黄土高原退耕优势种柠条叶属性特征的环境响应.docVIP

 黄土高原退耕优势种柠条叶属性特征的环 境响应# 龚春梅，白娟，赵秋琳* 5 10 15 20 25 30 35 （西北农林科技大学生命科学学院，陕西 杨凌 712100） 摘要：植物叶属性特征是具有进化意义的环境适应参数，包括比叶面积、N、P 含量和净光 合速率等。本文拟通过对降水梯度上柠条上述叶属性特征进行系统对比分析，探讨作为黄土 高原优势植物柠条生长发育主要限制因子的水分对柠条叶属性特征的影响程度。采用野外调 查和室内分析相结合的手段，获得以下主要结果：随着干旱胁迫的加剧，杨凌柠条比叶面积 最大，其余研究区的都较低；各研究区柠条叶片比叶面积和净光合速率呈负相关，杨凌柠条 的净光合速率最低，其次是黄陵，而安塞、榆林和神木的都较高；从杨凌到神木，植物 N: P 值变化不明显，而且杨凌柠条 N、P 含量与柠条 N: P 值的相关性均不高，但黄陵和榆林柠 条的 N 含量与柠条 N: P 值显著正相关，而安塞和神木柠条 P 含量与柠条 N: P 值显著负相关。 降水梯度上的各研究区柠条叶属性特征呈现特有的规律性变化。 关键词：植物学；黄土高原；柠条；叶属性；环境响应 中图分类号：Q948.1 Environmental response characteristics of leaf traits in the dominant farmland species Caragana korshinskii on Loess Plateau Gong Chunmei, Bai Juan, Zhao Qiulin (College of Life Science, Northwest A F University, ShanXi YangLing 712100) Abstract: The leaf traits are characterized by the evolutionary parameters of adaptation to the environments, including specific leaf area, N, P content and net CO2 assimilating rate and so on. In this paper, the system comparison analysis on leaf characteristics of Caragana korshinskii along the precipitation gradient was carried out, determining the influence of water which is the main limiting factor as plant growth and development on leaf traits on the Loess Plateau. The field investigation and laboratory analysis was applied integratedly and obtained the following results: Specific leaf area of Caragana korshinskii was the largest in Yangling, but it was relatively low iand was closer to each other in the rest trial sites with the increasing drought stress; meanwhile specific leaf area and net CO2 assimilating rate was negatively correlated among several trail sites, and the net CO2 assimilating rate was the lowest in Yangling, followed by Huangling, however, it was relatively higher in Ansai, Yulin and Shenmu without significant difference; in addition, plant N: P value hadn’t significant change along trial sites, and the correlation between N, P content and N: P value is not significant in Yangling, but N content and N: P valu