不同放牧制度草甸草原生态水文特性研究

发布时间：2018-06-08 03:52

  本文选题：不同放牧制度 + 土壤蒸发　； 参考：《内蒙古农业大学》2017年博士论文

【摘要】：呼伦贝尔草原是全世界范围内最大的天然草原,草地水草肥美,与大兴安岭共同构筑了我国北方的生态屏障。但是近年来,随着社会经济持续快速发展,草原上超载放牧现象严重,草原上牲畜-植被-水之间的问题一直困扰着草原的生态环境的和谐发展。本文以呼伦贝尔草原不同放牧草场为研究对象,结合野外测试和模型模拟,调查不同放牧制度草场生态特性及土壤剖面特征,选定相应草场试验场,测定不同放牧制度草场利用方式对植被、土壤、生态环境的影响,通过在试验场模拟降雨试验、土壤蒸发试验、蒸发入渗试验,测定相应的土壤流失量、营养元素流失量、植被截留量和土壤蒸发量等参数。利用有效混合深度模型、改进王彦辉模型、作物系数模型与飞利浦入渗模型等对不同放牧草地的土壤水文状况进行模拟,采用模糊数学法对草地土壤健康状况进行了评价。探讨草地在不同放牧制度影响下土壤水文循环及其生态效应的变化规律,为草地资源的可持续发展提供依据。主要结论如下:(1)三种放牧草场0-80cm深土壤的物理、化学、生物特性差异显著(P0.05),三种放牧草场土壤物理性质变化无明显规律。土壤中氮磷钾等元素含量变化差异较大,总体显示随深度的增加逐渐增大。多酚氧化酶、蔗糖酶、脲酶活性退化程度变化趋势基本一致,均随土壤深度的增加而逐渐减小,且休牧草场轮牧草场自由放牧草场。(2)三种放牧草场土壤入渗率为休牧草场轮牧草场自由放牧草场,有压入渗速率高于无压入渗速率,无压入渗和有压入渗均符合幂函数拟合关系。利用Horton模型、Philip模型、Kostiakov模型模拟不同放牧制度草地土壤入渗过程,其中Horton模型模拟效果最好,Kostiakov模型效果最差。休牧草场土壤蒸发量为0.884mm/day,轮牧草场土壤蒸发量为0.817 mm/day和自由放牧草场土壤蒸发量为0.794 mm/day。土壤含水率与土壤蒸发量相关系数最高为0.503-0.558,参考作物模型计算不同放牧制度草地土壤蒸发量,三种放牧草场土壤蒸发量的计算值和实测值基本变化趋势吻合,自由放牧草场相关系数为0.95,纳什系数为0.76,轮牧草场相关系数为0.92,纳什系数为0.71,休牧草场相关系数为0.91,纳什系数为0.63。(3)休牧、轮牧、自由放牧草场通过水浸泡法测得的截留量分别为0.675mm、0.413mm、0.287mm,降雨模拟实验测得的截留量分别为1.110mm、0.734mm、0.497mm。三种放牧草场整体植被截留量与植被覆盖度和叶面积、降雨量相关性较好,截留量与降雨量呈对数相关关系,与降雨强度间的关系呈抛物线。利用植被的盖度、株高、生物量、叶面积指数与截留量间的关系,建立整体植被截留非线性回归模型,模型的模拟效果较好,相关系数可以达到0.89以上。在非线性回归模型的基础上改进王彦辉模型,对整体植被截留量进行模拟,模拟效果较好相关系数均达到0.9以上。(4)三种放牧草场在相同降雨强度下产流量和产砂量均显示为自由放牧草场轮牧草场休牧草场。降雨强度对不同放牧草场的泥沙流失量影响明显,并且随降雨强度的增加,流失土壤中粘性粒及粉性粒所占比例上升。三种放牧草场总氮流失量为高雨强时自由放牧草场流失最多,轮牧草场次之,休牧草场流失最少,中低雨强时轮放草场与自由放牧草场流失量相近,休牧草场流失最少。三种放牧草场总磷流失量为自由放牧草场最多,休牧草场次之,轮牧草场最少。混合深度模型模拟三种放牧制度草场氮磷流失过程,不完全混合模型的模拟结果优越于完全混合模型,氮流失过程模拟精度小于5%,磷模拟精度小于10%。(5)从土壤物理、化学、生物特性和草地生态水文特性出发对草地进行健康评价,得出休牧草场处于健康状态,轮牧草场处于亚健康状态或健康状态,自由放牧草场处于不健康状态。
[Abstract]:Hulun Buir Grassland is the largest natural grassland in the world. The grassland water grass is rich and the ecological barrier of northern China is built together with Greater Khingan Range. But in recent years, with the rapid and rapid development of the social economy, the overgrazing phenomenon on the grassland is serious. The problem of livestock, vegetation and water on the grassland has been puzzling the ecological ring of the grassland. In this paper, we take the different grazing grassland in Hulun Buir Grassland as the research object, combine the field test and model simulation, investigate the ecological characteristics and soil profile characteristics of different grazing systems, select the corresponding grassland test field, and determine the effects of different grazing systems on the vegetation, soil and the ecological environment. The field simulated rainfall experiment, soil evaporation test and evaporation infiltration test were used to determine the corresponding soil loss, nutrient loss, vegetation interception and soil evaporation. Using the effective mixing depth model, the improved Wang Yanhui model, the crop coefficient model and the PHILPS infiltration model were applied to the soil hydrology of different grazing grassland. The fuzzy mathematical method was used to evaluate the health status of grassland soil. The changes of the soil hydrological cycle and its ecological effects under the influence of different grazing systems were discussed. The main conclusions were as follows: (1) the physical, chemical and biological characteristics of the 0-80cm deep soil in the three pasture pastures were as follows. The variation of soil physical properties of three pasture pastures was not obvious. The changes of the contents of N, P, K and other elements in the soil varied greatly, and the overall show increased with the increase of depth. The trend of the degradation of polyphenol oxidase, sucrase and urease activity was the same, and decreased gradually with the increase of soil depth. (2) the soil infiltration rate of the