Abstract:

The variation and correlation of leaf traits can reflect the resource utilization and adaptive survival strategies of plants. In order to explore the traits and variation rules of the leaves of Sophora japonica of different ages， taking the leaves of Sophora japonica of different ages in Liaocheng city as the research object， 13 indicators including the leaf area （LA）， leaf fresh weight （FW）， leaf dry weight （DW）， leaf length （LL）， leaf width （LW）， petiole length （PL）， leaf thickness （LT）， rachis length （RL）， leaf shape index （LI）， specific leaf area （SLA）， leaf dry matter content （LDMC） ， leaf tissue density （LTD）， and specific leaf weight （SLW） were measured， and one-way analysis of variance and coefficient variation analysis were used to explore the characteristics of leaf traits at different tree ages. Principal component analysis and correlation analysis were used to study the adaptation rules of Sophora japonica leaves at different tree ages. The results showed that the DW， LL and PL of reserve resources were significantly higher than those of other tree ages （P<0.01）. The total coefficient variations of 13 leaf traits of Sophora japonica were from 8.57% to 81.48%； among leaf traits of different tree ages， the coefficient variation of the reserve resource LTD was the largest which was 92.86%， and the coefficient variation of the secondary ancient tree LDMC was the smallest which was 5.84%. LA， FW， DW， LL and LW were extremely significantly positively correlated with each other （P<0.01）； SLA was significantly negatively correlated with FW， DW， LTD and SLW （P<0.01）， and positively correlated with LT（P<0.01）； LDMC was significantly positively correlated with FW， DW， LTD and SLW （P< 0.01）. The leaf traits of reserve resources had the characteristics of high LDMC and SLW， low SLA， and belong to the survival strategy of “quick investment-income type”； the secondary ancient trees and the first grade ancient trees showed high SLA， low LDMC and SLW leaf character combinations， and adopted a “slow investment-benefit” and “conservative” strategy. Above results provided a scientific basis for the formulation of maintenance and management strategies for different age classes of Sophora japonica.

Key words: leaf traits, coefficient variation, ancient trees, adaptation strategy, leaf economic spectrum

摘要：

叶片性状的变异与相关关系能够反映植物的资源利用方式和适应生存策略。为探讨不同树龄国槐叶片性状特征及其变异规律，以聊城市不同树龄国槐叶片为研究对象，通过测定叶面积（leaf area， LA）、叶鲜重（leaf fresh weight， FW）、叶干重（leaf dry weight， DW）、叶长（leaf length， LL）、叶宽（leaf width， LW）、叶柄长（petiole length， PL）、叶厚度（leaf thickness， LT）、叶轴长（rachis length， RL）、叶形指数（leaf shape index， LI）、比叶面积（specific leaf area， SLA）、叶干物质含量（leaf dry matter content， LDMC）、叶组织密度（leaf tissue density， LTD）、比叶重（specific leaf weight， SLW）共13项指标，运用单因素方差分析、变异系数分析探究不同树龄叶片性状特征，经相关性分析、主成分分析探究各树龄国槐叶片的适应规律。结果表明，后备资源的DW、LL、PL极显著高于其他树龄的（P<0.01）；国槐13个叶片性状的总体变异系数在8.57%~81.48%，不同树龄叶片性状中后备资源的LTD变异系数最大，为92.86%，2级古树LDMC变异系数最小，仅5.84%；LA、FW、DW、LL和LW呈极显著正相关（P<0.01），SLA与FW、DW、LTD、SLW呈极显著负相关（P<0.01），与LT呈极显著正相关（P<0.01）；LDMC与FW、DW、LTD、SLW呈极显著正相关（P<0.01）；后备资源叶片性状呈高LDMC、SLW，低SLA的特点，采取的是“快速投资-收益型”策略；2级古树和1级古树呈高SLA，低LDMC、SLW的叶片性状组合，采取的是“缓慢投资-收益型”策略。研究结果为制定不同龄级国槐养护管理策略提供科学依据。

关键词: 叶片性状, 变异系数, 古树, 适应策略, 叶经济谱