Water and nutrient input:output budgets: effects of plant cover at seven sites in upland snow tussock grasslands of Eastern and Central Otago, New Zealand

Abstract

Abstract Input:output budgets of water and macronutrients over two years are reported for three cover types (unmodified snow tussock grassland; induced short (c. 10 cm) blue tussock grassland; bare soil) in replicated non-weighing lysimeters from seven upland sites, four on the Lammerlaw Range (487 m–976 m), Waipori Ecological District, Eastern Otago and three on the Rock and Pillar Range (1000 m – 1340 m), Rock and Pillar Ecological District, Central Otago. Values for alpine Celmisia viscosa herbfield and for a ryegrass — white clover pasture are included for the highest and lowest sites, respectively. Snow tussock grassland produced the greatest water yield at all six sites above 700 m. Here mean annual precipitation exceeded potential evapotranspiration (PE). Annual yields from snow tussock grassland ranged from 80% of the measured 1372 mm of precipitation on the southern Lammerlaw Range to 12% of 510 mm at the lowest site near the northern end of this Range. Yields from blue tussock turf, bare soil an...