广西天然林赤红壤碳库、营养元素及红外光谱特征研究

发布时间：2018-05-18 15:30

  本文选题：天然林 + 赤红壤　； 参考：《广西大学》2017年硕士论文

【摘要】：随着全球碳循环研究的不断深入,一个区域范围的碳库收支平衡研究也在不断加深。符合采样标准的天然林典型样地较少,本研究选择了 5个广西天然林或次生天然林样地0-80cm赤红壤作为研究对象,进行野外调查采样、对比采样,室内采用物理化学分析法对赤红壤土壤样品进行深入分析对比,测定估算了土壤碳、氮、磷含量和储量,并分析三种元素间的相关关系;同时采用红外光谱分析法、烧失量法分析了赤红壤一些基本特征。研究得到主要结论为:(1)广西天然林赤红壤平均有机碳储量为108.29 t/hm2,分布表现为表层土壤碳储量最高,占整个土壤碳库比例的42%以上,碳含量、碳储量随着土壤深度而降低;化学分组研究表明,惰性碳库慢性碳库活性碳库,土壤有机碳主要是难分解态有机碳为主,所占比例达72%以上;有机碳含量跟土壤母岩、植被类型等密切相关,总的来说天然林下赤红壤干扰少,生物气候条件优越,有机碳含量较高。(2)天然林下赤红壤氮元素分布特征、变化趋势与有机碳相似,氮元素主要是以有机氮的形式存在,氮储量为10.44 t/hm2;土壤母质和土壤的性质、气候条件主要决定了天然林下赤红壤磷库特征,磷元素主要是无机态形式存在,磷储量为8.23 t/hm2;土壤C、N、P元素相关性分析结果表明,赤红壤天然林土壤C与N元素间表现出极显著正相关性,C与P、N与P元素间表现为不显著正相关。(3)赤红壤烧失量特征结果表明,由于表层土壤有机质含量较大,土壤表层烧失量明显大于下层土壤,相比污染较大的化学分析法,烧失量法也可以用于测定有机质含量;在250-350℃间土壤烧失量出现小峰值,而后失量趋于平缓,前期失量主要是腐殖质的分解,同时损失物质可能还有有机质、结合水等;随着温度的升高,土壤损失物质为多糖、纤维素,450℃后失量逐渐增大,主要是多环芳香族类物质的分解,但是仍然包括部分结合水、碳酸盐、二氧化硫等。(4)赤红壤的红外光谱图表现为高岭石型的图谱,表明赤红壤矿物以高岭石为主,伴生矿物有伊利石、蒙脱石、针铁矿物等;赤红壤振动化学键及官能团为:自由水、Al-O-Si、Si-O-Fe、Si-O-Si、C=O、C=C等;其中显著的3695、3620、1035、915cm-1峰以及790cm-1峰可作为用红外光谱判断南亚热带天然林赤红壤特征峰。
[Abstract]:With the development of the global carbon cycle, a regional study of carbon pool balance is becoming more and more important. There are few typical plots of natural forest in accordance with the sampling criteria. In this study, 5 natural or secondary forest plots of 0-80cm red soil were selected as the research objects, and the field investigation and sampling were carried out, and the samples were compared. The soil samples of lateritic red soil were analyzed and compared with each other by physicochemical analysis in laboratory. The contents and reserves of carbon, nitrogen and phosphorus in the soil were measured and estimated, and the correlation between the three elements was analyzed. Some basic characteristics of lateritic red soil were analyzed by burning loss method. The main conclusions are as follows: (1) the average organic carbon storage of red soil in Guangxi natural forest is 108.29 t / hm ~ (2). The distribution shows that the surface soil has the highest carbon storage, accounting for more than 42% of the total soil carbon pool. The carbon content and carbon storage decrease with the depth of the soil. The chemical grouping study showed that the active carbon pool of inert carbon pool, soil organic carbon is mainly indecomposable organic carbon, accounting for more than 72%, the content of organic carbon is closely related to soil parent rock, vegetation type and so on. On the whole, under natural forest, there is little interference, favorable bioclimatic condition, high organic carbon content.) the distribution of nitrogen elements in red soil under natural forest is similar to that of organic carbon, and the nitrogen element mainly exists in the form of organic nitrogen. Nitrogen storage was 10.44 t / hm ~ (-2). Soil parent material, soil properties and climatic conditions mainly determined the characteristics of phosphorus pool in lateritic red soil under natural forest. Phosphorus existed mainly in inorganic form, and phosphorus storage was 8.23 t / hm ~ (2). There was a very significant positive correlation between the elements of C and N in the natural forest soil of lateritic red soil. There was no significant positive correlation between the elements of C and Pu N and P) the results showed that the content of organic matter in the surface soil was higher than that in the surface soil, and the results showed that there was no significant positive correlation between the elements of C and N in the red soil. The amount of burning loss in the surface layer of soil is obviously larger than that in the lower soil. Compared with the chemical analysis method, the method of burning loss can also be used to determine the content of organic matter, and between 250 鈩，

本文编号：1906389