阿拉善荒漠草原梭梭与白刺光合特征比较研究

为比较阿拉善荒漠草原区2种优势植物梭梭(Haloxylon ammodendron)和白刺(Nitraria tangutorum)的光合生理特征差异性,在2008年7月下旬利用Li-6400便携式光合仪测定了研究区内梭梭与白刺2种植物样株的光合作用日变化特征和光响应曲线,并采用非直线双曲线模型对光响应曲线进行了拟合分析。结果表明:在8:00-18:00的测定范围内,梭梭和白刺的光合速率日变化特征表现为单峰型曲线,光合速率的日峰值分别出现在12:00和11:00;梭梭的日平均净光合速率、水分利用效率均大于白刺;梭梭的最大净光合速率(Pnmax)、光补偿点(Lcp)和光饱和点(Lsp)均明显大于白刺。

A Comparative Study on Photosynthetic Characteristics of Haloxylon ammodendron and Nitraria tangutorum on Temperate steppa subdesert in Alashan

Photosynthesis is one of the important activities which affected plant growth.In order to discovery the difference of photosynthetic characteristics between Haloxylon ammodendron and Nitraria tangutorum,an open gas exchange system,Li-6400 Portable Photosynthesis System,was used to study the characteristics of Haloxylon ammodendron and Nitraria tangutorum on the photosynthesis daily change and light-response curve in July 2008 in Alashan.The results showed that during 8 o'clock to 18 o'clock,the daily change of the net photosynthetic rate of Haloxylon ammodendron and Nitraria tangutorum appeared as single-peak curve and reached the daily peak value at 12 o'clock and 11 o'clock respectively.The net photosynthetic rate of daily average value and water use efficiency of Haloxylon ammodendron were higher than those of Nitraria tangutorum.Analyzed the light-response curve by the non-rectangular hyperbola model,the results showed that the maximum net photosynthetic rate,light saturation point(Lsp) and light compensation point(Lcp) of Haloxylon ammodendro were higher than those of Nitraria tangutorum.