环割对杉木和马尾松人工林土壤微生物群落结构的影响

发布时间：2018-07-09 11:09

本文选题：杉木 + 马尾松　；参考：《林业科学》2017年06期

【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%(P0.01),硝态氮增加了182.1%(P0.01),有效磷和土壤含水量分别增加了66.9%和10.6%(P0.05);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%(P0.05),土壤含水量增加了12.1%(P0.01)。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%(P0.05),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%(P0.05);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%(P0.05);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%(P0.05);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(P0.05),而马尾松林中该比值的升高则发生在环割1年后(P0.05),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(P0.01),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(P0.05),土壤有效磷含量与革兰氏阳性细菌含量显著正相关(P0.05),土壤NH+4-N含量与总磷脂脂肪酸、细菌、革兰氏阳性细菌和革兰氏阴性细菌含量极显著负相关(P0.01),与真菌含量显著负相关(P0.05),土壤p H值与总磷脂脂肪酸、细菌、真菌和革兰氏阳性细菌含量极显著正相关(P0.01),与革兰氏阴性细菌含量显著正相关(P0.05),土壤有机碳含量与总磷脂脂肪酸、细菌、真菌和革兰氏阳性细菌含量显著正相关(P0.05),全磷含量与总磷脂脂肪酸、真菌和革兰氏阴性细菌含量显著正相关(P0.05),与细菌和革兰氏阳性细菌含量极显著正相关(P0.01),土壤含水量与土壤微生物生物量没有显著相关性(P0.05)。【结论】环割导致植物光合产物供应变化,进而改变了土壤碳的可利用性及养分有效性,降低了土壤微生物生物量,改变了微生物群落结构,且对真菌群落的影响要高于细菌群落,而且环割对微生物的影响具有树种差异性。
[Abstract]:[objective] to reveal the effect of ring cutting on the structure of soil microbial community in forest. [methods] in June 2012, 6 6 m 脳 6 m plots were arranged in Chinese fir and Masson pine plantations, each sample containing at least 5 trees. The average height and DBH of Chinese fir and Masson pine were 16.3 and 15.3 m, and the average DBH were 18.5 and 17.2 cm, respectively. Each stand was randomly selected for ring cutting, that is, the bark and phloem of 10 cm wide were removed at the DBH of the tree to block the underground carbon distribution of photosynthetic products, and the other 3 were used as control. The basic physical and chemical properties of soil were determined after 1 month of cyclization. The microbial community structure of soil was determined by phospholipid fatty acid method after 1 month and 1 year of cyclization. [results] the content of soluble organic carbon in soil decreased by 18.3% (P0.01), nitrate nitrogen increased by 182.1% (P0.01), available phosphorus and soil were increased by 182.1% (P0.01), and available phosphorus and soil were increased by 182.1% (P0.01). The water content increased by 66.9% and 10.6% (P0.05) respectively. The contents of nitrate nitrogen and available phosphorus increased by 11.3% and 235.5% (P0.05) respectively, and the soil moisture increased by 12.1% (P0.01). Ring cutting reduces soil microbial biomass and changes the structure of microbial community, and this effect is different in species and time. The total phospholipid fatty acids, bacteria, fungi in Chinese fir forest were cut for 1 month. Fungi: the contents of bacteria and Gram-negative bacteria decreased by 10.3% and 10.9% respectively (P0.05), the contents of bacteria and Gram-negative bacteria decreased by 20.3% and 13.4% (P0.05) respectively, and the contents of bacteria and Gram-negative bacteria decreased by 20.3% and 22.1% (P0.05) after 1 year's circumcision, respectively, and those of fungi and Gram-positive bacteria in Pinus massoniana forest were decreased by 1 month. The contents of total phospholipid fatty acids decreased by 21.9% and 14.5% (P0.05), respectively. The contents of bacteria and actinomycetes decreased by 17.8% and 27.4% respectively (P0.05), the phospholipid fatty acid (cy17:0/16:1 蠅 7c) in soil of Chinese fir forest increased significantly (P0.05) after 1 month of cyclic cutting, while the increase of this ratio occurred after 1 year of ring cutting (P0.05) in Pinus massoniana forest. The high availability of available carbon results in microbial growth pressure. Correlation analysis showed that soil soluble organic carbon content and total phospholipid fatty acids, bacteria, fungi, Significant positive correlation was found between Gram-positive bacteria and Gram-negative bacteria (P0.01). Soil NO-3-N and total nitrogen contents were significantly positively correlated with bacteria and Gram-positive bacteria (P0.05). Soil available phosphorus content was significantly correlated with Gram-positive bacteria (P0.01). The content of NH _ 4-N in soil and total phospholipid fatty acids were positively correlated (P0.05). The contents of bacteria, Gram-positive bacteria and Gram-negative bacteria were significantly negative correlation (P0.01), significant negative correlation with fungal content (P0.05), soil pH and total phospholipid fatty acids, bacteria, The content of fungi and Gram-positive bacteria was significantly positive correlation (P0.01), and the content of Gram-negative bacteria was significantly positive correlation (P0.05), soil organic carbon content and total phospholipid fatty acids, bacteria, There was a significant positive correlation between fungi and Gram-positive bacteria (P0.05), total phosphorus content and total phospholipid fatty acids, There was a significant positive correlation between fungi and Gram-negative bacteria (P0.05), a very significant positive correlation with bacteria and Gram-positive bacteria (P0.01), and no significant correlation between soil moisture content and soil microbial biomass (P0.05). Changes in the supply of photosynthetic products, Furthermore, soil carbon availability and nutrient availability were changed, soil microbial biomass was reduced, microbial community structure was changed, and the effect on fungal community was higher than that on bacterial community. Moreover, the effect of ring cutting on microorganism is different in tree species.
【作者单位】：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;中国科学院会同森林生态实验站;
【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)
【分类号】：S714.3

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