Inferring Legacy of Human Activities on Tropical Forest Plant Diversity with Spatial Genetics and Remote Sensing

Mature tropical forests have experienced significant rates of change over the last decades due to human activities. These changes, including substantial declines in biodiversity, are typically evaluated using the assumption that tropical forests were pristine and untouched by humans until very recently. However, a growing body of evidence suggests that long-term legacies from past human activity may also play a crucial role in determining current levels of tropical forest diversity and their ability to cope with ongoing anthropogenic and climatic changes.

The recognition of indigenous past management activities has led to a more complex understanding of human impact on contemporary ecological communities. Management practices of early humans have left a lasting mark on tropical forest ecosystems through a process called human niche construction, when humans modify their living environment, they create new conditions by physically changing factors at its current location in space and time. Legacies in plant communities have been created by early introduction of plant species from elsewhere, fire management and land clearing that sought to promote oligarchic forests dominated by plant species that were highly valued by indigenous communities. This suggests that human niche construction constitutes a link between some present-day patterns of biodiversity and anthropogenic activity in the distant past. Therefore, it is essential to understand these historical legacies in tropical forests, in order to better anticipate future biodiversity responses and develop more effective conservation and restoration strategies.

My PhD project aims to unveil patterns and effects of the legacy of human presence on plant species and traits diversity in Borneo tropical forests. We aim to estimate relative effect of past human activity on forest plant community diversity and the diversity of functional traits of archaeological sites, as well as the surrounding landscape. We predict that such effects occur along a gradient of distance to human settlement. I use a novel combination of archaeological surveys, remote sensing and field data, expecting to detect persistent effects of long-term human presence on species and functional diversity, even if dampened by natural restoration and forest resilience. Recognizing the long-term human shaping of global biodiversity is key to understanding contemporary and future ecosystems and their restoration.

This fellowship is hosted by the Zurich-Basel Plant Science Center.