Position: Associate Professor (Earth sciences), University of Waikato.
Field: Carbon dioxide1 energy and water vapour2 fluxes from natural and managed ecosystems; hydrology3, carbon4 exchanges and ecology5 of New Zealand wetlands6.
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 climatology7 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 vegetation8 and the atmosphere9.
His first research topic, in 1983, was to measure evaporation10 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 PhD11 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 indigenous12 (native13) 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 evidence14 that the low transpiration15 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 mass16. The lysimeter that Dave and his colleagues used in this study was 3 metres17 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 vapour18 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.
Useful links
Learn more about Dave Campbell’s research activities by visiting the Waikato Biogeochemistry and Ecohydrology Research (WaiBER) website.
Wondering about the machinery Dave is shown using in the images? The video Eddy Covariance: Measuring an Ecosystem's Breath offers an explanation, and this is also covered in our article Measuring gases using eddy covariance.
This article is based on information current in 2009 and 2017.
- carbon dioxide: CO2 is a colourless, odourless, incombustible gas. It is a product of cellular respiration and combustion and is an essential component in photosynthesis.
- water vapour: The gas phase of water.
- hydrology: The study of movement, distribution or quality of water throughout the Earth’s systems.
- carbon: A non-metal element (C). It is a key component of living things.
- ecology: The study of the interactions of living organisms with each other and their environment.
- wetland: An area of land that is saturated with water, often referred to as a swamp or bog. Wetlands may be seasonally or permanently water-logged with vegetation adapted for life under those soil conditions. Wetlands are known as repo in te reo Māori.
- climatology: The branch of science that studies climates (long-term weather patterns).
- vegetation: Plant life.
- atmosphere: 1. The layer of gas around the Earth. 2. (atm) A non-SI unit of pressure equivalent to 101.325 kPa.
- evaporation: The process by which a liquid is converted into a gas, without necessarily reaching the boiling point.
- PhD: Abbreviation of Doctor of Philosophy – a degree normally obtained after a concentrated period of research. This is the highest level of degree that involves supervision by academic staff at a university.
- indigenous: Originating and living or occurring naturally in an area or environment. People who are the original inhabitants of an area, or their descendants.
- native: A species that lives naturally in a country, as opposed to species that have been introduced by the activity of humans.
- evidence: Data, or information, used to prove or disprove something.
- transpiration: The process by which water exits leaves in plants and enters the atmosphere in a gas phase.
- mass: The amount of matter an object has, measured in kilograms.
- metre: The base unit of length in the International System of Units (SI).
- water vapour: The gas phase of water.