Relationships Between Phenomenon of Growing Weakness and Leaf Elements Contents in Pinus tabulaeformis

Abstract

In order to find the relationships between leaf elements contents and phenomenon of growing weakness of plant, the variation of thirteen mineral elements in pine needles were determined at the period from well growth to weak growth for six consecutive years. Twelve elements consisting toxic metals ( Pb , Cr , and Cd ) and essential mineral elements ( P , K , Fe , Mn , Cu , Zn , Ca , Mg and Na ) were analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the N content was analyzed using automatic azotometer (KDY-9820 type). The results showed that there were no significantly variatation in elements N , K , Ca , Mg and Fe between normal and abnormal growing trees. However, the sharply increase of Na and toxic heavy metal Cr , and the gradually decrease of trace elements such as Mn , Cu , Zn , and further the rising of P year by year in pine needles might had much more relationships with the weak growth of Pinus tabulaeformis. The correlations of each element could be used to improve the ratios of different element in order to make plant grow well.