Gorissen A, Kuikman P J, VAN DE Beek H
DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO), P.O. Box 14, 6700, AA Wageningen, The Netherlands.
New Phytol. 1995 Feb;129(2):275-282. doi: 10.1111/j.1469-8137.1995.tb04297.x.
In this study the impact of an elevated CO level on allocation of assimilates and water use efficiency of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] was investigated. Juvenile Douglas firs were exposed to a long-term treatment at 350 and 700 μ 1 CO for 14 months and subsequently crosswise transferred to phytotrons for a short-term treatment with 350 and 700 μ l CO for 4 wk in an atmosphere continuously labelled with CO . No interactive effects on total net uptake of CO between long-term treatment and short-term treatment were observed. The short-term treatment with 700 μ 1 CO increased the total net uptake of CO by 22%, compared with the 350 μ l CO treatment. The long-term pretreatment did not affect the total net uptake, suggesting that photosynthetic acclimation had not occurred. However, expressed per unit of needle mass a 14% reduction was observed in the trees pretreated at 700 μ l CO . This was not because of a reduced sink strength of the root system. This reduced uptake per unit of needle mass after long-term treatment may have implications for carbon storage in forest ecosystems. The results showed that an initial growth stimulation can eventually be annulled by developing physiological or morphological adaptions. CO in the root/soil respiration increased in the short-term treatment with 700 μ l CO , indicating a stimulated use of current carbon compounds either by roots or microorganisms. The water use efficiency during the short-term treatment with 700 μ l CO increased by 32 %, but was not affected by the long-term pretreatment. Water use per unit needle mass during the short-term treatment was decreased both by the short-term treatment and by the long-term pretreatment by about 15%. Some of the observed effects appeared to be persistent, such as decreased water use per unit needle mass, whereas others, stimulation of total net CO uptake and water use efficiency, were transient.
在本研究中，调查了高浓度一氧化碳（CO）水平对花旗松[北美黄杉（Pseudotsuga menziesii (Mirb.) Franco）]同化物分配和水分利用效率的影响。将幼年花旗松在350和700 μl CO条件下进行14个月的长期处理，随后横向转移至人工气候箱，在持续标记有CO的大气中用350和700 μl CO进行4周的短期处理。未观察到长期处理和短期处理之间对CO总净吸收量有交互作用。与350 μl CO处理相比，700 μl CO的短期处理使CO总净吸收量增加了22%。长期预处理并未影响总净吸收量，这表明未发生光合适应。然而，以单位针叶质量表示，在700 μl CO预处理的树木中观察到有14%的下降。这并非由于根系库强度降低。长期处理后单位针叶质量吸收量的降低可能对森林生态系统中的碳储存有影响。结果表明，最初的生长刺激最终可能会因生理或形态适应的发展而被抵消。在700 μl CO的短期处理中，根/土壤呼吸中的CO增加，表明根系或微生物对当前碳化合物的利用受到刺激。700 μl CO短期处理期间的水分利用效率提高了32%，但不受长期预处理的影响。短期处理期间单位针叶质量的用水量在短期处理和长期预处理下均下降了约15%。一些观察到的影响似乎是持久的，例如单位针叶质量用水量的减少，而其他影响，如总净CO吸收量的刺激和水分利用效率，则是短暂的。
