CO_2浓度升高对长白山三种树木幼苗叶碳水化合物和氮含量的影响

Effect of elevated CO_2 concentration on carbohydrate and nitrogen contents in seedlings foliage of three tree species in Changbai Mountain.

研究了持续 3个生长季高浓度CO2 处理的长白山主要树种红松、长白赤松和水曲柳幼苗叶 (片 )的蔗糖、果糖、可溶性总糖、淀粉及全氮含量变化 .结果表明 ,前两个生长季 70 0 μmol·mol-1CO2 处理 ,促进了水曲柳和长白赤松幼苗的淀粉累积 ,70 0和 5 0 0 μmol·mol-1CO2 却使红松幼苗的全N含量明显降低 .第三个生长季高浓度CO2 处理的第一周和第二周 ,红松和水曲柳幼苗的淀粉含量增加 ,全N含量降低 ,第八周时 ,水曲柳仍维持原来的变化趋势 .第三个生长季高浓度CO2 处理 ,并未使长白赤松的C、N含量有明显的增减 .CO2 浓度影响了碳水化合物在叶 (片 )

The contents of sucrose, fructose, soluble total sugar, starch and total nitrogen were analyzed in seedlings of Pinus koraiensis, Pinus sylvestriformis and Fraxinus mandshurica grown for three growing seasons in open-top chambers in Changbai mountain under elevated CO 2 (700, 500 μmol·mol -1)and ambient CO 2 (350 μmol·mol -1) concentrations. The results showed that in the first two growing seasons the treatment of 700 μmol·mol -1 CO 2 accumulated the contents of starch in Pinus sylvestriformis and Fraxinus mandshurica seedlings, while total nitrogen content significantly decreased in Pinus koraiensis seedlings under 700 and 500 μmol·mol -1 CO 2. The content of starch increased and the content of total nitrogen decreased in Pinus koraiensis and Fraxinus mandshurica seedlings grown under 700,500 μmol·mol -1 CO 2 at the first two weeks in the third growing season. The change of starch and total nitrogen in Fraxinus mandshurica at the eighth week was similar to the first and second week. There was no significant increase or decrease of C and N content in Pinus sylvestriformis at the third growing season. CO 2 concentration affected the forms of carbohydrate accumulation in foliage.