【摘要】 对干旱季节田间板栗净光合日变化特征及主要影响因子的研究结果表明，在阴天， 板栗净光合日变化呈单峰型， 中午的光强、叶温和叶水势均处于较适宜状态，净光合达到最大值， 而晴天的净光合日变化呈双峰型， 上午１０∶００～１１∶００ 达最大值， 在中午， 随着光强、叶温增高， 叶水势降低， 净光合急剧下降， １５∶００ 左右降至低谷， 为第１ 峰值的４０％ ～５０％ 。在下午， 光强、叶温和叶水势等因子有所改善，光合在１７∶００～１８∶００ 达第２ 个峰值。高光强、高叶温和低叶水势是导致光合午休的主要原因。栗园浇水并保持５５％ ～８５％ 土壤相对含水量能有效改善植株环境条件， 提高光能利用。更多还原

【Abstract】 The Pn diurnal fluctuations and the main affecting factors of field grown Chinese chestnut ( Castanea molli ssima ,Bl.) in drought season were studied,the results revealed that Pn diurnal fluctuation was single-peak in overcast weather condition,while,under fair weather condition,showed a typical 2 peak variation with a significant phenomenon of “noon slump”.By irrigation experiments and comprehensive analysis,the key causes of Pn “noon slump”were disadvantageous LI,Tl and LWP with 55 85% of SWC,the orchard condition was obviously improved,and showed the best photosyn thetic capacity.更多还原