%0 Journal Article %J Journal of Vegetation Science %D 2002 %T Influence of climate variability on plant production and N-mineralization in Central US grasslands %A Barrett, J.E. %A McCulley, R.L. %A Lane, D.R. %A Burke, I.C. %A Lauenroth, W.K. %K Annual variation %K ANPP %K Central Grasslands region %K Environmental gradient %K IGBP Transect %K Mineralization %K Nitrogen flux %K Seasonal variation %X We assessed the influence of annual and seasonal climate variability over soil organic matter (SOM), above-ground net primary production (ANPP) and in situ net nitrogen (N) mineralization in a regional field study across the International Geosphere Biosphere Programme (IGBP) North American mid-latitude transect (Koch et al. 1995). We hypothesized that while trends in SOM are strongly correlated with mean climatic parameters, ANPP and net N-mineralization are more strongly influenced by annual and seasonal climate because they are dynamic processes sensitive to short-term variation in temperature and water availability. Seasonal and monthly deviations from long-term climatic means, particularly precipitation, were greatest at the semi-arid end of the transect. ANPP is sensitive to this climatic variability, but is also strongly correlated with mean annual climate parameters. In situ net N-mineralization and nitrification were weakly influenced by soil water content and temperature during the incubation and were less sensitive to seasonal climatic variables than ANPP, probably because microbial transformations of N in the soil are mediated over even finer temporal scales. We found no relationship between ANPP and in situ net N-mineralization. These results suggests that methods used to estimate in situ net N-mineralization are inadequate to represent N-availability across gradients where microbial biomass, N-immobilization or competition among plants and microbes vary. %B Journal of Vegetation Science %V 13 %P 383 -394 %G eng %M KNZ00841 %R 10.1111/j.1654-1103.2002.tb02062.x