软体动物,第二大动物家族,存在于各种生态系统中。随着他们的成长,它们的外壳吸收碳并形成碳酸钙,使它们成为碳的重要储存场所。然而,在整个现代和地质历史中,陆生软体动物的碳酸盐壳中沉积的碳含量尚未量化。在这项研究中,我们首先对中国不同陆地生态系统的470个现代表层土壤样品点的各种软体动物贝壳中的碳沉积物进行了调查。落叶阔叶林和灌木的碳沉积速率较高,分别为〜1.37±2.15和〜1.56±2.92gCm-2/yr-1,而农田和草地的碳沉积速率分别为〜1.11±1.95和1.07±1.78gCm-2/yr-1。使用地统计学方法,我们估计了草地的壳碳沉积总量,森林,灌木丛,中国的农田为〜3.39-5.45×106tCyr-1,占中国陆地碳汇的〜1.68-2.71%,在以前的研究中被忽视的部分。此外,我们通过黄土矿床的十多个化石序列提供了长达20,000年的壳碳通量的定量数据。结果强调了软体动物贝壳在不同地点的连续和丰富的碳沉积至少2万年,突出了贝壳碳沉积物的持久性和大量积累。值得注意的是,我们估计近2万年来中国和世界黄土沉积物的壳碳沉积总量可能达到1.10×108tC和1.29×109tC,大致相当于造林面积分别为2.32×106km2和2.72×107km2。
Mollusks, the second largest animal family, are found in a variety of ecosystems. As they grow, their shells absorb carbon and form calcium carbonate, making them an important storage place for carbon. However, the amount of carbon deposited in the carbonate shells of terrestrial mollusks throughout modern and geological history has not been quantified. In this study, we first conducted an investigation of carbon deposits in shells from various mollusk species at 470 modern surface soil sample sites across diverse terrestrial ecosystems in China. The deciduous broadleaf forest and shrublands exhibited a higher carbon deposition rate of ∼1.37 ± 2.15 and ∼1.56 ± 2.92 g C m-2/yr-1, while croplands and grasslands displayed a rate of ∼1.11 ± 1.95 and 1.07 ± 1.78 g C m-2/yr-1, respectively. Using geostatistical methods, we estimated the total shell carbon deposition of grassland, forest, shrublands, and croplands in China to be ∼3.39-5.45 × 106 t C yr-1, constituting ∼1.68-2.71 % of China\'s terrestrial carbon sink, an overlooked portion in previous studies. Additionally, we provided quantitative data on shell carbon fluxes spanning a remarkable 20,000-year period through over ten fossil sequences from loess deposits. The results underscore the continuous and abundant carbon deposition in mollusk shells across various locations for at least 20,000 years, highlighting the persistence and substantial accumulation of shell carbon deposits over time. Remarkably, we estimated that the total shell carbon deposition of loess sediments in China and the world over the past 20,000 years may reach 1.10 × 108 t C and 1.29 × 109 t C, roughly equivalent to an afforestation area of 2.32 × 106 km2 and 2.72 × 107 km2, respectively.