【摘要】 研究了分布于浙江建德的亚热带常绿阔叶林生态系统的Mg的积累和循环.结果表明:群落各代表种类的Mg浓度为0.028%~0.265%,变幅较大.新的器官和个体中积累了较多的Mg.优势种青冈体内Mg浓度的季节变化不明显.鲜叶和鲜枝中的Mg浓度比枯叶和枯枝高.降水通过林冠时有部分Mg被淋溶出来.Mg在群落中现存量为89.96 kg/hm2,死地被层中积累量为15.62 kg/hm2,土壤(A0-B层)中储存量为39 840 kg/hm2.群落中Mg的存留量为11.64 kg/(hm2.a);归还量为8.52 kg/(hm2.a),其中大部分通过凋落物和穿透水归还(占99%);吸收量为20.16 kg/(hm2.a).降水输入了2.67 kg/(hm2.a)的Mg.更多还原

【Abstract】 The mechanism for accumulation and cycling of Mg in a subtropical evergreen broad-leaved forest in Zhejiang Province was elucidated in this paper.The concentration of Mg in representative species was 0.028%-（0.265%）.The proportions of Mg in new organs and young individuals were higher.Seasonal dynamics of the concentration of Mg in the dominant species-Cyclobalanopsis glauca was not evident.The concentration of Mg in fresh leaves and branches was higher than that in fallen ones.A proportion of Mg had leached from the canopy by incident precipitation.The standing crop of Mg in community was 89.96 kg/hm²,in litter layer was 15.62 kg/hm²,and in soil（A₀-B） was 39 840 kg/hm².Retention of Mg was 11.64 kg/（hm²·a）.Return of Mg was 8.52 kg/（hm²·a）,in which via litterfall occupied about 99%.Uptake of Mg was 20.16 kg/（hm²·a）.Annual input of Mg through precipitation was 2.67 kg/（hm²·a）.更多还原