David Wardle’s research explores the links between aboveground and belowground communities, and how these in turn drive the functioning of terrestrial ecosystems. A large proportion of this work is field based and in natural ecosystems, including in forested ecosystems around the world as well as subarctic and subalpine tundra. Major regions of current field research include northern Sweden, New Zealand, Australia, Brunei and Singapore. Current projects focus on: The community and ecosystem effects of invasive and overabundant plants and animals, including overabundant wild boar in Singapore The ecological consequences of wildfire in forests Ecosystem changes across natural gradients of elevation (and temperature), succession and retrogression Biodiversity and ecosystem functioning in island ecosystems Ecology and restoration of tropical peatland forests, with particular focus on Brunei Ecological consequences of biodiversity loss in real ecosystems