Volcanic impact on terrestrial and aquatic ecosystems in the Eastern Mediterranean

Natural disturbances such as volcanic eruptions provide a unique opportunity to study past ecological dynamics. Here we illustrate the response of terrestrial and aquatic ecosystems to volcanic eruptions in connection to prevailing climate conditions. We selected five volcaniclastic depositions in the Lake Van (Turkey) sediments from different interglacial/glacial periods (Marine Isotope Stages 3 to 9e). Using high-resolution pollen data, non-pollen palynomorphs, and microscopic charcoal particles we attempted to disentangle climatic and volcanic forcing of natural environmental disturbances. Our results highlights that the thickness of subsequent volcanic deposits and the respective climatic conditions strongly influence the impact on terrestrial and aquatic ecosystems. The most common response to ash deposition is a shift towards herbaceous taxa and abrupt fire activity. The affected herbaceous vegetation recovers to pre-eruption levels in 20 to 40 varve-years. The lake water experiences intensified productivity due to subsequent nutrient input and significant increase in aquatic microfossils. Our findings pave the way for disentangling climatic and volcanic forcing of natural environmental disturbances.