Responses of SOM decomposition to changing temperature in Zoige alpine wetland, China

Abstract

Alpine wetlands are considered to be very sensitive to future climate warming. Understanding changes in decomposition rates (Rs) of soil organic matter (SOM) and temperature sensitivity (Q 10 ) in alpine wetlands, under the scenarios of a warming climate and decreasing soil moisture, is important for predicting their carbon (C) budget. Here, we established three sampling transects from wetland edge to meadow in the Zoige alpine wetlands in China, which represented the gradients of decreasing soil moisture. We conducted an incubation experiment (5-25°C) to explore changes in Q 10 with the degradation process from alpine wetland to alpine meadow. The results showed that temperature significantly influenced Rs in all locations. Rs first increased from site I to site IV and then decreased from site IV to site V. However, Q 10 and activation energy (E a ) showed no apparent trends with soil coming from sites along a moisture gradient. Overall, the Q 10 values in the wetland (sites 1.50) were significantly lower than that of the meadow (1.83); similar trends were observed for E a . In addition, E a exhibited a negative logarithmic relationship with C quality indices in all locations, which suggested that the C quality-temperature hypothesis is applicable to both alpine wetlands and meadows. These findings provide a theoretical foundation for predicting the potential influences of warming climate on soil C turnover and storage in alpine wetlands.

Paleoenvironment change and its impact on carbon and nitrogen accumulation in the Zoige wetland, northeastern Qinghai‐Tibetan Plateau over the past 14,000 years

“…Gir on et al, 2015; Ma et al, 2016;Sierra et al, 2015;Wang et al, 2015;Xue et al, 2015]. The environmental conditions revealed by Trans(%) in the HY2014 profile were very similar to results from the previous studies [Wang et al, 2010;Yu et al, 2006] (supporting information Figure S5).…”

“…Peat humification is usually used to estimate the degree of decomposition of plant residues. Low temperature and moisture conditions will limit the decomposition of OM, and the decomposition rate will be higher under warm and humid conditions when the biomass is also higher [ Gabriel and Kellman , ; Gutiérrez‐Girón et al, ; Ma et al ., ; Sierra et al ., ; Wang et al ., ; Xue et al ., ]. The environmental conditions revealed by Trans(%) in the HY2014 profile were very similar to results from the previous studies [ Wang et al ., ; Yu et al ., ] (supporting information Figure S5).…”

Responses of Alpine Wetlands to Climate Changes on the Qinghai-Tibetan Plateau Based on Remote Sensing

“…Yang and Cui (2005) explored the response relationship between surface water and climate in Bayanbulak alpine wetland from the 1950s to early 21st century. However, regarding to alpine wetland located to climate changes, the current research target is mainly focused on the Zoige wetland (Gao et al, 2011;Bai et al, 2013;Cui et al, 2015;Xue et al, 2015), while other alpine wetlands in the QTP are rarely involved. However, whether the response of alpine wetlands across the QTP to climate changes had the same or similar response to climate change still remains unknown.…”

Soil Organic Carbon Dynamics and Influencing Factors in the Zoige Alpine Wetland from the 1980s to 2020 Based on a Random Forest Model

“…Previous studies on carbon cycling in the Zoige wetland have mainly focused on greenhouse gas emissions and carbon loss during different degradation stages [2,[28][29][30], which deepens our understanding of carbon cycling in the Zoige wetland, but there is currently a lack of knowledge on the spatiotemporal variation and influencing factors of organic carbon in the Zoige wetland. Some scholars have used a space-for-time substitution approach to fit independent variables with carbon stocks to obtain the driving factors of organic carbon change [6,31], but most of them have only used annual temperature, precipitation, and soil moisture as their independent variables, neglecting other climate, biological, and soil factors. Additionally, this method cannot reflect the dynamics of organic carbon in the entire wetland.…”