中亚热带南酸枣落叶阔叶林土壤磷素空间分异及其影响因素

发布时间：2018-06-13 04:53

本文选题：南酸枣落叶阔叶林 + 土壤磷　；参考：《中南林业科技大学》2016年硕士论文

【摘要】：我国中亚热带地区水热条件良好,自然环境优越,自然资源丰富,是我国重要的农林生产基地,在保护环境、维持人类可持续发展等方面发挥着重要的作用。土壤P素是极为重要土壤养分之一,是植物生长发育不可缺少的营养元素,能够促进各种代谢正常进行,影响着植物的生长和发育,一定程度上影响着森林林木的生长以及森林生产力的提高。对土壤P素的空间异质性研究,是探讨土壤P素与环境因子之间关系的有效方法,能够有助于我们了解土壤结构的形成,探究土壤的理化性质和土壤功能。本研究在南酸枣(Choerospondias axillaris)落叶阔叶林建立1 hm2固定样地,基于植物群落学调查数据和等距离网格布点取样的土壤养分测定数据,采用地统计学和GIS相结合的方法,研究土壤P含量的空间变异特征及其与地形因子、生物因子、土壤因子的关系,为揭示亚热带森林土壤P空间分布的调控机制,为亚热带森林健康经营与管理提供了科学依据。研究结果表明：(1)南酸枣落叶阔叶林样地地形因子、生物因子及土壤因子均呈正态分布,概率密度与频数分布较为集中,地形因子中高程范围在4.00～51.80 m,变异系数43.04%,凹凸度在-2.48～2.06之间,变异系数61.42%,均达到中等程度变异；生物因子中凋落物现存量在2.03 t·hm-2～16.50 t·hm-2之间,变异系数48.74%,物种数及植株数范围分别在1.00～13.00和2.00～44.00之间,变异系数分布为32.55%和48.66%,达到中等程度变异；土壤因子中含水率在25.37%～46.27%之间,变异系数9.17%,土壤pH在4.02～4.69之间,变异系数3.43%,均为弱程度变异,有机C、全N含量在16.33～116.81g·kg-1、1.60～3.83g·kg-1之间,变异系数35.94%及17.8%,均达到中等程度变异。(2)样地腐殖质层、0-10、10-20、20-30 cm土层全P含量范围在0.12～0.54g·kg-1,平均值分别为0.36、0.29、0.27、0.23g·kg-1,变异系数分别为19.10%、23.95%、28.22%、28.84%;土层有效P含量范围在4.88-22.29mg·kg-1,平均值分别为12.13、2.46、2.63、1.90mg·kg-1,变异系数分别为31.36%、35.40%、40.69%、44.95%；全P、有效P含量均达到了中等强度变异,随着土壤深度增加,全P、有效P含量下降,变异程度增大,同一土层有效P含量的变异幅度较全P含量高；各土层土壤全P半方差函数的理论模型符合指数模型、球状模型和高斯模型；有效P半方差函数的理论模型符合指数模型以及球状模型；在中等尺度范围上,土壤全P、有效P含量表现出中等强度的空间自相关性,表明空间异质性主要是由结构性因素引起的。(3)各土层全P含量变程为92.800～168.900 m,有效P含量变程为79.430-106.200 m,全P含量较有效P含量具有较大的空间自相关性尺度,空间连续性较高于有效P；土壤全P含量分维数范围在1.86-1.978之间,土壤有效P含量分维数范围在1.803-1.869之间,这表明土壤全P、有效P含量均具有良好的分形特征,有效P含量分维数较全P分维数低,具有更好的结构性,空间分布更加简单,而全P的空间格局相对复杂。各土层全P、有效P含量呈明显的条带状和斑块状梯度性分布,在一些小样地内为相似的空间分布格局。(4)土壤全P、有效P含量与高程均呈显著和极显著负相关,与凹凸度也呈负相关,但除20-30cm土层全P达到极显著负相关外,其余土层均未达到显著水平。土壤全P、有效P含量与地表凋落物现存量呈显著负相关,与样地植物种数呈负相关,除20-30 cm土层全P含量与植物种数呈显著相关外,其他各土层均未达到显著水平,与样地植物株数不存在相关性。土壤全P含量与土壤含水率呈负相关,除0-10 cm土层全P含量与含水率呈极显著负相关外,其他各土层均未达到显著水平;土壤有效P含量与土壤含水率呈正相关关系,除0-10 cm土层有效P含量与含水率呈显著相关外,其他土层均未达到显著水平；土壤全P、有效P含量与土壤pH呈正相关,除腐殖质层全P含量、0-10cm土层全P、20-30cm土层有效P含量外,其他土层与土壤pH相关性均未达到显著水平；土壤全P、有效P与土壤有机C、全N均呈极显著正相关。可见,土壤P素空间分异特征是受到多种环境因子综合作用的。
[Abstract]:In the middle and subtropical regions of China, the water and heat conditions are good, the natural environment is superior, and the natural resources are rich. It is an important agricultural and forestry production base in China. It plays an important role in protecting the environment and maintaining the sustainable development of human beings. Soil P is one of the most important soil nutrients, which is an indispensable nutrient element for plant growth and development, and can promote the growth and development of plants. A variety of normal metabolism affects the growth and development of plants and affects the growth of forest trees and the increase of forest productivity to a certain extent. The study of spatial heterogeneity of soil P elements is an effective method to explore the relationship between soil P and environmental factors, which can help us to understand the formation of soil structure and explore the soil. In this study, 1 hm2 fixed plots were set up in the deciduous broadleaf forest of Choerospondias axillaris. Based on the data of plant community study and the measured data of soil nutrients sampled at the same distance grid, the spatial variation characteristics of the soil P content were studied by the combination of geostatistics and GIS. The relationship between the topographic factors, biological factors and soil factors to reveal the regulation mechanism of the spatial distribution of P in subtropical forest soil provides a scientific basis for the healthy management and management of subtropical forests. The results show that: (1) the terrain factors, biological factors and soil factors in the deciduous broad-leaved forest of the South sour jujube are all positive distribution, the probability density and the probability density. The frequency distribution is more concentrated, the height range of topographic factors is 4 to 51.80 m, the coefficient of variation is 43.04%, the concave and convex degree is between -2.48 and 2.06, the coefficient of variation is 61.42%, and the variation coefficient is moderate to the moderate degree. The litter size of the biological factor is between 2.03 t. Hm-2 to 16.50 t. Hm-2, the variation coefficient is 48.74%, the number of species and plant number are 1, respectively. Between 13 and 2 to 44, the variation coefficient is 32.55% and 48.66%, and the soil