辽西油松侧柏混交林对土壤微生物群落功能多样性的影响

Effects of Mixed Pinus tabulaeformis and Platycladus orientalis plantation on the Function Diversity of Soil Microbial Community in Western Part of Liaoning Province

为探讨油松(Pinus tabulaeformis)、侧柏(Platycladus orientalis)混交林造林模式对土壤微生物群落功能多样性的影响,以朝阳市建平县白山林场试验区油松纯林(YC)、无植物种植土壤(NP)和油松-侧柏二者的混交林(YB)为研究对象,运用Biolog-Eco技术,对不同造林模式土壤微生物代谢功能多样性进行研究,对不同造林模式土壤微生物群落功能多样性进行分析。结果表明:不同造林模式土壤微生物群落代谢活性差异显著,总碳源的利用能力(AWCD)的顺序为:YB>YC>NP,油松、侧柏混交林土壤微生物代谢最快,活性最强。3种造林模式土壤微生物对6大碳源的利用率存在差异,混交林土壤微生物对L-天门冬酰胺、L-苯基丙氨酸、吐温40、吐温80、i-赤藓糖醇、D-甘露醇和4-羟基苯甲酸7种碳源的利用代谢能力显著高于油松纯林(p<0.05)。Biolog代谢指纹图谱分析表明混交林土壤微生物对吐温80的利用能力最高,AWCD值为1.6537;油松纯林土壤微生物对L-精氨酸的利用能力最高,AWCD值为1.547。主成分分析显示,YB和YC土壤微生物群落具有相似的碳源利用模式,土壤微生物群落代谢功能相似。3种造林模式土壤微生物Shannon指数(H)和Simpson指数(D)无明显差异,物种Mclntosh指数(U)依次为YB>YC>NP。油松和侧柏混交后可以提高土壤微生物活性。由此可见,在辽西半干旱区营造油松-侧柏混交林是可行的。

In order to evaluate the effect of the mixed forest（Pinus tabulaeformis ＋Platycladus orientalis） on soil microbial community functional diversity, by using Biology Ecoplate system, we studied the functional diversity of soil microbial community in three different vegetation types, including pure coniferous forest（Pinus tabulaeformis）（YC）, basal soil（NP）, and mixed forest（P.tabulaeformis＋Platycladus orientalis）（YB） in the arid areas afforestation area, in Jianping county, in Chaoyang, aimed to probe into the effects of vegetation types on the diversity of soil microbial community. The results showed that, total carbon source utilization capacity（AWCD） by soil microbial communities was in the order of YB〉 YC〉 NP, indicating that soil microbial metabolic activity in YB was the highest. There were differences in microbial utilization rate of six major carbon sources among the three forests. The mixed forest had significantly higher microbial utilization rates in L-asparagine, L-phenylalanine, twain 40,twain 80, i-erythritol, D-mannitol and 4-hydroxybenzoic acid（seven kinds of carbon source） compared with the YC（p〈0.05）.Metabolic fingerprint of carbon physiological profiles of microbial community showed that the mixed forest and coniferous forest had significantly highest microbial utilization rates in twain 80 and L-arginine. Principal component analysis showed that soil microbial communities of YB and YC had similar carbon source utilization patterns. There was no significant difference in Shanon＇s diversity index and Simpson＇s index of soil microbes among the three types. The Mclntosh＇s index was in the order of YB 〉YC〉 NP. Our results demonstrated that planting P. tabulaeformis and Platycladus orientalis trees together can improve soil microbial activity. Thus it can be seen that it is feasible to plant P. tabulaeformis and Platycladus orientalis trees together in western part of Liaoning province.