Response of Soil Carbon and Nitrogen to 15-year Experimental Warming in Two Alpine Habitats (Kobresia Meadow and Potentilla Shrubland) on the Qinghai-Tibetan Plateau

Abstract

Although the Qinghai-Tibetan Plateau (QTP) has experienced striking warming during the past century, information on how soil carbon (C) and nitrogen (N) pools of the alpine regions on the QTP respond to long-term warming is scarce. The aims of this study were to assess the response of soil organic C (SOC), total N (TN), labile C and N -including microbial biomass C (MBC) and N (MBN), inorganic N (N inorg ), dissolved organic C (DOC), and N (DON) -to 15-year experimental warming in an alpine region (Kobresia meadow and Potentilla scrubland), on the northeastern QTP using open-top chambers (OTCs). Fifteen-year experimental warming had no effect on SOC and TN concentrations and storage at 0-30 cm soil depth, either in Kobresia meadow or Potentilla scrubland habitat, which might be related to the low temperature increase and the unchanged water content. Long-term warming obviously affected soil labile C and N and their contributions to SOC and TN, especially in the meadow habitat, but the values were low, thus the variation of the labile C and N was not enough to influence total C and N storage. The C and N pools were shown to be controlled by different controlling factors, and scrubland was more stable than the meadow ecosystem confronting the change of environment.

Short-Term Response of the Soil Microbial Abundances and Enzyme Activities to Experimental Warming in a Boreal Peatland in Northeast China

“…One possible explanation for this result is that the cell reserves and labile substrates for microbes are depleted under warming [46]. The results of our study indicated that warming exerted no evident effect on soil TC, which is consistent with the results of Chen et al [47]. They found that 5 and 15 years of warming did not affect the SOC pool because of high soil carbon levels.…”

“…They found that 5 and 15 years of warming did not affect the SOC pool because of high soil carbon levels. Although warming influences MBC and DOC, the proportions of these labile organic carbon (LOC) in the total SOC pool are low; thus, the variation in labile carbon is insufficient to influence the total carbon storage [47]. In addition, warming could decrease microbial decomposing capacity to recalcitrant carbon, and then ameliorate soil carbon loss [48].…”

Responses of soil C pools to combined warming and altered precipitation regimes: A meta‐analysis

“…Decreased precipitation, however, may exacerbate warming‐induced soil drought, which would not only decrease C input, but also inhibit SOM decomposition due to increased physical protection (German & Allison, 2015; Wang, An, et al, 2021). These contrasting results are highly dependent on ecosystem types, experimental durations and edaphic characteristics (Chen et al, 2016; Ganjurjav et al, 2016). Hence, an analysis across multiple ecosystem types with heterogeneous climatic conditions is needed to adequately assess the combined effects of warming and altered precipitation on SOC at the global scale.…”

Restoration Measures Supported Surface Soil Carbon and Nitrogen Density in Alpine Grassland of Sanjiangyuan Region, China

“…There are many studies on soil C and N, mainly involving the effects of land use [7][8][9], management measures [10][11][12], restoration measures [13][14][15][16][17][18][19] on soil C and N, and the relationship between plant functional groups and soil factors [20][21][22]. However, most related research in China has been concentrated in the Loess Plateau area [10, 13-14, 17, 19, 22], but few studies have focused on alpine regions -especially the Sanjiangyuan region [12,18,[23][24][25]. Based on the above grassland restoration background, we investigated the changes of C and N in grassland soil under different restoration measures in the Sanjiangyuan region.…”