垃圾填埋场周边桉树光合生理特性研究

为了解垃圾填埋场环境下植物的光合适应性,利用LI-6400便携式光合测定仪,以呼马山森林公园为对照,对位于昆明市东郊垃圾填埋场和对照区的直杆桉Eucalyptus maideni进行了光响应与光合日进程的测定。结果表明:填埋场直杆桉的净光合速率随光强的增加先增加后稍有下降并趋于稳定,光抑制不明显;对照的净光合速率随光强的增加先增加后缓慢下降;在相同光照强度下,填埋场直杆桉的净光合速率、蒸腾速率始终高于呼马山对照的,说明直杆桉可通过提高自身的光合能力和蒸腾速率来适应填埋场的特定环境。胞间CO2浓度随光强的增加先下降后上升,与净光合速率大体呈相反变化;蒸腾速率随光强变化的趋势与气孔导度变化相一致。另外,填埋场直杆桉净光合速率日变化呈单峰曲线,无明显"午休"现象,其变化趋势与蒸腾速率、气孔导度的大体相同。对照的净光合速率、气孔导度、蒸腾速率与填埋场的变化趋势相似,但变化幅度较少。在自然条件下,填埋场直杆桉的净光合速率和蒸腾速率仍明显高于呼马山对照的。

Photosynthetic physiological characteristics of Eucalyptus around garbage landfill

To understand the adaptability of plant photosynthesis in landfill site,the light responses and diurnal changes of Eucalyptus photosynthesis were measured in garbage landfill in the eastern suburb of Kunmimg and Huma Mountain forest park by LI-6400 portable photosynthetic system.The results showed that with the increase of light intensity,the net photosynthetic rate of Eucalyptus in landfill site increased,reached the highest point,then decreased gradually and tended to be stable,the photo inhibition was not obvious.In Huma Mountain forest park,the net photosynthetic rate also increased and then decreased gradually.But the net photosynthetic rate and transpiration rate were always lower than that in in landfill site,which indicated that Eucalyptus might adapt to special environment through the increase of net photosynthetic rate and transpiration rate.The change of intercellular CO2concentration was opposite with the net photosynthetic rate,but the change of transpiration rate was similar with stomatal conductance.In addition,the diurnal variation of Eucalyptus photosynthetic rate in landfill site was a single-peak curve without midday rest phenomenon,which was similar with transpiration rat and stomatal conductance.However,the change range was smaller in Huma Mountain.In the natural conditions,the net photosynthetic rate of Eucalyptus in landfill site was significantly higher than that of Huma Mountain.