Sympodial bamboo species differ in carbon bio-sequestration and stocks within phytoliths of leaf litters and living leaves.

Abstract

Phytolith-occluded carbon (PhytOC) with high resistance against decomposition is an important carbon (C) sink in many ecosystems. This study compared concentrations of phytolith in plants and the PhytOC production of seven sympodial bamboo species in southern China, aiming to provide the information for the managed bamboo plantation and selection of bamboo species to maximize phytolith C sequestration. Leaf litters and living leaves of seven sympodial bamboo species were collected from the field sites. Concentrations of phytoliths, silicon (Si), and PhytOC in leaf litters and living leaves were measured. Carbon sequestration as PhytOC was estimated. There was a considerable variation in the PhytOC concentrations in the leaf litters and living leaves among the seven bamboo species. The mean concentrations of PhytOC ranged from 3.4 to 6.9gkg(-1) in leaf litters and from 1.6 to 5.9gkg(-1) in living leaves, with the PhytOC production rates ranging from 5.7 to 52.3kg e-CO2 ha(-1)year(-1) as leaf litters. Dendrocalamopsis oldhami (Munro) Keng f. had the highest PhytOC production rate. Based on a bio-sequestration rate of 52.3kg e-CO2 ha(-1)year(-1), we estimated that the current 8 × 10(5)ha of sympodial bamboo stands in China could potentially acquire 4.2 × 10(4)t e-CO2 yearly via phytolith carbon. Furthermore, the seven sympodial bamboo species stored 5.38 × 10(5)t e-CO2 as PhytOC in living leaves and leaf litters in China. It is concluded that sympodial bamboos make a significant contribution to C sequestration and that to maximize the PhytOC accumulation, the bamboo species with the highest PhytOC production rate should be selected for plantation.