A comparison of soil respiration, carbon balance and root carbon use efficiency in two managed Moso bamboo forests in subtropical China

Abstract

Tang X., Fan S., Qi L., Guan F., Su W., Du M., 2016. A comparison of soil respiration, carbon balance and root carbon use efficiency in two managed Moso bamboo forests in subtropical China. Ann. For. Res. 59(1): 3-20.Abstract. Moso bamboo forest (Phyllostachys heterocycla [Carr.] Mitford cv. Pubescens) is an important forest type in subtropical China and comprises an important pool in the global carbon cycle. Understanding the effects of the stand management, such as understory removal, on soil respiration (RS) will help to provide a more accurate estimation of carbon cycling and predict future climate change. The study aimed to compare RS and net ecosystem production (NEP) in two Moso bamboo forests managed by the application of herbicide (AH) and conventional hand-weeded (HW) treatment, and further examine their root carbon use efficiency (RCUE). Trenching and litter removal were used to partition the source components of RS and one-year field measurement was conducted. Maximum-minimum approach was used to estimate fine root production. NEP was determined by the balance between NPP of vegetation and heterotrophic respiration (RH) of soil. RCUE was calculated using an indirect method. In both stands, soil temperature and soil moisture at 5 cm depth were the main driving forces to the seasonality of RS. Annual RS was 31.6 t CO 2 ha -1 for the stand AH and 33.9 t CO 2 ha -1 for the stand HW, while net ecosystem production (NEP) were 21.9 and 21.1 t CO 2 ha -1 , respectively, indicating that the both Moso bamboo stands acted as carbon sinks in the scenarios of current climate change. The RCUE was 30.6% for the stand AH, which was significantly lower than that for the stand HW (58.8%). This result indicates that different stand management practices can alter RCUE and the assumed constant universal carbon use efficiency (CUE) of 50% is not appropriate in Moso bamboo forests. This study highlight the importance of partition the source components of RS and accurate estimation of RCUE in modelling carbon cycling in Moso bamboo forests.

Soil respiration of a Moso bamboo forest significantly affected by gross ecosystem productivity and leaf area index in an extreme drought event

“…Additionally, plots of soil respiration against daily temperature patterns show a rather flat relationship for the summer with a strong hysteresis. Similar findings have been reported in Moso bamboo forest of subtropical China by Tang et al (2016) and Song et al (2013) . Depth of the soil temperature measurement affected the explanatory power of soil temperature.…”

Dynamics and Controls of Carbon Use Efficiency across China’s Grasslands

“…In the eastern Amazon forest, similar results were obtained [42][43]. Specifically, enhanced precipitation reduces fine root production and brings a decreasing GPP in the alpine grassland ecosystem, increased respiration of leaf and root, and decreased NPP [38][39]. However, the correlation was not obvious in dry, cold areas and warm and humid areas [10,24,44].…”

“…4) shows that climate factors play a remarkable role in the alpine grassland (alpine steppe and alpine meadow) of the border region between Tibet and Qinghai (Figs 4d-f). The findings indicated that precipitation, temperature, and aridity index promotes CUE of alpine grasslands [3], and the responses of CUE to these factors were different in the different grassland ecosystem [1,3,13,38].…”

“…Due to precipitation impressing the response of respiration and photosynthesis to temperature [38,40] and affecting the dynamic of CUE, we explored heat and water conditions over the different grassland belt transects. In Fig.…”

Analysis of Soil Degradation Causes in Phyllostachys edulis Forests with Different Mulching Years

“…In each plot, the diameter at breast height (DBH, 1.3 m), height and age of all bamboos were measured and recorded. The age was expressed by "du", which reflected the phenomenon of "on-year" and "off-year" in moso bamboo forests [17,18]. In an "on-year", more than 90% of new shoots were produced, followed by a few new shoots in an "off-year", because moso bamboo forests produced new shoots at two-year intervals [19].…”