CO_2浓度倍增对苗木生长和养分含量的影响

在CO2浓度倍增条件下,研究了油松、侧柏、元宝枫和刺槐的苗高、地径、叶生长和养分含量等方面的变化。结果表明,CO2浓度倍增下苗木的苗高和地径均比对照的高;油松、侧柏和刺槐的叶生长明显大于对照的,而元宝枫变化不显著;各植物苗木的暗呼吸速率、土壤氮含量都比对照的小;磷含量的变化很小;侧柏的钾含量比对照的降低了56.70%,油松、刺槐和元宝枫的钾含量分别比对照的升高了60.13%、23.32%和0.69%,而幼嫩和成熟叶片中氮、磷和钾含量的变化没有显著规律性,其影响机理有待进一步研究。

Effects of doubled CO2 concentration on seedling growth and nutrient contents

The growth of Pinus tabulaeformis,Platycladus orientali,Acer truncatum and Robinia pseudoacacia under doubled CO2 concentration and contrasts were investigated and compared.The seedling height and root diameter respectively increased under doubled CO2 concentration compared with those of contrast.Except A.truncatum with unobvious change,the leaf area of Pinus tabulaeformis,Platycladus orientali and R.pseudoacacia all increased under doubled CO2 concentration,respectively 19.23%,11.11% and 68% more than that of contrast.Both the dark respiration rate and nitrogen content in soil of the seeding decreased.Phosphorus content all changed a little in the 4 tree species.The potassium content of Platycladus orientali decreased by 56.70%,while Pinus tabulaeformis,R.pseudoacacia,and A.truncatum increased by 60.13%,23.32% and 0.69% than that of contrast;The content of nitrogen,phosphorus and potassium of young leaf and mature leaf did not have obvious change trend,and further research on their change mechanism should be carried out in the future.