Abstract
Understanding the effects of stand age and forest type on soil respiration is crucial for predicting the potential of soil carbon sequestration. Thus far, however, there is no consensus regarding the variations in soil respiration caused by stand age and forest type. This study investigated soil respiration and its temperature sensitivity at three stand ages (5, 10, and 20 or 30 years) in two plantations of coniferous (Pinus tabulaeformis Carrière) and deciduous (Populus davidiana Dode) species using an automated chamber system in 2013 in the Beijing-Tianjin sandstorm source area. Results showed that mean soil respiration in the 5-, 10-, and 20/30-year-old plantations was 3.37, 3.17, and 2.99 μmol·m−2·s−1 for P. tabulaeformis and 2.92, 2.85, and 2.57 μmol·m−2·s−1 for P. davidiana, respectively. Soil respiration decreased with stand age for both species. There was no significant difference in soil respiration between the two plantation species at ages 5 and 10 years (p > 0.05). Temperature sensitivity of soil respiration, which ranged from 1.85–1.99 in P. tabulaeformis and 2.20–2.46 in P. davidiana plantations, was found to increase with stand age. Temperature sensitivity was also significantly higher in P. davidiana plantations and when the soil water content was below 12.8%. Temperature sensitivity incorporated a combined response of soil respiration to soil temperature, soil water content, soil organic carbon, and fine root biomass and, thus, provided an ecological metric for comparing forest carbon dynamics of these species.
Highlights
Soil respiration, ranging from 40%–90% of total ecosystem respiration, is the second largest carbon flux in terrestrial ecosystems [1]
Soil respiration was most sensitive to soil temperature when the soil water content was below 12.8% for the P. davidiana plantations (p = 0.019) (Table 3)
We showed that the Q10 value of P. tabulaeformis was lower than that of P. davidiana plantations
Summary
Soil respiration, ranging from 40%–90% of total ecosystem respiration, is the second largest carbon flux in terrestrial ecosystems [1]. Opposite opinion, considers that soil respiration decreases with stand age because of decreasing fine root biomass and metabolic activity [14,15,16]. Others consider that no linear relationship exists between soil respiration and stand age [7,17,18]. The majority of these studies emphasized the effects of stand age on soil respiration in a single forest type. Comparisons of soil respiration for different stand ages conducted at the same sites in distinct forest types, such as coniferous and deciduous species, especially under afforestation conditions, are relatively scarce [23]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call