Climate change and the water yield of snow tussock grasslands in the Upper Taieri Catchment

Abstract

Global climate change may potentially alter the ecology of snow tussock grasslands. This may in turn affect water flows in the Taieri River catchment as snow tussocks have been shown to provide high water yields through their ability to trap and retain precipitation. Future changes in temperature and precipitation are modelled for the Taieri catchment area using the model CLIMPACTS. This model shows a 0.5°C increase in temperature for the two fifty year periods up to the end of this century, but an almost negligible increase in precipitation. The increase in temperature may increase the growth rate and flowering regime of narrow-leaved snow tussock. However, the tussock grasslands will also come under increasing threat from invading pests and weeds. In order to maintain the water yield from this catchment active management of the tussock grasslands may be increasingly necessary in the future.