祁连山青海云杉林群落结构特性及养分特征研究

发布时间：2018-04-30 01:13

本文选题：青海云杉林 + 动态观测大样地　；参考：《甘肃农业大学》2016年博士论文

【摘要】：祁连山区气候呈大陆性高寒半干旱、半湿润特点,分布在其阴坡、半阴坡的森林植被除了受恶劣的气候影响外,还受地形、土壤、干扰和生物学特性的综合影响,森林生态系统环境较为脆弱,生态系统的稳定性和抗干扰性差。加上人类活动的长期干扰,该区森林生态系统退化严重,服务功能降低,逆向演化显著,进程加快,给区域生态环境建设和经济发展带来了负面影响。通过对祁连山森林结构特性和养分特征进行研究,有助于了解恢复和重建受损的森林生态系统,对森林植被恢复的合理调控具有一定的科学意义,从而更好的发挥其在生态服务功能中的作用。本文以分布在祁连山大野口流域的青海云杉林群落为研究对象,以森林生态学、土壤学、化学计量学等学科理论为指导,通过对祁连山森林生态站建立的祁连山青海云杉林动态观测大样地和设在不同海拔梯度固定样地的植被调查,叶片和枯落物及土壤养分的室内测定,应用经典数理统计分析方法,研究揭示了青海云杉林林分结构特点、群落结构的空间异质性、土壤养分的空间异质性和变化规律、土壤有机碳与养分之间的关系,进而分析了青海云杉林生态系统内碳、氮、磷在叶片—枯落物—土壤间的相互作用规律与机制。主要结论如下:(1)祁连山青海云杉林动态观测大样地高等植物共有30科63属88种,主要以菊科、蔷薇科、唇形科、龙胆科、玄参科、豆科、毛茛科等为主。森林垂直结构明显,分乔木层、灌木层、草本层和苔藓层。青海云杉林径级结构呈倒“J”型,无明显断层现象,林木更新良好。小树空间分布格局表现为明显的聚集分布,中树空间分布呈轻微的聚集分布,而大树分布表现为明显的随机分布,同时不同径级的青海云杉林个体之间具有空间分布互补性。(2)祁连山青海云杉林动态观测大样地青海云杉林5个结构属性的变异程度大小依次为密度平均冠幅显著度盖度平均树高,变异系数为43.7%~79.6%。Moran′s系数表明各个结构属性均有不同程度的空间自相关性,自相关大小顺序为密度平均树高盖度平均冠幅显著度,变化范围为-0.047~0.382。指数理论变异函数模型能很好地拟合不同结构属性的空间变异,变程为24.6~68.1 m,各属性变量的结构比除盖度表现为中等空间相关,其他指标均为强烈空间相关,各属性指标分维数接近2,空间依赖性较小。植被密度和盖度空间分布呈带状结构和斑块结构叠加的特点,其他指标呈较强的斑块状空间结构,密度和盖度对平均冠幅、显著度和平均树高有一定的空间依赖性。青海云杉林群落结构空间异质性适宜的采样间隔和采样面积分别为10m和0.5hm2。(3)祁连山青海云杉林动态观测大样地土壤ph、水解氮和全磷为弱变异性,有机碳、全氮、速效磷、全钾和速效钾为中等变异性,它们的大小依次为速效钾有机碳速效磷全氮全钾水解氮全磷ph。半方差最优模型拟合分析表明,ph、全氮、水解氮、全磷、速效磷和速效钾均符合球状模型,有机碳和全钾均符合指数模型;ph、有机碳、全氮、水解氮、全磷、速效磷、全钾和速效钾的变程依次为108.8m、88.5m、112.8m、131.9m、143.3m、73.3m、73.2m和134.7m。从空间结构特征看,ph具有中等强度的空间自相关,而养分表现出强烈的空间自相关。ph和养分均呈斑块状分布,有机碳和氮素具有相似的空间分布格局,全磷和速效钾分布变化较为明显,速效磷和全钾分布变化较为平缓。上述研究结果可为祁连山青海云杉林土壤ph和养分的取样设计和空间分布图制作等提供参考。(4)祁连山青海云杉林动态观测大样地不同土层有效微量元素锌、锰、铜、铁、硼的平均含量大小顺序均为:铁锰铜硼锌,有效微量元素均具有明显的“表聚效应”。0~60cm土层有效锌、锰、铜、铁、硼均值大小分别为:0.52±0.27mg·kg-1、6.26±1.76mg·kg-1、2.44±0.98mg·kg-1、94.69±25.48mg·kg-1、2.19±0.70mg·kg-1。0~60cm土层中,锌、锰、铜、铁、硼密度大小分别为:2.21±1.27mg·m-2、26.24±7.64mg·m-2、11.50±6.41mg·m-2、447.78±178.04mg·m-2、9.76±3.32mg·m-2,有效性指数大小为:铁硼铜锰锌,其中:铁、硼、铜有效性指数大于1,而锌、锰有效性指数小于1。不同土层有机质与锌、锰、铜、铁、硼等均呈显著或极显著正相关,ph值与锌、锰、铜、铁、硼等均呈显著或极显著负相关,速效磷仅与硼呈极显著正相关,有机质和ph值均对有效微量元素含量具有重要影响。(5)祁连山青海云杉林动态观测大样地随土层深度不断增加,土壤有机碳含量逐渐减小,到20~30cm以下趋于稳定(p0.05);土壤ph值不断增大,仅在0~10cm与10~20cm差异显著(p0.05);土壤全氮、速效氮、全磷和阳离子交换量不断减小,全氮含量到30~40 cm以下趋于稳定(p0.05),速效氮含量变化剧烈(p0.05),全磷含量差异性不显著(p0.05),阳离子交换量与有机碳含量变化规律相同;土壤速效磷、全钾和速效钾含量没有明显的变化规律,速效磷和全钾含量差异性不显著(p0.05),速效钾含量仅在0~10 cm与10~20 cm差异显著(p0.05)。土壤有机碳与全氮、速效氮、全磷、速效磷、速效钾和阳离子交换量之间呈极显著和显著正相关,与土壤pH值和全钾含量之间呈极显著和显著负相关。土壤有机碳与其他基本化学性质的回归方程具有较高精度(R2=0.793),影响土壤有机碳含量主要化学因子依次为:土壤阳离子交换量、速效钾和全磷含量。(6)在不同海拔梯度上,青海云杉林叶片、枯落物和土壤C:N比的变化范围分别为22.95~36.72、21.41~41.61、12.41~20.70,均值大小依次为枯落物叶片土壤,C:P和N:P比的变化范围分别为510.2~739.8、398.6~698.1、134.1~219.7和18.13~26.86、6.71~26.28、7.96~16.56,均值大小依次均为叶片枯落物土壤。随海拔梯度的增加,除土壤C:N比差异性不显著外(p0.05),叶片和枯落物的碳、氮、磷化学计量比在不同海拔间的差异显著性各不相同。叶片、枯落物和土壤C:N比两两均具有显著正相关(p0.05),叶片与枯落物及土壤与枯落物C:P比均具有显著负相关(p0.05),叶片与土壤C:P比及不同组分N:P比之间相关性均不显著(p0.05)。该研究结果有助于进一步了解青海云杉林碳、氮、磷在不同组分间的相互作用规律与机制。
[Abstract]:The climate of Qilian mountain area is characterized by semi-arid and semi-arid, semi humid and semi humid, which is distributed in its shady slope. In addition to the adverse climate, the forest vegetation in the semi shady slope is affected by the comprehensive effects of terrain, soil, interference and biological characteristics. The environment of the forest ecosystem is relatively fragile, the stability and anti-interference of the biological system are poor. Long term interference, the forest ecosystem in this area is degraded seriously, the service function is reduced, the reverse evolution is significant, the process is accelerated, and the ecological environment construction and economic development of the region have been negatively affected. Through the study of the characteristics of the forest structure and the nutrient characteristics of the Qilian Mountains, it is helpful to understand the restoration and reconstruction of damaged forest ecosystem, and to the forest. The rational control of vegetation restoration has certain scientific significance, thus better play its role in the ecological service function. In this paper, the Qinghai spruce forest community, distributed in the great wild river valley