间伐和修枝对土壤呼吸及微生物群落结构的影响

发布时间：2018-04-04 21:19

  本文选题：杉木人工林　切入点：间伐　出处：《中南林业科技大学》2015年硕士论文

【摘要】：土壤作为陆地生态系统的最大碳库,是森林可持续发展的重要组成部分。土壤呼吸对全球碳平衡和温室效应具有十分重要的意义。土壤微生物群落结构对维持植物正常生长、土壤肥力以及物质能量代谢循环具有决定性作用。杉木是我国亚热带主要造林树种,在我国南方林业生产和生态建设中占有重要地位。研究间伐和修枝对杉木人工林土壤呼吸及微生物群落结构的影响,可为林业生产实践中最大限度发挥人工林固碳能力而制定适宜的经营措施提供理论依据和技术支持。本研究以会同县杉木人工林为研究对象,对土壤呼吸的季节变化规律、土壤呼吸和土壤微生物群落结构对土壤理化性质和环境因素的响应以及间伐和修枝对土壤呼吸和土壤微生物群落结构的影响进行了研究,研究结果表明：(1)杉木人工林土壤呼吸的季节变化整体上呈单峰曲线。不同森林经营措施下土壤呼吸的季节变化规律相似,土壤呼吸速率最大值出现在夏季的7、8、9月,最小值则出现在温度较低的2月。整体上来说,对照(CK)、间伐(T)和修枝(P)三种处理土壤呼吸速率由大到小依次为PTCK,均值分别为1.76μmol·m-2·s-1、1.65μmol·m-2·s-1和1.58μmol·m-2·s-1。(2)温度是土壤呼吸最关键的影响因素。三种处理样地中土壤呼吸与土壤温度均呈极显著正相关(p0.01),土壤温度能解释土壤呼吸变化的90%以上。土壤呼吸与土壤含水量、土壤pH、土壤微生物量碳(MBC)、土壤蔗糖酶、淀粉酶和p-葡萄糖苷酶的相关性均不显著(p0.05)。对照、间伐样地土壤呼吸与细菌、真菌和放线菌的数量均呈负相关,修枝样地土壤呼吸则与其呈正相关。(3)间伐和修枝对土壤温度、土壤含水量和土壤pH无显著影响,间伐和修枝均降低了土壤蔗糖酶和p-葡萄糖苷酶的活性,间伐降低了土壤淀粉酶活性,修枝增加其活性。不同森林经营措施月平均土壤呼吸速率无明显差异,间伐和修枝后土壤呼吸在1、3、4月显著上升,间伐后土壤呼吸在7、9、11月显著下降。(4)土壤微生物数量与土壤温度、土壤pH相关性不显著(p0.05),与土壤含水量、MBC、土壤全C、全N和C/N呈正相关。间伐显著降低了土壤中MBC、全C、全N含量,修枝降低土壤中MBC含量,增加土壤全C、全N含量。间伐和修枝均降低了土壤细菌、真菌、放线菌、革兰氏阳性菌和革兰氏阴性菌的数量以及微生物总数。
[Abstract]:As the largest carbon pool in terrestrial ecosystem, soil is an important part of forest sustainable development.Soil respiration plays an important role in global carbon balance and Greenhouse Effect.The structure of soil microbial community plays a decisive role in maintaining the normal growth of plants, soil fertility and the cycle of substance and energy metabolism.Cunninghamia lanceolata (Cunninghamia lanceolata) is the main afforestation tree in subtropical region of China.The effects of thinning and pruning on soil respiration and microbial community structure of Chinese fir plantation can provide theoretical basis and technical support for making the best use of carbon sequestration ability in forestry production.In this study, Chinese fir plantation in Huitong County was used as the research object, and the seasonal variation of soil respiration was studied.The responses of soil respiration and soil microbial community structure to soil physical and chemical properties and environmental factors, and the effects of thinning and pruning on soil respiration and soil microbial community structure were studied.The results showed that the seasonal variation of soil respiration in Chinese fir plantation showed a single peak curve.The seasonal variation of soil respiration under different forest management measures was similar. The maximum of soil respiration rate appeared in 7 / 8 in summer and the lowest in September and the lowest in February when the temperature was lower.鏁翠綋涓婃潵璇，

本文编号：1711726