黄刺玫叶片光合生理参数的土壤水分阈值响应及其生产力分级  

Threshold effect of soil moisture on photosynthetic and physiological parameters in Rosa xanthina L. and its photosynthetic productivity classification

作　　者：张淑勇[1] 夏江宝[2] 张光灿[1] 周泽福[3] 

机构地区：[1]山东农业大学林学院、山东省土壤侵蚀与生态修复重点实验室,泰安271018 [2]山东省黄河三角洲生态环境重点实验室,滨州学院,滨州256602 [3]中国林业科学研究院林业研究所、国家林业局林木培育重点实验室,北京100091

出　　处：《生态学报》2014年第10期2519-2528,共10页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201104068);国家自然科学基金(31100196,31100468);山东省优秀中青年科学家科研奖励基金(BS2013NY010)

摘　　要：在半干旱黄土丘陵区,以3年生天然次生灌木黄刺玫为材料,研究了叶片光合生理参数对土壤水分(RWC)的响应特征及光合生产力分级。结果表明:当RWC在33.8%—81.3%时,叶片净光合速率(Pn)和蒸腾速率(Tr)的变化曲线为明显的双峰曲线;上午阶段(11:00时之前)Pn的下降主要是气孔限制引起的,下午以非气孔限制为主;随着RWC的增加,Pn、Tr第1峰值出现的时间延后;在此水分范围内,Pn日均值一直维持在较高水平,Pn最高值((8.5±1.8)mmol·m-2·s-1)出现在RWC为71.7%时。水分利用效率(WUE)对RWC的响应有所差异,当RWC大于47.1%时,WUE呈不明显的双峰曲线,第1峰值出现在13:00时,并且前后时段WUE变化不大。RWC为47.1%时,WUE维持在最高水平,日均值为(2.72±0.59)μmol/mmol。根据Pn、Tr、WUE和RWC的定量分析,以及从黄土丘陵区生态、经济效益同时考虑,适合黄刺玫生长的RWC在33.8%—71.7%之间。以光合生理参数为指标对黄刺玫土壤水分有效性及生产力进行分级与评价,确定RWC>90.4%或RWC<33.8%时为"中产中效水";RWC在71.7%—81.3%和47.1%—71.7%时分别为"高产中效水"和"高产高效水",!其中RWC在57.4%左右时为"最优产效水";RWC在18.8%—26.5%时为"低产低效水"。The loess plateau region is an extremely adverse eco-environment in China, and drought and water shortage are the most critical ecological factors restricting the development of local economy, vegetation restoration and the production of agriculture and forestry. With increasing water-resource crises and drying hazards, some tree species during the process of farmland to forest project grew slowly and even to dead on the parts of loess plateau; thus, the selection of tree species is critical for vegetation restoration, and the development of soil and water conservation plantation composed of shrubs, grassesand arbors is significant for accelerating afforestation and soil and water conservation.However, complications such as single tree species and unreasonable tree species selection and arrangement in some areas have hindered the farmland to forest conversion and artificial vegetation construction in the loess plateau region. These complications reflect the fact that little is known about the local shrub species, and there is a lack of researches concerning the relationship between plants and water. In this study, Li-Cor6400 portable photosynthesis system was used to investigate the threshold effect of net photosynthetic rate （P.）, transpiration rate （ Tr） , water use efficiency （ WUE）, stomata conductance （ Gs ）, intercellular CO2 concentration （ Ci ） and stomata limitation （ Ls ） in leaves of three-year-old naturally regenerated Rosa xanthina L. shrubs in the loess hilly region, to soil water content obtained through artificial water supply and natural consumption, and its photosynthetic productivity was classified. The results showed that the diurnal changes of Pn and Tr showed an evident double-peaked curve when the relative water content （RWC） was in the range of 33.8%--81.3%; the reduction of P was mainly caused by stomatal limitation in the morning （before 11：00） and non-stomatal limitation in the afternoon （after 13：00）. The time when the first peak value of P and

关 键 词：阈值效应 土壤水分 生产力分级 黄刺玫 

分 类 号：S793.9[农业科学—林木遗传育种]