of Qilian Mountains, is the research object, guided by the theory of forest ecology, soil science and chemometrics, through the forest Ecological Station of Qilian Mountains. The dynamic observation of the vegetation of Qinghai spruce forest in Qilian Mountains, the vegetation survey, the indoor determination of leaves and litter and soil nutrients, and the application of classical mathematical statistics and analysis methods were used to reveal the structure characteristics of the spruce forest in Qinghai, the spatial heterogeneity of the colony structure and the spatial difference of soil nutrients. The relationship between soil organic carbon and nutrients, and then the interaction rules and mechanisms of carbon, nitrogen and phosphorus in leaf litter and soil in Qinghai spruce forest ecosystem. The main conclusions are as follows: (1) there are 88 species, 63 genera, 30 families, and 63 genera in 30 families of large plants of spruce forest in Qilian Mountains. Rosaceae, lip family, gentioparae, Radix scararopicaceae, leguminosaceae, Leguminosae, Ranunculaceae, etc., the vertical structure of the forest is obvious, divided into arbor layer, shrub layer, herbaceous layer and moss layer. The diameter class structure of Qinghai spruce forest is inverted "J" type, there is no obvious fault phenomenon, and the tree is well updated. The spatial distribution pattern of small trees is obvious and the spatial distribution of middle tree is distributed in the spatial distribution of the middle tree. The distribution of the trees in the Qinghai spruce forests of different sizes has the spatial distribution complementation. (2) the variation degree of the 5 structural attributes of the spruce forest in the Qilian Mountains Qinghai spruce forest is in accordance with the average canopy density average tree height of the density average crown. The coefficient of variation is 43.7%~79.6%.Moran 's, which indicates that all the structural attributes have different degrees of spatial autocorrelation, and the order of autocorrelation is the average height of the average canopy of the density average tree, and the variation range of the -0.047~0.382. exponent theory variation function model can well fit the spatial variation of the different structural attributes, and the variation range is 24.6. ~68.1 m, the structure of each attribute variable is relative to the average space, and the other indexes are strongly spatial correlation. The fractal dimension of each attribute is close to 2 and the spatial dependence is small. The spatial distribution of vegetation density and coverage is characterized by the superposition of strip structure and patch structure. The suitable sampling interval and area of spatial heterogeneity of Qinghai spruce forest community structure are 10m and 0.5hm2. (3) the dynamic observation of soil pH in Qilian Mountains Qinghai spruce forest in Qilian Mountains, and the weak variability of hydrolyzed nitrogen and total phosphorus, organic carbon, total nitrogen, available phosphorus and total potassium. And quick acting potassium is medium variation, and their size is the best fitting analysis of pH. semi variance model of total potassium hydrolysate nitrogen of quick acting potassium organic carbon. The results show that pH, total nitrogen, hydrolyzed nitrogen, total phosphorus, available P and available K all conform to the spherical model, and both organic carbon and total potassium are in conformity with the exponential model; pH, organic carbon, total nitrogen, hydrolyzed n, total phosphorus, The variation of available phosphorus, total potassium and available potassium is 108.8m, 88.5m, 112.8m, 131.9m, 143.3m, 73.3m, 73.2m and 134.7m. have medium spatial autocorrelation from the spatial structure characteristics, and the nutrients show strong spatial autocorrelation.Ph and nutrient patches like distribution, organic carbon and nitrogen have similar spatial distribution pattern, total phosphorus. The distribution of available