Kimeklis Anastasiia K, Gladkov Grigory V, Zverev Aleksei O, Kichko Arina A, Andronov Evgeny E, Ergina Elena I, Kostenko Igor V, Abakumov Evgeny V
Applied Ecology, St. Petersburg State University, Saint-Petersburg, Russia.
Laboratory of Microbiological Monitoring and Bioremediation of Soils, All-Russian Research Institute for Agricultural Microbiology, Pushkin, Russia.
PeerJ. 2021 Feb 18;9:e10871. doi: 10.7717/peerj.10871. eCollection 2021.
Rendzic Leptosols are intrazonal soils formed on limestone bedrock. The specialty of these soils is that parent rock material is more influential in shaping soil characteristics than zonal factors such as climate, especially during soil formation. Unlike fast evolving Podzols due to their leaching regime, Leptosols do not undergo rapid development due to the nature of the limestone. Little is known how microbiome reflects this process, so we assessed microbiome composition of Rendzic Leptosols of different ages, arising from disruption and subsequent reclamation. The mountains and foothills that cover much of the Crimean Peninsula are ideal for this type of study, as the soils were formed on limestone and have been subjected to anthropogenic impacts through much of human history. Microbiomes of four soil sites forming a chronosequence, including different soil horizons, were studied using sequencing of 16S rRNA gene libraries and quantitative PCR. Dominant phyla for all soil sites were Actinobacteria, Proteobacteria, Acidobacteria, Bacteroidetes, Thaumarchaeota, Planctomycetes, Verrucomicrobia and Firmicutes. Alpha diversity was similar across sites and tended to be higher in topsoil. Beta diversity showed that microbiomes diverged according to the soil site and the soil horizon. The oldest and the youngest soils had the most similar microbiomes, which could have been caused by their geographic proximity. Oligotrophic bacteria from Chitinophagaceae, Blastocatellaceae and Rubrobacteriaceae dominated the microbiome of these soils. The microbiome of 700-year old soil was the most diverse. This soil was from the only study location with topsoil formed by plant litter, which provided additional nutrients and could have been the driving force of this differentiation. Consistent with this assumption, this soil was abundant in copiotrophic bacteria from Proteobacteria and Actinobacteria phyla. The microbiome of 50-year old Leptosol was more similar to the microbiome of benchmark soil than the microbiome of 700-year old soil, especially by weighted metrics. CCA analysis, in combination with PERMANOVA, linked differences in microbiomes to the joint change of all soil chemical parameters between soil horizons. Local factors, such as parent material and plant litter, more strongly influenced the microbiome composition in Rendzic Leptosols than soil age.
黑色石灰土是在石灰岩基岩上形成的隐域土。这些土壤的特殊之处在于，与气候等地带性因素相比，母岩物质在塑造土壤特性方面的影响更大，尤其是在土壤形成过程中。与因淋溶作用而快速演化的灰化土不同，由于石灰岩的性质，黑色石灰土不会经历快速发育。关于微生物群落如何反映这一过程知之甚少，因此我们评估了因干扰和随后开垦而形成的不同年龄的黑色石灰土的微生物群落组成。覆盖克里米亚半岛大部分地区的山脉和山麓非常适合此类研究，因为这些土壤是在石灰岩上形成的，并且在人类历史的大部分时间里都受到了人为影响。我们使用16S rRNA基因文库测序和定量PCR研究了形成时间序列的四个土壤地点的微生物群落，包括不同的土壤层。所有土壤地点的优势菌门为放线菌门、变形菌门、酸杆菌门、拟杆菌门、奇古菌门、浮霉菌门、疣微菌门和厚壁菌门。各地点的α多样性相似，且表土中的α多样性往往更高。β多样性表明，微生物群落根据土壤地点和土壤层而有所不同。最古老和最年轻的土壤具有最相似的微生物群落，这可能是由于它们地理位置相近。来自噬几丁质菌科、芽单胞菌科和红杆菌科的贫营养细菌在这些土壤的微生物群落中占主导地位。700年历史土壤的微生物群落最为多样。这种土壤来自唯一一处表土由植物凋落物形成的研究地点，植物凋落物提供了额外的养分，可能是这种分化的驱动力。与此假设一致，这种土壤中来自变形菌门和放线菌门的富营养细菌含量丰富。50年历史的黑色石灰土的微生物群落比700年历史土壤的微生物群落更类似于基准土壤的微生物群落，尤其是通过加权指标衡量时。典范对应分析（CCA）与多变量方差分析（PERMANOVA）相结合，将微生物群落的差异与土壤层之间所有土壤化学参数的联合变化联系起来。在黑色石灰土中，母质和植物凋落物等局部因素对微生物群落组成的影响比土壤年龄更大。
