DOI: 10.5061/dryad.kh189322v
title: The grass-layer (BGB) and shrub-layer (BGB) data across the northeast Tibetan Plateau shrublands

description: 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 m-2 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&lt;0.05), while grass-layer BGB showed a trend of decrease with
 increasing mean annual temperature (P&lt;0.05). 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.
description: A total of 147 plots were collected across 49 sites (i.e., each
 site including three plots) in the Tibetan Plateau shrublands during the
 period of July and August from 2011 to 2013. The distance was between 5 m
 and 50 m between any two plots. Each plot of 5 m × 5 m was used for
 ecological investigation, such as definite dominant species. According to
 the sampling method for shrubland ecosystem, the sampling size should be
 not smaller than 1 m × 1 m (Technical Manual Writing Group of Ecosystem
 Carbon Sequestration Project, 2015). one subplot of 1 m × 1 m was sampled,
 and the total of all plants in the subplots was dug up to determine BGB.
 Generally, we dug a pit of 1 m depth, or we dug until the parent material
 horizon to collect root samples. The BGB comprised biomass including the
 grass layer and the shrub layer. Grass and shrub roots grow together in
 each plot, and based on lignify of BGB, we separated them in each plot.
 The criteria of distinguishing grass and shrub root were whether they are
 herbs or woody. Specifically, the shrub layer primarily consisted of woody
 biomass, while grass layer composed by herbs biomass. Meanwhile, combining
 with AGB, we can easily distinguish grass-layer BGB and shrub-layer BGB.
 Then, we only retained root sample and cleaned up the other parts
 (Technical Manual Writing Group Of Ecosystem Carbon Sequestration Project,
 2015). The biomass samples were all weighed to the nearest 0.01 g after it
 was oven-dried to a constant mass at 65°C. The BGB in the grass layer and
 shrub layer were shown in Table 1.
description: # The grass-layer (BGB) and shrub-layer (BGB) data across the northeast
 Tibetan Plateau shrublands
 [https://doi.org/10.5061/dryad.kh189322v](https://doi.org/10.5061/dryad.kh189322v) ## Description of the data A total of 147 plots were collected across 49 sites (i.e., each site including three plots) in the Tibetan Plateau shrublands during the period of July and August from 2011 to 2013. The distance was between 5 m and 50 m between any two plots. Each plot of 5 m × 5 m was used for ecological investigation, such as definite dominant species. According to the sampling method for shrubland ecosystem, the sampling size should be not smaller than 1m × 1 m (Technical Manual Writing Group of Ecosystem Carbon Sequestration Project, 2015). Due to the limited manpower and financial resources, in the each plot, one subplot of 1 m × 1 m was sampled, and the total of all plants in the subplots was dug up to determine BGB. Generally, we dug a pit of 1 m depth, or we dug until the parent material horizon to collect root samples. The BGB comprised biomass including the grass layer and the shrub layer. Grass and shrub roots grow together in each plot, and based on lignify of BGB, we separated them in each plot. The criteria of distinguishing grass and shrub root were whether they are herbs or woody. Specifically, the shrub layer primarily consisted of woody biomass, while grass layer composed by herbs biomass. Meanwhile, combining with AGB, we can easily distinguish grass-layer BGB and shrub-layer BGB. Then, we only retained root sample and cleaned up the other parts (Technical Manual Writing Group Of Ecosystem Carbon Sequestration Project, 2015). The biomass samples were all weighed to the nearest 0.01 g after it was oven-dried to a constant mass at 65°C. ## Description of the variables File: EE_upload.csv Variables: * latitude: The latitudinal coordinate of the plot * longitude: The longitudinal coordinate of the plot * Grass layer BGB (gm-2): The grass layer BGB (gm-2) of the plot * Shrub layer BGB (gm-2): The Shrub layer BGB (gm-2) of the plot