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林分类型是影响土壤可溶性有机碳、氮库大小的重要因素,但目前对其研究主要集中在表层土壤(0~10 cm).本研究以亚热带地区天然林、毛竹林、格式栲人工林和杉木人工林为对象,用3种不同的浸提方式(冷水、热水和KCl溶液)提取表层(0~10 cm)和深层(40~60 cm)土壤中可溶性有机碳(DOC)和有机氮(DON),研究林分类型对表层和深层土壤可溶性有机碳、氮库的影响.结果表明:林分类型对表层土壤DOC及其占土壤总有机碳(TOC)的比重有显著影响,深层土壤受林分类型的影响不显著;不同林分土壤DON含量仅在表层土壤存在显著差异,在深层土壤差异不显著.林分间土壤微生物生物量碳的差异仅在表层土壤达到显著水平.DON占土壤总氮(TN)的比重在各林分表层和深层土壤间差异均不显著.3种浸提方法得到的DOC和DON库大小顺序为热水>KCl>冷水,不同浸提方法得到的DOC库及DON库的相关性均达到显著水平,表明冷水、热水和KCl溶液浸提得到的有机碳、氮库含有相似组分.冷水和热水浸提方法得到的表层土壤DOC和DON含量及DOC占TOC比重在天然林和毛竹林均显著大于格式栲和杉木人工林,表明天然林和毛竹林土壤可溶性有机碳、氮含量高于格式栲和杉木人工林,更有利于土壤肥力的恢复.
Stand type is an important factor affecting the size of soil dissolved organic carbon and nitrogen pool, but the current research focuses on the surface soil (0 ~ 10 cm) .In this study, natural forest, Phyllostachys praecox, Castanopsis carlesii plantation and Cunninghamia lanceolata plantation was used to extract soluble organic carbon (DOC) and organic nitrogen (NOC) from the surface (0-10 cm) and deep (40-60 cm) soils by three different extraction methods (cold water, hot water and KCl solution) (DON) were used to study the effects of stand types on soil dissolved organic carbon and nitrogen pools in surface soil and deep soil. The results showed that: the stand type significantly affected DOC and its proportion to TOC, The soil DON content in different stands only showed significant difference in topsoil but no significant difference in deep soil.The difference of soil microbial biomass carbon between stands reached significant level only in topsoil.DON There was no significant difference in the total TN (TN) between the topsoil and the deep soil of all stands.The DOC and DON pools obtained by the three extraction methods were in the order of hot water> KCl> cold water, and DOC obtained by different extraction methods Library and DON library are all relevant The results showed that the organic carbon extracted by cold water, hot water and KCl solution contained similar components.The content of DOC and DON in surface soil obtained by cold water and hot water extraction and the proportion of DOC in natural forest and wool The bamboo forest was significantly larger than the Chinese fir and Cunninghamia lanceolata plantations, indicating that soil organic carbon and nitrogen content in natural forest and bamboo forest were higher than those in Chinese fir and Cunninghamia lanceolata plantations, and more conducive to the restoration of soil fertility.