青海不同林分类型土壤养分与微生物功能多样性

摘要

利用常规实验室分析法和 Biolog-Eco微平板法研究青海省不同林型土壤养分与微生物功能多样性。结果表明：大通1#、湟中和尖扎的土壤有机质、全氮和碱解氮含量较高，大通2#、循化和乐都的土壤有机质、全氮和碱解氮含量居中，民和的土壤有机质、全氮和碱解氮含量则较低；土壤全磷含量表现为民和最低，其他林型间差异不显著；土壤速效磷含量表现为循化、尖扎、湟中＞大通1#、大通2#、乐都＞民和；土壤速效钾含量表现为大通2#、民和＞乐都＞大通1#、湟中、循化、尖扎；各林型的土壤全钾含量变化均不显著；不同林型条件对土壤养分的积累总体表现为大通1#、尖扎湟中循化大通2#乐都民和，4种林木对土壤养分的分布和改良表现为云杉白桦山杨落叶松；各林型的土壤微生物群落功能多样性指数表现为乐都、民和＞大通1#、大通2#、湟中＞循化、尖扎；不同林型土壤微生物碳源利用的主成分分析(PCA)显示碳水化合物和氨基酸是微生物利用的主要碳源；各林型土壤养分含量与微生物功能多样性的 RDA分析表明，土壤养分因子很好地解释了微生物功能多样性的变异，对微生物功能多样性有重要的影响，其中有机质、氮素和速效磷是影响土壤微生物代谢的主要因素。%In this study,soil nutrients and microbial community functional diversity of different stand types in Qinghai Province were investigated by conventional laboratory analysis and Biolog-Eco micro plate method. Results showed that Datong 1#,Huangzhong and Jianzha had relative higher content of organic matter,total nitrogen and available nitrogen in the soil,then Datong 2#,Xunhua and Ledu were in intermediate,and Minhe was lower. The total phosphorus content of Minhe was lowest,while there were no significant differences in total phosphorus content between other stand types. The available phosphorus content was Xunhua,Jianzha,Huangzhong > Datong 1 #,Datong 2 #,Ledu > Minhe,and the available potassium content was Datong 2 #,Minhe > Ledu > Datong 1 #,Huangzhong,Xunhua,Jianzha. The total potassium content of each stand type was not significantly different. The accumulation of overall soil nutrients in different stand types was in turn Datong 1#,Jianzha > Huangzhong > Xunhua > Datong 2# > Ledu > Minhe. Effects of four tree species on the distribution and improvement of soil nutrients were in sequence of Picea asperata > Betula platyphylla> Populus davidiana > Larix gmelinii. The soil microbial community functional diversity index in the various stand types was Ledu,Minhe > Datong 1 #,Datong 2 #,Huangzhong,> Xunhua,Jianzha. The principal component analysis of carbon source utilization of the soil microbial community in different stand types showed that carbohydrates and amino acids were the main carbon source. RDA of each stand type soil nutrient content and microbial community functional diversity indicated that soil nutrient factors well explained the variation of the microbial community functional diversity. Soil nutrient had important influence on microbial community functional diversity. The organic matter, nitrogen and available phosphorus were the main factors influencing the metabolism of soil microbial communities.