Evaluation of the function of woody plants for environmental control under elevated atmospheric CO_2

研究了CO2浓度升高对木本植物CO_2和H_2O气体交换的影响。本文介绍了木本植物在大气和高浓度CO_2浓度下气体交换的研究结果：(1)CO_2浓度和光照强度对幼树光合作用和蒸腾速率的影响；(2)CO_2浓度升高对常绿树木水分胁迫的抑制作用；(3)CO_2浓度升高对树木幼苗热平衡和蒸腾作用的影响；(4)用田间小室测定木本植物对气体污染物的吸收速率的方法；(5)树木对气体污染物的吸收速率的季节变化；(6)CO_2浓度对木本植物气体污染物吸收速率的短期影响，不同树种的气体交换速率差异较大。目前，蓝桉和马占相思因其在造林中的适宜性而备受关注。随着CO_2浓度水平的增加，它们的CO_2吸收增加，但蒸腾速率在此条件下显著降低。虽然通过使用这种树木可以提高水分利用系数，因为它们在水资源有限的地区高效利用水资源，并在这种条件下生长和茁壮成长，但也应该记住，它们的低蒸腾速率也会影响热环境。

This study investigated the changes in CO_2 and H_2O gas exchange of woody plants due to increases in CO_2 concentrations. This report contains information obtained from the study on gas exchange of woody plants in ambient and elevated CO_2 concentrations :(1) effects of CO_2 concentration and light intensity on photosynthesis and transpiration rate of young trees,(2) inhibition of water stress in evergreen trees under elevated CO_2 concentration,(3) effects of elevated CO_2 concentration on heat balance and transpiration of tree seedlings,(4) method for measurement of sorption rates of gaseous air pollutants by woody plants with a field chamber,(5) seasonal change in sorption rates of gaseous air pollutants by trees,(6) short term effects of CO_2 concentration on gaseous air pollutants sorption rates of woody plants,Depending on the species of tree, the gas exchange rate varied greatly. At present, Eucalyptus globulus and Acacia mangium are gaining attention due to their suitability for use in afforestation. As CO_2 concentration levels increased, their CO_2 uptake increased, however the decrease of the transpiration rate under these conditions was remarkable. Although it is possible that through the use of such trees the water usage coefficient can improve due to their highly efficient use of water in areas of limited water resources and their ability to grow and thrive under such conditions, it should also be remembered that their low transpiration rate will also influence the thermal environment.