01864nas a2200145   4500008004100000245010100041210006900142300001000211490000700221520131400228100002101542700001601563700001601579856012301595       1998                        eng d00aDecomposition and nutrient dynamics of Oak (Quercus spp.) logs after five years of decomposition0 aDecomposition and nutrient dynamics of Oak Quercus spp logs afte  a3 -100 v213 aDecomposition of oak Quercus spp. logs (25 35 cm diameter, 3 m long) was compared among log substrates in Oregon, Minnesota. Kansas and North Carolina during the first five years on the ground. Decomposition of whole logs (weighted by substrate) averaged 0.069 yr-1 (±0.16 SD). but followed a 2-exponential model (k = 0.12 yr-1 year 1 and k = 0.06 yr -1 years 2 5), reflecting qualitative differences among log substrates (outer and inner bark, sapwood and heartwood). Rapid loss from bark substrates contributed to the initial rapid decay rate. Sapwood decay rate averaged 0.15 yr-1 and dominated the second log decay rate. Heartwood lost only 6% mass during the first five years, for an overall decay rate of 0.012 yr-1 that likely will represent a longer-term third exponential decay rate.

Carbon loss amounted to ca 5 kg yr-1 per 170 kg log. Nutrient concentrations generally declined during the first five years, but nitrogen, sulfur, and sodium accumulated in sapwood and heartwood during this period. Sulfur content increased in all substrates and doubled in whole logs during this 5-yr period. Complex patterns of nutrient content suggest patterns of microbial colonization and nutrient utilization. Polynomial models were developed to describe rates of carbon and nutrient flux in log substrates.1 aSchowalter, T.D.1 aZhang, Y.I.1 aSabin, T.E.  uhttp://knz.lternet.edu/content/decomposition-and-nutrient-dynamics-oak-quercus-spp-logs-after-five-years-decomposition