微生物种群生物学
土壤碳
土壤有机质
生态系统
植被(病理学)
农学
生态学
环境科学
溶解有机碳
有机质
负启动
温带森林
自行车
营养循环
生物
土壤水分
林业
细菌
地理
医学
遗传学
认知
病理
神经科学
选择性注意
作者
Hongfei Liu,Callum C. Banfield,Sofia I. F. Gomes,Matthias Gube,Alfons Weig,Johanna Pausch
标识
DOI:10.1016/j.soilbio.2023.109123
摘要
Meadows and forests are the main vegetation types in temperate terrestrial ecosystems, and largely contribute to soil carbon (C) stock. Bioavailable C inputs can accelerate microbial decomposition of soil organic matter (SOM), which is known as “priming effect”. However, it is still unclear how priming effect, as an important mechanism influencing soil C sequestration, is influenced by spatial transition of vegetation from meadow to forest. To investigate the mechanism of priming effect along a spatial transition gradient of vegetation, a soil incubation experiment with 14C labeled glucose was combined with microbial rDNA sequencing and gene composition prediction. The results showed that with the vegetation transition from meadow to forest soil available phosphorus (P) significantly increased, in contrast to dissolved nitrogen (N) and C which remained unaffected. Moreover, the soil microbial community composition shifted towards a higher relative abundance of K-strategists (Acidobacteria) and a lower abundance of r-strategists (Actinobacteriota) along the vegetation transition from meadow to forest. In the meadow, the microbial community consumed more of the added glucose and increased priming effect. This was accompanied by lower available P but higher soil bacterial gene function encoding P cycling. In contrast, increased soil P availability in forest soils caused a decelerated microbial metabolism of phosphorylated organic compounds within microbial biomass due to decreased microbial demand for P acquisition from SOM, and thus resulted in suppression of the priming effect. Our study showed that P availability and microbial community shifts in spatial transition zones between meadows and forests are important drivers for the priming effect on SOM decomposition.
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