Nitrogen oxides emission from two beech forests subjected to different nitrogen loads

Kaltenburg-Lindau

2006

S. 293-310

1 Tab.

Bandaufführung

9944S

136152

We analysed nitrogen oxides (N2O, NO) and carbon dioxide (CO2) emissions from two beech forest soils close to Vienna, Austria, which were exposed to different nitrogen input from the atmosphere. The site Schottenwald(SW) received 20.2 kg N ha-1 y-1 and Klausenleopoldsdorf (KL) 12.6 kg N ha-1 y-1 through wet deposition. Nitric oxide emissions from soil were measured hourly with an automatic dynamic chamber system. Daily N2O measurements were carried out by an automatic gas sampling system. Measurements of nitrous oxide (N2O) and CO2 emissions were conducted over larger areas on a biweekly (SW) or monthly (KL) basis by manually operated chambers. We used an autoregression procedure (time-series analysis) for establishing time-lagged relationships between N-oxides emissions and different climate, soil chemistry and N-deposition data. It was found that changes in soil moisture and soil temperature significantly effected CO2 and N-oxides emissions with a time lag of up to two weeks and could explain up to 95% of the temporal variations of gas emissions.