Storage and controlling factors of soil organic carbon in alpine wetlands and meadow across the Tibetan Plateau

Abstract

Alpine wetlands and meadows across the Three Rivers Source Region (TRSR) store high soil organic carbon (SOC). However, information on factors affecting SOC storage is scanty. Herein, we investigated SOC storage and explored factors affecting SOC storage, including climate, soil properties and above‐ and belowground biomass, using 50 soil profiles across the TRSR on the Tibetan Plateau. The SOC storage was 491.9 ± 158.5 Tg C and 545.2 ± 160.8 Tg C in the TRSR alpine wetlands and meadow, respectively. The SOC stock was positively correlated with the mean annual precipitation. However, no significant correlation between SOC stock and mean annual temperature was observed, as opposed to the global trend. In addition, SOC stock was positively correlated with both the aboveground biomass (AGB) and belowground biomass (BGB). Soil pH indirectly affected SOC stock, while SOC stock positively correlated with Al and Fe oxyhydroxides. Compared with vegetation biomass and climatic factors, soil properties, including soil pH and Al and Fe oxyhydroxides (Alo and Feo), affected not only SOC stock variation but also affected the impact of vegetation and climatic factors on SOC stock. Climate factors, AGB, BGB, soil pH, Alo and Feo jointly accounted for 59% of SOC stock variation in alpine wetlands and 64% of SOC stock variation in alpine meadow. This study suggests that soil properties are the dominant factors affecting SOC variation in alpine wetlands and meadow on the Tibetan Plateau.

Spatial variation of soil organic carbon under major rubber planting regions in China

“…Unfortunately, our study did not directly measure the activity of microorganisms, but we were able to indirectly confirm the effect of microorganisms on SOC through the correlation between SOC components and soil pH. Under high soil pH conditions, active carbon is more likely to decompose, resulting in a decrease in SOC content (Nie et al, 2023; Wang et al, 2021). In addition to pH, SM in soil physicochemical properties also played a key role in regulating SOC content (Figure 4).…”

“…At the local scale, the variability of SOC could be influenced by factors such as stand age, climate conditions (precipitation and temperature), soil properties (moisture and temperature), biological activity, and soil management practices (Nath et al, 2018; Yang et al, 2021; Zhang et al, 2022). At the regional scale, the pattern of SOC varies due to various factors including climate‐related variables, forest type, topography, and forest management practices (Fernández‐Romero et al, 2014; Nie et al, 2023; Turner & Lambert, 2000; Zhang, Guan, et al, 2018; Zhang, Qiao, et al, 2018). In fact, several factors appear to affect SOC patterns at both local and regional scales.…”

Analysis of Vegetation Dynamics and Driving Mechanisms on the Qinghai-Tibet Plateau in the Context of Climate Change

“…Forest soils can store large amounts of water and can release it over a longer period to avoid direct climatic impacts on vegetation. Meanwhile, grasslands are more vulnerable to climate change and man-made activities [62,63].…”

Impacts of vegetation restoration strategies on soil nutrients and stoichiometry of the earthquake-induced landslides in Jiuzhaigou, eastern Qinghai-Tibet Plateau

“…Soil nutrients play a crucial role in plant growth and development, and are essential components of the terrestrial ecosystem. Soil organic carbon, for instance, is an indicator of soil quality, influencing the soil biochemical cycle (Duval et al, 2013;Nie et al, 2023). Soil nitrogen, phosphorus, and potassium directly impact leaf photosynthesis and are critical determinants of forest productivity (Wright et al, 2011;Santiago et al, 2012;Shen et al, 2020).…”