不同林龄杉木人工林土壤易变性碳、氮含量的变化  

Changes of Soil Labile Carbon and Nitrogen Contents in Cunninghamia Lanceolata Plantations with Different Stand Ages

作　　者：张冰冰 万晓华[1] ZHANG Bing-bing;WAN Xiao-hua(Fujian Normal University,Fuzhou,Fujian 350007,China)

机构地区：[1]福建师范大学

出　　处：《福建农业科技》2020年第1期33-39,共7页Fujian Agricultural Science and Technology

基　　金：福建省自然科学基金面上项目(2018J01714);福建省教育厅项目(JAT160113)

摘　　要：土壤微生物生物量虽然仅占土壤有机碳的5%,但在有机质分解与养分循环过程中扮演重要角色。采用空间替换时间的方法在我国亚热带地区选取杉木人工林5年、8年、21年、27年和40年等5个不同林龄,测定了土壤可溶性有机碳、可溶性有机氮含量以及土壤微生物生物量碳、土壤微生物生物量氮含量,探究不同林龄杉木人工林土壤易变性碳、氮组分的变化特征。结果表明:不同林龄杉木人工林中,5年生林分土壤铵态氮含量显著高于8年生和40年生林分。27年生和40年生林分土壤可溶性有机碳(DOC)含量显著高于5年生和21年生林分。5年生杉木的微生物生物量碳(MBC)含量显著低于其他林龄,21年生林分土壤微生物生物量氮(MBN)含量最低。土壤硝态氮和全碳与土壤可溶性有机碳、可溶性有机氮具有相关性,土壤微生物生物量碳与土壤全碳、全氮之间关系密切。研究结果表明,不同林龄杉木人工林土壤微生物碳氮库的大小可能与土壤养分有关。Although soil microbial biomass only accounts for 5%of soil organic carbon,it plays an important role in the process of organic matter decomposition and nutrient cycling.By using the temporal-spatial substitution method,five different stand ages of Cunninghamia lanceolata plantation,such as 5-year-old,8-year-old,21-year-old,27-year-old and 40-year-old were selected in the subtropical region of China.The content of soil dissolve organic carbon and dissolve organic nitrogen and the content of soil microbial biomass carbon and nitrogen were determined to explore the changing characteristics of soil labile carbon and nitrogen components in Cunninghamia lanceolata plantation at different stand ages.The results showed that the content of soil ammonium nitrogen in the 5-year-old stands was significantly higher than that in the 8-year-old stands and 40-year-old stands in Cunninghamia lanceolata plantations of different ages.The contents of dissolve organic carbon(DOC)in the 27-year-old and 40-year-old stands were significantly higher than that in the 5-year-old and 21-year-old stands.The microbial biomass carbon(MBC)content of the 5-year-old Cunninghamia lanceolata was significantly lower than that of other stand ages,and the microbial biomass nitrogen(MBN)content of the 21-year-old Cunninghamia lanceolata was the lowest.The soil nitrate nitrogen and total carbon were correlated with soil dissolve organic carbon and nitrogen,and the soil microbial biomass carbon was closely related to soil total carbon and total nitrogen.The results indicated that the size of soil microbial carbon and nitrogen pools in Cunninghamia lanceolata plantation at different stand ages may be related to soil nutrients.

关 键 词：杉木 林龄 可溶性有机碳 土壤微生物生物量碳 土壤微生物生物量氮 

分 类 号：S718.5[农业科学—林学]