黄土高原子午岭林区两种天然次生林植物叶片-凋落叶-土壤生态化学计量特征

发布时间：2018-04-21 13:23

本文选题：生态化学计量学 + 养分再吸收　；参考：《生态学报》2017年16期

【摘要】：了解我国黄土高原子午岭林区两种天然林下植物叶片-凋落叶-土壤生态化学计量特征,有助于人们更深入地认识黄土高原子午岭天然次生林生态系统养分循环规律和系统稳定机制。结果表明:(1)辽东栎和白桦两种植物叶片碳、氮、磷平均含量为468.6、17.1、2.1 g/kg;凋落叶碳、氮、磷平均含量为457.3、12.5、1.6 g/kg;土壤碳、氮、磷平均含量分别为17.6、1.4、0.5 g/kg。(2)白桦叶片N、P含量之间II类线性回归斜率大于1(P=0.07),表明白桦叶片建成过程中存在N、P元素按比例投入的依赖。白桦凋落叶N、P含量之间的II类线性回归斜率显著小于1(P0.05),两种天然次生林凋落叶整体N、P含量之间的II类线性回归斜率也显著小于1(P0.05),反映了凋落叶中单位P含量与单位N含量间不存在等速损耗关系。(3)黄土高原子午岭两种天然次生林凋落叶氮含量与土壤氮含量具有显著相关性(P0.01),表明凋落叶分解对土壤氮库有增加作用。相比于凋落叶,植物叶片磷含量与土壤磷含量具有较紧密的关系,表现为高的土壤P含量则植物叶片也具有较高的P含量。黄土高原子午岭林区两种天然次生林下土壤有机质具有较快的矿化作用。(4)辽东栎作为植被演替到顶极群落的优势物种,其凋落叶C∶N值为26.7远低于白桦凋落叶C∶N值44.9(P0.05),有利于微生物对凋落叶的分解。两种天然次生林的植物叶片N∶P均值为7.9714,低于全国和全球尺度的其他研究结果,表明这两种天然次生林主要受N限制。
[Abstract]:To understand the characteristics of ecological stoichiometry of two natural plants in Ziwuling forest area of Loess Plateau in China. It is helpful to understand the nutrient cycling law and system stability mechanism of natural secondary forest ecosystem in Ziwuling Loess Plateau. The results showed that the average contents of carbon, nitrogen and phosphorus in leaves of Quercus liaotungensis and Bai Hua were 468.6 and 17.1g / kg, and the average contents of carbon, nitrogen and phosphorus in leaves were 457.3 and 12.5g / kg, respectively. The average phosphorus content of leaves was 17.6 ~ 1.4g / kg 路L ~ (-2) respectively) the slope of class II linear regression between the content of N ~ (2 +) P in Bai Hua leaves was greater than that of 1 ~ (-1) P ~ (-) 0. 07%, which indicated that there was a dependence on the proportion of N ~ (+) P elements in the process of leaf formation of Bai Hua. The linear regression slope of class II between leaves of Bai Hua and natural secondary forest was significantly lower than that of 1P 0.05, and the slope of class II linear regression between the total content of NbP in litter leaves of two kinds of natural secondary forest was also significantly lower than that of 1 P 0.05, which reflected the unit P content and single P content in litter leaves of two kinds of natural secondary forests. There was no isokinetic loss relationship between N content at site. (3) there was a significant correlation between leaf nitrogen content and soil nitrogen content in Ziwuling two natural secondary forests on the Loess Plateau, indicating that litter decomposition had an increasing effect on soil nitrogen pool. Compared with the litter leaves, the phosphorus content of plant leaves was closely related to the soil phosphorus content. The higher P content in soil, the higher P content in plant leaves. The soil organic matter of two natural secondary forests in the Ziwuling forest area of the Loess Plateau has a rapid mineralization.) Quercus liaotungensis is the dominant species of vegetation succession to the climax community. The C _ (1) N value of litter leaves was 26.7 which was much lower than that of Bai Hua's leaves (44.9% P _ (0.05)), which was beneficial to the decomposition of litter leaves by microorganisms. The average value of plant leaf N: P of two natural secondary forests is 7.9714, which is lower than that of other studies on national and global scale, indicating that the two natural secondary forests are mainly restricted by N.
【作者单位】：西北农林科技大学资源环境学院;西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：国家自然科学基金面上项目(41671280) 水利部公益性行业科研专项经费项目(201501045)
【分类号】：S714

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