环割对杉木和马尾松人工林土壤微生物群落结构的影响  

Effects of Girdling on Soil Microbial Community Composition in Cunninghamia lanceolata and Pinus massoniana Plantations

作　　者：贺同鑫 孙建飞[1] 李艳鹏[2] 俞有志 胡宝清[1] 王清奎[2] 

机构地区：[1]广西师范学院北部湾环境演变与资源利用教育部重点实验室广西地表过程与智能模拟重点实验室,南宁530001 [2]中国科学院会同森林生态实验站,会同418307

出　　处：《林业科学》2017年第6期77-84,共8页Scientia Silvae Sinicae

基　　金：中国科学院战略性先导科技专项(XDB15010301);国家自然科学基金项目(31570466);国家重点研发计划(2016YFA0600801);广西科学研究与技术开发计划(14125008-2-24)

摘　　要：【目的】以期揭示环割对森林土壤微生物群落结构的影响。【方法】2012年6月在杉木和马尾松人工林中分别布置6个6 m×6 m样方,每个样方至少包含5棵树。杉木和马尾松平均树高分别为16.3和15.3 m,平均胸径分别为18.5和17.2 cm。每种林分随机选择3个样方进行环割,即在树木胸径处去除10 cm宽的树皮和韧皮部,以阻断光合产物的地下碳分配,剩余3个为对照。环割1个月后测定土壤基本理化性质,环割1个月和1年后采用磷脂脂肪酸方法测定土壤微生物群落结构。【结果】杉木林环割1个月后土壤可溶性有机碳含量降低了18.3%(P<0.01),硝态氮增加了182.1%(P<0.01),有效磷和土壤含水量分别增加了66.9%和10.6%(P<0.05);马尾松林环割1个月后土壤可溶性有机碳、硝态氮和有效磷含量分别增加了11.3%,72.7%和235.5%(P<0.05),土壤含水量增加了12.1%(P<0.01)。环割降低了土壤微生物生物量并改变了微生物群落结构,而且这种影响存在树种和时间差异性。杉木林环割1个月后总磷脂脂肪酸、细菌、真菌、真菌∶细菌和革兰氏阴性细菌含量分别降低了10.3%,10.9%,20.0%,10.1%和13.4%(P<0.05),环割1年后细菌和革兰氏阴性细菌的含量分别降低了20.3%和22.1%(P<0.05);马尾松林环割1个月后真菌和革兰氏阳性细菌的含量分别降低了21.9%和14.5%(P<0.05);环割1年后总磷脂脂肪酸、细菌和放线菌含量分别降低了17.8%,15.9%和27.4%(P<0.05);环割1个月后杉木林土壤中磷脂脂肪酸cy17∶0/16∶1ω7c显著升高(P<0.05),而马尾松林中该比值的升高则发生在环割1年后(P<0.05),该比值的升高表明可利用碳有效性不足引起了微生物生长压力。相关分析表明土壤可溶性有机碳含量与总磷脂脂肪酸、细菌、真菌、革兰氏阳性细菌和革兰氏阴性细菌含量极显著正相关(P<0.01),土壤NO-3-N和全氮含量均与细菌和革兰氏阳性细菌含量显著正相关(P<0.05),土壤有效磷含�【Objective】This study was carried out to reveal the effect of girdling on forest soil microbial communitycomposition.【Method】Six plots（ 6 m × 6 m） were established in Cunninghamia lanceolata and Pinus massoniana stands respectively in June 2012,and each plot contained at least 5 trees. The mean heights of C. lanceolata and P.massoniana were 16. 3 and 15. 3 m respectively,and the mean diameters at breast height were 18. 5 and 17. 2 cm respectively. Three plots were randomly selected as girdling treatment,and trees were girdled by removing 10 cm of bark and phloem over the entire circumference of the stem at breast height, and the others as control treatment. Soil physicochemical properties were measured after one month of girdling,and microbial community composition was measured by phospholipid fatty acid after one month and one year of girdling respectively.【Result】The content of dissolved organic carbon was decreased by 18. 3%（ P〈0. 01）,and the content of NO-3-N was increased by 182. 1%（ P〈0. 01）,and available phosphorus content and soil water content were increased by 66. 9% and 10. 6% respectively（ P〈0. 05） after one month of girdling in the C. lanceolata plantation. In the P. massoniana plantation,the contents of dissolved organic carbon,NO-3-N and available phosphorus were increased by 11. 3%,72. 7% and 235. 5% respectively（ P〈0. 05）,and soil water content was increased by 12. 1%（ P〈0. 01） after one month of girdling. Girdling decreased soil microbial biomass and altered the microbial community composition in both plantations,while the effects of girdling on soil microbes were different between the two tree species at different sampling time. In the C. lanceolata plantation,the contents of total PLFAs,bacteria,fungi,the ratio of fungi to bacteria and Gram-negative bacteria were significantly decreased by 10. 3%,10. 9%,20. 0%,10. 1%,and 13. 4% respectively（ P〈0. 05） after one month of girdling,and girdling decreased the contents of bacteria and Gram-negativ

关 键 词：杉木 马尾松 人工林 磷脂脂肪酸 环割 微生物群落结构 

分 类 号：S714.3[农业科学—林学]