moisture content is between 25.37% and 46.27%, the coefficient of variation is 9.17%, the soil pH is 4.02 to 4.69, the coefficient of variation is 3.43%, and the organic C and all N content are between 16.33 ~ 116.81g. Kg-1,1.60 to 3.83g kg-1. The variation coefficient 35.94% and 17.8%, all reach the medium degree variation. (2) the ground humus layer, the 0-10,10-20,20-30 cm soil layer whole P content range is 0.12 ~ 0.54g. Kg-1, the average value is respectively 0.36,0.29,0.27,0.23g kg-1, the variation coefficient is 19.10%, 23.95%, 28.22%, 28.84% respectively, the soil layer effective P content range is 4.88-22.29mg. Kg-1, the average value is respectively 12.13,2.46,2.63,1.90mg. Kg-1, the coefficient of variation was 31.36%, 35.40%, 40.69%, 44.95%; all P, the content of effective P reached medium intensity variation. As the soil depth increased, all P, the content of effective P decreased, the variation degree increased, the variation amplitude of the effective P content in the same soil layer was higher than that of the whole P; the whole P half variance function of the soil layer soil was full. The model conforms to the exponential model, the spherical model and the Gauss model; the theoretical model of the effective P semi variance function conforms to the exponential model and the spherical model. On the medium scale, the soil P and the effective P content show the medium intensity spatial autocorrelation, indicating that the spatial heterogeneity is mainly caused by the structural factors. (3) the whole soil layer is all the soil layer. The content variation of P was 92.800 ~ 168.900 m, the content of effective P content changed to 79.430-106.200 m, the total P content had larger spatial autocorrelation scale than the effective P content, and the spatial continuity was higher than that of the effective P; the whole soil P content fractal dimension range was between 1.86-1.978, and the effective P content of soil was between the 1.803-1.869. The content of effective P has a good fractal feature. The fractal dimension of effective P content is lower than that of all P fractal dimension. It has better structure and more simple spatial distribution, while the spatial pattern of all P is relatively complex. All soil layers are P, the effective P content is obviously striped and patch like gradient distribution, and a similar spatial distribution pattern in some small plots. (4) the soil all P, the effective P content and elevation are significantly and significantly negative correlation, and the degree of concave and convex is also negative correlation, but in addition to the 20-30cm soil layer all P is extremely significant negative correlation, the other soil layers are not reached significant level. The soil all P, the effective P content is negatively correlated with the ground litter size, except for the number of plant species negative correlation, except 20-30. The total P content in the cm soil layer was significantly related to the number of plant species, and the other soil layers did not reach the significant level, and there was no correlation with the number of plant plants. The total P content in soil was negatively correlated with soil moisture content. Except the total P content in the 0-10 cm soil layer was negatively correlated with the water content, the soil layers were not significantly higher than that of the soil, and the effective soil P contained the soil layer. There is a positive correlation between the soil moisture content and the soil moisture content, except that the effective P content of the 0-10 cm soil layer is significantly correlated with the water content, and all the other soil layers have not reached a significant level. The total soil P, the effective P content is positively correlated with the soil pH, except the total P content in the humus layer, the 0-10cm soil whole P, the effective P content of the 20-30cm soil layer, and the pH correlation between the other soil layers and the soil. The soil all P, effective P and soil organic C and all N have significant positive correlation. It is obvious that the spatial differentiation characteristics of soil P are integrated with various environmental factors.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S714

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