Professor, Institute for Biodiversity and Ecosystem Dynamics (IBED), Research group 'Palynology and Paleo-/Actuo-ecology, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands.
- Vegetation development and cyclic and abrupt climatic change in the tropics: (high-) Andean and tropical lowland ecosystems (savannah, dry tropical forest, rain forest) during the last glacial-interglacial period.
- Spatial patterns and dynamics (at different scales) of plant and ecosystem diversity in rain forests of NW Amazonia (Colombia, Peru, Ecuador), savannah (Colombia, Venezuela, Brazil), montane forests and 'paramo' (Colombia, Ecuador, Costa Rica).
- Paleo-evidence for solar forcing of climate change: abrupt climate change as recorded in peat deposits in relation to atmospheric changes of the cosmogenic isotope 14C; solar UV variations and changing solar wind/cosmic rays as factors amplifying small variations in solar activity; sensitivity of the climate system and various ecosystems (especially bogs and lakes) to variations in solar activity; implications for our view on present and future climate change.
- High-resolution inter-hemispheric and inter-ecosystem comparisons of proxy-records that reflect key characteristics of the environment (ice, marine, terrestrial, astronomic) during periods of rapid climatic change.
- Ecosystem restoration by accelerating natural succession and modelling biodiversity recovery of montane forest fragments in Colombia and Costa Rica.
- Natural succession and strategies in space and time of Amazonian and equatorial montane ecosystems; colonisation and succession in epiphytic communities.
- Rapid climate change in relation to solar activity changes (high-resolution studies of peat and lake deposits).