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Assessment of soil organic carbon (SOC) concentration in high‐altitude shrublands is essential for understanding C dynamics in terrestrial ecosystems. Hence, we investigated the SOC concentration and its influencing factors using 198 soil profiles (0–100 cm) from 66 sites between 2011 and 2013 in the north‐eastern Tibetan Plateau shrublands. SOC concentration was different under different shrubland types, with SOC concentration significantly greater in the alpine shrublands relative to the desert shrublands, whereas SOC concentration showed limited increases with altitude. Both mean annual temperature (MAT) and mean annual precipitation (MAP) have positive relationships with SOC concentration, and their relationships are moderate. Compared with MAT, a correlation between MAP and variation in SOC concentration was larger. Meanwhile, with increasing soil depth, a correlation between variation in SOC concentration and climatic factors was smaller. Soil pH seems to be a robust factor that not only had a significant negative correlation with SOC, but also played an important role in regulating a correlation between climatic condition and variation in SOC concentration. Controls on variation of SOC concentration on the Tibetan Plateau help to understand soil C dynamics in terrestrial ecosystems. Highlights: SOC concentration was different under different shrubland types, whereas SOC concentration showed limited increases with altitude.Compared with MAT, a correlation between MAP and variation in SOC concentration was larger.Soil pH seems to be a robust factor that had a significant negative correlation with SOC concentrationSoil pH was also important for regulating a correlation between climatic condition and variation in SOC concentration. [ABSTRACT FROM AUTHOR]

Biomass partitioning has been explored across various biomes. However, the strategies of allocation in plants still remain contentious. This study investigated allocation patterns of above- and belowground biomass at the community level, using biomass survey from the Tibetan Plateau. We explored above- and belowground biomass by conducting three consecutive sampling campaigns across shrub biomes on the northeast Tibetan Plateau during 2011–2013. We then documented the above-ground biomass (AGB), below-ground biomass (BGB) and root: shoot ratio (R/S) and the relationships between R/S and environment factors using data from 201 plots surveyed from 67 sites. We further examined relationships between above-ground and below-ground biomass across various shrub types. Our results indicated that the median values of AGB, BGB, and R/S in Tibetan shrub were 1102.55, 874.91 g m-2, and 0.85, respectively. R/S showed significant trend with mean annual precipitation (MAP), while decreased with mean annual temperature (MAT). Reduced major axis analysis indicated that the slope of the log-log relationship between above- and belowground biomass revealed a significant difference from 1.0 over space, supporting the optimal hypothesis. Interestingly, the slopes of the allometric relationship between log AGB and log BGB differed significantly between alpine and desert shrub. Our findings supported the optimal theory of above- and belowground biomass partitioning in Tibetan shrub, while the isometric hypothesis for alpine shrub at the community level. [ABSTRACT FROM AUTHOR]