2021年10月17日 星期日
准噶尔西部山地新疆野苹果叶片化学计量特征及其影响因子分析
Analyses on leaf stoichiometric characteristics and their influencing factors of Malus sieversii in mountainous area of west Junggar Basin
2020年 第29卷 第5期 页码[48-57]    下载全文[0.8MB]  
摘要

以位于准噶尔西部山地的额敏县、托里县和裕民县16个样方84株新疆野苹果〔Malus sieversii (Ledeb.) Roem.〕为研究对象,对叶片的C、N、P、K含量及化学计量比在不同年份、县、放牧强度和枯枝率间的差异进行比较,并对27个环境因子和6个个体生长指标与上述叶片化学计量指标的相关性进行分析。结果表明:在2017年,新疆野苹果叶片C、N和K含量分别为462.77、18.69和14.95 mg·g-1,显著(P<0.05)高于2016年;C/P比、N/P比和N/K比分别为325.33、12.99和1.37,也显著高于2016年;但C/N比和P/K比分别为26.15和0.11,显著低于2016年。除C含量外,其余9个化学计量指标在3个县间差异显著。重度放牧下叶片K含量显著高于其余放牧强度,而C/K比和P/K比显著低于其余放牧强度;中度放牧下叶片N含量和N/P比显著低于其余放牧强度,而C/N比显著高于其余放牧强度。低枯枝率下叶片C含量、N含量、C/P比、N/P比和N/K比显著高于其余枯枝率,而高枯枝率下叶片P含量和P/K比显著高于其余枯枝率。相关性分析结果表明:经度、放牧强度、年均降水量以及土壤的全氮含量(Ns)、全钾含量(Ks)、速效氮含量(ANs)和ANs/AKs比与多数叶片化学计量指标显著或极显著(P<0.01)相关,说明这些因子是影响新疆野苹果叶片化学计量特征的主要环境因子。总体来看,个体生长指标与叶片化学计量指标的相关性较高,尤其是投影盖度、病虫害程度和枯枝率。结果显示:准噶尔西部山地新疆野苹果叶片化学计量特征在不同年份、县、放牧程度和枯枝率间差异明显。该区域新疆野苹果生长主要受N限制,应采取适度放牧、加强病虫害防治及增施氮肥等措施,促进植株生长、缓解养分限制。

Abstract

 Taking 84 plants of Malus sieversii (Ledeb.) Roem. from 16 plots in Emin County, Toli County, and Yumin County in mountainous area of west Junggar Basin as research objects, differences in C, N, P, and K contents and their stoichiometric ratios in leaf among different years, counties, grazing intensities, and dead branch rates were compared, and correlations of 27 environmental factors and 6 individual growth indexes with above leaf stoichiometric indexes were analyzed. The results show that in 2017, C, N, and K contents in leaf of M. sieversii are 462.77, 18.69, and 14.95 mg·g-1, respectively, and significantly (P<0.05) higher than those in 2016; C/P ratio, N/P ratio, and N/K ratio are 325.33, 12.99, and 1.37, respectively, and also significantly higher than those in 2016; but C/N ratio and P/K ratio are 26.15 and 0.11, respectively, and significantly lower than those in 2016. Except for C content, other 9 stoichiometric indexes among 3 counties are significantly different. Under heavy grazing, K content in leaf is significantly higher than that under other grazing intensities, while C/K ratio and P/K ratio are significantly lower than those under other grazing intensities; under moderate grazing, N content and N/P ratio in leaf are significantly lower than those under other grazing intensities, while C/N ratio is significantly higher than those under other grazing intensities. C content, N content, C/P ratio, N/P ratio, and N/K ratio in leaf under low dead branch rate are significantly higher than those under other dead branch rates, while P content and P/K ratio in leaf under high dead branch rate are significantly higher than those under other dead branch rates. The correlation analysis result shows that longitude, grazing intensity, annual mean precipitation, and total nitrogen content (Ns), total potassium content (Ks), available nitrogen content (ANs) and ANs/AKs ratio of soil are significantly or extremely significantly (P<0.01) correlated with most leaf stoichiometric indexes, indicating that these factors are the major environmental factors affecting leaf stoichiometric characteristics of M. sieversii. Overall, individual growth indexes are highly correlated with leaf stoichiometric indexes, especially projective coverage, disease and insect pest degree, and dead branch rate. It is suggested that leaf stoichiometric characteristics of M. sieversii in mountainous area of west Junggar Basin are evidently different among different years, counties, grazing intensities, and dead branch rates. Growth of M. sieversii in this area is mainly limited by N, and measures of moderate grazing, strengthening of disease and insect pest control, and increasing nitrogen fertilizer application, etc. should be adopted to promote plant growth and relief nutrient limitation.

关键词新疆野苹果; 叶片化学计量指标; 环境因子; 个体生长指标; 相关性分析
Key wordsMalus sieversii (Ledeb.) Roem.; leaf stoichiometric index; environmental factor; individual growth index; correlation analysis
作者高雯萱, 张静, 周晓兵, 陶冶
所在单位中国科学院新疆生态与地理研究所 荒漠与绿洲生态国家重点实验室, 新疆 乌鲁木齐 830011
点击量667
下载次数122
基金项目国家林业和草原局珍稀濒危物种野外救护与人工繁育项目(2019); 国家林业和草原局生物安全与遗传资源管理项目(KJZXSA202031)