当前位置: X-MOL 学术Glob. Change Biol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Towards an ecosystem capacity to stabilise organic carbon in soils
Global Change Biology ( IF 10.8 ) Pub Date : 2024-08-05 , DOI: 10.1111/gcb.17453
Christopher Poeplau 1 , Rene Dechow 1 , Neha Begill 1 , Axel Don 1
Affiliation  

Soil organic carbon (SOC) accrual, and particularly the formation of fine fraction carbon (OCfine), has a large potential to act as sink for atmospheric CO2. For reliable estimates of this potential and efficient policy advice, the major limiting factors for OCfine accrual need to be understood. The upper boundary of the correlation between fine mineral particles (silt + clay) and OCfine is widely used to estimate the maximum mineralogical capacity of soils to store OCfine, suggesting that mineral surfaces get C saturated. Using a dataset covering the temperate zone and partly other climates on OCfine contents and a SOC turnover model, we provide two independent lines of evidence, that this empirical upper boundary does not indicate C saturation. Firstly, the C loading of the silt + clay fraction was found to strongly exceed previous saturation estimates in coarse‐textured soils, which raises the question of why this is not observed in fine‐textured soils. Secondly, a subsequent modelling exercise revealed, that for 74% of all investigated soils, local net primary production (NPP) would not be sufficient to reach a C loading of 80 g C kg−1 silt + clay, which was previously assumed to be a general C saturation point. The proportion of soils with potentially enough NPP to reach that point decreased strongly with increasing silt + clay content. High C loadings can thus hardly be reached in more fine‐textured soils, even if all NPP would be available as C input. As a pragmatic approach, we introduced texture‐dependent, empirical maximum C loadings of the fine fraction, that decreased from 160 g kg−1 in coarse to 75 g kg−1 in most fine‐textured soils. We conclude that OCfine accrual in soils is mainly limited by C inputs and is strongly modulated by texture, mineralogy, climate and other site properties, which could be formulated as an ecosystem capacity to stabilise SOC.

中文翻译:


建立稳定土壤有机碳的生态系统能力



土壤有机碳 (SOC) 累积,特别是细粒碳 (OC) 的形成美好的),具有作为大气二氧化碳汇的巨大潜力2 。为了可靠地估计这种潜在且有效的政策建议,OC 的主要限制因素美好的需要理解应计。细矿物颗粒(粉土+粘土)与 OC 相关性的上界美好的广泛用于估计土壤储存 OC 的最大矿物学能力美好的,表明矿物表面碳饱和。在 OC 上使用涵盖温带和部分其他气候的数据集美好的内容和 SOC 周转模型,我们提供了两条独立的证据,表明该经验上限并不表明 C 饱和度。首先,我们发现粉土+粘土部分的碳负荷大大超过了之前粗质地土壤中饱和度的估计,这就提出了一个问题:为什么在细质地土壤中没有观察到这种情况。其次,随后的建模练习显示,对于所有调查土壤中的 74%,当地净初级生产力 (NPP) 不足以达到 80 g C kg 的 C 负荷−1粉土+粘土,之前被假定为一般的 C 饱和点。随着淤泥+粘土含量的增加,具有潜在足够NPP达到该点的土壤比例急剧下降。因此,即使所有 NPP 都可以作为 C 输入,在更细质地的土壤中也很难达到高 C 负荷。 作为一种实用的方法,我们引入了细粒部分的依赖于纹理的经验最大 C 负载量,该负载量从 160 g kg −1粗至 75 g kg −1在大多数细质地土壤中。我们的结论是 OC美好的土壤中的累积量主要受到碳输入的限制,并受到质地、矿物学、气候和其他场地特性的强烈调节,这些特性可以表述为稳定 SOC 的生态系统能力。
更新日期:2024-08-05
down
wechat
bug