红壤区退化林地表土真菌群落结构对土壤改良措施的响应

真菌群落结构和多样性对于土壤改良效果具有高敏感性.研究南方红壤区侵蚀退化林表土真菌群落对有机肥、生物炭和石灰+微生物肥的响应，以明晰不同改土措施的作用.结果表明：(1)3种土壤改良措施均降低了表土真菌丰富度，其中石灰+微生物肥降低作用最大，3种土壤改良措施对表土真菌多样性也有影响，但影响不显著；(2)表土中优势真菌门为子囊菌门(Ascomycota, 31.29%～46.55%)、担子菌门(Basidiomycota, 30.07%～70.71%),优势真菌属为阿太菌属(Amphinema)和单形古根菌属(Archaeorhizomyces),3种土壤改良措施对表土真菌群落结构的影响不同，有机肥提高了子囊菌门和单形古根菌属的相对丰度，生物炭提高了担子菌门和阿太菌属的相对丰度，而石灰+微生物肥则提高了担子菌门和单形古根菌属的相对丰度；(3)土壤pH是影响表土真菌丰富度的关键因子，而表土真菌群落结构则受pH、全氮和有机碳的影响.研究结果为南方红壤区侵蚀退化林地土壤改良，林下植被生态恢复提供科学指导.

Response of Topsoil Fungal Community Structure to Soil Improvement Measures in Degraded Forest of Red Soil Region

Soil fungal community structure and diversity are highly sensitive to variations in the external environment, as well as soil improvement measures. In order to clarify the effects of soil improvement measures on topsoil fertility or quality, a field experiment was conducted in eroded forest of a red soil region. Organic fertilizer, biochar, and lime+microbial fertilizer were added to the topsoil, respectively. After four years, the chemistry properties and nutrients in the topsoil were measured, and the diversity and composition of fungi were analyzed. The results showed that the additions of organic fertilizer, biochar, and lime+microbial fertilizer reduced fungal richness in topsoil, compared to that with no fertilizer addition (CK). Among them, lime+microbial fertilizer had the most negative effect on fungal richness. The three soil improvement measures also affected the diversity of topsoil fungi, but the impacts were not significant. The dominant fungal phyla in the topsoil were Ascomycota (31.29%-46.55%) and Basidiomycota (30.07%-70.71%), and the dominant fungal genera were Amphinema and Archaeorhizomyces. The effects of soil improvement measures on fungal community structure in the topsoil were different; organic fertilizer increased the relative abundance of Ascomycetes and Archaeopteroides, and biochar enhanced the relative abundance of Basidiomycetes and Archaeopteroides, whereas lime+microbial fertilizer improved the relative abundance of Basidiomycetes and Archaeopteroides. Fungal diversity and community structure in the topsoil was affected by edaphic factors, and fungal richness was regulated by pH value, whereas fungal community structure was influenced by pH, total nitrogen, and organic carbon. This study provides scientific guidance for soil improvement and ecological restoration below the canopy in eroded forests of red soil regions.