论文部分内容阅读
混交林可以形成层次多或冠层厚的林分结构,对提高防护效能和稳定性具有重要作用。本研究先对20年林龄的马尾松(Pinus massoniana)人工林进行5种不同强度的采伐(皆伐、强度、中强度、中弱度和弱度,伐后郁闭度分别为0、0.4、0.5、0.6和0.7),然后在林下等量种植肉桂(Cinnamomum cassia)。7年后,应用BIOLOG-ECO技术探讨不同混交模式、林分类型对土壤微生物功能多样性的影响。结果表明,混交林的土壤理化性质、AWCD(average well color development)值和微生物功能多样性指数均优于马尾松和肉桂纯林,其中肉桂纯林最低、基于中弱度采伐而建的混交林最高(与马尾松纯林差异显著),且土壤微生物功能多样性随土层深度增加而降低。主成分分析结果显示,不同混交模式之间土壤微生物碳源利用特征分异不明显;而不同林分类型之间存在明显分异,主要起分异作用的是微生物对氨基酸类、羧酸类和糖类的利用特征,且不同林分类型对土壤微生物碳源利用的差异显著受土壤含水率与有机质含量影响;含水率、有机质、全氮、全磷、全钾含量和土壤碳氮比对土壤微生物群落功能多样性也有着重要影响。可见,马尾松林种植肉桂能提高微生物活性和功能多样性,本研究结果可为改造马尾松纯林为混交林提供参考。
Mixed forest can form multi-level or canopy thick forest structure, to improve the effectiveness and stability of the protective effect. In this study, five different intensities of harvesting (Pinus massoniana plantation, 20 years old) were harvested (clear cutting, strength, medium strength, moderate and weakness, weakness and post- 0.5, 0.6 and 0.7), and then planting Cinnamomum cassia in the same amount under the forest. Seven years later, the BIOLOG-ECO technique was used to investigate the effects of different mixed patterns and stand types on functional diversity of soil microorganisms. The results showed that the soil physical and chemical properties, average well color development (AWCD) and microbial functional diversity index (AWCD) of mixed forest were better than that of pure stands of Pinus massoniana and Cinnamomum cassia, of which pure pure cinnamon was the lowest, mixed forest The highest (with significant difference from Pinus massoniana pure forest), and the functional diversity of soil microorganism decreased with the increase of soil depth. The results of principal component analysis showed that there was no significant difference in the utilization characteristics of soil microbial carbon sources among different mixed patterns. However, there were obvious differences among different forest types. The major differences were microbial responses to amino acids, carboxylic acids and Carbohydrate utilization characteristics of different types of soil microbial carbon sources significantly affected by soil moisture and organic matter content; water content, organic matter, total nitrogen, total phosphorus, total potassium and soil carbon to nitrogen ratio of soil Microbial community diversity also has a significant impact. It can be seen that planting cinnamon in masson pine forest can improve microbial activity and functional diversity. The results of this study can provide reference for the improvement of Pinus massoniana pure forest for mixed forest.