This data set contains two ASCII files (.txt format). One file contains monthly productivity data measured on an arid dwarf-shrub steppe in northern Patagonia, Argentina from August 1980 to March 1982. The second file contains climate data recorded at a weather station set up onsite for the duration of the NPP study. Dynamics of above-ground biomass, dead matter, and litter were monitored at Pampa ... de Leman (45.43 S 69.83 W Elevation 400 m) at monthly or bi-monthly intervals in a 1.5 hectare exclosure area protected from sheep grazing. The vegetative community is dominated by the dwarf shrub Nassauvia glomerulosa, with two grasses (Poa dusenii and Hordeum comosum). Annual above-ground net primary productivity (ANPP) of 78 g/m2/yr was estimated from the sum of the increase in above-ground biomass, dead matter, and litter.