摘要 | 按照固氮能力和形态特征,将新疆伊犁天山北坡草本植物群落划分为禾草、杂草和豆科3个功能群,对各功能群植物叶片的N、P含量及N/P比进行比较,并采用相关性分析和冗余分析(RDA)对各指标与环境因子(包括气候、海拔和土壤因子)的关系进行分析。结果表明:新疆伊犁天山北坡草本植物群落总体叶片N、P含量分别为29.02和3.21 g·kg-1,N/P比为10.02。3个功能群间叶片N含量差异显著(P<0.05),以豆科功能群叶片N含量最高,禾草功能群叶片N含量最低;豆科功能群和杂草功能群叶片P含量显著高于禾草功能群;豆科功能群叶片N/P比显著大于其他2个功能群。总体上看,豆科功能群叶片N含量和N/P比均最高,且P含量也较高,各指标的变异系数均最小;而禾草功能群叶片N、P含量均最低,N/P比也较低,各指标的变异系数均最大。相关性分析结果显示:禾草功能群叶片N含量随年均降水量(MAP)的升高而升高,呈显著正相关;杂草功能群叶片N含量随年均温(MAT)的升高而升高,呈显著正相关,P含量则随MAP的升高而降低,呈极显著(P<0.01)负相关;群落总体叶片P含量也随MAP的升高而降低,呈显著负相关。冗余分析结果表明:禾草功能群叶片N、P含量及N/P比受MAP的影响最大;杂草功能群、豆科功能群和群落总体叶片N、P含量及N/P比受土壤全氮含量的影响最大。综合分析结果表明:新疆伊犁天山北坡草本植物群落不同功能群植物的生长均受N限制;不同功能群植物叶片N、P化学计量特征对环境因子的响应程度存在明显差异,表明各功能群的养分利用方式不同。总体上看,年均降水量、海拔和土壤全氮含量是影响新疆伊犁天山北坡3个功能群和群落总体化学计量特征的主要环境因子。 |
Abstract | The herb community at northern slope of Tianshan Mountain in Ili of Xinjiang was divided into three functional groups namely grass, forb, and legume according to nitrogen fixation capacity and morphological characteristics, the contents of N and P and N/P ratio of leaves of each functional group were compared, and correlation analysis and redundancy analysis (RDA) were used to analyze the relationships between each index and environmental factors (containing climate, altitude, and soil factors). The results show that the contents of N and P in leaves of total herb community at northern slope of Tianshan Mountain in Ili of Xinjiang are 29.02 and 3.21 g·kg-1 respectively, and the N/P ratio is 10.02. There are significant (P<0.05) differences in leaf N content among three functional groups, the legume functional group has the highest leaf N content, while the grass functional group has the lowest leaf N content; the leaf P contents of legume and forb functional groups are significantly higher than that of grass functional group; the leaf N/P ratio of legume functional group is significantly higher than those of the other two functional groups. In general, the leaf N content and N/P ratio of legume functional group are the highest, its P content is also relatively high, and the variation coefficient of each index is the smallest; while the contents of N and P in leaves of grass functional group are the lowest, the N/P ratio is also relatively low, and the variation coefficient of each index is the largest. The correlation analysis result shows that the leaf N content of grass functional group increases with the increase of annual mean precipitation (MAP), which shows a significant positive correlation; the leaf N content of forb functional group increases with the increase of annual mean temperature (MAT), which shows a significant positive correlation, and the P content decreases with the increase of MAP, which shows an extremely significant (P<0.01) negative correlation; the leaf P content of total community also decreases with the increase of MAP, which shows a significant negative correlation. The result of redundancy analysis shows that the contents of N and P and N/P ratio of leaves of grass functional group are mostly affected by MAP, those of forb functional group, legume functional group, and total community are mostly affected by soil total nitrogen content. The comprehensive analysis result shows that the plant growth of different functional groups in herb community at northern slope of Tianshan Mountain in Ili of Xinjiang is restricted by N; the responses of leaf N and P stoichiometry characteristics of different functional groups to environmental factors are evidently different, indicating that the nutrient utilization pattern of each functional group is different. In general, annual mean precipitation, altitude, and soil total nitrogen content are the important environmental factors affecting the stoichiometry characteristics of three functional groups and total community at northern slope of Tianshan Mountain in Ili of Xinjiang. |
关键词 | 新疆伊犁天山北坡; 草本植物群落; 功能群; N、P化学计量特征; 环境因子 |
Key words | northern slope of Tianshan Mountain in Ili of Xinjiang; herb community; functional group; N and P stoichiometry characteristics; environmental factor |
作者 | 白悦莹a,b, 许仲林a,b, 徐昕亿a,b |
所在单位 | 新疆大学: a. 地理与遥感科学学院, b. 绿洲生态教育部重点实验室, 新疆 乌鲁木齐 830017 |
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下载次数 | 898 |
基金项目 | 新疆维吾尔自治区高校科研计划(XJEDU2020Y008) |