不同光照和水分条件对火炬树的生理生态功能的影响

Effects of Different Light and Water Conditions on Physiological and Ecological Functions of Rhus typhina

本文以火炬树(Rhus typhina)一年生实生苗为试材,采用温室栽培方式,分别设置2个光照梯度(100%光照、50%光照)和3个水分梯度(75%、50%、25%的田间持水量),研究不同光照和水分条件下火炬树的生理生态学响应机制。结果表明:(1)水分胁迫抑制火炬树生长,100%光照条件下,25%的田间持水量处理的火炬树的株高相对生长速率、基径相对生长速率、冠幅相对生长速率、总生物量、光合氮利用效率较75%田间持水量处理下分别降低63.10%、37.24%、45.44%、46.67%、33.66%,而比叶面积、根冠比、叶片含氮量分别增加22.42%、45.94%、37.74%,另外PSⅡ的最大光化学效率、叶片含水量、净光合速率变化不显著;(2)50%光照处理下,叶片比叶面积、含水量、总叶绿素含量以及叶面氮含量较100%光照处理下增加,净光合速率、蒸腾速率、气孔导度以及水分利用效率下降,最大下降幅度为32.87%、40.00%、17.04%和19.05%,其他指标变化不明显。火炬树在受到光照和水分环境变化时,可以通过调整生长和氮元素利用来适应环境的变化,具有较强的适应能力,建议作为干旱较为严重或光照较弱的荒山、荒地绿化。

Using the annual seedlings of Rhus typhina as the test material,two light gradients(100%light,50%light)and three water gradients(75%,50%,25%field water capacity)were set up respectively in greenhouse cultivation mode to study the physio-ecological response mechanism of R.typhina under different light and water conditions.The results showed that:(1)Water stress inhibited the growth of torch tree.Under 100%light conditions,the relative growth rate of plant height,relative growth rate of basal diameter,relative growth rate of crown width,total biomass,and photosynthetic nitrogen use efficiency of torch tree treated with 25%field water capacity decreased by 63.10%,37.24%,45.44%,46.67%,and 33.66%,respectively,while the specific leaf area,root-shoot ratio,and leaf nitrogen content increased by 22.42%,45.94%,respectively 37.74%,in addition,the maximum photochemical efficiency,leaf water content and net photosynthetic rate of PSⅡdid not change significantly;(2)Under 50%light treatment,the specific leaf area,water content,total chlorophyll content and leaf nitrogen content of leaves increased compared with that under 100%light treatment,while the net photosynthetic rate,transpiration rate,stomatal conductance and water use efficiency decreased,with the maximum decline of 32.87%,40.00%,17.04%and 19.05%,and other indicators did not change significantly.Conclusion:Torch tree can adapt to the changes of environment by adjusting its growth and nitrogen utilization when it is exposed to the changes of light and water environment,and has strong adaptability.It is recommended to be used as afforestation of barren mountains and wastelands with severe drought or weak light.