典型麻竹林土壤植硅体碳的空间异质性特征

发布时间：2019-03-14 20:20

【摘要】：由于植硅体具有超强的耐高温、抗氧化及抗分解等的特性,使得植硅体碳可以在植硅体这层坚硬外壳的保护下存于土壤以及沉积物中高达上万年之久。因此,植硅体碳是土壤稳定性碳库的重要来源之一,对于增强土壤碳汇,维持全球CO2平衡具有重要意义。森林是地球陆地生态系统的主体,而在全球森林面积急剧下降的今天,竹林面积却仍在增加,因此竹林是一个不断增大的碳汇,在陆地生态系统碳循环中起着重要的作用。麻竹因其生长速度快、生物量大、根茎系统发达、生态功能突出等的特点是我国南方栽培最广的竹种之一,而南靖县有“中国麻竹之乡”的美称,是福建省最大的麻竹生产种植区。本文基于地统计学结合ArcGIS 10.0空间分析软件主要研究麻竹土壤植硅体碳的空间变异性,旨在为中国竹林生态系统的土壤植硅体碳汇估测提供科学依据。研究结果表明:(1)麻竹不同层次土壤植硅体碳平均含量介于0.30~0.75 g·kg-1之间,变异系数介于80.38~87.46%均小于1,表现为中等程度的变异性。0~10 cm土层的土壤植硅体碳含量符合高斯模型;10~30 cm、60~100 cm和0~100 cm土层的土壤植硅体碳含量符合指数模型;30~60 cm土层的土壤植硅体碳含量符合球状模型。它们的块基比介于8.7%~74.9%之间,说明具有中等程度的相关性。同时它们的参数比均略小,说明模型拟合度较好。总体来看,麻竹土壤植硅体碳含量的空间分布呈现中高值成片的相间,块状或破碎状的分布。(2)麻竹林0~100 cm土层中储存4.23 t·hm-2的土壤植硅体碳,且各样点土壤植硅体碳储量的差异性较大,最小值仅占最大值的4.85%。各层土壤植硅体碳储量的变异系数均小于1,表现为中等程度的变异性。整体来看,麻竹土壤的植硅体碳储量的平均值且随着土壤深度增加而增大。同时发现0~100cm土层中麻竹和毛竹的土壤植硅体碳储量要高于杉木林、针阔混交林、马尾松林和阔叶林土壤。(3)不同地区土壤剖面中的土壤有机碳、土壤植硅体和土壤植硅体碳含量均随着土壤深度的增加而减少。土壤中PhytOC/SOC的比值是表征长时间(十年至万年)土壤植硅体碳封存机制的一个重要指标,不同地区的土壤中的PhytOC/SOC的比值随着土壤深度的增加而逐渐增加。其原因主要是随着土壤深度的增加,有机碳的降幅大于植硅体碳的降幅。(4)土壤植硅体碳、土壤植硅体和土壤全硅的空间分布图在一定程度上较为相似。同时它们之间也呈极显著正相关关系(P0.01)。麻竹不仅植物部分植硅体碳含量高,其土壤积累植硅体碳的能力也强,可以封存更多的植硅体碳,因此麻竹生态系统在增加土壤稳定性有机碳具有重要意义。样地的竹龄与表层的土壤植硅体碳呈现显著正相关关系(P0.05)。样地的海拔与表层的土壤植硅体碳呈现显著负相关关系(P0.05),说明样地的竹林年龄和海拔是影响土壤植硅体碳的主要因子。
[Abstract]:Because of its super high temperature resistance, oxidation resistance and decomposition resistance, the silicon plant carbon can be stored in soil and sediment for tens of thousands of years under the protection of the hard shell of the plant silicon. Therefore, plant silicon carbon is one of the important sources of stable soil carbon pool, which is of great significance for enhancing soil carbon sink and maintaining global CO2 balance. Forest is the main body of terrestrial ecosystem on earth, but with the rapid decline of global forest area, bamboo forest area is still increasing. Therefore, bamboo forest is an increasing carbon sink and plays an important role in the carbon cycle of terrestrial ecosystem. Because of its fast growth rate, large biomass, well-developed rhizome system and outstanding ecological function, it is one of the most widely cultivated bamboo species in southern China, and Nanjing County has the acclaim of "the township of Chinese hemp bamboo". It is the largest growing area of hemp bamboo in Fujian province. Based on geostatistics and ArcGIS 10.0 spatial analysis software, this paper mainly studies the spatial variability of soil plant silicon carbon in Phyllostachys equisetifolia, in order to provide scientific basis for estimating soil plant silicon carbon sink in bamboo forest ecosystem of China. The results showed that: (1) the average carbon content of soil silicon in different soil layers was between 0.30 and 0.75 g / kg-1, and the coefficient of variation (CV) was 80.38 and 87.46% less than 1, respectively. The soil silicon content in 0 ~ 10 cm soil layer accords with Gao Si's model. The carbon content of soil plant silicon in 10 ~ 30 cm,60~100 cm and 0 ~ 100 cm soil layers is in accordance with exponential model, and the soil silicon content in 30 ~ 60 cm soil layer accords with spherical model. Their block-to-base ratio is between 8.7% and 74.9%, indicating a moderate degree of correlation. At the same time, their parameter ratio is slightly smaller, indicating that the model has a good fitting degree. In general, the spatial distribution of silicon content in soil of Phyllostachys equisetifolia presented a middle-high value interphase, block or fragmentation distribution. (2) the carbon stored in 4.23 t 路hm-2 soil was stored in 0 / 100 cm soil layer of Phyllostachys equisetifolia forest. The carbon storage of plant silicon in soil of different sample sites is different, and the minimum value only accounts for 4.85% of the maximum value. The coefficient of variation of carbon storage in all layers of soil was less than 1, which showed a moderate degree of variability. On the whole, the average carbon storage of plant silicon increased with the increase of soil depth in the soil of Phyllostachys equisetifolia. At the same time, it was found that the soil silicon carbon storage of Phyllostachys pubescens and Phyllostachys pubescens in 0~100cm soil layer was higher than that of Cunninghamia lanceolata, mixed coniferous and broadleaved forests. (3) soil organic carbon in soil profiles of different areas. The carbon content of soil and soil silicon decreased with the increase of soil depth. The ratio of PhytOC/SOC in soil is an important indicator of carbon sequestration mechanism in soil for a long time (from ten to ten thousand years). The ratio of PhytOC/SOC in soils of different regions increases gradually with the increase of soil depth. The main reason is that with the increase of soil depth, the decrease of organic carbon is larger than that of planting silicon. (4) the spatial distribution map of soil plant silicon, soil silicon plant and soil total silicon is similar to some extent. At the same time, there was a very significant positive correlation between them (P0.01). Not only the carbon content of plant silicon in some plants is high, but also the soil accumulation ability of plant silicon carbon is strong, which can store more plant silicon carbon. Therefore, the ecosystem of Phyllostachys equisetifolia has important significance in increasing soil stability organic carbon. There was a significant positive correlation between the bamboo age in the sample plot and the soil silicon plant carbon in the surface soil (P0.05). There was a significant negative correlation between the altitude of the sample plot and the soil silicon content in the topsoil (P0.05), which indicated that the age and altitude of the bamboo forest in the sample plot were the main factors affecting the soil silicon content in the soil.
【学位授予单位】：浙江农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714

【参考文献】