Nitrogen transformation along an elevational and vegetative gradient.

Examination of N-transformation along elevation and vegetation gradient. These measurements are analysis of plant nitrogen availability and overall site productivity.Potential nitrogen transformation rates (net nitrification and mineralization) are measured using closed core in situ incubations of the 0-10 cm of mineral soil for 28 days. Two cores are driven into the top 10 cm of soil 25 cm apart. One core is removed and represents t=0 NH4+ and NO3- concentrations. The other core is capped with a PVC cap and left in place for 28 days. Incubations are performed at randomly selected points on each of four transects on each LTER plot, these transects are used as replicates. Three sets of nitrogen transformation measurements are conducted on the extensive plots. NH4+- and NO3- nitrogen concentrations are measured in fresh soil sieved (6mm) extracted with 2 M KCl (10 g soil:20 ml KCl) for 1 hour