武功山草甸不同草种恢复模式土壤呼吸研究

发布时间：2018-07-14 10:40

【摘要】：武功山位于江西省中西部,分布着广袤的山地草甸,拥有较高的经济价值和生态价值。武功山作为国家级风景名胜区每年接待大量来自世界各地的游客和户外爱好者,但过度的旅游开发给武功山山地草甸系统带来了巨大的破坏,大面积草甸退化现象突出。因此,本研究在武功山草甸金顶区域前期研究已经开展不同草种植被修复试验的基础上,选择中华薹草(Carex chinensis)、芒草(Miscanthus sinensis)、飘拂草(Fimbristylis dichotoma)3种修复植被模式和未退化天然芒草植被及退化裸地(无植被)开展土壤呼吸研究,进行为期一年的土壤呼吸原位监测,并同步测定相应的土壤理化指标和植物生物量指标。旨在探讨不同草种修复模式对山地草甸生态系统土壤呼吸的影响规律,剖析修复过程对草甸土壤生态过程以及土壤碳转化过程的影响机制,揭示退化草甸生态系统恢复过程中的作用机理以及土壤功能恢复的生态学机理,为退化山地草甸土壤生态系统恢复的技术和模式选择及开展后续武功山草甸恢复与气候变化响应的研究提供理论依据和参考。主要研究结果如下:(1)不同植被修复模式的土壤呼吸年动态变化呈现出一定相似的规律,土壤呼吸峰值出现在夏季,最小值出现在冬季;峰值最大的是未退化草甸(优势物种芒草),最低的是退化草甸(裸地)。土壤呼吸年CO2累积排放量最大的是未退化草甸和飘拂草修复模式,最低的是裸地;(2)温度与土壤呼吸均具有较高的相关性。裸地、未退化草甸、飘拂草修复模式、芒草修复模式和中华薹草修复模式的Q_(10)值(温度敏感系数)分别为3.11、3.68、2.09、4.10和2.20。温度敏感性大小依次为:芒草修复模式未退化草甸裸地中华薹草修复模式飘拂草修复模式。(3)可溶性碳(DOC)、微生物碳(MBC)含量与土壤呼吸有较高的相关性。(4)采取不同草种进行修复后的草甸植物生物量不同,采用优势种芒草对退化土壤进行修复的植物地上生物量与总生物量最大,其次是飘拂草,中华薹草地上生物量和总生物量最小,飘拂草和芒草地上生物量一致,为298.67g.m-2。综上所述:武功山不同草种修复有利于恢复退化山地草甸生态功能和土壤肥力,修复草种以优势种芒草为佳。温度和DOC对土壤呼吸有显著影响,其中优势种芒草温度敏感性最强,飘拂草最低。
[Abstract]:Wukong Mountain is located in the middle and west of Jiangxi Province, with a wide range of mountain meadows with high economic and ecological value. As a national scenic spot, Wugong Mountain receives a large number of tourists and outdoor enthusiasts from all over the world every year. However, excessive tourism development has caused great damage to the mountain meadow system of Wukong Mountain, and the degradation phenomenon of large area meadow is prominent. Therefore, this study is based on the previous study of the Jinding area of Wukong Mountain Meadow, which has carried out experiments of vegetation restoration of different species of grass. Soil respiration of Carex chinensis), sinensis), (Fimbristylis dichotoma), undegraded natural mango vegetation and degenerated bare land (no vegetation) were studied in situ monitoring of soil respiration for one year. The soil physicochemical index and plant biomass index were measured simultaneously. The purpose of this study was to investigate the effects of different remediation models on soil respiration in mountain meadow ecosystem, and to analyze the mechanism of the effects of remediation on soil ecological processes and soil carbon transformation in meadow. The ecological mechanism of the restoration of degraded meadow ecosystem and the restoration of soil function were revealed. It provides a theoretical basis and reference for the selection of techniques and models for soil ecosystem restoration in degraded mountain meadow and for the subsequent study on the restoration of meadow and the response to climate change in Wugong Mountain. The main results are as follows: (1) the dynamic changes of soil respiration in different vegetation restoration models showed a similar pattern, the peak value of soil respiration appeared in summer, and the minimum occurred in winter; The highest peak was in undegraded meadow (dominant species mango) and the lowest in degraded meadow (bare land). The annual CO2 accumulative emissions of soil respiration were the largest in undegraded meadow and floating grass remediation model, and the lowest in bare land. (2) there was a high correlation between temperature and soil respiration. The Q _ (10) values (temperature sensitivity coefficient) of bare land, undegraded meadow, repairment model, mango repair model and Carex sinensis repair model were 3.113.682.09 (4.10) and 2.20 (r = 2.20), respectively. The order of temperature sensitivity was: Carex sinensis repair model in undegraded meadow, (3) soluble carbon (DOC), microbial carbon (MBC) content and soil respiration. The plant biomass of meadow was different after restoration. The aboveground biomass and the total biomass of the degraded soil were the largest, followed by the fluffy grass, the minimum biomass and the total biomass on the Chinese bolting grassland, and the biomass on the Avening grassland was the same (298.67 g 路m ~ (-2). To sum up: the restoration of different grass species in Wugong Mountain is beneficial to the restoration of ecological function and soil fertility of degraded mountain meadow, and the dominant species is the best. Temperature and DOC had significant effects on soil respiration, among which the dominant species was the most sensitive to temperature and the lowest.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812.2

【参考文献】