中国亚热带重要树种植硅体碳封存潜力估测

研究选取中国亚热带阔叶林、针叶林、竹林等3 种森林类型中常见的7 个树种,通过微波消解法提取其植硅体,并对其植硅体中碳含量进行测定,计算植硅体产量并估测碳封存量,结果表明:① 7个树种叶子植硅体碳占干物质含量分别为毛竹3.31±0.53 g·kg^-1、杉木0.30±0.06 g·kg^-1、马尾松0.40±0.11 g·kg^-1、苦槠0.19±0.04 g·kg^-1、青冈0.88±0.09 g·kg^-1、木荷0.49±0.18 g·kg^-1、枫香1.12±0.33 g·kg^-1;② 相关分析表明,硅与植硅体含量(P<0.05,R²=0.989 7)、植硅体与植硅体碳占物质含量(P<0.05,R²=0.881 6)、植硅体碳与植硅体碳占干物质含量(P<0.05,R²=0.354 4)之间的相关性达显著水平.③ 毛竹的植硅体碳封存速率最高,若以最高植硅体碳封存速率0.050 6t- e-CO₂·hm^-2·a^-1计算,面积为3.87×10⁶ hm²的毛竹林每年可封存约1.96×10⁵ t CO₂;④ 杉木、马尾松的植硅体碳封存速率分别为0.005 6 和0.010 8 t-e-CO₂ ·hm^-2 ·a^-1,面积分别为1.13×10⁷、1.20×10⁷ hm²的杉木林、马尾松林每年可封存约6.33×10⁴、1.30×10⁵ t CO₂;⑤ 阔叶林植硅体碳封存速率介于0.000 5~0.019 3 t-e-CO₂·hm^-2·a^-1之间,面积为2.49×10⁷ hm²的阔叶林每年可封存1.25×10⁴~48.15×10⁴ t CO₂.

Estimation of Sequestration Potential via Phytolith Carbon by Important Forest Species in Subtropical China

In this study, seven tree species including broad-leaved forest, coniferous forest, and bamboo forest in subtropical China were selected as experimental materials. The phytolith in the plants was extracted through a microwave digestion method and the phytolith occluded carbon (PhytOC) concentrations in the leaves were determined. The results showed that: 1) all the seven tree species had the potential of carbon bio-sequestration within phytoliths. The PhytOC concentrations in dry leaf biomass of different tree species were in the following order: Phyllostachys pubescens (3.31 ± 0.53 g·kg^-1) > Liquidambar formosana (1.12 ± 0.33 g·kg^-1) > Cyclobalanopsis glaua (0.88 ± 0.09 g·kg^-1) > Schima superba (0.49 ± 0.18 g·kg^-1) > Pinus massoniana (0.40 ± 0.11 g·kg^-1) > Cunninghamia lanceolata (0.30 ± 0.06 g·kg^-1) > Castanopsis sclerophylla (0.19 ± 0.04 g·kg^-1). 2) There were strong linear relationships between Si concentrations and phytolith concentrations (P<0.05, R²=0.9897), phytolith concentrations and PhytOC concentrations in the leaf dry weight (P<0.05, R²=0.8816), PhytOC concentrations in phytoliths and PhytOC in the leaf dry weight (P<0.05, R²=0.3544). 3) Phyllostachys pubescens had the highest PhytOC fluxes (0.0506 t-e-CO₂·hm^-2·a^-1), bio-sequestration via phytolith carbon from leaf-litter under 3.87×10⁶ hm² of Phyllostachys pubescens stands in subtropical China is estimated to be about 1.96×10⁵ t CO₂. 4) The phytoliths carbon bio- sequestration flux of Cunninghamia lanceolata and Pinus massoniana were 0.0056 and 0.0108 t-e-CO₂·hm^-2·a^-1, respectively, bio-sequestration via phytolith carbon from leaf-litter under 1.13×10⁷ and 1.20×10⁷ hm² of Cunninghamia lanceolata and Pinus massoniana stands is estimated to be about about 6.33×10⁴ and 1.30 × 10⁵t CO₂, respectively. 5) The phytoliths carbon bio- sequestration flux of broadleaved forests ranged from 0.0005 to 0.0193 t-e-CO₂·hm^-2, bio-sequestration via phytolith carbon from leaf-litter under 2.49×10⁷ hm² of broad-leaved forests in subtropical China is estimated to be about 1.25×10⁴-48.15×10⁴ t CO₂.