滇中飒马场小流域不同土地利用条件下群落结构与面源污染输出特征研究

发布时间：2018-03-27 12:17

本文选题：土地利用　切入点：群落结构　出处：《云南大学》2015年硕士论文

【摘要】：土地利用可以改变土地覆被状况并影响许多生态过程。以飒马场小流域为代表的滇中地区,大面积的山地被改造成为坡耕地以种植桉树、茶树、梨树等经济作物,人地关系紧张,生态破坏严重。土地利用的变化,改变了森林水环境效应。研究该区域内土地利用条件下的生态环境效应,对于整个滇中地区的环境整治具有重要的基础数据支持作用。本研究以滇中飒马场小流域内七种不同土地利用模式即灌草丛、云南松林、针阔混交林、常绿阔叶林、桉树林、梨园、茶园为研究对象,结合野外调查和室内分析,研究了不同土地利用条件下的群落结构以及土壤的理化性质特征,及其对面源污染输出的影响。主要结果如下： (1)飒马场流域自然林地(灌草丛、云南松林、针阔混交林、常绿阔叶林)和经济林(桉树林、梨园、茶园)群落结构具有差异。随着群落逐渐复杂,自然林地乔木层各参数指标均逐步增高,而灌木层的各参数则逐步降低。而对于经果林地而言,其变化没有明显差异。经济林同自然林地相比,土地利用强度大,林木密度较自然林地高,但是其群落结构单一,树高较低,物种丰富度较差,枯落物厚度较薄,盖度较小。 (2)不同土地利用模式对土壤物理性质具有影响。通过摄动分析将研究对象同理想模型间差异进行量化,发现常绿阔叶林各项指标综合评价最高,摄动值为0.04,云南松林各项指标综合评价结果最低,摄动值为0.45。具体排序为：常绿阔叶林茶园针阔混交林梨园桉树林灌草丛云南松林。 (3)不同土地利用模式对土壤化学性质具有影响。通过对土壤化学性质进行摄动分析发现,土地面源污染茶园综合源强最高,其摄动值为0.20,而桉树林最低,摄动值为0.41。源强上茶园常绿阔叶林灌草丛针阔混交林梨园云南松林桉树林。 (4)不同土地利用模式对面源污染输出具有影响：五种土地利用类型微小区径流输出范围在38.89-667.22m3/ha之间,SS输出范围在85.10-403.34g/ha之间,总氮输出范围在98.35-1058.82g/ha之间,总磷输出范围在20.32-103.69g/ha之间,总钾输出范围在146.43-4858.81g/ha,COD输出范围在1308.87-41621.37g/ha。坡面尺度同微小区尺度相比,污染物浓度和输移总量有明显下降。 (5)飒马场小流域面源污染总量的输出,受到包括群落结构、土壤物理性质、土壤化学性质各方面的影响。径流是面源污染输移的动力,群落结构和土壤理化性质的改变,均与产流有相关性。在污染物输出总量上,除总氮与土壤物理性质更为密切以外,其它各个指标均与土壤化学性质中的源强相关。
[Abstract]:Land use can change the land cover and affect many ecological processes. In the middle of Yunnan, represented by the small watershed of Sapachang, a large area of mountainous land has been transformed into sloping farmland to plant cash crops such as eucalyptus, tea, pear, etc. The change of land use has changed the effect of forest water environment. It plays an important role in basic data support for environmental improvement in the whole central Yunnan area. In this study, seven different land use patterns, including shrub, pine forest, coniferous and broadleaved forest, evergreen broadleaf forest, eucalyptus forest, pear orchard and tea orchard, were used as the research objects, combined with field investigation and indoor analysis. The community structure and physical and chemical properties of soil under different land use conditions were studied, and their effects on non-point source pollution output were studied. The main results were as follows:. The community structure of natural woodland (shrub grass, Yunnan pine forest, coniferous broadleaved forest, evergreen broadleaved forest) and economic forest (eucalyptus forest, pear orchard, tea garden) is different. The parameters of tree layer and shrub layer of natural forest land increased gradually, but the parameters of shrub layer decreased gradually. However, there was no obvious difference in the change of the parameters of tree layer and shrub layer. Compared with the natural forest land, the land use intensity of economic forest was higher than that of natural forest land. The forest density is higher than that of the natural forest land, but its community structure is single, the tree height is lower, the species richness is poor, the litter thickness is thinner and the coverage is smaller. (2) different land use patterns have influence on soil physical properties. By perturbation analysis, the difference between the study object and the ideal model is quantified, and the comprehensive evaluation of evergreen broad-leaved forest is found to be the highest. The perturbation value was 0.04, and the comprehensive evaluation result of various indexes of Yunnan pine forest was the lowest, and the perturbation value was 0.45. The order was as follows: evergreen broad-leaved tea garden, coniferous and broadleaved mixed forest, pear orchard, eucalyptus forest, shrub grass forest, Yunnan pine forest. 3) different land use patterns have influence on soil chemical properties. The results of perturbation analysis showed that the comprehensive source strength of tea garden polluted by land non-point source was the highest, and its perturbation value was 0.20, while that of eucalyptus forest was the lowest. The perturbation value was 0.41.The evergreen broad-leaved forest in Qiang Shang tea garden was shrub and broad-leaved forest, and the pear orchard was mixed with coniferous and broad-leaved forest in Yunnan pine forest eucalyptus forest. 4) different land use patterns have influence on non-point source pollution output: the runoff output range of five land use types is between 38.89-667.22m3/ha and 85.10-403.34g/ha, total nitrogen output is between 98.35-1058.82g/ha, total phosphorus output range is between 20.32-103.69g/ha, the output range of runoff is between 38.89-667.22m3/ha, total nitrogen output is between 85.10-403.34g/ha, total phosphorus output range is between 20.32-103.69g/ha, total nitrogen output range is 98.35-1058.82g/ha, total phosphorus output range is 20.32-103.69g/ha. The total potassium output ranges from 146.43-4858.81g / ha to 1308.87-41621.37g / ha. Compared with the microcell scale, the pollutant concentration and total transport volume decreased obviously on the slope scale. The output of the total non-point source pollution in the small watershed of Sama Chang is affected by community structure, soil physical properties and soil chemical properties. Runoff is the driving force of non-point source pollution transport, and the change of community structure and soil physical and chemical properties. In the total output of pollutants, except total nitrogen and soil physical properties are more closely related to the source strength of soil chemical properties.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;F301.24

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