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以撂荒地为对照,油松人工幼龄林(13~15 a)、中龄林(25~27 a)和成熟林(41~43a)为研究对象,分析了黄土高原典型油松人工林不同生长阶段土壤微生物生物量碳的变化特征及其影响因素.结果表明:油松幼龄林、中龄林和成熟林土壤微生物生物量碳分别为93.08、122.64和191.34 mg·kg~(-1),随发育阶段呈显著增加趋势,且显著高于撂荒地(42.93mg·kg~(-1)).土壤微生物生物量碳随土层深度呈逐渐降低的趋势,在0~20 cm土层油松幼龄林、中龄林和成熟林较撂荒地分别提高了134.2%、221.7%和375.7%,在20~40 cm土层分别提高了101.3%、164.3%和337.5%,在40~60 cm土层分别提高了103.1%、146.2%和303.0%.油松胸径、高度、根系生物量以及枯落物的厚度、生物量、全氮含量与土壤微生物生物量碳呈显著正相关;土壤有机碳、全氮含量及土壤含水量与土壤微生物生物量碳呈显著正相关.主成分分析表明,油松根系生物量、枯落物生物量和土壤有机碳含量是影响黄土高原油松人工林微生物特征的主要因子.油松生长过程中,枯落物和根系凋落物显著影响了土壤有机碳含量,提高了土壤微生物生物量碳.
The artificial forest of Pinus tabulaeformis (13 ~ 15 a), middle-aged forest (25 ~ 27 a) and mature forest (41 ~ 43 a) The results showed that the soil microbial biomass carbon was 93.08, 122.64 and 191.34 mg · kg -1 in the young, middle-aged and mature stands, respectively. , Which increased significantly with the developmental stages and was significantly higher than that of the fallow land (42.93 mg · kg -1). The soil microbial biomass carbon decreased gradually with soil depth, The young, middle-aged and mature forests increased by 134.2%, 221.7% and 375.7% in the mature and young stands, respectively, increased by 101.3%, 164.3% and 337.5% in the 20-40 cm soil layer and 40-60 cm Soil layer increased by 103.1%, 146.2% and 303.0%, respectively.The DBH, height, root biomass, litter thickness, biomass and total N of soil had a significant positive correlation with soil microbial biomass carbon, , Total nitrogen content and soil water content had significant positive correlation with soil microbial biomass carbon.Primary component analysis showed that Pinus tabulaeformis root system , Litter biomass and soil organic carbon content were the main factors that affected the microbial characteristics of Pinus tabulaeformis plantation.Litter and root litter significantly affected soil organic carbon content during the growth of Pinus tabulaeformis and increased soil microbial Biomass carbon.