Belowground biomass of alpine shrublands across the northeast Tibetan Plateau

Nie Xiuqing; Dong Wang; Yang Lucun; Fan Li; Zhou Guoying

doi:10.1002/ece3.6275

Belowground biomass of alpine shrublands across the northeast Tibetan Plateau

Ecol Evol. 2020 Apr 19;10(12):5315-5322. doi: 10.1002/ece3.6275. eCollection 2020 Jun.

Authors

Nie Xiuqing^{1

2

3}, Dong Wang^{1

3}, Yang Lucun^{2

4}, Fan Li⁵, Zhou Guoying^{2

4}

Affiliations

¹ Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration Research Institute of Forestry Chinese Academy of Forestry Beijing China.
² Key Laboratory of Tibetan Medicine Research Northwest Institute of Plateau Biology Chinese Academy of Science Xining China.
³ Research Institute of nature protected Area Chinese Academy of Forestry Beijing China.
⁴ Qinghai Key Laboratory of Qing-Tibet Biological Resources Xining China.
⁵ Institute of Qinghai Meteorological Science Research Xining China.

Abstract

Although belowground biomass (BGB) plays an important role in global cycling, the storage of BGB and climatic effects on it are remaining unclear. With data from 49 sites, we aimed to investigate BGB and its climatic controls in alpine shrublands in the Tibetan Plateau. Our study showed that the BGB (both grass-layer and shrub-layer biomass) storage in the alpine shrublands was 67.24 Tg, and the mean BGB density and shrublands area were 1,567.38 g/m² and 4.29 × 10⁴ km², respectively. Shrub layer had a larger BGB stock and accounted for 66% of total BGB this area, while only 34% was accumulated in the grass layer. BGB of the grass layer in the Tibetan Plateau shrublands was larger than that of Tibetan alpine grasslands, indicating that shrubland ecosystem played a critical importance role in carbon cycle on the Tibetan Plateau. The BGB in the grass layer and shrub layer demonstrated different correlations with climatic factors. Specifically, the effects from mean annual temperature on shrub-layer BGB were not significant, similarly to the relationship between mean annual precipitation and grass-layer BGB. But shrub-layer BGB had a significantly positive relationship with mean annual precipitation (p < .05), while grass-layer BGB showed a trend of decrease with increasing mean annual temperature (p < .05). Consequently, the actual and potential increases of BGB varied due to different increases of mean annual precipitation and temperature among different areas of the Tibetan Plateau. Therefore, in the warmer and wetter scenario, due to contrary relationships from mean annual precipitation and temperature on shrub-layer BGB and grass-layer BGB, it is necessary to conduct a long-term monitoring about dynamic changes to increase the precision of assessment of BGB carbon sequestration in the Tibetan Plateau alpine shrublands.

Keywords: Tibetan Plateau; alpine shrublands; belowground biomass; mean annual precipitation; mean annual temperature.

Associated data

Dryad/10.5061/dryad.kh189322v