Ecological Assessment and Sustainable Management of Geothermal Vegetation in The Waikato Region, New Zealand

Abstract

Geothermal vegetation - influenced by surface expressions of heat from the Earth’s interior - is naturally rare in New Zealand, and internationally. The varied nature of geothermal manifestations, due to varying combinations of temperature, chemistry, hydrology, and localised protection from frosts, produces rare and unusual habitats for plants. These include habitats for threatened and naturally rare plant species, as well as species occurring outside ‘normal’ latitudinal and altitudinal ranges. The varied nature of geothermal vegetation, one of the most threatened ecosystems in New Zealand, has important implications for management, including retention of existing areas and the maintenance and enhancement of ecological values. Inventories of geothermal vegetation were recently updated for the Waikato Regional Council, covering c.734 ha at 64 sites within 15 geothermal systems. Energy production (thermal and hydro-electricity, heating, and industrial uses), land use changes such as mining, farming, forestry, urban development, tourism, and fire has resulted in the loss of significant geothermal areas in the past, and such activities still threaten geothermal vegetation today. Invasion of pest plants, particularly introduced conifers and other woody plants, is a major threat at many sites. Monitoring, protection, and restoration where possible, are essential to halt the decline of these fragile and unique ecosystems.