Stable isotopes reveal that fungal residues contribute more to mineral-associated organic matter pools than plant residues
Stable isotopes reveal that fungal residues contribute more to mineral-associated organic matter pools than plant residues
复制标题
DOI：
10.1016/j.soilbio.2022.108634
复制
发表时间：
2022-05-01
影响因子：
9.7
通讯作者：
Pausch, Johanna
中科院分区：
文献类型：
--
作者：
Klink, Saskia;Keller, Adrienne B.;Pausch, Johanna
我们仍然缺乏关于植物和微生物残留物对特定SOM库的贡献的关键知识，特别是丛枝（AM），外生菌根（ECM）和腐生性（SAP）真菌的相对贡献。（POM和MAOM）在具有不同菌根类型的树木周围，鹅掌楸（AM-协会）和栎alba（ECM-协会），在一个温带落叶林在印第安纳州，美国。结合13 C和15 N天然丰度分析和氨基糖法测定微生物残留，比较了大、中、小型POM和MAOM组分与菌根和腐解营养真菌的叶、根和生物量的同位素特征。贝叶斯推断同位素混合模型计算的C和N的SOM组分的来源。虽然POM的同位素组成类似于植物，MAOM接近真菌值。混合模型计算和微生物残留分析证实了这一点，另外，独立于树木伙伴的结果表明，腐殖真菌对POM的贡献为4-53%，对MAOM的贡献为23-42%，而ECM的贡献则相反。因此，改变真菌群落可以增强增加土壤碳长期储存的努力。
We still lack crucial knowledge about the contribution of plant vs. microbial residues to specific SOM pools, particularly the relative contribution of arbuscular (AM), ectomycorrhizal (ECM), and saprotrophic (SAP) fungi.We investigated sources of particulate and mineral-associated organic matter (POM and MAOM) around trees with distinct mycorrhizal types, Liriodendron tulipifera (AM-association) and Quercus alba (ECM-association), in a temperate deciduous forest in Indiana, USA. Combining 13C and 15N natural abundance analyses with mea-surements of microbial residues using amino sugars, the isotope signatures of large, medium and small-sized POM and MAOM fractions were compared with those of leaves, roots and biomass of mycorrhizal and sapro-trophic fungi. A Bayesian inference isotope mixing model calculated sources of C and N to SOM fractions.While the isotope composition of POM resembled that of plants, MAOM was close to fungal values. This was confirmed by mixing model calculations and microbial residue analysis, which additionally and independent from tree partner suggested saprobic fungi contributing with 4-53% to POM and 23-42% to MAOM, as opposed to ECM contributions.Our results suggest fungal, not plant residues, as the source of the most putatively stable OM pool; thus, altering fungal communities may enhance efforts to increase long-term soil C storage.