Abstract:
Mineral protection mechanisms are important in determining the response of particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) to temperature changes. However, the underlying mechanisms for how POC and MAOC respond to temperature changes are remain unclear. By translocating soils across 1304 m, 1425 m and 2202 m elevation gradient in a temperate forest, simulate nine months of warming (with soil temperature change of +1.41 °C and +3.91 °C) and cooling (with soil temperature change of -1.86 °C and -4.20 °C), we found that warming translocation significantly decreased POC by an average of 10.84 %, but increased MAOC by an average of 4.25 %. Conversely, cooling translocation led to an average increase of 8.64 % in POC and 13.48 % in MAOC. Exchangeable calcium (Caexe) had a significant positive correlation with POC and MAOC during temperature changes, and Fe/Al-(hydr)oxides had no significant correlation or a significant negative correlation with POC and MAOC. Our results showed that POC was more sensitive than MAOC to temperature changes. Caexe mediated the stability of POC and MAOC under temperature changes, and Fe/Al-(hydr)oxides had no obvious protective effect on POC and MAOC. Our results support the role of mineral protection in the stabilization mechanism of POC and MAOC in response to climate change and are critical for understanding the consequences of global change on soil organic carbon (SOC) dynamics.
摘要:
矿物保护机制对于确定颗粒有机碳(POC)和矿物相关有机碳(MAOC)对温度变化的响应很重要。然而,POC和MAOC对温度变化的反应机制尚不清楚.通过将土壤转移到1304米,温带森林的海拔梯度为1425m和2202m,模拟9个月的增温(土壤温度变化为+1.41°C和+3.91°C)和降温(土壤温度变化为-1.86°C和-4.20°C),我们发现,变暖易位显著降低POC平均10.84%,但MAOC平均增加了4.25%。相反,冷却移位导致POC平均增加8.64%,MAOC平均增加13.48%。在温度变化过程中,可交换钙(Caexe)与POC和MAOC呈显著正相关,Fe/Al-(hyr)氧化物与POC和MAOC无显著相关性或显著负相关。我们的结果表明,POC比MAOC对温度变化更敏感。Caexe介导POC和MAOC在温度变化下的稳定性,Fe/Al-(氢)氧化物对POC和MAOC无明显保护作用。我们的结果支持矿物保护在POC和MAOC响应气候变化的稳定机制中的作用,并且对于理解全球变化对土壤有机碳(SOC)动力学的影响至关重要。