potassium is more obvious, and the distribution of available phosphorus and total potassium is relatively gentle. The above results can provide reference for the sampling design and spatial distribution map of the soil pH and nutrients in Qinghai spruce forest. (4) the dynamic observation of the effective trace elements zinc, manganese, copper, iron and boron in the Qinghai spruce forest in Qilian Mountains. The order of the average content is: Fe, Mn, Cu, B and Zn, the effective trace elements have obvious "surface accumulation effect".0~60cm soil effective zinc, manganese, copper, iron and boron are respectively: 0.52 + 0.27mg. Kg-1,6.26 + 1.76mg. Kg-1,2.44 + 0.98mg. Kg-1,94.69 + 25.48mg. Kg-1,2.19 + 0.70mg. Kg-1.0~60cm soil layer, zinc, manganese, copper, iron, boric density The size is 2.21 + 1.27mg. M-2,26.24 + 7.64mg. M-2,11.50 + 6.41mg m-2447.78 + m-2,9.76 + 3.32mg. The effectiveness index is: Fe, B, Cu, Mn and Zn, of which iron, boron, copper are more than 1, while Zn, Mn efficiency index is less than 1. different soil organic matter and zinc, manganese, copper, iron, boron and so on are all significant or extremely significant Positive correlation, pH value has significant or extremely significant negative correlation with zinc, manganese, copper, iron, boron and so on. Available P only has a significant positive correlation with boron, organic matter and pH value have important influence on the content of effective trace elements. (5) the dynamic observation of Qinghai spruce forest in Qilian Mountains is increasing with the depth of soil layer, the soil organic carbon content gradually decreases, to 20~ The pH value below 30cm tends to be stable (P0.05), and the soil pH value is increasing, only in 0~10cm and 10~20cm (P0.05); the total nitrogen, available nitrogen, total phosphorus and cation exchange decrease, the total nitrogen content is stable (P0.05) below 30~40 cm (P0.05), the content of available nitrogen changes violently (P0.05), the total phosphorus content is not significant (P0.05), cation exchange quantity The content of soil available phosphorus, total potassium and available potassium did not change obviously. The difference of available phosphorus and total potassium content was not significant (P0.05). The content of available potassium was only significant difference between 0~10 cm and 10~20 cm (P0.05). Soil organic carbon and total nitrogen, available nitrogen, total phosphorus, available phosphorus, available potassium and cation exchange amount There was a significant and significant positive correlation between the soil pH and total K content. The regression equation of soil organic carbon and other basic chemical properties was of high accuracy (R2=0.793). The main chemical factors affecting soil organic carbon content were as follows: soil soil cation exchange, available potassium and total phosphorus content. (6) At different altitudes, the variation range of leaf, litter and soil C:N ratio of Qinghai spruce forest was 22.95~36.72,21.41~41.61,12.41~20.70, respectively, the mean size was the litter leaf soil, and the range of C:P and N:P ratio was 510.2~739.8398.6~698.1134.1~219.7 and 18.13~26.86,6.71~26.28,7.96~16.56, respectively. In addition to the elevation gradient, except for the C:N ratio of soil, the carbon, nitrogen and phosphorus ratio of leaves and litter are different at different altitudes. Leaves, litter and soil C:N have significant positive correlation (P0.05), leaves and litter, soil and litter, as well as soil C:N (P0.05). The C:P ratio has significant negative correlation (P0.05), and the correlation between the leaf and soil C:P ratio and the N:P ratio of different components is not significant (P0.05). The results of this study are helpful to further understand the interaction rules and mechanisms of carbon, nitrogen and phosphorus in Qinghai spruce forest.

【学位授予单位】：甘肃农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S791.18

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