Institute of the Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
College of Urban and Environmental Sciences, Peking University, Peking 100871, China.
Sci Total Environ. 2017 Dec 15;603-604:502-509. doi: 10.1016/j.scitotenv.2017.06.107. Epub 2017 Jun 20.
Terrestrial biogeochemical carbon (C) sequestration is coupled with the biogeochemical silicon (Si) cycle through mechanisms such as phytolith C sequestration, but the size and distribution of the phytolith C sink remain unclear. Here, we estimate phytolith C sequestration in global terrestrial biomes. We used biome data including productivity, phytolith and silica contents, and the phytolith stability factor to preliminarily determine the size and distribution of the phytolith C sink in global terrestrial biomes. Total phytolith C sequestration in global terrestrial biomes is 156.7±91.6TgCOyr. Grassland (40%), cropland (35%), and forest (20%) biomes are the dominant producers of phytolith-based carbon; geographically, the main contributors are Asia (31%), Africa (24%), and South America (17%). Practices such as bamboo afforestation/reforestation and grassland recovery for economic and ecological purposes could theoretically double the above phytolith C sink. The potential terrestrial phytolith C sequestration during 2000-2099 under such practices would be 15.7-40.5PgCO, equivalent in magnitude to the C sequestration of oceanic diatoms in sediments and through silicate weathering. Phytolith C sequestration contributes vitally to the global C cycle, hence, it is essential to incorporate plant-soil silica cycling in biogeochemical C cycle models.
陆地生物地球化学碳（C）封存通过植物硅酸体 C 封存等机制与生物地球化学硅（Si）循环耦合，但植物硅酸体 C 汇的规模和分布仍不清楚。在这里，我们估计了全球陆地生物群系中的植物硅酸体 C 封存。我们使用包括生产力、植物硅酸体和硅含量以及植物硅酸体稳定性因子在内的生物群系数据，初步确定了全球陆地生物群系中植物硅酸体 C 汇的规模和分布。全球陆地生物群系中植物硅酸体总碳封存量为 156.7±91.6TgCOyr。草原（40%）、农田（35%）和森林（20%）生物群系是基于植物硅酸体的碳的主要生产者；在地理上，主要贡献者是亚洲（31%）、非洲（24%）和南美洲（17%）。出于经济和生态目的进行竹子造林/再造林和草原恢复等实践，理论上可以使上述植物硅酸体 C 汇增加一倍。在这些实践下，2000-2099 年期间潜在的陆地植物硅酸体 C 封存量将达到 15.7-40.5PgCO，与海洋硅藻在沉积物中的碳封存和通过硅酸盐风化的碳封存相当。植物硅酸体 C 封存对全球 C 循环至关重要，因此，必须将植物-土壤硅循环纳入生物地球化学 C 循环模型中。
