Response of Soil Respiration to Soil Temperature and Moisture in a 50-Year-Old Oriental Arborvitae Plantation in China

Abstract

China possesses large areas of plantation forests which take up great quantities of carbon. However, studies on soil respiration in these plantation forests are rather scarce and their soil carbon flux remains an uncertainty. In this study, we used an automatic chamber system to measure soil surface flux of a 50-year-old mature plantation of Platycladus orientalis at Jiufeng Mountain, Beijing, China. Mean daily soil respiration rates (Rs) ranged from 0.09 to 4.87 µmol CO2 m−2s−1, with the highest values observed in August and the lowest in the winter months. A logistic model gave the best fit to the relationship between hourly Rs and soil temperature (Ts), explaining 82% of the variation in Rs over the annual cycle. The annual total of soil respiration estimated from the logistic model was 645±5 g C m−2 year−1. The performance of the logistic model was poorest during periods of high soil temperature or low soil volumetric water content (VWC), which limits the model's ability to predict the seasonal dynamics of Rs. The logistic model will potentially overestimate Rs at high Ts and low VWC. Seasonally, Rs increased significantly and linearly with increasing VWC in May and July, in which VWC was low. In the months from August to November, inclusive, in which VWC was not limiting, Rs showed a positively exponential relationship with Ts. The seasonal sensitivity of soil respiration to Ts (Q10) ranged from 0.76 in May to 4.38 in October. It was suggested that soil temperature was the main determinant of soil respiration when soil water was not limiting.

The effects of thinning on carbon stocks and fluxes in a Chinese arborvitae plantation

“…Average soil respiration varied between 1.12 and 7.90 μ mol CO 2 m -2 s -1 during the growing period, typical of Chinese arborvitae (Yu et al 2011). The apparent conservation of soil respiration across treatments is consistent with the findings of Vesala et al (2005) and Campbell et al (2009), who found that soil respiration was unaffected by thinning treatments in ponderosa pine (Pinus ponderosa P. Laws.…”

“…All these will affect soil microbial respiration and root respiration. Soil temperature and moisture may explain temporal variation in soil respiration (Yu et al 2011). Increased soil temperature (Ts) and soil moisture (Ms) may also enhance root growth of remaining trees, given that there is less below-ground competition for water and nutrients (Santantonio andSantantonio 1987, Van Lear et al 2000) and photosynthetic rates (Gravatt et al 1997, Peterson et al 1997.…”

Response of soil respiration to temperature and soil moisture: Effects of different vegetation types on a small scale in the eastern Loess Plateau of China

“…These data are in the same range as those from other reported studies (Savage & Davidson 2001;Rey et al 2002;Kang et al 2003), except for one study in China (Yu et al 2011). For example, in the temperate broad-leaved Korean Pine forest in the Chang Bai Mountain area of China, the released CO 2 efflux was 1017 g C m 22 (Wu et al 2006).…”

Vertical and seasonal variations in soil CO2 production in a 55-year-old oriental arborvitae (Platycladus orientalis) plantation in China

“…They are the major abiotic factors controlling soil CO 2 concentrations, which often have a temperature-driven seasonal pattern, and summer rains can lead to increases in CO 2 concentrations (Yu et al 2011, Chang et al 2016. After a rainfall, CO 2 concentrations rose markedly and θ was highest in the deepest horizon.…”

“…The role of soil in China's terrestrial carbon balance is a large source of this uncertainty (Piao et al 2009). Soil respiration has been determined in most districts of China (Tian et al 2010, Yu et al 2011, Pang et al 2012, but due to the limitations of measuring techniques, vertical and seasonal variations of soil CO 2 in planted forests is limited.…”