Phytolith carbon sequestration in global terrestrial biomes

Sci Total Environ. 2017 Dec 15:603-604:502-509. doi: 10.1016/j.scitotenv.2017.06.107. Epub 2017 Jun 20.

Abstract

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±91.6TgCO2yr-1. 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 15.7-40.5PgCO2, 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.

Keywords: Biogeochemical carbon sequestration; Carbon sink; Phytolith-occluded carbon (PhytOC); Silicon; Terrestrial biomes.

MeSH terms

  • Africa
  • Agriculture*
  • Asia
  • Carbon
  • Carbon Sequestration*
  • Crops, Agricultural / metabolism
  • Forests*
  • Grassland*
  • Models, Theoretical
  • Plants / metabolism*
  • South America

Substances

  • Carbon