Mechanisms underlying the resilience of Dipterocarp forests to large scale climatic changes
Dipterocarp forests of Southeast Asia are one of the oldest and most diverse forests on the planet. Due to their high timber value they have been reduced to only 50% of their previous range and continue to have world’s highest deforestation rates. Projected climate change is expected to exacerbate current threats to these forests.
The nature and extent of the impacts of climate change on biota is difficult to forecast as most of our data on species distribution and dynamics have been collected in recent past (<150 years). Unlike palaeoecological records, observational datasets rarely encompass climatic changes comparable to those projected for the future. Thus, long-term ecological data play a crucial role in improving our understanding of the potential response of species and ecosystems to the upcoming climate change. Virtually nothing is known about the long-term dynamics of Dipterocarp forests and their capacity to persist under changing climates. The aim of this project is to provide valuable insights on the subject by generating the first paleorecord of Dipterocarp forest dynamics, spanning the last 2,000 years.
More specifically, I aim to answer some of the long-standing questions about the ecology of Dipterocarp forests. For instance, how do large-scale changes in El Nino/ Southern Oscillation (ENSO) variability affect supra-annual mast fruiting events in these forests? To what extent major changes in drought and fire regimes influence forest composition and structure? What are the mechanisms underlying the resilience of Dipterocarp forests to large scale climatic changes? To tackle these questions, I will be taking a multi-proxy approach, examining fossil pollen, macrocharcoal, leaf wax compounds and geochemical signatures from the sedimentary sequence of Bulusan lake, Philippines. These records will allow direct measurement of the rate and magnitude of Dipterocarp forest responses to a range of environmental disturbances such as drought, fire and volcanic eruptions.
Publications
Ana Prohaska, Alistair WR Seddon, Bernd Meese, Katherine J Willis, John CH Chiang, Dirk Sachse, Abrupt change in tropical Pacific climate mean state during the Little Ice Age, Communications Earth & Environment, 4(1) 227 (2023). https://doi.org/10.1038/s43247-023-00882-7
Ana Prohaska, Alistair W. R. Seddon, Oliver Rach, Andrew Smith, Dirk Sachse, Katherine J. Willis, Long-term ecological responses of a lowland dipterocarp forest to climate changes and nutrient availability, New Phytologist (2023) https://doi.org/10.1111/nph.19169
Ana Prohaska, Alistair Seddon, Bernd Meese, Katherine Willis, John Chiang, Dirk Sachse, Abrupt shift to El Niño-like mean state conditions in the tropical Pacific during the Little Ice Age, EarthArXiv, preprint https://eartharxiv.org/repository/view/3159/
Ana Prohaska, Alistair WR Seddon, Bernd Meese, Katherine J Willis, John CH Chiang, D Sachse, Paleosediment-and model-derived data used for the reconstruction of environmental conditions during the Holocene at the Bulusan Lake, Philippines, V. 1.1. GFZ Data Services. https://doi.org/10.5880/GFZ.4.6.2020.007
