by Zea mays pollen, coincides with an
increased fire frequency (1 peak per ~33 years). This period also corresponds to
wetter environmental conditions, driven by a northern mean position of the
Intertropical Convergence Zone (ITCZ) during the Medieval Warm Period.
Increased precipitation led to greater biomass fuel availability, enabling both
natural and human-caused fires. 3) A Colonial and modern phase (~CE 1520–
present) characterized by fire suppression (no peaks), vegetation closure and the
emergence of drought-tolerant species. Fire activity decreased before the arrival
of Europeans. This decrease is linked to increased aridity associated with a
southward shift of the mean position of the ITCZ during the Little Ice Age.
Charcoal influx was mainly influenced by the availability of biomass fuel and
anthropogenic land use, rather than increasing aridity. Despite changes in fire
dynamics over time, charcoal morphology remained relatively stable (slightly
dominated by woody charcoal particles).
While charcoal is not a standalone climate indicator, combining it with pollen and
geochemical data can provide valuable insights into past interactions between
humans and the environment. This research improves the understanding of
ecological transitions on Bonaire and informs future land management strategies
for Caribbean dry ecosystems. | |
