土壤水分对辽东栎等树种光合速率和叶绿素荧光特性的影响

THE EFFECTS OF SOIL WATER CONTENT ON PHOTOSYNTHETIC RATE AND CHLOROPHYLL FLUORESCENCE PARAMETERS OF Spiraea salicifolia ETC.TREES

本文选择大青山水磨林场绣线菊等树种作为实验材料,使用LI-6400便携式光合测定系统测定盆栽幼树不同土壤水分状况下的净光合速率和叶绿素荧光参数变化。结果指出,在土壤含水量较大时,随着土壤含水量变化,净光合速率和叶绿素荧光参数基本不变,净光合速率和叶绿素荧光参数随土壤水分减少而下降的初始下降点的土壤含水量因树种和指标不同而有差异。净光合速率初始下降点的土壤含水量可作为树木初始土壤水分胁迫评价指标,绣线菊、荀子、辽东栎三种被试树木初始土壤水分胁迫土壤含水量分别为11.12%、13.89%和15.63%。Fv/Fm初始下降点的土壤含水量可作为树木严重土壤水分胁迫评价指标,进而可评价树木对土壤水分胁迫的适应性。绣线菊、荀子、辽东栎三种被试树木Fv/Fm初始下降点的土壤含水量分别为7.11%5、.43%和4.43%,辽东栎对土壤水分胁迫的适应性较强,绣线菊较弱。

In this paper,Spiraea salicifolia,Cotoneaster acutifolia,Quercus liaotungensis in Daqingshan Shuimo Forest Farm were selected the test materials.Net photosynthetic rate and Chlorophyll fluorescence parameters under different soil moisture conditions were measured by portable photosynthetic measuring system LI-6400.The result showed that the net photosynthetic rate and Chlorophyll fluorescence parameters does not have the obvious change when the soil moisture changes in higher soil moisture conditions,but they is decreased with the decreasing of soil moisture content in lower soil moisture conditions.It indicated that the critical value of the soil moisture content which they declined initially with the decreasing of soil moisture content has much difference in species and in the indexes.The soil moisture content that the net photosynthetic rate decreases initially is as a index to evaluate the initial soil water stress.In the meantime,the critical value of soil moisture content that with the decreasing of soil moisture content,those of Spiraea salicifolia,Cotoneaster acutifolia and Quercus liaotungensis isrespectively 11.12%,13.89% and 15.63%.The soil moisture content that Fv/Fm decreases initially is as a index to evaluate the serious soil water stress,those of those of Spiraea salicifolia,Cotoneaster acutifolia and Quercus liaotungensis isrespectively 7.11%,5.43% and 4.43%,it is tant Quercus liaotungensis is strongest adaptable to soil water stress,and Spiraea salicifolia is lest.