北京山区辽东栎林中几种木本植物光合作用对CO2浓度升高的响应

 为揭示我国暖温带地区辽东栎群落若干优势植物光合作用随CO2浓度升高而变化的特点，用自行设计的同化室装置对自然生长状态下的辽东栎(Quercus liaotungensis KOidz．)、大叶白蜡(Fraxinus mandshurica Rupr．)、蒙椴(Tilia mongolica Maxim．)、五角枫(Acer mono Maxim．)，以及优势灌木六道木(Abelia biflora Turcz．)、毛榛(Corylus mandshurica Maxim．)等6种木本植物进行升高CO2浓度处理，测定了这几种植物净光合速率的变化。加倍CO2浓度对6种植物的光合作用有不同程度的促进作用，净光合速率增加的程度从37％到93％不等，以辽东栎受到的促进作用最大，六道木最小，平均增加75％。净光合作用随CO2浓度升高而增加的程度中乔木种类略高于灌木种类。在夏季和秋季进行的日动态测定都表现出加倍CO2浓度对6种木本植物净光合速率的明显的促进作用。

PHOTOSYNTHETIC RESPONSE OF SIX WOODY SPECIES TO ELEVATED CO_2 IN QUERCUS LIAOTUNGENSIS FOREST IN THE BEIJING MOUNTAINOUS AREAS

Using specially designed chambers and an infrared gas analyzer, we examined the photosynthetic responses of six woody species to elevated CO2, from 325 μmol·mol-1 to 650 μmol·mol-1. Six temperate forest woody species under natural growth conditions in the Quercus liaotungensis forest in Beijing Mountainous Areas were tested: Quercus liaotungensis koidz. , Fraxinus mandshurica Rupr. , Tilia mongolica Maxim. , Acer mono Maxim. , Abelia biflora Turcz. and Corylus mandshurica . The results showed that the six species displayed variable degrees of enhancement in net photosynthetic rates to elevated CO2, from 37% (Abelia biflora Turcz. ) to 93% (Quercus liaotungensis koidz. ), with an average value of 75%. Shrub species were less affected than tree species. Remarkable enhancement in net photosynthetic rates with elevated CO2 were found during the diurnal courses in both summer and autumn.