three grazing pastures is the free grazing grassland in the pasture pasture, and the pressure infiltration rate is higher than the non pressure infiltration rate, the pressure infiltration and the pressure infiltration are all fitted with the power function fitting relationship. The Horton model, the Philip model and the Kostiakov model simulated the different grazing systems. In the process of infiltration of grassland soil, the Horton model has the best simulation effect and the Kostiakov model has the worst effect. The soil evaporation of the Hugh pasture is 0.884mm/day, the soil evaporation of the grazing grassland is 0.817 mm/day and the soil evaporation of the free grazing grassland is 0.794 mm/day., and the correlation coefficient of soil moisture content and soil soil evaporation is the highest for reference. The crop model calculated the soil evaporation in different grazing systems. The calculated values of soil evaporation in three grazing pastures coincided with the measured values. The correlation coefficient of free grazing grassland was 0.95, the Nash coefficient was 0.76, the correlation coefficient of the pasture was 0.92, the Nash coefficient was 0.71, the correlation coefficient of the herd pasture was 0.91, and the Nash coefficient was 0.. 63. (3) herding, rotational grazing and free grazing grassland were measured by water immersion method (0.675mm, 0.413mm, 0.287mm). The interception measured by the simulated rainfall experiment was 1.110mm, 0.734mm, 0.497mm., the total vegetation interception of three grazing pastures was related to the vegetation coverage and leaf area, the rainfall was better, the interception and rainfall were the same. The relationship between several correlation and rainfall intensity is parabola. Using the relationship between vegetation coverage, plant height, biomass, leaf area index and interception, the whole vegetation interception nonlinear regression model is established. The simulation results of the model are better and the correlation coefficient can reach 0.89. On the basis of nonlinear regression model, the improvement of Wang Yanhuimo is improved. The total vegetation interception was simulated. The good correlation coefficient of the simulated results reached more than 0.9. (4) the yield and sand yield of three grazing pastures under the same rainfall intensity were all displayed in the free grazing grassland. The rainfall intensity had a significant effect on the sediment loss in different grazing pastures, and the rainfall intensity was observed with the rainfall intensity. In the three grazing pastures, the total nitrogen loss in the lost soil was increased. The loss of total nitrogen in the grazing grassland was the highest in the high rain intensity, the grazing grassland was the most, the grazing grassland was the least, the low rainfall intensity was close to the free grazing grassland, the loss of the herd pasture was the least. The total phosphorus in the pasture pasture was three. The loss amount is the most free grazing grassland, the rest pasture is the next, and the grazing grassland is the least. The mixed depth model simulates the nitrogen and phosphorus loss process in the three grazing systems. The simulation results of the incomplete mixing model are superior to the complete mixing model, the simulation precision of nitrogen loss process is less than 5%, the phosphorus simulation precision is less than 10%. (5) from soil physics, chemistry and biology. The grassland was in a healthy state, and the grazing grassland was in subhealth or healthy state, and the free grazing grassland was in an unhealthy state.
【学位授予单位】：内蒙古农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S812
，

本文编号：1994332