作者: Mei Liu, Jiahao Wen, Yamei Chen, Wenjuan Xu, Qiong Wang, Zhiliang Ma

Abstract: Plant-derived carbon (C) inputs via foliar litter, root litter and root exudates are key drivers of soil organic C stocks. However, the responses of these three input pathways to climate warming have rarely been studied in alpine shrublands. By employing a 3-year warming experiment (increased by 1.3℃), we investigated the effects of warming on the relative C contributions from foliar litter, root litter and root exudates from Sibiraea angustata, a dominant shrub species in an alpine shrubland on the eastern Qinghai-Tibetan Plateau. The soil organic C inputs from foliar litter, root litter and root exudates were 77.45, 90.58 and 26.94 g C m^-2,respectively.Warming only slightly increased the soil organic C inputs from foliar litter and root litter by 8.04 and 11.13 g C m^-2,but significantly increased the root exudate C input by 15.40 g C m^-2.Warming significantly increased the relative C contributions of root exudates to total C inputs by 4.6%but slightly decreased those of foliar litter and root litter by 2.5% and 2.1%, respectively. Our results highlight that climate warming may stimulate plant-derived C inputs into soils mainly through root exudates rather than litter in alpine shrublands on the Qinghai-Tibetan Plateau.

Keywords: soil organic carbon, foliar litter, root litter, root exudates, climate warming, alpine shrub, Qinghai-Tibetan Plateau

DOI: 10.1093/jpe/rtab101