**5. Conclusions**

We used data from 65 sites to explore the storage, distribution, and environmental controls of litter standing crop carbon in the shrublands of the Tibetan Plateau. The litter standing crop carbon was 10.93 Tg C in the shrublands of the plateau. Most of the litter standing crop was stored in the branch standing crop, which accounted for 80% of all litter standing crop. The conversion coe fficient was 0.44 for litter standing crop to litter standing crop carbon. Spatially, the litter standing crop showed a decreasing trend with increasing longitude, and was stable with latitude. Litter standing crop carbon decreased with increasing MAP, but MAT and aboveground biomass have had positive e ffects on litter standing crop carbon in the shrublands on the Tibetan Plateau.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1999-4907/10/11/987/s1, Figure S1: Relationships among aboveground biomass, litter standing crop carbon, and climatic factors, (a) mean annual temperature (MAT), (b) mean annual precipitation (MAP); Figure S2: Relationships among longitude, (a) mean annual precipitation (MAP), (b) mean annual temperature (MAT).

**Author Contributions:** Conceptualization, G.Z. and X.N.; Methodology, G.Z., X.N.; Investigation, L.Y.; Writing—Original Draft Preparation X.N. and D.W.; Project Administration, G.Z.

**Acknowledgments:** We thank Wenzhu Song, Zebing Zhong, Hechun Liu, and Yi Ning for facilitating our field surveys on the Tibetan Plateau and laboratory assistance. This study is funded by the National Program on Basic Work Project of China (2015FY11030001-5), Qinghai Province Natural Science Fund Project (2019-ZJ-910), Qinghai Province International Exchange and Cooperation Project (2019-HZ-807) and Strategic Priority Research Program of CAS (XDA0505030304).

**Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript and in the decision to publish the results.
