奇立敏等在Science of the Total Environment发表研究论文

实验室博士研究生奇立敏等在Science of the Total Environment（IF=4.0，环境科学与生态学大类二区）上发表题为Phytolith-occluded organic carbon as a mechanism for long-term carbon sequestration in a typical steppe: The predominant role of belowground productivity的研究论文。实验室李永宏教授为该论文通讯作者，宝音教授为共同作者。

论文摘要如下：

Abstract

Phytolith-occluded organic carbon (phytOC) has recently been demonstrated to be an important terrestrial carbon (C) fraction resistant to decomposition and thus has potential for long-term C sequestration. Existing studies show that plant leaves and sheath normally have high phytOC concentration, thus most of phytOC studies are limited to the aboveground plant parts. Grassland communities comprise herbaceous species, especially grasses and sedges which have relatively high concentrations of phytoliths, but the phytOC production from grassland, especially from its belowground part, is unknown. Here we determined the phytOC concentration in different parts of major plant species in a typical steppe grassland on the Mongolian Plateau, and estimated the phytolith C sequestration potential. We found that the phytOC concentration of major steppe species was significantly (p < 0.05) higher in belowground (0.67 g kg− 1) than aboveground biomass (0.20 g kg− 1) and that the belowground net primary productivity (BNPP) was 8–15 times the aboveground net primary productivity (ANPP). Consequently, the phytOC stock in belowground biomass (12.50 kg ha− 1) was about 40 times of that in aboveground biomass (0.31 kg ha− 1), and phytOC production flux from BNPP (8.1–15.8 kg ha− 1 yr− 1) was 25–51 times of that from ANPP. Our results indicate that BNPP plays a dominant role in the biogeochemical silica cycle and associated phytOC production in grassland ecosystems, and suggests that potential phytolith C sequestration of grasslands may be at least one order of magnitude greater than the previous estimation based on ANPP only. Our results emphasize the need for more research on phytolith and phytOC distribution and flux in both above and below ground plant parts for quantifying the phytolith C sequestration.

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