Simon Lewis is a plant ecologist by training with a central focus on tropics and global environmental change.  His primary interest is in how humans are changing the Earth as a system. This is because one of the key issues facing humanity in the 21^st century will be to address how a population of at least 8 billion can lead fulfilled lives without breaching environmental thresholds that may cause serious social, economic and environmental disruption, or even more severe outcomes.

The more specific focus of his research is to gain a synthetic understanding of the recent, current, and likely future compositional and functional trajectory of the tropical forest biome. That is, to understand how and why tropical forests are composed of the tree species that form these forests, understand their important functions, such as how much carbon they store and cycle, and understand how these systems are changing due to local, regional and global environmental changes, and ultimately how they may change in the future.

Dr Lewis founded and co-ordinates the only African network of on-the-ground tropical forests monitoring plots where individual trees are tagged and monitored over time, called AfriTRON (African Tropical Rainforest Observation Network). This requires extensive fieldwork in very remote locations. AfriTRON currently spans 10 countries across tropical Africa, and with its sister network in South America (RAINFOR) consists of >500 locations and >300,000 trees being monitored. They are housed in a data repository, co-founded by Dr Lewis, at www.forestplots.net