鄱阳湖沙山土壤—植物碳、氮、磷化学计量特征研究

发布时间：2018-06-20 17:51

本文选题：鄱阳湖 + 沙山　；参考：《江西师范大学》2014年硕士论文

【摘要】：鄱阳湖地区作为南方沙化的典型分布区，沙化土地面积达3.89万公顷，主要分布于彭泽、湖口、都昌、星子、永修、新建等滨湖地区。为阐明鄱阳湖典型沙化分布区土壤、植物养分化学计量特征，为沙化土地分布区的植被恢复提供科学依据，本研究于鄱阳湖滨湖都昌县多宝沙山沿沙化梯度测定了17种常见植物叶片、土壤的有机碳(C)、全氮(N)、全磷(P)含量。此外，鉴于湿地松(Pinus elliottii)在过去十几年中已成功引种并大规模栽种于鄱阳湖滨湖沙山，本研究在对沙山整体土壤-植物的C、N、P化学计量特征探讨的基础上，还重点分析了不同林龄湿地松叶片及林下土壤的C、N、P化学计量特征。主要研究结果如下：（1）鄱阳湖沙山土壤有机碳、全氮、全磷含量变化范围分别为0.26%～1.54%，0.014%～0.078%，，0.010%～0.031%。且三者变化模式均表现为随着沙化程度的降低，含量呈逐渐增加的态势。（2）沙山17种主要植物叶有机碳、全氮、全磷变化范围分别为347.9～428.9mg g-1、3.1～22.7mg g-1和0.7～2.1mg g-1，平均值(±标准差)分别为391.3±25.8mg g-1、10.8±4.3mg g-1和1.2±0.4mg g-1。（3）土壤0～10cm、10～30cm、30～50cm层C:N变化范围分别为9.8～46.3、2.4～46.5和3.7～45.0，相应土层C:P范围分别为19.8～75.9、3.0～90.5和4.7～76.5，N:P范围分别为0.4～3.7、0.4～2.9和0.7～3.4。（4）植物C:N、C:P对沙化的响应模式一致，均表现出在重度沙化区数值最小，N:P则表现为在中度沙化区数值最小，C:N、C:P变化主要取决于叶片的N、P含量。土壤C:N随沙化程度增加表现出增加趋势，而C:P、N:P表现出降低趋势。土壤C:N和N:P的变化受控于土壤N含量，C:P变化则决定于土壤有机C含量。（5）10年生湿地松叶片N:P平均值为20.63，10年生以下湿地松叶片N:P平均值为15.61，随着林龄的增加，湿地松生长由N、P共同限制逐渐转向更受P的限制。（6）湿地松叶片C:N、C:P明显高于其它植物，表现出更高的固碳优势和养分利用效率，湿地松的引种对于沙山地表植被覆盖度的快速提高具有明显的效果。沙山湿地松叶片C、N、P及其化学计量比中叶N与C:N对沙化程度和林龄变化反应最为敏感，对于诊断或评估湿地松在沙山的生长状况具有一定的指示作用。
[Abstract]:As a typical distribution area of desertification in the south, Poyang Lake area is 38900 hectares, mainly distributed in Pengze, Hukou, Duchang, Xingzi, Yongxiu, newly built and other littoral areas. In order to elucidate the stoichiometric characteristics of soil and plant nutrients in typical desertification distribution area of Poyang Lake, it provides scientific basis for vegetation restoration in sandy land distribution area. In this study, the contents of organic carbon (C _ (C), total nitrogen (N _ (N), N _ (N), P (P) in leaves of 17 common plant species in Duchang County, Duchang County, Poyang Lake, along the sandy gradient were determined. In addition, in view of the successful introduction of Pinus elliottii (Pinus elliottii) in the past ten years and its large-scale planting in the coastal sand mountains of Poyang Lake, the present study is based on the study of the chemical characteristics of the soil and plants in the sand mountains. The characteristics of CnnP in leaves and soil of Pinus elliottii at different forest ages were also analyzed. The main results are as follows: 1) the change range of soil organic carbon, total nitrogen and total phosphorus in Shashan Mountain of Poyang Lake is 0.26 and 1.54 respectively. With the decrease of desertification degree, the contents of all three change patterns are gradually increasing. (2) the leaf organic carbon and total nitrogen of 17 main plants in Shashan Mountain. The range of variation of total phosphorus is 347.9~428.9mg g-1C 3.1mg g -1 and 0.7~2.1mg g -1, the mean value (卤standard deviation) is 391.3 卤25.8mg g -1 10.8 卤4.3mg g -1 and 1.2 卤0.4mg g -1 respectively. In the corresponding soil layer, the range of C: P was 19.875.93.00.0.5 and 4.777.5N: P were 0.43.70.29and 0.73.4. respectively.) the response pattern of plant C: Nu C: P to desertification was the same. All of them showed that the minimum value of N: P in heavy desertification zone was the minimum value of C _ (1) N _ (1) C _ (P) in moderate desertification zone, and the change of C _ (1) N _ (10) C _ (P) was mainly dependent on the content of N _ (10) P in leaves Soil C: n showed an increasing trend with increasing the degree of desertification, while C: Pu N / P showed a decreasing trend. The change of soil C: n and N: P is controlled by the change of soil N content and C: P content, but the change of soil organic C content is determined by the change of soil N: P content. (5) the average value of N: P in the leaves of 10-year-old Pinus elliottii is 20.63, and the average value of N: P in leaves of Pinus elliottii under 10 years old is 15.61, with the increase of forest age. The growth of Pinus elliottii was gradually changed from the common restriction of Nu P to that of P. (6) the leaves of Pinus elliottii were significantly higher than those of other plants, showing higher carbon sequestration and nutrient utilization efficiency. The introduction of Pinus elliottii has obvious effect on the rapid increase of vegetation coverage. The leaves of Pinus elliottii and their stoichiometric ratios were most sensitive to the change of desertification degree and forest age, and could be used to diagnose or evaluate the growth status of Pinus elliottii in Shashan.
【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：Q948

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