Gorissen A, Joosten N N, Smeulders S M, Van Veen J A
DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO), P.O. Box 14, 6700 AA Wageningen, The Netherlands.
Tree Physiol. 1994 Jun;14(6):647-57. doi: 10.1093/treephys/14.6.647.
Effects of ozone and soil water availability on partitioning and translocation of assimilates were studied in three-year-old Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings exposed, in separate experiments, to 0 and 106 or 0 and 514 micro g m(-3) ozone for 8 h day(-1) for 9 days. The dynamics of carbon from assimilated (14)CO(2) were followed. No interactions between ozone and soil water content were observed. Total net uptake of carbon was reduced by low soil water content, but was unaffected by ozone. Both ozone and low soil water content increased the amount of (14)C-photosynthates retained in the current-year needles. Total starch content in old and current-year needles was unaffected by ozone, but was reduced by low water availability. Translocation of carbon to the root-soil compartment was additively affected by ozone and low soil water content. The results suggest that dry periods in summer combined with high ozone concentrations cause the greatest reduction in the supply of carbon compounds to the root-soil compartment.
在单独的实验中，将三年生花旗松（Pseudotsuga menziesii [Mirb.] Franco）幼苗每天8小时、持续9天暴露于0和106或0和514微克/立方米的臭氧环境中，研究了臭氧和土壤水分有效性对同化物分配和转运的影响。追踪了同化的¹⁴CO₂中碳的动态变化。未观察到臭氧与土壤含水量之间的相互作用。低土壤含水量降低了碳的总净吸收量，但臭氧对其没有影响。臭氧和低土壤含水量均增加了当年针叶中保留的¹⁴C光合产物的量。老针叶和当年针叶中的总淀粉含量不受臭氧影响，但低水分有效性使其降低。臭氧和低土壤含水量对碳向根 - 土壤部分的转运产生累加影响。结果表明，夏季干旱期与高臭氧浓度相结合会导致向根 - 土壤部分供应的碳化合物减少最多。
