Monitoring of Geothermal Vegetation in New Zealand, and the Effects of Geothermal Energy Extraction

Abstract

In New Zealand, monitoring of natural geothermal vegetation is a requirement for all energy abstraction that occurs in geothermal fields where such vegetation occurs. Geothermal vegetation, influenced by surface expressions of heat from the Earth’s interior, is naturally rare both in New Zealand and internationally. Rare and unusual habitats for plants arise due to varying combinations of temperature, chemistry, hydrology, and localised protection from frosts. In New Zealand, all geothermal ecosystems are classified as Critically Endangered. Exploitation for energy production has the potential to be a significant threat to the viability and sustainability of geothermal vegetation and habitats. Changes to underground systems have the potential to change both the above ground character of natural areas and the distribution of species within them. Changes can include both increases and decreases in above-ground temperatures, as well as alteration of water tables, which can lead to a loss of hot springs and geysers. Most geothermal vegetation in New Zealand occurs in the central North Island, in the Taupō Volcanic Zone. Wildland Consultants has been involved in the long-term monitoring of many of the geothermal areas in New Zealand which are utilised for energy abstraction. In this paper, we examine the history, methods, and findings of current monitoring programmes, consider whether monitoring is achieving its desired purpose, and discuss what could be done differently.