关键词: 杉木, 叶绿素, 精氨酸, 林龄, 立地条件, 立木级

Abstract: During the period 1987-1988, 6 plots representing 5, 10,and 20-year-old Chinese fir stands with good and poor site quality were laid out in Fudong Branch of Fengshushan Forest Station,Jiangxi province,and the differences of chlorophyll, arginine and ammonia nitrogen contents in needles and twigs of different tree classes among the stands of different ages on various sites during different seasons were studied. There were significant differences in chlorophyll content in needles during bud flush and pre-dormancy among the stands of different ages, but insignificant during fast-growing seasons.Chlorophyll content in needles during fast-growing seasons was much higher than that during bud flush and pre-dormancy,especially during the second fast-growing season. It was generally higher on the good sites than that on the poor sites during all seasons in all stands. It reached 2.50,2.24,and 2.14.mg/gf.w.in the needles of dominant trees on the good sites in 5, 10,and 20-year-old stands respectively. There were significant linear relationships between chlorophyll contents in needle during bud flush,the first and secondfastgrowing season and corresponding nitrogen concentration (r=0.86, 0.76, and 0.81 respectively). Chlorophyll content can be used as a physiological index to evaluate nitrogen nutritional status in Chinese fir plantations. Arginine and ammonia nitrogen contents in current needles and twigs on the good sites were higher than those on the poor sites. Arginine contents in current needle were 47.55, 43.37, and 29.44mg/100gf. W. during the second fast-growing season in the stands of 5, 10,and 20-year-old respectively,while it were 28.16, 26.42,and 14.95mg/100gf.w. on the poor sites.

Key words: Chinese fir, chlorophyll arginine, ammonia nitrogen, stand age, site quality, tree class