Abstract
Abstract. Inclination and spatial variability in soil and litter properties influence
soil greenhouse gas (GHG) fluxes and thus ongoing climate change, but
their relationship in forest ecosystems is poorly understood. To elucidate
this, we explored the effect of inclination, distance from a stream, soil
moisture, soil temperature, and other soil and litter properties on
soil–atmosphere fluxes of carbon dioxide (CO2), methane (CH4), and
nitrous oxide (N2O) with automated static chambers in a temperate
upland forest in eastern Austria. We hypothesised that soil CO2
emissions and CH4 uptake are higher in sloped locations with lower soil
moisture content, whereas soil N2O emissions are higher in flat, wetter
locations. During the measurement period, soil CO2 emissions were
significantly higher on flat locations (p<0.05), and increased with
increasing soil temperature (p<0.001) and decreasing soil moisture
(p<0.001). The soil acted as a CH4 sink, and CH4 uptake
was not significantly related to inclination. However, CH4 uptake was
significantly higher at locations furthest away from the stream as compared
to at the stream (p<0.001) and positively related to litter weight
and soil C content (p<0.01). N2O fluxes were significantly
higher on flat locations and further away from the stream (p<0.05)
and increased with increasing soil moisture (p<0.001), soil
temperature (p<0.001), and litter depth (p<0.05). Overall,
this study underlines the importance of inclination and the resulting soil
and litter properties in predicting GHG fluxes from forest soils and
therefore their potential source-sink balance.
Funder
Österreichische Forschungsförderungsgesellschaft
Klima- und Energiefonds
Horizon 2020