高CO2浓度对长白山阔叶红松林主要树种的影响

组成长白山阔叶红松林的主要树种红松、云杉、落叶松、大青杨、白桦、椴树、水曲柳和色木的幼树,盆栽于模拟自然光照和人工调节CO₂浓度为700μl·L^-1、400μl·L^-1的气室内两个生长季,以生长在400μl·L^-1下的幼树为对照组,在各自生长条件下测定,高CO₂浓度下生长的红松、云杉、落叶松、大青杨、白桦、椴树、水曲柳和色木的高生长比对照组的幼树提高10%～40%.高CO₂浓度的幼树与对照CO₂下的幼树相比各树种蒸腾速率升降不一,但水分利用效率均有不同程度的提高,不同树种的可溶性糖和叶绿素含量对高CO₂浓度反应不一,反映出幼树对高CO₂浓度适应的复杂性.长期高CO₂浓度环境下生长的阔叶树对CO₂变化反应较针叶树敏感,供试树种均发生光合驯化现象.

Effect of elevated CO2 concentration on growth of dominant tree species in pine broadleaf forest of Changbai mountain

Potted saplings of Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica, and Acer mono,the eight dominant species in the Korean pine broadleaf forest at Changbai Mountain,were grown in open top chambers with ambient(400μl·L^-1) and elevated (700μl·L^-1) CO₂ concentration under natural sunlight for two growing seasons.The average height growth of these eight species under elevated CO₂ increased by 10%～40%, compared with the control at ambient CO₂. The response of transpiratory rate to the higher CO₂ concentration was different among the species,and the water use efficiency of the saplings of the 8 species growing under elevated CO₂ concentration was higher than that under ambient CO₂. Soluble sugar and chlorophyll contents were not related to the CO₂ concentration under which the saplings grew, indicating that the complicacy was existed in the acclimation of tree species to high CO₂ concentration. The response of broad leaved tree species to the elevated CO₂ concentration was more sensitive than that of conifer tree species.Saplings of all tree species showed a photosynthetic acclimation to higher CO₂ under long term elevated CO₂ concentration.