Data from: Changes in ecosystem carbon stocks following grazing exclusion in arid and semiarid grasslands
Yu, Lingfei; Sun, Wenjuan; Huang, Yao (2020), Data from: Changes in ecosystem carbon stocks following grazing exclusion in arid and semiarid grasslands, Dryad, Dataset, https://doi.org/10.5061/dryad.cfxpnvx3h
- Grazing exclusion (GE) is widely considered to be an important strategy for restoring overgrazed grasslands and promoting carbon (C) storage. However, the changes in the components of ecosystem C with GE and their related drivers remain largely unexplored.
- Here, we investigated the effects of GE on the ecosystem C components (plant and soil C) and their key driving factors through sampling inside and outside 15 grazing exclosures across the Inner Mongolia arid and semiarid grasslands in northern China.
- Our results showed that, except for dead root C, GE significantly promoted plant C stocks. The increase in AGB and litter C stocks resulted from the accumulation of both biomass and C concentration, while the increase in live root C stock was mainly attributed to biomass accumulation. In contrast, although the topsoil soil C concentration (0-20 cm) showed a marginal increase following GE, its bulk density greatly declined, which resulted in little change in the soil C stocks. Overall, GE had no significant effect on total ecosystem C stocks. Our results further indicated that across the grasslands, GE likely enhanced C accumulation in live roots in humid and fertile sites, while it caused losses of dead root C in relatively humid and fertile sites and increases in arid and infertile sites.
- We also found that the increases in AGB C, litter C and live root C stocks were driven by the direct effects of GE and its indirect effects mediated by soil water content. The marginal increases in soil C concentration with GE were linked to only high soil water contents. Meta-analysis further revealed that across the grasslands of China, the responses of ecosystem C components to GE were associated with changes in soil water conditions, suggesting the generality of soil water effects at the national scale.
- Overall, our results showed that across arid and semiarid grasslands, GE is generally beneficial for plant C accumulation but has little effect on soil C stocks. Importantly, our study highlighted the important role of soil water in regulating ecosystem C dynamics with GE across the grasslands of China.