Soil warming in a northern hardwood forest: trace gas fluxes and leaf litter decomposition

1998 ◽  
Vol 28 (9) ◽  
pp. 1365-1372 ◽  
Author(s):  
Patrick J McHale ◽  
Myron J Mitchell ◽  
Francis P Bowles
Keyword(s):  
Soil Temperature ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Hardwood Forest ◽  
Trace Gas ◽  
Northern Hardwood Forest ◽  
American Beech ◽  
Northern Hardwood ◽  
Gas Fluxes ◽  
Trace Gas Fluxes

The response of trace gas fluxes (CO2, CH4, and N2O) and litter decomposition to increased soil temperature was evaluated in a northern hardwood forest. Four experimental plots (10 × 10 m) had heating cables installed within the forest floor. Temperatures at 5 cm were increased 2.5, 5.0, or 7.5°C in individual heated plots during the field season in 1993 and 1994. The fourth plot was a cabled, nonheated reference. Trace gas fluxes were monitored using closed chambers. Soil moisture was monitored using tensiometers and time domain reflectometry. Changes in leaf litter decomposition were quantified using litter bags for American beech (Fagus grandifolia Ehrh.) and sugar maple (Acer saccharum Marsh.) litter. Fluxes of CO2 increased exponentially with increased soil temperatures within treatments and were higher in heated plots than in the reference plot. Temperature coefficients (Q10) and mass remaining of American beech leaf litter decreased with the level of heating, suggesting a nonlinear microbial response to elevated temperatures. Soil water content exhibited the most influence on CH4 and N2O flux in the second season. The experimental manipulations showed the importance of evaluating the influence of soil temperature coupled with effects of N and moisture availability.

scholarly journals Decadal variability of soil CO<sub>2</sub>, NO, N<sub>2</sub>O, and CH<sub>4</sub> fluxes at the Höglwald Forest, Germany

2012 ◽  
Vol 9 (5) ◽  
pp. 1741-1763 ◽  
Author(s):  
G. J. Luo ◽  
N. Brüggemann ◽  
B. Wolf ◽  
R. Gasche ◽  
R. Grote ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Trace Gases ◽  
Trace Gas ◽  
High Temporal Resolution ◽  
N2o Production ◽  
Field Station ◽  
Freeze Thaw ◽  
Gas Fluxes ◽  
Trace Gas Fluxes

Abstract. Besides agricultural soils, temperate forest soils have been identified as significant sources of or sinks for important atmospheric trace gases (N2O, NO, CH4, and CO2). Although the number of studies for this ecosystem type increased more than tenfold during the last decade, studies covering an entire year and spanning more than 1–2 years remained scarce. This study reports the results of continuous measurements of soil-atmosphere C- and N-gas exchange with high temporal resolution carried out since 1994 at the Höglwald Forest spruce site, an experimental field station in Southern Germany. Annual soil N2O, NO and CO2 emissions and CH4 uptake (1994–2010) varied in a range of 0.2–3.0 kg N2O-N ha−1yr−1, 6.4–11.4 kg NO-N ha−1yr−1, 7.0–9.2 t CO2-C ha−1yr−1, and 0.9–3.5 kg CH4-C ha−1yr−1, respectively. The observed high fluxes of N-trace gases are most likely a consequence of high rates of atmospheric nitrogen deposition (>20 kg N ha−1yr−1) of NH3 and NOx to our site. For N2O, cumulative annual emissions were ≥ 0.8 kg N2O-N ha−1yr−1 in years with freeze-thaw events (5 out 14 of years). This shows that long-term, multi-year measurements are needed to obtain reliable estimates of N2O fluxes for a given ecosystem. Cumulative values of soil respiratory CO2 fluxes tended to be highest in years with prolonged freezing periods, i.e. years with below average annual mean soil temperatures and high N2O emissions (e.g. the years 1996 and 2006). Furthermore, based on our unique database on trace gas fluxes we analyzed if soil temperature, soil moisture measurements can be used to approximate trace gas fluxes at daily, weekly, monthly, or annual scale. Our analysis shows that simple-to-measure environmental drivers such as soil temperature or soil moisture are suitable to approximate fluxes of NO and CO2 at weekly and monthly resolution reasonably well (accounting for up to 59 % of the variance). However, for CH4 we so far failed to find meaningful correlations, and also for N2O the predictive power is rather low. This is most likely due to the complexity of involved processes and counteracting effects of soil moisture and temperature, specifically with regard to N2O production and consumption by denitrification and microbial community dynamics. At monthly scale, including information on gross primary production (CO2, NO), and N deposition (N2O), increased significantly the explanatory power of the obtained empirical regressions (CO2: r2 =0.8; NO: r2 = 0.67; N2O, all data: r2 = 0.5; N2O, with exclusion of freeze-thaw periods: r2 = 0.65).

Effects of Calcium on the Rate and Extent of Litter Decomposition in a Northern Hardwood Forest

Ecosystems ◽  
2015 ◽  
Vol 19 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Gary M. Lovett ◽  
Mary A. Arthur ◽  
Katherine F. Crowley
Keyword(s):  
Litter Decomposition ◽  
Hardwood Forest ◽  
Northern Hardwood Forest ◽  
Northern Hardwood

scholarly journals Towards reliable measurements of trace gas fluxes at plant surfaces

2021 ◽  
Vol 230 (6) ◽  
pp. 2097-2099
Author(s):  
Lukas Kohl ◽  
Markku Koskinen ◽  
Mari Pihlatie
Keyword(s):  
Trace Gas ◽  
Gas Fluxes ◽  
Trace Gas Fluxes ◽  
Plant Surfaces
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