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(400 microliters.L-1) and elevated (700 microliters.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.