Title | Influence of climate variability on plant production and N-mineralization in Central US grasslands |
Publication Type | Journal Article |
Year of Publication | 2002 |
Authors | Barrett, JE, McCulley, RL, Lane, DR, Burke, IC, Lauenroth, WK |
Journal | Journal of Vegetation Science |
Volume | 13 |
Pagination | 383 -394 |
Accession Number | KNZ00841 |
Keywords | Annual variation, ANPP, Central Grasslands region, Environmental gradient, IGBP Transect, Mineralization, Nitrogen flux, Seasonal variation |
Abstract | 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. |
DOI | 10.1111/j.1654-1103.2002.tb02062.x |