Study on Dynamic Comparation of Single Leaf and Their Correlation of Cercidiphyllum japonicum

Dynamic comparation of single leaf in fast-growing period and their correlation of chlorophyll content of Cercidiphyllum japonicum of one year old seedlings was studied,including the indexes of leaf length,leaf width,petiole length,leaf area,leaf thickness and chlorophyll content. The results showed that the increasing duration of average leaf area was 22 d. The average growth rate 1.98 cm2/d,The development trend of leaf length,leaf width,petiole length,leaf area and chlorophyll content was August July June.The change of the leaf expansion rate took was fluctuating,the highest value reached to 41.4% per day;the larger of mature leaf area,the slower of the leaf expansion rate. The correlation analysis between leaf expansion rate and leaf length,leaf width,petiole length,leaf area and leaf thickness showed that the leaf expansion rate had very significant negative correlation with leaf length,leaf width,petiole length,leaf area and chlorophyll content,at P =0.01 level,leaf area has very significant positive correlation with leaf length,leaf width,petiole length and chlorophyll content at P=0.01 level,the relationship between leaf area of katsura tree and growth time did accord with S curve model in different fast-growing period.