Notice of Retraction: Diurnal Dynamic Characteristics of Soil Respiration and Environmental Controls during Winter in Urban Lawn Ecosystem, Northeast China

Abstract

Soil respiration diurnal dynamics during winter is important for accurately estimating annual carbon budgets, modeling the effects of urban vegetations on soil carbon storage. We conducted field experiments in urban lawn in Shenyang, north China, to measure soil respiration diurnal dynamics during winter. Our results indicated that, in sunny day diurnal soil respiration fluctuations showed relatively high single-peak curves and asymmetric patterns, with minimum and maximum occurring in early morning 0.3 μmol CO2 m-2 s-1 (3:00-7:00) and mid-day 1.29 μmol CO2 m-2 s-1 (10:00-15:00), respectively. No obvious diurnal trends in soil respiration rates were observed on cloudy day, during and after the rainfall events days. Daily average CO2 efflux of sunny day, cloudy day, rainy day and the day after rainfall was 0.80, 0.35, 1.48 and 0.86 μmol CO2 m-2 s-1, respectively. Soil respiration rate and soil temperatures at 10 cm depth exhibited strong exponential relationships and can be described by the equations Rs=0.14614e0.208T (R2=0.52, P<;0.001, Q10=8.13). The diurnal variation in soil respiration had significant correlation with daily soil volumetric water content at 5 cm depth and can be described by the equations Rs=a+bw (R2=0.65, P<;0.001). Soil temperature explained 52% of the changes in soil respiration, and soil volumetric water content explained 65% of the variation in soil respiration.