Position: Associate Professor (Earth sciences), Field: Carbon dioxide energy and water vapour fluxes from natural and managed ecosystems; hydrology, carbon exchanges and ecology of New Zealand wetlands, Organisation: University of Waikato.
Physical geography had always been a field that Dave Campbell was very interested in since his time in school. Dave studied geography at Otago University, and found the fields of climatology and hydrology particularly interesting. In particular, he was intrigued by what happens at the scale of plants and people (or microscale), by looking at the interface between vegetation and the atmosphere.
His first research topic, in 1983, was to measure evaporation from an irrigated lawn in the arid Central Otago summer. After completing this work for his honours degree, Dave had the opportunity to undertake his PhD in association with the University of Otago and the Forest Research Institute (now known as SCION). The topic for this research was the hydrology of snow tussock grasslands in eastern central Otago, which, at that time, were undergoing large-scale conversion to exotic (non-native) forest. While research had been conducted on the role of forests in reducing stream flows, there was not much work done on indigenous (native) tussock lands. At that time, there was also a heated debate about the role of tussock in ‘harvesting’ water from fog, and some of Dave’s work provided evidence that the low transpiration rate from tussock was more important for sustaining stream flows than fog interception.
Dave particularly enjoyed the opportunity this project gave him to work with some of the best scientists in this field. Part of the work they did was designing and constructing a huge instrument called a lysimeter – a device that measured how much water plants lose through evaporation by continuously measuring mass. The lysimeter that Dave and his colleagues used in this study was 3 metres in diameter and weighed 9 tonnes, with a giant weighing balance that was set in the ground beneath the tussock grassland. From this lysimeter, Dave retrieved hourly readings for 18 months, which, in the 1980s, was a considerable achievement given the lack of advanced computer hardware and software tools.
Dave then accepted a lecturing position at the University of Waikato where he has researched hydrology, CO2 and water vapour fluxes in peat bogs in the Waikato, as well as from agricultural land. Specifically, he is looking at how water and CO2 move between the land’s surface, subsurface and the atmosphere, with the plants being the living interface.
This article is based on information current in 2009.