Get reliable science

The natural abundance of deuterium (2H) within soil water, groundwater and plant sap has been useful in determining sources of water used by a range of plants species growing in deserts, savannas and riparian systems. This, combined with "heat pulse" methods for measuring amount and direction of sap flow, can estimate of the volume of water used by trees within the landscape with different water availability. Increasing extraction of groundwater by government agencies, the mining industry and pastoralists in the Pilbara has focused attention on the health and survival of riparian vegetation. However, there has been no quantitative analysis of the sources and availability of water to any species in the Pilbara.

 

Despite increasing industrial use, the role of groundwater in maintaining /supporting ecosystems is poorly understood throughout semi -arid Australia and limited to assumptions based on descriptions of plant communities. This paper summaries numerous detailed studies of the physiology of Eucalyptus and Acacia spp. at Hamersley and Marillana Stations in the Pilbara. We used a landscape approach to assess plant responses to a gradient of water availability, where depth to groundwater increased with distance from creek-lines. Species growing in creek-lines used both soil and groundwater, but the source was dependent on season. The implications of these finding are discussed in terms of possible changes in plant

communities, in response to changes in water availability resulting from a disturbance.