Cheng Zhichao, Wu Song, Pan Hong, Lu Xinming, Liu Yongzhi, Yang Libin
Key Laboratory of Biodiversity, Institute of Natural Resources and Ecology, Heilongjiang Academy of Sciences, Harbin 150040, China.
Heilongjiang Huzhong National Nature Reserve, Daxing'anling 165038, China.
J Fungi (Basel). 2023 Nov 17;9(11):1113. doi: 10.3390/jof9111113.
Fungi have important ecological functions in the soil of forests, where they decompose organic matter, provide plants with nutrients, increase plant water uptake, and improve plant resistance to adversity, disease, and disturbance. A forest fire presents a serious disturbance of the local ecosystem and can be considered an important component affecting the function of ecosystem biomes; however, the response of soil fungi to fire disturbance is largely unknown. To investigate the effects of fire disturbance on the community composition and diversity of soil fungi in a taiga forest, we collected soil from plots that had undergone a light, moderate, and heavy fire 10 years previously, with the inclusion of a fire-free control. The present soil fungi were characterized using Illumina MiSeq technology, and the sequences were analyzed to identify differences in the community composition and diversity in response to the changed soil physicochemical properties. The results showed that the Chao1 index, which characterizes the alpha diversity of the fungi, did not change significantly. In contrast, the Shannon index increased significantly ( < 0.05) and the Simpson index decreased significantly ( < 0.05) following a light or heavy fire disturbance compared to the control. The relative abundance of Basidiomycota was significantly higher in the soil of the fire sites than that in the control ( < 0.01), and the relative abundance of Ascomycota was significantly lower ( < 0.01). The results of principal coordinates analyses (PCoAs) showed that fire disturbance highly significantly affected the beta diversity of soil fungi ( < 0.001), while the results of canonical correlation analysis (CCA) indicated that the available nitrogen (AN), moisture content (MC), pH, available potassium (AK), and total nitrogen (TN) contents of the soil significantly affected the compositional structure and diversity of the soil fungal communities. The results of functional prediction showed that the majority of the detected soil fungi were symbiotrophs, followed by saprotrophs and saprotroph-symbiotrophs, with ectomycorrhiza being the dominant functional taxon. Fire disturbance significantly reduced the relative abundance of ectomycorrhiza ( < 0.05). This study illustrates that fire disturbance alters the structural composition, diversity, dominance, and relative abundance of the guilds of soil fungal communities in taiga forest, and strongly affected the beta diversity of soil fungi, with AN, MC, pH, AK, and TN being the most important factors affecting their community structure. The results may provide a useful reference for the restoration and rehabilitation of taiga forests after fire disturbance.
真菌在森林土壤中具有重要的生态功能，它们分解有机物，为植物提供养分，增加植物对水分的吸收，并提高植物对逆境、疾病和干扰的抵抗力。森林火灾对当地生态系统造成严重干扰，可被视为影响生态系统生物群落功能的一个重要因素；然而，土壤真菌对火灾干扰的响应在很大程度上尚不清楚。为了研究火灾干扰对泰加林土壤真菌群落组成和多样性的影响，我们从10年前经历过轻度、中度和重度火灾的样地采集土壤，并设置了无火灾对照样地。利用Illumina MiSeq技术对当前土壤真菌进行表征，并对序列进行分析，以确定土壤理化性质变化后群落组成和多样性的差异。结果表明，表征真菌α多样性的Chao1指数没有显著变化。相比之下，与对照相比，轻度或重度火灾干扰后，香农指数显著增加（<0.05），辛普森指数显著降低（<0.05）。担子菌门在火灾样地土壤中的相对丰度显著高于对照（<0.01），而子囊菌门的相对丰度显著低于对照（<0.01）。主坐标分析（PCoA）结果表明，火灾干扰对土壤真菌的β多样性有极显著影响（<0.001），而典范对应分析（CCA）结果表明，土壤中的有效氮（AN）、含水量（MC）、pH值、有效钾（AK）和全氮（TN）含量显著影响土壤真菌群落的组成结构和多样性。功能预测结果表明，检测到的大多数土壤真菌为共生营养型，其次是腐生营养型和腐生-共生营养型，外生菌根是主要的功能类群。火灾干扰显著降低了外生菌根的相对丰度（<0.05）。本研究表明，火灾干扰改变了泰加林土壤真菌群落的结构组成、多样性、优势度和功能类群的相对丰度，并强烈影响了土壤真菌的β多样性，其中AN、MC、pH值、AK和TN是影响其群落结构的最重要因素。研究结果可为火灾干扰后泰加林的恢复和重建提供有益参考。
