Key Laboratory of Resource Plants, Beijing Botanical Garden, West China Subalpine Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, China.
PLoS One. 2013 Jul 16;8(7):e70224. doi: 10.1371/journal.pone.0070224. Print 2013.
It is generally predicted that global warming will stimulate primary production and lead to more carbon (C) inputs to soil. However, many studies have found that soil C does not necessarily increase with increased plant litter input. Precipitation has increased in arid central Asia, and is predicted to increase more, so we tested the effects of adding fresh organic matter (FOM) and water on soil C sequestration in an arid region in northwest China. The results suggested that added FOM quickly decomposed and had minor effects on the soil organic carbon (SOC) pool to a depth of 30 cm. Both FOM and water addition had significant effects on the soil microbial biomass. The soil microbial biomass increased with added FOM, reached a maximum, and then declined as the FOM decomposed. The FOM had a more significant stimulating effect on microbial biomass with water addition. Under the soil moisture ranges used in this experiment (21.0%-29.7%), FOM input was more important than water addition in the soil C mineralization process. We concluded that short-term FOM input into the belowground soil and water addition do not affect the SOC pool in shrubland in an arid region.
普遍预测，全球变暖将刺激初级生产，并导致更多的碳（C）输入土壤。然而，许多研究发现，土壤 C 不一定随植物凋落物输入的增加而增加。中亚干旱地区的降水量增加，预计还会增加更多，因此我们测试了在我国西北地区干旱地区添加新鲜有机物（FOM）和水对土壤 C 固存的影响。结果表明，添加的 FOM 迅速分解，对 30 厘米深的土壤有机碳（SOC）库影响较小。FOM 和水分的添加均对土壤微生物生物量有显著影响。随着添加的 FOM，土壤微生物生物量增加，达到最大值，然后随着 FOM 的分解而下降。FOM 与水分添加结合对微生物生物量的刺激作用更为显著。在本实验中使用的土壤水分范围内（21.0%-29.7%），FOM 输入在干旱地区灌丛土壤的碳矿化过程中比水分添加更为重要。我们得出结论，短期 FOM 输入到地下土壤和水分添加不会影响干旱地区灌丛的 SOC 库。
