Soil and Ecosystem Ecology Laboratory, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
Ecol Lett. 2011 May;14(5):493-502. doi: 10.1111/j.1461-0248.2011.01611.x. Epub 2011 Mar 14.
Understanding the factors that drive soil carbon (C) accumulation is of fundamental importance given their potential to mitigate climate change. Much research has focused on the relationship between plant traits and C sequestration, but no studies to date have quantitatively considered traits of their mycorrhizal symbionts. Here, we use a modelling approach to assess the contribution of an important mycorrhizal fungal trait, organic nutrient uptake, to soil C accumulation. We show that organic nutrient uptake can significantly increase soil C storage, and that it has a greater effect under nutrient-limited conditions. The main mechanism behind this was an increase in plant C fixation and subsequent increased C inputs to soil through mycorrhizal fungi. Reduced decomposition due to increased nutrient limitation of saprotrophs also played a role. Our results indicate that direct uptake of nutrients from organic pools by mycorrhizal fungi could have a significant effect on ecosystem C cycling and storage.
理解驱动土壤碳（C）积累的因素至关重要，因为它们有可能缓解气候变化。许多研究都集中在植物特性与碳固存之间的关系上，但迄今为止尚无研究定量考虑其菌根共生体的特性。在这里，我们使用建模方法来评估重要的菌根真菌特性——有机养分吸收对土壤 C 积累的贡献。我们表明，有机养分吸收可以显著增加土壤 C 储存，并且在养分有限的条件下效果更大。这背后的主要机制是植物 C 固定的增加，随后通过菌根真菌向土壤中增加 C 输入。由于增加了对分解者的养分限制，导致分解减少，也起到了一定的作用。我们的研究结果表明，菌根真菌直接从有机库中吸收养分可能会对生态系统 C 循环和储存产生重大影响。
