Large tree mortality census KNP (2006-2018)

Fire and elephant herbivory are major drivers of large tree mortality in savanna ecosystems. While the spatial variation of these agents is well-studied, less attention has been paid to how disturbance history influences mortality risk for trees over time. In a long-term cohort study, we examined how the sequence of fire- and elephant-induced damage influences mortality of trees, and determined whether risk of mortality is compounded with time. Data on over 2500 large trees were collected from 22 transects in Kruger National Park, South Africa, in 2006, and trees were re-sampled in 2008, 2011, 2015, and 2018. Over the twelve year period, we recorded a cumulative death toll of 47.6% with an estimated annual mortality rate of 3-5% between 2006 and 2015, and a sharp increase to 8.8% in 2018. The main attributed agent of tree mortality was elephant damage, occurring either once or across multiple census periods. A classification tree (CT) analysis partitioned over different census periods s...