02376nas a2200265   4500008004100000245010300041210006900144300001300213490000700226520149600233653002101729653000901750653003001759653002701789653001801816653001901834653001801853653002301871100001801894700001901912700001501931700001601946700002001962856012801982       2002                        eng d00aInfluence of climate variability on plant production and N-mineralization in Central US grasslands0 aInfluence of climate variability on plant production and Nminera  a383 -3940 v133 aWe 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.10aAnnual variation10aANPP10aCentral Grasslands region10aEnvironmental gradient10aIGBP Transect10aMineralization10aNitrogen flux10aSeasonal variation1 aBarrett, J.E.1 aMcCulley, R.L.1 aLane, D.R.1 aBurke, I.C.1 aLauenroth, W.K.  uhttp://lter.konza.ksu.edu/content/influence-climate-variability-plant-production-and-n-mineralization-central-us-grasslands